JP7643132B2 - Drive unit - Google Patents

Description

The present invention relates to a drive device.

There is a known drive unit that cools a rotating electric machine by supplying oil stored in a case that houses a power transmission mechanism to the rotating electric machine. For example, Patent Document 1 describes a drive unit for a vehicle that discharges oil from a cooling pipe to the rotating electric machine.

JP 2019-129608 A

In the drive device described above, a partition wall is provided to separate the storage space in which the rotating electric machine is housed from the storage space in which the power transmission mechanism is housed. In Patent Document 1, the bearings supporting the rotor shaft of the rotating electric machine and the bearings supporting the rotating shaft of the power transmission mechanism are held in the same partition wall. This makes it difficult to independently separate the case housing the rotating electric machine from the case housing the power transmission mechanism. This creates a problem in that when the rotating electric machine or the power transmission mechanism breaks down, it is difficult to separate only the broken device, making it difficult to replace or repair the device.

In view of the above circumstances, one of the objects of the present invention is to provide a drive device that can easily separate the motor and the transmission mechanism.

One aspect of the drive device of the present invention includes a motor having a rotor rotatable around a central axis and a stator covering the radial outside of the rotor, a transmission mechanism connected to the motor, a motor housing that houses the motor, and a housing having a transmission mechanism housing fixed to one axial side of the motor housing and housing the transmission mechanism and a first fluid, and a first flow path through which the first fluid flows. The first flow path has a supply path that supplies the first fluid housed inside the transmission mechanism housing to the motor, and a first recovery path that returns the first fluid supplied to the motor to the inside of the transmission mechanism housing. The motor housing has a first housing member fixed to the transmission mechanism housing and a second housing member fixed to the other axial side of the first housing member. The transmission mechanism housing has a third housing member fixed to the first housing member and a fourth housing member fixed to one axial side of the third housing member. The first housing member has a first opposing wall portion that faces the third housing member in the axial direction, and a bearing holding portion that is provided on the first opposing wall portion and holds a bearing that rotatably supports the rotor. The third housing member has a second opposing wall portion that faces the first opposing wall portion in the axial direction. The first opposing wall portion has a first opening that opens to the inside of the motor housing and the outside of the motor housing. The second opposing wall portion has a second opening that opens to the inside of the transmission mechanism housing and the outside of the transmission mechanism housing. At least a portion of the first recovery path is formed by the first opening and the second opening.

According to one aspect of the present invention, the motor and the transmission mechanism in the drive device can be easily separated independently.

FIG. 1 is a cross-sectional view of a drive device according to an embodiment, as viewed from above. FIG. 2 is a cross-sectional view of the drive device according to the embodiment, as viewed from the rear side. FIG. 3 is a perspective view illustrating a portion of a first housing member of the motor housing of the embodiment. FIG. 4 is a perspective view illustrating a portion of a second housing member of the motor housing of the embodiment. FIG. 5 is a cutaway perspective view of a portion of a housing of one embodiment. FIG. 6 is a view of the first opening and the second opening of the embodiment as viewed from one axial side. FIG. 7 is a cross-sectional perspective view showing a portion of the oil supply passage of the embodiment. FIG. 8 is a cross-sectional view of a portion of a housing in one embodiment. FIG. 9 is a perspective view of a portion of a housing of one embodiment. FIG. 10 is a view of the first housing member of the motor housing according to one embodiment, as viewed from the other axial side. FIG. 11 is a perspective view showing a positioning portion according to one embodiment. FIG. 12 is a perspective view showing a first trough portion of one embodiment. FIG. 13 is a view of the second groove portion of one embodiment as viewed from one axial side. FIG. 14 is a cross-sectional perspective view illustrating a portion of a motor housing of one embodiment. FIG. 15 is a cross-sectional view showing a portion of the second flow path of one embodiment.

In the following description, the vertical direction is defined based on the positional relationship when the drive device of the embodiment is mounted on a vehicle positioned on a horizontal road surface. In other words, the relative positional relationship in the vertical direction described in the following embodiment only needs to be satisfied when the drive device is mounted on a vehicle positioned on a horizontal road surface.

In the drawings, the XYZ coordinate system is appropriately shown as a three-dimensional orthogonal coordinate system. In the XYZ coordinate system, the Z axis direction is the vertical direction. The +Z side is the upper side in the vertical direction, and the -Z side is the lower side in the vertical direction. In the following description, the upper side in the vertical direction is simply called the "upper side", and the lower side in the vertical direction is simply called the "lower side". The X axis direction is a direction perpendicular to the Z axis direction and is the front-rear direction of the vehicle on which the drive unit is mounted. In the following embodiments, the +X side is the front side of the vehicle, and the -X side is the rear side of the vehicle. The Y axis direction is a direction perpendicular to both the X axis direction and the Z axis direction, and is the left-right direction of the vehicle, i.e., the vehicle width direction. In the following embodiments, the +Y side is the left side of the vehicle, and the -Y side is the right side of the vehicle. The front-rear direction and the left-right direction are horizontal directions perpendicular to the vertical direction.

The positional relationship in the front-rear direction is not limited to that in the following embodiment, and the +X side may be the rear side of the vehicle, and the -X side may be the front side of the vehicle. In this case, the +Y side is the right side of the vehicle, and the -Y side is the left side of the vehicle. In this specification, "parallel direction" also includes a substantially parallel direction, and "perpendicular direction" also includes a substantially perpendicular direction.

The central axis J1, which is shown in the appropriate figures, is a virtual axis that extends in a direction that intersects with the vertical direction. More specifically, the central axis J1 extends in the Y-axis direction that is perpendicular to the vertical direction, that is, in the left-right direction of the vehicle. In the following description, unless otherwise specified, the direction parallel to the central axis J1 will be simply referred to as the "axial direction", the radial direction centered on the central axis J1 will be simply referred to as the "radial direction", and the circumferential direction centered on the central axis J1, that is, around the axis of the central axis J1, will be simply referred to as the "circumferential direction". In each of the following embodiments, the left side (+Y side) will be referred to as the "one axial side", and the right side (-Y side) will be referred to as the "other axial side".

The arrow θ shown in the appropriate figures indicates the circumferential direction. In the following explanation, the side of the circumferential direction that progresses counterclockwise around the central axis J1 as viewed from one axial side (+Y side), i.e. the side to which the arrow θ points (+θ side), is referred to as the "one circumferential side," and the side of the circumferential direction that progresses clockwise around the central axis J1 as viewed from one axial side, i.e. the opposite side to the side to which the arrow θ points (-θ side), is referred to as the "other circumferential side."

The drive device 100 of this embodiment shown in Figures 1 and 2 is a drive device that is mounted on a vehicle and rotates an axle 64. The vehicle on which the drive device 100 is mounted is a vehicle that uses a motor as a power source, such as a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHV), or an electric vehicle (EV). As shown in Figures 1 and 2, the drive device 100 includes a motor 20, a transmission mechanism 60, a housing 10 having a motor housing 11 that houses the motor 20 therein and a transmission mechanism housing 12 that houses the transmission mechanism 60 therein, bearings 71 to 76, an inverter unit 80, a rotation detection device 81, and a pump 94. The motor housing 11 and the transmission mechanism housing 12 are separate bodies that are fixed to each other. The transmission mechanism housing 12 is fixed to one axial side of the motor housing 11. In other words, the transmission mechanism housing 12 is connected to one axial side of the motor housing 11. The bearings 71 to 76 are, for example, ball bearings.

The motor 20 is a part that drives the drive unit 100. The motor 20 has a rotor 30 that can rotate around a central axis J1 that extends in the axial direction, and a stator 40 that covers the radial outside of the rotor 30. The rotor 30 has a motor shaft 31 and a rotor body 32. The motor shaft 31 can rotate around the central axis J1. The motor shaft 31 is rotatably supported by bearings 71 and 72. As a result, the bearings 71 and 72 rotatably support the rotor 30. In this embodiment, the bearing 72 corresponds to the "first bearing."

In this embodiment, the motor shaft 31 is a hollow shaft that opens on both axial sides. The motor shaft 31 is cylindrical and extends in the axial direction around the central axis J1. The entire motor shaft 31 is accommodated inside the motor housing 11. The motor shaft 31 is provided with a hole 33 that connects the inside of the motor shaft 31 to the outside of the motor shaft 31. One axial end of the motor shaft 31 is supported by a bearing 72. A first gear shaft 63 of the reduction gear 61, which will be described later, is connected to one axial end of the motor shaft 31. The rotor body 32 is fixed to the outer circumferential surface of the motor shaft 31. Although not shown, the rotor body 32 has a rotor core and a rotor magnet fixed to the rotor core.

The stator 40 is located radially outside the rotor 30. The stator 40 is fixed inside the motor housing 11. The stator 40 has a stator core 41 and a coil assembly 42. The stator core 41 is annular and surrounds the rotor 30. The coil assembly 42 has a plurality of coils 42c attached to the stator core 41 along the circumferential direction. The plurality of coils 42c are attached to the stator core 41 via an insulator (not shown). Although not shown, the coil assembly 42 may have a bundling member that bundles the coils 42c, or may have a crossover wire that connects the coils 42c together. The coil assembly 42 has a coil end 42a that protrudes from the stator core 41 to one side in the axial direction, and a coil end 42b that protrudes from the stator core 41 to the other side in the axial direction.

The transmission mechanism 60 is connected to the motor 20. The transmission mechanism 60 transmits the rotation of the rotor 30 to the axle 64 of the vehicle. As shown in FIG. 1, the transmission mechanism 60 of this embodiment has a reduction gear 61 connected to the motor 20 and a differential gear 62 connected to the reduction gear 61.

The reduction gear 61 has a first gear shaft 63, a first gear 61a, a second gear 61b, a third gear 61c, and a second gear shaft 61d. The first gear shaft 63 is a gear shaft axially connected to the motor shaft 31. That is, in this embodiment, the transmission mechanism 60 has the first gear shaft 63 as a gear shaft axially connected to the motor shaft 31. In this embodiment, the first gear shaft 63 is a hollow shaft that opens on both axial sides. The first gear shaft 63 is cylindrical and extends axially around the central axis J1. The outer diameter of the first gear shaft 63 is smaller than the outer diameter of the motor shaft 31.

The first gear shaft 63 is connected to one axial side of the motor shaft 31. The other axial end of the first gear shaft 63 is fitted into the inside of the one axial end of the motor shaft 31. The first gear shaft 63 extends from the inside of the motor housing 11 to the inside of the transmission mechanism housing 12. The motor shaft 31 and the first gear shaft 63 are connected to each other by spline fitting. The first gear shaft 63 is rotatably supported by bearings 73 and 74. In this embodiment, the bearing 73 corresponds to the "second bearing".

The first gear 61a is fixed to a portion of the first gear shaft 63 that is located inside the transmission mechanism housing 12. The second gear 61b and the third gear 61c are fixed to the second gear shaft 61d. The second gear 61b meshes with the first gear 61a. The second gear shaft 61d extends in the axial direction about a gear axis J2 that extends parallel to the central axis J1. The gear axis J2 is a virtual axis that is located below the central axis J1. The gear axis J2 is located, for example, rearward (-X side) of the central axis J1. The second gear shaft 61d is rotatably supported by bearings 75 and 76.

The differential device 62 has a ring gear 62a. The ring gear 62a meshes with the third gear 61c. The lower end of the ring gear 62a is immersed in the oil O stored in the transmission mechanism housing 12. As the ring gear 62a rotates, the oil O is scooped up. The scooped up oil O is supplied to the reduction gear 61 and the differential device 62, for example, as lubricating oil. The differential device 62 rotates the axle 64 around the differential axis J3. The differential axis J3 is an imaginary axis that extends parallel to the central axis J1.

The motor housing 11 houses the rotor 30 and the stator 40 inside. The motor housing 11 has a first housing member 13 and a second housing member 14.

The first housing member 13 is a cylindrical member that surrounds the motor 20 on the radial outside of the motor 20. In this embodiment, the inner peripheral surface of the first housing member 13 is cylindrical with the central axis J1 as the center. The first housing member 13 opens to the other axial side. The first housing member 13 is fixed to the transmission mechanism housing 12. The stator core 41 is fitted inside the first housing member 13. The first housing member 13 has a first opposing wall portion 13a that expands in the radial direction, a peripheral wall portion 13b that extends from the radial outer peripheral edge portion of the first opposing wall portion 13a to the other axial side, and a first bearing retaining portion 13c provided on the first opposing wall portion 13a.

The first opposing wall portion 13a faces the transmission mechanism housing 12 in the axial direction. The first opposing wall portion 13a is located on the other axial side of the transmission mechanism housing 12. The first opposing wall portion 13a is fixed to the transmission mechanism housing 12. More specifically, the first opposing wall portion 13a faces a third housing member 15 (described later) of the transmission mechanism housing 12 in the axial direction and is fixed to the other axial side of the third housing member 15. The first opposing wall portion 13a has a hole 13d that penetrates the first opposing wall portion 13a in the axial direction. The hole 13d is a circular hole centered on the central axis J1. The first gear shaft 63 passes through the hole 13d in the axial direction.

As shown in FIG. 2, the first opposing wall portion 13a has a first opening 13e that opens to the inside of the motor housing 11 and the outside of the motor housing 11. The first opening 13e penetrates the first opposing wall portion 13a in the axial direction. The first opening 13e is a through hole that connects the space S located axially between the first opposing wall portion 13a and a second opposing wall portion 15a (described later) to the inside of the motor housing 11. The first opening 13e is provided in a portion of the first opposing wall portion 13a that is located lower than the first bearing retaining portion 13c. The lower end of the first opening 13e is connected to the inner circumferential surface of the peripheral wall portion 13b.

As shown in FIG. 3, the first opening 13e is generally trapezoidal with rounded corners. The circumferential dimension of the first opening 13e increases radially outward. When viewed in the axial direction, the circumferential width of the first opening 13e that intersects with the vertical direction is wider on the lower vertical side. In this embodiment, the circumferential center of the first opening 13e is shifted toward the other circumferential side (-θ side) from the position directly below the central axis J1.

In this embodiment, the first bearing retaining portion 13c is provided on the other axial side of the first opposing wall portion 13a. The first bearing retaining portion 13c protrudes from the surface on the other axial side of the first opposing wall portion 13a to the other axial side. As shown in FIG. 3, the first bearing retaining portion 13c is cylindrical with the center on the central axis J1. The first bearing retaining portion 13c has a through portion 13f that penetrates the first bearing retaining portion 13c in the radial direction. In this embodiment, the through portion 13f penetrates a portion of the first bearing retaining portion 13c that is above the central axis J1 and located on the rear side (-X side) in the radial direction. The through portion 13f extends from the inner peripheral surface of the first bearing retaining portion 13c to the outer peripheral surface of the first bearing retaining portion 13c, rearward and obliquely upward. As shown in FIG. 1, the first bearing retaining portion 13c holds the bearing 72 inside.

