JP7028671B2 - Vehicle drive - Google Patents

Description

The present invention relates to, for example, a vehicle driving device in which a rotational driving force of an electric motor is input to a speed reducer to reduce the rotational speed and transmit it to a wheel bearing.

As a kind of conventional vehicle drive device, for example, there is an in-wheel motor drive device (electric drive unit) disclosed in Patent Document 1.

The in-wheel motor drive device of Patent Document 1 includes an electric motor that generates a driving force for the wheels and a speed reducer that decelerates and outputs the rotation of the electric motor, and drives the wheels to rotate by the rotational output of the electric motor. It is configured to do.

This in-wheel motor drive device has a structure in which an electric motor and a speed reducer are integrally housed in a casing.

The electric motor includes a stator fixed to the casing, a rotor rotatably supported by the casing inside the stator, and a rotor shaft that outputs the rotation of the rotor.

The reducer is composed of a parallel shaft gear train and a planetary gear mechanism. The parallel shaft gear train transmits the rotation of the rotor shaft of the electric motor to the planetary gear mechanism by decelerating in the first stage with respect to the output shaft. The planetary gear mechanism transmits the rotation of the rotor shaft of the electric motor to the output shaft by decelerating in the second stage.

Japanese Unexamined Patent Publication No. 2015-147491

By the way, the in-wheel motor drive device disclosed in Patent Document 1 includes a speed reducer that decelerates by a parallel shaft gear train and a planetary gear mechanism, and by bringing the parallel shaft gear train and the planetary gear mechanism closer to each other in the axial direction. , We are trying to reduce the size of the entire unit in the axial direction.

On the other hand, in this type of in-wheel motor drive device, lubricating oil for cooling the electric motor and cooling and lubricating the speed reducer is sealed in the casing. This lubricating oil cools the electric motor, and the reduction gear is cooled and lubricated by the bouncing of the rotation of each gear of the parallel shaft gear train and the planetary gear mechanism.

As described above, in the in-wheel motor drive device, by reducing the size of the entire unit in the axial direction, the internal parts that make up the in-wheel motor drive device, especially the gears that make up the reducer, are narrowed inside the reducer case. It will be incorporated and placed in a space.

Therefore, in the case of a bearing in which the gear is rotatably supported with respect to the speed reducer case and is arranged close to the gear, the lubricating oil is repelled by the rotating gear, and it becomes difficult for the lubricating oil to reach the bearing. Insufficient lubrication may reduce the durability of the bearing.

In addition, since the amount of lubricating oil adhering to the inner wall surface of the speed reducer case close to the bearing is small, it is difficult to sufficiently lubricate the bearing with a small amount of lubricating oil, and this insufficient lubrication reduces the durability of the bearing. It may decrease.

Therefore, the present invention has been proposed in view of the above-mentioned problems, and an object thereof is a vehicle drive capable of reliably supplying lubricating oil to bearings of gears arranged in a narrow space by a simple structure. To provide the equipment.

The vehicle drive device according to the present invention includes a structure including an electric motor for driving wheels, a speed reducer for decelerating and outputting the rotation of the electric motor, and a casing for accommodating the speed reducer.

In this vehicle drive device, a bearing that rotatably supports the gear of the reduction gear is attached to the wall surface of the casing, and the outer diameter of the tooth tip of the gear is larger than the outer diameter of the outer ring of the bearing. It has a structure in which bearings are arranged in a narrow space between them.

As a technical means for achieving the above-mentioned object, in the present invention, the tooth tip of the gear is close to the top surface of the casing, and the lubricating oil scattered by the rotation of the gear is applied to the upper portion of the bearing on the top surface of the casing. It is characterized by forming a recess to be retained.

In the present invention, by providing the recess in the upper portion of the bearing on the top surface where the tooth tips of the gears are close to each other, the lubricating oil scattered by the rotating gear stays in the recess. As a result, the amount of lubricating oil flowing down from the top surface of the casing to the bearing along the wall surface increases.

As a result, even if the gear bearing mounted on the wall surface of the casing is arranged close to the end face of the gear in the narrow space between the wall surface of the casing and the end face of the gear, the amount of lubricating oil flowing down to the bearing By increasing the number of gears, sufficient lubricating oil can be reliably supplied to the bearings of the gears.

It is desirable that the recess in the present invention is formed so as to extend in the axial direction of the gear and is inclined downward toward the wall surface of the casing.

