JP2015020483A - In-wheel motor drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an in-wheel motor drive device in which there is no need to form a conventional long oil supply passage and return passage in a housing of an electric motor.SOLUTION: An in-wheel motor drive device comprises: an electric motor A that generates drive force; a speed reducer B that reduces rotation speed of the electric motor A and outputs the reduced speed; and a wheel hub C that transmits an output from the speed reducer B to a wheel. A rotary pump 51 that forcibly circulates lubricant from an oil tank 22c of lubricant provided at a lower part of the speed reducer B to the electric motor A and the speed reducer B is provided at an end part on an inner side of a motor side rotary shaft 24b of the electric motor A, and the rotary pump 51 provided at the end part on the inner side of the motor side rotary shaft 24b of the electric motor A sucks up lubricant pooled in a lower part of a housing 22, and supplies the lubricant from the end part on the inner side of the motor side rotary shaft 24b of the electric motor A to an internal passage 24c provided at the motor side rotary shaft 24b of the electric motor A.

Description

  The present invention relates to an in-wheel motor drive device, and more particularly to an in-wheel motor drive device for circulating lubricating oil by pumping it with a pump.

  The in-wheel motor drive device 101 is installed in an inner space portion of a wheel of an automobile, and as shown in FIG. 9, an electric motor 103 that generates a driving force inside a housing 102 attached to a vehicle body, and a wheel And a speed reducer 105 that decelerates the rotation of the electric motor 103 and transmits it to the wheel hub 104.

  In the in-wheel motor drive device 101 having the above-described configuration, a low torque and high rotation motor is adopted as the electric motor 103 from the viewpoint of compactness of the device. On the other hand, the wheel hub 104 requires a large torque to drive the wheels. For this reason, a cycloid reduction gear that is compact and provides a high reduction ratio is often adopted as the reduction gear 105.

  A speed reducer 105 to which a cycloid speed reducer is applied includes an input shaft 106 having eccentric portions 106 a and 106 b, curved plates 107 a and 107 b arranged on the eccentric portions 106 a and 106 b, and curved plates 107 a and 107 b with respect to the input shaft 106. A plurality of outer peripheral engagement members 108 that engage the outer peripheral surfaces of the curved plates 107a and 107b to cause the curved plates 107a and 107b to rotate, and the curved plates 107a and 107b. And a plurality of inner pins 109 that transmit the rotation motion of the motor to the wheel-side rotation member 110.

    In the in-wheel motor drive device 101 configured as described above, an oil tank 102d for lubricating oil is provided at the lower portion of the housing 102, and the lubricating oil in the oil tank 102d is sucked by the rotary pump 113 from the suction passage 102f, and the electric motor 103 and the reduction gear A lubricating device is provided that supplies lubricating oil to 105 to perform lubrication and cooling (Patent Document 1).

    The lubricating device is provided in the housing 102 with a lubricating oil passage 112a provided in the motor-side rotating shaft 112, a lubricating oil supply port 112b extending from the lubricating oil passage 112a toward the outer diameter surface of the input shaft 106, and a deceleration. A lubricating oil outlet 102b for discharging lubricating oil from the machine 105, a lubricating oil outlet 102b and the lubricating oil passage 112a are connected to each other, and the lubricating oil discharged from the lubricating oil outlet 102b is circulated to the lubricating oil passage 112a. An oil passage 102c and a rotary pump 113 that is disposed in the housing 102 and circulates the lubricating oil using the rotation of the wheel-side rotating member 110 are provided.

  Between the lubricating oil discharge port 102b and the rotary pump 113, an oil tank 102d for temporarily storing lubricating oil is provided at a lower portion of the speed reduction unit housing 102e of the reduction gear 105.

JP 2009-63043 A

  By the way, the rotary pump 113 that forcibly circulates the lubricating oil to the electric motor 103 and the speed reducer 105 is provided at an end portion on the inner side of the wheel side rotating member 110.

  For this reason, in the in-wheel motor drive device 101 of FIG. 9, the lubricating oil sucked in by the rotary pump 113 is passed through the circulating oil passage 102c provided on the upper and rear sides of the housing 102 to the inside of the motor-side rotating shaft 112 of the electric motor 103. It is circulated through the space to the speed reducer 105. The flow of the lubricating oil is indicated by broken arrows.

  Further, a suction passage 102 f from the oil tank 102 d below the housing 102 to the rotary pump 113 needs to be formed in the housing 102 of the electric motor 103.

