阅读说明：本技术 车用电动驱动装置 (Electric drive device for vehicle ) 是由 吉见拓也 齐藤大辅 于 2020-05-13 设计创作，主要内容包括：本发明涉及车用电动驱动装置。在车用电动驱动装置中,在分别将传递轴中的被驱动外壳的两个支承部支承的两个部分之间的距离以及输入轴中的被传动外壳的两个支承部支承的两个部分之间的距离设为第一距离,将输入轴以及传递轴中的第一距离长的一方设为一个轴,将输入轴以及传递轴中的第一距离短的一方设为另一个轴,将驱动外壳以及传动外壳中的支承一个轴的一方设为一个外壳,将驱动外壳以及传动外壳中的支承另一个轴的一方设为另一个外壳的情况下,一个轴朝向另一个轴横穿第一中心轴而延伸,结合部收纳于另一个外壳。(The present invention relates to an electric drive device for a vehicle. In the electric drive device for a vehicle, when a distance between two portions of the transmission shaft supported by the two support portions of the driven housing and a distance between two portions of the input shaft supported by the two support portions of the driven housing are set to be a first distance, a longer first distance of the input shaft and the transmission shaft is set to be one shaft, a shorter first distance of the input shaft and the transmission shaft is set to be the other shaft, a first shaft of the driving housing and the transmission housing supporting the one shaft is set to be one housing, and a second shaft of the driving housing and the transmission housing supporting the other shaft is set to be the other housing, the one shaft extends toward the other shaft across the first center axis, and the coupling portion is housed in the other housing.)

1. An electric drive device for a vehicle, comprising:

an axle housing;

a drive shaft that is housed in the axle housing and is rotatable about a first center axis;

a motor that is located on a first direction side intersecting an axial direction of the first center shaft with respect to the axle housing and that has a motor shaft that rotates about a second center shaft along the first direction;

a first gear mechanism having: an input shaft at least a part of which is located on a side opposite to the first direction with respect to the axle housing and is rotatable about a third central axis along the first direction and to which power is input from the motor shaft, an output shaft rotatable about a fourth central axis parallel to the third central axis and arranged at an interval from the third central axis, and a plurality of gears interposed between the input shaft and the output shaft and transmitting the power;

a differential gear housed in the axle housing, coupled to the drive shaft and the output shaft, and transmitting the power from the output shaft to the drive shaft;

a through drive shaft that is rotatable about a third center axis along the first direction, the through drive shaft including a transmission shaft at least a portion of which is located on the first direction side with respect to the axle housing and to which power is input from the motor shaft, the input shaft, and a coupling portion that couples the transmission shaft and the input shaft;

a drive unit including the motor, the transmission shaft, and a drive housing that houses the motor and the transmission shaft and includes two support portions that support the transmission shaft so as to be rotatable about the third center axis, the drive unit being detachably attached to the axle housing and extending in the first direction from the axle housing; and

a transmission unit that includes the first gear mechanism and a transmission housing that houses the first gear mechanism and includes two support portions that support the input shaft so as to be rotatable about the third center axis, the transmission unit being detachably attached to the axle housing and extending from the axle housing in a direction opposite to the first direction,

in a case where a distance between two portions of the transmission shaft supported by the two support portions of the drive housing and a distance between two portions of the input shaft supported by the two support portions of the transmission housing are respectively set to first distances, one of the input shaft and the transmission shaft, which is longer than the first distance, is set to one shaft, one of the input shaft and the transmission shaft, which is shorter than the first distance, is set to the other shaft, one of the drive housing and the transmission housing, which supports the one shaft, is set to one housing, and one of the drive housing and the transmission housing, which supports the other shaft, is set to the other housing, the one shaft extends toward the other shaft across the first central axis, and the coupling portion is housed in the other housing.

2. The vehicular electric drive apparatus according to claim 1, wherein,

the drive unit includes: a second gear mechanism having a single gear stage including a first gear rotating integrally with the motor shaft, the transmission shaft, and a second gear transmitting the power from the first gear and rotating integrally with the transmission shaft,

the above-described first gear mechanism has a plurality of gear positions,

said one shaft is said input shaft and said one housing is said transmission housing.

3. The vehicular electric drive apparatus according to claim 2, wherein,

the plurality of gear stages of the first gear mechanism include: a plurality of drive gears provided on the input shaft, and a plurality of driven gears provided on the output shaft and transmitting the power from the plurality of drive gears,

the plurality of drive gears are provided between the two support portions of the transmission housing of the input shaft,

the second gear is provided between the two support portions of the drive housing of the transmission shaft.

4. The electric drive device for vehicle according to any one of claims 1 to 3,

the joint is supported by the other housing.

5. The electric drive device for vehicle according to any one of claims 1 to 4,

the coupling part has a female spline part provided on the one shaft and a male spline part provided on the other shaft and spline-coupled to the female spline part,

a coupling portion bearing is provided between the outer periphery of the female spline portion and the other housing.

6. The vehicular electric drive apparatus according to claim 5, wherein,

the two support portions of the drive housing support the transmission shaft rotatably about the third central axis via transmission shaft bearings,

the two support portions of the transmission housing support the input shaft rotatably about the third central axis via input shaft bearings,

the joint is supported by the other housing via a joint bearing,

the outer diameter of the coupling portion bearing is smaller than the outer diameters of the transmission shaft bearing and the input shaft bearing.

Technical Field

The present invention relates to an electric drive device for a vehicle.

Background

Conventionally, there is known an electric drive device for a vehicle, which includes a motor, a gear mechanism for performing speed change or the like, a differential gear, and a drive shaft, wherein the motor is disposed on one side of the differential gear, the gear mechanism is disposed on the other side, and power of the motor is transmitted to the gear mechanism via a through drive shaft.

Patent document 1: EP3501867A1

In such an electric drive device for a vehicle, it is assumed that a power transmission unit having a gear mechanism and a power transmission housing for housing the gear mechanism and a drive unit having a motor and a drive housing for housing the motor are configured, and the power transmission unit and the drive unit are attached to an axle housing for housing a differential gear and a drive shaft from both sides, respectively, to configure the electric drive device for a vehicle. In this case, it is assumed that, in order to perform test evaluation separately before the transmission unit and the drive unit are mounted on the axle housing, or to divide the through drive shaft depending on the mounting conditions or the like, for example, the coupling portion of the divided through drive shaft has a relatively large swing due to the rotation of the through drive shaft depending on the position and structure of the coupling portion, and thus there is a possibility that the vibration generated in the electric drive device for a vehicle becomes relatively large.

Therefore, one of the objects of the present invention is to obtain an electric drive device for a vehicle, which suppresses, for example, a vibration generated in a coupling portion due to rotation of a through drive shaft, and which easily suppresses the generation of a vibration.