If such a structure is adopted, the lubricating oil accumulated in the concave portion on the top surface of the casing can easily flow down toward the wall surface of the casing. Therefore, sufficient lubricating oil can be more reliably supplied to the gear bearings.

It is desirable that the recess in the present invention has a width dimension that overlaps with at least a part of the outer diameter of the outer ring of the bearing.

If such a structure is adopted, at least a part of the bearing will be located directly under the recess. As a result, the lubricating oil flowing down from the recess on the top surface of the casing along the wall surface can be more reliably supplied to the gear bearings.

In the present invention, it is desirable that the wall surface of the casing is provided with ribs extending from both sides of the recess toward the bearing side.

If such a structure is adopted, the lubricating oil flowing down from the concave portion on the top surface of the casing along the wall surface can be guided to the bearing of the gear along the rib. With this rib, the lubricating oil flowing down from the concave portion on the top surface of the casing along the wall surface can be more reliably supplied by the bearing of the gear.

In the present invention, it is desirable to have a structure in which an oil groove for allowing lubricating oil to flow into the bearing is formed in a portion below the recess of the bearing support portion provided on the wall surface of the casing.

If such a structure is adopted, the lubricating oil flowing down from the concave portion on the top surface of the casing along the wall surface flows into the oil groove of the bearing support portion. With this oil groove, the lubricating oil flowing down from the concave portion on the top surface of the casing along the wall surface can be more reliably supplied by the bearing of the gear.

According to the present invention, even if the gear bearing provided on the wall surface of the casing is arranged close to the end face of the gear in a narrow space between the wall surface of the casing and the end face of the gear, the bearing is placed on the wall surface of the casing. By increasing the amount of lubricating oil flowing down, sufficient lubricating oil can be reliably supplied to the bearings of the gears.

As a result, the durability of the bearing can be improved, and a highly reliable and long-life vehicle drive device can be provided.

It is sectional drawing which shows the whole structure of the in-wheel motor drive device in embodiment of this invention. FIG. 3 is a cross-sectional view of the parallel shaft gear reducer (input gear, intermediate gear, and output gear) of FIG. 1 as viewed from the wheel side. FIG. 3 is an enlarged cross-sectional view of a main part showing a casing, an intermediate gear, and a bearing thereof in an embodiment of the present invention. FIG. 3 is an enlarged cross-sectional view of a main part showing a casing, an intermediate gear, and a bearing thereof in another embodiment of the present invention. It is a partial cross-sectional view which shows an example of the positional relationship between the bearing of an intermediate gear, and the recess of a casing. It is a partial cross-sectional view which shows the other example of the positional relationship between the bearing of an intermediate gear, and the recess of a casing. It is a partial cross-sectional view which shows the other example of the positional relationship between the bearing of an intermediate gear, and the recess of a casing. It is a partial cross-sectional view which shows the structural example which provided the rib on the wall surface of a casing. It is a partial cross-sectional view which shows the structural example which provided the oil groove in the bearing support part of an intermediate gear. It is a top view which shows the schematic structure of the electric vehicle equipped with the in-wheel motor drive device. It is a rear sectional view which shows the electric vehicle of FIG.

As an embodiment of the present invention, the in-wheel motor drive device will be described in detail with reference to the drawings. 10 is a schematic plan view of an electric vehicle 11 equipped with an in-wheel motor drive device 21, and FIG. 11 is a schematic cross-sectional view of the electric vehicle 11 as viewed from the rear.

As shown in FIG. 10, the electric vehicle 11 includes a chassis 12, a front wheel 13 as a steering wheel, a rear wheel 14 as a drive wheel, and an in-wheel motor drive device 21 for transmitting a driving force to the rear wheel 14. Equip.

As shown in FIG. 11, the rear wheel 14 is housed inside the wheel housing 15 of the chassis 12 and is fixed to the lower part of the chassis 12 via an independent suspension type suspension device (suspension) 16.

The electric vehicle 11 is provided with an in-wheel motor drive device 21 that independently drives the left and right rear wheels 14 inside the wheel housing 15. This eliminates the need to provide a motor, drive shaft and differential gear mechanism on the chassis 12.

As a result, the electric vehicle 11 has an advantage that a large cabin space can be secured and the rotation of the left and right rear wheels 14 can be independently controlled.