  When the circulating oil passage 102c and the suction passage 102f having a long oil passage are formed in the housing 102 of the electric motor 103, the oil passage is complicated, and the suction passage 102f may be formed obliquely. The formation cost of the housing 102 of the motor 103 increases.

  Therefore, an object of the present invention is to provide an in-wheel motor drive device that does not require the formation of a circulation oil passage and a suction passage having a long oil passage as in the conventional case in the housing of the electric motor.

In order to solve the above problems, the present invention includes an electric motor that generates a driving force, a speed reducer that decelerates and outputs the rotation of the electric motor, and a wheel hub that transmits the output from the speed reducer to the wheel. In the in-wheel motor drive device, the inner end of the motor-side rotating shaft of the electric motor has a rotary pump that forcibly supplies the lubricating oil to the electric motor and the reducer from the oil tank of lubricating oil provided in the lower part of the reducer The lubricating oil stored in the lower part of the housing of the electric motor is sucked up by the rotary pump provided at the inner side end of the motor side rotating shaft of the electric motor, and the inner side end of the motor side rotating shaft of the electric motor The lubricating oil is supplied to the internal passage provided in the motor side rotating shaft of the electric motor from the section.
Here, the outer side indicates the outside of the vehicle body, that is, the wheel hub side of the in-wheel motor driving device, and the inner side indicates the inside of the vehicle body, that is, the motor side of the in-wheel motor driving device.

  By providing an oil passage for sucking up the lubricating oil stored in the lower part of the housing of the electric motor and an oil passage from the rotary pump to the internal passage provided on the motor side rotating shaft of the electric motor to the rear cover of the electric motor housing, There is no need to form an oil passage in the housing of the electric motor, and the cost can be reduced.

  By providing the rear cover separately from the electric motor housing so as to be removable from the electric motor housing, maintenance of the rotary pump and the like is facilitated.

  By disposing a reduction gear mechanism between the drive shaft of the rotary pump and the motor-side rotary shaft of the electric motor, the durability of the rotary pump can be improved.

  As described above, according to the present invention, since the rotary pump is provided at the end on the inner side of the motor-side rotating shaft of the electric motor, the circulating oil passage for the lubricating oil can be simplified, thereby reducing the cost. Can be planned.

It is a schematic sectional drawing which shows embodiment of the in-wheel motor drive device which concerns on this invention. It is an enlarged view of the reduction gear of FIG. It is sectional drawing of the III-III line | wire of FIG. It is an enlarged view of the eccentric part periphery of FIG. It is the figure which looked at the rotary pump of FIG. 1 from the axial direction. It is a schematic plan view of the electric vehicle which has the in-wheel motor drive device of FIG. It is the figure which looked at the electric vehicle of FIG. 8 from back. It is a schematic sectional drawing which shows other embodiment of the in-wheel motor drive device which concerns on this invention. It is a schematic sectional drawing which shows the conventional in-wheel motor drive device.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
As shown in FIG. 6, an electric vehicle 11 including an in-wheel motor drive device according to an embodiment of the present invention includes a chassis 12, front wheels 13 as steering wheels, drive wheels 14, and left and right drive wheels 14. And an in-wheel motor drive device 21 for transmitting the drive force to each. As shown in FIG. 7, the drive wheel 14 is accommodated in a wheel housing 12a of the chassis 12, and is fixed to the lower portion of the chassis 12 via a suspension device (suspension) 12b. As a mounting form of the in-wheel motor drive device 21, either a front wheel drive system or a four-wheel drive system may be used.

  The suspension device 12b supports the drive 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 drive wheel 14 from the ground by a strut including a coil spring and a shock absorber. Furthermore, a stabilizer that suppresses the inclination of the vehicle body when turning or the like is provided at a connecting portion of the left and right suspension arms. The suspension device 12b is an independent suspension type in which the left and right wheels can be moved up and down independently in order to improve the followability to the road surface unevenness and efficiently transmit the driving force of the driving wheels to the road surface. Is desirable.

  In this electric vehicle 11, it is necessary to provide a motor, a drive shaft, a differential gear mechanism, and the like on the chassis 12 by providing an in-wheel motor drive device 21 that drives the left and right drive wheels 14 inside the wheel housing 12a. This eliminates the need to secure a wide cabin space and control the rotation of the left and right drive wheels.

  As shown in FIG. 1, the in-wheel motor drive device 21 includes an electric motor A that generates a driving force, a speed reducer B that decelerates and outputs the rotation of the electric motor A, and an output from the speed reducer B as driving wheels. The electric motor A and the speed reducer B are accommodated in the housing 22 and are mounted in the wheel housing 12a of the electric vehicle 11 as shown in FIG.