Disclosure of Invention

The electric drive device for a vehicle according to the present invention includes, for example: an axle housing; a drive shaft that is housed in the axle housing and is rotatable about a first center axis; a motor that is located on a first direction side intersecting an axial direction of the first center shaft with respect to the axle housing and that has a motor shaft that rotates about a second center shaft along the first direction; a first gear mechanism having: an input shaft at least a part of which is located on a side opposite to the first direction with respect to the axle housing and is rotatable about a third central axis along the first direction and to which power is input from the motor shaft, an output shaft rotatable about a fourth central axis parallel to the third central axis and arranged at an interval from the third central axis, and a plurality of gears interposed between the input shaft and the output shaft and transmitting the power; a differential gear housed in the axle housing, coupled to the drive shaft and the output shaft, and transmitting the power from the output shaft to the drive shaft; a through drive shaft that is rotatable about a third center axis along the first direction, the through drive shaft including a transmission shaft at least a portion of which is located on the first direction side with respect to the axle housing and to which power is input from the motor shaft, the input shaft, and a coupling portion that couples the transmission shaft and the input shaft; a drive unit including the motor, the transmission shaft, and a drive housing that houses the motor and the transmission shaft and includes two support portions that support the transmission shaft so as to be rotatable about the third center axis, the drive unit being detachably attached to the axle housing and extending in the first direction from the axle housing; and a transmission unit including the first gear mechanism, and a transmission housing that houses the first gear mechanism and includes two support portions that support the input shaft so as to be rotatable about the third center axis, the transmission housing being detachably attached to the axle housing and extending from the axle housing in a direction opposite to the first direction, a distance between two portions of the transmission shaft supported by the two support portions of the drive housing and a distance between two portions of the input shaft supported by the two support portions of the transmission housing being respectively set to first distances, a longer one of the input shaft and the transmission shaft being set to be one shaft, a shorter one of the input shaft and the transmission shaft being set to be the other shaft, and a side of the drive housing and the transmission housing that supports the one shaft being set to be one housing, in the case where one of the drive housing and the transmission housing that supports the other shaft is defined as the other housing, the one shaft extends toward the other shaft across the first center axis, and the coupling portion is housed in the other housing.

According to the electric drive device for a vehicle of the embodiment of the present invention, compared to a configuration in which the other shaft having the shorter first distance extends toward the one shaft having the longer first distance across the first center axis and the coupling portion is housed in the one housing, it is easy to suppress the swing of the end portion on the coupling portion side of the one shaft having the longer first distance. That is, the effect of suppressing the hunting generated in the coupling portion by the rotation of the penetration drive shaft is high. Therefore, the electric drive device for a vehicle can be obtained in which the generation of vibration is easily suppressed.

Drawings

Fig. 1 is an exemplary plan view of an electric drive device for a vehicle according to a first embodiment.

Fig. 2 is an exemplary diagram showing a schematic configuration of the electric drive device for a vehicle according to the first embodiment.

Fig. 3 is an exemplary diagram showing a schematic configuration of an electric drive device for a vehicle according to a second embodiment.

Detailed Description

Hereinafter, exemplary embodiments of the present invention are disclosed. In the present specification, ordinal numbers are used to distinguish members, portions, and the like, and do not indicate order or priority. The following embodiments include the same components. The same reference numerals are assigned to the same components, and redundant description is omitted.

< first embodiment >

Fig. 1 is an exemplary plan view of an electric drive device 1 for a vehicle of the present embodiment. The electric drive device 1 for a vehicle is provided in a vehicle, and rotationally drives wheels 18L and 18R of the vehicle. In the following description, three directions orthogonal to each other are defined for convenience. The X direction is the same as the front in the vehicle front-rear direction, the Y direction is along the vehicle width direction (vehicle width direction), and the Z direction is the same as the upper side in the vehicle vertical direction. The electric drive apparatus 1 for a vehicle is also referred to as an electric axle apparatus.

Fig. 2 is an exemplary diagram showing a schematic configuration of electric drive device 1 for a vehicle according to the embodiment. As shown in fig. 2, the electric drive device 1 for a vehicle includes an axle housing 10, a motor 11, a coupling mechanism 12, a transmission 13, a differential gear 14, drive shafts 15L and 15R, a parking brake 16, and a parking lock gear 17. In the electric drive device 1 for a vehicle, power output from the motor 11 is transmitted to the drive shafts 15L and 15R via the connecting mechanism 12, the transmission 13, and the differential gear 14. Thereby, the wheels 18L, 18R fixed to the drive shafts 15L, 15R rotate.

As shown in fig. 1 and 2, the electric drive device 1 for a vehicle includes a drive unit 100 and a transmission unit 200.

As shown in fig. 2, the drive unit 100 has a motor 11, a connection mechanism 12, and a drive housing 101.

The drive unit 100 is detachably mounted to the axle housing 10 in a state of being positioned on the front side, which is the X-direction side of the axle housing 10. The drive unit 100 extends from the axle housing 10 in the X direction, i.e., forward. In other words, the drive unit 100 protrudes from the axle housing 10 in the X direction. The X direction is an example of the first direction.

The transmission unit 200 has a transmission 13, a differential gear 14, a parking brake 16, a parking lock gear 17, and a transmission housing 201. The power transmission unit 200 is detachably mounted to the axle housing 10 in a state of being located on the rear side, which is the opposite side of the axle housing 10 in the X direction.

The transmission unit 200 extends from the axle housing 10 in the opposite direction to the X direction, i.e., rearward. In other words, the transmission unit 200 protrudes from the axle housing 10 in the direction opposite to the X direction.

The drive unit 100 and the transmission unit 200 are mounted to the axle housing 10 independently of each other. In other words, the drive unit 100 and the power transmission unit 200 are mounted to the axle housing 10 separately from each other. That is, the motor 11 and the transmission 13 are mounted to the axle housing 10 independently of each other.

The axle housing 10 is a housing of a rigid axle, and houses a differential gear 14 and drive shafts 15L, 15R.

The axle housing 10 is constructed by a combination of a plurality of components. Specifically, the axle housing 10 has a base member 91 and two cylindrical members 93R, 93L. The base member 91 is formed in a frame shape (endless shape), and has a housing chamber for housing the differential gear 14 therein. The two tubular members 93R and 93L extend from the base member 91 in opposite directions to each other in the vehicle width direction. Specifically, the tubular member 93R extends from the base member 91 in the Y direction, and the tubular member 93L extends from the base member 91 in the direction opposite to the Y direction. The two cylindrical members 93R and 93L are fixed to the base member 91 by a bonding member such as a screw or a bolt, welding, or the like. Each of the two tubular members 93R and 93L is provided with a storage chamber for storing the drive shafts 15L and 15R. Further, the mechanism of fixing the components of the axle housing 10 to each other is not limited to the above. The axle housing 10 is also referred to as a housing, rigid axle.

In addition, the base member 91 has two mating surfaces 91a, 91 b. The mating surface 91a is an end surface at the front in the X direction and faces the X direction. The engagement surface 91b is a rear end surface opposite to the X direction, and faces in the opposite direction to the X direction. The mating faces 91a, 91b are planar.