The second housing member 14 is separate from the first housing member 13. The second housing member 14 is fixed to the other axial side of the first housing member 13. The second housing member 14 closes the opening on the other axial side of the first housing member 13. As shown in FIG. 4, the second housing member 14 has a cover wall portion 14a that extends in the radial direction and a peripheral wall portion 14b that extends from the radial outer peripheral edge of the cover wall portion 14a to one axial side. As shown in FIG. 1, the end of the peripheral wall portion 14b on one axial side is in contact with the end of the peripheral wall portion 13b on the other axial side of the first housing member 13. The cover wall portion 14a has a recess 14c that is recessed from the surface on one axial side of the cover wall portion 14a to the other axial side. The portion on one axial side of the recess 14c is a bearing holding portion 14d that holds the bearing 71 inside.

A holding portion 14f protruding to one axial side is provided on the surface on one axial side of the cover wall portion 14a. The holding portion 14f surrounds the opening of the recess 14c on the surface on one axial side of the cover wall portion 14a. A rotation detection device 81 is held on the radial inside of the holding portion 14f. The rotation detection device 81 is capable of detecting the rotation of the rotor 30. In this embodiment, the rotation detection device 81 has a detected portion 81a fixed to the motor shaft 31 and a detecting portion 81b fixed to the second housing member 14. The detected portion 81a is annular and surrounds the motor shaft 31. The detecting portion 81b is held on the radial inside of the holding portion 14f. The detecting portion 81b is annular and surrounds the detected portion 81a.

In this embodiment, the rotation detection device 81 is a resolver. The detected part 81a is a resolver rotor. The detection part 81b is a resolver stator. When the detected part 81a rotates together with the motor shaft 31, an induced voltage corresponding to the circumferential position of the detected part 81a is generated in the coil of the detection part 81b. The rotation detection device 81 can detect the rotation of the detected part 81a and the motor shaft 31 based on the change in the induced voltage generated in the coil of the detection part 81b. This allows the rotation detection device 81 to detect the rotation of the rotor 30. In this embodiment, since the detection part 81b is fixed to the second housing member 14 that is separate from the first housing member 13, an assembly method can be adopted in which the detection part 81b is fixed to the second housing member 14 and then the second housing member 14 is fixed to the first housing member 13. Therefore, the rotation detection device 81 can be easily installed.

In this embodiment, an inverter unit 80 is attached to the motor housing 11. The inverter unit 80 is fixed to the rear surface of the motor housing 11. Although not shown, the inverter unit 80 has an inverter circuit electrically connected to the stator 40.

The transmission mechanism housing 12 accommodates the reduction gear 61 and the differential gear 62 inside. As shown in FIG. 2, the transmission mechanism housing 12 protrudes downward from the motor housing 11. The bottom surface located on the lower side of the inner surface of the transmission mechanism housing 12 is located lower than the bottom surface located on the lower side of the inner surface of the motor housing 11. The transmission mechanism housing 12 has a third housing member 15 fixed to the first housing member 13, and a fourth housing member 16 fixed to one axial side of the third housing member 15.

As shown in FIG. 1, the third housing member 15 has a second opposing wall portion 15a that extends in the radial direction, a peripheral wall portion 15b that extends from the radial outer peripheral edge portion of the second opposing wall portion 15a to one axial side, a second bearing holder portion 15c provided on the second opposing wall portion 15a, and a bearing holder portion 15d provided on the second opposing wall portion 15a. The second opposing wall portion 15a faces the first opposing wall portion 13a in the axial direction. The second opposing wall portion 15a is fixed to one axial side of the first opposing wall portion 13a. The second opposing wall portion 15a has a hole 15f that penetrates the second opposing wall portion 15a in the axial direction. The hole 15f is a circular hole centered on the central axis J1. The first gear shaft 63 is passed through the hole 15f in the axial direction.

The second opposing wall portion 15a has a recess 15e recessed from the surface on the other axial side of the second opposing wall portion 15a toward one axial side. The inner peripheral edge of the recess 15e is, for example, circular about the central axis J1 when viewed in the axial direction. The opening on the other axial side of the recess 15e is blocked by the first opposing wall portion 13a. A space S is provided between the first opposing wall portion 13a and the second opposing wall portion 15a in the axial direction. The space S is formed by the inside of the recess 15e.

As shown in FIG. 2, the second opposing wall portion 15a has a second opening 15h that opens to the inside of the transmission mechanism housing 12 and the outside of the transmission mechanism housing 12. The second opening 15h penetrates the second opposing wall portion 15a in the axial direction. The second opening 15h is a through hole that connects the space S located between the first opposing wall portion 13a and the second opposing wall portion 15a in the axial direction and the inside of the transmission mechanism housing 12. The second opening 15h is provided in a portion of the second opposing wall portion 15a that is located lower than the second bearing retaining portion 15c. The second opening 15h is provided at the lower end of the bottom surface of the recess 15e. The bottom surface of the recess 15e is a surface that is located on one axial side of the inner surface of the recess 15e and faces the other axial side. The lower end of the second opening 15h is connected to the inner circumferential surface of the recess 15e. More specifically, as shown in FIG. 5, the lower end of the second opening 15h is connected to the bottom surface of a recess 15u provided in the lower side surface 15t located on the lower side of the inner circumferential surface of the recess 15e. The recess 15u is provided on one axial side of the lower side surface 15t. The recess 15u is recessed downward and opens to the upper side and one axial side. The inside of the recess 15u is connected to the inside of the lower part of the second opening 15h. The inside of the recess 15u opens to the inside of the transmission mechanism housing 12 via the second opening 15h.

The second opening 15h is disposed opposite to one axial side of the first opening 13e provided in the first opposing wall portion 13a with a gap therebetween. As shown in FIG. 6, the first opening 13e and the second opening 15h at least partially overlap each other when viewed in the axial direction. In this embodiment, the first opening 13e and the second opening 15h overlap each other by more than half when viewed in the axial direction. The second opening 15h protrudes downward from the first opening 13e. The front end (+X side) of the first opening 13e protrudes forward from the second opening 15h.

The second opening 15h is a generally elliptical shape with a circumferential dimension larger than a radial dimension. The circumferential dimension of the lower part of the second opening 15h is larger than the circumferential dimension of the upper part of the second opening 15h. In other words, when viewed in the axial direction, the circumferential width of the second opening 15h intersecting with the vertical direction is wider on the lower side in the vertical direction. In this embodiment, the circumferential center of the second opening 15h is shifted toward the other circumferential side (-θ side) from the position directly below the central axis J1. As shown in Figures 5 and 6, the opening area of the opening end 15w of the second opening 15h that opens into the inside of the transmission mechanism housing 12 is larger than the opening area of the opening end 13w of the first opening 13e that opens into the inside of the motor housing 11.

As shown in FIG. 2, in this embodiment, the first opposing wall portion 13a and the second opposing wall portion 15a form a partition portion 19 that separates the interior of the motor housing 11 from the interior of the transmission mechanism housing 12. In other words, the housing 10 has the partition portion 19. The partition portion 19 has a through hole 19a that connects the interior of the motor housing 11 to the interior of the transmission mechanism housing 12. The through hole 19a penetrates the partition portion 19 in the axial direction. In this embodiment, the through hole 19a is formed by the first opening 13e and the lower end of the recess 15e provided in the first opposing wall portion 13a, and the second opening 15h provided in the second opposing wall portion 15a.

As shown in FIG. 1, in this embodiment, the second bearing retaining portion 15c and the bearing retaining portion 15d are provided on one axial side of the second opposing wall portion 15a. The second bearing retaining portion 15c and the bearing retaining portion 15d protrude from one axial side of the surface of the second opposing wall portion 15a. As shown in FIG. 7, the second bearing retaining portion 15c is cylindrical and centered on the central axis J1. The bearing retaining portion 15d is cylindrical and centered on the gear axis J2. As shown in FIG. 1, the second bearing retaining portion 15c retains the bearing 73 therein. The bearing retaining portion 15d retains the bearing 75 therein.

The fourth housing member 16 has a cover wall portion 16a that extends in the radial direction, a peripheral wall portion 16b that extends from the radial outer peripheral edge of the cover wall portion 16a to the other axial direction side, and bearing retaining portions 16c and 16d provided on the cover wall portion 16a. The other axial end of the peripheral wall portion 16b is in axial contact with the one axial end of the peripheral wall portion 15b of the third housing member 15.

In this embodiment, the bearing holders 16c and 16d are provided on the surface of the other axial side of the cover wall portion 16a. The bearing holders 16c and 16d protrude from the surface of the other axial side of the cover wall portion 16a toward the other axial side. Although not shown, the bearing holder 16c is cylindrical and centered on the central axis J1. The bearing holder 16d is cylindrical and centered on the gear axis J2. The bearing holder 16c holds the bearing 74 therein. The bearing holder 16d holds the bearing 76 therein.

As shown in FIG. 2, oil O is contained inside the transmission mechanism housing 12. The oil O is stored in a lower region inside the transmission mechanism housing 12. The oil O is used as a refrigerant that cools the motor 20. The oil O is also used as a lubricant for the reduction gear 61 and the differential gear 62. As the oil O, for example, it is preferable to use an oil equivalent to an automatic transmission lubricant (ATF: Automatic Transmission Fluid) that has a relatively low viscosity in order to perform the functions of a refrigerant and a lubricant. In this embodiment, the oil O corresponds to the first fluid.

In this embodiment, a pump 94 is attached to the transmission mechanism housing 12. The pump 94 is attached to the lower surface of the transmission mechanism housing 12. The pump 94 is a pump that flows oil O into the second supply flow path 92, which will be described later. In this embodiment, the pump 94 is an electric pump. Note that the pump 94 may be a mechanical pump that is rotated by the first gear shaft 63 or the second gear shaft 61d.

Although not shown in the figure, the axial gap between the first housing member 13 and the second housing member 14, the axial gap between the first housing member 13 and the third housing member 15, and the axial gap between the third housing member 15 and the fourth housing member 16 are sealed by sealing members. The sealing member is, for example, a liquid gasket.

In this embodiment, the first housing member 13, the second housing member 14, the third housing member 15, and the fourth housing member 16 are fixed to each other by bolts. More specifically, as shown in FIG. 8, the first housing member 13 and the second housing member 14 are fixed to each other by a first bolt 10a. The first housing member 13 and the third housing member 15 are fixed to each other by a second bolt 10b. The third housing member 15 and the fourth housing member 16 are fixed to each other by a third bolt 10c. The first bolt 10a, the second bolt 10b, and the third bolt 10c are each provided in a plurality of bolts surrounding the central axis J1. That is, the second housing member 14 is fixed to the other axial side of the first housing member 13 by a plurality of first bolts 10a. The third housing member 15 is fixed to one axial side of the first housing member 13 by a plurality of second bolts 10b. The fourth housing member 16 is fixed to one axial side of the third housing member 15 by multiple third bolts 10c.

The first bolts 10a respectively fix the first protrusions 13k provided on the outer peripheral surface of the first housing member 13 and the second protrusions 14k provided on the outer peripheral surface of the second housing member 14. The first protrusions 13k are provided on the other axial end of the outer peripheral surface of the first housing member 13. The first protrusions 13k protrude radially outward. As shown in Figs. 9 and 10, the first protrusions 13k are spaced apart along the circumferential direction. As shown in Fig. 10, in this embodiment, the first protrusions 13k are equally spaced around the circumference. In this embodiment, eight first protrusions 13k are provided.

In this specification, "certain objects are arranged at equal intervals" includes cases where certain objects are arranged at strictly equal intervals, and cases where certain objects are arranged at approximately equal intervals.

The first protrusion 13k has a female screw hole 13p recessed from the surface on the other axial side of the first protrusion 13k to one axial side. In this embodiment, the female screw hole 13p penetrates the first protrusion 13k in the axial direction. Note that the female screw hole 13p may be a hole having a bottom on one axial side. One female screw hole 13p is provided for each first protrusion 13k. In other words, in this embodiment, a total of eight female screw holes 13p are provided. In this embodiment, the multiple female screw holes 13p are arranged at equal intervals around the circumference.

As shown in FIG. 9, the second protrusion 14k is provided at one axial end of the outer peripheral surface of the second housing member 14. The second protrusion 14k protrudes radially outward. The second protrusions 14k are arranged at intervals along the circumferential direction. Although not shown, the second protrusions 14k are arranged at equal intervals around the circumference. For example, eight second protrusions 14k are provided. The surface on one axial side of each second protrusion 14k is in contact with the surface on the other axial side of each first protrusion 13k.

The second protrusion 14k has a fixing hole 14p penetrating the second protrusion 14k in the axial direction. One fixing hole 14p is provided for each second protrusion 14k. For example, a total of eight fixing holes 14p are provided. The multiple fixing holes 14p are arranged, for example, at equal intervals around one circumference along the circumferential direction. When viewed in the axial direction, each fixing hole 14p and each female screw hole 13p overlap each other. Each first bolt 10a is passed through each fixing hole 14p from the other axial side and screwed into each female screw hole 13p. In this way, the first housing member 13 and the second housing member 14 are fixed by the multiple first bolts 10a. As shown in FIG. 10, the multiple first bolts 10a are arranged at equal intervals around one circumference along the circumferential direction around the central axis J1.

8 and 9, the second bolts 10b respectively fix the third protrusions 13m provided on the outer peripheral surface of the first housing member 13 and the fourth protrusions 15m provided on the outer peripheral surface of the third housing member 15. The third protrusions 13m are provided at one axial end of the outer peripheral surface of the first housing member 13. The third protrusions 13m protrude radially outward. The third protrusions 13m are arranged at intervals along the circumferential direction. As shown in FIG. 10, in this embodiment, the third protrusions 13m are arranged at equal intervals around the circumference along the circumferential direction. In this embodiment, eight third protrusions 13m are provided. The circumferential position of the third protrusions 13m is shifted with respect to the circumferential position of the first protrusions 13k. The circumferential position of the third protrusions 13m is, for example, the central position in the circumferential direction between the first protrusions 13k adjacent to each other in the circumferential direction. In this embodiment, the multiple first protrusions 13k and the multiple third protrusions 13m are arranged alternately with each other along the circumferential direction when viewed in the axial direction.

