CN114909441A

CN114909441A - Motor speed reducer and vehicle drive device

Info

Publication number: CN114909441A
Application number: CN202111475401.9A
Authority: CN
Inventors: 戸贺﨑基; 石直克
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2021-02-10
Filing date: 2021-12-06
Publication date: 2022-08-16
Also published as: JP2022122325A

Abstract

The invention provides a motor reducer which has a relatively simple structure and can effectively inhibit NVH deterioration, and a vehicle driving device comprising the motor reducer. A motor speed reducer (2) is provided with a motor (M), a speed reduction mechanism (T), and a differential mechanism (D). The speed reduction mechanism (T) includes two planetary gear mechanisms, a first planetary gear mechanism (PG1) and a second planetary gear mechanism (PG 2). A carrier (C1) of the first planetary gear mechanism (PG1) and a carrier (C2) of the second planetary gear mechanism (PG2) are rotatably connected to each other by a connection section (30). The connecting part (30) comprises a radial bearing (32) and an annular elastic body (34) fixed on an outer ring (32C) of the radial bearing (32), a gear carrier (C1) is fixed on an inner ring (32a), and the gear carrier (C2) is fixed on the elastic body (34).

Description

Motor speed reducer and vehicle drive device

Technical Field

The present invention relates to a motor speed reducer for reducing an output of a motor, and a vehicle drive device including the motor speed reducer.

Background

In recent years, electric vehicles (hereinafter referred to as "ev (electric vehicle)") using an electric motor (motor) as a drive source have been developed. The EV is provided with a drive transmission device including a speed reducer that decelerates an output of the motor and transmits the output to an axle. In the EV, it is important to reduce the size and weight of the vehicle from the viewpoint of improving the traveling performance and energy efficiency of the vehicle. Therefore, the drive transmission device including the speed reducer as described above is configured to obtain a high reduction ratio, but is also required to be as small and light as possible. In order to increase the degree of freedom in the design of the vehicle, it is desirable to make the reduction gear and the drive transmission device as compact as possible.

In order to meet such a demand, patent document 1 proposes a motor speed reducer including: the electric motor having a hollow cylindrical output shaft, a speed reduction mechanism to which a driving force from the output shaft of the electric motor is input, and a differential mechanism to distribute and transmit the driving force reduced by the speed reduction mechanism to the left and right axles are coaxially arranged, and the speed reduction mechanism includes a planetary gear mechanism, and one of the axles transmitting an output from the differential mechanism is provided so as to penetrate the inside of the output shaft. The planetary gear mechanism has the following structure: a first planetary gear mechanism that inputs a driving force from an output shaft and a second planetary gear mechanism that outputs the driving force input from the first planetary gear mechanism to a differential mechanism are arranged in series in the direction of the output shaft.

As for the bearing structure, the following structure is described: both ends of the output shaft are rotatably supported by a housing of the electric motor by bearings (bearing), and the gear case of the differential mechanism and the axle penetrating the inside of the output shaft are rotatably supported by a housing of the electric motor by bearings.

In the above configuration, the electric motor, the speed reduction mechanism, and the differential mechanism are arranged coaxially with each other, and the axle for transmitting the output of the differential mechanism penetrates the inside of the output shaft of the electric motor, whereby the reduction gear can be made compact in outer diameter size, and can be made compact and lightweight. In particular, since the height dimension or lateral width dimension of the speed reducer can be suppressed to be small by disposing the electric motor, the speed reduction mechanism, and the differential mechanism coaxially, it is possible to easily adopt a design unique to the EV vehicle, such as lowering of a hood wire (bonnet line) of the vehicle, or shortening of a front overhang (front overhang). In addition to this, since the speed reduction mechanism uses a planetary gear mechanism, a high speed reduction ratio can be obtained.

[ Prior art documents ]

[ patent document ]

[ patent document 1] Japanese patent laid-open publication No. 2011-102639

Disclosure of Invention

[ problems to be solved by the invention ]

Fig. 5 is a schematic view (skeieton map) showing a state during driving, that is, during torque transmission in the conventional motor reducer. In the motor speed reducer 100 shown in fig. 5, symbol B9 denotes a bearing that is fixed to the casing 10 and supports a carrier (carrier) C2 of the second planetary gear mechanism PG 2. In this state, a tooth surface reaction force of the gear between the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2 is generated, and therefore, the alignment of the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2 is maintained by the tooth surface reaction force, and there is also an automatic centering function in the first planetary gear mechanism PG1 and the second planetary gear mechanism PG 2. That is, such a planetary gear mechanism has a self aligning function (automatic centering function) and automatically moves to a rotationally stable position by engaging gears when torque transmission from a motor is started.

