阅读说明：本技术 车辆驱动装置 (Vehicle drive device ) 是由 安德瑞·彼丁 于 2019-06-11 设计创作，主要内容包括：本发明提供一种车辆驱动装置(100),具有：电动机(1),具有以上下方向的第1轴线(CL1)为中心旋转的转子(11)、第1旋转轴(13),沿第1轴线(CL1)延伸,在前端部具有第1齿轮(14),并能够与转子(11)一体旋转、左右一对第2旋转轴(21),分别沿上下方向的第2轴线(CL2)在左右方向相互分离地竖立设置,分别在前端部具有与第1齿轮(14)啮合的第2齿轮(22),并一体地设有蜗杆齿轮(23)、左右一对蜗轮(31),分别与左右一对蜗杆齿轮(23)啮合,能够以左右方向的第3轴线(CL3)为中心旋转；以及左右一对驱动轴(45),分别被输入来自左右一对蜗轮(31)的转矩。(The invention provides a vehicle driving device (100), comprising: a motor (1) having a rotor (11) that rotates about a vertical 1 st axis (CL1) and a1 st rotating shaft (13), extending along the 1 st axis (CL1), having a1 st gear (14) at a front end portion thereof, and being capable of rotating integrally with the rotor (11), and a pair of left and right 2 nd rotating shafts (21), wherein the 2 nd axes (CL2) along the vertical direction are vertically provided so as to be separated from each other in the left-right direction, and each of the front end portions thereof has a2 nd gear (22) that meshes with the 1 st gear (14), and a worm gear (23) and a pair of left and right worm gears (31) are integrally provided, and each of the two worm gears meshes with the pair of left and right worm gears (23), and is capable of rotating about a 3 rd axis (CL3) in the left-right; and a pair of left and right drive shafts (45) to which torque is input from the pair of left and right worm gears (31), respectively.)

1. A vehicle drive device is characterized by comprising:

a motor (1) having a rotor (11) that rotates about a vertical 1 st axis (CL1) and a stator (12) disposed around the rotor (11);

a1 st rotating shaft (13) that is provided so as to extend along the 1 st axis (CL1), has a1 st gear (14) at a distal end portion thereof, and is rotatable integrally with the rotor (11);

a pair of left and right 2-th rotary shafts (21) which are vertically provided so as to be separated from each other in the left-right direction along a pair of left and right 2-th axes (CL2) parallel to the 1-st axis (CL1), respectively, each of which has a 2-th gear (22) at a distal end portion thereof, which meshes with the 1-th gear (14), and each of which is integrally provided with a worm gear (23) that rotates about the 2-nd axis (CL 2);

a pair of left and right worm gears (31) that are provided so as to mesh with the worm gears (23) of the pair of left and right 2 nd rotating shafts (21), respectively, and that are rotatable about a 3 rd axis (CL3) in the left-right direction; and

the left and right drive shafts (45) are respectively inputted with torque from the left and right worm gears (31).

2. The vehicle drive device according to claim 1, characterized by further comprising:

a pair of left and right planetary gear mechanisms (4) which are respectively built in the pair of left and right worm gears (31) and transmit power from the pair of left and right worm gears (31) to the pair of left and right drive shafts (45), respectively;

and a speed difference absorbing device (101) that absorbs the speed difference between the pair of left and right drive shafts (45) when the vehicle is turning.

3. The vehicle drive apparatus according to claim 2,

the motor (1) is a1 st motor,

the pair of left and right planetary gear mechanisms (4) is a pair of left and right single pinion type 1 st planetary gear mechanisms, and includes: a pair of left and right ring gears (42) connected to the pair of left and right worm gears (31), a pair of left and right planetary carriers (44) connected to the pair of left and right drive shafts (45), and a pair of left and right sun gears (41),

the speed difference absorbing device (101) comprises: a2 nd electric motor (5) and a2 nd planetary gear mechanism (6) of a double pinion type interposed in series between the pair of left and right sun gears (41), and a control unit (8) for controlling the 2 nd electric motor (5).