The drive shafts 15L, 15R extend in the Y direction, i.e., the vehicle width direction. The drive shafts 15L, 15R are arranged on a straight line with a gap in the Y direction (vehicle width direction). A differential gear 14 is disposed between the drive shafts 15L, 15R. The drive shafts 15L, 15R are housed in the axle case 10, and are supported by the axle case 10 via bearings so as to be rotatable about the center axis Ax 1. The center axis Ax1 is along the Y direction, i.e., the vehicle width direction. The center axis Ax1 is an example of a first center axis.

The drive housing 101 of the drive unit 100 has a base part 102 and a cover part 94. The base member 102 has a mating surface 102 a. The mating surface 102a is a rear end surface opposite to the X direction, and faces in the opposite direction to the X direction. The mating surface 102a overlaps the mating surface 91a of the axle housing 10. The base member 102 is fixed to the base member 91 by a joint member such as a screw or a bolt in a state where the base member 91 is overlapped with the base member 91 on the front side, which is the X direction side, of the base member 91 of the axle housing 10. The base member 102 is provided with a part of a housing chamber for housing the connection mechanism 12 and a part of a housing chamber for housing the differential gear 14 and the like. The cover member 94 is fixed to the base member 102 by a joint member such as a screw or a bolt in a state where the cover member overlaps the base member 102 on the X-direction side, i.e., the front side, of the base member 102. A storage chamber for storing the coupling mechanism 12 is provided between the base member 102 and the cover member 94.

The motor 11 has a motor housing 11a and a motor shaft 11 b. The motor housing 11a is supported (fixed) to the axle housing 10. Specifically, the motor housing 11a is detachably attached to the cover member 94 by screws or the like. That is, the motor 11 is detachably mounted to the axle housing 10 via the cover member 94 and the base 101 member. A part of the motor shaft 11b, a rotor (not shown) that rotates integrally with the motor shaft 11b, and a stator (not shown) that surrounds the outer periphery of the rotor are housed in the motor case 11 a.

The motor shaft 11b is supported by the motor housing 11a so as to be rotatable about the center axis Ax 2. The motor shaft 11b enters the opening 94a provided in the cover member 94 and extends inside the cover member 94. That is, the motor shaft 11b penetrates the opening 94 a. The center axis Ax2 is along the X direction (vehicle front-rear direction), i.e., the direction orthogonal to (intersecting) the axial direction of the center axis Ax 1. For example, the center axis Ax2 is along the vehicle front-rear direction. The portion of the motor shaft 11B protruding from the motor housing 11a is rotatably supported by two bearings B1 and B2. The two bearings B1 and B2 are arranged at intervals in the X direction. The two bearings B1, B2 are supported by the cover member 94. That is, the portion of the motor shaft 11B protruding from the motor housing 11a is rotatably supported by the cover member 94 via two bearings B1 and B2.

The motor 11 supplies electric power to apply a torque (motive power) around the central axis Ax2 to the motor shaft 11 b. That is, the motor shaft 11b outputs power. The power output from the motor shaft 11b of the motor 11 is input to the transmission 13 via the connection mechanism 12.

The coupling mechanism 12 has a single gear position 70. The gear stage 70 has a first gear 71, a second gear 72, and a transmission shaft 73. The coupling mechanism 12 is a speed reduction mechanism that reduces the speed of rotation input to the first gear 71 and outputs the rotation from the second gear 72. The connection mechanism 12 may be a speed increasing mechanism that increases the speed of the rotation input to the first gear 71 and outputs the rotation from the second gear 72, or may be a mechanism that neither reduces nor increases the speed. The connection mechanism 12 is also referred to as a coupling mechanism or a power transmission mechanism. The connecting mechanism 12 is an example of the second gear mechanism.

The transmission shaft 73 is disposed in parallel to and apart from the motor shaft 11b of the motor 11. The transmission shaft 73 is supported by the drive housing 101 so as to be rotatable about the central axis Ax 3. The central axis Ax3 is parallel to the central axis Ax2 and is aligned at a spacing from the central axis Ax 2. Specifically, the transmission shaft 73 is rotatably supported by the two support portions 101a and 101B of the drive case 101 via the two bearings B3 and B4. The two support portions 101a and 101b are arranged at intervals in the X direction. Therefore, the two bearings B3 and B4 are also arranged at intervals in the X direction. Support 101a and bearing B3 are located in the X direction of support 101B and bearing B4. The two support portions 101a and 101B are portions of a cylindrical surface overlapping the bearings B3 and B4 of the drive case 101, respectively. The support portion 101a is included in the cover member 94, and the support portion 101b is included in the base member 102. Therefore, the bearing B3 is provided to the cover member 94, and the bearing B4 is provided to the base member 102. The bearings B3 and B4 are examples of bearings for the transmission shaft.

The first gear 71 is fixed to the motor shaft 11b of the motor 11 and rotates around the central axis Ax2 integrally with the motor shaft 11 b.

The second gear 72 is fixed to the transmission shaft 73 and rotates around the central axis Ax3 integrally with the transmission shaft 73. The second gear 72 is provided between the two support portions 101a, 101b of the drive housing 101 of the transmission shaft 73.

The transmission case 201 of the transmission unit 200 includes a differential case 202 and a transmission case 24 described later. The transmission housing 24 is also referred to as a transmission case.

The differential housing 202 has two mating faces 202a, 202 b. The mating surface 202a is an end surface in front in the X direction and faces the X direction. The mating surface 202a overlaps the mating surface 91b of the axle housing 10. The mating surface 202b is a rear end surface opposite to the X direction, and faces in the opposite direction to the X direction. Mating face 202b is contained within a bulkhead 202c of differential housing 202. The mating faces 202a, 202b are planar. The mating face 202b is an example of a first mating face.

The differential case 202 is fixed to the base member 91 by a joint member such as a screw or a bolt in a state where the base member 91 is overlapped with the rear side opposite to the X direction of the base member 91 of the axle case 10. The differential case 202 is provided with a part of a housing chamber that houses the differential gear 14 and the like.

The transmission 13 is disposed on the opposite side of the motor 11 from the central axis Ax1 of rotation of the ring gear 52 and the drive shafts 15L, 15R. That is, the central shaft Ax1 is located between the motor 11 and the transmission 13. More specifically, the motor 11 and the transmission 13 are arranged in the vehicle front-rear direction with the center axis Ax1 in between.

The transmission 13 has a gear mechanism 29 and a transmission housing 24. The gear mechanism 29 has an input shaft 21, an output shaft 22, a plurality of gear positions 30, and a gear connecting mechanism 23. The gear mechanism 29 is housed in the transmission case 24. The transmission 13 is configured to decelerate the rotation (power) input to the input shaft 21 and accelerate the rotation (power) input to the input shaft 21, as an example. The transmission 13 may be configured to perform only speed reduction or only speed increase. That is, the transmission 13 may be configured to perform at least one of deceleration and acceleration. The gear mechanism 29 is an example of a first gear mechanism, and the transmission case 24 is an example of a gear case.

The transmission housing 24 has a mating face 24 a. The mating surface 24a is an end surface at the front in the X direction and faces the X direction. The mating face 24a overlaps the mating face 202b of the differential case 202. The mating face 24a is an example of a second mating face.

