CN212033933U

CN212033933U - Drive device

Info

Publication number: CN212033933U
Application number: CN202020470481.3U
Authority: CN
Inventors: 小山崇宣; 石川勇树
Original assignee: Nidec Corp
Current assignee: Nidec Corp
Priority date: 2019-04-11
Filing date: 2020-04-02
Publication date: 2020-11-27
Anticipated expiration: 2030-04-02
Also published as: JP7318287B2; JP2020174477A

Abstract

The utility model provides a drive device, one of which is a drive device that makes the axletree of vehicle rotate, and this drive device has: a motor; a reduction gear connected to the motor; a differential device connected to the motor via a reduction gear, and configured to rotate the axle about a differential axis; a housing that houses oil therein, the housing having a motor housing portion that houses a motor therein and a gear housing portion that houses a reduction gear and a differential gear therein; and an oil cooler that is located outside the housing and cools oil contained inside the housing. The oil cooler is formed to be long in the axial direction of the differential axis.

Description

Drive device

Technical Field

The utility model relates to a driving device.

Background

A drive device mounted on a vehicle and having oil contained in a casing is known. For example, patent document 1 describes a drive device for a hybrid vehicle.

Patent document 1: international publication No. 2012/046307

In the above-described drive device, the oil contained in the casing is used to cool the drive device. Therefore, the driving device is provided with an oil cooler that cools oil contained in the casing. In such a drive device, further improvement in cooling efficiency is required.

SUMMERY OF THE UTILITY MODEL

In view of the above, an object of the present invention is to provide a drive device having a structure capable of improving cooling efficiency.

The utility model discloses a mode 1 is drive arrangement, and it makes the axletree of vehicle rotate, and this drive arrangement has: a motor; a reduction gear connected to the motor; a differential device connected to the motor via the reduction gear, and configured to rotate the axle about a differential axis; a case that contains oil therein and that has a motor containing portion that contains the motor therein and a gear containing portion that contains the reduction gear and the differential gear therein; and an oil cooler that is located outside the housing and cools oil contained inside the housing. The oil cooler is long in the axial direction of the differential axis.

The feature of the invention according to claim 2 is that, in the invention according to claim 1, the oil cooler is attached to a portion of the motor housing portion which is located on one side of the front-rear direction perpendicular to the two directions of the axial direction and the vertical direction of the differential axis.

The feature of claim 3 is that, in the feature of claim 2, the oil cooler is exposed to one side in the front-rear direction.

The feature of the 4 th aspect of the present invention is that, in the 1 st aspect, the oil cooler is attached to a portion of the motor housing portion located on a lower side in the vertical direction.

The feature of the invention according to claim 5 is that, in the invention according to claim 2, the oil cooler is attached to a portion of the motor housing portion located on a lower side in the vertical direction.

The feature of the 6 th aspect of the present invention is that, in the 3 rd aspect, the oil cooler is attached to a portion of the motor housing portion located on a lower side in the vertical direction.

The feature of the 7 th aspect of the present invention is that, in the 4 th aspect, the oil cooler is exposed at a lower side in the vertical direction.

The feature of claim 8 is that, in the 5 th aspect, the oil cooler is exposed at a lower side in the vertical direction.

The feature of the 9 th aspect of the present invention is that, in the 6 th aspect, the oil cooler is exposed at a lower side in the vertical direction.

The feature of the 10 th aspect of the present invention resides in that, in the 1 st to the 9 th aspects, the motor has a rotor that can rotate about a motor axis extending in a direction parallel to the differential axis, the motor housing portion has a tubular shape surrounding the motor axis, and the oil cooler is mounted on a radially outer side surface of the motor housing portion.

According to the utility model discloses a mode can improve drive arrangement's cooling efficiency.

Drawings

Fig. 1 is a schematic configuration diagram schematically showing a driving device according to the present embodiment.

Fig. 2 is a perspective view of the driving device of the present embodiment as viewed in one direction.

Fig. 3 is a perspective view of the driving device of the present embodiment viewed in another direction.

Fig. 4 is a view of a part of the housing of the present embodiment as viewed from the front side.

Fig. 5 is a view of a part of the driving device of the present embodiment as viewed from the front side.

Fig. 6 is a perspective view showing an oil cooler of the present embodiment.

Fig. 7 is a partial cross-sectional view showing a part of the drive device of the present embodiment, and is a partial cross-sectional view taken along line VII-VII in fig. 5.

Description of the reference symbols

1: a drive device; 2: a motor; 4: a reduction gear; 5: a differential device; 6: a housing; 20: a rotor; 55: an axle; 70: an oil cooler; 81: a motor storage section; 82: a gear housing section; j1: a motor axis; j3: a differential axis; o: and (3) oil.

Detailed Description

In the following description, the vertical direction is defined and described based on the positional relationship when the driving device according to the embodiment shown in each of the drawings is mounted on a vehicle on a horizontal road surface. In the drawings, an XYZ coordinate system is appropriately shown as a three-dimensional rectangular coordinate system. In the XYZ coordinate system, the Z-axis direction is the vertical direction. The + Z side is the upper side in the vertical direction, and the-Z side is the lower side in the vertical direction. In the following description, the vertical upper side is simply referred to as "upper side", and the vertical lower side is simply referred to as "lower side". The X-axis direction is a direction perpendicular to the Z-axis direction, and is a front-rear direction of a vehicle on which the driving device is mounted. In the following embodiments, the + X side is the front side of the vehicle and the-X side is the rear side of the vehicle. The Y-axis direction is a direction perpendicular to both the X-axis direction and the Z-axis direction, and is a vehicle width direction, which is a left-right direction of the vehicle. In the following embodiments, the + Y side is the left side of the vehicle and the-Y side is the right side of the vehicle. The front-back direction and the left-right direction are horizontal directions perpendicular to the vertical direction. In the present embodiment, the front side corresponds to one side in the front-rear direction.

The positional relationship in the front-rear direction is not limited to the positional relationship in the following embodiments, and the + X side may be the rear side of the vehicle and the-X side may be the front side of the vehicle. In this case, the + Y side is the right side of the vehicle and the-Y side is the left side of the vehicle.

The motor axis J1 shown in the drawings as appropriate extends in the Y-axis direction, i.e., the left-right direction of the vehicle. In the following description, unless otherwise specified, a direction parallel to the motor axis J1 is simply referred to as an "axial direction", a radial direction about the motor axis J1 is simply referred to as a "radial direction", and a circumferential direction about the motor axis J1 (i.e., a direction about the motor axis J1) is simply referred to as a "circumferential direction". In the present specification, the "parallel direction" also includes a substantially parallel direction, and the "perpendicular direction" also includes a substantially perpendicular direction.

