WO2017154252A1

WO2017154252A1 - In-wheel motor drive device

Info

Publication number: WO2017154252A1
Application number: PCT/JP2016/079335
Authority: WO
Inventors: 佐藤　勝則
Original assignee: Ntn株式会社
Priority date: 2016-03-10
Filing date: 2016-10-03
Publication date: 2017-09-14
Also published as: JP6843511B2; JP2017159817A

Abstract

An in-wheel motor drive device (21) has: a motor section (A); a speed reducer section (B) constituted by a parallel shaft gear speed reducer (39) comprising a plurality of gears; a bearing section (C) for a wheel; and a rotary pump (60) for delivering lubricating oil under pressure. An intermediate shaft (S2) having intermediate gears (33, 34) is disposed between the input shaft (30a) of the speed reducer section (B) and an output shaft (36), and the intermediate shaft (S2) drives the rotary pump (60). The rotary pump (60) is disposed on the outer diameter side of the motor section (A) so as to radially overlap the motor section (A).

Description

In-wheel motor drive device

The present invention relates to an in-wheel motor drive device in which, for example, an output shaft of an electric motor and a wheel bearing are connected via a speed reducer.

Since the in-wheel motor drive device is mounted inside the wheel, an increase in the weight of the drive device leads to an increase in the unsprung load of the vehicle. Since an increase in unsprung load deteriorates running stability and NVH characteristics, it is important to reduce the size and weight of the driving device. Also, from the viewpoint of avoiding interference with the vehicle body and suspension parts when mounted on the vehicle, the drive device must be downsized.

∙ Since the output torque of the motor is proportional to the motor size and weight, a large motor is required to generate the torque necessary for driving the vehicle with the motor alone. If a large motor is used, not only will the weight increase, but the in-wheel motor drive device may interfere with the vehicle body and suspension parts when the wheel rotates in the steering direction or vibrates up and down. For this reason, in the conventional in-wheel motor drive device, the rotation of the motor with high rotation and low torque is transmitted to the wheel via the speed reduction mechanism, so that the motor is often downsized.

The in-wheel motor drive device is provided with a lubrication mechanism that supplies lubricating oil pumped by an oil pump to the motor and reducer via an oil path in order to lubricate and cool components such as motors, bearings, and gears. It is done. If the oil pump of the lubrication mechanism is driven by the output of the wheel driving motor, it is not necessary to separately install a motor dedicated to the pump, which is advantageous for cost reduction and space saving.

As an example of the lubrication mechanism described above, for example, Japanese Patent No. 4501911 (Patent Document 1) discloses an in-wheel motor drive device that drives an oil pump with a gear shaft of a counter gear that constitutes a speed reduction mechanism. .

Japanese Patent No. 4501911

However, in the in-wheel motor drive device of Patent Document 1, the oil pump is arranged inside the counter gear. Therefore, if the oil pump is replaced with a large-sized product having a large axial dimension for the purpose of increasing the capacity of the pump, the oil pump may protrude from the counter gear in the axial direction. In an in-wheel motor drive device, it is desired to reduce its axial dimension as much as possible in relation to the arrangement space of the suspension device. In response to this, various components are densely arranged in the axial direction inside the drive device. Placed in. For this reason, if the oil pump protrudes from the counter gear in the axial direction, the axial dimension of the motor portion, and hence the axial dimension of the entire in-wheel motor drive device, increases, which is contrary to the above requirement.

Also, in order to secure an accommodation space for the oil pump, the counter gear web needs to be thinned or offset in the axial direction with respect to the tooth surface of the counter gear, which may reduce the strength of the counter gear.

Thus, the problem with the conventional in-wheel motor driving device is that the size change of the oil pump (increase in axial dimension) directly affects the axial dimension of the entire in-wheel motor driving device.

Therefore, an object of the present invention is to provide an in-wheel motor drive device that can avoid an increase in axial dimension even when the size of the oil pump is changed.