The third protrusion 13m has a fixing hole 13q that penetrates the third protrusion 13m in the axial direction. One fixing hole 13q is provided for each third protrusion 13m. In other words, in this embodiment, a total of eight fixing holes 13q are provided. The multiple fixing holes 13q are arranged at equal intervals around the circumference.

As shown in Figures 8 and 9, the fourth protrusion 15m is provided on the other axial end of the outer peripheral surface of the third housing member 15. The fourth protrusion 15m protrudes radially outward. The multiple fourth protrusions 15m are arranged at intervals along the circumferential direction. Although not shown, the multiple fourth protrusions 15m are arranged at equal intervals around the circumference. For example, eight fourth protrusions 15m are provided. The surface on the other axial side of each fourth protrusion 15m is in contact with the surface on one axial side of each third protrusion 13m.

The fourth protrusion 15m has a female screw hole 15q recessed from the surface on the other axial side of the fourth protrusion 15m to one axial side. In this embodiment, the female screw hole 15q penetrates the fourth protrusion 15m in the axial direction. Note that the female screw hole 15q may be a hole having a bottom on one axial side. One female screw hole 15q is provided for each fourth protrusion 15m. For example, a total of eight female screw holes 15q are provided. The multiple female screw holes 15q are, for example, arranged at equal intervals around one circumference in the circumferential direction.

When viewed in the axial direction, each fixing hole 13q and each female screw hole 15q overlap with each other. Each second bolt 10b is passed through each fixing hole 13q from the other axial side and screwed into each female screw hole 15q. In this way, the first housing member 13 and the third housing member 15 are fixed by the multiple second bolts 10b. As shown in FIG. 10, the multiple second bolts 10b are arranged at equal intervals around one circumference along the circumferential direction around the central axis J1. In this embodiment, the multiple first bolts 10a and the multiple second bolts 10b are arranged alternately with each other along the circumferential direction around the central axis J1 when viewed in the axial direction. When viewed in the axial direction, each second bolt 10b is located at the center in the circumferential direction between the first bolts 10a adjacent in the circumferential direction.

In this manner, in this embodiment, the first housing member 13 and the third housing member 15 are fixed to each other by the second bolt 10b, which is fastened from the same side as the first bolt 10a that fixes the first housing member 13 and the second housing member 14. In other words, the second bolt 10b that fixes the first housing member 13 and the third housing member 15 is inserted into the fixing hole 13q and the female screw hole 15q in the same orientation as the first bolt 10a that fixes the first housing member 13 and the second housing member 14.

As shown in FIG. 8, the third bolt 10c fixes the fifth protrusion 15n provided at one axial end of the outer peripheral surface of the third housing member 15 and the sixth protrusion 16n provided at the other axial end of the outer peripheral surface of the fourth housing member 16. Although not shown, the fifth protrusion 15n and the sixth protrusion 16n are provided in multiples at intervals in the circumferential direction. The fifth protrusion 15n and the sixth protrusion 16n protrude radially outward. The circumferential positions of the fifth protrusion 15n and the sixth protrusion 16n may be the same as the circumferential positions of the third protrusion 13m and the fourth protrusion 15m, or may be shifted in the circumferential direction relative to the third protrusion 13m and the fourth protrusion 15m.

The fifth protrusion 15n has a female screw hole 15r recessed from one axial side of the fifth protrusion 15n to the other axial side. In this embodiment, the female screw hole 15r penetrates the fifth protrusion 15n in the axial direction. The female screw hole 15r may be a hole having a bottom on the other axial side. The sixth protrusion 16n has a fixing hole 16r penetrating the sixth protrusion 16n in the axial direction. Each third bolt 10c is passed through each fixing hole 16r from one axial side and tightened into each female screw hole 15r. In this way, the third housing member 15 and the fourth housing member 16 are fixed by a plurality of third bolts 10c.

In this embodiment, the third housing member 15 and the fourth housing member 16 are fixed to each other by the first bolt 10a that fixes the first housing member 13 and the second housing member 14 and the third bolt 10c that is fastened from the side opposite to the side where the second bolt 10b that fixes the first housing member 13 and the third housing member 15 is fastened. In other words, the third bolt 10c that fixes the third housing member 15 and the fourth housing member 16 is inserted into the fixing hole 16r and the female screw hole 15r in a different direction from the first bolt 10a that fixes the first housing member 13 and the second housing member 14 and the second bolt 10b that fixes the first housing member 13 and the third housing member 15.

In this embodiment, the female screw holes 13p, 15q, and 15r correspond to "bolt holes." In this embodiment, the fixing holes 13q, 14p, and 16r correspond to "through holes."

As described above, in this embodiment, the first bolts 10a that fix the first housing member 13 and the second housing member 14 are passed through the fixing holes 14p as a plurality of through holes provided in the second housing member 14 from the other axial side, and are fixed to the female threaded holes 13p as a plurality of bolt holes provided in the first housing member 13. The second bolts 10b that fix the first housing member 13 and the third housing member 15 are passed through the fixing holes 13q as a plurality of through holes provided in the first housing member 13 from the other axial side, and are fixed to the female threaded holes 15q as a plurality of bolt holes provided in the third housing member 15. The third bolts 10c that fix the third housing member 15 and the fourth housing member 16 are passed through the fixing holes 16r as a plurality of through holes provided in the fourth housing member 16 from one axial side, and are fixed to the female threaded holes 15r as a plurality of bolt holes provided in the third housing member 15. In other words, the first housing member 13 and the third housing member 15 are fixed by the second bolt 10b from the same axial side as the side on which the first housing member 13 and the second housing member 14 are fixed by the first bolt 10a. Therefore, the work of fixing the first housing member 13 and the second housing member 14 and the work of fixing the first housing member 13 and the third housing member 15 can be performed from the same axial side, that is, from the other axial side in this embodiment. This improves the ease of assembly of the housing 10.

In this embodiment, the transmission mechanism housing 12 has a shape that protrudes radially outward beyond the motor housing 11. In such a case, if an attempt is made to fasten the first housing member 13 and the third housing member 15 by inserting a bolt from the side where the transmission mechanism housing 12 is located relative to the motor housing 11, i.e., from one axial side, it becomes necessary to position the fastening portion of the bolt further radially outward to avoid interference with the transmission mechanism housing 12 itself. This makes it easy for the housing 10 to become large.

In response to this, for example, if the first housing member 13, the third housing member 15, and the fourth housing member 16 are fastened together with a bolt inserted from one axial side, the first housing member 13 and the third housing member 15 can be fixed while preventing the housing 10 from becoming large. However, in this case, when the bolt is removed to separate the motor housing 11 and the transmission mechanism housing 12, the third housing member 15 and the fourth housing member 16 constituting the transmission mechanism housing 12 are also separated. Therefore, when not fixed to the motor housing 11, the transmission mechanism housing 12 cannot be handled in an assembled state. This tends to make the housing 10 difficult to assemble. In addition, workability tends to be poor when performing maintenance on the drive unit 100 and when replacing the transmission mechanism 60.

In addition, the axial force of the bolt required to maintain a suitable seal may differ between the seal member provided axially between the first housing member 13 and the third housing member 15 and the seal member provided axially between the third housing member 15 and the fourth housing member 16. Therefore, if the first housing member 13, the third housing member 15, and the fourth housing member 16 are fastened together with the same bolt, it may be difficult to apply a suitable axial force to the seal members respectively arranged between each housing member. This can easily cause problems such as a decrease in the seal between each housing member and difficulty in adjusting the axial force of the bolt.

The problems that arise when the first housing member 13, the third housing member 15, and the fourth housing member 16 are fastened together with a bolt inserted from one axial side as described above are also the same when the first housing member 13, the second housing member 14, and the third housing member 15 are fastened together with a bolt inserted from the other axial side.

In response to the above problem, according to this embodiment, as described above, the first housing member 13 and the third housing member 15 are fixed by the second bolt 10b from the same side in the axial direction as the side on which the first housing member 13 and the second housing member 14 are fixed by the first bolt 10a. Therefore, even if the position of the part fixed by the second bolt 10b is not changed to a more radially outer position, it is possible to prevent the second bolt 10b from interfering with the transmission mechanism housing 12. This allows the first housing member 13 and the third housing member 15 to be fixed by the second bolt 10b while preventing the housing 10 from becoming larger. Furthermore, even if the second bolt 10b is removed, only the first housing member 13 and the third housing member 15 are separated, and the third housing member 15 and the fourth housing member 16 are not separated. Therefore, even if the transmission mechanism housing 12 is not fixed to the motor housing 11, it can be handled in an assembled state. This prevents the housing 10 from becoming difficult to assemble. In addition, it is possible to prevent deterioration of workability when performing maintenance on the drive unit 100 and when replacing the transmission mechanism 60. In addition, since the axial force can be changed for each of the second bolt 10b and the third bolt 10c, different axial forces can be applied individually to the seal member located between the first housing member 13 and the third housing member 15 and the seal member located between the third housing member 15 and the fourth housing member 16. This makes it easy to ensure the sealability between the housing members, and also makes it easy to adjust the axial force of the second bolt 10b and the axial force of the third bolt 10c. The same applies to the seal member between the first housing member 13 and the second housing member 14.

For example, if another housing member is disposed between the motor housing 11 and the transmission mechanism housing 12 and the motor housing 11 and the transmission mechanism housing 12 are fixed to the other housing member, the motor housing 11 and the transmission mechanism housing 12 can be separated from each other in an assembled state. However, in this case, the number of parts constituting the housing 10 increases by the amount of the other housing member. In contrast, according to the present embodiment, as described above, the motor housing 11 and the transmission mechanism housing 12 can be separated from each other in an assembled state without providing the other member. Therefore, the increase in the number of parts constituting the housing 10 can be suppressed. In addition, since the other member is not required, the weight of the drive unit 100 can be reduced. As a result, even if the structure of the drive unit 100 is a water-cooled structure in which the motor 20 is cooled by water W as in the present embodiment, the increase in the weight of the entire drive unit 100 can be suppressed.

In addition, according to this embodiment, the first bolts 10a that secure the first housing member 13 and the second housing member 14 secure the first protrusions 13k provided on the outer peripheral surface of the first housing member 13 and the second protrusions 14k provided on the outer peripheral surface of the second housing member 14. In this way, by providing the first protrusions 13k and the second protrusions 14k that partially protrude from the outer peripheral surface of each housing member and securing the first protrusions 13k and the second protrusions 14k with the first bolts 10a, it is possible to prevent the first housing member 13 and the second housing member 14 from becoming large in the radial direction around the entire circumference.

In addition, according to this embodiment, the multiple second bolts 10b that secure the first housing member 13 and the third housing member 15 secure the multiple third protrusions 13m provided on the outer peripheral surface of the first housing member 13 and the multiple fourth protrusions 15m provided on the outer peripheral surface of the third housing member 15. In this way, by providing the third protrusions 13m and the fourth protrusions 15m that partially protrude from the outer peripheral surface of each housing member and securing the third protrusions 13m and the fourth protrusions 15m with the second bolts 10b, it is possible to prevent the first housing member 13 and the third housing member 15 from becoming larger in the radial direction around the entire circumference.

In addition, according to this embodiment, the multiple first bolts 10a and the multiple second bolts 10b are arranged alternately with each other along the circumferential direction around the central axis J1 when viewed in the axial direction. Therefore, the multiple first bolts 10a and the multiple second bolts 10b are arranged along the circumferential direction, respectively, to stably fix the first housing member 13, the second housing member 14, and the third housing member 15, while preventing one of the first bolts 10a and the second bolts 10b from interfering with the other. This makes it easier to perform the work of fixing the first housing member 13 and the second housing member 14 with the first bolt 10a and the work of fixing the first housing member 13 and the third housing member 15 with the second bolt 10b when they are performed from the same axial side. Therefore, the assemblability of the housing 10 can be improved.

In addition, according to this embodiment, the multiple first bolts 10a are arranged at equal intervals around the circumference of the center axis J1. Therefore, the multiple first bolts 10a can more stably fix the first housing member 13 and the second housing member 14. In addition, the axial force applied by the multiple first bolts 10a to the seal member located between the first housing member 13 and the second housing member 14 can be made uniform over the entire circumference. This makes it easier to appropriately seal between the first housing member 13 and the second housing member 14 over the entire circumference.

In addition, according to this embodiment, the multiple second bolts 10b are arranged at equal intervals around the circumference of the center axis J1. Therefore, the first housing member 13 and the third housing member 15 can be fixed more stably by the multiple second bolts 10b. In addition, the axial force applied by the multiple second bolts 10b to the seal member located between the first housing member 13 and the third housing member 15 can be made uniform over the entire circumference. This makes it easier to appropriately seal the gap between the first housing member 13 and the third housing member 15 over the entire circumference.

As shown by the two-dot chain line in FIG. 9, the third protrusion 13m provided on the first housing member 13 may extend in the axial direction. In this case, the end of the third protrusion 13m on the other axial side can be brought closer to the first protrusion 13k. As a result, when the work of fixing the first housing member 13 and the third housing member 15 is performed from the other axial side, the position where the jig and tool for tightening the second bolt 10b are used can be brought closer to the position where the jig and tool are used when the work of fixing the first housing member 13 and the second housing member 14 is performed. In addition, the axial dimension of the jig and tool can be shortened. As a result, the workability of the work of fixing the first housing member 13 and the third housing member 15 with the second bolt 10b can be improved. In particular, the second bolt 10b can be tightened appropriately to generate an axial force appropriately.

The end portion on the other axial direction of the third protrusion 13m shown by a two-dot chain line in FIG. 9 is, for example, located on the other axial direction side of the axial center of the first housing member 13. The end portion on the other axial direction of the third protrusion 13m shown by a two-dot chain line in FIG. 9 is, for example, located on one axial direction side of the end portion on one axial direction side of the first protrusion 13k. This makes it possible to prevent the third protrusion 13m from interfering with the first protrusion 13k.

As shown in Figs. 3 and 4, in this embodiment, the first housing member 13 and the second housing member 14 are also fixed by a fourth bolt 10d that is different from the multiple first bolts 10a described above. As shown in Fig. 3, the first housing member 13 has a female threaded hole 13i that is recessed axially from the end face on the other axial side of the peripheral wall portion 13b to one side. The female threaded hole 13i is located circumferentially between a groove portion 93a described later and a second circumferential flow path portion 52b of the second flow path 50 described later. The female threaded hole 13i is located radially inside a second recovery path main body portion 93c described later. The female threaded hole 13i is a bolt hole into which the fourth bolt 10d is tightened to fix the first housing member 13.