The drive device 1 of the present embodiment shown in fig. 1 to 3 is mounted on a vehicle having a motor as a power source, such as a Hybrid Electric Vehicle (HEV), a plug-in hybrid electric vehicle (PHV), or an Electric Vehicle (EV), and is used as a power source for these vehicles. As shown in fig. 1, the drive device 1 includes a motor 2, a reduction gear 4, a differential 5, a case 6, an inverter unit 8, an oil cooler 70, and an electric oil pump 96. The housing 6 has: a motor housing section 81 that houses the motor 2 therein; and a gear housing portion 82 that houses the reduction gear 4 and the differential gear 5 therein. The gear housing 82 is located on the left side of the motor housing 81.

In the present embodiment, the motor 2 is an inner rotor type motor. The motor 2 has a rotor 20, a stator 30, and

bearings

26 and 27. The rotor 20 is rotatable about a motor axis J1 extending in the horizontal direction. The rotor 20 has a shaft 21 and a rotor body 24. Although not shown, the rotor body 24 includes a rotor core and a rotor magnet fixed to the rotor core. The torque of the rotor 20 is transmitted to the reduction gear 4.

The shaft 21 extends in the axial direction about the motor axis J1. The shaft 21 rotates about a motor axis J1. The shaft 21 is a hollow shaft having a hollow portion 22 provided therein. A communication hole 23 is provided in the shaft 21. The communication hole 23 extends in the radial direction to connect the hollow portion 22 and the outside of the shaft 21.

The shaft 21 extends across the motor housing 81 and the gear housing 82 of the housing 6. The left end of the shaft 21 protrudes into the gear housing 82. A 1 st gear 41 of the reduction gear 4, which will be described later, is fixed to the left end of the shaft 21. The shaft 21 is rotatably supported by

bearings

26 and 27.

The stator 30 is opposed to the rotor 20 with a gap therebetween in the radial direction. In more detail, the stator 30 is located radially outward of the rotor 20. The stator 30 has a stator core 32 and a coil assembly 33. The stator core 32 is fixed to the inner circumferential surface of the motor housing 81. Although not shown, the stator core 32 includes a cylindrical core back portion extending in the axial direction and a plurality of teeth extending radially inward from the core back portion.

The coil assembly 33 has a plurality of coils 31 attached to the stator core 32 along the circumferential direction. The plurality of coils 31 are attached to the respective teeth of the stator core 32 via insulators not shown. The plurality of coils 31 are arranged along the circumferential direction. More specifically, the plurality of coils 31 are arranged at equal intervals along the circumferential direction over a circumferential range. Although not shown, the coil assembly 33 may include a binding member or the like for binding the coils 31, or may include a crossover for connecting the coils 31 to each other.

The coil assembly 33 has coil ends 33a, 33b projecting from the stator core 32 in the axial direction. The coil end 33a is a portion protruding rightward from the stator core 32. The coil end 33b is a portion protruding leftward from the stator core 32. The coil end 33a includes a portion of each coil 31 included in the coil assembly 33 that protrudes to the right of the stator core 32. The coil end 33b includes a portion of each coil 31 included in the coil assembly 33 that protrudes to the left of the stator core 32. In the present embodiment, the coil ends 33a and 33b are annular around the motor axis J1. Although not shown, the coil ends 33a and 33b may include a binding member or the like for binding the coils 31, or may include a crossover for connecting the coils 31 to each other.

The

bearings

26 and 27 rotatably support the rotor 20. The

bearings

26 and 27 are ball bearings, for example. The bearing 26 is a bearing that rotatably supports a portion of the rotor 20 located on the right side of the stator core 32. In the present embodiment, the bearing 26 supports a portion of the shaft 21 located on the right side of the portion to which the rotor body 24 is fixed. The bearing 26 is held by a wall portion of the motor housing 81 covering the right side of the rotor 20 and the stator 30.

The bearing 27 is a bearing that rotatably supports a portion of the rotor 20 located on the left side of the stator core 32. In the present embodiment, the bearing 27 supports a portion of the shaft 21 located on the left side of the portion to which the rotor body 24 is fixed. The bearing 27 is held by a partition wall 61c described later.

The reduction gear 4 is connected to the motor 2. More specifically, the reduction gear 4 is connected to the left end of the shaft 21. The reduction gear 4 reduces the rotation speed of the motor 2 to increase the torque output from the motor 2 at a reduction ratio. The reduction gear 4 transmits the torque output from the motor 2 to the differential device 5. The reduction gear 4 has a 1 st gear 41, a 2 nd gear 42, a 3 rd gear 43, and an intermediate shaft 45.

The 1 st gear 41 is fixed to the outer peripheral surface of the left end of the shaft 21. The 1 st gear 41 rotates together with the shaft 21 about the motor axis J1. The intermediate shaft 45 extends along an intermediate axis J2. In the present embodiment, the intermediate axis J2 is parallel to the motor axis J1. In the present embodiment, the intermediate axis J2 is located below the motor axis J1. Although not shown, the intermediate axis J2 is located on the rear side (on the (-X) side) of the motor axis J1, for example. The intermediate shaft 45 rotates about the intermediate axis J2.

The 2 nd gear 42 and the 3 rd gear 43 are fixed to the outer peripheral surface of the intermediate shaft 45. The 2 nd gear 42 and the 3 rd gear 43 are connected via an intermediate shaft 45. The 2 nd gear 42 and the 3 rd gear 43 rotate about the intermediate axis J2. The 2 nd gear 42 meshes with the 1 st gear 41. The 3 rd gear 43 meshes with a ring gear 51 of the differential device 5, which will be described later. The outer diameter of the 2 nd gear 42 is larger than that of the 3 rd gear 43. In the present embodiment, the lower end of the 2 nd gear 42 is the lowest part of the reduction gear 4.

The torque output from the motor 2 is transmitted to the differential device 5 via the reduction gear 4. More specifically, the torque output from the motor 2 is transmitted to the ring gear 51 of the differential device 5 via the shaft 21, the 1 st gear 41, the 2 nd gear 42, the intermediate shaft 45, and the 3 rd gear 43 in this order. The gear ratio of each gear, the number of gears, and the like can be variously changed according to a required reduction ratio. In the present embodiment, the reduction gear 4 is a parallel-axis gear type reduction gear in which the axes of the gears are arranged in parallel.

The differential device 5 is connected to the reduction gear 4. Thereby, the differential device 5 is connected to the motor 2 via the reduction gear 4. The differential device 5 is a device for transmitting the torque output from the motor 2 to the wheels of the vehicle. The differential device 5 absorbs a speed difference between the left and right wheels when the vehicle turns, and transmits the same torque to the axles 55 of the left and right wheels. The differential device 5 rotates the axle 55 about the differential axis J3. Thereby, the drive device 1 rotates the axle 55 of the vehicle.