On the other hand, in the electric vehicle 11, it is necessary to suppress the unsprung weight in order to improve the running stability and NVH characteristics. Further, in order to secure a large cabin space, the in-wheel motor drive device 21 is required to be downsized.

Therefore, the in-wheel motor drive device 21 of the embodiment shown in FIG. 1 has the following structure. As a result, a compact in-wheel motor drive device 21 is realized, and by suppressing the unsprung weight, an electric vehicle 11 having excellent running stability and NVH characteristics is obtained.

Before explaining the characteristic configuration of this embodiment, the overall configuration of the in-wheel motor drive device 21 will be described. In the following description, with the in-wheel motor drive device 21 mounted on the vehicle body, the side closer to the outside of the vehicle body is referred to as the outboard side (left side in the drawing), and the side closer to the center is referred to as the inboard side (right side in the drawing). It is called.

As shown in FIG. 1, the in-wheel motor drive device 21 includes an electric motor 22 that drives the rear wheels 14 (see FIGS. 10 and 11) and a parallel shaft gear reducer that reduces and outputs the rotation of the electric motor 22. 23 and a wheel bearing 24 that transmits the output of the parallel shaft gear reducer 23 to the rear wheel 14 described above.

In this embodiment, the radial gap type electric motor 22 is exemplified, but other electric motors such as the axial gap type may be used.

The electric motor 22 and the parallel shaft gear reducer 23 are housed in the casing 25. The casing 25 in which the electric motor 22 and the parallel shaft gear reducer 23 are housed is mounted in the wheel housing 15 (see FIG. 11) of the electric vehicle 11.

The electric motor 22 is integrally rotated with the stator 26 fixed to the casing 25, the rotor 27 arranged so as to face each other with a gap inside the stator 26 in the radial direction, and the rotor 27 arranged radially inside the rotor 27. The motor rotating shaft 28 is provided.

The motor rotation shaft 28 can rotate at high speed at about 10,000 to several thousand rotations per minute. The stator 26 is configured by winding a coil around the outer circumference of the magnetic core. A permanent magnet or a magnetic material is arranged inside the rotor 27.

The motor rotating shaft 28 holds the rotor 27 by a holder portion 29 extending radially outward. The motor rotating shaft 28 is rotatably supported with respect to the casing 25 by bearings 30 and 31.

The parallel shaft gear reducer 23 includes an input gear 32, an intermediate gear 33, and an output gear 34. The intermediate gear 33 coaxially has a large diameter tooth portion 35 on the inboard side and a small diameter tooth portion 36 on the outboard side.

In the parallel shaft gear reducer 23, the tooth portion 37 of the input gear 32 and the large diameter tooth portion 35 of the intermediate gear 33 mesh with each other, and the small diameter tooth portion 36 of the intermediate gear 33 and the tooth portion 38 of the output gear 34 mesh with each other. As a result, the rotation of the electric motor 22 is reduced by a predetermined reduction ratio.

Since the in-wheel motor drive device 21 is housed inside the wheel housing 15 (see FIG. 11) and has an unsprung load, it is essential to reduce the size and weight.

Therefore, by using the parallel shaft gear reducer 23 having a large reduction ratio, the electric motor 22 can be miniaturized by combining with the high-speed rotating electric motor 22, and the compact and high reduction ratio in-wheel motor drive device 21 can be obtained. It can be realized.

The input gear 32 is coaxially attached to the motor rotating shaft 28 by spline fitting. The input gear 32, the intermediate gear 33, and the output gear 34 are rotatably supported by the casing 25 by bearings 39 to 44. The output gear 34 is coaxially attached to the hub wheel 46 of the wheel bearing 24 by spline fitting.

FIG. 2 is a cross-sectional view of the input gear 32, the intermediate gear 33, and the output gear 34 of the parallel shaft gear reducer 23 as viewed from the outboard side. The rotation centers C1 to C3 of the input gear 32, the intermediate gear 33, and the output gear 34 are offset from each other in the positional relationship shown in FIG.

By arranging the input gear 32, the intermediate gear 33, and the output gear 34 in an offset manner in this way, the parallel shaft gear reducer 27 is made compact in the axial direction and the radial direction.

Here, helical gears are used for the input gear 32, the intermediate gear 33, and the output gear 34. Helical gears are effective in that the number of teeth that mesh with each other increases at the same time and the tooth contact is dispersed, so that the sound is quiet and the torque fluctuation is small.