Fig. 6 is a schematic view showing a state in which the conventional motor reducer is not driven, that is, torque transmission is not performed. For example, when the driver releases the accelerator pedal (by stopping the output of the motor) from the state shown in fig. 5 and changes to a state in which torque transmission is not performed (coasting) state), the tooth surface reaction force of the gear between the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2 disappears. When the tooth surface reaction force of the gear disappears, as shown in fig. 6, the carrier C1 of the first planetary gear mechanism PG1 is supported only by the bearing B4, and therefore, a backlash (backlash) amount state is achieved. In particular, when the state of torque transmission suddenly changes to a state of no torque transmission, the alignment between the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2 changes or is in an inappropriate state, and there is a possibility that Noise, Vibration, and Harshness (NVH) (Noise, Vibration and Harshness): mechanical Vibration and Noise) temporarily deteriorates. Fig. 6 exaggeratedly shows the tilting of the carrier C1.

As described above, in the conventional technology, in a configuration in which two planetary gear mechanisms (planetary gear sets) are arranged coaxially in series, when a tooth surface reaction force of a gear suddenly disappears, for example, when an accelerator pedal is suddenly released from an acceleration state and a coasting state (a state in which inertia running is performed without transmitting torque from a motor to a drive wheel side) is changed, there is a possibility that the alignment of the planetary gear mechanisms is changed or an inappropriate state is caused, and sufficient suppression of NVH, which is an index of vehicle comfort, cannot be achieved.

The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a motor reducer having a relatively simple configuration and capable of effectively suppressing deterioration of NVH, and a vehicle drive device including the motor reducer.

[ means for solving the problems ]

In order to solve the above problem, a motor speed reducer according to the present invention is a motor speed reducer including a speed reduction mechanism T to which a driving force from a motor M is input, the speed reduction mechanism T including at least two planetary gear mechanisms including a first planetary gear mechanism PG1 and a second planetary gear mechanism PG2, and a

connection portion

30 or 40 that connects one rotating element C1 of the first planetary gear mechanism PG1 and one rotating element C2 of the second planetary gear mechanism PG2 so as to be relatively rotatable, the

connection portion

30 or 40 including: an intermediate bearing 32 or 42 including a radial bearing that supports the rotary element C1 of the first planetary gear mechanism PG1 and the rotary element C2 of the second planetary gear mechanism PG2 so as to be relatively rotatable; and an

elastic body

34 or 44 provided between at least either one of intermediate bearing 32 or 42 and rotational element C1 of first planetary gear mechanism PG1, or intermediate bearing 32, 42 and rotational element C2 of second planetary gear mechanism PG 2.

According to the motor speed reducer of the present invention, since the intermediate bearing including the radial bearing that supports the one rotating element of the first planetary gear mechanism and the one rotating element of the second planetary gear mechanism so as to be relatively rotatable is provided, when the speed reducer mechanism does not transmit torque from the motor, the gear reaction force disappears and the rotating element to be tilted is supported by the intermediate bearing, and therefore tilting of the rotating element (tilting of the rotating shaft) can be suppressed to the minimum. Therefore, it is possible to effectively prevent the alignment of the planetary gear mechanism from being changed or in an inappropriate state, so that sufficient suppression of NVH can be achieved. Further, by including the elastic body provided between the intermediate bearing and the rotating element of the first planetary gear mechanism or between the intermediate bearing and the rotating element of the second planetary gear mechanism, when the speed reducing mechanism transmits torque from the motor, the elastic action of the elastic body achieves proper alignment of the rotating elements without hindering the self-aligning action exerted by the reaction force of the gear tooth surface. Therefore, it is possible to effectively prevent the alignment of the planetary gear mechanism from being changed or in an inappropriate state even when torque transmission is performed, and thus it is possible to achieve sufficient suppression of NVH. Thus, the following motor reducer is obtained: the alignment of the planetary gear mechanism can be always maintained in an appropriate state both when there is torque transmission from the motor to the speed reduction mechanism and when there is no torque transmission from the motor to the speed reduction mechanism, so that sufficient suppression of NVH can be achieved.