The transmission housing 24 is supported (fixed) to the axle housing 10. In detail, the transmission case 24 is supported (fixed) to the axle housing 10 via the differential case 202. The transmission case 24 is detachably attached to the differential case 202 by screws or the like. That is, the transmission 13 is detachably mounted to the axle housing 10.

In addition, the transmission case 24 is constituted by a plurality of members. Specifically, the transmission case 24 has: a first housing member 25 including a mating face 24a, and a second housing member 26 located on the side of the first housing member 25 in the direction opposite to the X direction and fixed to the first housing member 25. The first housing member 25 is formed in a cylindrical shape with both ends open. The first housing part 25 has a fitting surface 25a in addition to the fitting surface 24 a. The mating surface 25a is a rear end surface opposite to the X direction, and faces in the opposite direction to the X direction. The mating face 25a is a flat face. The first housing part 25 houses at least one gear position 30. The second housing member 26 is formed in a bottomed cylindrical shape that is open in the X direction. The second housing member 26 has a mating face 26 a. The mating surface 26a is an end surface at the front in the X direction and faces the X direction. The mating face 26a is a flat face. The mating face 26a overlaps the mating face 25a of the first housing member 25. The second housing member 26 houses the parking lock gear 17.

The input shaft 21 and the output shaft 22 are disposed in parallel and separated from each other. The input shaft 21 is supported by the transmission housing 201 so as to be rotatable about a center axis Ax 3. The central axis Ax3 is along a direction orthogonal to (intersecting) the central axis Ax 1. Specifically, the input shaft 21 is rotatably supported by the support portions 201a and 201B of the transmission housing 201 via two bearings B5 and B6. The support portions 201a and 201b are arranged at intervals in the X direction. Therefore, the two bearings B5 and B6 are also arranged at intervals in the X direction. Support portion 201a and bearing B5 are located in the X direction of support portion 201B and bearing B6. The two support portions 201a and 201B are portions of a cylindrical surface that overlap with the bearings B5 and B6 of the transmission case 201, respectively. The support portion 201a is included in the differential case 202, and the support portion 201b is included in the transmission case 24. Thus, bearing B5 is disposed in differential housing 202 and bearing B6 is disposed in transmission housing 24. Thus, the two bearings B5, B6 are supported by the transmission housing 201. That is, the input shaft 21 is rotatably supported by the transmission housing 201 via two bearings B5 and B6. More specifically, the bearing B5 is fitted into an opening 202d provided in a partition wall 202c of the differential case 202 and supported by the differential case 202. The bearing B6 is supported by the transmission housing 24. The input shaft 21 enters the opening 202d and penetrates the opening 202 d. The bearings B5 and B6 are examples of bearings for the input shaft.

The output shaft 22 is supported by the transmission case 24 so as to be rotatable about a central axis Ax 4. The central axis Ax4 is along a direction orthogonal to (intersecting) the central axis Ax 1. The central axis Ax4 is parallel to the central axis Ax3 and is aligned at a spacing from the central axis Ax 3. Specifically, the output shaft 22 is rotatably supported by two bearings B7 and B8. The two bearings B7 and B8 are arranged at intervals in the X direction. The bearing B7 is located in the X direction of the bearing B8. The bearing B7 is one of the two bearings B7 and B8 that is close to the differential gear 14. Two bearings B7, B8 are supported by the transmission housing 201. That is, the input shaft 21 is rotatably supported by the transmission housing 201 via two bearings B7 and B8. More specifically, the bearing B7 is fitted into an opening 202e provided in a partition wall 202c of the differential case 202 and supported by the differential case 202. The bearing B8 is supported by the transmission housing 24. The output shaft 22 enters the opening 202e and penetrates the opening 202 e. Here, the opening 202d and the opening 202e are separated from each other. The opening 202d and the opening 202e are separated from the opening 94 a. The central axes Ax 1-Ax 4 are also referred to as rotation axes. The bearings B7 and B8 are examples of bearings for the output shaft.

The power of the motor 11 is input to the input shaft 21 via the connection mechanism 12, and the input shaft 21 is rotated by the power.

Each of the plurality of shift positions 30 is a constantly engaged shift position, and is provided across the input shaft 21 and the output shaft 22. The gear ratios of the plurality of gears 30 (gear ratio, the rotation speed of the input shaft 21/the rotation speed of the output shaft 22) are different from each other. Gear 30 is also referred to as a gear pair. The transmission ratio is also referred to as the variator ratio.

The plurality of gear positions 30 includes a first gear position 31 and a second gear position 32. The first speed range 31 and the second speed range 32 are arranged at an interval from each other in the axial direction of the central axis Ax2 of the input shaft 21. The gear ratio of second speed stage 32 is relatively small compared to the gear ratio of first speed stage 31. The first gear 31 constitutes a speed reduction mechanism 41 by the input shaft 21 and the output shaft 22. The speed reduction mechanism 41 reduces the speed of the rotation input to the input shaft 21 and outputs the rotation from the output shaft 22. The second-speed gear 32 constitutes a speed increasing mechanism 42 by the input shaft 21 and the output shaft 22. The speed increasing mechanism 42 increases the speed of the rotation input to the input shaft 21 and outputs the rotation from the output shaft 22. The reduction mechanism 41 and the speed-up mechanism 42 are supported by the axle case 10 via the transmission case 24 and the differential case 202. The first speed step 31 is also referred to as a low speed gear, and the second speed step 32 is also referred to as a high speed gear. Further, the structure of the plurality of shift stages 30 is not limited to the above structure. For example, both first gear position 31 and second gear position 32 may be speed reduction mechanisms, and both first gear position 31 and second gear position 32 may be speed increase mechanisms.

The first speed stage 31 includes a drive gear 33 and a driven gear 34 that mesh with each other, and the second speed stage 32 includes a drive gear 35 and a driven gear 36 that mesh with each other. That is, the transmission 13 has a plurality of drive gears 33, 35 and a plurality of driven gears 34, 36. The drive gear 33 is an example of an input gear, and the driven gear 34 is an example of an output gear.

The drive gears 33, 35 are fixed to the input shaft 21 and rotate around the central axis Ax3 integrally with the input shaft 21. That is, the drive gears 33, 35 are provided on the input shaft 21. The drive gears 33, 35 are disposed between the two support portions 201a, 201b of the transmission housing 201 of the input shaft 21.

The driven gears 34 and 36 are supported by the output shaft 22 via bearings (not shown) so as to be rotatable relative to the output shaft 22 and rotate around a central axis Ax 4. That is, the driven gears 34 and 36 are provided on the output shaft 22. The driven gears 34 and 36 can idle with respect to the output shaft 22 in a state where they are not connected to the output shaft 22 by the gear connection mechanism 23. The driven gears 34 and 36 restrict the movement of the center axis Ax4 in the axial direction.

Further, a final gear 38 is provided on the output shaft 22. The final drive gear 38 is fixed to the output shaft 22 and rotates around the central axis Ax4 integrally with the output shaft 22.