In the present embodiment, the differential axis J3 is parallel to the motor axis J1. That is, in the present embodiment, the motor axis J1 extends in a direction parallel to the differential axis J3. The front-rear direction is a direction perpendicular to both the axial direction and the vertical direction of the differential axis J3. As shown in fig. 2, in the present embodiment, the differential axis J3 is located on the rear side (-X side) of the motor axis J1. The differential axis J3 is located on the lower side of the motor axis J1. Although not shown, the differential axis J3 is located rearward of the intermediate axis J2. In fig. 1, the differential axis J3 is schematically shown below the intermediate axis J2, but the differential axis J3 is located substantially at the same position as the intermediate axis J2 in the vertical direction, for example. The differential axis J3 is located slightly above the intermediate axis J2, for example.

Although not shown, the differential device 5 is located on the rear side (-X side) of the reduction gear unit 4 inside the gear housing 82. As shown in fig. 1, the differential device 5 includes a ring gear 51, a gear housing, a pair of pinion gears, a pinion shaft, and a pair of side gears. The ring gear 51 is a gear that rotates about the differential axis J3. The ring gear 51 meshes with the 3 rd gear 43. Thereby, the torque output from the motor 2 is transmitted to the ring gear 51 via the reduction gear 4. The lower end of the ring gear 51 is located below the reduction gear 4. In the present embodiment, the lower end portion of the ring gear 51 is the portion located at the lowermost side in the differential device 5.

The case 6 is an outer case of the drive device 1. As shown in fig. 1, the housing 6 has a partition wall 61c that axially divides the inside of the motor housing portion 81 and the inside of the gear housing portion 82. The partition wall 61c is provided with a partition wall opening 68. The interior of the motor housing 81 and the interior of the gear housing 82 are connected to each other via the partition wall opening 68.

Oil O is contained in the casing 6. More specifically, the oil O is contained in the motor containing section 81 and the gear containing section 82. An oil reservoir P for storing oil O is provided in a lower region inside the gear housing 82. The oil level S of the oil reservoir P is located above the lower end of the ring gear 51. Thereby, the lower end portion of the ring gear 51 is immersed in the oil O in the gear housing portion 82. The oil level S of the oil reservoir P is located below the differential axis J3 and the axle 55.

The oil O in the oil reservoir P is delivered to the inside of the motor housing 81 through an oil passage 90 described later. The oil O sent to the inside of the motor housing 81 is accumulated in the lower region of the inside of the motor housing 81. At least a part of the oil O stored in the motor housing 81 moves to the gear housing 82 through the partition wall opening 68 and returns to the oil reservoir P.

In the present specification, the phrase "oil is contained in a certain portion" means that the oil is contained in the certain portion at least in a portion where the motor is being driven, and the oil may not be contained in the certain portion when the motor is stopped. For example, in the present embodiment, the oil O is stored in the motor storage portion 81, and it is sufficient that the oil is located inside the motor storage portion 81 in at least a part of the state where the motor 2 is being driven, and all of the oil O in the motor storage portion 81 may move to the gear storage portion 82 through the partition wall opening 68 when the motor 2 is stopped. A part of the oil O supplied to the inside of the motor housing 81 by the oil passage 90 described later may remain inside the motor housing 81 in a state where the motor 2 is stopped.

In the present specification, the phrase "the lower end portion of the ring gear is immersed in the oil in the gear housing" means that the lower end portion of the ring gear may be immersed in the oil in the gear housing at least in a part where the motor is driving, and the lower end portion of the ring gear may not be immersed in the oil in the gear housing in a part of a period where the motor is driving or the motor is stopped. For example, as a result of the oil O in the oil reservoir P being sent to the interior of the motor housing 81 by the oil passage 90 described later, the oil level S of the oil reservoir P may be lowered, and the lower end portion of the ring gear 51 may be temporarily left without being immersed in the oil O.

The oil O circulates in an oil passage 90 described later. The oil O is used for lubrication of the reduction gear 4 and the differential 5. In addition, the oil O is used for cooling the motor 2. As the oil O, in order to realize the functions of a lubricating oil and a cooling oil, it is preferable to use an oil having a relatively low viscosity equivalent to an Automatic Transmission lubricating oil (ATF).

As shown in fig. 1, the bottom 82a of the gear housing 82 is located below the bottom 81a of the motor housing 81. Therefore, the oil O fed from the inside of the gear housing portion 82 into the motor housing portion 81 easily flows into the gear housing portion 82 through the partition wall opening 68. As shown in fig. 2, the gear housing 82 extends in the front-rear direction. The end of the gear housing 82 on the front side (+ X side) is connected to the end of the motor housing 81 on the left side (+ Y side). The rear side (-X side) end of the gear housing 82 protrudes rearward beyond the motor housing 81.

The gear housing 82 has a projection 82 b. The protruding portion 82b is a portion protruding rearward (X side) and downward from the end portion on the left side (+ Y side) of the motor housing portion 81. The projection 82b has a circular hole 82c centered on the differential axis J3. The hole 82c axially penetrates the projection 82 b. Although not shown, the axle 55 passes through the hole 82 c.

The gear housing 82 has a pump mounting portion 88 to which an electric oil pump 96 is mounted. In the present embodiment, the pump mounting portion 88 protrudes rightward from the right side (-Y side) surface of the protruding portion 82 b. The pump mounting portion 88 has a substantially rectangular parallelepiped shape. The pump mounting portion 88 is positioned on the front side (+ X side) and lower side of the hole portion 82 c. The pump mounting portion 88 is located below the motor housing portion 81. Although not shown, the pump mounting portion 88 has a hole portion into which the electric oil pump 96 is inserted. The hole portion is recessed to the left side (+ Y side) from the right side surface of the pump mounting portion 88.

The motor housing 81 has a cylindrical shape surrounding the motor axis J1. The motor housing 81 is, for example, substantially cylindrical and extends in the axial direction. As shown in fig. 3, the motor housing portion 81 has a cooler attachment portion 83 to which the oil cooler 70 is attached. In the present embodiment, the cooler attachment portion 83 is provided in a lower portion of the front side (+ X side) portion of the motor housing portion 81. The cooler attachment portion 83 is located on the front side and lower side of the motor axis J1. The cooler attachment portion 83 protrudes obliquely downward toward the front. The cooler attachment portion 83 has a substantially rectangular parallelepiped shape.

As shown in fig. 4, the front end surface of the protruding cooler attachment portion 83 is an attachment surface 83a to which the oil cooler 70 is attached. The mounting surface 83a is a flat surface inclined downward toward the front side. The mounting surface 83a has, for example, a substantially rectangular shape with a pair of edges in the axial direction. Female screw holes 85 are provided at four corners of the attachment surface 83 a. The mounting surface 83a forms a part of the radially outer surface of the motor housing 81.

The mounting surface 83a has an oil flow outlet 92ba, an oil flow inlet 92ca, a refrigerant flow outlet 97ba, and a refrigerant flow inlet 97ca that are open. The oil flow outlet 92ba, the oil flow inlet 92ca, the refrigerant flow outlet 97ba, and the refrigerant flow inlet 97ca are circular openings.

