JP7639709B2 - Motor Unit - Google Patents

Description

The present invention relates to a motor unit.
This application claims priority based on Japanese Patent Application No. 2020-003243, filed in Japan on January 10, 2020, the contents of which are incorporated herein by reference.

JP 2016-73163 A discloses a structure in which a refrigerant is cooled by a cooling device provided outside the rotating electric machine and the refrigerant is supplied to a motor by a pump provided outside the rotating electric machine.

International Publication No. 2013/069744

However, if the pump and cooling device are placed outside the rotating electric machine, the rotating electric machine will become large and installation may become difficult.

Therefore, the present invention aims to provide a motor unit that can be made smaller overall while maintaining cooling efficiency.

An exemplary motor unit of the present invention includes a motor having a motor shaft that rotates around a motor axis extending along a horizontal direction, a gear section connected to the motor shaft on one side of the motor axial direction along the motor shaft, a housing that accommodates the motor and the gear section, and a pump that circulates oil accommodated within the housing, wherein the housing includes a motor accommodating section that accommodates the motor, and a gear section accommodating section that is positioned on one side of the motor axial direction of the motor accommodating section and accommodates the gear section, and the pump is attached to the outer surface of one side of the motor axial direction of the gear section, and at least a portion of the pump overlaps with the housing in the motor axial direction.

The exemplary motor unit of the present invention makes it possible to reduce the overall size while maintaining cooling efficiency.

FIG. 1 is a schematic diagram of a vehicle equipped with a motor unit according to an embodiment. FIG. 2 is a conceptual diagram of a motor unit according to one embodiment. FIG. 3 is a perspective view of one side of the motor unit in the motor axial direction as viewed from above. FIG. 4 is a perspective view of the other side of the motor unit in the motor axial direction as viewed from above. FIG. 5 is a perspective view of the motor unit as viewed from below on the other side in the motor axial direction. FIG. 6 is a side view of the motor unit as viewed from one side in the motor axial direction. FIG. 7 is a front view of the motor unit. FIG. 8 is a cross-sectional view of the motor housing taken along a plane perpendicular to the motor shaft.

A motor unit according to an embodiment of the present invention will now be described with reference to the drawings. Note that the scope of the present invention is not limited to the following embodiments, and can be modified as desired within the scope of the technical concept of the present invention. Figure 1 is a schematic diagram of a vehicle Cb equipped with a motor unit 1 according to an exemplary embodiment of the present invention. In Figure 1, the driving direction Dd of the vehicle Cb is indicated by an arrow. The vehicle Cb is a so-called FF type vehicle in which the motor unit 1 is arranged on the front side and drives the front wheels Tf.

In the following explanation, the direction of gravity is defined based on the positional relationship when the motor unit 1 is mounted on a vehicle Cb located on a horizontal road surface. In addition, in the drawings, the XYZ coordinate system is shown as a three-dimensional Cartesian coordinate system as appropriate. That is, in the following explanation, the XYZ coordinate system is based on the state in Figure 1. More specifically, it is defined as follows.

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 (the direction of gravity). The X-axis direction is perpendicular to the Z-axis direction and indicates the front-to-rear direction of the vehicle Cb on which the motor unit 1 is mounted. The +X direction is the front of the vehicle Cb, and the -X direction is the rear of the vehicle Cb. However, it is also possible that the +X direction is the rear of the vehicle Cb and the -X direction is the front of the vehicle Cb. The Y-axis direction is perpendicular to both the X-axis direction and the Z-axis direction and indicates the width direction (left-right direction) of the vehicle. The +Y direction is the left side of the vehicle Cb, and the -Y direction is the right side of the vehicle Cb. However, if the +X direction is the rear of the vehicle Cb, it is also possible that the +Y direction is the right side of the vehicle Cb and the -Y direction is the left side of the vehicle Cb.

The drive system of the vehicle Cb is not limited to the FF system, and may be an FR system in which the motor unit 1 is arranged on the front side and drives the rear wheels Tr. It may be an RR system in which the motor unit 1 is arranged on the rear side of the vehicle Cb and drives the rear wheels Tr. It may also be a four-wheel drive system in which the motor units 1 are arranged on both the front and rear sides and drive the front wheels Tf and the rear wheels Tr. Other systems may also be adopted. The method of mounting the motor unit 1 on the vehicle Cb may differ depending on the drive system. For example, the X-axis direction may be the width direction (left and right direction) of the vehicle Cb, and the Y-axis direction may be the front-rear direction of the vehicle Cb.

In the following description, unless otherwise specified, the direction parallel to the motor axis J2 of the motor 2 (Y-axis direction) is simply referred to as the "axial direction", the radial direction perpendicular to the motor axis J2 is simply referred to as the "radial direction", and the circumferential direction centered on the motor axis J2 is simply referred to as the "circumferential direction". Furthermore, the above-mentioned "parallel direction" includes not only completely parallel directions, but also approximately parallel directions.

The motor unit 1 is mounted on the front of the vehicle Cb as a power source for the drive wheels of the vehicle Cb. In this embodiment, the vehicle Cb is an electric vehicle (EV), but is not limited to this. Examples of the vehicle Cb on which the motor unit 1 is mounted include hybrid vehicles (HVs), plug-in hybrid vehicles (PHVs), and other vehicles in which at least one of the power sources for the drive wheels is a motor.

As shown in Figure 1, the vehicle Cb drives the front wheels Tf with a motor unit 1 disposed at the front side. An output shaft 33 protrudes from both sides of the motor unit 1 in the Y direction. A drive shaft Sd is connected to the end of the output shaft 33 via a joint Cp. The front wheels Tf are connected to the drive shaft Sd.

In the motor unit 1, the torque output from the motor 2 is output to the outside from the output shaft 33. The torque from the output shaft 33 is transmitted to the drive shaft Sd via the joint Cp. This causes the front wheels Tf to rotate, and the vehicle Cb travels on the road surface. Note that the joint Cp can be, for example, a universal joint, but is not limited to this.