4. The vehicle drive apparatus according to claim 3,

the 2 nd planetary gear mechanism (6) has: a ring gear (62) provided so as not to be rotatable, a carrier (65) connected to one of the pair of left and right sun gears (41), and a sun gear (61) connected to a rotating shaft (51a) of the 2 nd motor (5),

the number of teeth of the ring gear (62) of the 2 nd planetary gear mechanism (6) is 2 times the number of teeth of the sun gear (61) of the 2 nd planetary gear mechanism (6).

5. The vehicle drive apparatus according to claim 3 or 4, characterized by further comprising:

a vehicle speed detection unit (9a) that detects a vehicle speed; and

a steering angle detection unit (9b) for detecting a steering angle,

the control unit (8) calculates a target rotation speed difference (Δ N) between the pair of left and right drive shafts based on signals from the vehicle speed detection unit (9a) and the steering angle detection unit (9b), calculates a target rotation speed (Nm) of the 2 nd electric motor (5) corresponding to the target rotation speed difference (Δ N), and controls the 2 nd electric motor (5) such that the rotation speed of the 2 nd electric motor (5) becomes the target rotation speed (Nm).

6. The vehicle drive device according to any one of claims 1 to 5,

the left and right worm gears (31) are disposed below the left and right 2 nd gears (22), respectively.

7. The vehicle drive apparatus according to any one of claims 1 to 6,

the 1 st gear (14) and the 2 nd gear (22) comprise spur gears or helical gears.

Technical Field

The present invention relates to a vehicle drive device for driving a vehicle to travel by power of an electric motor.

Background

As such a device, a device is known in which a motor is disposed below a seat of a vehicle such that a rotation axis of the motor faces in an up-down direction, and torque of the motor is transmitted to a shaft extending in a horizontal direction via a pair of bevel gears. Such a device is described in patent document 1, for example. In the device described in patent document 1, a bevel gear is provided at an upper end portion of a shaft fitted to a central portion of a rotor of a motor, and the bevel gear meshes with a bevel gear provided at a distal end portion of a shaft in a horizontal direction.

However, in the device described in patent document 1, since the power of the motor is transmitted to the horizontal shaft via the pair of bevel gears, the diameter of the bevel gear needs to be increased in order to transmit a large torque to the horizontal shaft. As a result, the vehicle drive device is increased in size in the height direction, and it is difficult to dispose the vehicle drive device capable of transmitting a large torque in a predetermined space of the vehicle limited in the height direction.

Disclosure of Invention

A vehicle driving device according to an aspect of the present invention includes: a motor having a rotor that rotates about a1 st axis in a vertical direction and a stator disposed around the rotor; a1 st rotating shaft which is provided to extend along a1 st axis, has a1 st gear at a tip end portion, and is rotatable integrally with the rotor; a pair of right and left 2 nd rotating shafts which are vertically provided so as to be separated from each other in the right and left direction along a pair of right and left 2 nd axes parallel to the 1 st axis, respectively, and which have 2 nd gears meshing with the 1 st gear at front end portions thereof, respectively, and are integrally provided with worm gears which rotate about the 2 nd axes, respectively; a pair of left and right worm gears which are engaged with the worm gears of the pair of left and right 2 nd rotating shafts, respectively, and are rotatable around a 3 rd axis in the left-right direction; and a pair of left and right drive shafts to which torque from the pair of left and right worm gears is input, respectively.

Drawings

The objects, features and advantages of the present invention are further clarified by the following description of the embodiments in relation to the accompanying drawings.

Fig. 1 is a perspective view showing a main part structure of a vehicle driving device according to an embodiment of the present invention.

Fig. 2 is a frame diagram of the vehicle drive device of fig. 1.

Fig. 3 is a diagram showing a relationship between the target rotational speed difference of the left and right drive wheels and the target rotational speed difference of the power distribution motor in fig. 1.

Fig. 4A is a diagram showing a torque transmission path during straight traveling in the vehicle drive device according to the embodiment of the present invention.

Fig. 4B is a diagram showing a torque transmission path during turning in the vehicle driving device according to the embodiment of the present invention.

Fig. 5A is a diagram showing an example of an alignment chart during straight traveling in the vehicle driving device according to the embodiment of the present invention.