In this way, by using helical gears for the parallel shaft gear reducer 23, it is possible to realize an in-wheel motor drive device 21 that is easy to manufacture, can reduce costs, and is quiet and efficient in terms of performance. can.

The wheel bearing 24 includes an outer ring 45 fixed to the casing 25, an inner ring 47 press-fitted into the hub ring 46 and the hub ring 46 arranged inside the outer ring 45, and the hub ring 46, the inner ring 47, and the outer ring 45. The main part is composed of a plurality of rolling elements 48 arranged between them.

Preload is applied to the wheel bearing 24 by crimping the inboard side end of the hub wheel 46. By applying this preload, the wheel bearing 24 has a double-row angular contact ball bearing structure.

A shaft portion 50 integrally extending from the output gear 34 of the parallel shaft gear reducer 23 to the outboard side is coupled to the shaft hole 49 of the hub wheel 46 of the wheel bearing 24 so that torque can be transmitted by spline fitting. ..

Seal members 51 are provided at both ends of the wheel bearing 24 in the axial direction in order to prevent the intrusion of muddy water and the like and prevent the leakage of grease.

A flange 52 is integrally formed on the outboard side of the hub ring 46. A rear wheel 14 (see FIGS. 10 and 11) is connected to the flange 52 by a hub bolt (not shown).

In the in-wheel motor drive device 21 having the above configuration, the rotation of the electric motor 22 is decelerated by the input gear 32, the intermediate gear 33 and the output gear 34 of the parallel shaft gear reducer 23, and is transmitted to the wheel bearing 24.

Since the rotation of the electric motor 22 is decelerated by the parallel shaft gear reducer 23 and transmitted to the wheel bearing 24, the rear wheels 14 (FIGS. 10 and 10) even when a low torque and high-speed rotation type electric motor 22 is adopted. It is possible to transmit the torque required for (see 11).

The overall configuration of the in-wheel motor drive device 21 in this embodiment is as described above, but the characteristic configuration thereof will be described in detail below.

In the in-wheel motor drive device 21, lubricating oil for cooling the electric motor 22 and cooling and lubricating the parallel shaft gear reducer 23 is sealed in the internal space of the casing 25.

In particular, as shown in FIG. 2, the parallel shaft gear reducer 23 is placed in an oil bath state in which a part of the tooth portion 38 of the output gear 34 is constantly immersed in the lubricating oil 53, and the parallel shaft gear reducer 23 is splashed by the rotation of the output gear 34. It cools and lubricates.

By immersing only the output gear 34 having the slowest rotation speed in this way, there is an effect of avoiding a decrease in efficiency of the parallel shaft gear reducer 23 due to an increase in the stirring resistance of the lubricating oil 53.

Here, in order to realize a lightweight and compact in-wheel motor drive device 21, the input gear 32, the intermediate gear 33, and the output gear 34 of the parallel shaft gear reducer 23 are densely arranged and the output gear 34 is densely arranged as shown in FIG. The radial gap and the axial gap between the parallel shaft gear reducer 23 and the casing 25 are made as small as possible.

On the other hand, a pump (not shown) is arranged above the input gear 32, and lubricating oil is dropped from the pump to cool and lubricate the input gear 32 and its bearings 39 and 40. On the other hand, with respect to the intermediate gear 33, it is difficult in terms of space to arrange the pump as in the input gear 32 described above.

Further, for the intermediate gear 33 having a large diameter tooth portion 35 having a tooth tip outer diameter larger than the bearing outer ring outer diameter, the bearing 41 on the inboard side is housed and arranged in the recess 54 of the large diameter tooth portion 35. As a result, the parallel shaft gear reducer 23 is miniaturized in the axial direction.

As a result, since the bearing 41 on the inboard side is arranged in the narrow space 57 between the wall surface 55 of the casing 25 and the concave end surface 56 of the large diameter tooth portion 35 of the intermediate gear 33, the output gear 34 has a bearing 41. It is difficult for the lubricating oil 53 splashed by the rotation and the lubricating oil 53 adhering to the wall surface 55 of the casing 25 to reach.

In this parallel shaft gear reducer 23, the bearing 41 of the intermediate gear 33 in which the outer diameter of the tip of the large diameter tooth portion 35 is larger than the outer diameter of the outer ring of the bearing 41 is formed on the wall surface 55 of the casing 25 and the concave end surface 56 of the intermediate gear 33. It is arranged in a narrow space 57 between and.