<1. Motor unit 1>
Hereinafter, a motor unit 1 according to an exemplary embodiment of the present invention will be described with reference to the drawings. FIG. 2 is a conceptual diagram of the motor unit 1 according to an embodiment. FIG. 3 is a perspective view of one side of the motor unit 1 in the motor axis J2 direction as viewed from above. FIG. 4 is a perspective view of the other side of the motor unit 1 in the motor axis J2 direction as viewed from above. FIG. 5 is a perspective view of the other side of the motor unit 1 in the motor axis J2 direction as viewed from below. FIG. 6 is a side view of the motor unit 1 as viewed from one side in the motor axis J2 direction. FIG. 7 is a front view of the motor unit 1. FIG. 8 is a cross-sectional view cut along a plane perpendicular to the motor axis J2 of the motor housing portion 51. Note that FIG. 2 is a conceptual diagram, and the arrangement and dimensions of each part may not be the same as those of the actual motor unit 1.

As shown in Figure 2, the motor unit 1 has a motor 2, a gear unit 3, a pump 4, a housing 5, and an inverter unit 6. That is, the motor unit 1 has a motor 2, a gear unit 3, and a housing 5.

<2. Motor 2>
2, the motor 2 has a rotor 21 that rotates about a motor axis J2 that extends in the horizontal direction, and a stator 24 that is located radially outward of the rotor 21. The motor 2 is accommodated in a motor accommodating portion 51 of the housing 5, which will be described later.

<2.1 Rotor 21>
The rotor 21 rotates when power is supplied from a battery (not shown) to the stator 24. The rotor 21 has a motor shaft 22, a rotor core 23, and a rotor magnet (not shown). The rotor 21 rotates about a motor axis J2 extending in the horizontal direction.

The motor shaft 22 extends around the motor axis J2 that extends horizontally and in the width direction of the vehicle Cb. That is, the motor 2 has the motor shaft 22 that rotates around the motor axis J2 that extends along the horizontal direction. The motor shaft 22 rotates around the motor axis J2. The motor shaft 22 is a hollow shaft that has a hollow portion 220 therein that has an inner circumferential surface that extends along the motor axis J2.

The motor shaft 22 extends across the motor accommodating section 51 and the gear section accommodating section 52 of the housing 5. One end (+Y side) of the motor shaft 22 protrudes towards the gear section accommodating section 52. A first gear 311 (described later) of the gear section 3 is fixed to the end of the motor shaft 22 protruding into the gear section accommodating section 52. The motor shaft 22 is rotatably supported by a first motor bearing 281 arranged on the bottom 512 of the housing 5 and a second motor bearing 282 arranged on the partition wall section 513 (described later).

The portion of the motor shaft 22 that is disposed in the gear portion accommodating portion 52 is rotatably supported by the second motor bearing 282 and the first gear bearing 341. As described above, the second motor bearing 282 is disposed in the partition wall portion 513. The first gear bearing 341 is disposed in the gear portion accommodating portion 52 of the housing 5, which will be described later. The motor shaft 22 may be split into a portion within the motor accommodating portion 51 and a portion within the gear portion accommodating portion 52. If the motor shaft 22 is split, the split motor shaft 22 may employ, for example, a screw coupling using male and female threads. The split portions may also be joined by a fixing method such as welding.

The rotor core 23 is formed by laminating silicon steel plates. The rotor core 23 is a cylindrical body extending along the axial direction. Multiple rotor magnets are fixed to the rotor core 23. The multiple rotor magnets are arranged along the circumferential direction with alternating magnetic poles.

<2.2 Stator 24>
The stator 24 surrounds the rotor 21 from the radially outer side. That is, the motor 2 is an inner rotor type motor in which the rotor 21 is rotatably disposed inside the stator 24. The stator 24 has a stator core 25, a coil 26, and an insulator (not shown) interposed between the stator core 25 and the coil 26. The stator 24 is held in the housing 5. The stator core 25 has a plurality of magnetic pole teeth extending radially inward from the inner circumferential surface of the annular yoke.

The coil 26 is formed by winding a conductor between the magnetic pole teeth. The conductor is connected to the inverter unit 6 via a bus bar (not shown).

<3. Gear section 3>
The gear unit 3 transmits the torque output from the motor 2 to the drive shaft Sd to which the front wheels Tf are connected. As shown in Fig. 2, the gear unit 3 is accommodated in a gear unit accommodating portion 52 of the housing 5. The gear unit 3 is connected to the motor shaft 22 on one axial side (+Y direction side). That is, the gear unit 3 is connected to the motor shaft 22 on one axial side (+Y direction side) along the motor axis J2. The gear unit 3 has a reduction unit 31 and a differential unit 32.

<3.1 Reduction section 31>
2 and 5, the speed reducer 31 is connected to the motor shaft 22. The speed reducer 31 has a function of reducing the rotational speed of the motor 2 and increasing the torque output from the motor 2 in accordance with a reduction ratio. The speed reducer 31 transmits the torque output from the motor 2 to the differential unit 32.

The reduction gear unit 31 is a parallel shaft gear type reducer in which the axes of the gears are arranged in parallel. The reduction gear unit 31 has a first gear 311 which is an intermediate drive gear, a second gear 312 which is an intermediate gear, a third gear 313 which is a final drive gear, and an intermediate shaft 314.

The first gear 311 is disposed on the outer peripheral surface of the motor shaft 22. The first gear 311 may be the same member as the motor shaft 22, or may be a separate member that is firmly fixed. The first gear 311 rotates together with the motor shaft 22 about the motor axis J2.

The intermediate shaft 314 extends along an intermediate axis J4 parallel to the motor shaft J2. Both ends of the intermediate shaft 314 are rotatably supported by a second gear bearing 342 disposed in the partition wall 513 and a third gear bearing 343 disposed in a cover bottom portion 525 (described later) of the gear portion cover portion 522.

The intermediate shaft 314 is supported in the housing 5 so as to be rotatable about the intermediate axis J4. The second gear 312 and the third gear 313 are arranged on the outer circumferential surface of the intermediate shaft 314. In other words, the second gear 312 and the third gear 313 are connected via the intermediate shaft 314. The second gear 312 may be the same member as the intermediate shaft 314, or may be a separate member that is firmly fixed. The third gear 313 is similar to the second gear 312.

The second gear 312 and the third gear 313 rotate around the intermediate shaft J4. The second gear 312 meshes with the first gear 311. The third gear 313 meshes with the ring gear 321 of the differential portion 32.

The torque of the motor shaft 22 is transmitted from the first gear 311 to the second gear 312. The torque transmitted to the second gear 312 is then transmitted to the third gear 313 via the intermediate shaft 314. The torque transmitted to the third gear 313 is further transmitted to the ring gear 321 of the differential unit 32. In this way, the reduction gear unit 31 transmits the torque output from the motor 2 to the differential unit 32. The gear ratio of each gear and the number of gears can be changed in various ways depending on the required reduction gear ratio.