  The electric motor A includes a stator 23 fixed to the housing 22, a rotor 24 disposed at a position facing the inner side of the stator 23 with a radial gap, and a rotor 24 fixedly connected to the inner side of the rotor 24. It is a radial gap motor provided with the input shaft 25 which rotates integrally. The rotor 24 includes a flange-shaped rotor portion 24a and a cylindrical motor-side rotating shaft 24b, and is rotatably supported with respect to the housing 22 by rolling bearings 36a and 36b.

  The input shaft 25 is disposed from the electric motor A to the speed reducer B in order to transmit the driving force of the electric motor A to the speed reducer B, and has eccentric portions 25 a and 25 b in the speed reducer B. One end of the input shaft 25 is joined to the motor-side rotating shaft 24b of the rotor 24 by spline fitting, and is supported by the rolling bearing 36c in the speed reducer B. Further, the two eccentric portions 25a and 25b are provided with a 180 ° phase change in order to cancel out the centrifugal force due to the eccentric motion.

  The speed reducer B is held at a fixed position on the housing 22 and curved plates 26a and 26b as revolving members that are rotatably held by the eccentric portions 25a and 25b, and engages with the outer peripheral portions of the curved plates 26a and 26b. A plurality of outer pins 27 as outer peripheral engagement members, a motion conversion mechanism that transmits the rotation of the curved plates 26a and 26b to the wheel-side rotation member 28, and a counterweight 29 at a position adjacent to the eccentric portions 25a and 25b. Prepare. The reduction gear B is provided with a lubrication device that supplies lubricating oil to the reduction gear B.

  The wheel side rotation member 28 includes a flange portion 28a and a shaft portion 28b. Holes for fixing the inner pins 31 are formed on the end face of the flange portion 28a at equal intervals on the circumference around the rotation axis of the wheel side rotation member 28. The shaft portion 28 b is fitted and fixed to the hub member 32, and transmits the output of the speed reducer B to the drive wheel 14. The flange portion 28a of the wheel side rotation member 28 and the input shaft 25 are rotatably supported by a rolling bearing 36c.

  As shown in FIG. 3, the curved plates 26 a and 26 b have a plurality of corrugations composed of trochoidal curves such as epitrochoids on the outer periphery, and a plurality of through holes 30 a penetrating from one end face to the other end face. Have A plurality of through holes 30a are provided at equal intervals on the circumference centering on the rotation axis of the curved plates 26a, 26b, and receive inner pins 31 described later. Further, the through hole 30b is provided at the center of the curved plates 26a and 26b and is fitted to the eccentric portions 25a and 25b.

  The curved plate 26a is rotatably supported by the rolling bearing 41 with respect to the eccentric portion 25a. As shown in FIG. 4, the rolling bearing 41 is fitted to the outer diameter surface of the eccentric portion 25a, and the inner ring member 42 having an inner raceway surface 42a on the outer diameter surface, and the inner diameter of the through hole 30b of the curved plate 26a. The outer raceway surface 43 formed directly on the surface, a plurality of cylindrical rollers 44 disposed between the inner raceway surface 42a and the outer raceway surface 43, and a retainer (not shown) that keeps an interval between the adjacent cylindrical rollers 44 It is a cylindrical roller bearing provided with. Further, the curved plate 26b is also rotatably supported by the rolling bearing 41.

  As shown in FIGS. 1 and 2, the outer pins 27 are provided at equal intervals on a circumferential track centering on the rotation axis of the input shaft 25. When the curved plates 26a and 26b revolve, the curved waveform and the outer pin 27 engage with each other to cause the curved plates 26a and 26b to rotate. Further, in order to reduce the frictional resistance with the curved plates 26a, 26b, needle roller bearings 27a are provided at the positions of both ends of the outer pin 27.

  The counterweight 29 has a disc shape and has a through-hole that fits with the input shaft 25 at a position off the center. Each counterweight 29 is arranged in order to cancel out the unbalanced inertia couple caused by the rotation of the curved plates 26a and 26b. Arranged at positions adjacent to the portions 25a and 25b with a 180 ° phase shift from the eccentric portion.

