JP2017040339A - Motor drive unit for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure which can surely lubricate an external peripheral engagement member of a cycloid reduction mechanism more than before, in a motor drive unit for a vehicle.SOLUTION: A lubrication circuit of a motor drive unit for a vehicle includes: an axial line oil passage which extends along a motor rotating shaft, and is connected to a motor casing oil passage (55); a motor oil passage which extends to an outside diameter direction from the axial line oil passage, and injects a lubricant into a motor casing cylinder part (22a); an upward opening (71) which is formed at an inside wall face of a pump casing (22p); and a communication oil passage (73) which is formed at the pump casing (22p), and extends toward an external peripheral engagement member (27u) from the upward opening. The lubrication circuit receives the lubricant which is injected from the motor oil passage at the upward opening, and supplies it to the external peripheral engagement member via the communication oil passage.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a vehicle motor drive device for driving wheels, and more particularly to internal lubrication of a reduction gear.

  In an in-wheel motor drive device equipped with a cycloid reducer, for example, Japanese Unexamined Patent Application Publication No. 2014-240666 (Patent Document 1) and Japanese Unexamined Patent Application Publication No. 2015-55343 (Patent Document 2) are techniques for improving internal lubrication of the cycloid reducer. ). In the in-wheel motor drive device of Patent Document 1, a first oil tank is provided at the lower portion of the in-wheel motor drive device, a second oil tank is provided at the upper portion of the speed reducer of the in-wheel motor drive device, and the bottom of the second oil tank. An open / close valve is provided in Normally, the speed reducer is lubricated with the lubricating oil in the first oil tank. When starting to run or running at low speed, the on-off valve is opened to supply the lubricating oil in the second oil tank to the speed reducer.

  The in-wheel motor drive device of Patent Document 2 includes an outer pin of a reduction gear, a needle roller bearing that supports an outer pin end, an outer pin holding hole that holds the outer pin end and the needle roller bearing, and an outer pin. It has a lubricating oil reservoir adjacent to the holding hole. When the oil is accumulated in the lubricating oil reservoir, the needle roller bearing enters an oil bath state, and the needle roller bearing is sufficiently lubricated.

JP 2014-240666 A Japanese Patent Laying-Open No. 2015-55343

  However, the present inventor has found that there is a point to be further improved in the above-described conventional internal lubrication. That is, in patent document 1, since the lubricating oil in the 2nd oil tank arrange | positioned at the upper side is used, when the 2nd oil tank is empty for some reason, it cannot lubricate. In addition, since the lubricating oil is supplied to the second oil tank separately from the lubricating oil for the reduction center shaft lubrication, there is a possibility that the reduction center shaft lubrication becomes insufficient.

  In Patent Document 2, when the components inside the speed reducer rotate, the lubricating oil inside the speed reducer is scraped or scattered, and the splashes of the lubricating oil are collected in the lubricating oil reservoir adjacent to the outer pin holding hole. In view of this, if the lubricating oil is not present inside the speed reduction portion at the beginning of running of the vehicle, the lubricating oil does not accumulate in the lubricating oil reservoir, and the needle roller bearing cannot be lubricated at the beginning of running. There is also a similar concern during low speed travel.

  In view of the above circumstances, an object of the present invention is to provide a technique capable of lubricating an outer pin of a cycloid reduction mechanism more reliably in a vehicle motor drive device than in the past.

  To this end, the present invention provides a vehicle motor drive device comprising a motor unit, a deceleration unit that decelerates the rotation of the motor unit and outputs it to the wheel side, and a lubricating oil circuit that circulates lubricating oil through the deceleration unit. The motor unit includes a motor rotation shaft, a rotor supported by the motor rotation shaft, a stator facing the rotor, and a motor casing that houses the rotor and the stator, and the reduction unit includes the motor rotation shaft. A speed reducer input shaft to which rotation is input, an eccentric portion eccentrically coupled to the speed reducer input shaft, an inner periphery and an outer periphery, and the inner periphery is attached to the outer periphery of the eccentric portion so as to be relatively rotatable, and the speed is reduced. A revolving member that performs a revolving motion around the axis of the speed reducing portion input shaft as the portion input shaft rotates, an outer periphery engaging member that engages with the outer periphery of the revolving member to cause the revolving motion of the revolving member, Near the inner periphery of the member A motion conversion mechanism provided to extract the rotational motion of the revolution member, a speed reducer output shaft for outputting the rotation extracted by the motion conversion mechanism to the wheel side, the eccentric portion, the revolution member, the outer peripheral engagement member, and the motion conversion It has a speed reducer casing that houses the mechanism. The lubricating oil circuit includes an oil tank that collects lubricating oil inside the speed reduction unit, an oil pump that sucks lubricating oil from the oil tank and discharges it to the speed reduction unit side, and a discharge port of the oil pump provided in the motor casing. Motor casing oil passage extending from the motor to the motor rotation shaft, an axial oil passage extending along the motor rotation shaft and connected to the motor casing oil passage, extending from the axial oil passage in the outer diameter direction, and injecting lubricating oil into the motor casing A rotor oil passage, an upward opening that is provided on the inner wall surface of the motor casing and receives lubricating oil injected from the rotor oil passage, and a communication oil passage that is provided in the motor casing and extends from the upward opening toward the outer peripheral engagement member including.