<3.2 Differential section 32>
The differential part 32 transmits the torque output from the motor 2 to the output shaft 33. The output shafts 33 are attached to the left and right sides of the differential part 32. As shown in Fig. 1, the output shaft 33 is coupled to the drive shaft Sd via a joint Cp.

The differential part 32 has a function of transmitting the same torque to the left and right output shafts 33 while absorbing the speed difference between the left and right front wheels Tf, i.e., the output shafts 33, when the vehicle Cb turns, for example. The differential part 32 has a ring gear 321, a gear housing (not shown), a pair of pinion gears (not shown), a pinion shaft (not shown), and a pair of side gears (not shown).

Also, as shown in Figures 5, 7, etc., the end of the output shaft 33 on the other axial side (-Y direction side) protrudes further than the end of the motor accommodating portion 51 of the housing 5 on the other axial side (-Y direction side).

In the gear unit 3 of this embodiment, the output shaft 33 protrudes on both sides in the Y direction, but is not limited to this. For example, depending on the mounting method of the motor unit 1, the output shaft 33 can protrude only on one side in the Y direction, and a pair of motor units 1 can each drive one wheel. In this case, the differential unit can be omitted.

3.3 Parking mechanism
For example, an electric vehicle does not have a braking mechanism for applying the brakes to the vehicle Cb other than the handbrake. Therefore, a parking mechanism for locking the vehicle Cb when a shift lever (not shown) is moved to the parking position may be attached to the motor unit 1. If the vehicle Cb is an HV, PHV, or the like and has an internal combustion engine and a transmission, the parking mechanism can be omitted.

<4. Inverter unit 6>
The inverter unit 6 is electrically connected to the motor 2. The inverter unit 6 controls the power supplied to the motor 2. As shown in Fig. 2, the inverter unit 6 is accommodated in an inverter accommodating portion 53 of the housing 5. The housing 5 further has an inverter accommodating portion 53 that accommodates the inverter unit 6 that supplies power to the motor 2.

As shown in Figure 2, a refrigerant is supplied to the inverter unit 6 from a radiator (not shown). As shown in Figure 2, an inverter cooling channel 71 for flowing the refrigerant is arranged in the housing lid portion 531 that covers the opening of the inverter housing portion 53. The refrigerant from the radiator flows into the inverter cooling channel 71 through the refrigerant piping 72. As the refrigerant passes through the inverter cooling channel 71, heat generated in the inverter unit 6 is transferred to the refrigerant. In other words, the inverter unit 6 is cooled.

<5. Pump 4>
The pump 4 circulates the oil CL in the internal space of the housing 5. That is, the pump 4 circulates the oil CL contained in the housing 5. The oil CL circulated by the pump 4 is supplied to the motor 2. The motor 2 is cooled by the oil CL. The pump 4 is an electric pump.

3, 7, etc., the pump 4 is attached to the outer surface of one axial side (+Y direction side) of a cover flange portion 526 (described later) of the gear portion accommodating portion 52 of the housing 5. The pump 4 circulates oil CL for cooling the motor 2 and the gear portion 3 inside the housing 5.

The pump 4 has a pump motor and a compression section, both of which are not shown. The compression section has a suction port and a discharge port. The compression section can be, for example, a trochoidal pump in which an external gear and an internal gear, not shown, mesh and rotate, but is not limited to this. For example, the compression section may be a pump other than a trochoidal pump, such as a centrifugal pump. The pump motor drives the compression section. Driven by the pump motor, the compression section draws in oil CL from the oil reservoir 54 through the suction port, compresses it, and discharges it from the discharge port.

As shown in FIG. 7, the suction port of the pump 4 is connected to the oil storage section 54 via the suction pipe 500. The suction pipe 500 is tubular and arranged inside the housing 5. One end of the suction pipe 500 is connected to the oil storage section 54. By driving the pump 4, the oil CL stored inside the oil storage section 54 is sucked in through the suction pipe 500. The oil CL sucked in through the suction pipe 500 is sucked into the inside of the pump 4 through the suction port of the pump 4. That is, the suction port that sucks in the oil of the pump 4 is connected to the suction pipe 500 that is connected to the internal space of the oil storage section 54. The suction pipe 500 may be tubular and arranged inside the housing 5, or may be formed from a separately prepared pipe.

The discharge port of the pump 4 is connected to the flow piping section 561 (described later) of the oil piping section 56. The oil CL discharged from the discharge port of the pump 4 flows into the oil cooler 8 via the flow piping section 561.

By configuring in this manner, it is possible to circulate oil CL inside the motor accommodating space 501.

<6. Oil cooler 8>
The oil cooler 8 is supplied with oil CL and a refrigerant that is supplied via a route separate from the oil CL. The oil cooler 8 has an oil flow pipe section and a refrigerant flow pipe section, both of which are not shown. The oil flow pipe section and the refrigerant flow pipe section are separated by a material with high thermal conductivity, such as aluminum or copper, and heat is exchanged between the oil and the refrigerant.

One end of the oil flow pipe section of the oil cooler 8 is connected to the discharge port of the pump 4 via the flow pipe section 561 of the oil piping section 56. As a result, the oil CL discharged from the pump 4 flows into the oil flow pipe section of the oil cooler 8 via the flow pipe section 561. The other end of the oil flow pipe section of the oil cooler 8 is connected to the supply pipe section 562 of the oil piping section 56, which will be described later. The cooled oil CL flowing out of the oil cooler 8 is sent to the oil scattering section 57, which will be described later, via the supply pipe section 562. In other words, the oil cooler 8 that cools the oil CL passing through the oil piping section 56 is arranged in the path of the oil piping section 56.

As described above, the refrigerant that exchanges heat with the oil CL flows into the refrigerant flow pipe of the oil cooler 8. Here, the piping through which the refrigerant flows will be explained. In the motor unit 1 of this embodiment, the refrigerant that exchanges heat with the oil CL in the oil cooler 8 flows into the oil cooler 8 after being used to cool the inverter unit 6.

The inverter cooling flow path 71 and the oil cooler 8 are connected via a connecting pipe 73. The refrigerant flowing out of the inverter cooling flow path 71 flows into the refrigerant flow pipe section of the oil cooler 8 via the connecting pipe 73. The oil CL flows inside the oil flow pipe section and the refrigerant flows into the refrigerant flow pipe section. At this time, the heat of the oil CL is transferred to the refrigerant, and the oil CL is cooled.