  Here, as shown in FIG. 4, if the center point between the two curved plates 26a and 26b is G, the distance between the central point G and the center of the curved plate 26a is the right side of the central point G in FIG. L1, the sum of the mass of the curved plate 26a, the rolling bearing 41, and the eccentric portion 25a is m1, the amount of eccentricity of the center of gravity of the curved plate 26a from the rotational axis is ε1, and the distance between the center point G and the counterweight 29 is L2. Assuming that the mass of the counterweight 29 is m2 and the amount of eccentricity from the rotational axis of the center of gravity of the counterweight 29 is ε2, the relationship satisfies L1 × m1 × ε1 = L2 × m2 × ε2. A similar relationship is also established between the curved plate 26b on the left side of the center point G in FIG.

  As shown in FIGS. 1 and 2, the motion conversion mechanism includes a plurality of inner pins 31 held by the wheel-side rotating member 28 and through holes 30 a provided in the curved plates 26 a and 26 b. The inner pins 31 are provided at equal intervals on a circumferential track centering on the rotational axis of the wheel side rotation member 28, and one axial end thereof is fixed to the wheel side rotation member 28. Further, in order to reduce the frictional resistance with the curved plates 26a, 26b, a needle roller bearing 31a is provided at a position where the curved plates 26a, 26b come into contact with the inner wall surface of the through hole 30a.

  On the other hand, the through hole 30a is provided at a position corresponding to each of the plurality of inner pins 31, and the inner diameter of the through hole 30a is the outer diameter of the inner pin 31 ("the maximum outer diameter including the needle roller bearing 31a"). The same shall apply hereinafter).

  The electric motor A is accommodated in the housing 22. The housing 22 includes a housing body 22e and a rear cover 22d. The reduction gear B is accommodated in the housing 22f.

  The housing 22f of the speed reducer B is provided with a lubricating oil discharge port 22b for dropping and discharging the lubricating oil in the speed reducer B to the lower oil tank 22c.

  The drive shaft 51a of the rotary pump 51 is fixed to the inner side of the motor-side rotary shaft 24b, that is, the end opposite to the speed reducer B.

  The rotary pump 51 is accommodated in a pump case 57 that is detachably attached to the rear cover 22d.

  The pump case 57 is provided with a suction passage 59 continuous to the suction port 55 of the rotary pump 51 and a discharge passage 61 at the discharge port 60 of the rotary pump 51.

  The suction passage 59 of the pump case 57 is connected to a return passage 62 that guides the lubricating oil accumulated at the bottom of the housing body 22e.

  Further, the discharge passage 61 of the pump case 57 is connected to an internal passage 24c formed in the motor side rotating shaft 24b of the electric motor A. The lubricating oil supplied by the rotary pump 51 is discharged by centrifugal force from the supply hole 25e through the internal passage 24c of the motor-side rotary shaft 24b, and lubricates and cools the electric motor A. Further, the lubricating oil that has passed through the internal passage 24c is released by centrifugal force from the supply hole 25c of the input shaft 25 of the speed reducer B, and lubricates and cools the inside of the speed reducer B.

  Here, as shown in FIG. 5, the rotary pump 51 includes an inner rotor 52 that rotates using the rotation of the motor-side rotating shaft 24 b of the electric motor A, and an outer rotor that is driven to rotate as the inner rotor 52 rotates. 53, a cycloid pump including a pump chamber 54, a suction port 55 communicating with the suction passage 59, and a discharge port 56 communicating with the discharge passage 61.

  Inner rotor 52 has a tooth profile formed of a cycloid curve on the outer diameter surface. Specifically, the shape of the tooth tip portion 52a is an epicycloid curve, and the shape of the tooth gap portion 52b is a hypocycloid curve. The inner rotor 52 rotates integrally with the vehicle body side rotation member 28.

  The outer rotor 53 has a tooth profile constituted by a cycloid curve on the inner diameter surface. Specifically, the shape of the tooth tip portion 53a is a hypocycloid curve, and the shape of the tooth gap portion 53b is an epicycloid curve. The outer rotor 53 is rotatably supported by the pump case 57.

  The inner rotor 52 rotates about the rotation center c1. On the other hand, the outer rotor 53 rotates around a rotation center c2 different from the rotation center c1 of the inner rotor. Further, when the number of teeth of the inner rotor 52 is n, the number of teeth of the outer rotor 53 is (n + 1). In this embodiment, n = 5.

  A plurality of pump chambers 54 are provided in the space between the inner rotor 52 and the outer rotor 53. And if the inner rotor 52 rotates using the rotation of the motor side rotating shaft 24b, the outer rotor 53 rotates in a driven manner. At this time, since the inner rotor 52 and the outer rotor 53 rotate about different rotation centers c1 and c2, respectively, the volume of the pump chamber 54 changes continuously. As a result, the lubricating oil flowing in from the suction port 55 is pumped from the discharge port 56 to the discharge passage 61.