  According to the present invention, since the upward opening of the lubricating oil circuit opens upward, the falling splash of lubricating oil is received. Further, since the communication oil passage of the lubricating oil circuit extends from the upward opening of the motor part toward the outer peripheral engaging member disposed on the upper side among the plurality of outer peripheral engaging members of the speed reducing part, the lubricating oil received by the upward opening is received. It can supply to the outer periphery engaging member arrange | positioned above the deceleration part input shaft. Therefore, even when there is little lubricating oil to the speed reduction part, such as at the start of operation or low speed operation, the outer peripheral engagement member of the speed reduction part can be sufficiently lubricated. The outer peripheral engagement member is not particularly limited, and may be, for example, a cylindrical pin called an outer pin, or another shape.

  The outer peripheral engagement member of the speed reduction unit may be any member that contacts the outer periphery of the revolution member, and the support structure of the outer peripheral engagement member is not particularly limited. As a preferred embodiment of the present invention, the outer peripheral surface of the end portion of the outer peripheral engagement member is rotatably supported via a rolling bearing. According to this embodiment, the outer peripheral engaging member contacts the revolving member while rotating, and the rolling bearing of the outer peripheral engaging member is lubricated by the lubricating oil received by the upward opening, so that the friction loss is reduced.

  Since the rotor of the motor unit rotates at a high speed, the lubricating oil injected from the rotor oil passage is directed in the outer diameter direction by centrifugal force and collides with the inner periphery of the stator and the motor casing. As a preferred embodiment of the present invention, the motor casing includes a motor casing cylindrical portion and a motor casing disc portion covering the end of the motor casing cylindrical portion, and an upper inner wall surface of the motor casing cylindrical portion is an axis of the motor casing cylindrical portion. It is formed in an inclined surface that gradually increases in diameter from the center to the end, the upward opening is provided in the motor casing disk part, and the inner wall surface of the motor casing disk part continues upward from the upward opening. Connect with inclined surface. According to this embodiment, since the inner wall surface of the motor casing disk portion is continuously connected upward from the upward opening to the inclined surface of the motor casing cylindrical portion, the splash of lubricating oil colliding with the inclined surface is guided to the upward opening. be able to. Therefore, sufficient lubricating oil can be supplied to the outer peripheral engagement member. As another embodiment of the present invention, the inner peripheral surface of the motor casing cylindrical portion may have a constant inner diameter from the axial center to the end of the motor casing cylindrical portion.

  As a further preferred embodiment of the present invention, the communication oil passage is connected to a tank for storing lubricating oil received in the upward opening. According to this embodiment, when the upward opening receives a large amount of lubricating oil, the lubricating oil can be temporarily stored in the tank, and the lubricating oil can gradually flow from the tank to the outer peripheral engagement member side. Therefore, the outer peripheral engagement member can be continuously lubricated. As another embodiment of the present invention, a communication oil path may be provided from the upward opening to the outer peripheral engagement member without providing a tank.

  Although the number of upward openings is not particularly limited, as an embodiment of the present invention, a plurality of upward openings are arranged in the circumferential direction about the axis. According to this embodiment, a large amount of lubricating oil can be received. In another embodiment of the present invention, there may be only one upward opening.

  The vehicle motor drive device of the present invention is mounted on the vehicle body or attached below the vehicle body and is drivingly coupled to the wheels. As one embodiment, the vehicle motor drive device further includes a wheel hub bearing that includes a wheel hub coupled to the output shaft of the speed reduction unit and rotatably supports the wheel hub. According to this embodiment, the vehicle motor drive device can be housed in the wheel as a so-called in-wheel motor drive device.

  As described above, according to the present invention, the lubricating performance of the outer peripheral engagement member can be improved as compared with the conventional one in the cycloid reduction mechanism that decelerates the rotation of the motor and transmits it to the wheels.

1 is a longitudinal sectional view showing a vehicle motor drive device according to an embodiment of the present invention. It is a cross-sectional view which shows the same embodiment. It is a longitudinal cross-sectional view which expands and shows the same embodiment. It is a top view which takes out and shows upward opening. It is a cross-sectional view (VV of FIG. 3) which shows the upward opening provided in the motor casing. It is a cross-sectional view (VI-VI of FIG. 3) which shows the upward opening provided in the motor casing. It is a cross-sectional view (VII-VII of FIG. 3) which shows the communication channel | path provided in the deceleration part casing. It is a fragmentary longitudinal cross-sectional view which expands and shows the part containing upward opening among other embodiments of this invention. It is a top view which takes out upward opening from other embodiments. It is a front view which shows upward opening of other embodiment. It is a cross-sectional view showing an upward opening of another embodiment. It is a cross-sectional view which shows the communication channel | path of other embodiment. It is a longitudinal cross-sectional view which shows typically the motor drive device for vehicles which becomes another one Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing a vehicle motor drive device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing the embodiment. The in-wheel motor drive device 21 is a kind of vehicle motor drive device that drives the wheels of an electric vehicle such as an electric vehicle or a hybrid vehicle, and includes a motor unit A that generates a driving force as shown in FIG. A speed reduction part B that decelerates and outputs the rotation of A and a wheel hub bearing part C that transmits the output from the speed reduction part B to the wheels are provided. The motor part A, the speed reduction part B, and the wheel hub bearing part C are arranged coaxially along the axis O of the in-wheel motor drive device 21 in this order. In the following description, the direction from the motor part A toward the wheel hub bearing part C is also referred to as the axis O direction, and the direction from the wheel hub bearing part C to the motor part A is also referred to as the other axis O direction.