In the motor speed reducer, it is preferable that: the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2 are coaxially arranged in series, the rotating element C1 of the first planetary gear mechanism PG1 is the carrier C1 of the first planetary gear mechanism PG1, and the rotating element C2 of the second planetary gear mechanism PG2 is the carrier C2 of the second planetary gear mechanism PG 2. Accordingly, the elasticity (elastic force) generated by the elastic body acts between the carrier of the first planetary gear mechanism and the carrier of the second planetary gear mechanism, which are main elements supporting the gear mesh, and therefore, the alignment of the planetary gear mechanisms can be maintained in a more appropriate state, and NVH can be suppressed with higher accuracy.

In the motor speed reducer, it is preferable that: the

elastic body

34 or 44 is fixed to the outer ring 32C or the inner ring 42a of the intermediate bearing 32 or 42, and either one of the carrier C1 of the first planetary gear mechanism PG1 and the carrier C2 of the second planetary gear mechanism PG2 is fixed to the

elastic body

34 or 44. According to the above configuration, the intermediate bearing uses a universal radial bearing, and a coupling portion capable of effectively suppressing NVH with a relatively simple and inexpensive configuration can be realized.

In addition, the motor reducer preferably has the following configuration: the

elastic body

34 or 44 is formed in a ring shape. According to the structure, the manufacturing of the elastic body becomes easy, and the assembly (fixing) to the intermediate bearing also becomes easy.

In the motor reducer, it is preferable that the carrier C1 of the first planetary gear mechanism PG1 and the carrier C2 of the second planetary gear mechanism PG2 be directly or indirectly rotatably supported by bearings B4 and B5 fixed to the housing 10 of the motor reducer at positions distant from the

connection portions

30 and 40 in the axial direction of the output shaft L1 of the motor M. Accordingly, the rotational stability of the carriers C1 and C2 is further improved, and the NVH suppression accuracy is further improved.

Further, a vehicle drive device according to the present invention includes: a motor M; the speed reducer for a motor of any of the above configurations of the present invention includes a speed reduction mechanism T to which a driving force from a motor M is input; and a differential mechanism D for distributing and transmitting the driving force decelerated by the deceleration mechanism T to the left and right axles.

[ Effect of the invention ]

According to the motor reducer and the vehicle drive device including the same of the present invention, deterioration of NVH can be effectively suppressed, though the structure is relatively simple.

Drawings

Fig. 1 is a schematic view showing the configuration of a vehicle drive device including a motor reducer according to a first embodiment of the present invention.

Fig. 2A and 2B are views showing a connection portion of the motor reducer shown in fig. 1, fig. 2A being a front view, and fig. 2B being a schematic cross-sectional view taken along line X1-X1 of fig. 2A.

Fig. 3 is a schematic diagram showing the configuration of a vehicle drive device including a motor reducer according to a second embodiment of the present invention.

Fig. 4A and 4B are views showing a connection portion of the motor reducer shown in fig. 3, fig. 4A being a front view, and fig. 4B being a schematic cross-sectional view taken along line X2-X2 of fig. 4A.

Fig. 5 is a view for explaining a problem of the conventional structure, and is a contour view showing a state when a motor reducer (driving device) is driven.

Fig. 6 is a view for explaining a problem of the conventional structure, and is an outline view showing a state when a motor reducer (driving device) is not driven.

Description of the symbols of the drawings:

1. 1-2: a vehicle drive device;

2. 2-2: a speed reducer (motor speed reducer);

10: a housing;

20: a gear case;

30. 40: a connecting portion;

32. 42: radial bearings (intermediate bearings);

32a, 42 a: an inner ring;

32c, 42 c: an outer ring;

34. 44: an elastomer;

b4, B5: bearings (other bearings);

c1, C2: a gear carrier (rotating element);

d: a differential mechanism (differential mechanism);

l1: a rotor shaft (output shaft);

l2, L3: an axle;

m: a motor (electric motor);

PG 1: a first planetary gear mechanism;