As technical means for achieving the above-mentioned object, the present invention includes a motor unit for driving a wheel, a speed reducer unit composed of a parallel shaft gear reducer composed of a plurality of gears, a wheel bearing unit, In an in-wheel motor drive device having a rotary pump that pumps lubricating oil, an intermediate shaft having an intermediate gear is disposed between an input shaft and an output shaft of a reduction gear unit, and the rotary pump is driven by the intermediate shaft. The rotary pump is arranged on the outer diameter side of the motor unit so as to overlap the motor unit in the radial direction.

In the in-wheel motor drive device of the present invention, since the rotary pump is driven by the intermediate shaft, the rotary pump can be driven at a low rotational speed, and the quietness and durability of the rotary pump can be enhanced. Especially when the rotary pump overlaps with the motor part in the radial direction and is arranged on the outer diameter side of the motor part, the axial dimension of the motor part increases and the in-wheel motor drive device even when the rotary pump is enlarged It is possible to prevent an increase in the axial dimension. The in-wheel motor drive device limits the increase in the axial dimension in consideration of the installation space of the suspension device, but the present invention makes it unnecessary to change the design of the suspension device, and the existing suspension device is utilized as it is. be able to. In this case, it is preferable that the tooth surface of the intermediate gear and the rotary pump are arranged apart from each other in the axial direction.

If the parallel shaft gear reducer is provided with a plurality of intermediate shafts, and the rotary pump is driven by an intermediate shaft other than the intermediate shaft on the most upstream side in the torque transmission direction among the plurality of intermediate shafts, the rotary pump is driven. It becomes easy to separate the intermediate shaft in the radial direction of the motor unit. Therefore, it becomes easy to arrange the rotary pump on the outer diameter side of the motor unit.

If the intermediate gear provided on the intermediate shaft for driving the rotary pump is configured with an idler gear, the reduction ratio between the input shaft and the output shaft can be prevented from becoming excessively large. For this reason, it is possible to increase the degree of freedom in selecting the reduction ratio between the input shaft and the output shaft.

According to the present invention, it is possible to avoid an increase in the axial dimension of the motor unit and further the in-wheel motor drive device even when the size of the rotary pump is changed.

It is a front view which shows schematic structure when the in-wheel motor drive device arrange | positioned in the inner space of the wheel is seen from the inboard side. FIG. 2 is a cross-sectional view taken along the line PP connecting the centers Oa, O1, O2, and Ob in FIG. FIG. 2 is a cross-sectional view taken along the line QQ connecting the centers Oa and O2 in FIG. It is a front view which shows schematic structure when the in-wheel motor drive device arrange | positioned in the inner space of the wheel is seen from the inboard side. FIG. 5 is a cross-sectional view taken along the line RR connecting the centers Oa, O1, O2, and Ob in FIG. FIG. 5 is a cross-sectional view taken along the line SS connecting the centers Oa and O2 in FIG. It is a top view which shows schematic structure of the electric vehicle carrying an in-wheel motor drive device. FIG. 8 is a rear sectional view showing the electric vehicle of FIG. 7.

Embodiments of an in-wheel motor drive device according to the present invention will be described in detail with reference to the drawings.

FIG. 7 is a schematic plan view of the electric vehicle 11 on which the in-wheel motor drive device 21 is mounted, and FIG. 8 is a schematic cross-sectional view of the electric vehicle 11 as viewed from the rear.

As shown in FIG. 7, the electric vehicle 11 includes a chassis 12, a front wheel 13 as a steering wheel, a rear wheel 14 as a driving wheel, and an in-wheel motor driving device 21 that transmits driving force to the rear wheel 14. Equip. As shown in FIG. 8, the rear wheel 14 is accommodated in a tire house 15 of the chassis 12 and fixed to the lower portion of the chassis 12 via a suspension device (suspension) 16.

The suspension device 16 supports the rear wheel 14 by a suspension arm that extends to the left and right, and suppresses vibration of the chassis 12 by absorbing vibration received by the rear wheel 14 from the ground by a strut including a coil spring and a shock absorber. A stabilizer that suppresses the inclination of the vehicle body during turning or the like is provided at a connecting portion of the left and right suspension arms. The suspension device 16 is an independent suspension type in which the left and right wheels are independently moved up and down in order to improve the followability to the road surface unevenness and efficiently transmit the driving force of the rear wheel 14 to the road surface.