The gear connection mechanism 23 is provided between the driven gear 34 of the first speed stage 31 and the driven gear 36 of the second speed stage 32. The gear coupling mechanism 23 can selectively switch between a coupling state (coupling state) and a decoupling state (non-coupling state) of the output shaft 22 and the driven gears 34 and 36 of the first and second speed stages 31 and 32. That is, the gear connection mechanism 23 switches the transmission state of rotation between the output shaft 22 and the driven gears 34 and 36. The gear connection mechanism 23 is also referred to as a switching mechanism or a selection mechanism.

The gear connection mechanism 23 has a hub 43 and a sleeve 44. The hub 43 is coupled to the output shaft 22 and rotates around the central axis Ax4 integrally with the output shaft 22. The sleeve 44 is coupled to the hub 43 by spline coupling, rotates around the central axis Ax4 integrally with the hub 43, and is movable relative to the hub 43 in the axial direction of the output shaft 22. That is, the sleeve 44 rotates around the central axis Ax4 integrally with the output shaft 22 and is movable in the axial direction of the output shaft 22 relative to the output shaft 22.

The sleeve 44 is configured to be movable between a first coupling position to be coupled to the driven gear 34, a second coupling position to be coupled to the driven gear 36, and a neutral position (fig. 2) between the first coupling position and the second coupling position. The sleeve 44 is selectively positioned at any one of a first coupling position with the driven gear 34, a second coupling position with the driven gear 36, and a neutral position by an actuator and a moving mechanism, which are not shown. In a state where the sleeve 44 is located at the first coupling position with the driven gear 34, the output shaft 22 and the driven gear 34 are rotatable integrally. In this case, a transmission path of the first speed rotation is formed from the motor shaft 11b of the motor 11 to the coupling mechanism 12, the drive gear 33, the driven gear 34, the output shaft 22, the final gear 38, the differential gear 14, and the drive shafts 15L, 15R.

In addition, the output shaft 22 and the driven gear 36 are rotatable integrally in a state where the sleeve 44 is located at the second coupling position with the driven gear 36. In this case, a second-speed rotation transmission path is formed from the motor shaft 11b of the motor 11 to the coupling mechanism 12, the drive gear 35, the driven gear 36, the output shaft 22, the final gear 38, the differential gear 14, and the drive shafts 15L and 15R.

In a state where the sleeve 44 is located at the neutral position, the driven gears 34 and 36 can idle with respect to the output shaft 22.

The differential gear 14 includes a differential gear case 51, a ring gear 52, and a differential mechanism (not shown).

The differential gear case 51 is housed in the differential case 202. The differential gear case 51 is supported by the differential case 202 via bearings B9, B10 so as to be rotatable about the central axis Ax 1. In such a structure, the differential gear 14 is rotatably supported by the axle housing 10 via the transmission housing 201.

The ring gear 52 is fixed to the differential gear case 51, and rotates around the central axis Ax1 integrally with the differential gear case 51. That is, the ring gear 52 is rotatably supported about the central axis Ax1 by the differential case 202 via the bearing B7. Further, the ring gear 52 meshes with the final gear 38, and power is transmitted from the final gear 38. The final gear 38 and the ring gear 52 constitute a reduction gear ratio (so-called final reduction ratio).

The differential mechanism is housed in a differential gear case 51. The differential mechanism has a pinion shaft, two pinion gears, and two side gears. The pinion shaft extends in a direction orthogonal to the central axis Ax 1. The pinion shaft is supported by the differential gear case 51. The pinion gear is supported by the pinion shaft so as to be rotatable about the pinion shaft. The pinion shaft and the pinion gear rotate around the central axis Ax1 integrally with the differential gear case 51. The two side gears are respectively engaged with the two pinions in a state of being fixed to end portions of the two drive shafts 15L, 15R.

In the differential gear 14 configured as described above, when the ring gear 52 rotates, the differential gear case 51 rotates integrally with the pinion shaft. The pinion shaft revolves the pinion gear around the central axis Ax 1. Thereby, the side gears rotate around the central axis Ax1, and the drive shafts 15L, 15R rotate. When the side gears are rotated differentially, the pinion gears rotate on their own axes about the pinion shaft, thereby absorbing the differential rotation.

The transmission unit 200 having the above-described structure is configured by combining a plurality of units. In detail, the transmission unit 200 has a differential unit 203 and a gear unit 204.

The differential unit 203 has the differential gear 14, and the differential case 202. The gear unit 204 has the transmission 13 (the speed reducing mechanism 41, the speed increasing mechanism 42, the transmission case 24). The gear unit 204 is detachably attached to the differential unit 203.

The transmission shaft 73 is disposed on the same straight line as the input shaft 21 of the transmission 13 and is coupled to each other by a coupling portion 80. The transmission shaft 73, the input shaft 21, and the coupling portion 80 constitute a through drive shaft 81 that transmits power between the motor 11 and the transmission 13. In other words, the transmission shaft 73, the input shaft 21, and the coupling portion 80 form a through drive shaft 81. The through drive shaft 81 is rotatable about a center axis Ax3, extends from an X direction side (front side) of the axle housing 10 to an opposite side (rear side) in the X direction, and transmits power output from the motor shaft 11 b. The through drive shaft 81 is housed in the axle case 10, and is supported by the axle case 10 via bearings B3 to B6 so as to be rotatable about the central axis Ax 3. The through drive shaft 81 is also referred to as a coupling shaft. One of the transmission shaft 73 and the input shaft 21 is also referred to as a first portion, and the other is also referred to as a second portion.

The through drive shaft 81 extends in the X direction, i.e., the vehicle front-rear direction, at a position apart from the drive shaft 15R (the center axis Ax1), specifically, above the center axis Ax1 in the Z direction. Therefore, the through drive shaft 81 overlaps (intersects) the central axis Ax1 in plan view. The through drive shaft 81 may be provided above the drive shaft 15L and the differential gear 14, or may be provided below the drive shaft 15R, the drive shaft 15L and the differential gear 14.

The coupling portion 80 can separately couple the transmission shaft 73 and the input shaft 21. The joint 80 is received in the differential case 202. The joint 80 is located in the vicinity of the drive gear 33, among the second gear 72 of the connecting mechanism 12 and the drive gear 33 of the reduction mechanism 41 of the transmission 13. Coupling portion 80 is located rearward of drive shaft 15R in plan view. The position of the joint 80 is not limited to the above.

The coupling portion 80 spline-couples the transmission shaft 73 to the input shaft 21, for example. Specifically, the coupling portion 80 includes a male spline portion 80a provided on the input shaft 21, and a female spline portion 80b provided on the transmission shaft 73 and spline-coupled to the male spline portion 80 a. In such a configuration, the transmission shaft 73 and the input shaft 21 can be separated from each other in the axial direction of the central axis Ax3, the transmission shaft 73 and the input shaft 21 can be separated from each other, and the transmission shaft 73 and the input shaft 21 can be coupled to each other in the axial direction of the central axis Ax3 by bringing the transmission shaft 73 and the input shaft 21 closer to each other in the axial direction. The coupling portion 80 may be formed by coupling members such as screws and bolts so that the transmission shaft 73 and the input shaft 21 can be detachably coupled.

