JP7664980B2 - Motor Unit - Google Patents

Description

The present invention relates to a motor unit.

In recent years, there has been active development of drive units to be installed in electric vehicles. Patent Document 1 describes a motor unit that is connected to a PDU (power drive unit) that houses an inverter. In recent years, development of motor units with integrated inverters has been progressing.

JP 2010-268633 A

When the inverter is integrated with the motor unit, the problem is that the dimensions of the motor unit tend to become larger.

One aspect of the present invention aims to provide a motor unit that can be miniaturized by integrating an inverter.

One embodiment of the motor unit of the present invention includes a motor having a rotor rotatable around a motor shaft and a stator, a transmission mechanism that transmits the power of the motor and outputs it from an output shaft, a housing having a motor accommodating section that accommodates the motor and a gear accommodating section that accommodates the transmission mechanism, an inverter unit that supplies power to the motor, oil that circulates through an oil passage provided in the housing, and an oil cooler that is provided in the path of the oil passage and cools the oil, and at least a portion of the inverter unit overlaps the oil cooler when viewed in the axial direction of the motor shaft.

According to one aspect of the present invention, a motor unit is provided that has an integrated inverter and can be made compact.

FIG. 1 is a conceptual diagram of a motor unit according to an embodiment. FIG. 2 is a perspective view of the motor unit according to the embodiment. FIG. 3 is a side view of the motor unit according to one embodiment. FIG. 4 is an exploded perspective view of the motor unit according to one embodiment. FIG. 5 is an exploded perspective view of the motor unit according to one embodiment. FIG. 6 is a schematic cross-sectional view of the motor unit.

The motor unit according to the embodiment of the present invention will be described below with reference to the drawings. Note that the scope of the present invention is not limited to the following embodiment, and can be modified as desired within the scope of the technical concept of the present invention. In addition, in the following drawings, the scale and number of each structure may differ from the actual structure in order to make each configuration easier to understand.

In the following description, the direction of gravity is defined based on the positional relationship when the motor unit 10 is mounted on a vehicle positioned on a horizontal road surface. In addition, 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 indicates the vertical direction (i.e., the up-down direction), the +Z direction is the upper side (opposite the direction of gravity), and the -Z direction is the lower side (direction of gravity). Therefore, in this specification, when simply referring to the upper side, it means the upper side with respect to the direction of gravity. In addition, the X axis direction is a direction perpendicular to the Z axis direction and indicates the front-to-rear direction of the vehicle on which the motor unit 10 is mounted, the +X direction is the front of the vehicle, and the -X direction is the rear of the vehicle. The Y axis direction is a direction perpendicular to both the X axis direction and the Z axis direction and indicates the width direction of the vehicle (left-right direction), the +Y direction is the left side of the vehicle, and the -Y direction is the right side of the vehicle.

Fig. 1 is a conceptual diagram of a motor unit 10 according to an embodiment of the present invention. Fig. 2 is a perspective view of the motor unit 10.
It should be noted that the motor shaft J1, counter shaft J3, output shaft J4, rotation shaft J6, first central shaft J7c and second central shaft J7e described below are imaginary shafts that do not actually exist.

The motor unit 10 is mounted on a vehicle and drives the vehicle by rotating the wheels H. The motor unit 10 is mounted, for example, on an electric vehicle (EV). The motor unit 10 may be mounted on any vehicle that uses a motor as a power source, such as a hybrid electric vehicle (HEV) or a plug-in hybrid electric vehicle (PHV).

As shown in FIG. 1, the motor unit 10 includes a motor 1, a transmission mechanism (transaxle) 5, a housing 6 that accommodates the motor 1 and the transmission mechanism 5, an oil pump 96, an oil cooler 97, a park lock mechanism 7, oil O, and an inverter unit 8.

(housing)
The housing 6 is made of, for example, aluminum die casting. The housing 6 is formed by connecting a plurality of members arranged along the vehicle width direction. An accommodation space 6S is provided inside the housing 6 for accommodating the motor 1 and the transmission mechanism 5. The housing 6 holds the motor 1 and the transmission mechanism 5 in the accommodation space 6S. The accommodation space 6S is partitioned into a motor chamber 6A for accommodating the motor 1 and a gear chamber 6B for accommodating the transmission mechanism 5.

The housing 6 has a motor accommodating section 62 having a motor chamber 6A therein and accommodating the motor 1, a gear accommodating section 63 having a gear chamber 6B therein and accommodating the transmission mechanism 5, and a partition wall section 61 that separates the motor chamber 6A from the gear chamber 6B. The partition wall section 61 is located between the motor accommodating section 62 and the gear accommodating section 63 in the axial direction.

An oil reservoir P in which oil O accumulates is provided in the lower region of the storage space 6S. A partition wall opening 61a is provided in the partition wall portion 61 that separates the motor chamber 6A and the gear chamber 6B. The partition wall opening 61a connects the motor chamber 6A and the gear chamber 6B. Oil O in the storage space 6S moves between the motor chamber 6A and the gear chamber 6B through the partition wall opening 61a.

An oil passage 90 for circulating oil O is provided in the storage space 6S. The oil O is supplied from the oil reservoir P to each part of the motor unit 10 through the oil passage 90. The oil passage 90 will be described in detail later.