As shown in FIGS. 1 and 2, the housing 22f of the speed reducer B is provided with an oil tank 22c for lubricating oil in the lower portion, and the lubricating oil in the oil tank 22c communicates (shares) with the bottom of the housing body 22e. The lubricating oil is sucked by the rotary pump 51 through the return passage 62, and the lubricating oil is supplied to the electric motor A and the speed reducer B to perform lubrication and cooling.
An oil supply hole 25 e for supplying lubricating oil to the electric motor A is provided on the motor-side rotating shaft 24 b of the rotor 24 of the electric motor A.

  As shown in FIG. 1, the wheel hub C includes a hub member 32 fixedly connected to the wheel-side rotating member 28, and a wheel hub bearing 33 that holds the hub member 32 rotatably with respect to the housing 22 f of the speed reducer B. Is provided. The hub member 32 has a cylindrical hollow portion 32a and a flange portion 32b. The drive wheel 14 is fixedly connected to the flange portion 32b by a bolt 32c. A spline and a male screw are formed on the outer diameter surface of the shaft portion 28b of the wheel side rotation member 28. A spline hole is formed in the inner diameter surface of the hollow portion 32 a of the hub member 32. Then, the wheel-side rotating member 28 is fitted to the inner diameter surface of the hub member 32, and the nut 32d is screwed to the female screw at the tip thereof, thereby fastening both of them.

  The wheel hub bearing 33 is fitted to the outer raceway surface formed integrally with the outer diameter surface of the hollow portion 32a of the hub member 32 and the outer diameter surface of the inner side of the hollow portion 32a of the hub member 32. An inner member 33a comprising an inner ring 33b having an inner raceway surface on the outer surface, a double row ball 33c disposed on the outer raceway surface and the inner raceway surface of the inner member 33a, and an inner member 33a. An outer member 33d having inner and outer raceways facing the outer raceway surface and the inner raceway surface on the inner peripheral surface, a retainer 33e that holds a gap between adjacent balls 33c, and a wheel hub It is a double row angular contact ball bearing provided with sealing members 33f and 33g for sealing both axial ends of the bearing 33.

  The outer member 33d of the wheel hub bearing 33 is fixed to the housing 22f by fastening bolts 37.

The operation of the in-wheel motor drive device 21 configured as described above will be described.
The electric motor A receives, for example, electromagnetic force generated by supplying an alternating current to the coil of the stator 23, and the rotor 24 composed of a permanent magnet or a magnetic material rotates. At this time, the rotor 24 rotates at a higher speed as a higher frequency voltage is applied to the coil.

  Thereby, when the motor side rotating shaft 24b connected to the rotor 24 rotates, the curved plates 26a and 26b revolve around the rotation axis of the motor side rotating shaft 24b. At this time, the outer pin 27 engages with the curved waveform of the curved plates 26a and 26b, and causes the curved plates 26a and 26b to rotate in the direction opposite to the rotation of the motor side rotating shaft 24b.

  The inner pin 31 inserted through the through hole 30a comes into contact with the inner wall surface of the through hole 30a as the curved plates 26a and 26b rotate. As a result, the revolving motion of the curved plates 26 a and 26 b is not transmitted to the inner pin 31, but only the rotational motion of the curved plates 26 a and 26 b is transmitted to the wheel hub C via the wheel-side rotating member 28.

  At this time, since the rotation of the motor-side rotating shaft 24b is decelerated by the reduction gear B and transmitted to the wheel-side rotating member 28, it is necessary for the drive wheels 14 even when the low-torque, high-rotation type electric motor A is adopted. It is possible to transmit an appropriate torque.

  Note that the reduction ratio of the reduction gear B configured as described above is calculated as (ZA−ZB) / ZB, where ZA is the number of outer pins 27 and ZB is the number of waveforms of the curved plates 26a and 26b. In the embodiment shown in FIG. 5, since ZA = 12, ZB = 11, the reduction ratio is 1/11, and a very large reduction ratio can be obtained.

  Thus, by adopting the reduction gear B that can obtain a large reduction ratio without using a multi-stage configuration, a compact and high reduction ratio in-wheel motor drive device 21 can be obtained. Moreover, since the frictional resistance is reduced by providing the needle roller bearings 27a and 31a at the positions where they contact the curved plates 26a and 26b of the outer pin 27 and the inner pin 31, the transmission efficiency of the speed reducer B is improved. .