As shown in FIG. 4, the second housing member 14 has a fixing hole 14e as a through hole that penetrates the second housing member 14 in the axial direction. The fixing hole 14e is located circumferentially between a connection portion 93b described later and a second circumferential flow path portion 52b of the second flow path 50 described later. The fixing hole 14e is located radially inside a second recovery path main body portion 93c described later. A fourth bolt 10d passed through the fixing hole 14e from the other axial side is fastened to the female thread hole 13i. As a result, in this embodiment, the first housing member 13 and the second housing member 14 are fixed to each other radially inside the recovery flow path 93 described later and at a position adjacent to the second flow path 50 in the circumferential direction.

As shown in FIG. 11, the first housing member 13 has a positioning protrusion 13r provided on the outer circumferential surface of the first housing member 13. The second housing member 14 has a positioning protrusion 14r provided on the outer circumferential surface of the second housing member 14. The positioning protrusions 13r, 14r protrude radially outward. The positioning protrusion 13r has a hole 13s recessed from the surface on the other axial side of the positioning protrusion 13r to one axial side. The hole 13s is a circular hole with a bottom on one axial side. The positioning protrusion 14r has a hole 14s recessed from the surface on the one axial side of the positioning protrusion 14r to the other axial side. The hole 14s is a circular hole with a bottom on the other axial side. The hole 13s and the hole 14s face each other in the axial direction.

The positioning protrusion 13r is connected to one first protrusion 13k in the circumferential direction. The positioning protrusion 14r is connected to one second protrusion 14k in the circumferential direction. The positioning protrusion 13r and the positioning protrusion 14r are in contact with each other in the axial direction. As shown in FIG. 10, in this embodiment, two positioning protrusions 13r are provided with a gap therebetween in the circumferential direction. The two positioning protrusions 13r are provided at positions almost opposite each other across the central axis J1 in the radial direction. Although not shown in the figure, two positioning protrusions 14r are also provided with a gap therebetween in the circumferential direction, similar to the positioning protrusions 13r.

As shown in FIG. 11, in this embodiment, the housing 10 has a positioning pin 10e that positions the first housing member 13 and the second housing member 14 in the circumferential direction. The positioning pin 10e is cylindrical and extends in the axial direction. The positioning pin 10e is fitted into both a hole 13s provided in the positioning protrusion 13r of the first housing member 13 and a hole 14s provided in the positioning protrusion 14r of the second housing member 14. This positions the first housing member 13 and the second housing member 14 in the circumferential direction.

A portion of the positioning pin 10e on one axial side is fitted into the hole 13s. A portion of the positioning pin 10e on the other axial side is fitted into the hole 14s. As shown in FIG. 10, in this embodiment, two positioning pins 10e are provided. The two positioning pins 10e are provided at positions approximately opposite each other across the central axis J1.

In addition, in Figures 1 and 2, the first protrusion 13k, the second protrusion 14k, the third protrusion 13m, the fourth protrusion 15m, the fifth protrusion 15n, the sixth protrusion 16n, and the positioning protrusions 13r and 14r are omitted. In Figure 3, the first protrusion 13k and the positioning protrusion 13r are omitted. In Figure 4, the second protrusion 14k and the positioning protrusion 14r are omitted. In Figure 14, the first protrusion 13k, the second protrusion 14k, the third protrusion 13m, and the positioning protrusions 13r and 14r are omitted.

As shown in FIG. 2, the housing 10 has a first gutter portion 17. The first gutter portion 17 is located axially between the first opposing wall portion 13a and the second opposing wall portion 15a. In other words, the first gutter portion 17 is located in the space S. As shown in FIG. 12, the first gutter portion 17 is gutter-shaped and opens upward and extends in the axial direction. Oil O flows inside the first gutter portion 17. The first gutter portion 17 is a reservoir capable of storing oil O inside. In this embodiment, the first gutter portion 17 is located rearward (-X side) of the central axis J1. The first gutter portion 17 is located rearward of the hole 13d.

The first gutter 17 connects the first opposing wall 13a and the second opposing wall 15a. In this embodiment, the first gutter 17 has a first portion 17a that protrudes in one axial direction from the surface on one axial side (+Y side) of the first opposing wall 13a, and a second portion 17b that protrudes in the other axial direction from the surface on the other axial side (-Y side) of the second opposing wall 15a. The end of the first portion 17a on one axial side and the end of the second portion 17b on the other axial side are connected to each other. The axial dimension of the second portion 17b is larger than the axial dimension of the first portion 17a.

The first gutter portion 17 has a bottom surface 17c facing upward, and a pair of side surfaces 17d, 17e that protrude upward from both front-to-rear sides of the bottom surface 17c. The bottom surface 17c and the pair of side surfaces 17d, 17e extend in the axial direction. The bottom surface 17c and the pair of side surfaces 17d, 17e connect the first opposing wall portion 13a and the second opposing wall portion 15a. The pair of side surfaces 17d, 17e are arranged opposite each other with a gap in the axial direction. The side surface 17d is located in front of the side surface 17e (+X side).

The bottom surface 17c is inclined vertically with respect to the front-rear direction. The bottom surface 17c is located lower as it approaches the front side (+X side). In this embodiment, the bottom surface 17c is an inclined surface that is located lower as it approaches the first hole portion 13g provided in the first opposing wall portion 13a. Therefore, it is easy to guide the oil O in the first gutter portion 17 along the bottom surface 17c into the first hole portion 13g by utilizing gravity. The first hole portion 13g penetrates the first opposing wall portion 13a in the axial direction. The first hole portion 13g is, for example, a circular hole. The first hole portion 13g opens at the front end of the inside of the first gutter portion 17. The first hole portion 13g is connected to the bottom surface 17c and the side surface 17d.

As shown in FIG. 7, the first gutter 17 is connected to a portion of the surface of the first opposing wall 13a on one axial side that is located below the first hole 13g and a portion of the surface of the second opposing wall 15a on the other axial side that is located below the second hole 15g. The second hole 15g penetrates the second opposing wall 15a in the axial direction. The second hole 15g is, for example, a circular hole. The second hole 15g opens to the rear end (-X side) of the interior of the first gutter 17 and the front end (+X side) of the interior of the second gutter 18.

As shown in FIG. 2, the housing 10 has a second gutter portion 18. The second gutter portion 18 is located inside the transmission mechanism housing 12. As shown in FIG. 7 and FIG. 13, the second gutter portion 18 is gutter-shaped and opens upward and extends in the axial direction. Oil O flows inside the second gutter portion 18. The second gutter portion 18 is a reservoir capable of storing oil O inside. In this embodiment, the second gutter portion 18 is located rearward (-X side) of the central axis J1. The second gutter portion 18 is located above the bearing holding portion 15d. As shown in FIG. 7, the front (+X side) end of the second gutter portion 18 is located on one axial side (+Y side) of the rear end of the first gutter portion 17.

As shown in FIG. 2, the second gutter portion 18 connects the second opposing wall portion 15a and the cover wall portion 16a. In this embodiment, the second gutter portion 18 has a first portion 18a that protrudes to one axial direction side from a surface on one axial direction side (+Y side) of the second opposing wall portion 15a, and a second portion 18b that protrudes to the other axial direction side from a surface on the other axial direction side (-Y side) of the cover wall portion 16a. The end portion on one axial direction side of the first portion 18a and the end portion on the other axial direction side of the second portion 18b are connected to each other.

As shown in FIG. 13, the second gutter portion 18 has a bottom surface 18c facing upward, and a pair of side surfaces 18d, 18e that protrude upward from both front-to-rear sides of the bottom surface 18c. The bottom surface 18c and the pair of side surfaces 18d, 18e extend in the axial direction. The bottom surface 18c and the pair of side surfaces 18d, 18e connect the second opposing wall portion 15a and the cover wall portion 16a. The pair of side surfaces 18d, 18e are arranged opposite each other with a gap in the axial direction.

Side 18d is located in front of side 18e (+X side). Side 18d is inclined in the front-to-rear direction with respect to the vertical direction. Side 18d is located closer to the front (+X side) as it moves upward. In this embodiment, side 18d is an inclined surface that is located lower as it approaches second hole 15g. Therefore, oil O that has entered second gutter 18 can be easily guided along side 18d to inside second hole 15g by utilizing gravity.

The side surface 18e is inclined in the front-to-rear direction with respect to the vertical direction. The side surface 18d is located toward the rear (-X side) as it moves upward. The bottom surface 18c is inclined in the vertical direction with respect to the front-to-rear direction. The bottom surface 18c is located toward the rear (-X side).

As shown in FIG. 7, the second gutter portion 18 is connected to a portion of the surface on one axial side of the second opposing wall portion 15a that is located below the second hole portion 15g. The second gutter portion 18 is provided with supply holes 18f, 18g. The supply hole portion 18f connects the inside of the second gutter portion 18 to the inside of the second bearing holder portion 15c. Therefore, a portion of the oil O that enters the second gutter portion 18 is supplied to the bearing 73 in the second bearing holder portion 15c through the supply hole portion 18f. As shown in FIG. 13, the supply hole portion 18f opens to the side surface 18d. The supply hole portion 18f extends from the side surface 18d toward the front side (+X side) and diagonally downward.

The supply hole 18g connects the inside of the second gutter 18 to the inside of the bearing holder 15d. Therefore, a portion of the oil O that enters the second gutter 18 is supplied to the bearing 75 in the bearing holder 15d through the supply hole 18g. The supply hole 18g opens to the bottom surface 18c. The supply hole 18g extends downward and diagonally forward (+X side) from the bottom surface 18c.

2, the housing 10 has a first flow path 90 and a second flow path 50. That is, the drive unit 100 includes the first flow path 90 and the second flow path 50. The first flow path 90 is a flow path through which oil O flows as a first fluid. The second flow path 50 is a flow path through which water W flows as a second fluid. In this embodiment, the oil O and the water W function as a refrigerant that cools the stator 40. That is, in this embodiment, the second flow path 50 and the first flow path 90 are flow paths through which water W flows as a refrigerant that cools the stator 40. In this embodiment, at least a part of the second flow path 50 and at least a part of the first flow path 90 are composed of the first housing member 13, the second housing member 14, and the third housing member 15. Therefore, it is easy to increase the axial range in which the second flow path 50 and the first flow path 90 are provided, and it is easy to cool the stator 40.

In this specification, the term "flow path" refers to a path through which a fluid flows. Therefore, the term "flow path" is a concept that includes not only a "flow path" that creates a steady flow of fluid in one direction, but also a path that temporarily retains a fluid and a path through which a fluid drips. A path that temporarily retains a fluid includes, for example, a reservoir that stores a fluid.

At least a portion of the first flow path 90 is formed by the first housing member 13 and the third housing member 15. In this embodiment, the first flow path 90 is formed by the first housing member 13, the second housing member 14, and the third housing member 15. The first flow path 90 has a first supply flow path 91, a second supply flow path 92, a first recovery path 93x, and a second recovery path 93y. The first supply flow path 91 and the second supply flow path 92 are supply flow paths that supply the oil O in the transmission mechanism housing 12 to the inside of the motor housing 11. In other words, the first supply flow path 91 and the second supply flow path 92 are supply paths that supply the oil O contained in the transmission mechanism housing 12 to the motor 20.

The first supply flow passage 91 has a scooping path 91a, a shaft supply path 91b, a shaft internal path 91c, and a rotor internal path 90a. The scooping path 91a is a path through which the oil O in the transmission mechanism housing 12 is scooped up by the rotation of the ring gear 62a of the differential device 62 and enters the second gutter portion 18. The shaft supply path 91b is a path through which the oil O in the second gutter portion 18 flows into the bearing holding portion 16c through a flow path (not shown) provided in the cover wall portion 16a, and flows from the bearing holding portion 16c into the first gear shaft 63. The oil O flows into the bearing holding portion 16c in the shaft supply path 91b, and the oil O is supplied to the bearing 74 held by the bearing holding portion 16c. In the shaft supply path 91b of this embodiment, the oil O flows in from one axial end of the first gear shaft 63.

The shaft internal passage 91c is a passage through which oil O that has flowed into the first gear shaft 63 from one axial end of the first gear shaft 63 flows from inside the first gear shaft 63 to the motor shaft 31 on the other axial side. In other words, in this embodiment, the interior of the motor shaft 31 constitutes part of the first supply flow path 91. The rotor internal passage 90a is a passage through which oil O in the motor shaft 31 passes from the hole 33 through the interior of the rotor body 32 and splashes onto the stator 40. In this way, oil O is supplied to the rotor 30 and the stator 40 by the first supply flow path 91.

1, the second supply passage 92 has an inlet passage portion 92a, a connecting passage portion 92b, a shaft internal passage 92c, and a rotor internal passage 90a. The inlet passage portion 92a extends in the axial direction from inside the transmission mechanism housing 12. More specifically, the inlet passage portion 92a extends from inside the transmission mechanism housing 12 to the other axial side, passing through the second opposing wall portion 15a, the first opposing wall portion 13a, and the peripheral wall portion 13b, and extending to the second housing member 14. That is, the inlet passage portion 92a has a passage portion 92d provided in the first housing member 13, a passage portion 92e provided in the second housing member 14, and a passage portion 92f provided in the third housing member 15.

The flow passage portion 92f is connected to one axial side of the flow passage portion 92d. Therefore, the flow passage portion 92d and the flow passage portion 92f can suitably enlarge the first flow passage 90 in the axial direction. The flow passage portion 92e is connected to the other axial side of the flow passage portion 92d. Therefore, the flow passage portion 92d and the flow passage portion 92e can suitably enlarge the first flow passage 90 in the axial direction. The flow passage portion 92f penetrates the second opposing wall portion 15a in the axial direction and opens to the inside of the transmission mechanism housing 12. Therefore, the oil O in the transmission mechanism housing 12 can be caused to flow from the flow passage portion 92f into the introduction flow passage portion 92a. The oil O sucked from the inside of the transmission mechanism housing 12 by the pump 94 flows into the introduction flow passage portion 92a. In the introduction flow passage portion 92a, the oil O flows to the other axial side.

As shown in FIG. 3, the cross section of the inlet flow passage portion 92a is an ellipse that is long in the circumferential direction. The circumferential dimension of the inlet flow passage portion 92a is smaller than the circumferential dimension of the second recovery passage main body portion 93c described below, the circumferential dimension of the first circumferential flow passage portion 52a described below, and the circumferential dimension of the second circumferential flow passage portion 52b described below. Therefore, the circumferential dimension of the inlet flow passage portion 92a can be made relatively small. This reduces the pressure loss that occurs in the oil O flowing in the inlet flow passage portion 92a. Therefore, it is easier to send the oil O into the inlet flow passage portion 92a by the pump 94.