The oil outlet 92ba is an end portion on the downstream side of the 2 nd oil flow path 92b described later. The oil O flowing out of the oil flow outlet 92ba flows into the interior of the oil cooler 70. The oil flow inlet 92ca is an upstream end of a 3 rd oil flow passage 92c described later. The oil O flows from the inside of the oil cooler 70 into the oil flow inlet 92 ca.

The refrigerant outlet 97ba is a downstream end of a 1 st refrigerant flow path 97b described later. The refrigerant W flowing out of the refrigerant outlet 97ba flows into the oil cooler 70. The refrigerant inlet 97ca is an upstream end of a 2 nd refrigerant passage 97c described later. The refrigerant W flows into the refrigerant inlet 97ca from the inside of the oil cooler 70.

The oil flow outlet 92ba, the oil flow inlet 92ca, the refrigerant flow outlet 97ba, and the refrigerant flow inlet 97ca are disposed so as to surround the center portion of the mounting surface 83 a. The oil flow outlet 92ba, the oil flow inlet 92ca, the refrigerant flow outlet 97ba, and the refrigerant flow inlet 97ca are, for example, rectangular in shape with their vertexes. The oil flow outlet 92ba and the oil flow inlet 92ca are diagonally arranged with the center portion of the mounting surface 83a interposed therebetween. The refrigerant outlet 97ba and the refrigerant inlet 97ca are diagonally arranged with the center of the mounting surface 83a interposed therebetween.

The oil outflow port 92ba and the refrigerant outflow port 97ba are arranged at intervals in the axial direction. The oil flow outlet 92ba is located on the left side (+ Y side) of the refrigerant flow outlet 97 ba. The oil flow inlet 92ca and the refrigerant flow inlet 97ca are arranged at an interval in the axial direction. The oil flow inlet 92ca is located on the right side (-Y side) of the refrigerant flow inlet 97 ca.

The cooler attachment portion 83 has a recess 84 recessed obliquely upward from the center portion of the attachment surface 83a toward the rear side (-X side). The recess 84 has a cross shape having 4

arm portions

84a, 84b, 84c, and 84d when viewed in a direction perpendicular to the mounting surface 83 a. The arm portion 84a is located between the refrigerant outflow port 97ba and the oil flow inlet port 92 ca. The arm portion 84b is located between the oil flow inlet 92ca and the refrigerant flow inlet 97 ca. The arm portion 84c is positioned between the refrigerant inflow port 97ca and the oil outflow port 92 ba. The arm portion 84d is located between the oil flow outlet 92ba and the refrigerant flow outlet 97 ba. By providing such a recess 84, the thickness of the cooler attachment portion 83 can be easily made nearly uniform. Therefore, when the case 6 is manufactured by die casting, the occurrence of cast holes in the cooler attachment portion 83 can be suppressed.

A cylindrical portion 86 protruding obliquely upward toward the front side (+ X side) is provided on the upper surface of the cooler attachment portion 83. The cylindrical portion 86 opens obliquely upward toward the front side. The opening of the cylinder 86 is a refrigerant outflow port 97 cb. The refrigerant outlet 97cb is an end portion on the downstream side of a 2 nd refrigerant passage 97c described later. A piping connector 87 is attached to the refrigerant outflow port 97 cb. Although not shown, a pipe for connecting the 2 nd refrigerant passage 97c to a radiator, not shown, is connected to the pipe connector 87.

As shown in fig. 2 and 3, the inverter unit 8 is fixed to the rear side of the motor housing 81. The inverter unit 8 is located above the pump mounting portion 88 and the cooler mounting portion 83. The inverter unit 8 is located above the electric oil pump 96 and the oil cooler 70. The inverter unit 8 is located on the upper side of the differential axis J3. Although not shown, the inverter unit 8 is located above the axle 55 through the hole 82 c.

As shown in fig. 1, the drive device 1 is provided with an oil passage 90 through which oil O circulates inside the casing 6. The oil passage 90 is a path of the oil O that supplies the oil O from the oil reservoir P to the motor 2 and guides the oil O to the oil reservoir P again. The oil passage 90 is provided across the inside of the motor housing 81 and the inside of the gear housing 82.

In the present specification, the term "oil passage" means an oil path. Therefore, the "oil passage" includes not only a "flow passage" for constantly flowing oil in one direction but also a concept of a path for temporarily accumulating oil and a path for dropping oil. The path for temporarily retaining oil includes, for example, a reservoir for storing oil.

The oil passage 90 has a 1 st oil passage 91 and a 2 nd oil passage 92. The 1 st oil passage 91 and the 2 nd oil passage 92 circulate oil O inside the casing 6, respectively. The 1 st oil passage 91 has an upward feed passage 91a, a shaft supply passage 91b, an in-shaft passage 91c, and an in-rotor passage 91 d. Further, a 1 st reservoir 93 is provided in a path of the 1 st oil path 91. The 1 st reservoir 93 is provided in the gear housing 82.

The upward feed path 91a is a path for feeding the oil O from the oil reservoir P by the rotation of the ring gear 51 of the differential device 5 and receiving the oil O from the 1 st reservoir 93. The 1 st reservoir 93 opens to the upper side. The 1 st reservoir 93 receives oil O sent up by the ring gear 51. Further, the 1 st reservoir 93 receives the oil O sent upward by the 2 nd gear 42 and the 3 rd gear 43 in addition to the oil O sent upward by the ring gear 51, for example, in a case where the liquid level of the oil reservoir P is high immediately after the motor 2 is driven.

The shaft supply path 91b guides the oil O from the 1 st reservoir 93 to the hollow portion 22 of the shaft 21. The shaft inner path 91c is a path through which the oil O passes through the hollow portion 22 of the shaft 21. The inner rotor path 91d is a path through which the oil O passes from the communication hole 23 of the shaft 21 to the inside of the rotor main body 24 and scatters toward the stator 30.

In the in-shaft path 91c, a centrifugal force is applied to the oil O inside the rotor 20 in accordance with the rotation of the rotor 20. Thereby, the oil O continuously scatters outward in the radial direction from the rotor 20. The path inside the rotor 20 becomes negative pressure as the oil O is scattered, and the oil O stored in the 1 st reservoir 93 is sucked into the rotor 20 to fill the path inside the rotor 20 with the oil O.

The oil O having reached the stator 30 absorbs heat from the stator 30. The oil O that has cooled the stator 30 drops downward and is accumulated in the lower region in the motor housing 81. The oil O accumulated in the lower region of the motor housing 81 moves to the gear housing 82 through the partition wall opening 68 provided in the partition wall 61 c. As described above, the 1 st oil path 91 supplies the oil O to the rotor 20 and the stator 30.

In the 2 nd oil passage 92, the oil O is lifted from the oil reservoir P to the upper side of the stator 30 and supplied to the stator 30. That is, the 2 nd oil passage 92 supplies the oil O to the stator 30 from the upper side of the stator 30. In the 2 nd oil passage 92, an electric oil pump 96, an oil cooler 70, and the 2 nd accumulator 10 are provided. The 2 nd oil passage 92 has a 1 st oil passage 92a, a 2 nd oil passage 92b, and a 3 rd oil passage 92 c.