The electric vehicle 11 is provided with the in-wheel motor drive device 21 that drives the left and right rear wheels 14 inside the tire house 15, thereby eliminating the need for a motor, a drive shaft, a differential gear mechanism, and the like on the chassis 12. Therefore, there is an advantage that a wide cabin space can be secured and the rotation of the left and right rear wheels 14 can be controlled.

Before describing the characteristic configuration of this embodiment, the overall configuration of the in-wheel motor drive device 21 will be described with reference to FIGS. 1 and 2. In the following description, in a state where the in-wheel motor drive device 21 is mounted on the vehicle, the side closer to the outside of the vehicle is referred to as the outboard side, and the side closer to the center is referred to as the inboard side.

FIG. 1 is a front view showing a schematic configuration when the in-wheel motor drive device 21 disposed in the inner space of the wheel W of the rear wheel 14 is viewed from the inboard side. FIG. 2 is a cross-sectional view taken along line PP connecting the motor center Oa, the two intermediate shaft centers O1 and O2, and the axle center Ob in FIG.

As shown in FIGS. 1 and 2, the in-wheel motor drive device 21 includes a motor part A that generates a driving force, a speed reducer part B that decelerates and outputs the rotation of the motor part A, and a speed reducer part B. Is provided with a wheel bearing portion C that transmits the output to the rear wheel 14 as a drive wheel. The motor part A, the speed reducer part B, and the wheel bearing part C are each accommodated in the casing 22. As shown in FIG. 2, the casing 22 may have a monolithic structure or a separable structure.

As shown in FIG. 2, the motor part A is arranged on the stator 23 fixed to the casing 22, the rotor 24 arranged so as to face the inner side in the radial direction of the stator 23 with a gap, and the inner side in the radial direction of the rotor 24. Thus, a radial gap type electric motor 26 having a motor rotating shaft 25 that rotates integrally with the rotor 24 is formed. The motor rotating shaft 25 can rotate at a high speed of about 10,000 to 1000 rotations per minute. The stator 23 is configured by winding a coil around the outer periphery of the magnetic core, and the rotor 24 is configured by a permanent magnet or the like.

The motor rotating shaft 25 is connected to the casing 22 by the rolling bearing 40 at one end in the axial direction (left side in FIG. 2) and by the rolling bearing 41 at the other end in the axial direction (right side in FIG. 2). Each is supported rotatably.

The reduction gear unit B includes an input gear 30, a first intermediate gear 31, a second intermediate gear 32, a third intermediate gear 33, a fourth intermediate gear 34, and an output gear 35 as a plurality of intermediate gears. The input gear 30 integrally has an input shaft 30a, and the input shaft 30a is connected to the motor rotating shaft 25 coaxially by spline fitting (including serration fitting, the same applies hereinafter). The first intermediate gear 31 is formed integrally with the first intermediate shaft S1, and the second intermediate gear 32 is connected to the first intermediate shaft S1 by spline fitting. The fourth intermediate gear 34 is formed integrally with the second intermediate shaft S2, and the third intermediate gear 33 is connected to the second intermediate shaft S2 by spline fitting. The output gear 35 is formed integrally with a hollow output shaft 36.

The input shaft 30a, the first intermediate shaft S1, the second intermediate shaft S2, and the output shaft 36 are arranged in parallel to each other. The input shaft 30a is provided with rolling

bearings

42 and 43, the first intermediate shaft S1 is provided with rolling

bearings

44 and 45, the second intermediate shaft S2 is provided with rolling

bearings

46 and 47, and the output shaft 36 is provided with rolling

bearings

48 and 49, respectively. 22 is supported rotatably.

In this reduction gear section B, the input gear 30 and the first intermediate gear 31 are engaged, the second intermediate gear 32 and the third intermediate gear 33 are engaged, and the fourth intermediate gear 34 and the output gear 35 are engaged. ing. The number of teeth of the first intermediate gear 31 is larger than the number of teeth of the input gear 30 and the second intermediate gear 32 on both sides of the torque transmission direction, and the number of teeth of the third intermediate gear 33 is the second intermediate gear on both sides of the torque transmission direction. 32 and the number of teeth of the fourth intermediate gear 34. Further, the number of teeth of the output gear 35 is larger than the number of teeth of the fourth intermediate gear 34. From the above configuration, the parallel shaft gear reducer 39 is configured to decelerate the rotational motion of the motor rotating shaft 25 in three stages.