The outflow section of the refrigerant flow pipe of the oil cooler 8 is connected to the radiator via the return pipe 74. The refrigerant that has exchanged heat with the oil CL in the oil cooler 8 returns to the radiator through the return pipe 74. The refrigerant is then cooled by dissipating heat to the outside in the radiator. Note that in this embodiment, the oil CL is cooled by the refrigerant that cooled the inverter unit 6, but this is not limited to this. For example, a pipe may be provided that receives the refrigerant directly from the radiator and returns it.

<7. Housing 5>
As shown in Figure 2 etc., the housing 5 has a motor accommodating section 51, a gear section accommodating section 52, an inverter accommodating section 53, an oil storage section 54 (see Figures 4 and 5), an output shaft support section 55, an oil piping section 56 (see Figure 7), an oil dispersion section 57 (see Figure 8), and a rib 58 (see Figure 5).

The gear housing 52 is located on one axial side (+Y direction side) of the motor housing 51. The motor housing 51 and the gear housing 52 are formed of a metal such as, but not limited to, iron, aluminum, or an alloy thereof.

As shown in FIG. 2, the housing 5 has a motor accommodating space 501 and a gear portion accommodating space 502. The motor accommodating space 501 is the space inside the motor accommodating section 51. The motor 2 is accommodated in the motor accommodating space 501. The gear portion accommodating space 502 is the space inside the gear portion accommodating section 52. The gear portion accommodating space 502 accommodates the gear portion 3. In other words, the housing 5 accommodates the motor 2 and the gear portion 3.

<7.1 Motor accommodating section 51>
The motor accommodating portion 51 has a cylindrical portion 511 and a bottom portion 512. The cylindrical portion 511 is open on one axial side (+Y direction side) and extends in the axial direction. The bottom portion 512 expands radially inward from an end portion on the other axial side (-Y direction side) of the cylindrical portion 511. The bottom portion 512 closes the end portion on the other axial side (-Y direction side) of the cylindrical portion 511. In the motor accommodating portion 51, the cylindrical portion 511 and the bottom portion 512 are formed from the same material. As a result, the motor accommodating portion 51 is cylindrical with a bottom.

Because the motor housing 51 is a bottomed cylinder that opens on the gear housing 52 side, the motor unit 1 can be assembled simply by working from one axial side (the +Y direction side). This eliminates the need to change the position of the worker or the position of the housing 5, making it possible to reduce the number of labor hours required. This makes it possible to reduce the cost of the work.

<7.2 Oil reservoir 54>
An oil reservoir 54 protruding radially outward is disposed below (on the -Z direction side) the motor accommodating portion 51. The motor accommodating portion 51 and the oil reservoir 54 are formed of the same material, and the peripheral wall of the oil reservoir 54 protrudes radially outward, continuing from the peripheral wall of the motor accommodating portion 51. The oil reservoir 54 extends in the axial direction, and the inside of the oil reservoir 54 is connected to the motor accommodating space 501 of the motor accommodating portion 51 (see FIG. 8). The oil CL in the motor accommodating space 501 flows downward and is stored in the oil reservoir 54. That is, the housing 5 further includes an oil reservoir that bulges radially outward from the vertical lower portion of the motor accommodating portion 51 and stores the oil CL.

In this embodiment, the motor housing 51 and the oil storage section 54 are formed from the same material, but are not limited to this. For example, a notch extending in the axial direction (Y direction) may be formed below the motor housing section 51, and the notch may be covered with a separately prepared oil storage section 54. The oil storage section 54 is also arch-shaped with a smaller radius of curvature than the motor housing section 51, but is not limited to this. For example, it may be a shape that combines flat surfaces. A wide variety of shapes can be adopted that can store the oil that circulates through the motor housing section 51 and flows downward.

As shown in Fig. 8, cooling pipe sections 541, 542 may be provided adjacent to the oil reservoir 54 and through which a refrigerant flows. That is, the housing 5 further has cooling pipe sections 541, 542 through which a refrigerant flows to cool the oil CL stored in the oil reservoir 54.

The cooling pipe section 541 is formed inside the wall of the oil reservoir section 54 and is tubular extending in the axial direction (Y direction). The inside side of the cooling pipe section 541 inside the oil reservoir section 54 protrudes inward. This increases the area of the inner surface that comes into contact with the oil CL, improving the heat exchange efficiency, i.e., the cooling efficiency.

The cooling pipe section 542 is a cylinder disposed inside the oil storage section 54. By using such a cooling pipe section 542, the oil CL stored in the oil storage section 54 can be efficiently cooled. The cooling pipe section 542 is disposed inside the housing 5, but is disposed in the space inside the oil storage section 54, so is unlikely to interfere with the motor 2. Note that the housing 5 shown in FIG. 8 employs both the cooling pipe section 541 and the cooling pipe section 542, but either one may be employed.

The refrigerant supplied to the cooling pipes 541, 542 may be, for example, a refrigerant that has cooled other components such as the inverter unit 6, or may be supplied directly from the radiator. A configuration for heating the refrigerant may be provided, and the oil CL stored in the oil storage section 54 may be heated during a cold start. In this way, the oil can be made to have an appropriate viscosity immediately after a cold start. This allows the motor 2 and gear section 3 to be lubricated immediately after a cold start, making it possible to extend the life of the motor unit 1.

<7.3 Partition wall portion 513>
The cylinder portion 511 and the oil reservoir 54 open to one axial side (the +Y direction side). The partition wall 513 closes the openings of the cylinder portion 511 and the oil reservoir 54. The partition wall 513 is detachable from the motor accommodating portion 51 and the oil reservoir 54.

The motor 2 is accommodated in a motor accommodation space 501 surrounded by a cylindrical portion 511, a bottom portion 512, and a partition portion 513. A first motor bearing 281 is disposed in the bottom portion 512. The end portion of the motor shaft 22 on the other axial side (-Y direction side) is rotatably supported by the first motor bearing 281.

A through hole 514 is formed in the partition portion 513. The through hole 514 passes through the partition portion 513 in the axial direction. The center of the through hole 514 coincides with the motor axis J2. A second motor bearing 282 is disposed in the through hole 514. The motor shaft 22 passes through the through hole 514. At this time, the middle portion of the motor shaft 22 in the Y direction is rotatably supported by the second motor bearing 282. In other words, the motor shaft 22 is rotatably supported by the through hole 514 via the second motor bearing 282.