The 1 st oil flow path 92a, the 2 nd oil flow path 92b, and the 3 rd oil flow path 92c are provided in a wall portion of the casing 6. The 1 st oil flow path 92a connects the oil reservoir P and the electric oil pump 96. The 2 nd oil flow path 92b connects the electric oil pump 96 and the oil cooler 70. As shown in fig. 4, the 2 nd oil flow passage 92b has an oil flow outlet 92ba that opens to the mounting surface 83a of the cooler mounting portion 83.

As shown in fig. 1, the 3 rd oil flow path 92c extends upward from the oil cooler 70. The 3 rd oil flow path 92c is provided in a wall portion of the motor housing portion 81. As shown in fig. 4, the 3 rd oil flow passage 92c has an oil flow inlet 92ca that opens to the mounting surface 83a of the cooler mounting portion 83. Although not shown, the 3 rd oil flow path 92c has a supply port that opens into the motor housing 81 above the stator 30. The supply port supplies oil O to the inside of the motor housing 81.

The electric oil pump 96 feeds the oil O stored in the casing 6 to the motor 2. In the present embodiment, the electric oil pump 96 sucks the oil O from the oil reservoir P through the 1 st oil flow path 92a, and supplies the oil O to the motor 2 through the 2 nd oil flow path 92b, the oil cooler 70, the 3 rd oil flow path 92c, and the 2 nd reservoir 10.

Reservoir 2 10 forms a portion of 2 nd oil path 92. As shown in fig. 1, the 2 nd reservoir 10 is located inside the motor housing 81. The 2 nd reservoir 10 is located at an upper side of the stator 30. The 2 nd reservoir 10 is supported from the lower side by the stator 30 and is provided to the motor 2. The 2 nd reservoir 10 is made of, for example, a resin material.

In the present embodiment, the 2 nd reservoir 10 has a gutter shape opening to the upper side. Reservoir 2 stores oil O. In the present embodiment, the 2 nd reservoir 10 stores the oil O supplied into the motor housing portion 81 through the 3 rd oil flow path 92 c. The 2 nd reservoir 10 has a supply port that supplies oil O to the coil ends 33a, 33 b. Thereby, the oil O stored in the 2 nd reservoir 10 can be supplied to the stator 30.

The oil O supplied from the 2 nd reservoir 10 to the stator 30 drops downward and is accumulated in the lower region in the motor housing 81. The oil O accumulated in the lower region of the motor housing 81 moves to the gear housing 82 through the partition wall opening 68 provided in the partition wall 61 c. As described above, the 2 nd oil passage 92 supplies the oil O to the stator 30.

As shown in fig. 2, the electric oil pump 96 is mounted to the pump mounting portion 88. More specifically, a part of the electric oil pump 96 is housed in a hole provided in the pump mounting portion 88 and is mounted to the pump mounting portion 88. A portion of the electric oil pump 96 on the left side (+ Y side) is housed in a hole portion of the pump mounting portion 88. The electric oil pump 96 is located below the motor housing 81.

The electric oil pump 96 has: a motor unit not shown; a pump section, not shown, which is rotated by a motor section; a housing 96a that houses the motor section and the pump section; and a connector portion 96 d. Although not shown, in the present embodiment, the rotary shaft of the motor portion of the electric oil pump 96 extends in the axial direction.

The case 96a has a heat sink 96e located outside the housing 6. That is, the electric oil pump 96 has a radiator 96 e. The heat sink 96e is a cover provided at the right side (-Y side) end portion in the housing 96 a. The radiator 96e radiates heat of an inverter, not shown, and the like housed in the casing 96a to the outside. The heat sink 96e has a housing portion 96b and a plurality of fins 96 c.

A capacitor, not shown, for example, is accommodated in the accommodating portion 96 b. The plurality of fins 96c extend in the front-rear direction. The plurality of fins 96c are plate-shaped with the plate surface facing in the vertical direction. In the present embodiment, the plurality of fins 96c includes a plurality of fins 96c extending from the housing portion 96b to the front side (+ X side) and a plurality of fins 96c extending from the housing portion 96b to the rear side (-X side). The plurality of fins 96c extending forward from the housing portion 96b are disposed at intervals in the vertical direction. The plurality of fins 96c extending rearward from the housing portion 96b are disposed at intervals in the vertical direction.

As shown in fig. 5, at least a part of the heat sink 96e is exposed at the front side (+ X side). In the present embodiment, a part of the housing portion 96b and the plurality of fins 96c extending forward from the housing portion 96b among the plurality of fins 96c are exposed forward.

In the present specification, the phrase "a certain object is exposed to one side" means that the certain object can be visually confirmed when the driving device is viewed from one side. That is, the phrase "at least a part of the heat sink 96e is exposed to the front side" means that at least a part of the heat sink 96e can be visually confirmed when the drive device 1 is viewed from the front side.

As shown in fig. 2, the connector portion 96d protrudes to the right side (-Y side) from the side surface on the front side of the housing 96 a. The connector portion 96d is located outside the housing 6. The connector portion 96d is located below the motor housing portion 81. The connector portion 96d is located on the front side (+ X side) of the heat sink 96 e. The right end of connector portion 96d is located on the right side of heat sink 96 e. The connector portion 96d is open to the right side. The connector portion 96d is electrically connected to a power supply not shown. The electric oil pump 96 is driven by supplying electric power from a power supply, not shown, through the connector portion 96 d.

The oil cooler 70 cools the oil O contained inside the housing 6. The oil cooler 70 is located outside the housing 6. As shown in fig. 3, the oil cooler 70 has a shape that is long in the axial direction. In the present embodiment, the oil cooler 70 has a substantially rectangular parallelepiped shape that is long in the axial direction.

In the present specification, the phrase "the oil cooler is formed in a shape elongated in the axial direction" includes a case where the dimension of the oil cooler in the axial direction is larger than the dimension of the oil cooler in the direction perpendicular to the axial direction. In the present embodiment, the dimension of the oil cooler 70 in the axial direction is larger than the dimension of the oil cooler 70 in the front-rear direction and the vertical direction.

The oil cooler 70 is mounted to the housing 6. In the present embodiment, the oil cooler 70 is attached to the motor housing 81. More specifically, the oil cooler 70 is attached to the cooler attachment portion 83 of the motor housing portion 81. As described above, the cooler mount portion 83 is provided in the lower portion of the front side (+ X side) portion of the motor housing portion 81. That is, in the present embodiment, the oil cooler 70 is attached to a portion of the motor housing 81 located on the front side. In the present embodiment, the oil cooler 70 is attached to a lower portion of the motor housing 81.

In the present specification, the "portion of the motor housing portion located on the front side" includes a portion of the motor housing portion located on the front side of the motor shaft. In the present specification, the "portion of the motor housing portion located on the lower side" includes a portion of the motor housing portion located on the lower side of the motor shaft.