Fig. 5B is a diagram showing an example of a collinear chart during turning in the vehicle driving device according to the embodiment of the present invention.

Detailed Description

An embodiment of the present invention will be described below with reference to fig. 1 to 5B. Fig. 1 is a perspective view showing a main part structure of a vehicle driving device 100 according to an embodiment of the present invention. For example, when the vehicle is configured as a front-wheel drive vehicle, the vehicle drive device 100 is disposed between the left and right front wheels. For example, when the vehicle is configured as a rear-wheel drive vehicle, the vehicle drive device 100 is disposed between the left and right rear wheels. Hereinafter, the structure of each part of the vehicle drive device 100 will be described using the front-rear direction (vehicle longitudinal direction), the up-down direction (vehicle height direction), and the left-right direction (vehicle width direction) of the vehicle in a state where the vehicle drive device 100 is mounted on the vehicle. The front-back direction, the up-down direction, and the left-right direction are defined as shown in fig. 1.

Fig. 2 is a frame diagram of the vehicle drive device 100. As shown in fig. 1 and 2, the vehicle driving device 100 includes an electric motor 1 as an example of a rotating electric machine, and outputs a travel driving torque, which is a driving source of the electric motor 1, to driving wheels (front wheels or rear wheels). Therefore, vehicle drive device 100 is mounted on a vehicle having electric motor 1 as a travel drive source, such as an electric vehicle or a hybrid vehicle. The motor 1 can also be used as a generator.

The motor 1 includes a rotor 11 that rotates about a vertical axis line CL1, and a stator 12 disposed around the rotor 11. The motor 1 is, for example, an embedded magnet type synchronous motor, and a plurality of permanent magnets are embedded in a rotor 11 (rotor core) along a circumferential direction. Further, a synchronous reluctance motor, a switched reluctance motor, or the like having no magnet can be used as the motor 1.

The stator 12 has a substantially cylindrical stator core disposed with a gap of a predetermined length in the radial direction from the outer peripheral surface of the rotor 11 (rotor core) and centered on the axis CL 1. The stator core is a stator core, and has a plurality of slots formed in an inner circumferential surface thereof in a circumferential direction radially outward, and windings (coils) are arranged in the slots by concentrated windings or distributed windings. The rotor 11 rotates by causing a three-phase alternating current to flow through the windings to generate a rotating magnetic field.

The 1 st rotating shaft 13 is disposed inside the rotor 11 along the axis CL 1. The 1 st rotating shaft 13 is coupled to the rotor 11 by spline coupling, for example, and rotates integrally with the rotor 11. The upper end of the 1 st rotating shaft 13 protrudes from the upper end surface of the rotor 11, and the 1 st gear 14 having a diameter smaller than that of the rotor 11 is provided at the upper end. The 1 st gear 14 is coupled to the 1 st rotating shaft 13 by spline coupling, for example, and rotates integrally with the 1 st rotating shaft 13. The 1 st gear 14 is constituted by a spur gear or a helical gear, for example.

A pair of left and right 2-th rotation shafts 21 rotatable about an axis line CL2 in the vertical direction are provided on the sides (right rear side and left rear side) of the motor 1. The 2 nd gear 22 is provided at the upper end portions of the pair of 2 nd rotating shafts 21, respectively. Each 2 nd gear 22 is coupled to the 2 nd rotating shaft 21 by spline coupling, for example, and rotates integrally with the 2 nd rotating shaft 21. The left and right 2 nd gears 22 have the same structure, and are each composed of, for example, a spur gear or a helical gear. The 1 st gear 14 and the pair of 2 nd gears are located at the same height, and mesh with each other above the rotor 11 (on the inner circumferential surface side of the stator 12).

Worm shafts 23 constituting worm gears are provided below the 2 nd gear 22 and on the sides of the motor 1 on the left and right 2 nd rotating shafts 21. The left and right worms 23 have the same configuration and are screw-shaped gears in which continuous teeth are formed in a spiral shape. Each worm 23 is coupled to the 2 nd rotation shaft 21 by spline coupling, for example, and rotates integrally with the 2 nd rotation shaft 21. Further, the worm 23 may be provided on the outer peripheral surface of the 2 nd rotation shaft 21.