A second gear bearing 342 is disposed below (in the -Z direction) the through hole 514 on one axial side (the +Y direction side) of the partition wall portion 513. The second gear bearing 342 rotatably supports the end of the intermediate shaft 314 on the other axial side (the -Y direction side).

An oil flow hole 515 is formed in the partition wall 513. The oil flow hole 515 is a through hole that penetrates the partition wall 513 in the axial direction. The oil flow hole 515 connects the oil storage section 54 and the gear portion accommodating section 52. A portion of the oil CL that has accumulated in the oil storage section 54 flows into the gear portion accommodating space 502 of the gear portion accommodating section 52 through the oil flow hole 515. By forming the oil flow hole 515 at a position at a certain height from the bottom of the oil storage section 54, the oil CL can be left in the oil storage section 54.

<7.4 Gear portion accommodation portion 52>
The gear portion 3 is accommodated in the gear portion accommodating portion 52. That is, the housing 5 has the gear portion accommodating portion 52 that accommodates the gear portion 3. The gear portion accommodating portion 52 is disposed on one axial side (+Y direction side) of the motor accommodating portion 51. That is, the housing 5 has the gear portion accommodating portion 52 that is disposed on one axial side (+Y direction side) of the motor accommodating portion 51 and accommodates the gear portion 3.

The gear accommodating portion 52 has a gear support portion 521 and a gear cover portion 522. The gear support portion 521 extends radially outward from the outer surface of an end portion on one axial side (+Y direction side) of the tubular portion 511 of the motor accommodating portion 51. The gear support portion 521 is formed of the same material as the tubular portion 511. In other words, the gear accommodating portion 52 has the gear support portion 521 that extends radially outward from the outer surface of an end portion on one axial side (+Y direction side) of the motor accommodating portion 511.

A first output shaft through hole 523 is formed in the gear unit support portion 521. The output shaft 33 passes through the first output shaft through hole 523. As a result, the output shaft 33 passes through the gear unit support portion 521 and extends to the other axial side (-Y direction side). The output shaft 33 is aligned with the motor accommodating portion 51. In other words, the gear unit 3 has an output shaft 33 that passes through the gear unit support portion 521 and extends to the other axial side (-Y direction side).

The other axial end (-Y direction) of the output shaft 33 is rotatably supported by the output shaft support part 55. Details of the output shaft support part 55 will be described later. An oil seal (not shown) is provided between the output shaft 33 and the first output shaft through hole 523 to prevent leakage of oil CL.

The gear cover portion 522 has a cover tube portion 524, a cover bottom portion 525, and a cover flange portion 526. The cover tube portion 524 is cylindrical and open on the other axial side (-Y direction side). The cover bottom portion 525 extends radially inward from the end portion on one axial side (+Y direction side) of the cover tube portion 524. The cover tube portion 524, the cover bottom portion 525, and the cover flange portion 526 are formed from the same material. In other words, the gear cover portion 522 is cylindrical and has a bottom, and is open on the other axial side (-Y direction side).

The cover flange portion 526 protrudes radially outward from the other axial side (-Y direction side) of the cover tube portion 524. When viewed in the axial direction, the cover flange portion 526 overlaps with the gear portion support portion 521. The gear portion support portion 521 and the cover flange portion 526 are overlapped in the axial direction. Then, the peripheral portion of the cover flange portion 526 is fixed to the peripheral portion of the gear portion support portion 521, whereby the gear portion cover portion 522 is attached to the gear portion support portion 521.

The first gear bearing 341 and the third gear bearing 343 are attached to the cover bottom 525. The end of the motor shaft 22 on one axial side (+Y direction side) is rotatably supported by the first gear bearing 341. The end of the intermediate shaft 314 on one axial side (+Y direction side) is rotatably supported by the third gear bearing 343. In other words, the motor shaft 22 is rotatably supported by the housing 5 via the first motor bearing 281, the second motor bearing 282, and the first gear bearing 341. The intermediate shaft 314 is rotatably supported by the housing 5 via the second gear bearing 342 and the third gear bearing 343.

In addition, a second output shaft passing hole 527 is formed in the cover tube portion 524. The output shaft 33 passes through the second output shaft passing hole 527. As a result, the output shaft 33 passes through the cover tube portion 524 and extends to one axial side (+Y direction side). An oil seal (not shown) is provided between the output shaft 33 and the second output shaft passing hole 527 to prevent leakage of oil CL.

In the gear portion housing portion 52, the first output shaft through hole 523 and the second output shaft through hole 527 overlap when viewed in the axial direction. The portion of the output shaft 33 on the other axial side (-Y direction side) of the differential portion 32 passes through the first output shaft through hole 523, and the portion on one axial side (+Y direction side) passes through the second output shaft through hole 527. The output shafts 33, which are arranged at both ends of the differential portion 32 in the axial direction (Y direction), rotate around the output axis J5.

<7.5 Inverter accommodating section 53>
As shown in Figures 3, 4, 8, etc., the inverter accommodating portion 53 is disposed above the motor accommodating portion 51 on the -X direction side. The inverter accommodating portion 53 is formed of the same material as the motor accommodating portion 51. That is, the inverter accommodating portion is formed of the same material as the motor accommodating portion 51. The inverter accommodating portion 53 is open at the top. An accommodating lid portion 531 is attached to the opening of the inverter accommodating portion 53. The inverter unit 6 is accommodated in the space surrounded by the inverter accommodating portion 53 and the accommodating lid portion 531.

The storage lid 531 is fixed to the inverter storage section 53 by a fixing method such as screwing. As a result, the opening of the inverter storage section 53 is closed by the storage lid 531. The fixing of the storage lid 531 to the inverter storage section 53 is not limited to screwing, and a wide variety of fixing methods can be used that are both strong and detachable.

The butt joint between the inverter accommodating section 53 and the accommodating lid section 531 has a configuration that suppresses the intrusion of moisture. This makes it difficult for moisture to adhere to the inverter unit 6 accommodated inside the inverter accommodating section 53. Note that an example of a configuration that suppresses the intrusion of moisture at the butt joint between the inverter accommodating section 53 and the accommodating lid section 531 may include, but is not limited to, a configuration in which a gasket, packing, or the like is disposed between the inverter accommodating section 53 and the accommodating lid section 531.