Therefore, as shown in FIG. 2, the parallel shaft gear reducer 23 of this embodiment is intermediate between the upper portion of the bearing outer ring of the top surface 58 of the casing 25 in which the tooth tips of the large diameter tooth portions 35 of the intermediate gear 33 are close to each other. It has a structure in which a recess 59 is formed to retain the lubricating oil 53 scattered by the rotation of the gear 33.

In this parallel shaft gear reducer 23, the recess 59 is provided in the upper portion of the bearing on the top surface 58 of the casing 25 in which the tooth tips of the large diameter tooth portions 35 of the intermediate gear 33 are close to each other. Lubricating oil 53 scattered by force stays in the recess 59. As a result, the amount of lubricating oil flowing down from the top surface 58 of the casing 25 along the wall surface 55 increases.

As a result, the bearing 41 of the intermediate gear 33 provided on the wall surface 55 of the casing 25 becomes the concave end surface 56 of the intermediate gear 33 in the narrow space 57 between the wall surface 55 of the casing 25 and the concave end surface 56 of the intermediate gear 33. Even if they are arranged in close proximity to each other, sufficient lubricating oil 53 can be reliably supplied to the bearing 41 of the intermediate gear 33 due to the increase in the amount of lubricating oil flowing down along the wall surface 55.

As a result, the durability of the bearing 41 of the intermediate gear 33 can be improved, and a highly reliable and long-life in-wheel motor drive device 21 can be provided.

As shown in FIG. 3, the recess 59 of the top surface 58 of the casing 25 is formed so as to extend in the axial direction of the intermediate gear 33, and is inclined downward toward the wall surface 55 of the casing 25.

By adopting such a structure, the lubricating oil 53 staying in the recess 59 of the top surface 58 of the casing 25 easily flows down along the wall surface 55 of the casing 25. Therefore, sufficient lubricating oil 53 can be reliably supplied to the bearing 41 of the intermediate gear 33.

In this embodiment, the top surface 58 and the recess 59 that are inclined downward toward the wall surface 55 of the casing 25 are illustrated, but as shown in FIG. 4, the sky extending horizontally toward the wall surface 55 of the casing 25. It may be a surface 58 and a recess 60.

Even with the structure as shown in FIG. 4, at the normal traveling speed of the vehicle, the amount of lubricating oil that is repelled by the centrifugal force due to the rotation of the intermediate gear 33 is sufficient, so that the lubricating oil 53 sufficiently stays in the recess 59. do. As a result, the lubricating oil 53 flows down from the top surface 58 of the casing 25 along the wall surface 55, and the lubricating oil 53 can be reliably supplied to the bearing 41.

5, 6 and 7 illustrate the positional relationship between the bearing 41 of the intermediate gear 33 and the recess 59 of the top surface 58 of the casing 25. The intermediate gear 33 is not shown.

FIG. 5 illustrates a recess 59 formed in a portion above the outer ring of the bearing 41 with a width dimension W1 that matches the outer diameter of the outer ring of the bearing 41. As shown in FIGS. 6 and 7, the recess 59 may be formed with width dimensions W2 and W3 so as to overlap a part of the outer ring outer diameter of the bearing 41.

On the top surface 58 of the casing 25, the recess 59 shown in FIG. 6 is arranged rearward in the rotation direction of the bearing 41, and the recess 59 shown in FIG. 7 is arranged in front of the bearing 41 in the rotation direction. Further, the recesses 59 in FIGS. 6 and 7 have width dimensions W2 and W3 that are approximately half the outer diameter of the outer ring of the bearing 41.

In this way, by forming the recess 59 with the width dimensions W1, W2, W3 so as to overlap at least a part of the outer ring outer diameter of the bearing 41, at least a part of the bearing 41 is positioned directly under the recess 59. Become. As a result, the lubricating oil 53 flowing down from the recess 59 of the top surface 58 of the casing 25 along the wall surface 55 can be reliably supplied to the bearing 41 of the intermediate gear 33.

Further, as shown in FIG. 8, a structure in which ribs 60 extending from both sides of the recess 59 to the support portion 61 of the bearing 41 are provided on the wall surface 55 of the casing 25 is effective. The illustrated ribs 60 are provided above the bearing 41 on both sides of the recess 59, but the number thereof is arbitrary.