In the present embodiment, when the distance between the two portions 73a and 73B (the distance along the axial direction of the central axis Ax 3) supported by the two support portions 101a and 101B of the drive housing 101 of the transmission shaft 73 via the two bearings B3 and B4 and the distance between the two portions 21a and 21B (the distance along the axial direction of the central axis Ax 3) supported by the two support portions 201a and 201B of the transmission housing 201 of the input shaft 21 via the two bearings B3 and B4 are set as the first distances, the first distance of one of the input shafts 21 is longer than the first distance of the transmission shaft 73. The portions 73a and 73B of the transmission shaft 73 are cylindrical surfaces overlapping the bearings B3 and B4, respectively, and the portions 21a and 21B of the input shaft 21 are cylindrical surfaces overlapping the bearings B5 and B6, respectively. The first distance of one of the transmission shafts 73 may be longer than the first distance of the input shaft 21.

The parking brake 16 and the parking lock gear 17 are connected to an output shaft 22 of the transmission 13.

In the present embodiment, the motor 11 and the transmission 13 (the speed reduction mechanism 41 and the speed increase mechanism 42) are disposed on opposite sides of the central axis Ax1 of rotation of the ring gear 52 and the drive shafts 15L and 15R. That is, the central axis Ax1 is located between the motor 11 and the transmission 13 (the speed reducing mechanism 41 and the speed increasing mechanism 42). More specifically, the motor 11 and the transmission 13 (the speed reduction mechanism 41 and the speed increase mechanism 42) are arranged in the vehicle front-rear direction with the center axis Ax1 in between.

In the electric drive device 1 for a vehicle having the above configuration, the power output from the motor shaft 11b of the motor 11 is input to the input shaft 21 of the transmission 13 via the connection mechanism 12. The power input to the transmission 13 is input to the ring gear 52 of the differential gear 14 via one selected from the plurality of gear positions 30 (the first gear position 31 or the second gear position 32). The power input to the ring gear 52 is input to the drive shafts 15L, 15R via the differential mechanism.

As described above, in the present embodiment, the electric drive device 1 for a vehicle includes: the axle housing 10, the drive shafts 15L, 15R, the motor 11, the through drive shaft 81, the speed reducing mechanism 41 and the speed increasing mechanism 42 (first gear mechanism), the differential gear 14, the drive unit 100, and the power transmission unit 200. The drive shafts 15L, 15R are housed in the axle case 10 and are rotatable about a center axis Ax1 (first center axis). The motor 11 is located on the X direction (first direction) side with respect to the axle housing 10, which intersects the axial direction of the central axis Ax 1. The motor 11 has a motor shaft 11b that rotates about a central axis Ax2 (second central axis) along the X direction. The through drive shaft 81 includes: the transmission shaft 73, at least a portion of which is located on the X direction side with respect to the axle housing 10 and to which power is input from the motor shaft 11b, the input shaft 21, at least a portion of which is located on the opposite direction side with respect to the X direction with respect to the axle housing 10, and the coupling portion 80 that couples the transmission shaft 73 and the input shaft 21 are rotatable about a central axis Ax3 (third central axis) along the X direction. The speed reducing mechanism 41 and the speed increasing mechanism 42 include: the power transmission device includes an input shaft 21, an output shaft 22 rotatable about a central axis Ax4 (fourth central axis) parallel to the central axis Ax3 (third central axis) and arranged at an interval from the central axis Ax3, a plurality of drive gears 33, 35 and driven gears 34, 36 (gears) interposed between the input shaft 21 and the output shaft 22 and transmitting power. The differential gear 14 is housed in the axle case 10, is coupled to the drive shafts 15L, 15R and the output shaft 22, and transmits power from the output shaft 22 to the drive shafts 15L, 15R. The drive unit 100 is detachably mounted to the axle housing 10 and extends in the X direction from the axle housing 10. The transmission unit 200 is detachably mounted to the axle housing 10, and extends from the axle housing 10 in the direction opposite to the X direction. The drive unit 100 has a motor 11 and a transmission shaft 73. The transmission unit 200 has a differential unit 203 and a gear unit 204. The differential gear unit 203 has a differential gear 14; and a differential case 202 located on the opposite direction side of the X direction with respect to the axle housing 10, having a mating face 202b (first mating face) facing the opposite direction of the X direction, and receiving the differential gear 14. The gear unit 204 includes: a speed reduction mechanism 41 and a speed increase mechanism 42; and a transmission case 24 (gear case) which is located on the opposite side of the differential case 202 in the X direction, has an engaging surface 24a (second engaging surface) that engages with the engaging surface 202b, houses the speed reducing mechanism 41 and the speed increasing mechanism 42, and is detachably attached to the differential unit 203.

According to such a configuration, even when there are a plurality of types of gear units 204, for example, the differential unit 203 having the same configuration can be used for the gear units 204 of these plurality of specifications. That is, the differential case 202 of the differential unit 203 does not need to be changed. Therefore, it is possible to suppress an increase in cost of the electric drive device 1 for a vehicle, as compared with a case where the entire transmission housing 201 of the transmission unit 200 is changed for each of the gear units 204 of a plurality of specifications. In addition, replacement of the gear unit 204 is easy. That is, the problem of easy replacement of the gear unit 204 can be solved.

In the present embodiment, the differential unit 203 is supported by the differential case 202, and includes a bearing B7 (output shaft bearing) that rotatably supports the output shaft 22.

With this configuration, the differential gear unit 203 and the gear unit 204 can be divided while maintaining the meshing state of the differential gear 14.

In the present embodiment, the differential gear unit 203 is supported by the differential case 202, and includes a bearing B5 (input shaft bearing) that rotatably supports the through drive shaft 81.

With this structure, the structure for supporting the bearing B5 (partition wall 202c) and the structure for supporting the bearing B7 (partition wall 202c) can be shared.

In the present embodiment, the electric drive device 1 for a vehicle includes the through drive shaft 81 and the drive unit 100. The through drive shaft 81 includes a transmission shaft 73 at least a part of which is located on the X direction side with respect to the axle housing 10 and to which power is input from the motor shaft 11b, an input shaft 21 at least a part of which is located on the opposite direction side of the X direction with respect to the axle housing 10, and a coupling portion 80 that couples the transmission shaft 73 and the input shaft 21, and is rotatable about a central axis Ax3 (third central axis) in the X direction. The drive unit 100 includes a motor 11 and a transmission shaft 73, is detachably attached to the axle housing 10, and extends in the X direction from the axle housing 10.

With this configuration, the drive unit 100 can be attached to and detached from the axle housing 10.

In the present embodiment, the drive unit 100 includes a connection mechanism 12 (second gear mechanism), and the connection mechanism 12 (second gear mechanism) includes: a first gear 71 rotating integrally with the motor shaft 11b, a transmission shaft 73, and a second gear 72 transmitting power from the first gear 71 and rotating integrally with the transmission shaft 73.