PG 2: a second planetary gear mechanism;

s1, S2: a sun gear;

p1, P2: a pinion gear;

r1, R2: an inner gear ring;

t: a speed reduction mechanism.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[ first embodiment ]

Fig. 1 is a schematic view showing a configuration of a vehicle drive device including a motor speed reducer (hereinafter, simply referred to as a "speed reducer") according to a first embodiment of the present invention. The vehicle drive device 1 includes: a motor M as an electric motor having a rotor shaft L1 as a hollow cylindrical output shaft; a motor speed reducer 2 having a speed reduction mechanism T including a planetary gear mechanism to which a driving force from a rotor shaft L1 of a motor M is input; and a differential mechanism D as a differential mechanism for distributing and transmitting the driving force decelerated by the deceleration mechanism T of the motor reducer 2 to the left and right axles L2, L3. The motor M, the reduction mechanism T, and the differential mechanism D are coaxially arranged, and one of the axles L2, which transmits the output from the differential mechanism D, is provided to penetrate through the inside of the rotor shaft L1. The front end of the axle L2 is connected to wheels (drive wheels), not shown. The reduction mechanism T includes two planetary gear mechanisms (planetary gear sets) of a first planetary gear mechanism PG1 on the motor M side and a second planetary gear mechanism PG2 on the differential mechanism D side.

First planetary gear mechanism PG1 includes sun gear (sun gear) S1, carrier C1, pinion gear (pinion gear) P1, ring gear (ring gear) R1, and second planetary gear mechanism PG2 includes sun gear S2, carrier C2, pinion gear P2, ring gear R2. The sun gear S1 of the first planetary gear mechanism PG1 is coupled to the rotor shaft L1 of the motor M, and the carrier C1 is coupled to the sun gear S2 of the second planetary gear mechanism PG 2. The pinion gear P1 is rotatably held on the carrier C1 by a bearing B1. The carrier C2 of the second planetary gear mechanism PG2 is integrally formed with the gear case 20 of the differential mechanism D. The pinion gear P2 is rotatably held on the carrier C2 by a bearing B2. Further, ring gear R1 of first planetary gear mechanism PG1 and ring gear R2 of second planetary gear mechanism PG2 are fixed to case 10 of vehicle drive device 1. A bearing B3 in the thrust direction is disposed between the first planetary gear mechanism PG1 and the second planetary gear mechanism PG 2.

Carrier C1 as one rotating element of first planetary gear mechanism PG1 and carrier C2 as one rotating element of second planetary gear mechanism PG2 are relatively rotatably coupled by coupling unit 30. The carrier C1 is directly supported by the bearing B4 fixed to the casing 10 at a position distant from the coupling portion 30 in the axial direction (right side in the drawing) of the rotor shaft L1, and the carrier C2 is indirectly supported by the bearing B5 fixed to the casing 10 at a position distant from the coupling portion 30 in the axial direction (left side in the drawing) of the rotor shaft L1 via the gear box 20. In fig. 1, reference symbols B6 and B7 denote bearings that support the rotor shaft L1, and reference symbol B8 denotes a bearing that supports one end of the axle L2.

In the vehicle drive device 1, the output from the rotor shaft L1 of the motor M is input to the sun gear S1 in a state where the ring gear R1 of the first planetary gear mechanism PG1 is fixed to the case 10. Then, the driving force decelerated by the first planetary gear mechanism PG1 is output from the carrier C1, and the output from the carrier C1 is input to the sun gear S2 of the second planetary gear mechanism PG 2. Then, since the ring gear R2 of the second planetary gear mechanism PG2 is fixed with respect to the case 10, the driving force decelerated by the second planetary gear mechanism PG2 is output from the carrier C2 to the differential mechanism D.

In the vehicle drive device 1 of the present embodiment, as described above, the motor M, the reduction mechanism T, and the differential mechanism D are coaxially arranged, and one of the axles L2 that transmits the output of the differential mechanism D penetrates the inside of the rotor shaft L1, whereby the vehicle drive device 1 can be made compact in outer diameter size, and can be made compact and lightweight. In particular, by arranging the motor M, the speed reduction mechanism T, and the differential mechanism D coaxially, the height dimension of the vehicle drive device 1 and the lateral width dimension in the direction orthogonal to the axial direction of the rotor shaft L1 can be suppressed to be small, and therefore, it is possible to easily adopt a design unique to the EV vehicle, such as lowering the engine hood of the vehicle or shortening the front overhang.