A pair of left and right worm wheels (helical gears) 31 rotatable about a left-right axis line CL3 are disposed coaxially with each other behind the left and right worms 23. The left and right worms 23 are engaged with the left and right worm wheels 31, respectively. The left and right worm wheels 31 have the same configuration and have a substantially cylindrical shape as a whole. The worm wheel 31 is located below the 2 nd gear 22. The axis CL3 is located at the center in the height direction of the motor 1, and the outer diameter of the worm wheel 31 is substantially equal to the height of the motor 1.

A pair of left and right 1 st planetary gear mechanisms 4 of a single pinion type having the same configuration are housed in the left and right worm gears 31, respectively. The left and right 1 st planetary gear mechanisms 4 each have: a sun gear 41, a ring gear 42 surrounding the sun gear 41, a plurality of (for example, 3) pinion gears 43 in the circumferential direction that mesh with the sun gear 41 and the ring gear 42, respectively, and a carrier 44 that rotatably supports the plurality of pinion gears 43. The sun gear 41, the ring gear 42, and the carrier 44 each rotate about an axis CL 3. The ring gear 42 is fixed to or formed on the inner peripheral surface of the worm wheel 31, and rotates integrally with the worm wheel 31.

The left and right carriers 44 extend to the left and right outside along the axis CL 3. That is, the carrier 44 of the left 1 st planetary gear mechanism 4 extends leftward, and the carrier 44 of the right 1 st planetary gear mechanism 4 extends rightward. A pair of left and right drive shafts 45 are coupled to the left and right ends of each carrier 44 by spline coupling or the like, and the carriers 44 rotate integrally with the drive shafts 45. Wheels (driving wheels), not shown, are coupled to an end of the drive shaft 45, and the drive shaft 45 rotates integrally with the wheels.

The pair of left and right rotary shafts 46 extending inward in the left and right directions along the axis CL3 are coupled to the left and right sun gears 41 by spline coupling or the like, and the left and right sun gears 41 rotate integrally with the left and right rotary shafts 46, respectively. The motor 5 is interposed between the left and right rotary shafts 46 in series with the double pinion type 2 nd planetary gear mechanism 6. The motor 1 may be referred to as a1 st motor, and the motor 5 may be referred to as a2 nd motor.

The motor 5 includes a rotor 51 that rotates about an axis CL3, and a stator 52 disposed around the rotor 51. The motor 5 is, for example, an embedded magnet type synchronous motor, and a plurality of permanent magnets are embedded in a rotor 51 (rotor core) along a circumferential direction. Further, a synchronous reluctance motor, a switched reluctance motor, or the like having no magnet can be used as the motor 5.

The stator 52 has a substantially cylindrical stator core centered on the axis CL3, which is disposed with a gap of a predetermined length in the radial direction from the outer peripheral surface of the rotor 51 (rotor core). The stator core is a stator core, and has a plurality of slots formed in an inner circumferential surface thereof in a circumferential direction radially outward, and windings (coils) are arranged in the slots by concentrated windings or distributed windings. The rotor 51 rotates by generating a rotating magnetic field by flowing a three-phase alternating current through the windings. A rotary shaft 51a of a rotor 51 of the motor 5 is coupled to a right end portion of the left rotary shaft 46 by spline coupling or the like, and the rotary shaft 46 and the rotor 51 rotate integrally.

The 2 nd planetary gear mechanism 6 has: the planetary gear set includes a sun gear 61, a ring gear 62 surrounding the sun gear 61, a plurality of 1 st and 2 nd pinion gears 63, 64 arranged between the sun gear 61 and the ring gear 62, respectively, meshing with the sun gear 61 and the ring gear 62, and supporting the plurality of 1 st and 2 nd pinion gears 63, 64 in a rotatable manner. The sun gear 61 and the carrier 65 rotate about the axis CL3, respectively. The ring gear 62 is fixed to a housing or the like and is not rotatable. The number of teeth of the ring gear 62 is 2 times that of the sun gear 61.