The internal space of the inverter accommodating section 53 and the motor accommodating space 501 of the motor accommodating section 51 are connected by a wiring hole 532. Wiring connecting the inverter unit 6 and the coil 26 of the motor 2 is arranged in the wiring hole 532. By providing such a wiring hole 532, it is possible to reduce openings through which moisture can enter the internal space of the inverter accommodating section 53. The wiring hole 532 is provided with a seal (not shown) that suppresses the infiltration of oil CL circulating in the motor accommodating space 501.

3, 4, 5, 8, etc., the storage lid portion 531 has an inverter cooling channel 71. A refrigerant passes through the inverter cooling channel 71. When the refrigerant passes through the inverter cooling channel 71, heat generated from the inverter unit 6 is transferred to the refrigerant. This cools the inverter unit 6. By cooling the inverter unit 6, it becomes possible for it to operate stably. In the housing 5 of this embodiment, the inverter cooling channel 71 is arranged in the storage lid portion 531. To enhance the cooling effect, the inverter unit 6 may also be attached to the storage lid portion 531. The inverter cooling channel 71 may also be arranged in the inverter storage portion 53. In this case, the inverter unit 6 may be attached to the inverter storage portion 53.

7.6 Output shaft support portion 55
The output shaft support portion 55 protrudes outward from the end portion on the other axial direction side (−Y direction side) of the outer circumferential surface of the motor accommodating portion 51. The output shaft support portion 55 and the motor accommodating portion 51 are formed from the same material.

The output shaft support 55 has a through hole whose center coincides with the output shaft J5, and an output bearing 551 (see Figures 2, 4, and 5) is attached to the through hole. The output shaft support 55 rotatably supports the output shaft 33 via the output bearing 551.

That is, the housing 5 further has an output shaft support portion 55 that rotatably supports the output shaft 33 on the other axial side (-Y direction side) of the motor accommodating portion 51. (0747, claim 1, lines 13 to 14) In addition, the output shaft support portion 55 is formed of the same material as the motor accommodating portion 51.

The output shaft support portion 55 is formed from the same material as the underside of the inverter accommodating portion 53. The output shaft support portion 55 is formed by integral molding together with the inverter accommodating portion 53. This configuration increases the rigidity of the output shaft support portion 55 and suppresses vibration of the output shaft 33.

The output shaft support portion 55 may be formed of a different material than the inverter accommodating portion 53. In this case, the output shaft support portion 55 and the inverter accommodating portion 53 may be in contact with each other. If the output shaft support portion 55 is not formed of the same material as the inverter accommodating portion 53, stress is unlikely to be transmitted from the inverter accommodating portion 53 to the output shaft support portion 55. Therefore, even if stress acts on the inverter accommodating portion 53, deformation of the output shaft support portion 55 is suppressed, and core runout of the output shaft 33 is unlikely to occur.

The output shaft support 55 and the inverter accommodating section 53 may be non-contact. Stress is less likely to be transmitted between the inverter accommodating section 53 and the output shaft support 55, and vibrations and the like can be suppressed. In addition, the output shaft support 55 and the inverter accommodating section 53 may be formed of the same material, and the output shaft support 55 and the motor accommodating section 51 may be formed of different materials. By forming them in this manner, it is possible to suppress resonance between the vibrations of the motor 2 transmitted to the motor accommodating section 51 and the vibrations transmitted to the output shaft support 55.

Since the housing 5 has the output shaft support portion 55, it is possible to extend the output shaft 33 from the gear portion support portion 521 to the other axial side (-Y direction side). As shown in FIG. 1, the drive shaft Sd is connected to the tip of the output shaft 33 via a joint Cp (see FIG. 1).

By adjusting the length of the output shaft 33, the lengths of the drive shafts Sd connected to the left and right front wheels Tf can be made the same when the motor unit 1 is mounted on the vehicle Cb. Making the lengths of the drive shafts Sd the same allows the drive shafts Sd to be connected at the same angle to the output shaft 33. This allows equal torque to be transmitted to the left and right front wheels Tf, allowing the driver to operate the vehicle Cb without any discomfort. In other words, it is possible to improve the operability of the vehicle Cb.

In the motor unit 1, the gear section 3 determines the length of the output shaft 33 so that the left and right drive shafts Sd are equal in length based on the mounting position of the motor unit 1 on the vehicle Cb and the position of the front wheels Tf. And because the housing 5 has an output shaft support section 55, the output shaft 33 can rotate stably even if it is extended in the other axial direction (-Y direction).

In other words, since the housing 5 of the motor unit 1 has the output shaft support portion 55, the output shaft 33 can be extended in the other axial direction (-Y direction). This allows the left and right drive shafts Sd of the vehicle Cb on which the motor unit 1 is mounted to be of equal length, thereby reducing the discomfort felt by the driver while driving. It is preferable that the output shaft support portion 55 supports the vicinity of the end of the output shaft 33.

In addition, in the motor unit 1 of this embodiment, both ends of the output shaft 33 in the Y direction protrude outward beyond the housing 5. Therefore, when the drive shaft Sd is attached via the joint Cp, the joint Cp and the drive shaft Sd are unlikely to interfere with the housing 5.

5, the rib 58 protrudes from the radial outer surface of the tubular portion 511 of the motor accommodating portion 51 and extends radially outward in the axial direction to connect the gear portion support portion 521 and the output shaft support portion 55. That is, the housing 5 further has a plate-shaped rib 58 that protrudes from the radial outer surface of the motor accommodating portion 51 and connects the gear portion support portion 521 and the output shaft support portion 55.

The rib 58 is formed of the same material as the motor accommodating section 51. The rib 58 is also formed of the same material as the gear section support section 521 and the output shaft support section 55. That is, the rib 58 is formed of the same material as the motor accommodating section 51, the gear section support section 521 and the output shaft support section 55. The provision of the rib 58 suppresses deformation of the motor accommodating section 51, the gear section support section 521 and the output shaft support section 55. This suppresses vibration and noise of the motor 2 and the housing 5 themselves caused by driving the gear section 3.

In this embodiment, the width of the rib 58 protruding from the tubular portion 511 narrows from the gear portion support portion 521 side toward the output shaft support portion 55 side. However, this shape is not limited to this, and a wide variety of shapes that can suppress vibration and noise with the rib 58 can be adopted.