Next, the NVH deterioration suppressing function in the vehicle drive device 1 will be described. As shown in fig. 2A and 2B, the coupling portion 30 includes a radial bearing (intermediate bearing) 32, and the carrier C1 and the carrier C2 are supported by the radial bearing (intermediate bearing) 32 so as to be relatively rotatable. The radial bearing 32 has an inner race 32a, a rolling body (roller) 32b, and an outer race 32 c. An annular elastic body 34 is fixed to the outer peripheral surface of the outer ring 32c, and the annular elastic body 34 has elasticity in a state of being laminated in a direction orthogonal to the axial direction of the rotor shaft L1. In the present embodiment, the carrier C1 of the first planetary gear mechanism PG1 is fixed to the inner ring 32a, and the carrier C2 of the second planetary gear mechanism PG2 is fixed to the elastic body 34. That is, the elastic body 34 is provided between the carriers C1 and C2, which are the rotary elements of the connecting portion 30. Thus, the following structure is formed: between the carrier C1 of the first planetary gear mechanism PG1 and the carrier C2 of the second planetary gear mechanism PG2, an elastic force generated by the elastic body 34 acts in a direction intersecting the axial direction of the rotor shaft L1.

As described above, in the present embodiment, since the carrier C1 and the carrier C2 are provided so as to be relatively rotatable with the elastic body 34 interposed therebetween, the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2 are appropriately aligned without hindering the automatic alignment function that is exerted by the tooth surface reaction force of the gear. Therefore, even if the gear tooth surface reaction force disappears when the first planetary gear mechanism PG1 and the second planetary gear mechanism PG2 are in a state in which torque is not transmitted, the carrier C1 is inclined, and the carrier C1 is maintained in a state in which alignment is not changed by the elasticity of the elastic body 34. In addition, even if torque transmission is performed, the automatic centering function is not hindered by the elasticity of the elastic body 34. That is, the displacement when the gears are engaged and move to the rotationally stable position is absorbed by the elasticity of the elastic body 34.

As shown in fig. 1, in the present embodiment, during driving (during torque transmission from the motor M to the reduction gear T), the carrier C1 of the first planetary gear mechanism PG1 is supported by the bearing B4 and the tooth surface formed by the meshing of the sun gear S1 and the pinion P1, and the carrier C2 of the second planetary gear mechanism PG2 is supported by the bearing B5 and the tooth surface formed by the meshing of the sun gear S2 and the pinion P2. Further, during non-driving (when torque is not transmitted from the motor M to the reduction gear T), the carrier C1 of the first planetary gear mechanism PG1 is supported by the bearing B4 and the connection section 30, and the carrier C2 of the second planetary gear mechanism PG2 is supported by the bearing B5 and the connection section 30. This can effectively suppress NVH both when the device is driven and when the device is not driven.

Further, if the elastic modulus of the elastic body 34 is excessively small, sufficient elasticity cannot be exhibited, and there is a possibility that the carrier C1 falls down as shown in fig. 6 of the conventional structure, and thus sufficient suppression of NVH cannot be achieved. Conversely, if the elastic modulus is excessively large, the rigidity may hinder the self-aligning function, and in this case, sufficient suppression of NVH may not be achieved. Therefore, the material of the elastic body 34 can be appropriately selected within a range having appropriate rigidity and attenuation characteristics that do not hinder the self-aligning function.

Further, if the carrier C1 and the carrier C2 are connected by only the radial bearing 32 without providing the elastic body 34, the carrier C1 and the carrier C2 can be prevented from falling down by the support of the radial bearing 32, but the automatic centering function by the tooth surface reaction force of the gear is hindered by the constraint of the radial bearing 32 as a rigid body, and therefore there is a possibility that sufficient suppression of NVH cannot be achieved.

[ second embodiment ]

Next, a second embodiment of the present invention will be described with reference to fig. 3 and 4A and 4B. The same portions as or portions regarded as the same as those of the embodiment are denoted by the same symbols, and the already-described portions are appropriately omitted.