With this configuration, the degree of freedom in the arrangement of the motor 11 is greater than that in a configuration in which the motor shaft 11b and the input shaft 21 are coaxially aligned and coupled.

In the present embodiment, the coupling portion 80 includes: a male spline portion 80a provided on one of the transmission shaft 73 and the input shaft 21 (the input shaft 21 as an example), and a female spline portion 80b provided on the other of the transmission shaft 73 and the input shaft 21 (the transmission shaft 73 as an example) and spline-coupled to the male spline portion 80 a.

With this configuration, the transmission shaft 73 and the input shaft 21 can be coupled relatively easily.

In the present embodiment, the motor 11 and the transmission 13 are mounted to the axle housing 10 independently of each other.

According to such a configuration, for example, the motor 11 can be attached to and detached from the axle housing 10 independently of the transmission 13, and therefore, replacement of the motor 11 and the transmission 13 is easier than a configuration in which the motor is attached to the axle housing via the transmission. Further, by unifying the mounting portions (mounting surfaces) of the plurality of motors 11 different in specification (performance) for the axle housing 10, it is possible to mount any of the motors 11 to the axle housing 10. Further, by unifying the mounting portions (mounting surfaces) of the plurality of transmissions 13 different in specification (performance) for the axle case 10, it is possible to mount any of the transmissions 13 to the axle case 10. Therefore, the number of combinations of the motor 11 and the transmission 13 is easily increased.

In the present embodiment, the motor 11 and the transmission 13 are located on opposite sides of the axle housing 10.

According to such a configuration, for example, compared to a configuration in which the motor and the transmission are located on the same side with respect to the axle housing 10, a working space for replacing the motor 11 and the transmission 13 is easily available, and therefore, replacement of the motor 11 and the transmission 13 is easily performed. In addition, the weight balance of the electric drive device 1 for a vehicle is improved.

Further, according to the above configuration, the opening 94a into which the motor shaft 11b of the motor 11 is inserted and the openings 202d and 202e into which the input shaft 21 and the output shaft 22 of the transmission 13 are inserted are easily located at separate positions. Therefore, it is easy to suppress the decrease in strength and rigidity of the electric drive device 1 for a vehicle.

In addition, in the present embodiment, since the openings 94a, 202d, and 202e are separated from each other, it is easier to suppress a decrease in strength and rigidity of the electric drive device 1 for a vehicle, as compared with a configuration in which the openings 94a, 202d, and 202e are formed as one opening.

In the present embodiment, the electric drive device 1 for a vehicle includes, for example, a through drive shaft 81. The through drive shaft 81 includes a transmission shaft 73 for transmitting power from the motor 11, an input shaft 21 for transmitting power from the transmission shaft 73, and a coupling portion 80 for detachably coupling the transmission shaft 73 and the input shaft 21, and transmits power between the motor 11 and the transmission 13.

With this configuration, the through drive shaft 81 can be separated into the transmission shaft 73 and the input shaft 21, and therefore, the motor 11 and the transmission 13 can be easily replaced.

< second embodiment >

Fig. 3 is an exemplary diagram showing a schematic configuration of the electric drive device 1 for a vehicle according to the second embodiment.

The joint 80 of the present embodiment is different from the first embodiment. The coupling portion 80 of the present embodiment is housed in the drive case 101. The male spline portion 80a is provided on the transmission shaft 73, and the female spline portion 80b is provided on the input shaft 21.

The drive unit 100 further includes a bearing B11 that rotatably supports the coupling portion 80. The bearing B11 supports the outer periphery 80c of the female spline portion 80B provided in the input shaft 21. The bearing B11 is supported by a support portion 101c provided in the drive case 101. Specifically, the support portion 101c is provided on the base member 102. The bearing B11 is different from the bearings B3 to B6. The outer diameter of bearing B11 is smaller than the outer diameters of bearings B3-B6. The bearing B11 is an example of a joint bearing.

In the present embodiment, as in the first embodiment, when the distance between the two portions 73a and 73b of the transmission shaft 73 supported by the two support portions 101a and 101b of the driven housing 101 (the distance along the axial direction of the central axis Ax 3) and the distance between the two portions 21a and 21b of the input shaft 21 supported by the two support portions 201a and 201b of the driven housing 201 (the distance along the axial direction of the central axis Ax 3) are respectively set as the first distance, the first distance on the one side of the input shaft 21 is longer than the first distance on the transmission shaft 73. The input shaft 21 extends across the central axis Ax1 toward the transmission shaft 73. In other words, the input shaft 21 protrudes from the transmission housing 201 toward the input shaft 21. That is, the input shaft 21 intersects (is orthogonal to as an example) the central axis Ax1 with a line of sight viewed from a direction (for example, the Z direction) orthogonal to the axial direction of the central axis Ax1 and the axial direction of the central axis Ax 3. The coupling portion 80 is housed in the drive case 101. The first distance of the transmission shaft 73 may be longer than the first distance of the input shaft 21, and the transmission shaft 73 may extend across the center axis Ax1 toward the input shaft 21. In this case, the coupling portion 80 is housed in the transmission case 201.

As described above, in the present embodiment, the distance between the two portions 73a and 73b of the transmission shaft 73 supported by the two support portions 101a and 101b of the driven casing 101 and the distance between the two portions 21a and 21b of the input shaft 21 supported by the two support portions 201a and 201b of the driven casing 201 are respectively set as the first distance, the longer first distance of the input shaft 21 and the transmission shaft 73 is set as one shaft (the input shaft 21 as an example), the shorter first distance of the input shaft 21 and the transmission shaft 73 is set as the other shaft (the transmission shaft 73 as an example), the one supporting shaft (the input shaft 21 as an example) of the driving casing 101 and the transmission casing 201 is set as one casing (the transmission casing 201 as an example), the other supporting shaft (the transmission casing 201 as an example, when one of the transmission shafts 73) is the other housing (for example, the drive housing 101), the one shaft (for example, the input shaft 21) extends toward the other shaft (for example, the transmission shaft 73) across the center axis Ax1, and the coupling portion 80 is housed in the drive housing 101.

According to such a configuration, compared to a configuration in which the other shaft (for example, the transmission shaft 73) having the short first distance extends toward the one shaft (for example, the input shaft 21) having the long first distance so as to cross the central axis Ax1 and the coupling portion 80 is housed in the one housing (for example, the transmission housing 201), it is easy to suppress the swing of the end portion of the one shaft (for example, the input shaft 21) having the long first distance on the side of the coupling portion 80. That is, the effect of suppressing the hunting generated in the coupling portion 80 by the rotation of the penetration drive shaft 81 is high. Therefore, the occurrence of vibration of the electric drive device 1 for a vehicle, which penetrates the drive shaft 81, can be easily suppressed.

In the present embodiment, the drive unit 100 includes the second gear 72 mechanism having the single shift stage 70, and the single shift stage 70 includes the first gear 71 that rotates integrally with the motor shaft 11b, the transmission shaft 73, and the second gear 72 that transmits power from the first gear 71 and rotates integrally with the transmission shaft 73. The gear mechanism 29 has a plurality of gear positions 30. One shaft is the input shaft 21 and one housing is the transmission housing 201.