(oil)
The oil O accumulates inside the housing. The oil O circulates through an oil passage 90 provided in the housing 6. The oil O is used to lubricate the transmission mechanism 5 and to cool the motor 1. The oil O accumulates in a lower region (i.e., oil reservoir P) of the accommodation space 6S. Since the oil O functions as a lubricating oil and a cooling oil, it is preferable to use an oil equivalent to a low-viscosity lubricating oil for automatic transmissions (ATF: Automatic Transmission Fluid).

A part of the motor 1 is immersed in the oil O that accumulates in the oil reservoir P. More specifically, a part of the stator 32 of the motor 1 is immersed in the oil O in the oil reservoir P. In this way, the oil O cools the stator 32.

In addition, part of the transmission mechanism 5 is immersed in the oil O in the oil pool P. More specifically, part of the ring gear 51 of the transmission mechanism 5 is immersed in the oil O in the oil pool P. The oil O that has accumulated in the oil pool P is scooped up by the operation of the ring gear 51 and spreads into the gear chamber 6B. The oil O that has spread into the gear chamber 6B is supplied to each gear of the transmission mechanism 5 in the gear chamber 6B, spreading the oil O over the gear tooth surfaces. The oil O that has been supplied to the transmission mechanism 5 and used for lubrication drips down and is collected in the oil pool P.

(Oil passage)
The oil passage 90 is provided in the housing 6. The oil passage 90 is configured to straddle the motor chamber 6A and the gear chamber 6B of the accommodation space 6S. The oil passage 90 is a path for the oil O that supplies the oil O from the oil sump P to the motor 1 and leads the oil O back to the oil sump P.

In this specification, "oil passage" refers to the path of oil O circulating in the storage space 6S. Therefore, the concept of "oil passage" includes not only a "flow path" that creates a steady flow of oil in one direction, but also a path that temporarily retains oil (e.g., oil reservoir P) and a path along which oil drips.

An oil pump 96 and an oil cooler 97 are provided in the oil passage 90. In the oil passage 90, the oil O circulates through the oil reservoir P, the oil pump 96, the oil cooler 97, and the motor 1, and then returns to the oil reservoir P.

The oil pump 96 is provided in the oil passage 90 and pumps the oil O. The oil pump 96 is an electric pump that is driven by electricity. The oil pump 96 is fixed to the gear accommodating portion 63 of the housing 6.

As shown in FIG. 2, the oil pump 96 is provided in the housing 6 and accommodated in the oil pump accommodation hole 69. The oil pump accommodation hole 69 extends along the axial direction. The oil pump accommodation hole 69 opens to the left side in the vehicle width direction (+Y direction). The inner peripheral surface of the oil pump accommodation hole 69 has an intake port (not shown) that draws oil O into the oil pump 96, and an exhaust port (not shown) that pumps the oil O downstream.

It has a pump motor 96m and a pump mechanism (not shown) that is driven by the pump motor 96m. The pump motor 96m is exposed outside the opening of the oil pump housing hole 69. The pump mechanism is housed inside the oil pump housing hole 69.

The rotation axis J6 of the pump motor 96m is parallel to the motor shaft J1. That is, the pump motor 96m rotates about the rotation axis J6 that is parallel to the motor shaft J1. An oil pump 96 having a pump motor 96m tends to be long in the direction of the rotation axis J6. According to this embodiment, by making the rotation axis J6 of the pump motor 96m parallel to the motor shaft J1, the dimensions of the motor unit 10 can be reduced in the radial direction of the motor shaft J1.

The pump mechanism is, for example, a trochoidal pump in which an external gear and an internal gear mesh and rotate. In this case, the internal gear of the pump mechanism is rotated by a pump motor 96m. The gap between the internal gear and the external gear of the pump mechanism is connected to the intake port and the discharge port.

As shown in FIG. 1, the oil pump 96 draws up oil O from an oil reservoir P through a flow passage provided in the housing. The oil pump 96 supplies the drawn up oil O to an oil cooler 97.

The oil cooler 97 is provided in the oil passage 90 and cools the oil O passing through the oil passage 90. The oil cooler 97 is fixed to the gear accommodating portion 63 of the housing 6. A refrigerant pipe 97j, which passes a refrigerant cooled by a radiator (not shown), is connected to the oil cooler 97. The oil O passing through the inside of the oil cooler 97 is cooled by heat exchange with the refrigerant passing through the refrigerant pipe 97j. The inverter unit 8 is provided in the path of the refrigerant pipe 97j. That is, the inverter unit 8 and the oil cooler 97 are connected to each other by a pipe (refrigerant pipe 97j) that constitutes the refrigerant passage. The refrigerant passing through the refrigerant pipe 97j cools not only the oil O passing through the oil cooler 97 but also the inverter unit 8.

Oil O that has passed through the oil cooler 97 is supplied to the motor 1 at the upper side of the motor chamber 6A through a flow path provided in the housing 6. The oil O supplied to the motor 1 flows from the top to the bottom along the outer circumferential surface of the motor 1 and the coil surface of the stator 32, removing heat from the motor 1. This allows the entire motor 1 to be cooled. The oil O that has cooled the motor 1 drips downward and accumulates in the lower region of the motor chamber 6A. The oil O that has accumulated in the lower region of the motor chamber 6A moves to the gear chamber 6B through the partition opening 61a provided in the partition section 61.