The introduction flow passage portion 92a is located, for example, forward (+X side) and below the central axis J1. At least a portion of the introduction flow passage portion 92a is located radially outside the second flow passage 50. In this embodiment, almost the entire introduction flow passage portion 92a, except for both axial ends, is located radially outside the second flow passage 50. The introduction flow passage portion 92a is located below the second flow passage 50.

As shown in FIG. 1, the connecting flow passage portion 92b is provided in the cover wall portion 14a of the second housing member 14. The connecting flow passage portion 92b extends upward from the end portion on the other axial side of the introduction flow passage portion 92a and connects to the recess 14c. As a result, the oil O flows into the recess 14c. A part of the oil O that flows into the recess 14c is supplied to the bearing 71 held by the bearing holding portion 14d. Another part of the oil O that flows into the recess 14c flows into the motor shaft 31 from the other axial side. The shaft internal path 92c is a path through which the oil O that flows into the motor shaft 31 from the end portion on the other axial side of the motor shaft 31 flows into the motor shaft 31 on one axial side. That is, in this embodiment, the inside of the motor shaft 31 constitutes a part of the second supply flow passage 92. Thus, in this embodiment, the oil O flows into the motor shaft 31 from both axial sides by the first supply flow passage 91 and the second supply flow passage 92. That is, oil O is supplied from both sides in the axial direction to the inside of the motor shaft 31. Therefore, compared to, for example, a case where oil O is flowed in from only one end of the motor shaft 31, oil O can be preferably flowed throughout the entire axial direction of the motor shaft 31. In other words, it is possible to prevent the oil O that flows in from one end of the motor shaft 31 from reaching the other end of the motor shaft 31 and not reaching the entire inside of the motor shaft 31. Therefore, it is easy to preferably supply oil O to each of the bearings 71, 74 that support both axial ends of the motor shaft 31. The oil O flowing through the shaft passage 92c flows through the rotor passage 90a in the same way as the shaft passage 91c, and is supplied to the rotor 30 and the stator 40.

The oil O supplied to the stator 40 by the first supply passage 91 and the second supply passage 92 removes heat from the stator 40. After cooling the stator 40, the oil O falls to the bottom and accumulates in the lower area of the motor housing 11. The oil O that accumulates in the lower area of the motor housing 11 returns to the inside of the transmission mechanism housing 12 via the first recovery passage 93x or the second recovery passage 93y.

2, the first recovery passage 93x is a flow path that returns the oil O supplied to the motor 20 to the inside of the transmission mechanism housing 12. The first recovery passage 93x extends from the inside of the motor housing 11 to the inside of the transmission mechanism housing 12. At least a portion of the first recovery passage 93x is formed by the first opening 13e and the second opening 15h. In this embodiment, the first recovery passage 93x is formed by the first opening 13e, a portion of the space S, and the second opening 15h. In other words, the first recovery passage 93x is formed by the through hole 19a. In this embodiment, the first recovery passage 93x is provided across the first housing member 13 and the third housing member 15.

The second recovery passage 93y is a flow path that returns the oil O supplied to the motor 20 to the inside of the transmission mechanism housing 12. The second recovery passage 93y extends from the inside of the motor housing 11 to the inside of the transmission mechanism housing 12. In this embodiment, the second recovery passage 93y is provided across the third housing member 15, the first housing member 13, and the second housing member 14. The second recovery passage 93y is located below the motor 20. The second recovery passage 93y has a groove portion 93a, a connection portion 93b, and a second recovery passage main body portion 93c. The groove portion 93a is provided on the inner circumferential surface of the motor housing 11. In this embodiment, the groove portion 93a is recessed downward from a portion located on the lower side of the inner circumferential surface of the first housing member 13. The groove portion 93a extends in the axial direction. One axial end of the groove portion 93a is blocked. The other axial end of the groove 93a opens into the other axial end face of the peripheral wall 13b. The other axial end of the groove 93a is connected to the connection portion 93b.

The bottom surface of the groove portion 93a is located lower as it approaches the other axial direction. In other words, the bottom surface of the groove portion 93a is an inclined surface that is located lower as it approaches the connection portion 93b. Therefore, the oil O that has entered the groove portion 93a can be easily guided to the connection portion 93b along the bottom surface of the groove portion 93a by utilizing gravity. The bottom surface of the groove portion 93a is the surface of the inner surface of the groove portion 93a that is located radially outward and faces radially inward. In this embodiment, the bottom surface of the groove portion 93a faces upward. As shown in FIG. 14, the circumferential dimension of the groove portion 93a is smaller than the circumferential dimension of the first opening 13e.

The connection portion 93b connects the groove portion 93a and the second recovery path main body portion 93c. The connection portion 93b is connected to the end portion 93f of the groove portion 93a on the other axial side. In this embodiment, the connection portion 93b is provided on the peripheral wall portion 14b of the second housing member 14. The connection portion 93b extends downward from a portion of the inner peripheral surface of the peripheral wall portion 14b that is located on the lower side. The connection portion 93b opens upward. As shown in FIG. 2, the lower end portion of the connection portion 93b is connected to the end portion 93g of the second recovery path main body portion 93c on the other axial side. As a result, the connection portion 93b connects the end portion 93f of the groove portion 93a on the other axial side and the end portion 93g of the second recovery path main body portion 93c on the other axial side.

The second recovery path main body 93c is located radially outward of the groove 93a. In this embodiment, the second recovery path main body 93c is located below the groove 93a. The second recovery path main body 93c extends in the axial direction and is connected to the inside of the transmission mechanism housing 12. The end 93p of the second recovery path main body 93c on one axial side opens into the inside of the transmission mechanism housing 12. In this embodiment, the second recovery path main body 93c is provided across the second housing member 14, the first housing member 13, and the third housing member 15. That is, the second recovery path main body 93c has a flow path portion 93h provided in the first housing member 13, a flow path portion 93i provided in the second housing member 14, and a flow path portion 93j provided in the third housing member 15. The end 93k on one axial side of the flow path portion 93h is connected to the end on the other axial side of the flow path portion 93j. The other axial end 93m of the flow passage portion 93h is connected to the one axial end of the flow passage portion 93i.

In this manner, in this embodiment, the first flow passage 90 has a flow passage portion 93h and a flow passage portion 93j that is connected to one axial side of the flow passage portion 93h. Therefore, the first flow passage 90 can be suitably enlarged in the axial direction by the flow passage portion 93h and the flow passage portion 93j. The flow passage portion 93j penetrates the second opposing wall portion 15a in the axial direction and opens into the interior of the transmission mechanism housing 12. Therefore, the oil O can be returned from the flow passage portion 93j to the inside of the transmission mechanism housing 12.

In this embodiment, the flow path portion 93h corresponds to a flow path portion extending in the axial direction. In other words, in this embodiment, the first housing member 13 has the flow path portion 93h as a flow path portion extending in the axial direction. In this embodiment, the flow path portion 93j corresponds to a "third opening" that opens into the inside of the transmission mechanism housing 12. The flow path portion 93j is provided in the second opposing wall portion 15a. In other words, in this embodiment, the second opposing wall portion 15a has the flow path portion 93j as a third opening that opens into the inside of the transmission mechanism housing 12. In this way, in this embodiment, at least a portion of the second recovery path 93y is composed of the flow path portion 93h extending in the axial direction and the flow path portion 93j as the third opening.

The second recovery path main body 93c extends axially from the lower end of the connection portion 93b to one side, axially penetrating the first housing member 13 and the third housing member 15, and opening into the interior of the transmission mechanism housing 12. Thus, in this embodiment, the first flow path 90 has the second recovery path main body 93c as a flow path portion that extends axially from the interior of the motor housing 11 to the interior of the transmission mechanism housing 12. The second recovery path main body 93c is located below the through hole 19a of the partition portion 19.

As shown in Figures 3 and 4, the flow passage cross section of the second recovery path main body 93c has a shape that is long in the circumferential direction. The circumferential dimension of the second recovery path main body 93c is larger than the circumferential dimension of the groove portion 93a and the circumferential dimension of the connection portion 93b. Therefore, the flow rate of oil O that can flow into the second recovery path main body 93c can be increased. This allows a larger amount of oil O to be returned from inside the motor housing 11 to inside the transmission mechanism housing 12.

At least a part of the second recovery path main body 93c is located radially outside the second flow path 50. As a result, at least a part of the second recovery path 93y is located radially outside the second flow path 50. Therefore, in this embodiment, at least a part of the second flow path 50 and the first flow path 90 overlap each other in the radial direction. In other words, the second flow path 50 and the first flow path 90 have overlapping parts when viewed in the radial direction. As shown in FIG. 14, a part of the second recovery path main body 93c is located below a pair of axial flow path sections 51 described later that are arranged circumferentially across the groove portion 93a of the second flow path 50, a first circumferential flow path section 52c described later that is located on one axial side of the groove portion 93a of the second flow path 50, and a pair of second circumferential flow path sections 52b described later that are arranged circumferentially across the connection portion 93b of the second flow path 50. In this embodiment, as described above, the circumferential dimension of the second recovery path main body 93c is larger than the circumferential dimension of the groove portion 93a and the circumferential dimension of the connection portion 93b, so the second recovery path main body 93c can protrude in the circumferential direction beyond the groove portion 93a and the connection portion 93b. Therefore, the second recovery path main body 93c can be easily positioned radially outside the second flow path 50.

The second recovery passage body 93c is disposed adjacent to one circumferential side (+θ side) of the inlet passage 92a. That is, in this embodiment, the inlet passage 92a is disposed adjacent to the second recovery passage 93y in the circumferential direction. In this embodiment, the portion of the motor housing 11 where the second recovery passage body 93c and the inlet passage 92a are provided protrudes downward more than the other portions of the motor housing 11.

The second recovery path main body 93c is provided with a partition wall portion 93d that divides the inside of the second recovery path main body 93c in the circumferential direction. The partition wall portion 93d extends in the axial direction from the end portion 93p on one axial side of the flow path portion 93h toward the other axial side. In this embodiment, the partition wall portion 93d extends from the end portion 93k on one axial side of the flow path portion 93h to the axial center of the flow path portion 93h. In other words, the partition wall portion 93d extends from the end portion on one axial side of the first housing member 13 to the axial center of the first housing member 13. The partition wall portion 93d divides the circumferentially long second recovery path main body portion 93c into approximately two equal parts in the circumferential direction. The partition wall portion 93d can improve the strength of the portion of the housing 10 where the second recovery path main body portion 93c is provided. In addition, the axial force of the second bolt 10b can be more effectively transmitted to the first housing member 13 and the third housing member 15.

The partition wall portion 93d does not have to extend to the axial center of the flow passage portion 93h, i.e., the axial center of the first housing member 13. For example, the end portion 93r on the other axial side of the partition wall portion 93d may be located anywhere as long as it is located on the other axial side of the end portion 93k on one axial side of the flow passage portion 93h and on the one axial side of the end portion 93m on the other axial side of the flow passage portion 93h.

As shown in FIG. 3, the second recovery path main body 93c has a recess 93e recessed radially inward. The recess 93e is located in the circumferential center of the other axial side portion of the second recovery path main body 93c. The outer peripheral surface of the portion of the motor housing 11 where the recess 93e is provided is recessed radially inward. This makes it possible to prevent, for example, the second bolt 10b that secures the first housing member 13 and the third housing member 15 from interfering with the second recovery path main body 93c.

1 and 2, at least a portion of the second flow path 50 is located radially outside the motor 20. In this embodiment, almost the entire second flow path 50, except for both axial ends, is located radially outside the motor 20. The lower portion of the second flow path 50 is located radially between the second recovery path main body 93c and the motor 20. As shown in FIGS. 14 and 15, in this embodiment, the second flow path 50 extends in a rectangular wave shape along the circumferential direction. The second flow path 50 has a plurality of axial flow path portions 51, a plurality of first circumferential flow path portions 52a, and a plurality of second circumferential flow path portions 52b.

The multiple axial flow passage sections 51 extend in the axial direction. The multiple axial flow passage sections 51 are arranged at intervals in the circumferential direction. In this embodiment, the axial flow passage sections 51 are provided in the motor housing 11. More specifically, the axial flow passage sections 51 are provided in the first housing member 13. As shown in FIG. 14, the two axial flow passage sections 51 located on the lower side among the multiple axial flow passage sections 51 are arranged with the groove section 93a sandwiched between them in the circumferential direction.

As shown in FIG. 1, the multiple axial flow passage sections 51 include an axial flow passage section 51c that is divided into two in the axial direction by a partition wall section 51d. The axial flow passage section 51c has an upstream side flow passage section 51a and a downstream side flow passage section 51b. In this embodiment, the upstream side flow passage section 51a is a portion of the axial flow passage section 51c that is located on one axial side of the partition wall section 51d. In this embodiment, the downstream side flow passage section 51b is a portion of the axial flow passage section 51c that is located on the other axial side of the partition wall section 51d.

As shown in FIG. 15, in this embodiment, the axial flow passage portion 51 is formed by at least a part of the hole 11a that axially penetrates the first housing member 13. The axial flow passage portion 51 is formed by, for example, a portion of the hole 11a excluding both axial ends. The opening on one axial side of the hole 11a is blocked by the third housing member 15. The opening on the other axial side of the hole 11a is blocked by the second housing member 14.

The first housing member 13 has a partition wall portion 52f that separates between circumferentially adjacent axial flow passage portions 51. The partition wall portion 52f extends in the axial direction. The axial dimension of the partition wall portion 52f is smaller than the axial dimension of the first housing member 13. The partition wall portion 52f includes a first partition wall portion 52d and a second partition wall portion 52e. There are multiple first partition wall portions 52d and multiple second partition wall portions 52e, which are arranged alternately in the circumferential direction.

The first partition wall portion 52d is a partition wall portion 52f that circumferentially separates a pair of axial flow passage portions 51 connected by the first circumferential flow passage portion 52a. The end portion on one axial side of the first partition wall portion 52d is disposed away from the end face on one axial side of the first housing member 13 on the other axial side. The end portion on the other axial side of the first partition wall portion 52d is located on the end face on the other axial side of the first housing member 13 and is in contact with the surface on one axial side of the second housing member 14.

The second partition wall portion 52e is a partition wall portion 52f that circumferentially separates a pair of axial flow passage portions 51 connected by the second circumferential flow passage portion 52b. The end portion on the other axial side of the second partition wall portion 52e is disposed away from the end face on the other axial side of the first housing member 13 on the other axial side. The end portion on the one axial side of the second partition wall portion 52e is located on the end face on the one axial side of the first housing member 13 and is in contact with the surface on the other axial side of the third housing member 15.