  By adopting the in-wheel motor drive device 21 according to the above embodiment in the electric vehicle 11 shown in FIGS. 6 and 7, the unsprung weight can be suppressed. As a result, the electric vehicle 11 having excellent running stability can be obtained.

  In the embodiment of FIG. 8, the drive shaft 51a of the rotary pump 51 is rotatably supported on the rear cover 22d via the rolling bearings 63a and 63b in parallel with the inner end of the motor side rotary shaft 24b. A reduction gear comprising a small-diameter gear 64a provided on the motor-side rotary shaft 24b and a large-diameter gear 64b provided on the drive shaft 51a between the drive shaft 51a of the motor 51 and the inner end of the motor-side rotary shaft 24b. Connected via mechanism.

  By providing the small-diameter gear 64a of the reduction gear on the motor-side rotary shaft 24b and the large-diameter gear 64b on the drive shaft 51a of the rotary pump 51, the rotation of the drive shaft 51a of the rotary pump 51 is caused by rotation of the motor-side rotary shaft 24b. Is also slowed down. Thus, the durability of the rotary pump 51 can be improved by decelerating the rotation of the drive shaft 51 a of the rotary pump 51.

  Since the other configuration of the embodiment of FIG. 8 is basically the same as that of the first embodiment, the same reference numerals are assigned and redundant description is omitted.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to the thing of embodiment shown in figure. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

DESCRIPTION OF SYMBOLS 11 Electric vehicle 12 Chassis 12a Wheel housing 12b Suspension device 13 Front wheel 14 Drive wheel 21 In-wheel motor drive device 22 Housing 22b Lubricating oil discharge port 22c Oil tank 22d Rear cover 22e Housing main body 22f Housing 23 Stator 24 Rotor 24a Rotor part 24b Motor side rotation Shaft 24c Internal passage 25 Input shaft 25a Eccentric part 25b Eccentric part 25e Oil supply hole 26a Curved plate 26b Curved plate 27 Outer pin 27a Bearing 28 Wheel side rotating member 28a Flange part 28b Shaft part 29 Counterweight 30a Through hole 30b Through hole 31 Inner pin 31a Bearing 32 Hub member 32a Hollow part 32b Flange part 32c Bolt 32d Nut 33 Wheel hub bearing 33a Inner member 33b Inner ring 33c Ball 33d Outer member 33e Cage 33f Sealing member 3 3g Sealing member 36a Rolling bearing 36b Rolling bearing 36c Rolling bearing 37 Fastening bolt 41 Rolling bearing 42 Inner ring member 42a Inner raceway surface 43 Outer raceway surface 51 Rotary pump 51a Drive shaft 52 Inner rotor 52a Tooth tip portion 52b Tooth groove portion 53 Outer rotor 53a Tooth tip portion 53b Tooth groove portion 54 Pump chamber 55 Suction port 56 Discharge port 57 Pump case 59 Suction passage 60 Discharge port 61 Discharge passage 62 Return passage 63a Rolling bearing 63b Rolling bearing 64a Small diameter gear 64b Large diameter gear A Electric motor B Reduction gear C Wheel hub G Center point c1 Center of rotation c2 Center of rotation

Claims (4)

  In an in-wheel motor drive device comprising: an electric motor that generates a driving force; a speed reducer that decelerates and outputs the rotation of the electric motor; and a wheel hub that transmits the output from the speed reducer to a wheel. A rotary pump that forcibly circulates oil to the electric motor and the speed reducer is provided on the inner side of the motor-side rotary shaft of the electric motor, and the electric motor is provided by the rotary pump provided at the inner end of the motor-side rotary shaft of the electric motor. In-wheel characterized in that the lubricating oil stored in the lower part of the housing of the electric motor is sucked up and supplied to an internal passage provided in the motor-side rotary shaft of the electric motor on the inner side of the motor-side rotary shaft of the electric motor. Motor drive device.   An oil passage for sucking up the lubricating oil stored in the lower part of the motor housing and an oil passage from the rotary pump to the internal passage provided on the motor-side rotating shaft of the electric motor are provided in the rear cover of the electric motor housing. The in-wheel motor drive device according to claim 1.   3. The in-wheel motor drive device according to claim 2, wherein the rear cover is provided separately from the housing of the electric motor so as to be removable from the housing of the electric motor. The in-wheel motor drive device according to any one of claims 1 to 3, wherein a reduction gear mechanism is disposed between a drive shaft of the rotary pump and a motor-side rotary shaft of the electric motor.

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