(Motor)
The motor 1 is a motor-generator that functions both as an electric motor and as a generator. The motor 1 mainly functions as an electric motor to drive the vehicle, and functions as a generator during regeneration.

As shown in FIG. 1, the motor 1 has a rotor 31 and a stator 32 that surrounds the rotor 31. The rotor 31 is rotatable about the motor shaft J1. The stator 32 is annular. The stator 32 surrounds the rotor 31 from the radial outside of the motor shaft J1.

The rotor 31 is fixed to the motor drive shaft 11, which will be described later. The rotor 31 rotates around the motor axis J1. The rotor 31 has a rotor core and a rotor magnet held by the rotor core.

The stator 32 has a stator core and a coil. The stator core has multiple teeth that protrude radially inward from the motor shaft J1. The coil is wound around the teeth of the stator core.

The motor 1 is connected to an inverter 8a. The inverter 8a converts direct current supplied from a battery (not shown) into alternating current and supplies it to the motor 1. Each rotation speed of the motor 1 is controlled by controlling the inverter 8a.

(Transmission mechanism)
The transmission mechanism 5 transmits the power of the motor 1 and outputs it from an output shaft 55. The transmission mechanism 5 incorporates a plurality of mechanisms responsible for transmitting power between the driving source and the driven device.

The transmission mechanism 5 has a motor drive shaft 11, a motor drive gear 21, a counter shaft 13, a counter gear (large gear portion) 23, a drive gear (small gear portion) 24, a ring gear 51, an output shaft (axle) 55, and a differential device (differential gear) 50.

Each gear and shaft of the transmission mechanism 5 can rotate around either the motor shaft J1, the counter shaft J3, or the output shaft J4. In this embodiment, the motor shaft J1, the counter shaft J3, and the output shaft J4 extend parallel to one another. The motor shaft J1, the counter shaft J3, and the output shaft J4 are also parallel to the width direction of the vehicle. In the following description, the axial direction means the axial direction of the motor shaft J1. In other words, the axial direction means the direction parallel to the motor shaft J1 and the width direction of the vehicle.

The motor drive shaft 11 extends along the motor axis J1. The motor drive shaft 11 is fixed to the rotor 31. The motor drive shaft 11 is rotated by the motor 1. The motor drive gear 21 is fixed to the motor drive shaft 11.

The motor drive shaft 11 extends in the axial direction around the motor axis J1. The motor drive shaft 11 is a hollow shaft that opens on both axial sides of the motor axis J1. The external shape of the motor drive shaft 11 as viewed along the axial direction is a cylinder with the motor axis J1 at its center. The motor drive shaft 11 is supported by bearings so that it can rotate around the motor axis J1. An output shaft 55 passes through the inside of the motor drive shaft 11.

The motor drive gear 21 is fixed to the motor drive shaft 11. The motor drive gear 21 rotates around the motor axis J1 together with the motor drive shaft 11.

The countershaft 13 extends along the counter axis J3. The countershaft 13 rotates around the counter axis J3. The countershaft 13 is rotatably held, for example, via a bearing (not shown) in a case (not shown) that houses the transmission mechanism 5. A counter gear 23, a drive gear 24, and a park lock gear 7a are fixed to the countershaft 13.

The counter gear 23 is fixed to the counter shaft 13. The counter gear 23 rotates around the counter axis J3 together with the counter shaft 13. The counter gear 23 meshes with the motor drive gear 21.

The drive gear 24 is fixed to the counter shaft 13. The drive gear 24 rotates around the counter axis J3 together with the counter shaft 13 and the counter gear 23. The drive gear 24 is disposed on the opposite side of the motor 1 from the counter gear 23 in the axial direction.

The park lock gear 7a is part of the parking lock mechanism 7. The park lock gear 7a is fixed to the counter shaft 13. The park lock gear 7a rotates around the counter axis J3 together with the counter shaft 13, the counter gear 23, and the drive gear 24. The park lock gear 7a is disposed between the counter gear 23 and the drive gear 24 in the axial direction.

The ring gear 51 is fixed to the differential device 50. The ring gear 51 rotates around the output shaft J4. The ring gear 51 meshes with the drive gear 24. The ring gear 51 transmits the power of the motor 1, which is transmitted via the drive gear 24, to the differential device 50.

The differential gear 50 is a device for transmitting the torque output from the motor 1 to the wheels H of the vehicle. The differential gear 50 has the function of transmitting the same torque to the output shafts 55 of both the left and right wheels while absorbing the speed difference between the left and right wheels H when the vehicle turns.

The differential device 50 has a gear housing (not shown) fixed to the ring gear 51, a pair of pinion gears (not shown), a pinion shaft (not shown), and a pair of side gears (not shown). The gear housing rotates around the output shaft J4 together with the ring gear 51. The gear housing accommodates the pair of pinion gears, the pinion shaft, and the pair of side gears. The pair of pinion gears are bevel gears that face each other. The pair of pinion gears are supported by the pinion shaft. The pair of side gears are bevel gears that mesh with the pair of pinion gears at right angles. The pair of side gears are each fixed to the output shaft 55.