The oil cooler 70 is attached to the attachment surface 83a of the cooler attachment portion 83. As described above, the mounting surface 83a constitutes a part of the radially outer surface of the motor housing 81. That is, in the present embodiment, the oil cooler 70 is attached to the radially outer surface of the motor housing 81.

As shown in fig. 6 and 7, an internal oil flow passage 74 through which the oil O flows and an internal refrigerant flow passage 73 through which the refrigerant W flows are provided inside the oil cooler 70. The internal oil passage 74 is a part of the 2 nd oil passage 92, and is a passage connecting the 2 nd oil passage 92b and the 3 rd oil passage 92 c.

The internal refrigerant passage 73 is a part of a refrigerant circulation passage 97 through which the refrigerant W cooled by a radiator, not shown, circulates. As shown in fig. 1, the refrigerant circulation passage 97 is a circulation passage through which the refrigerant W from the radiator passes through the inverter unit 8 and the oil cooler 70 in this order and returns to the radiator again. The refrigerant W is, for example, water. The inverter unit 8 is cooled by the refrigerant W passing through the refrigerant circulation passage 97. The oil O passing through the internal oil flow passage 74 of the oil cooler 70 is cooled by the refrigerant W passing through the refrigerant circulation passage 97. In this way, oil cooler 70 cools oil O passing through 2 nd oil passage 92 by heat exchange with refrigerant W.

As shown in fig. 4, the refrigerant circulation passage 97 includes a pipe 97a provided in the drive device 1, and a 1 st refrigerant passage 97b and a 2 nd refrigerant passage 97c provided in the casing 6. The pipe 97a is located outside the casing 6. As shown in fig. 3, in the present embodiment, the pipe 97a extends from the inverter unit 8 to the cooler attachment portion 83. The refrigerant W after passing through the inside of the inverter unit 8 flows through the pipe 97 a. The pipe 97a passes through the right side (-Y side) of the motor housing portion 81. On the right side of the motor housing portion 81, the pipe 97a extends obliquely in a direction toward the lower side as it goes toward the front side (+ X side).

As shown in fig. 5, the pipe 97a overlaps at least a part of the connector portion 96d of the electric oil pump 96 when viewed in the front-rear direction. In the present embodiment, the portion of the pipe 97a connected to the cooler attachment portion 83 overlaps with a portion of the connector portion 96d when viewed in the front-rear direction. The portion of the pipe 97a connected to the cooler mounting portion 83 is located on the front side (+ X side) of the right side (-Y side) portion of the connector portion 96 d.

As shown in fig. 4, the 1 st refrigerant passage 97b and the 2 nd refrigerant passage 97c are provided inside the cooler attachment 83. The 1 st refrigerant passage 97b is a passage connecting the pipe 97a and the internal refrigerant passage 73. Although not shown, the 1 st refrigerant passage 97b has a refrigerant inlet connected to the pipe 97 a. The 1 st refrigerant flow path 97b has a refrigerant outlet 97ba provided on the mounting surface 83a of the cooler mounting portion 83. The 2 nd refrigerant passage 97c is a passage connected to the internal refrigerant passage 73. The 2 nd refrigerant flow path 97c includes: a refrigerant inlet 97ca provided on the mounting surface 83a of the cooler mounting portion 83; and a refrigerant outflow port 97cb provided on an end surface of the tube portion 86. The 1 st refrigerant flow path 97b and the 2 nd refrigerant flow path 97c are connected to each other through the internal refrigerant flow path 73.

As shown in fig. 6, the oil cooler 70 has an oil cooler body 71 and a base 72. The oil cooler body 71 has a substantially rectangular parallelepiped shape that is long in the axial direction. The oil cooler main body 71 projects obliquely downward from the base 72 toward the front side (+ X side). The base 72 is a portion fixed to the mounting surface 83 a. The base 72 has a base main body 72a and 4 fixing portions 72b protruding from an outer edge portion of the base main body 72 a. Through holes 72c are provided in the 4 fixing portions 72b, respectively. The oil cooler 70 is fixed to the cooler attachment portion 83 by screwing screws inserted through the through holes 72c into female screw holes 85 provided in the attachment surface 83 a.

The base portion 72 has a mounting surface 72d that contacts the mounting surface 83a, and the refrigerant inlet 73a and the refrigerant outlet 73b of the internal refrigerant passage 73 and the oil inlet 74a and the oil outlet 74b of the internal oil passage 74 are open. The refrigerant inlet 73a, the refrigerant outlet 73b, the oil inlet 74a, and the oil outlet 74b are circular openings.

The refrigerant inlet 73a, the refrigerant outlet 73b, the oil inlet 74a, and the oil outlet 74b are, for example, rectangular in shape with respective vertexes. The refrigerant inlet 73a and the refrigerant outlet 73b are diagonally arranged. The oil flow inlet 74a and the oil flow outlet 74b are diagonally arranged.

As shown in fig. 7, the refrigerant outlet 73b is connected to a refrigerant inlet 97ca provided in the cooler attachment portion 83. Although not shown, the refrigerant inlet 73a is connected to a refrigerant outlet 97ba provided in the cooler attachment portion 83. Thereby, the 1 st refrigerant passage 97b and the 2 nd refrigerant passage 97c are connected to each other through the internal refrigerant passage 73.

The oil flow inlet 74a is connected to an oil flow outlet 92ba provided in the cooler mount portion 83. Although not shown, the oil flow outlet 74b is connected to the oil flow inlet 92 ca. Thereby, the 2 nd oil flow passage 92b and the 3 rd oil flow passage 92c are connected via the internal oil flow passage 74.

As shown in fig. 6, a sealing recess 73c is provided in the peripheral edge portion of the refrigerant inlet 73a of the mounted surface 72 d. The refrigerant inlet 73a is provided in the bottom surface of the sealing recess 73 c. The inner edge of the sealing recess 73c has a circular shape concentrically arranged with the refrigerant inlet 73 a. A sealing recess 73d is provided in the peripheral edge of the refrigerant outlet 73b of the mounted surface 72 d. The refrigerant outflow port 73b is provided in the bottom surface of the seal recess 73 d. The inner edge of the sealing recess 73d has a circular shape concentrically arranged with the refrigerant outflow port 73 b.

A sealing recess 74c is provided in a peripheral edge portion of the oil flow inlet 74a in the mounted surface 72 d. The oil flow inlet 74a is provided at the bottom surface of the seal recess 74 c. The inner edge of the seal recess 74c has a circular shape concentrically arranged with the oil flow inlet 74 a. A sealing recess 74d is provided in a peripheral edge portion of the oil flow outlet 74b in the mounted surface 72 d. The oil flow outlet 74b is provided at the bottom surface of the seal recess 74 d. The inner edge of the seal recess 74d has a circular shape concentrically arranged with the oil flow outlet 74 b. The inner diameters of the seal recesses 73c and 73d are larger than the inner diameters of the seal recesses 74c and 74d, for example.