In this embodiment, helical gears are used as the input gear 30, the intermediate gears 30 to 34, and the output gear 35 that constitute the parallel shaft gear reducer 39. Helical gears are effective in that the number of teeth engaged simultaneously increases and the tooth contact is dispersed, so that the sound is quiet and torque fluctuation is small. It is preferable to set the modules of each gear to about 1 to 3 in consideration of the meshing ratio of gears and the limit number of rotations.

The wheel bearing portion C is composed of a wheel bearing 57 having the following configuration. The wheel bearing 57 is an outer ring rotating type, and includes an axle 51 fixed to a knuckle (not shown), two inner rings 52 fitted and fixed to the outer peripheral surface of the axle 51, and a hub wheel disposed on the outer peripheral side of the inner ring 52. 53, a plurality of balls 54 disposed between an inner race formed on the outer peripheral surface of the inner ring 52 and an outer race formed on the inner peripheral surface of the hub ring 53, and a cage 55 that holds each ball 54. Double row angular contact ball bearings.

The nut 56 is screwed into and tightened with the male thread portion formed at the shaft end of the axle 51, thereby preventing separation of the wheel bearing 57 and applying a preload inside the bearing. The wheel W (see FIG. 1) is fixed to a flange 53a provided on the hub wheel 53 via a hub bolt (not shown). The hub wheel 53 is disposed on the inner periphery of the hollow output shaft 36 of the parallel shaft gear reducer 39 and is connected to the output shaft 36 by spline fitting. Thereby, the output of the reduction gear part B is transmitted to the rear wheel 14. In the present embodiment, the outer ring rotation type is used as the wheel bearing 57, but the inner ring rotation type can also be used as the wheel bearing 57 by changing the position of the output gear 35.

As shown in FIGS. 1 and 2, the center Oa (motor center) of the motor 26 is at a position eccentric in the radial direction of the motor 26 with respect to the center Ob (axle center) of the axle 51. The center O1 (first intermediate shaft center) of the first intermediate shaft S1 and the center O2 (second intermediate shaft center) of the second intermediate shaft S2 are on one side with respect to a line connecting the motor center Oa and the axle center Ob. In the area. The second intermediate shaft center O2 is located between the motor center Oa and the axle center Ob. FIG. 1 illustrates a case where the in-wheel motor driving device 21 is disposed in the wheel W in such a posture that a line connecting the motor center Oa and the axle center Ob is substantially horizontal.

Since the in-wheel motor drive device 21 is housed in the tire house 15 (see FIG. 8) and becomes an unsprung load, a reduction in size and weight is essential. By combining the parallel shaft gear reducer 39 with the electric motor 26, it is possible to use a small electric motor 26 of low torque and high rotation type. For example, when the parallel shaft gear reducer 39 having a reduction ratio of 11 is used, the electric motor 26 can be reduced in size by using the electric motor 26 that rotates at a high speed of about ten thousand rotations per minute. Thereby, the compact in-wheel motor drive device 21 can be realized, and the electric vehicle 11 excellent in running stability and NVH characteristics can be obtained while suppressing the unsprung weight.

Next, the lubrication mechanism in the in-wheel motor drive device 21 will be described with reference to FIGS. Here, FIG. 3 is a sectional view taken along the line QQ connecting the motor center Oa and the second intermediate shaft center O2 in FIG.

The lubrication mechanism cools the motor part A and the speed reducer part B and circulates and supplies lubricating oil to them for further lubrication. As shown in FIG. 1, the lubrication mechanism of this embodiment mainly includes a rotary pump 60 and

oil passages

65, 66, and 67 disposed in the casing 22.