The output shaft 55 rotates around the output axis J4. The motor unit 10 is provided with a pair of output shafts 55. One end of each of the pair of output shafts 55 is connected to a side gear of the differential device 50. That is, the output shaft 55 is connected to the ring gear 51 via the differential device 50. The power of the motor 1 is transmitted to the output shaft 55 via each gear. The other end of each of the pair of output shafts 55 protrudes outside the housing 6. The wheel H is attached to the other end of the output shaft 55. The output shaft 55 outputs the power to the outside (to the road surface via the wheel H).

In this embodiment, the output shaft J4 coincides with the motor shaft J1. In addition, one of the pair of output shafts 55 passes through the interior of the motor drive shaft 11, which is a hollow shaft. Therefore, the motor unit 10 of this embodiment can be made smaller in the radial direction of the motor shaft J1 than a motor unit having a structure in which the motor shaft J1 and the output shaft J4 are not arranged coaxially.

FIG. 3 is a side view of the motor unit 10 according to one embodiment.
The transmission mechanism 5 constitutes a power transmission path from the motor 1 to the output shaft 55. In the power transmission path of the transmission mechanism 5, the power of the motor 1 is first transmitted from the motor drive gear 21 to the counter gear 23. The counter gear 23 is disposed coaxially with the drive gear 24 and rotates together with the drive gear 24. The power of the motor 1 is transmitted from the drive gear 24 to the ring gear 51, and is then transmitted to the output shaft 55 via the differential device 50.

(Positional relationship of each axis)
As shown in FIG. 3, the counter shaft J3 is located above the motor shaft J1. Since the motor shaft J1 coincides with the output shaft J4, the counter shaft J3 is located above the output shaft J4. According to this embodiment, the centers of the counter gear 23 and the drive gear 24 are arranged to be shifted in the vertical direction with respect to the centers of the motor 1 and the ring gear 51 when viewed from the axial direction. The drive gear 24 and the ring gear 51 mesh with each other, so that their absolute distance is uniquely determined. Therefore, by arranging the motor shaft J1 and the counter shaft J3 to be shifted in the vertical direction, the dimensional component of the counter shaft J3 and the motor shaft J1 in the vehicle longitudinal direction can be shortened. As a result, the dimension of the motor unit 10 in the vehicle longitudinal direction can be reduced, and a wide crushable zone can be secured in the vehicle.

In addition, in this embodiment, the counter gear 23 and the drive gear 24 are positioned above the motor shaft J1. That is, the lower ends of the counter gear 23 and the drive gear 24 are both positioned above the motor shaft J1. As a result, the drive gear 24 can be positioned so that it overlaps the ring gear 51 largely when viewed from the top-bottom direction, making it possible to further reduce the dimensions of the motor unit 10 in the vehicle front-to-rear direction.

As shown in FIG. 3, the line segment that virtually connects the motor shaft J1 and the counter shaft J3 when viewed in the axial direction is the first line segment L1. The first line segment L1 and the vertical line VL extending in the vertical direction form an angle α. The angle α is preferably within 45°. In other words, the first line segment L1 preferably extends in a direction within 45° of the vertical direction (gravity direction). This allows the motor unit 10 to have a smaller dimension in the vehicle's fore-and-aft direction. It is more preferable that the angle α is within 20°. In other words, the first line segment L1 preferably extends in a direction within 20° of the vertical direction. This allows the motor unit 10 to have a smaller dimension in the vehicle's fore-and-aft direction.

The counter shaft J3 is located on the rear side of the vehicle (-X direction) from the motor shaft J1. As described above, a part of the ring gear 51 is immersed in the oil O in the oil reservoir P, and the oil O is scooped up by the ring gear 51. When the vehicle moves forward, the ring gear 51 rotates in the rotation direction T1 shown in FIG. 3. The rotation direction T1 is the direction in which the ring gear 51 rotates upward on the rear side of the vehicle. Therefore, the oil O scooped up by the ring gear 51 is scattered more efficiently on the rear side of the vehicle. According to this embodiment, the counter shaft J3 is located on the rear side of the vehicle from the motor shaft J1, so that the oil O scooped up by the ring gear 51 can be efficiently supplied to the counter gear 23 and the drive gear 24. This increases the lubricity of the tooth surfaces of the counter gear 23 and the drive gear 24, and increases the power transmission efficiency of the transmission mechanism 5.

As shown in FIG. 3, the oil pump 96 is located above the motor shaft J1. That is, the lower end of the oil pump 96 is located above the motor shaft J1. According to this embodiment, the vehicle longitudinal dimension of the motor unit 10 can be made smaller than when the oil pump and the motor shaft J1 are arranged side by side in the vehicle longitudinal direction. As a result, the vehicle longitudinal dimension of the motor unit 10 can be made smaller, making it possible to ensure a wide crushable zone within the vehicle.

The oil pump 96 is disposed diagonally above and in front of the vehicle relative to the motor shaft J1. That is, the oil pump 96 is located above the motor shaft J1 and further forward of the vehicle (+X direction) than the motor shaft J1. As described above, above the motor shaft J1, the counter gear 23 and the drive gear 24 are located further rearward of the vehicle (-X direction) than the motor shaft J1. Therefore, in this embodiment, the oil pump 96, the counter gear 23 and the drive gear 24 can be disposed above the motor shaft J1, offset in the fore-and-aft direction of the vehicle. This allows the motor unit 10 to be made more compact.