<7.7 Oil piping section 56>
2 and 6, the oil piping section 56 is tubular and formed inside the gear portion support section 521 of the gear portion accommodating section 52. The oil piping section 56 is connected to an oil scattering section 57 provided in the upper part of the motor accommodating space 501. The oil piping section 56 connects the pump 4 and the oil scattering section 57, and supplies oil CL to the oil scattering section 57. In other words, the housing 5 has the oil piping section 56 that connects the discharge port from which the pump 4 discharges oil and the oil scattering section 57 provided in the internal space 501 of the motor accommodating section 51.

In addition, the housing 5 of this embodiment has a flow piping section 561 and a supply piping section 562. The flow piping section 561 connects the discharge port of the pump 4 and the inlet of the oil cooler 8. In other words, the oil CL pressurized by the pump 4 is sent from the pump 4 to the oil cooler 8 via the flow piping section 561. In addition, the supply piping section 562 connects the outlet of the oil cooler 8 and a flow passage 571 of the oil dispersion section 57, which will be described later. In other words, the oil CL cooled by the oil cooler 8 is sent from the oil cooler 8 to the oil dispersion section 57 via the supply piping section 562.

In this embodiment, the oil piping section 56 is formed in the cover flange section 526, but is not limited thereto. It may be formed in the gear support section 521, or may be formed by combining and fixing the gear support section 521 and the cover flange section 526.

<7.8 Oil dispersing unit 57>
The oil scattering part 57 is disposed in the motor accommodating part 51. Furthermore, the oil scattering part 57 is disposed vertically above the motor 2. That is, the housing 5 further has the oil scattering part 57 that is disposed vertically above the motor 2 inside the motor accommodating part 51 and is connected to the oil piping part 56.

The oil dispersion section 57 has a flow passage 571 extending in the axial direction (Y direction) through which the oil CL flows, and a dispersion hole 572 connecting the flow passage 571 to the motor accommodating space 501.

The oil CL flowing through the oil piping section 56 flows into the flow passage 571 of the oil scattering section 57. The oil CL that flows into the flow passage 571 is then scattered from the scattering hole 572 into the motor housing space 501. With this configuration, the oil CL can be scattered onto the motor 2 arranged in the motor housing space 501. This allows the motor 2 to be efficiently cooled by the oil CL. In this embodiment, the oil scattering section is tubular and formed inside the motor housing section 51, but is not limited to this. For example, it may be a pipe inserted into the motor housing space 501.

In addition, the oil dispersion unit 57 may be in the form of a container that is open at the top and has a hole for dripping oil at an appropriate location on the bottom instead of being tubular. In this case, the oil CL supplied from the supply pipe 562 flows into the oil dispersion unit 57, and the oil is dripped from the oil dispersion unit 57.

<7.9 Positions of Pump 4 and Oil Cooler 8>
The pump 4 and the oil cooler 8 are attached to one axial side (+Y direction side) of the cover flange portion 526 of the gear portion accommodating portion 52 of the housing 5. More specifically, the pump 4 and the oil cooler 8 are attached to the outside of the gear portion accommodating portion 52. The oil piping portion 56 connects the pump 4 and the oil cooler 8. The oil piping portion 56 also connects the oil cooler 8 and the oil dispersion portion 57.

As shown in Figure 6, the pump 4 and oil cooler 8 are positioned so as to fit within the axial projection of the housing 5. Note that the pump 4 and oil cooler 8 may partly extend outward from the axial projection of the housing 5. That is, the pump 4 is attached to the outer surface of one axial side (+Y direction side) of the gear unit accommodating portion 52, with at least a portion overlapping with the housing 5 in the axial direction. The oil cooler 8 is attached to the outer surface of one axial side (+Y direction side) of the gear unit accommodating portion 52, with at least a portion overlapping with the housing 5 in the axial direction.

With this configuration, the vertical (Z-direction) thickness of the motor unit 1 can be reduced. The motor unit 1 can be made more compact. The pump 4 is exposed to the outside of the motor unit 1. When the vehicle is running, the wind blows against the pump 4. The pump 4 is cooled by the wind while the vehicle is running. In addition, the wind blows against the outer surface of the oil cooler 8 while the vehicle is running. As a result, the oil cooler 8 is also cooled by the wind.

<8. Lubrication and Cooling of Motor Unit 1>
2, an oil sump P in which oil CL accumulates is provided in a lower region within the gear portion accommodating portion 52. A portion of the differential portion 32 is immersed in the oil sump P. The oil CL accumulated in the oil sump P is scooped up by the operation of the differential portion 32 and supplied to the inside of the gear portion accommodating portion 52. That is, when the ring gear 321 of the differential portion 32 rotates, the oil CL is scooped up by the tooth surface of the ring gear 321.

The oil CL diffused in the gear housing 52 is supplied to each gear of the reduction gear unit 31 and the differential unit 32 in the gear housing 52, and the oil CL is spread over the gear tooth surfaces and used for lubrication. In addition, a portion of the oil CL diffused in the gear housing 52 is supplied to each of the second motor bearing 282, the first gear bearing 341, the second gear bearing 342, and the third gear bearing 343, and used for lubrication.

When the motor 2 starts operating from a stopped state, a portion of the ring gear 321 is immersed in the oil CL. Therefore, when the ring gear 321 rotates, the oil CL is scooped upward along the inner circumferential surface of the gear portion housing space 502.

An oil reserve dish 528 is disposed in the gear portion accommodating space 502. The oil reserve dish 528 is open upward. The oil reserve dish 528 is formed across both axial ends of the gear portion accommodating space 502. Oil CL scooped up from the oil reservoir P moves upward in the gear portion accommodating space 502 and flows into the oil reserve dish 528.

One axial end of the oil reserve dish 528 is connected to an oil supply passage (not shown). The oil CL stored in the oil reserve dish 528 flows into the hollow portion 220 of the motor shaft 22 from the end of the motor shaft 22 on one axial side (+Y direction side) via the oil supply passage.

Oil CL flows into the hollow portion 220 of the motor shaft 22. The oil CL in the hollow portion 220 of the motor shaft 22 flows from the end of the motor shaft 22 on one axial side (+Y direction side) and flows toward the motor 2. The inside of the hollow portion 220 of the motor shaft 22 may have a structure, such as a spiral groove, that sends the oil CL to the motor 2 side when the motor shaft 22 rotates. The oil CL that flows through the hollow portion 220 is sprayed toward the stator 24 from the oil spray hole 221 (see FIG. 2) provided in the motor shaft 22. The stator 24 is cooled by the oil CL. In other words, in the motor unit 1, the oil CL in the oil reservoir P in the gear portion accommodation space 502 is scooped up by the gear portion 3, thereby circulating the oil CL inside the motor unit 1.