As shown in fig. 7, an annular O-ring 75a is fitted into the seal recess 73 d. When viewed in the direction perpendicular to the mounting surface 72d, the O-ring 75a surrounds the refrigerant inlet 97ca and the refrigerant outlet 73 b. The O-ring 75a is pressed against the bottom surface of the seal recess 73d by the mounting surface 83a and is in a compressed and elastically deformed state. Thus, the O-ring 75a seals the mounting surface 83a and the mounting surface 72d within one circle surrounding the refrigerant inlet 97ca and the refrigerant outlet 73 b. Therefore, the refrigerant W flowing between the internal refrigerant flow path 73 and the 2 nd refrigerant flow path 97c can be suppressed from leaking from the gap between the mounting surface 83a and the mounting surface 72 d.

No wall portion is provided on the inner side of the O-ring 75 a. Therefore, the inner diameter of the O-ring 75a is not limited by the inner wall portion, and the degree of freedom in selecting the inner diameter of the O-ring 75a with respect to the inner diameter of the refrigerant inlet 97ca and the inner diameter of the refrigerant outlet 73b can be increased. The outer edge of the O-ring 75a in a compressed and elastically deformed state contacts the inner circumferential surface of the seal recess 73 d. When viewed in a direction perpendicular to the mounting surface 72d, the inner edge of the compression-elastically deformed O-ring 75a is positioned outward of the inner edge of the refrigerant inlet 97ca and the inner edge of the refrigerant outlet 73 b. The compression rate of the O-ring 75a that is elastically deformed by compression is higher than in the case where a wall portion is provided on the inner side of the O-ring 75 a. Although not shown, an annular O-ring 75a is fitted into the seal recess 73c, similarly to the seal recess 73 d.

An annular O-ring 75b is fitted into the seal recess 74 c. The O-ring 75b surrounds the oil flow outlet port 92ba and the oil flow inlet port 74a when viewed in the direction perpendicular to the mounted surface 72 d. The O-ring 75b is pressed against the bottom surface of the seal recess 74c by the mounting surface 83a and is in a compressed and elastically deformed state. Thus, the O-ring 75b seals between the mounting surface 83a and the mounted surface 72d within a single circle surrounding the oil flow outlet 92ba and the oil flow inlet 74 a. Therefore, the refrigerant W flowing between the internal oil flow passage 74 and the 2 nd oil flow passage 92b can be suppressed from leaking from the gap between the mounting surface 83a and the mounting surface 72 d.

No wall portion is provided on the inner side of the O-ring 75 b. Therefore, the inner diameter of the O-ring 75b is not limited by the inner wall portion, and the degree of freedom in selecting the inner diameter of the O-ring 75b with respect to the inner diameter of the oil flow outlet 92ba and the inner diameter of the oil flow inlet 74a can be increased. The outer edge of the O-ring 75b in a compressed and elastically deformed state contacts the inner circumferential surface of the seal recess 74 c. The inner edge of the O-ring 75b in the compression elastically deformed state is positioned further outside than the inner edge of the oil flow outlet port 92ba and the inner edge of the oil flow inlet port 74a as viewed in the direction perpendicular to the mounted surface 72 d. The compression rate of the O-ring 75b that is elastically deformed by compression is higher than in the case where a wall portion is provided on the inner side of the O-ring 75 b. Although not shown, an annular O-ring 75b is fitted into the seal recess 74d, similarly to the seal recess 74 c. The inner diameter of the O-ring 75b is smaller than the inner diameter of the O-ring 75 a. O-ring 75b has a smaller outer diameter than O-ring 75 a.

As shown in fig. 5, the oil cooler 70 overlaps at least a part of the connector portion 96d of the electric oil pump 96 when viewed in the front-rear direction. Therefore, at least a part of the connector portion 96d can be covered in the front-rear direction by the oil cooler 70. This allows the connector portion 96d to be protected by the oil cooler 70. Therefore, a member for protecting the connector portion 96d is not separately provided, and damage to the connector portion 96d can be suppressed when the driving device 1 receives an impact, when a flying stone exists, or the like. Therefore, an increase in the number of components of the drive device 1 can be suppressed, and a failure in the driving of the electric oil pump 96 can be suppressed.

Further, according to the present embodiment, the pipe 97a overlaps at least a part of the connector portion 96d when viewed in the front-rear direction. Therefore, the connector portion 96d can be protected in the front-rear direction by the oil cooler 70 and the pipe 97 a. Therefore, damage to connector portion 96d can be further suppressed.

In the present embodiment, a part of the oil cooler 70 is located on the front side (+ X side) of the connector portion 96 d. Therefore, when the drive device 1 receives an impact from the front side, the oil cooler 70 can easily receive the impact, and damage to the connector portion 96d can be suppressed. In the present embodiment, the right side (-Y side) end of the oil cooler 70 covers the left side (+ Y side) portion of the connector portion 96d from the front side. Here, in the present embodiment, a part of the pipe 97a is positioned on the front side of the right side portion of the connector portion 96 d. Therefore, in the present embodiment, substantially the entire connector portion 96d can be covered from the front side by the oil cooler 70 and the pipe 97 a. Therefore, damage to connector portion 96d can be further suppressed.

In the present embodiment, the entire oil cooler 70 is located at a position shifted from at least a part of the radiator 96e of the electric oil pump 96 as viewed in the front-rear direction. Therefore, at least a part of the radiator 96e is not covered by the oil cooler 70 in the front-rear direction. Thus, the flow of air in the front-rear direction generated around the drive device 1 during vehicle traveling is not blocked by the oil cooler 70, and is easily blown to a part of the radiator 96 e. Therefore, heat dissipation from the radiator 96e can be promoted, and the heat dissipation performance of the electric oil pump 96 can be improved. As described above, according to the present embodiment, the connector portion 96d is covered and protected in the front-rear direction by the oil cooler 70, and at least a part of the radiator 96e is not covered by the oil cooler 70, whereby both the suppression of damage to the connector portion 96d and the improvement of the heat radiation performance of the electric oil pump 96 can be achieved. Therefore, the occurrence of a failure in the electric oil pump 96 can be further suppressed.

In addition, according to the present embodiment, at least a part of the heat sink 96e is exposed at the front side (+ X side). Therefore, air flowing from the front side to the rear side (the (-X side)) is easily blown to the radiator 96e when the vehicle is traveling forward, so that heat dissipation from the radiator 96e can be further promoted. This can further improve the heat dissipation performance of the electric oil pump 96.

In addition, according to the present embodiment, the heat sink 96e has a plurality of fins 96c extending in the front-rear direction. Therefore, air flowing in the front-rear direction easily flows along the fins 96c when the vehicle is running. This enables the heat to be appropriately radiated from the heat radiation fins 96c to the air. Therefore, the heat radiation performance of the electric oil pump 96 can be further improved.