As described above, the oil pump 96 has a pump motor 96m that rotates around a rotation axis J6 parallel to the motor shaft J1. As shown in FIG. 3, a line segment that virtually connects the motor shaft J1 and the rotation axis J6 when viewed from the axial direction is defined as a second line segment L2. The second line segment L2 and a vertical line VL extending in the vertical direction form an angle β. The angle β is preferably within 45°. That is, the second line segment L2 preferably extends in a direction within 45° to the vertical direction. This allows the motor unit 10 to be further reduced in size in the vehicle longitudinal direction. Moreover, the angle β is more preferably within 35°. That is, the second line segment L2 preferably extends in a direction within 35° to the vertical direction. This allows the motor unit 10 to be further reduced in size in the vehicle longitudinal direction.

The oil cooler 97 is located above the motor shaft J1. That is, the lower end of the oil cooler 97 is located above the motor shaft J1. According to this embodiment, the vehicle longitudinal dimension of the motor unit 10 can be made smaller than when the oil cooler and the motor shaft J1 are arranged side by side in the vehicle longitudinal direction.

The oil cooler 97 is disposed adjacent to the oil pump 96 above the motor shaft J1. The oil cooler 97 and the oil pump 96 are connected to each other via a flow path provided in the housing 6. By disposing the oil cooler 97 and the oil pump 96 adjacent to each other, the flow path connecting the oil cooler 97 and the oil pump 96 can be shortened. This allows the flow path that constitutes the oil passage 90 to be shortened, and the circulation efficiency of the oil O in the oil passage 90 can be improved.

The oil cooler 97 is located forward of the motor shaft J1 (in the +X direction). In other words, the oil cooler 97 is disposed diagonally above and in front of the vehicle relative to the motor shaft J1. According to this embodiment, the oil cooler 97 can be air-cooled when the vehicle is moving forward, and the efficiency of cooling the oil O by the oil cooler 97 can be improved.

(Parking lock mechanism)
The park lock mechanism 7 is actuated based on a shift operation by the driver and is switched between a locked state in which the power transmission in the transmission mechanism 5 is restricted and an unlocked state in which the restriction is lifted.

As shown in FIG. 3, the parking lock mechanism 7 has a parking lock gear 7a, a parking lock arm 7b, an arm support shaft 7e, a parking lock actuator 7c, and a parking lock power transmission mechanism 7d.

The park lock gear 7a is fixed to the countershaft 13. The park lock gear 7a rotates around the countershaft J3 together with the countershaft 13. The outer peripheral surface of the park lock gear 7a is provided with a plurality of teeth that protrude radially outward from the countershaft J3 and are aligned circumferentially around the countershaft J3.

The park lock arm 7b is plate-shaped and extends along a plane perpendicular to the axial direction. The park lock arm 7b is rotatably supported by an arm support shaft 7e that is centered on a second central axis J7e that extends in the axial direction. The park lock arm 7b extends upward from the arm support shaft 7e.

The park lock arm 7b extends along the outer peripheral surface of the park lock gear 7a. The park lock arm 7b faces the teeth of the park lock gear 7a in the radial direction of the counter shaft J3. The park lock arm 7b has a meshing portion 7ba that faces the teeth of the park lock gear 7a. The meshing portion 7ba protrudes toward the inside in the radial direction of the counter shaft J3. The meshing portion 7ba meshes with the teeth of the park lock gear 7a. That is, the park lock arm 7b meshes with the park lock gear at the meshing portion 7ba.

The park lock arm 7b is driven by a park lock actuator 7c and rotates within a predetermined range around a second central axis J7e.
When the parking lock mechanism 7 is locked by the driver, the parking lock arm 7b rotates counterclockwise around the second central axis J7e in Fig. 3, and the meshing portion 7ba meshes with the teeth of the parking lock gear 7a. This restricts the rotation of the countershaft 13, and limits the transmission of power in the transmission mechanism 5.
On the other hand, when the parking lock mechanism 7 is unlocked by the driver's operation, the parking lock arm 7b rotates clockwise around the second central axis J7e, and the meshing portion 7ba is released from the teeth of the parking lock gear 7a. This allows the countershaft 13 to rotate freely, and the transmission mechanism 5 is ready to transmit power.

According to this embodiment, the parking lock arm 7b extends in the vertical direction. When viewed from the axial direction, the countershaft 13 and the parking lock arm 7b are arranged side by side in the vehicle fore-and-aft direction. This makes it possible to reduce the vertical dimension of the motor unit 10. Also, when viewed from the axial direction, a portion of the parking lock arm 7b overlaps with the counter gear 23. This makes it possible to prevent the vehicle fore-and-aft direction dimension of the motor unit 10 from becoming large, even if the parking lock arm 7b and the countershaft 13 are arranged side by side in the vehicle fore-and-aft direction.