Fig. 3 is a schematic diagram showing the configuration of a vehicle drive device including a motor reducer according to a second embodiment of the present invention. Fig. 4A and 4B are views showing a connection portion of the motor reducer shown in fig. 3, fig. 4A being a front view, and fig. 4B being a schematic cross-sectional view taken along line X2-X2 of fig. 4A. As shown in fig. 3, in the motor reducer 2-2 of the vehicle driving device 1-2 according to the present embodiment, a carrier C1 as one rotating element of the first planetary gear mechanism PG1 and a carrier C2 as one rotating element of the second planetary gear mechanism PG2 are rotatably coupled to each other by a coupling portion 40. As shown in fig. 4A and 4B, the coupling 40 includes a radial bearing 42, and the carrier C1 and the carrier C2 are supported by the radial bearing 42 so as to be relatively rotatable. The radial bearing 42 has an inner race 42a, a rolling body (roller) 42b, and an outer race 42 c. An annular elastic body 44 is fixed to an inner peripheral surface of the inner ring 42a, and the annular elastic body 44 has elasticity in a state of being laminated in a direction orthogonal to the axial direction of the rotor shaft L1. That is, in the present embodiment, the elastic body 44 is interposed between the carrier C2 and the radial bearing 42, the carrier C1 of the first planetary gear mechanism PG1 is fixed to the elastic body 44, and the carrier C2 of the second planetary gear mechanism PG2 is fixed to the outer ring 42C of the radial bearing 42. Therefore, in the present embodiment, as in the first embodiment, the following structure is also formed: between the carrier C1 of the first planetary gear mechanism PG1 and the carrier C2 of the second planetary gear mechanism PG2, an elastic force generated by the elastic body 44 acts in a direction intersecting the axial direction of the rotor shaft L1. Therefore, the NVH suppression function similar to that of the first embodiment can be obtained also in the present embodiment.

While the embodiments of the present invention have been described above, the present invention is not limited to the embodiments, and various modifications can be made within the scope of the technical ideas described in the claims, the specification, and the drawings. For example, the material of the

elastic bodies

34 and 44 is not limited to rubber, and a metal material such as a plate spring may be used. The shapes of the

elastic bodies

34 and 44 are not limited to the annular shape, and may be discontinuous in the circumferential direction.

Claims

1. A motor speed reducer comprising a speed reduction mechanism to which a driving force from a motor is input,

the reduction gear mechanism includes at least two planetary gear mechanisms including a first planetary gear mechanism and a second planetary gear mechanism, and has a coupling portion that couples one rotating element of the first planetary gear mechanism and one rotating element of the second planetary gear mechanism so as to be relatively rotatable,

the joint portion includes: an intermediate bearing including a radial bearing that supports a rotating element of the first planetary gear mechanism and a rotating element of the second planetary gear mechanism so as to be relatively rotatable; and an elastic body provided at least either between the intermediate bearing and the rotating element of the first planetary gear mechanism or between the intermediate bearing and the rotating element of the second planetary gear mechanism.

2. A speed reducer for a motor according to claim 1, wherein:

the first planetary gear mechanism and the second planetary gear mechanism are coaxially arranged in series,

the rotating element of the first planetary gear mechanism is a carrier of the first planetary gear mechanism,

the rotating element of the second planetary gear mechanism is a carrier of the second planetary gear mechanism.

3. A speed reducer for a motor according to claim 2, wherein:

the elastic body is fixed to an outer ring or an inner ring of the intermediate bearing, and either one of the carrier of the first planetary gear mechanism and the carrier of the second planetary gear mechanism is fixed to the elastic body.

4. A motor reducer according to claim 3, wherein: the elastic body is formed in a ring shape.

5. A speed reducer for a motor according to any one of claims 1 to 4, wherein:

the carrier of the first planetary gear mechanism and the carrier of the second planetary gear mechanism are directly or indirectly rotatably supported by another bearing fixed to a housing of the motor reducer at a position distant from the connection portion in the axial direction of the output shaft of the motor.

6. A vehicular drive apparatus comprising:

an electric motor;

the speed reducer for a motor according to any one of claims 1 to 5, comprising a speed reduction mechanism that inputs a driving force from the motor; and

and a differential mechanism for distributing and transmitting the driving force decelerated by the deceleration mechanism to the left and right axles.