1 and 3, the discharge port 63 and the suction port 64 of the rotary pump 60 are provided in the casing 22. An oil passage 65 extending from the discharge port 63 of the rotary pump 60 extends to the motor portion A and is connected to a circulating oil passage 67 that circulates in the vicinity of the outer diameter end portion of the motor 26 inside the motor portion A. The circulation oil passage 67 is provided with distribution ports 68 facing the stator 23 of the motor 26 at a plurality of locations in the circumferential direction. An oil passage (not shown) for supplying lubricating oil to various parts of the parallel shaft gear reducer 39 is connected to the discharge port 63 of the rotary pump 60 as necessary.

The suction port 64 of the rotary pump 60 is connected to one end of a reflux oil passage 66 for returning the lubricating oil to the rotary pump 60. The other end of the reflux oil passage 66 extends downward and opens into a space in the casing 22 near the bottom wall of the casing 22. As shown in FIG. 1, the lubricating oil is stored in the lower part of the casing 22, and the oil level X is in a position where the lower region of the output gear 35 is immersed in the lubricating oil. Regardless of whether the in-wheel motor drive device 21 is driven or stopped, the other end of the reflux oil passage 66 is in the lubricating oil stored in the lower portion of the casing 22.

As shown in FIGS. 1 and 2, the rotary pump 60 is a cycloid pump including an inner rotor 61 having a plurality of external teeth and an outer rotor 62 having a plurality of internal teeth. The rotary pump 60 is incorporated in the casing 22 by a presser plate 69.

The second intermediate shaft S2 is attached to the inner rotor 61 via a detent such as a D-cut or a two-sided width. Accordingly, the inner rotor 61 is rotationally driven by the rotation of the second intermediate shaft S2. Further, the outer rotor 62 is rotatably supported with respect to the casing 22 so as to be driven and rotated as the inner rotor 61 rotates. Since the inner rotor 61 and the outer rotor 62 are in an eccentric state, the volume of the pump chamber formed between the inner rotor 61 and the outer rotor 62 is continuously changed while the inner rotor 61 and the outer rotor 62 are rotating. As a result, the lubricating oil sucked from the suction port 64 is pumped from the discharge port 63 to the oil passage 65. When the number of teeth of the inner rotor 61 is n, the number of teeth of the outer rotor 62 is (n + 1). In this embodiment, n = 7.

By driving the rotary pump 60, the lubricating oil sucked up from the oil reservoir at the bottom of the casing 22 through the circulating oil passage 66 is pumped from the discharge port 63 of the rotary pump 60 and distributed via the

oil passages

65 and 67. It is discharged from the mouth 68. Thereby, the motor 26 is cooled. Further, the lubricating oil in the oil sump at the bottom of the casing 22 is splashed by the rotation of the output gear 35 at various locations in the parallel shaft gear reducer 39, and cooling and lubrication are performed at various locations. At the same time, lubricating oil is supplied from the discharge port 63 to various portions of the parallel shaft gear reducer 39 through an oil passage (not shown), and the reducer B is cooled and lubricated. The motor rotation shaft 25, the first intermediate shaft S1, and the second intermediate shaft S2 are provided with an axial oil passage and a radial oil passage extending from the axial oil passage to the meshing portion of the tooth surfaces. By forming, it is also possible to employ a so-called shaft center oil supply structure in which the lubricating oil is supplied to the meshing portion between the tooth surfaces by the centrifugal force and the pumping force of the rotary pump 60.

The lubricating oil that has cooled and lubricated the motor part A and the speed reducer part B travels along the inner wall surface of the casing 22 by gravity and accumulates at the bottom of the casing 22. The lubricating oil is sucked up from the oil passage 66 and returned to the suction port 64 of the rotary pump 60, whereby the lubricating oil can be circulated and supplied to the motor part A and the speed reducer part B.

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

In this embodiment, the rotary pump 60 is coupled to the second intermediate shaft S2 of the speed reducer part B, and the rotary pump 60 is driven by the rotation of the second intermediate shaft S2. Therefore, the rotary pump 60 can be driven at a low rotational speed, and the silence and durability of the rotary pump 60 can be improved.