The park lock power transmission mechanism 7d is located between the park lock actuator 7c and the park lock arm 7b. The park lock power transmission mechanism 7d transmits the power of the manual shaft 7ca, which rotates around the first central axis J7c, to the park lock arm 7b, causing the park lock arm 7b to rotate around the second central axis J7e.

The park lock actuator 7c has a manual shaft 7ca centered on a first central axis J7c that extends in the vertical direction. The park lock actuator 7c rotates the manual shaft 7ca centered on the first central axis J7c. The park lock actuator 7c drives the park lock arm 7b via the park lock power transmission mechanism 7d.

The park lock actuator 7c is fixed to the upper side of the housing 6. More specifically, the park lock actuator 7c is located directly above the counter shaft J3. In other words, when viewed from the top-bottom direction, the park lock actuator 7c overlaps with the counter shaft J3. This allows the horizontal dimension of the motor unit 10 to be reduced.

As shown in FIG. 2, the park lock actuator 7c is fixed to the outer surface of the gear housing 63 of the housing 6. The park lock actuator 7c is located on the gear housing 63 side of the partition wall 61 of the housing 6. That is, according to this embodiment, the park lock actuator 7c does not overlap the partition wall 61 when viewed from the top-bottom direction. In order to maintain the strength of the entire housing 6, the partition wall 61 has a shape that protrudes radially outward from the motor shaft J1 relative to the motor 1 and the transmission mechanism 5. According to this embodiment, since the park lock actuator 7c and the partition wall 61 do not overlap when viewed from the top-bottom direction, the axial projection area of the motor unit 10 is prevented from becoming enlarged, and the motor unit 10 can be made smaller.

As shown in FIG. 1, the parking lock gear 7a is located between the counter gear 23 and the drive gear 24 in the axial direction of the counter shaft J3. According to this embodiment, the parking lock gear 7a can be located closer to the partition wall 61 than when the parking lock gear is located on the opposite side of the partition wall 61 from the counter gear 23 and the drive gear 24. This prevents the parking lock arm 7b, which is located along the outer periphery of the parking lock gear 7a, from being positioned so as to protrude radially outward from the counter shaft J3, thereby enabling the motor unit 10 to be made more compact.

(Inverter unit)
2, the inverter unit 8 includes an inverter 8a and an inverter case 8b that houses the inverter 8a. Although not shown, the inverter unit 8 further includes a circuit board and a capacitor.

The inverter unit 8 is generally rectangular when viewed from above and below. The inverter unit 8 is fixed to the outer surface of the housing 6. More specifically, the inverter unit 8 is fixed to the outer surface of the motor accommodating section 62 of the housing 6 in the inverter case 8b. The inverter unit 8 is connected to a bus bar (not shown) of the motor 1 on the upper side of the motor 1. The inverter unit 8 supplies AC current to the motor 1 via the bus bar. In this way, the inverter unit 8 supplies power to the motor 1.

The inverter unit 8 is located directly above the motor 1. In other words, the inverter unit 8 is located above the motor 1 and overlaps the motor 1 when viewed from the top-bottom direction. This allows the dimensions of the motor unit 10 in the vehicle's fore-and-aft direction to be reduced compared to when the inverter unit 8 is disposed relative to the motor 1 in the vehicle's fore-and-aft direction. As a result, it is possible to ensure a wide crushable zone within the vehicle.

Generally, the axial projection area of the motor housing 62 is smaller than the axial projection area of the gear housing 63. According to this embodiment, the inverter unit 8 is disposed radially outside the motor housing 62, so that it is easy to arrange the inverter unit 8 overlapping the gear housing 63 when viewed from the axial direction. This allows the axial projection area of the entire motor unit 10 to be reduced, and the motor unit 10 can be made more compact.

As shown in FIG. 3, when viewed from the axial direction, at least a portion of the inverter unit 8 overlaps with the counter gear 23. By arranging the inverter unit 8 overlapping with the counter gear 23, the axial projection area of the motor unit 10 can be reduced, thereby making the motor unit 10 more compact.

At least a portion of the inverter unit 8 overlaps the oil pump 96 when viewed in the axial direction. Similarly, at least a portion of the inverter unit 8 overlaps the oil cooler 97 when viewed in the axial direction. By arranging the inverter unit 8 overlapping the oil pump 96 and the oil cooler 97, the axial projection area of the motor unit 10 can be reduced, making the motor unit 10 more compact.

Figures 4 and 5 are exploded perspective views of the motor unit 10, with the inverter unit 8 separated from the housing 6. Figures 4 and 5 show different perspective directions of the motor unit 10.

As shown in Figures 4 and 5, the inverter unit 8 is fixed to the housing 6 of the motor unit 10 at multiple fixing parts 40, 45. The multiple fixing parts 40, 45 are classified into a first fixing part 40 (see Figure 4) and a second fixing part 45 (see Figure 5). The first fixing part 40 is located on the vehicle front side relative to the motor shaft J1, and the second fixing part 45 is located on the vehicle rear side relative to the motor shaft J1.

As shown in FIG. 4, the first fixing portion 40 has a visor portion 42 provided on the inverter unit 8, an opposing surface 43 provided on the housing 6, and a fixing bolt 41.

The eaves portion 42 of the first fixing portion 40 protrudes horizontally from the outer surface of the inverter case 8b of the inverter unit 8. The eaves portion 42 has a through hole 42a that penetrates in the vertical direction.