As a result, the lubricating oil 53 flowing down from the recess 59 of the top surface 58 of the casing 25 along the wall surface 55 can be guided to the bearing 41 along the rib 60. The rib 60 can reliably supply the lubricating oil 53 flowing down from the recess 59 of the casing 25 along the wall surface 55 to the bearing 41 of the intermediate gear 33.

When the lubricating oil 53 flowing down from the recess 59 along the wall surface 55 is guided to the bearing 41, the ribs 60 located inside on both sides of the recess 59 work particularly effectively, but the ribs located on both sides of the recess 59 are located on the outside. 60 also contributes to guiding the overflowing lubricating oil 53 to the bearing 41.

Further, as shown in FIG. 9, an oil groove 62 for allowing the lubricating oil 53 to flow into the bearing 41 may be provided in a portion below the recess of the support portion 61 of the bearing 41.

As a result, the lubricating oil 53 that has flowed down from the recess 59 of the top surface 58 of the casing 25 along the wall surface 55 flows into the oil groove 62 of the support portion 61. The oil groove 62 can reliably supply the lubricating oil 53 that has flowed down from the recess 59 of the casing 25 along the wall surface 55 to the bearing 41 of the intermediate gear 33.

In the above embodiment, the vehicle drive device in which the in-wheel motor drive device 21 for driving the left and right rear wheels 14 is provided inside the wheel housing 15 (see FIG. 11) has been described, but the present invention is limited thereto. It can also be applied to a vehicle drive device called an onboard type.

In this on-board type vehicle drive device, two sets of electric motors 22 and a parallel shaft gear reducer 23 are attached to the vehicle body, and the output of the parallel shaft gear reducer 23 is transmitted to the rear wheels 14 via the left and right drive shafts. It has a structure to be used.

Alternatively, a set of an electric motor 22 and a parallel shaft gear reducer 23 is attached, and the output of the parallel shaft gear reducer 23 is distributed to the left and right by a differential gear and transmitted to the rear wheels 14 via a drive shaft.

Further, in the above embodiment, as shown in FIGS. 10 and 11, the electric vehicle 11 having the rear wheels 14 as the driving wheels is exemplified, but the front wheels 13 may be the driving wheels, and the vehicle is a four-wheel drive vehicle. May be good. In addition, in this specification, "electric vehicle" is a concept including all automobiles that obtain driving force from electric power, and includes, for example, a hybrid car and the like.

The present invention is not limited to the above-described embodiments, and it is needless to say that the present invention can be carried out in various forms without departing from the gist of the present invention. Indicated by the scope of the claim and further include the equal meanings set forth in the claims, and all modifications within the scope.

21 In-wheel motor drive device 22 Electric motor 23 Reducer (parallel shaft gear reducer)
24 Wheel bearings 25 Casing 33 Gears (intermediate gears)
41 Bearing 55 Wall surface 56 End face 57 Space 58 Top surface 59 Recess 60 Rib 61 Bearing support 62 Oil groove

Claims (5)

A vehicle drive device including an electric motor for driving wheels, a speed reducer for decelerating and outputting the rotation of the electric motor, and a casing for accommodating the speed reducer.
A bearing that rotatably supports the gear of the speed reducer is attached to the wall surface of the casing, and the outer diameter of the tooth tip of the gear is larger than the outer diameter of the outer ring of the bearing. The bearings are arranged in the narrow space between them.
A vehicle drive characterized in that the tooth tips of the gears are close to the top surface of the casing and a recess is formed in a portion above the bearing on the top surface of the casing to retain the lubricating oil scattered by the rotation of the gears. Device. The vehicle drive device according to claim 1, wherein the recess is formed so as to extend in the axial direction of the gear and is inclined downward toward the wall surface of the casing. The vehicle drive device according to claim 1 or 2, wherein the recess is formed with a width dimension so as to overlap at least a part of the outer ring outer diameter of the bearing. The vehicle drive device according to any one of claims 1 to 3, wherein ribs extending from both sides of the recess toward the bearing side are provided on the wall surface of the casing. The vehicle drive device according to any one of claims 1 to 4, wherein an oil groove for allowing lubricating oil to flow into the bearing is formed in a portion below a recess of a bearing support portion provided on a wall surface of the casing.

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