Further, in this embodiment, the rotary pump 60 coupled to the second intermediate shaft S2 is arranged on the outer diameter side of the motor part A in a state of overlapping with the motor part A in the radial direction. Specifically, the inner rotor 61 and the out rotor 62 of the rotary pump 60 are arranged adjacent to the outer diameter side of a partial region in the axial direction of the motor 26 (for example, the stator 23). Therefore, even if the axial dimension of the rotary pump 60 is increased, the axial dimension of the motor part A does not increase. Therefore, the capacity of the rotary pump 60 can be increased without increasing the axial dimension of the in-wheel motor drive device 21. The rotary pump 60 does not overlap the tooth surfaces of the third intermediate gear 33 and the tooth surfaces of the fourth intermediate gear 34 provided on the second intermediate shaft S2 in the radial direction. It is in a position separated in the direction. In this respect, the configuration is different from that of the in-wheel motor driving device described in Patent Document 1.

Thus, the axial dimension of the in-wheel motor drive device 21 is maintained, so that it is not necessary to change the design of the suspension device including the suspension arm and the like. Therefore, when the in-wheel motor drive device 21 is mounted on the electric vehicle 11, the existing suspension device can be used, and the development cost can be reduced. In the configuration of the present embodiment, the space in the wheel W is reduced by the volume of the rotary pump 60. However, the effect is slight compared with an increase in the axial dimension of the entire motor unit A, and the suspension is suspended. Does not adversely affect device design.

In particular, in the present embodiment, two intermediate shafts S1 and S2 are disposed between the input shaft 30a and the output shaft 36 of the parallel shaft gear reducer 39, and the second intermediate shaft S2 is selected from the two intermediate shafts S1 and S2. A rotary pump 60 is coupled. The second intermediate shaft S2 positioned on the downstream side in the torque transmission direction is easily disposed at a position further away from the motor unit A than the first intermediate shaft S1 on the upstream side. Therefore, even when the outer diameter of the motor part A is large, it becomes easy to arrange the rotary pump 60 on the outer diameter side of the motor part A as described above. If the rotary pump 60 can be arranged on the outer diameter side of the motor part A, the rotary pump 60 may be coupled to the first intermediate shaft S1.

The parallel shaft gear reducer 39 can be provided with three or more intermediate shafts. Even in that case, it is preferable to connect the rotary pump 60 to any intermediate shaft except the intermediate shaft on the most upstream side in the torque transmission direction. Of course, if it is possible to arrange the rotary pump 60 on the outer diameter side of the motor part A, the number of the intermediate shafts of the parallel shaft gear reducer 39 is one, and the rotary pump 60 is coupled to the intermediate shaft. You can also.

Next, another embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a front view showing a schematic configuration when the in-wheel motor drive device 21 disposed in the inner space of the wheel W of the rear wheel 14 is viewed from the inboard side. 5 is a cross-sectional view taken along the line RR connecting the motor center Oa, the two intermediate shaft centers O1, O2 and the axle center Ob in FIG. 4, and FIG. 6 is a motor view in FIG. FIG. 6 is a cross-sectional view taken along line SS connecting the center Oa and the second intermediate axis center O2.

In the embodiment shown in FIGS. 1 to 3, since the parallel shaft gear reducer 39 performs three-stage deceleration, the reduction ratio between the input shaft 30a and the output shaft 36 tends to increase. As a countermeasure when the reduction ratio between the input shaft 30a and the output shaft 36 is too large, in the embodiment shown in FIGS. 4 to 6, the third intermediate gear 33 and the fourth intermediate gear 34 (see FIG. 1 and FIG. 2) is omitted, and an idler gear 37 is provided on the second intermediate shaft S2, and the idle gear 37 is engaged with the second intermediate gear 32 and the output gear 38, respectively. Similar to the embodiment shown in FIGS. 1 to 3, the rotary pump 60 is coupled to the second intermediate shaft S2.

In this case, the output gear 38 can be provided directly on the outer peripheral surface of the output shaft 36. The hub wheel 53 of the wheel bearing portion C is disposed on the inner periphery of the output shaft 36, and the output shaft 36 and the hub wheel 53 are connected by spline fitting, so that the hub wheel 53 is rotationally driven by the rotation of the output shaft 36. be able to. As the wheel bearing portion C, an inner ring rotation type wheel bearing may be used. Except for the configuration and function described above, the configuration and function of the embodiment shown in FIGS. 4 to 6 are the same as those of the embodiment of FIGS.