As shown in FIG. 14, the first circumferential flow passage section 52a and the second circumferential flow passage section 52b extend in the circumferential direction. The first circumferential flow passage sections 52a are arranged at intervals in the circumferential direction. The second circumferential flow passage sections 52b are arranged at intervals in the circumferential direction. The first circumferential flow passage section 52a connects the ends on one axial side of the circumferentially adjacent axial flow passage sections 51. The second circumferential flow passage section 52b connects the ends on the other axial side of the circumferentially adjacent axial flow passage sections 51. The first circumferential flow passage section 52a and the second circumferential flow passage section 52b alternately connect the ends on both axial sides of the axial flow passage sections 51, so that the second flow passage 50 has a rectangular wave shape.

The first circumferential flow passages 52a include a first circumferential flow passage 52c that circumferentially spans one axial side of the groove 93a. The first circumferential flow passage 52c is the first circumferential flow passage 52a located at the lowest position among the first circumferential flow passages 52a. The circumferential dimension of the first circumferential flow passage 52c is larger than the circumferential dimensions of the other first circumferential flow passages 52a. As shown in FIG. 5, the first opening 13e and the second opening 15h are located above the other circumferential side (-θ side) portion of the first circumferential flow passage 52c. The inner portion 52k of the first circumferential flow passage 52c provided in the first housing member 13 is located vertically between the first opening 13e and the flow passage portion 93h of the second recovery passage 93y provided in the first housing member 13. The outer portion 52m of the first circumferential flow passage portion 52c provided in the third housing member 15 is located vertically between the second opening 15h and the flow passage portion 93j of the second recovery passage 93y provided in the third housing member 15. In other words, in this embodiment, the second flow passage 50 has an inner portion 52k that is a portion located between the first opening 13e and the second recovery passage 93y, and an outer portion 52m that is a portion located between the second opening 15h and the second recovery passage 93y.

The multiple second circumferential flow passages 52b include a pair of second circumferential flow passages 52b that circumferentially sandwich the other axial end of the groove 93a and the connection portion 93b. In other words, in this embodiment, the other axial end of the groove 93a and the connection portion 93b are located between the second circumferential flow passages 52b that are adjacent to each other in the circumferential direction.

As shown in FIG. 15, in this embodiment, the first circumferential flow passage portion 52a is provided across the motor housing 11 and the transmission mechanism housing 12. More specifically, the first circumferential flow passage portion 52a is provided across the first housing member 13 and the third housing member 15. That is, at least a part of the first circumferential flow passage portion 52a is provided in the third housing member 15. Also, at least a part of the inner surface of the first circumferential flow passage portion 52a is the surface of the third housing member 15. The first circumferential flow passage portion 52a is configured by axially connecting a part provided on the end face on one axial side of the first housing member 13 and a first recess 52g recessed from the end face on the other axial side of the third housing member 15 to one axial side. The first recess 52g is a groove that extends in the circumferential direction and opens to the other axial side. In this way, the third housing member 15 has the first recess 52g recessed from the surface on the other axial side of the third housing member 15 to one axial side.

In this embodiment, the interior of the first circumferential flow passage portion 52a is composed of a first space portion 52i provided on one axial side of the first partition wall portion 52d in the first housing member 13 and the interior of the first recess 52g. The first space portion 52i includes, for example, a space portion adjacent to one axial side of the first partition wall portion 52d and space portions located on both circumferential sides of the space portion adjacent to the first partition wall portion 52d. The space portions located on both circumferential sides of the space portion adjacent to the first partition wall portion 52d are connected to the end portion on one axial side of the interior of the axial flow passage portion 51. The first space portion 52i includes the end portion on one axial side of the internal space of the hole 11a.

In this embodiment, the second circumferential flow passage portion 52b is provided across the first housing member 13 and the second housing member 14. That is, at least a part of the second circumferential flow passage portion 52b is provided in the second housing member 14. Also, at least a part of the inner surface of the second circumferential flow passage portion 52b is the surface of the second housing member 14. Also, in this embodiment, the second flow passage 50 is provided across the first housing member 13 and the second housing member 14. The second circumferential flow passage portion 52b is configured by axially connecting a part provided on the end face on the other axial side of the first housing member 13 and a second recess 52h recessed from the end face on one axial side of the second housing member 14 to the other axial side. The second recess 52h is a groove that extends in the circumferential direction and opens to one axial side. In this way, the second housing member 14 has the second recess 52h recessed from the surface on one axial side of the second housing member 14 to the other axial side.

In this embodiment, the interior of the second circumferential flow passage portion 52b is composed of a second space portion 52j provided on the other axial side of the second partition wall portion 52e in the first housing member 13 and the interior of the second recess 52h. The second space portion 52j includes, for example, a space portion adjacent to the other axial side of the second partition wall portion 52e and space portions located on both circumferential sides of the space portion adjacent to the second partition wall portion 52e. The space portions located on both circumferential sides of the space portion adjacent to the second partition wall portion 52e are connected to the end portion on the other axial side of the interior of the axial flow passage portion 51. The second space portion 52j includes the end portion on the other axial side of the internal space of the hole 11a.

In the axial flow passage section 51, water W flows in the axial direction. The directions in which water W flows in the axial flow passage sections 51 adjacent to each other in the circumferential direction are opposite to each other. In the first circumferential flow passage section 52a and the second circumferential flow passage section 52b, water W flows toward one circumferential side (+θ direction). The first circumferential flow passage section 52a connects the end of one axial side of the axial flow passage section 51 where water W flows toward one axial side and the end of one axial side of the axial flow passage section 51 where water W flows toward the other axial side. The second circumferential flow passage section 52b connects the end of the other axial side of the axial flow passage section 51 where water W flows toward the other axial side and the end of the other axial side of the axial flow passage section 51 where water W flows toward one axial side.

As shown in FIG. 1, the second flow path 50 has an inflow flow path section 53a and an outflow flow path section 53b. In this embodiment, the inflow flow path section 53a and the outflow flow path section 53b pass through the inside of the inverter unit 80. Water W flows into the inflow flow path section 53a from outside the drive device 100. The water W that flows into the inflow flow path section 53a flows into the upstream side flow path section 51a. The water W that flows into the upstream side flow path section 51a flows around the motor 20 while flowing along the rectangular wave-shaped flow path formed by the axial flow path section 51, the first circumferential flow path section 52a, and the second circumferential flow path section 52b, and flows into the outflow flow path section 53b from the downstream side flow path section 51b. The water W that flows into the outflow flow path section 53b flows out to the outside of the drive device 100.

As shown in FIG. 8, the fastening surfaces 13x, 14x of the first housing member 13 and the second housing member 14, which are fixed to each other by the first bolt 10a, are sealing surfaces that seal a part of the second flow path 50 at the connection part between the first housing member 13 and the second housing member 14. In other words, the axial space between the part of the first housing member 13 that constitutes the second flow path 50 and the part of the second housing member 14 that constitutes the second flow path 50 is sealed. Therefore, even if at least a part of the second flow path 50 is constituted by the first housing member 13 and the second housing member 14, it is possible to suppress leakage of water W from the second flow path 50.

The fastening surface 13x is the surface on the other axial side of the first housing member 13. The fastening surface 14x is the surface on one axial side of the second housing member 14. The fastening surfaces 13x, 14x also serve as sealing surfaces that seal a portion of the first flow path 90 at the connection portion between the first housing member 13 and the second housing member 14. Therefore, a portion of the second flow path 50 and a portion of the first flow path 90 at the connection portion between the first housing member 13 and the second housing member 14 can be sealed together by the first bolt 10a. This makes it easier to assemble the housing 10 compared to when the second flow path 50 and the first flow path 90 are sealed with different bolts. In addition, the number of parts of the drive unit 100 can be reduced.

The fastening surfaces 13y, 15y of the first housing member 13 and the third housing member 15, which are fixed to each other by the second bolt 10b, are sealing surfaces that seal a part of the second flow path 50 at the connection part between the first housing member 13 and the third housing member 15. In other words, the axial space between the part of the first housing member 13 that constitutes the second flow path 50 and the part of the third housing member 15 that constitutes the second flow path 50 is sealed. Therefore, even if at least a part of the second flow path 50 is constituted by the first housing member 13 and the third housing member 15, it is possible to suppress leakage of water W from the second flow path 50.

The fastening surface 13y is a surface on one axial side of the first housing member 13. The fastening surface 15y is a surface on the other axial side of the third housing member 15. The fastening surfaces 13y, 15y are also sealing surfaces that seal a part of the first flow path 90 at the connection portion between the first housing member 13 and the third housing member 15. Therefore, a part of the second flow path 50 and a part of the first flow path 90 at the connection portion between the first housing member 13 and the third housing member 15 can be sealed together by the second bolt 10b. This makes it easier to assemble the housing 10 compared to a case in which the second flow path 50 and the first flow path 90 are sealed with different bolts. In addition, the number of parts of the drive unit 100 can be reduced.

2, the housing 10 has an oil supply passage 95. The oil supply passage 95 extends from the inside of the transmission mechanism housing 12 through the second opposing wall portion 15a in the axial direction. In this embodiment, the oil supply passage 95 extends through the first opposing wall portion 13a in the axial direction to the inside of the motor housing 11. As shown in FIG. 7, the oil supply passage 95 has a supply port 13h that supplies oil O to the bearing 72 held by the first bearing holding portion 13c. In this embodiment, the supply port 13h is an opening of the first hole portion 13g that opens on the other axial side surface of the first opposing wall portion 13a. The supply port 13h opens into the inside of the motor housing 11. As shown in FIG. 3, the supply port 13h is located above the central axis J1. The supply port 13h opens into the inside of the through portion 13f. When viewed in the axial direction, the supply port 13h overlaps with the through portion 13f.

In this embodiment, the oil supply passage 95 has a first hole 13g, a second hole 15g, a first gutter 17, and a second gutter 18. As shown by the dashed arrow in FIG. 7, a portion of the oil O that is scooped up by the ring gear 62a and enters the second gutter 18 passes through the second hole 15g and flows into the first gutter 17 in the space S. The oil O that flows into the first gutter 17 flows through the first hole 13g and is supplied to the motor housing 11 from the supply port 13h. The oil O discharged from the supply port 13h flows into the first bearing holder 13c through the through-hole 13f and is supplied to the bearing 72.

According to this embodiment, at least a part of the second flow passage 50 is located radially outside the motor 20. Therefore, the motor 20 can be cooled by the water W flowing in the second flow passage 50. In this embodiment, the stator 40 can be cooled by the water W flowing in the second flow passage 50. In addition, at least a part of the second recovery passage 93y is located radially outside the second flow passage 50. Therefore, the second recovery passage 93y can be arranged close to the second flow passage 50. As a result, the water W flowing in the second flow passage 50 can easily cool the oil O passing through the second recovery passage 93y. Therefore, the temperature of the oil O flowing from the second recovery passage 93y into the transmission mechanism housing 12 can be lowered. Therefore, the temperature of the oil O supplied from the inside of the transmission mechanism housing 12 to the inside of the motor housing 11 by the first supply flow passage 91 and the second supply flow passage 92 can be relatively low. As a result, the motor 20 accommodated in the motor housing 11 can be supplied with a relatively low-temperature oil O. Therefore, the motor 20 can be suitably cooled by the relatively low-temperature oil O. In this way, in this embodiment, the motor 20 can be appropriately cooled by the water W and the oil O. This improves the cooling efficiency of the motor 20. In addition, the motor 20 can be easily cooled without providing a cooler such as an oil cooler to cool the oil O. Therefore, the number of parts in the drive unit 100 can be reduced by the amount that a cooler is not provided.

In addition, according to this embodiment, the second flow path 50 extends in a rectangular wave shape along the circumferential direction. Therefore, the portion of the housing 10 where the second flow path 50 is provided can be made wider, and the motor 20 can be more effectively cooled by the water W flowing through the second flow path 50. This further improves the cooling efficiency of the motor 20. In addition, when the housing 10 is divided into multiple members as in this embodiment, the second flow path 50 can be easily created by configuring the second flow path 50 with each member that configures the housing 10.

According to this embodiment, at least a part of the second flow passage 50 is formed by the first housing member 13 and the third housing member 15. Therefore, it is easy to make the second flow passage 50 longer on one axial side where the transmission mechanism housing 12 is located. This makes it easy to preferably cool the motor 20 by the second flow passage 50. Here, in this embodiment, as described above, the motor housing 11 and the transmission mechanism housing 12 are assembled with two housing members, respectively, so that the motor housing 11 and the transmission mechanism housing 12 can be separated. Due to this structure, the second flow passage 50 can be formed using the third housing member 15 that constitutes the transmission mechanism housing 12, and the second flow passage 50 can be more preferably provided large in the axial direction. In this embodiment, the second flow passage 50 can be extended to one axial side beyond the bearing 72 held by the first opposing wall portion 13a. As described above, according to this embodiment, the axial dimension of the second flow passage 50 provided in the housing 10 can be increased. Therefore, the cooling efficiency of the motor 20 by the second flow passage 50 can be improved.

In addition, in this embodiment, at least a portion of the first circumferential flow passage portion 52a is provided in the third housing member 15. Therefore, a portion of the second flow passage 50 can also be provided in the third housing member 15. This allows the second flow passage 50 to be preferably enlarged in the axial direction, making it easier to cool the motor 20 more preferably. In addition, in this embodiment, at least a portion of the second circumferential flow passage portion 52b is provided in the second housing member 14. Therefore, a portion of the second flow passage 50 can also be provided in the second housing member 14. This allows the second flow passage 50 to be more preferably enlarged in the axial direction, making it easier to cool the motor 20 more preferably.

In addition, in this embodiment, the second flow path 50 can be easily created by providing a hole 11a that penetrates the first housing member 13 in the axial direction and blocking both axial sides of the hole 11a with the second housing member 14 and the third housing member 15. In this embodiment, the opening on one axial side of the hole 11a is blocked by the third housing member 15, and the opening on the other axial side of the hole 11a is blocked by the second housing member 14. At least a part of the inner surface of the first circumferential flow path portion 52a is the surface of the third housing member 15. At least a part of the inner surface of the second circumferential flow path portion 52b is the surface of the second housing member 14. Therefore, the second flow path 50 can be easily created.