The opposing surface 43 of the first fixing part 40 faces the eaves part 42 in the vertical direction. In this embodiment, the opposing surface 43 is provided on the housing 6 located below the inverter unit 8. Therefore, in this embodiment, the opposing surface 43 of the first fixing part 40 faces upward. The opposing surface 43 is provided with a screw hole 43a that extends in the vertical direction and opens to the eaves part 42 side (i.e., the upper side).

The fixing bolt 41 of the first fixing part 40 is screwed into the screw hole 43a of the opposing surface 43 through the through hole 42a of the eaves part 42. This brings the underside of the eaves part 42 into contact with the opposing surface 43, and the inverter unit 8 and the housing 6 are fixed to each other.

As shown in FIG. 5, the second fixing portion 45 has a visor portion 47 provided on the housing 6, an opposing surface 48 provided on the inverter unit 8, and a fixing bolt 46.

The eaves portion 47 of the second fixing portion 45 protrudes horizontally from the outer surface of the motor accommodating portion 62 of the housing 6. The eaves portion 47 has a through hole 47a that penetrates in the vertical direction.

The opposing surface 48 of the second fixing portion 45 faces the eaves portion 47 in the vertical direction. In this embodiment, the opposing surface 48 is provided on the inverter unit 8 located on the upper side of the housing 6. Therefore, in this embodiment, the opposing surface 48 of the second fixing portion 45 faces downward. A screw hole 48a is provided on the opposing surface 48, which extends in the vertical direction and opens to the eaves portion 47 side (i.e., the lower side).

The fixing bolt 46 of the second fixing portion 45 is screwed into the screw hole 48a of the opposing surface 48 through the through hole 47a of the eaves portion 47. This brings the upper surface of the eaves portion 47 into contact with the opposing surface 48, and the inverter unit 8 and the housing 6 are fixed to each other.

The first fixing part 40 and the second fixing part 45 are disposed on opposite sides of the motor shaft J1 when viewed from the top-bottom direction. In addition, the eaves parts 42, 47 of the first fixing part 40 and the second fixing part 45 each protrude in a direction away from the motor shaft J1 when viewed from the top-bottom direction.

According to this embodiment, the eaves 42 of the first fixing part 40 and the eaves 47 of the second fixing part 45, which are located on opposite sides of the motor shaft J1, are provided separately on the inverter unit 8 and the housing 6, respectively. Therefore, the dimensions of the motor unit 10 in the vehicle fore-and-aft direction can be made smaller than when all the eaves are provided on either the inverter unit 8 or the housing 6.

Figure 6 is a schematic cross-sectional view of the motor unit 10. Note that detailed structures of each part (e.g., the coil of the stator 32, the rotor magnet of the rotor 31, etc.) are omitted in Figure 6.

The inverter unit 8 has a bottom surface 8s that faces the housing 6. The bottom surface 8s is a flat surface along the horizontal direction. When viewed from the top-bottom direction, the bottom surface 8s of the inverter unit 8 is surrounded by multiple fixing parts (first fixing part 40 and second fixing part 45). In other words, the multiple fixing parts 40, 45 are arranged around the bottom surface 8s.

As shown in Figures 4 and 5, a first rib 62a and a second rib 62b that protrude along the radial direction of the motor shaft J1 are provided on the outer surface of the motor accommodating section 62 of the housing 6. The first rib 62a extends along the axial direction of the motor shaft J1. The first rib 62a is located directly above the motor 1. The second rib 62b extends along the circumferential direction of the motor shaft J1.

As shown in FIG. 6, the first rib 62a and the second rib 62b are provided with a notched surface 62s that is cut along the lower surface 8s of the inverter unit 8. That is, the outer surface of the housing 6 is provided with the notched surface 62s. The notched surface 62s is a flat surface that is aligned in the horizontal direction. The notched surface 62s faces the lower surface 8s of the inverter unit 8 in the vertical direction with a gap therebetween.

A surface pressure is applied to the contact surface between the housing 6 and the inverter unit 8 at the first fixing part 40 and the second fixing part 45 by the fixing bolts 41, 46. Therefore, at the first fixing part 40 and the second fixing part 45, the housing 6 and the inverter unit 8 are integrally connected. On the other hand, when the housing 6 and the inverter unit 8 contact each other in an area where no surface pressure is applied, the vibration of the housing 6 caused by the operation of the motor 1 and the transmission mechanism 5 is transmitted to the inverter unit 8, and the inverter unit 8 may be excited. When the inverter unit 8 is excited, there is a risk that each part of the inverter unit 8 (inverter 8a, circuit board, capacitor, etc.) may be damaged. According to this embodiment, in the area surrounded by the fixing parts 40, 45 when viewed from the top and bottom, the housing 6 and the inverter unit 8 are separated in the vertical direction. This makes it possible to suppress the vibration of the housing 6 from being transmitted to the inverter unit 8 and exciting the inverter unit 8.

The above describes the embodiments and modifications of the present invention, but each configuration and combination of the embodiments and modifications is merely an example, and additions, omissions, substitutions and other modifications of configurations are possible without departing from the spirit of the present invention. Furthermore, the present invention is not limited to the embodiments.