The carrier 65 extends rightward along the axis CL 3. The left end of the right rotary shaft 46 is coupled to the right end of the carrier 65 by spline coupling or the like, and the carrier 65 rotates integrally with the rotary shaft 46. The right end portion of the rotating shaft 51a of the rotor 51 is coupled to the sun gear 61 by spline coupling or the like, and the rotor 51 and the sun gear 61 rotate integrally.

The electric motor 5 is controlled by a command from a controller (ECU)8 via a Power Control Unit (PCU) 7. That is, the power control unit 7 includes an inverter, and controls the inverter in accordance with a command from the controller 8 to control the rotation (rotation speed and rotation direction) of the motor 5.

More specifically, the controller 8 includes an arithmetic processing unit having a CPU, a ROM, a RAM, and other peripheral circuits. Signals from a vehicle speed sensor 9a for detecting a vehicle speed and a steering angle sensor 9 for detecting a steering angle of a steering wheel are input to the controller 8, and the motor 5 is controlled based on these signals. In addition, the motor 1 is also controlled via the power control unit 7 by a command from the controller 8 in the same manner. The motor 1 is controlled in accordance with the operation amount of an accelerator pedal, for example. The motor 5, the 2 nd planetary gear mechanism 6, the controller 8, and the like constitute a speed difference absorbing device 101, and the speed difference absorbing device 101 absorbs a speed difference of the left and right drive shafts 45 when the vehicle turns.

Fig. 3 is a diagram showing a relationship between the target rotation speed difference Δ N of the left and right drive wheels and the target rotation speed Nm of the motor 5, which are stored in advance in the memory of the controller 8. The characteristic of fig. 3 is a characteristic of a ratio passing through 0. The target rotational speed difference Δ N is 0 when the vehicle travels straight, and becomes positive when the vehicle turns left, for example, and becomes negative when the vehicle turns right, for example. The larger the magnitude (absolute value) of the target rotation speed difference Δ N, the larger the target rotation speed Nm (absolute value).

The controller 8(CPU) calculates a target rotational speed difference Δ N based on signals from the vehicle speed sensor 9a and the steering angle sensor 9b, and calculates a target rotational speed Nm corresponding to the target rotational speed difference Δ N in accordance with the characteristics of fig. 3. Then, a control signal is output to the power control unit 7 so that the rotation speed of the motor 5 becomes the target rotation speed Nm.

The main operation of the vehicle driving device 100 configured as described above will be described. Fig. 4A and 4B are diagrams showing torque transmission paths during straight running and during cornering, respectively, and fig. 5A and 5B are diagrams showing examples of alignment charts of the vehicle driving device 100 during straight running and during cornering, respectively. In fig. 5A and 5B, the sun gear 41, the ring gear 42, and the carrier 44 of the 1 st planetary gear mechanism 4 on the left and right are denoted by 1S, 1R, and 1C, respectively, and the sun gear 61, the ring gear 62, and the carrier 65 of the 2 nd planetary gear mechanism 6 are denoted by 2S, 2R, and 2C, respectively. The rotational direction of the vehicle when advancing is defined as a positive direction, and + is used to represent the positive direction.

As shown by arrows a1 and a2 in fig. 4A, during the straight traveling, the torque of the motor 1 is transmitted to the pair of left and right worm wheels 31 via the 1 st rotation shaft 13, the 1 st gear 14, the pair of left and right 2 nd gears 22, the pair of left and right 2 nd rotation shafts 21, and the pair of left and right worms 23 that rotate integrally with the rotor 11. The structures from the 2 nd gear 22 to the worm wheel 31 are the same on the left and right, and therefore the left and right worm wheels 31 rotate at a constant speed with each other. The torque of the left and right worm gears 31 is transmitted to the left and right pair of drive shafts 45 via the left and right pair of first planetary gear mechanisms 4, whereby the vehicle travels.

In this case, the rotation of the motor 5 is stopped. Therefore, as shown in fig. 5A, the sun gears 41(1S) of the left and right 1 st planetary gear mechanisms 4 are all stopped, and the carriers 44(1C) of the left and right 1 st planetary gear mechanisms 4 rotate at the same speed N1. Whereby the vehicle travels straight.