Thus, when the gear provided on the intermediate shaft of the parallel shaft gear reducer 39 is constituted by the idle gear 37, no deceleration is performed between the first intermediate shaft S1 and the axle 51. Therefore, the reduction ratio between the input shaft 30a and the output shaft 36 can be reduced, and thereby the degree of freedom in designing the reduction ratio of the parallel shaft gear reducer 39 can be increased. On the other hand, as in the embodiment shown in FIGS. 1 to 3, the second intermediate shaft S2 can be arranged at a position farther from the motor part A than the first intermediate shaft S1, so that it is coupled to the second intermediate shaft S2. It becomes easy to arrange the rotary pump 60 on the outer diameter side of the motor part A. Accordingly, similarly to the embodiment shown in FIGS. 1 to 3, the capacity of the rotary pump 60 can be increased without increasing the axial dimension of the in-wheel motor drive device 21.

In the above description of the embodiment, the radial gap type electric motor 26 is exemplified as the motor portion A, but a motor having an arbitrary configuration can be applied. For example, an axial gap type electric motor including a stator fixed to a casing and a rotor arranged so as to face the inner side in the axial direction of the stator with a gap may be used. In this embodiment, the cycloid pump is exemplified as the rotary pump 60. However, the rotary pump 60 is not limited to this, and is driven by using the rotation of the first intermediate shaft S1 or the second intermediate shaft S2 of the speed reducer unit B. Any rotary pump can be used.

In the above description, the case where the motor unit A is supplied with electric power to drive the motor unit and the power from the motor unit A is transmitted to the rear wheel 14 is shown. On the contrary, the vehicle decelerates. When driving down or going down a hill, the power from the rear wheel 14 side is converted into high-rotation low-torque rotation by the reducer B and transmitted to the motor A, and the motor A generates power. Good. Furthermore, the electric power generated here may be stored in a battery and used later for driving the motor unit A or for operating other electric devices provided in the vehicle.

In this embodiment, as shown in FIGS. 7 and 8, the electric vehicle 11 having the rear wheel 14 as a drive wheel is illustrated, but the front wheel 13 may be a drive wheel or a four-wheel drive vehicle. In the present specification, “electric vehicle” is a concept including all vehicles that obtain driving force from electric power, and includes, for example, a hybrid vehicle.

The present invention is not limited to the above-described embodiments, and can of course be implemented in various forms without departing from the gist of the present invention. It includes the equivalent meanings recited in the claims and the equivalents recited in the claims, and all modifications within the scope.

DESCRIPTION OF SYMBOLS 21 In-wheel motor drive device 25 Motor rotating shaft 30 Input gear 30a Input shaft 31-34 Intermediate gear 35 Output gear 36 Output shaft 37 Idler gear 38 Output gear 39 Parallel shaft gear reducer 60 Rotary pump A Motor part B Reducer part C Wheel Bearing part S1 1st intermediate shaft S2 2nd intermediate shaft W Wheel

Claims

In an in-wheel motor drive device having a motor unit, a speed reducer unit composed of a parallel shaft gear reducer composed of a plurality of gears, a wheel bearing unit, and a rotary pump that pumps lubricating oil,
An intermediate shaft having an intermediate gear is disposed between an input shaft and an output shaft of the reduction gear unit, the rotary pump is driven by the intermediate shaft, and the rotary pump is overlapped in the radial direction with the motor unit to thereby form the motor. An in-wheel motor drive device characterized by being arranged on the outer diameter side of the portion.
The in-wheel motor drive device according to claim 1, wherein the tooth surface of the intermediate gear and the rotary pump are spaced apart in the axial direction.
The parallel shaft gear reducer is provided with a plurality of intermediate shafts, and the rotary pump is driven by an intermediate shaft excluding the intermediate shaft on the most upstream side in the torque transmission direction among the plurality of intermediate shafts. In-wheel motor drive device.
The in-wheel motor drive device according to any one of claims 1 to 3, wherein an intermediate gear provided on an intermediate shaft for driving the rotary pump is an idler gear.