In addition to being scooped up by the rotation of the gear section 3, the motor unit 1 also circulates the oil CL by the pump 4. When the pump 4 is driven, the oil CL stored in the oil storage section 54 is sucked into the pump 4. The pump 4 draws the oil CL from the suction port and discharges it from the discharge port into the oil cooler 8 via the oil piping section 56. The oil CL is cooled by heat exchange with the refrigerant in the oil cooler 8, and flows into the oil dispersion section 57 via the oil piping section 56. The oil CL then flows through the flow passage 571 of the oil dispersion section 57 and is dispersed into the motor housing space 501 from the dispersion hole 572. The oil CL dispersed from the dispersion hole 572 is sprayed onto the motor 2.

The oil CL sprayed onto the motor 2 flows inside the motor 2. This causes the oil CL to cool the motor 2. After cooling the motor 2, the oil CL flows downwards according to gravity and into the oil reservoir 54 connected below the motor housing 51. In this way, the oil CL can be circulated inside the motor housing space 501 by the pump 4.

A portion of the oil CL scooped up by the gear portion 3 flows into the motor housing space 501 through the hollow portion 220 of the motor shaft 22. The pump 4 also circulates the oil CL in the motor housing space 501 and the space inside the oil reservoir 54. Therefore, the circulated oil CL flows into the oil reservoir 54. The internal space of the oil reservoir 54 and the gear portion housing space 502 are partitioned by a partition 513. An oil flow hole 515 is formed in the partition 513. Therefore, a portion of the oil CL accumulated inside the oil reservoir 54 flows into the gear portion housing space 502. This keeps the amount of oil CL accumulated in the oil reservoir 54 and the oil reservoir P constant.

In this way, in the motor unit 1, the oil CL is circulated within the motor accommodating space 501 and the gear section accommodating space 502 to lubricate and cool the motor 2 and gear section 3.

Although the embodiments of the present invention have been described above, each configuration and their combinations in the embodiments are merely examples, and additions, omissions, substitutions and other modifications of the configurations are possible without departing from the spirit of the present invention. Furthermore, the present invention is not limited to the embodiments.

The motor unit of the present invention can be used, for example, as at least part of the power source for hybrid vehicles (HVs), plug-in hybrid vehicles (PHVs) and electric vehicles (EVs).

REFERENCE SIGNS LIST 1 motor unit 2 motor 21 rotor 22 motor shaft 220 hollow portion 221 oil dispersion hole 23 rotor core 24 stator 25 stator core 26 coil 281 first motor bearing 282 second motor bearing 3 gear portion 31 reduction gear portion 311 first gear 312 second gear 313 third gear 314 intermediate shaft 32 differential portion 321 ring gear 33 output shaft 341 first gear bearing 342 second gear bearing 343 third gear bearing 4 pump 5 housing 500 suction pipe 501 motor housing space 502 gear portion housing space 51 motor housing portion 511 cylindrical portion 512 bottom portion 513 partition portion 514 through hole 515 oil flow hole 52 Gear portion accommodation portion 521 Gear portion support portion 522 Gear portion cover portion 523 First output shaft passing hole 524 Cover cylinder portion 525 Cover bottom portion 526 Cover flange portion 527 Second output shaft passing hole 528 Oil reserve dish 53 Inverter accommodation portion 531 Accommodation lid portion 532 Wiring hole 54 Oil storage portion 541 Cooling pipe portion 542 Cooling pipe portion 55 Output shaft support portion 551 Output bearing 56 Oil piping portion 561 Flow piping portion 562 Supply piping portion 57 Oil spray portion 571 Flow passage 572 Spray hole 58 Rib 6 Inverter unit 71 Inverter cooling flow path 72 Refrigerant piping 73 Connection piping 74 Return piping 8 Oil cooler Cb Vehicle Cp Joint Dd Driving direction Sd Drive shaft Tf Front wheels Tr Rear wheels P Oil reservoir CL Oil

Claims (7)

a motor having a motor shaft that rotates about a motor axis extending along a horizontal direction;
a gear portion connected to the motor shaft at one side in a motor axial direction along the motor shaft;
a housing that accommodates the motor and the gear portion;
a pump for circulating oil contained within the housing;
an oil cooler attached to the housing and configured to cool the oil;
The housing includes:
a motor housing portion that houses the motor;
a gear portion accommodating portion disposed on one side of the motor accommodating portion in the motor axial direction and accommodating the gear portion,
the oil cooler and the pump are attached to an outer surface of the gear portion housing portion on one side in the motor axial direction,
A portion of the oil cooler overlaps with an axial projection plane of the housing,
Another part of the oil cooler protrudes from an axial projection plane of the housing,
The pump and the oil cooler overlap with the motor in the axial direction.
Motor unit. The motor unit according to claim 1, wherein the housing has an oil piping section that connects a discharge port that discharges oil from the pump to an oil spray section provided in the internal space of the motor housing section. the housing further includes an oil reservoir portion that bulges outward in a radial direction of the motor accommodating portion from a vertical lower portion of the motor accommodating portion and that accommodates the oil;
The motor unit according to claim 2 , wherein the pump sucks oil stored in the internal space of the oil reservoir. The motor unit according to claim 3, wherein the housing further has a cooling pipe section through which a refrigerant flows to cool the oil stored in the oil storage section. The oil cooler is disposed in a path of the oil piping section and cools the oil passing through the oil piping section.
The motor unit according to any one of claims 2 to 4. the gear portion accommodating portion has a gear portion support portion that extends radially outward from a radial outer surface of one end of the motor accommodating portion in the motor axial direction and is made of the same material as the motor accommodating portion,
6. The motor unit according to claim 2, wherein the oil piping portion is tubular and formed inside the gear support portion. The housing includes:
The oil supply system further includes a tubular oil distribution section that is disposed vertically above the motor inside the motor housing section and that is connected to the oil piping section,
The oil distribution portion includes a flow passage extending in the motor axial direction and through which the oil flows;
7. The motor unit according to claim 2, further comprising a dispersion hole connecting the flow passage and the motor housing portion.

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