In addition, according to this embodiment, the first housing member 13 has a partition wall portion 52f that separates the axial flow passage portions 51 adjacent to each other in the circumferential direction. The axial dimension of the partition wall portion 52f is smaller than the axial dimension of the first housing member 13. Therefore, a gap can be provided between the partition wall portion 52f and the second housing member 14 in the axial direction, and between the partition wall portion 52f and the third housing member 15 in the axial direction. This makes it possible to easily configure a part of the second flow passage 50 by fixing at least one of the second housing member 14 and the third housing member 15 to the first housing member 13 using the gap.

Specifically, in this embodiment, the end of the first partition wall portion 52d on one axial side is located on the other axial side of the end of the first housing member 13 on one axial side. Therefore, a first space portion 52i is provided between the first partition wall portion 52d and the third housing member 15 in the axial direction. The interior of the first circumferential flow path portion 52a is composed of the first space portion 52i provided on one axial side of the first partition wall portion 52d in the first housing member 13 and the interior of the first recess 52g. This makes it possible to easily make the first circumferential flow path portion 52a straddling the first housing member 13 and the third housing member 15.

In addition, in this embodiment, the end portion on the other axial direction of the second partition wall portion 52e is located on one axial side of the end portion on the other axial direction of the first housing member 13. Therefore, a second space portion 52j is provided between the second partition wall portion 52e and the second housing member 14 in the axial direction. The interior of the second circumferential flow path portion 52b is composed of the second space portion 52j provided on the other axial direction side of the second partition wall portion 52e in the first housing member 13 and the interior of the second recess 52h. This makes it possible to easily make the second circumferential flow path portion 52b straddling the first housing member 13 and the second housing member 14.

In addition, according to this embodiment, the first circumferential flow passage portion 52a is provided across the first housing member 13 and the third housing member 15. Therefore, compared to a case where the entire first circumferential flow passage portion 52a is provided in the third housing member 15, for example, the third housing member 15 can be prevented from becoming large in the axial direction. This prevents the drive unit 100 from becoming large in the axial direction. In addition, since the second flow passage 50 can be suitably extended to one side of the stator 40 in the axial direction, the range of the stator 40 that can be cooled by the second flow passage 50 can be widened. This allows the motor 20 to be more suitably cooled by the water W flowing through the second flow passage 50.

In addition, according to this embodiment, the first bearing retaining portion 13c is provided on the other axial side of the first opposing wall portion 13a. Therefore, by forming at least a portion of the second flow passage 50 by the first housing member 13 and the third housing member 15, it is possible to easily position a portion of the second flow passage 50 on one axial side of the bearing 72 retained by the first bearing retaining portion 13c. This allows the axial dimension of the second flow passage 50 to be more suitably large relative to the motor 20. In addition, the bearing 72 is housed inside the motor housing 11. Therefore, when the motor housing 11 is separated from the transmission mechanism housing 12, the motor housing 11 and the motor 20 can be easily and suitably handled as a unit.

In addition, according to this embodiment, the transmission mechanism 60 has a first gear shaft 63 axially connected to the motor shaft 31. The motor shaft 31 and the first gear shaft 63 are connected to each other by spline fitting. Therefore, the motor shaft 31 and the first gear shaft 63 can be disconnected by moving the motor shaft 31 and the first gear shaft 63 away from each other in the axial direction. This makes it possible to easily disconnect the motor 20 and the transmission mechanism 60 when separating the motor housing 11 and the transmission mechanism housing 12 in the axial direction. Therefore, the motor housing 11 and the transmission mechanism housing 12 can be easily separated. Furthermore, when connecting the motor housing 11 and the transmission mechanism housing 12 in the axial direction, the motor 20 and the transmission mechanism 60 can be easily connected in the axial direction. Therefore, it is easy to connect the separated motor housing 11 and the transmission mechanism housing 12.

In addition, according to this embodiment, the third housing member 15 has a second bearing retaining portion 15c provided on one axial side of the second opposing wall portion 15a. Therefore, the bearing 73 that rotatably supports the first gear shaft 63 is housed inside the transmission mechanism housing 12. This makes it easy to conveniently handle the transmission mechanism housing 12 and the transmission mechanism 60 as a unit when the transmission mechanism housing 12 is separated from the motor housing 11.

In addition, according to this embodiment, the first flow path 90 has a first recovery path 93x that returns the oil O supplied to the motor 20 to the inside of the transmission mechanism housing 12. At least a portion of the first recovery path 93x is composed of the first opening 13e and the second opening 15h. Therefore, the oil O supplied to the motor 20 by the first supply flow path 91 and the second supply flow path 92 can be returned from inside the motor housing 11 to inside the transmission mechanism housing 12 by the first recovery path 93x.

In this structure in which a fluid such as oil O is moved between the motor housing 11 and the transmission mechanism housing 12 for cooling or the like, it has been difficult to separate the motor housing 11 and the transmission mechanism housing 12 independently in the past. Therefore, when the motor 20 or the transmission mechanism 60 breaks down, it is difficult to separate only the broken device, and it is difficult to replace or repair the device. In contrast, according to this embodiment, as described above, the motor housing 11 and the transmission mechanism housing 12 are each composed of two separate members, so that the motor housing 11 and the transmission mechanism housing 12 can be easily separated from each other. Therefore, according to this embodiment, in the drive device 100 having a structure in which oil O is moved between the motor housing 11 and the transmission mechanism housing 12, the motor 20 and the transmission mechanism 60 can be easily separated independently. As a result, when the motor 20 or the transmission mechanism 60 breaks down, it is possible to separate only the broken device. Therefore, it is easy to replace or repair the broken device.

In addition, according to this embodiment, the first opening 13e and the second opening 15h at least partially overlap each other when viewed in the axial direction. This makes it easier for oil O that flows from inside the motor housing 11 into the first opening 13e to flow through the second opening 15h into the transmission mechanism housing 12. This makes it easier for oil O to be returned from inside the motor housing 11 into the transmission mechanism housing 12 by the first recovery passage 93x.

In addition, according to this embodiment, the first opposing wall portion 13a and the second housing member 14 each hold bearings 71, 72 that rotatably support the motor shaft 31. The second opposing wall portion 15a and the fourth housing member 16 each hold bearings 73, 74 that rotatably support the first gear shaft 63. Therefore, by separating the motor housing 11 and the transmission mechanism housing 12, the unit including the motor housing 11 and the motor 20 can be suitably separated from the unit including the transmission mechanism housing 12 and the transmission mechanism 60.

In addition, according to this embodiment, when viewed in the axial direction, the width of the first opening 13e in the direction intersecting the vertical direction is wider on the lower side in the vertical direction. When viewed in the axial direction, the width of the second opening 15h in the direction intersecting the vertical direction is wider on the lower side in the vertical direction. This makes it easier for oil O that accumulates on the lower side of the motor housing 11 due to gravity to flow to the first opening 13e and the second opening 15h. This makes it easier for the first recovery path 93x to return oil O from the motor housing 11 to the transmission mechanism housing 12.

In addition, according to this embodiment, the opening area of the opening end 15w of the second opening 15h that opens into the inside of the transmission mechanism housing 12 is larger than the opening area of the opening end 13w of the first opening 13e that opens into the inside of the motor housing 11. Therefore, it is possible to prevent the oil O that flows into the first opening 13e from inside the motor housing 11 from clogging between the first opening 13e and the second opening 15h. This allows the oil O that flows into the first opening 13e to flow more suitably into the inside of the transmission mechanism housing 12 via the second opening 15h. Therefore, the first recovery passage 93x makes it easier to return the oil O from inside the motor housing 11 to the inside of the transmission mechanism housing 12.

In addition, according to this embodiment, the first flow path 90 has a second recovery path 93y that returns the oil O supplied to the motor 20 to the inside of the transmission mechanism housing 12. Therefore, the oil O supplied into the motor housing 11 can be returned into the transmission mechanism housing 12 from the second recovery path 93y in addition to the first recovery path 93x. This increases the amount of oil O returned from the motor housing 11 to the transmission mechanism housing 12. In addition, at least a part of the second recovery path 93y is composed of a flow path portion 93h extending in the axial direction provided in the first housing member 13 and a flow path portion 93j as a third opening provided in the second opposing wall portion 15a. Therefore, the second recovery path 93y can be easily and suitably configured across the first housing member 13 and the third housing member 15.

According to this embodiment, the second recovery passage 93y has a groove 93a provided on the inner peripheral surface of the motor housing 11 and extending in the axial direction, a second recovery passage body 93c located radially outward of the groove 93a and extending in the axial direction to connect to the inside of the transmission mechanism housing 12, and a connection portion 93b connecting the groove 93a and the second recovery passage body 93c. Therefore, at least a portion of the oil O supplied to the motor housing 11 by the first supply flow passage 91 and the second supply flow passage 92 can be made to flow from the groove 93a into the second recovery passage 93y. In addition, the oil O that has flowed into the groove 93a can be sent into the transmission mechanism housing 12 via the connection portion 93b and the second recovery passage body 93c. This makes it easier for the second recovery passage 93y to return the oil O in the motor housing 11 to the transmission mechanism housing 12. In addition, according to this embodiment, at least a portion of the second recovery passage body 93c is located radially outside the second flow passage 50. Therefore, the oil O flowing in the second recovery passage body 93c is easily cooled by the water W flowing in the second flow passage 50.

In addition, according to this embodiment, the connection portion 93b connects the other axial end of the groove portion 93a and the other axial end of the second recovery path main body portion 93c. In other words, the position where the connection portion 93b connects the groove portion 93a and the second recovery path main body portion 93c can be located relatively far from the transmission mechanism housing 12 in the axial direction. Therefore, the distance that the oil O flows from the connection portion 93b into the second recovery path main body portion 93c until it reaches the inside of the transmission mechanism housing 12 can be increased. This increases the time that the oil O flowing in the second recovery path main body portion 93c can be cooled by the water W flowing in the second flow path 50. Therefore, the oil O flowing in the second recovery path main body portion 93c can be suitably cooled by the water W flowing in the second flow path 50. Therefore, it is possible to easily supply lower temperature oil O to the motor 20. This can further improve the cooling efficiency of the motor 20.

According to this embodiment, the first circumferential flow passages 52a include a first circumferential flow passage 52c that circumferentially spans one axial side of the groove 93a. The connection portion 93b is located between the second circumferential flow passages 52b that are adjacent to each other in the circumferential direction. In this way, by having the first circumferential flow passage 52c span the groove 93a on the axial side opposite to the side on which the connection portion 93b is provided, the connection portion 93b can be extended from the radial inner side of the second flow passage 50 to the radial outer side of the second flow passage 50 without interfering with the second flow passage 50. This allows at least a portion of the second recovery path main body 93c to be positioned radially outside the second flow passage 50 without interfering with the second flow passage 50.

In addition, according to this embodiment, the second supply flow passage 92 has an introduction flow passage portion 92a extending axially from the inside of the transmission mechanism housing 12. At least a portion of the introduction flow passage portion 92a is located radially outside the second flow passage 50. Therefore, the introduction flow passage portion 92a can be arranged close to the second flow passage 50. This makes it easier for the water W flowing through the second flow passage 50 to cool the oil O passing through the introduction flow passage portion 92a. Therefore, the temperature of the oil O supplied to the inside of the motor housing 11 by the second supply flow passage 92 can be made relatively low. Therefore, the motor 20 housed in the motor housing 11 can be more suitably cooled by the oil O. Therefore, the cooling efficiency of the motor 20 can be further improved.

In addition, according to this embodiment, the inlet flow passage portion 92a is arranged adjacent to the second recovery passage 93y in the circumferential direction. Therefore, the inlet flow passage portion 92a and the second recovery passage 93y can be arranged together. This makes it possible to prevent the structure of the housing 10 from becoming complicated.

In addition, according to this embodiment, the second recovery passage 93y and the second flow passage 50 are provided across the first housing member 13 and the second housing member 14, respectively. Therefore, the second recovery passage 93y and the second flow passage 50 can each be made large in the axial direction. This makes it easier to increase the portion of the second recovery passage 93y that is arranged close to the second flow passage 50. Therefore, the oil O flowing in the second recovery passage 93y can be more easily cooled by the water W flowing in the second flow passage 50. In addition, by making the second flow passage 50 large in the axial direction, the range of the motor 20 that can be cooled by the water W flowing in the second flow passage 50 can be made wider in the axial direction. This makes it easier to cool the entire stator core 41 and the coil ends 42a, 42b protruding from the stator core 41 on both sides in the axial direction by the water W flowing in the second flow passage 50. As a result, the cooling efficiency of the motor 20 can be further improved.

In addition, according to this embodiment, the first flow passage 90 has a second recovery passage main body 93c as a flow passage portion that extends axially from the inside of the motor housing 11 to the inside of the transmission mechanism housing 12. At least a portion of the second flow passage 50 and the first flow passage 90 overlap each other in the radial direction. Therefore, the oil O flowing in the second recovery passage main body 93c is easily cooled by the water W flowing in the second flow passage 50. As a result, the oil O in the first flow passage 90 is easily cooled by the water W in the second flow passage 50 over a wide range in the axial direction of the first flow passage 90.

In addition, according to this embodiment, the second flow passage 50 has an inner portion 52k that is a portion located between the first opening 13e and the second recovery passage 93y, and an outer portion 52m that is a portion located between the second opening 15h and the second recovery passage 93y. Therefore, the oil O flowing in the second recovery passage 93y can be more easily cooled by the water W flowing in the second flow passage 50.

In addition, according to this embodiment, the first housing member 13 and the second housing member 14 are fixed to each other at a position radially inside the second recovery passage 93y and adjacent to the second flow passage 50 in the circumferential direction. In this embodiment, the first housing member 13 and the second housing member 14 are fixed to each other at this position by the fourth bolt 10d fastened to the female screw hole 13i. This allows the first housing member 13 and the second housing member 14 to be fixed at a position close to both the second recovery passage 93y and the second flow passage 50. Therefore, it is possible to prevent the parts of the first housing member 13 and the second housing member 14 that respectively constitute the second recovery passage 93y from being separated from each other. In addition, it is possible to prevent the parts of the first housing member 13 and the second housing member 14 that respectively constitute the second flow passage 50 from being separated from each other. This prevents oil O from leaking from the second recovery passage 93y and water W from leaking from the second flow passage 50. In addition, it is possible to prevent the oil O leaking from the second recovery passage 93y from entering the second flow passage 50 and mixing with the water W. It is also possible to prevent the water W leaking from the second flow passage 50 from entering the second recovery passage 93y and mixing with the oil O.