As shown by arrows B1 and B2 in fig. 4B, the torque of the motor 1 is transmitted to the pair of left and right worm gears 31 during cornering travel, and then the torque of the left and right worm gears 31 is transmitted to the left and right drive shafts 45 via the 1 st planetary gear mechanism 4. At this time, as shown in fig. 5B, the motor 5 rotates at a target rotation speed Nm (for example, -N2) determined by the vehicle speed and the steering angle. Therefore, the rotation speed of the sun gear 61(2S) of the 2 nd planetary gear mechanism 6 is-N2, while the rotation speed of the carrier 65(2C) is + N2.

That is, as shown by arrows B3 and B4 in fig. 4B, the torque of the motor 5 is directly input to the sun gear 41 of the 1 st planetary gear mechanism 4 on the left side, whereas the torque of the motor 5, which is shifted through the 2 nd planetary gear mechanism 6, is input to the sun gear 41 of the 1 st planetary gear mechanism 4 on the right side, and therefore a difference occurs in the rotation speed of the left and right sun gears 41. Thus, as shown in fig. 5B, the rotation speed N3 of the carrier 44(1C) of the 1 st planetary gear mechanism 4 on the left side becomes slower than the rotation speed N4 of the carrier 44(1C) of the 1 st planetary gear mechanism 4 on the right side.

In this manner, in the present embodiment, the torque of the motor 1 is transmitted to the pair of left and right worm wheels 31 via the pair of left and right worms 23 during both the straight running and the cornering running. This makes it possible to easily transmit a large torque to the left and right drive shafts 45. That is, for example, when the torque of the motor 1 is transmitted to the single worm wheel via the single worm wheel, it is necessary to increase the diameter of the worm wheel when the transmission torque becomes large, and it is difficult to dispose the worm wheel 31 below the 2 nd gear 22. In contrast, as in the present embodiment, by distributing the torque of the motor 1 to the pair of left and right worm gears 31, the worm gears 31 can be easily disposed below the 2 nd gear 22 without enlarging the diameters of the worm gears 31. As a result, the vehicle drive device 100 can be prevented from being increased in size in the height direction.

The present embodiment can provide the following effects.

(1) The vehicle driving device 100 includes: a motor 1 having a rotor 11 that rotates about a vertical axis (1 st axis) CL1 and a stator 12 disposed around the rotor 11; a1 st rotating shaft 13 provided to extend along an axis CL1, having a1 st gear 14 at a distal end portion thereof, and rotatable integrally with the rotor 11; a pair of right and left 2 nd rotating shafts 21 which are vertically provided so as to be separated from each other in the right and left direction along a pair of right and left axes (2 nd axes) CL2 parallel to the axis CL1, respectively, and which have a2 nd gear 22 meshing with the 1 st gear 14 at a front end portion thereof, respectively, and are integrally provided with a worm 23 rotating around the axis CL 2; a pair of left and right worm wheels 31 which are provided so as to be engaged with the worms 23 of the pair of left and right 2 nd rotary shafts 21, respectively, and which are rotatable about a left-right axis (3 rd axis) CL 3; and a pair of left and right drive shafts 45 to which torque from the pair of left and right worm gears 31 is input (fig. 1 and 2), respectively.

With this mechanism, without increasing the size of the vehicle drive device 100 in the height direction, the torque of the electric motor 1 that rotates about the vertical axis CL1 can be transmitted to the worm wheel 31 that rotates about the horizontal axis CL3 while obtaining a sufficient reduction gear ratio, and the vehicle can be driven with a large torque. Therefore, the vehicle drive device 100 can be easily disposed in a predetermined space of the vehicle in which the height direction is limited. That is, the torque of the motor 1 is transmitted to the worm wheel 31 via the 2 nd gear 22 and the worm 23 provided at the distal end portion of the 2 nd rotating shaft 21 without via the bevel gear. Therefore, the diameter of the 2 nd gear 22 can be increased without increasing the height of the vehicle driving device 100, and a large torque can be easily transmitted to the drive shaft 45. Further, since the torque of the motor 1 is distributed to the pair of left and right worm wheels 31 via the pair of left and right worms 23, it is possible to easily transmit a large torque to the drive shaft 45 without increasing the diameter of the worm wheels 31.