1...motor, 5...transmission mechanism, 6...housing, 7...parking lock mechanism, 7a...parking lock gear, 7b...parking lock arm, 7c...parking lock actuator, 8...inverter unit, 8a...inverter, 8s...underside, 10...motor unit, 11...motor drive shaft, 13...counter shaft, 21...motor drive gear, 23...counter gear, 24...drive gear, 40...first fixed part (fixed part), 45...second fixed part (fixed part), 41, 46...fixing bolt, 42, 47...eaves, 42a, 47a...through hole, 43, 48...opposing surface, 43a, 48a...screw hole, 51...ring gear, 55...output shaft, 61...partition, 62...motor housing, 62s...notch, 63...gear housing, 90...oil passage, 96...oil pump, 96m...pump motor, 97...oil cooler, J1...motor shaft, J3...counter shaft, J4...output shaft, J6...rotating shaft, L1...first line segment, L2...second line segment, O...oil, P...oil reservoir

Claims (12)

A motor unit mounted on a vehicle to drive the vehicle,
A motor having a rotor rotatable around a motor shaft and a stator;
a transmission mechanism that transmits the power of the motor and outputs it from an output shaft;
a housing having a motor accommodating portion that accommodates the motor and a gear accommodating portion that accommodates the transmission mechanism;
an inverter unit that supplies power to the motor;
Oil circulating through an oil passage provided in the housing;
an oil cooler provided in the oil passage for cooling the oil;
Equipped with
A refrigerant passage through which a refrigerant passes is connected to the oil cooler,
In the oil cooler, the oil is subjected to heat exchange with the refrigerant ,
The oil cooler is fixed to an outer surface of the gear accommodating portion facing radially outward, and overlaps with at least a portion of the inverter unit when viewed in the axial direction of the motor shaft.
Motor unit. The transmission mechanism includes a gear that overlaps with the inverter unit in the axial direction of the motor shaft.
The motor unit according to claim 1 . At least a portion of the oil cooler is disposed on one side of the gear in a direction perpendicular to both the axial direction and the up-down direction of the motor shaft.
The motor unit according to claim 2. The inverter unit is fixed to the housing at a fixing portion,
The fixing portion is
a visor portion provided on one of the housing and the inverter unit and extending in a horizontal direction;
an opposing surface provided on the other of the housing and the inverter unit and facing the eave portion in a vertical direction;
A fixing bolt;
The eaves portion is provided with a through hole penetrating in the vertical direction,
The opposing surface is provided with a screw hole,
The fixing bolt is screwed into the screw hole on the opposing surface through the through hole of the eaves portion.
The motor unit according to any one of claims 1 to 3 . A motor unit mounted on a vehicle to drive the vehicle,
A motor having a rotor rotatable around a motor shaft and a stator;
a transmission mechanism that transmits the power of the motor and outputs it from an output shaft;
a housing having a motor accommodating portion that accommodates the motor and a gear accommodating portion that accommodates the transmission mechanism;
an inverter unit that supplies power to the motor;
Oil circulating through an oil passage provided in the housing;
an oil cooler provided in the oil passage for cooling the oil;
Equipped with
When viewed in the axial direction of the motor shaft, at least a portion of the inverter unit overlaps with the oil cooler,
The oil cooler is disposed on an outer surface of the housing,
A refrigerant passage through which a refrigerant passes is connected to the oil cooler,
In the oil cooler, the oil is subjected to heat exchange with the refrigerant ,
The inverter unit is fixed to the housing at a fixing portion,
The fixing portion is
a visor portion provided on one of the housing and the inverter unit and extending in a horizontal direction;
an opposing surface provided on the other of the housing and the inverter unit and facing the eave portion in a vertical direction;
A fixing bolt;
The eaves portion is provided with a through hole penetrating in the vertical direction,
The opposing surface is provided with a screw hole,
The fixing bolt is screwed into the screw hole on the opposing surface through the through hole of the eaves portion.
Motor unit. The fixing portion has a first fixing portion and a second fixing portion,
In the first fixing portion, the eave portion is provided on the inverter unit, and the opposing surface is provided on the housing,
In the second fixing portion, the eave portion is provided on the housing, and the opposing surface is provided on the inverter unit.
6. The motor unit according to claim 4 or 5 . The fixing portion has a first fixing portion and a second fixing portion,
When viewed from the axial direction of the motor shaft, the first fixed portion is located on an opposite side to the second fixed portion across the motor shaft.
6. The motor unit according to claim 4 or 5 . The oil cooler is fixed to the gear accommodating portion.
The motor unit according to any one of claims 5 to 7 . The oil cooler is located above the motor shaft.
A motor unit according to any one of claims 1 to 8 . The inverter unit and the oil cooler are connected to each other by a pipe that constitutes the refrigerant path.
The motor unit according to any one of claims 1 to 9 . the inverter unit has a lower surface facing the housing,
The housing faces the lower surface in the up-down direction with a gap therebetween.
A motor unit according to any one of claims 1 to 10 . The motor accommodating portion has a motor chamber therein,
The housing has a flow passage.
The oil passes through the oil cooler and is then supplied to the motor via the flow path at an upper side of the motor chamber.
A motor unit according to any one of claims 1 to 11 .

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