In the present embodiment, the right side (-Y side) end of the oil cooler 70 is positioned on the left side (+ Y side) of the right side end of the radiator 96 e. That is, the oil cooler 70 is arranged offset to the left with respect to the radiator 96 e. The right end of the oil cooler 70 protrudes rightward from the cooler attachment portion 83.

According to the present embodiment, the oil cooler 70 has a shape that is long in the axial direction of the differential axis J3. Therefore, the oil cooler 70 can be made long in the direction perpendicular to the front-rear direction in which the vehicle travels. This makes it possible to easily blow the air flow in the front-rear direction generated around the drive device 1 to the oil cooler 70 during the traveling of the vehicle. Therefore, the oil cooler 70 can be cooled from the outside by the flow of air generated by the vehicle running. Therefore, the oil O and the refrigerant W flowing through the oil cooler 70 can be appropriately cooled by the air. This can improve the cooling efficiency of the oil cooler 70 for the oil O.

Further, by forming the oil cooler 70 in a shape that is long in the axial direction of the differential axis J3, the volume of the oil cooler 70 is easily increased. Therefore, the amount of heat exchange in the oil cooler 70 is easily increased. This can further improve the cooling efficiency of the oil cooler 70 for the oil O. As described above, according to the present embodiment, the cooling efficiency of the drive device 1 can be improved. Further, by forming the oil cooler 70 in a shape that is long in the axial direction of the differential axis J3, as described above, the connector portion 96d is easily covered with the oil cooler 70. Therefore, the connector portion 96d is easily protected by the oil cooler 70, and damage to the connector portion 96d can be further suppressed.

In addition, according to the present embodiment, the oil cooler 70 is mounted on a portion of the motor housing 81 located on the front side (+ X side). Therefore, when the vehicle is moving forward, air flowing from the front side to the rear side (-X side) is easily blown to the oil cooler 70, and the oil cooler 70 is more easily cooled. This can further improve the cooling efficiency of the oil O by the oil cooler 70, and can further improve the cooling efficiency of the drive device 1.

In addition, according to the present embodiment, the oil cooler 70 is exposed on the front side (+ X side). Therefore, the air flowing from the front side to the rear side (X side) is more easily blown to the oil cooler 70 by the vehicle advancing. This enables the oil cooler 70 to be further cooled, and the cooling efficiency of the drive device 1 to be further improved.

In addition, according to the present embodiment, the oil cooler 70 is provided in a portion of the motor housing 81 located on the lower side. Therefore, the wind blown in from the lower side of the vehicle is easily blown to the oil cooler 70 during the vehicle running or the like. This makes it easier to cool the oil cooler 70. Therefore, the cooling efficiency of the oil cooler 70 for the oil O can be further improved, and the cooling efficiency of the drive device 1 can be further improved.

In addition, according to the present embodiment, the oil cooler 70 is exposed at the lower side. Therefore, the wind blown in from the lower side of the vehicle is more easily blown to the oil cooler 70. This enables the oil cooler 70 to be further cooled, and the cooling efficiency of the drive device 1 to be further improved.

In the present embodiment, the motor housing 81 has a cylindrical shape surrounding the motor axis J1. Therefore, for example, in the case where the oil cooler is long in the direction perpendicular to the motor axis J1, if the oil cooler is attached to the radially outer side surface of the motor housing 81, the oil cooler is likely to protrude largely from the motor housing 81. This may increase the size of the entire drive device.

In contrast, according to the present embodiment, the oil cooler 70 is long in the same axial direction as the direction in which the motor axis J1 extends, and is attached to the radially outer surface of the motor housing 81. Therefore, even if the oil cooler 70 is formed in a shape that is long in one direction, it is possible to suppress the oil cooler 70 from protruding greatly from the motor housing 81. This can improve the cooling efficiency of the drive device 1 and suppress an increase in size of the drive device 1. Further, since the oil cooler 70 is made longer in the axial direction, the volume of the oil cooler 70 can be increased, and therefore, the cooling efficiency of the oil O by the oil cooler 70 can be improved while suppressing the increase in size of the oil cooler 70 in the direction perpendicular to the axial direction.

The present invention is not limited to the above embodiment, and other configurations may be adopted. The shape of the oil cooler is not particularly limited as long as it is long in the axial direction of the differential axis. The shape of the oil cooler may be, for example, a cylindrical shape or a polygonal columnar shape. The position where the oil cooler is provided is not particularly limited as long as it is outside the housing. The oil cooler may be attached to a portion of the motor housing portion located on the upper side, or may be attached to a portion of the motor housing portion located on the rear side. The oil cooler may be attached to the gear housing. The oil cooler may be mounted on an axial side surface of the housing.

The structure of the oil cooler is not particularly limited as long as the oil can be cooled. The oil cooler may or may not overlap with the entire connector portion of the electric oil pump when viewed in the front-rear direction. The oil cooler may not be exposed to the front side or the lower side. The oil cooler may be exposed at the upper side or the rear side. The oil cooler may cover the entire radiator of the electric oil pump.

In the electric oil pump, the direction in which the plurality of fins extend is not particularly limited, and may extend in a direction other than the front-rear direction. The shape of the plurality of fins is not particularly limited, and may be a rod or the like. The heat sink may not have fins. The heat sink may not be provided. The electric oil pump may not be provided. A duct for flowing air toward the oil cooler may be provided in the drive device. In this case, the oil cooler can be cooled more appropriately, and the cooling efficiency of the drive apparatus can be improved more appropriately.

The respective structures described in the present specification can be appropriately combined within a range not contradictory to each other.

Claims

1. A drive device for rotating an axle of a vehicle,

the driving device comprises:

a motor;

a reduction gear connected to the motor;

a differential device connected to the motor via the reduction gear, and configured to rotate the axle about a differential axis;

a case that contains oil therein and that has a motor containing portion that contains the motor therein and a gear containing portion that contains the reduction gear and the differential gear therein; and

an oil cooler located outside the housing and cooling oil contained inside the housing,

the oil cooler is long in the axial direction of the differential axis.

2. The drive device according to claim 1,

the oil cooler is attached to a portion of the motor housing portion that is located on one side in the front-rear direction perpendicular to both the axial direction of the differential axis and the vertical direction.

3. The drive device according to claim 2,

the oil cooler is exposed on one side in the front-rear direction.

4. The drive device according to claim 1,

the oil cooler is attached to a portion of the motor housing portion located on a lower side in a vertical direction.

5. The drive device according to claim 2,

6. The drive device according to claim 3,

7. The drive device according to claim 4,

the oil cooler is exposed at the lower side in the vertical direction.

8. The drive device according to claim 5,

the oil cooler is exposed at the lower side in the vertical direction.

9. The drive device according to claim 6,

the oil cooler is exposed at the lower side in the vertical direction.

10. The drive device according to any one of claims 1 to 9,

the motor has a rotor rotatable about a motor axis extending in a direction parallel to the differential axis,

the motor housing portion has a cylindrical shape surrounding the motor axis,

the oil cooler is attached to a radially outer side surface of the motor housing.