With this structure, the weight balance in the vehicle front-rear direction is improved.

In the present embodiment, the plurality of shift positions 30 of the gear mechanism 29 (first gear mechanism) includes a plurality of drive gears 33, 35 provided on the input shaft 21; and a plurality of driven gears 34, 36 that transmit power from the plurality of drive gears 33, 35 and are provided on the output shaft 22. The electric drive device 1 for a vehicle has a plurality of drive gears 33, 35 between two support portions 201a, 201b of a transmission housing 201 of an input shaft 21. The electric drive device 1 for a vehicle has the second gear 72 between the two support portions 101a and 101b of the drive case 101 of the transmission shaft 73.

In the present embodiment, the coupling portion 80 is supported by another housing (for example, the drive housing 101).

With such a configuration, it is easier to suppress the swing of the end portion of the first long shaft (for example, the input shaft 21) on the coupling portion 80 side.

In the present embodiment, the coupling portion 80 includes a female spline portion 80B provided on one shaft (the input shaft 21, as an example) and a male spline portion 80a provided on the other shaft (the transmission shaft 73, as an example) and spline-coupled to the female spline portion 80B, and a bearing B11 (a coupling portion bearing) is provided between an outer periphery 80c of the female spline portion 80B and the other housing (the drive housing 101, as an example).

With such a configuration, it is easier to suppress the swing of the end portion of the first long shaft (for example, the input shaft 21) on the coupling portion 80 side.

In the present embodiment, the two support portions 101a and 101B of the drive case 101 support the transmission shaft 73 rotatably about the central axis Ax3 via bearings B3 and B4 (transmission shaft bearings), respectively. The input shaft 21 is rotatably supported around a central axis Ax3 by two support portions 201a and 201B of the transmission housing 201 via bearings B5 and B6 (input shaft bearings). The coupling portion 80 is supported by another housing (for example, the drive housing 101) via a bearing B11 (coupling portion bearing). The outer diameter of bearing B11 is smaller than the outer diameters of bearings B3, B4 and bearings B5, B6.

Since a load applied to the shaft support portion of the bearing B11 provided to suppress the swing is smaller than the bearings B3 and B4 and the bearings B5 and B6 provided to support the rotation of the transmission shaft 73 and the input shaft 21, the diameter of the bearing B11 can be reduced. This enables the size in the radial direction near the coupling portion 80 of the drive unit 100 to be reduced.

In the present embodiment, the drive unit 100 has a drive case 101 in which the motor 11 and the transmission shaft 73 are housed, and the coupling portion 80 is housed in the drive case 101.

With this configuration, the transmission shaft 73 penetrating the drive shaft 81 can be easily shortened. Therefore, the swing of the transmission shaft 73 is easily suppressed.

In the present embodiment, the electric drive device 1 for a vehicle includes a bearing B11 (a bearing for a coupling portion) that rotatably supports the coupling portion 80.

With this configuration, even if the distance between the coupling portion 80 and the bearing B5 supporting the input shaft 21 is relatively long, the swing of the end portion (tip end portion) of the input shaft 21 supported by the coupling portion 80 is easily suppressed. Further, the bearing B11 may be applied to the first embodiment.

In the present embodiment, the diameter of the bearing B11 (joint bearing) is smaller than the diameter of the bearing B5 (input shaft bearing).

With such a configuration, the arrangement space of the bearing B11 may be smaller than that in the case where the diameter of the bearing B11 is equal to or larger than that of the bearing B5.

In the present embodiment, the coupling portion 80 includes a male spline portion 80a provided on the transmission shaft 73 and a female spline portion 80b provided on the input shaft 21 and spline-coupled to the male spline portion 80 a.

With this configuration, the effect of preventing the input shaft 21 from wobbling is further enhanced.

The male spline portion 80a may be provided on the input shaft 21, the female spline portion 80B may be provided on the transmission shaft 73, and the female spline portion 80B of the transmission shaft 73 may be supported by the bearing B11. In this case, even in a state where the bearing B11 is provided, the input shaft 21 and the transmission shaft 73 can be easily coupled.

In the above embodiment, the motor 11 and the transmission 13 are located on the opposite sides of the axle housing 10, but the present invention is not limited to this. For example, the motor 11 and the transmission 13 may be located on the same side of the axle housing 10. In this case, the motor 11 and the transmission 13 may be arranged in the vehicle width direction or may be arranged in the vertical direction.

In the above embodiments, the first gear mechanism is the speed reduction mechanism 41 and the speed increase mechanism 42, but the present invention is not limited to this. For example, the first gear mechanism may be constituted by only one speed reduction mechanism 41 or only one speed increase mechanism 42. That is, the first gear mechanism may be configured such that the gear position 30 cannot be selected. The first gear mechanism may be configured to have the same rotational speed as the input shaft 21 and the output shaft 22, that is, may be configured not to perform speed reduction or speed increase.

The motor shaft 11b and the transmission shaft 73 may be not separate shafts but may be an integral shaft. That is, the motor shaft 11b and the transmission shaft 73 may be provided coaxially and integrally without passing through the shift position 70.

The differential gear 14 may be rotatably supported by the axle housing 10 without passing through the transmission housing 201.

While the embodiments of the present invention have been described above, the above embodiments are merely examples and are not intended to limit the scope of the present invention. The above-described new embodiments may be implemented in various forms, and various omissions, substitutions, and changes may be made without departing from the spirit of the invention. The above embodiments are included in the scope and gist of the invention, and are included in the invention described in the claims and equivalents thereof.

Description of reference numerals

1 … electric drive device for vehicle, 10 … axle housing, 11 … motor, 11b … motor shaft, 12 … connecting mechanism (second gear mechanism), 14 … differential gear, 15L, 15R … drive shaft, 21 … input shaft, 21a, 21b … portion, 22 … output shaft, 24 … transmission housing (gear housing), 24a … mating face (second mating face), 29 … gear mechanism (first gear mechanism), 30 … gear, 33, 35 … drive gear (gear), 34, 36 … driven gear (gear), 70 … gear, 71 … first gear, 72 … second gear, 73 … transmission shaft, 73a, 73b … portion, 80 … mating portion, 80a … spline portion, 80b … female spline portion, 80c … periphery, … peripheral portion, 3681 drive shaft, 100 … drive unit, 101a, 101b … drive housing, 101b … drive unit, 200 drive unit …, 201 … drive housing, 201a, 201B … bearing portion, 202 … differential housing, 202B … mating surface (first mating surface), 203 … differential unit, 204 … gear unit, Ax1 … center shaft (first center shaft), Ax2 … center shaft (second center shaft), Ax3 … center shaft (third center shaft), Ax4 … center shaft (fourth center shaft), B3, B4 … bearing (bearing for transmission shaft), B5, B6 … bearing (bearing for input shaft), B7 … bearing (bearing for output shaft), B11 … bearing (bearing for coupling portion).