For example, in the present embodiment, when the housing 10 is composed of two separate members constituting the motor housing 11 and two separate members constituting the transmission mechanism housing 12, the motor housing 11 and the transmission mechanism housing 12 are provided separately. In such cases, conventionally, structures for lubricating the bearings were provided separately in the motor housing 11 and the transmission mechanism housing 12. This resulted in problems such as a complex structure of the housing 10 or an increase in the manufacturing costs of the drive unit 100 due to the use of relatively expensive bearings that do not require the supply of lubricating oil. An example of a relatively expensive bearing that does not require the supply of lubricating oil is a bearing that is provided with semi-solid grease.

In contrast, according to the present embodiment, the housing 10 has an oil supply passage 95 that extends from inside the transmission mechanism housing 12 through the second opposing wall portion 15a in the axial direction. The oil supply passage 95 has a supply port 13h that supplies oil O to the bearing 72 held by the first opposing wall portion 13a in the motor housing 11. The supply port 13h is located above the central axis J1. Therefore, the oil O discharged from the supply port 13h can be made to fall by gravity and supplied to the bearing 72 provided in the motor housing 11 among the bearings supporting the rotor 30 that can rotate around the central axis J1. In other words, the oil supply passage 95 can supply a portion of the oil O in the transmission mechanism housing 12 to the bearing 72 provided in the motor housing 11. In this way, the bearing lubrication structure provided in the transmission mechanism housing 12 can be used to lubricate the bearing 72 provided in the motor housing 11. In other words, in the drive unit 100, the motor housing 11 and the transmission mechanism housing 12 can be configured to be separable, while the bearing 72 provided in the motor housing 11 can be lubricated using the oil O in the transmission mechanism housing 12. This prevents the structure of the housing 10 from becoming complicated, and there is no need to use a bearing that does not require the supply of lubricating oil as the bearing 72. This prevents the manufacturing costs of the drive unit 100 from increasing.

In addition, according to this embodiment, the first bearing retaining portion 13c is provided on the surface on the other axial side of the first opposing wall portion 13a. The oil supply passage 95 axially penetrates the first opposing wall portion 13a and extends to the inside of the motor housing 11. The supply port 13h opens into the inside of the motor housing 11. Therefore, even if the bearing 72 retained by the first bearing retaining portion 13c is located inside the motor housing 11, the oil supply passage 95 can supply oil O to the bearing 72.

In addition, according to this embodiment, the first bearing retaining portion 13c has a through portion 13f that penetrates the first bearing retaining portion 13c in the radial direction. The supply port 13h opens into the inside of the through portion 13f. Therefore, the oil O discharged from the supply port 13h is easily supplied from the through portion 13f to the inside of the first bearing retaining portion 13c. This makes it easier to supply the oil O to the bearing 72.

According to this embodiment, the oil supply passage 95 has a first hole 13g penetrating the first opposing wall portion 13a in the axial direction, a second hole 15g penetrating the second opposing wall portion 15a in the axial direction, and a first gutter portion 17 located between the first opposing wall portion 13a and the second opposing wall portion 15a in the axial direction and connecting the first opposing wall portion 13a and the second opposing wall portion 15a. The first gutter portion 17 is connected to a portion of the surface on one axial side of the first opposing wall portion 13a that is located below the first hole portion 13g and a portion of the surface on the other axial side of the second opposing wall portion 15a that is located below the second hole portion 15g. Therefore, the oil O in the transmission mechanism housing 12 can be supplied to the motor housing 11 through the second hole portion 15g, the first gutter portion 17, and the first hole portion 13g in this order. This allows the oil O in the transmission mechanism housing 12 to be more efficiently supplied to the bearings 72 in the motor housing 11.

In addition, according to this embodiment, the oil supply passage 95 has a second gutter portion 18 located inside the transmission mechanism housing 12. The second gutter portion 18 is connected to a portion of the surface on one axial side of the second opposing wall portion 15a that is located below the second hole portion 15g. Therefore, for example, a portion of the oil O that is scattered inside the transmission mechanism housing 12 due to being scooped up by the ring gear 62a can be received by the second gutter portion 18. In addition, at least a portion of the oil O received by the second gutter portion 18 can flow into the second hole portion 15g. This allows the oil O in the transmission mechanism housing 12 to be more suitably supplied to the bearing 72 in the motor housing 11 via the second hole portion 15g, the first gutter portion 17, and the first hole portion 13g in this order.

In addition, according to this embodiment, the second opposing wall portion 15a has a second opening 15h that connects the space S located axially between the first opposing wall portion 13a and the second opposing wall portion 15a to the inside of the transmission mechanism housing 12. Therefore, for example, oil O that leaks from the first gutter portion 17 can be returned to the inside of the transmission mechanism housing 12 via the second opening 15h. This makes it possible to prevent the oil O from accumulating in the space S.

In addition, according to this embodiment, the first opposing wall portion 13a has a first opening 13e that connects the space S located axially between the first opposing wall portion 13a and the second opposing wall portion 15a to the inside of the motor housing 11. Therefore, the first opening 13e, the space S, and the second opening 15h can connect the inside of the motor housing 11 to the inside of the transmission mechanism housing 12. This forms the above-mentioned through hole 19a, and at least a portion of the oil O supplied to the motor housing 11 can be returned to the inside of the transmission mechanism housing 12.

The present invention is not limited to the above-described embodiment, and other configurations and methods may be adopted within the scope of the technical concept of the present invention. The first flow path may have any configuration as long as it has a supply path and a first recovery path. In the above-described embodiment, the supply path is configured to include the first supply path 91 and the second supply path 92, but is not limited to this. Only one of the first supply path 91 and the second supply path 92 may be provided as the supply path.

The first recovery passage that returns the first fluid supplied to the motor to the inside of the transmission mechanism housing may have any configuration as long as it is at least partially constituted by the first opening and the second opening. The first opening and the second opening may or may not entirely overlap each other when viewed in the axial direction. The shape and size of the first opening are not particularly limited. The shape and size of the second opening are not particularly limited.

The second recovery passage that returns the first fluid supplied to the motor to the inside of the transmission mechanism housing may have any configuration. When the motor housing has a first housing member and a second housing member, the second recovery passage may be provided only in the first housing member in the motor housing. There are no particular limitations on the shape and size of the groove portion that constitutes the second recovery passage, the shape and size of the connection portion that constitutes the second recovery passage, and the shape and size of the second recovery passage main body that constitutes the second recovery passage. The second recovery passage does not have to be provided.

The second flow passage may have any shape. The second flow passage may be formed only by the first housing member, or may be formed only by the first housing member and the second housing member. The first circumferential flow passage portion does not have to be provided across the first housing member and the third housing member. The second circumferential flow passage portion does not have to be provided across the first housing member and the second housing member. The number of axial flow passage portions is not particularly limited as long as it is two or more. The number of first circumferential flow passage portions and the number of second circumferential flow passage portions are not particularly limited as long as it is one or more.

When the first circumferential flow passage is formed by the first housing member and the third housing member, the third housing member may not be provided with a first recess. In this case, the first circumferential flow passage may be formed by closing a first space provided on one axial side of the first partition wall in the first housing member with a surface on the other axial side of the third housing member. When the second circumferential flow passage is formed by the first housing member and the second housing member, the second recess may not be provided in the second housing member. In this case, the second circumferential flow passage may be formed by closing a second space provided on the other axial side of the second partition wall in the first housing member with a surface on one axial side of the second housing member.

The type of the first fluid flowing inside the first flow path and the type of the second fluid flowing inside the second flow path are not particularly limited. The first fluid and the second fluid may be the same type of fluid. The first fluid may be an insulating liquid or may be water. If the first fluid is water, the surface of the stator may be subjected to an insulating treatment. The second fluid may be oil. The second flow path may not be provided.

The oil supply passage extending from inside the transmission mechanism housing through the second opposing wall in the axial direction may have any configuration as long as it has a supply port located above the central axis and supplies oil to the bearing. When the bearing holder provided on the first opposing wall of the motor housing is provided on one axial side of the first opposing wall, that is, on the surface of the first opposing wall facing the transmission mechanism housing, the oil supply passage may only pass through the second opposing wall and may not pass through the first opposing wall. In this case, for example, the supply port of the oil supply passage opens into the space between the first opposing wall and the second opposing wall. The oil supply passage may not have at least one of the first hole, the second hole, the first gutter, and the second gutter. The oil supply passage may be formed of a tubular member such as a pipe. The oil supply passage may not be provided.

The use of the drive device to which the present invention is applied is not particularly limited. For example, the drive device may be mounted on a vehicle for a purpose other than rotating an axle, or may be mounted on equipment other than a vehicle. The attitude of the drive device when used is not particularly limited. The central axis of the motor may be inclined with respect to a horizontal direction perpendicular to the vertical direction, or may extend in the vertical direction. The configurations described in this specification above can be combined as appropriate within a range that does not contradict each other.

10...housing, 10a...first bolt, 10b...second bolt, 10c...third bolt, 11...motor housing, 11a...hole, 12...transmission mechanism housing, 13...first housing member, 13a...first opposing wall portion, 13e...first opening, 13p, 15q, 15r...female thread hole (bolt hole), 13q, 14p, 16r...fixing hole (through hole), 14...second housing member, 13c...first bearing retaining portion (bearing retaining portion), 15...third housing member, 15a...second opposing wall portion, 15h...second opening, 16...fourth housing member, 20...motor, 30...rotor, 31...motor shaft, 40...stator, 50...second flow path, 60...transmission mechanism, 63...first gear shaft (gear shaft), 71, 72, 73, 74...bearing, 90...first flow path, 91...first supply flow path (supply path), 92...second supply flow path (supply path), 93h...flow path portion, 93j...flow path portion (third opening), 93x...first return path, 93y...second return path, 100...driver, J1...center shaft, O...oil (first fluid), W...water (second fluid)

Claims (9)

A motor having a rotor rotatable about a central axis and a stator covering the outside of the rotor in a radial direction;
A transmission mechanism connected to the motor;
a housing including a motor housing that accommodates the motor therein, and a transmission mechanism housing that is fixed to one axial side of the motor housing and accommodates the transmission mechanism and a first fluid therein;
a first flow path through which the first fluid flows;
Equipped with
The first flow path is
a supply passage that supplies the first fluid contained inside the transmission mechanism housing to the motor;
a first return passage for returning the first fluid supplied to the motor to an inside of the transmission mechanism housing;
a second return passage for returning the first fluid supplied to the motor to an inside of the transmission mechanism housing;
having
The motor housing includes:
a first housing member fixed to the transmission mechanism housing;
a second housing member fixed to the other axial side of the first housing member;
having
The transmission mechanism housing includes:
a third housing member fixed to the first housing member;
a fourth housing member fixed to one axial side of the third housing member;
having
the housing has a partition wall portion that separates an interior of the motor housing from an interior of the transmission mechanism housing,
The partition wall portion is
a first opening that opens into the motor housing;
a second opening that opens into the inside of the transmission mechanism housing;
a bearing holder that holds a bearing that rotatably supports the rotor;
having
At least a portion of the first recovery path is formed by the first opening and the second opening,
The second recovery path is
a third opening that opens into the inside of the transmission mechanism housing;
a flow passage portion provided in the first housing member and extending in an axial direction;
a portion that is connected to the flow passage portion and opens into the motor housing on the other axial side of the stator core of the stator;
A drive device having the above structure. The drive device according to claim 1, wherein the first opening and the second opening at least partially overlap each other when viewed in the axial direction. The rotor has an axially extending motor shaft,
the transmission mechanism includes a gear shaft axially connected to the motor shaft,
a bearing that rotatably supports the motor shaft is held in each of the partition wall and the second housing member,
3. The drive unit according to claim 1, wherein the partition portion and the fourth housing member each hold a bearing that rotatably supports the gear shaft. The drive unit according to claim 1 , wherein the bearing holder is provided on the other axial side of the partition wall . When viewed in the axial direction, the width of the first opening in a direction intersecting the vertical direction is wider on a lower side in the vertical direction,
The drive device according to claim 1 , wherein a width of the second opening in a direction intersecting the vertical direction as viewed in the axial direction is wider on a lower side in the vertical direction. a second flow path through which a second fluid flows;
The second flow path is
a portion located between the first opening and the second recovery path;
a portion located between the second opening and the second recovery path;
The drive arrangement according to claim 1 , further comprising: A motor having a rotor rotatable about a central axis and a stator covering the outside of the rotor in a radial direction;
A transmission mechanism connected to the motor;
a housing including a motor housing that accommodates the motor therein, and a transmission mechanism housing that is fixed to one axial side of the motor housing and accommodates the transmission mechanism and a first fluid therein;
a first flow path through which the first fluid flows;
a second flow path through which a second fluid flows;
Equipped with
The first flow path is
a supply passage that supplies the first fluid contained inside the transmission mechanism housing to the motor;
a first return passage for returning the first fluid supplied to the motor to an inside of the transmission mechanism housing;
a second return passage for returning the first fluid supplied to the motor to an inside of the transmission mechanism housing;
having
The motor housing includes:
a first housing member fixed to the transmission mechanism housing;
a second housing member fixed to the other axial side of the first housing member;
having
The transmission mechanism housing includes:
a third housing member fixed to the first housing member;
a fourth housing member fixed to one axial side of the third housing member;
having
the housing has a partition wall portion that separates an interior of the motor housing from an interior of the transmission mechanism housing,
The partition wall portion is
a first opening that opens into the motor housing;
a second opening that opens into the inside of the transmission mechanism housing;
a bearing holder that holds a bearing that rotatably supports the rotor;
having
At least a portion of the first recovery path is formed by the first opening and the second opening,
The second flow path is
a portion located between the first opening and the second recovery path;
a portion located between the second opening and the second recovery path;
A drive device having the above structure. The rotor has an axially extending motor shaft,
The motor shaft is a hollow shaft that is open on both axial sides,
The inside of the motor shaft constitutes a part of the supply passage,
The drive device according to claim 1 , wherein the first fluid is supplied to an inside of the motor shaft from both axial sides. the second housing member is fixed to the other axial side of the first housing member by a plurality of first bolts,
the third housing member is fixed to the first housing member by a plurality of second bolts;
the fourth housing member is fixed to one axial side of the third housing member by a plurality of third bolts,
the first bolts that fix the first housing member and the second housing member are passed through a plurality of through holes provided in the second housing member from the other axial side, respectively, and fixed to a plurality of bolt holes provided in the first housing member,
the second bolts that fix the first housing member and the third housing member are passed through a plurality of through holes provided in the first housing member from the other axial side, respectively, and fixed to a plurality of bolt holes provided in the third housing member,
9. A drive device as described in any one of claims 1 to 8, wherein the plurality of third bolts fixing the third housing member and the fourth housing member are each passed through a plurality of through holes provided in the fourth housing member from one axial side and fixed to a plurality of bolt holes provided in the third housing member.

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