(2) The vehicle driving device 100 further includes: a pair of left and right 1 st planetary gear mechanisms 4 which are respectively built in the pair of left and right worm gears 31 and transmit power from the pair of left and right worm gears 31 to the pair of left and right drive shafts 45; and a speed difference absorbing device 101 that absorbs a speed difference between the pair of left and right drive shafts 45 when the vehicle turns (fig. 2). This allows the rotation of the worm wheel 31 to be transmitted to the drive shaft 45 at a variable speed, and enables favorable turning travel.

(3) The pair of left and right 1 st planetary gear mechanisms 4 includes: a pair of left and right ring gears 42 connected to the pair of left and right worm gears 31, a pair of left and right carriers 44 connected to a pair of left and right drive shafts 45, and a pair of left and right sun gears 41 (fig. 2). The speed difference absorbing device 101 includes: a motor 5 and a double-pinion type 2 nd planetary gear mechanism 6 interposed in series between a pair of left and right sun gears 41, and a controller 8 for controlling the motor 5. This allows a rotation speed difference to be appropriately generated in the left and right drive shafts 45 in accordance with the driving of the motor 5. In addition, compared with the case of using a differential mechanism having a pair of left and right side gears, a pair of pinion gears, and the like, the use of the 2 nd planetary gear mechanism 6 of a double pinion type enables the entire apparatus to be downsized.

(4) The 2 nd planetary gear mechanism 6 has: a ring gear 62 provided so as not to be able to rotate, a carrier 65 connected to one of the pair of left and right sun gears 41, and a sun gear 61 connected to a rotating shaft 51a of the motor 5 (fig. 2). The number of teeth of the ring gear 62 of the 2 nd planetary gear mechanism 6 is 2 times the number of teeth of the sun gear 61 of the 2 nd planetary gear mechanism 6. This makes it possible to equalize the rotation speeds of the left and right rotary shafts (the sun gear 61 and the carrier 65) of the 2 nd planetary gear mechanism 6 and to reverse the rotation directions of the shafts. Therefore, a good turning characteristic can be obtained without causing a difference in the right and left turning characteristics.

In the above embodiment, the 1 st gear 14 is disposed above the motor 1, but the 1 st gear may be disposed below the motor. In this case, a pair of right and left 2 nd gears may be provided at the lower end portion of the 2 nd rotating shaft 21 so as to mesh with the 1 st gear. In the above embodiment, the pair of right and left 2 nd rotation shafts 21 are disposed diagonally behind the 1 st rotation shaft 13, but the 2 nd rotation shaft may be disposed diagonally in front of the 1 st rotation shaft. Therefore, the configuration of the worm wheel 31 is not limited to the above. In the above embodiment, the speed difference absorbing device 101 is configured by the electric motor 5, the 2 nd planetary gear mechanism 6, the controller (control unit) 8, and the like, but the configuration of the speed difference absorbing device is not limited to the above if it absorbs the speed difference between the pair of left and right drive shafts when the vehicle turns.

In the above embodiment, the 2 nd planetary gear mechanism 6 is disposed on the right side of the motor 5, but the 2 nd planetary gear mechanism may be disposed on the left side of the motor. The arrangement of the sun gear 61 and the carrier 65 of the 2 nd planetary gear mechanism 6 may be reversed left and right. In the above embodiment, the sun gear 41 of the 1 st planetary gear mechanism 4 is connected to the rotating shaft 51a of the motor 5, but a reduction gear may be attached to the motor 5 and connected to the 1 st planetary gear mechanism through the reduction gear. A clutch may be provided in the sun gear 61 or the carrier 65 of the 2 nd planetary gear mechanism 6, and the clutch may be engaged during cornering and disengaged during straight running. This can reduce heat generation of the motor 5 during the straight traveling.

One or more of the above embodiments and modifications may be arbitrarily combined, or modifications may be combined with each other.

The present invention makes it possible to easily dispose a vehicle drive device, which drives a vehicle by power of a motor, in a predetermined space of the vehicle, which is limited in the height direction.

While the preferred embodiments of the present invention have been described, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the scope of the disclosure of the following claims.