  The in-wheel motor drive device 21 is attached to the body of an electric vehicle using an electric motor as a drive source or a hybrid vehicle using an electric motor and an engine as drive sources via a suspension device (not shown). Such electric vehicles and hybrid vehicles are passenger cars, and can travel on public roads at high speed in the same manner as general engine cars.

  The in-wheel motor drive device 21 is disposed in a space area in a road wheel of a wheel (not shown) and drives the wheel. The axis O of the in-wheel motor drive device 21 coincides with the axis of the wheel and extends substantially horizontally in the vehicle width direction.

  The motor part A includes a motor casing cylindrical part 22a, a pump casing 22p, and a motor rear cover 22t as motor casings that form an outer shell of the motor part. The pump casing 22p is a disk (motor casing disk part) that covers one end opening in the axis O direction of the motor casing cylindrical part 22a, and the motor rear cover 22t is a disk that covers the other end opening in the axis O direction of the motor casing cylindrical part 22a. It is. Moreover, the deceleration part B has the cylindrical deceleration part casing 22b which forms the outline of a deceleration part. The motor rear cover 22t and the motor casing cylindrical part 22a of the motor part A are coupled to each other by bolts and the like, the pump casing 22p is integrally formed with the motor casing cylindrical part 22a, and the pump casing 22p and the speed reduction part casing 22b are mutually coupled by bolts and the like. As a whole, one cylindrical casing 22 is formed. As described above, the casing 22 includes a plurality of casing members or casing portions. Then, the outer ring member 33 a of the wheel hub bearing portion C is attached and fixed to the casing 22.

  The motor part A includes a stator 23 that is fixed to the inner periphery of the motor casing cylindrical part 22a, a rotor 24 that is disposed on the inner side of the stator 23 via a gap that is radially open, and an inner side of the rotor 24. A radial gap motor including a motor rotating shaft 35 that is connected and fixed to the rotor 24 and rotates integrally with the rotor 24. Alternatively, although not shown, the motor part A may be an axial gap motor.

  The motor casing cylindrical portion 22a is centered on the axis O of the motor rotation shaft 35 and extends in this axial direction. The pump casing 22p, which is a part of the casing 22, is a substantially disc-shaped partition wall, is integrally formed at one end of the motor casing cylindrical portion 22a, and is connected to the speed reduction portion B at one end in the axis O direction of the motor portion A. A boundary is formed, and one end portion of the motor rotating shaft 35 is rotatably supported via the rolling bearing 37. Further, a suction oil passage 52, an oil pump 51, and a discharge oil passage 54 of the lubricating oil circuit are formed inside the wall thickness of the pump casing 22p. The lubricating oil circuit will be described later. The motor rear cover 22t, which is a part of the casing 22, has a substantially disk shape, is abutted against and fixed to the other end of the motor casing cylindrical portion 22a, and is the end surface of the motor portion A at the other end in the axis O direction of the motor portion A. And the other end of the motor rotating shaft 35 is rotatably supported via the rolling bearing 36. The motor rear cover 22t is an end portion of the motor portion A and also an end portion on the inner side in the vehicle width direction of the in-wheel motor drive device 21.

  One end of the motor rotation shaft 35 extending along the axis O is coupled to a speed reduction portion input shaft 25 that is rotatably provided inside the speed reduction portion B. This coupling is spline fitting or serration fitting, and the tapered speed reducing portion input shaft 25 is inserted into and engaged with the end opening of the motor rotating shaft 35 formed in a tubular shape.

  The speed reduction part B is a cycloid speed reducer coaxially arranged on one side of the motor part A in the axis O direction, and is a cylindrical speed reduction part casing 22b and an outer pin attached and fixed to the inner peripheral surface of the speed reduction part casing 22b. A holding member 45, a speed reduction portion input shaft 25 extending along the axis O, a pair of eccentric portions 25a and 25b formed on the speed reduction portion input shaft 25, and rotatably held by the respective eccentric portions 25a and 25b. A pair of curved plates 26a and 26b as revolution members, a plurality of outer pins 27 as outer peripheral engaging members that engage with the outer peripheral portions of the curved plates 26a and 26b, and a speed reducing portion output shaft 28 extending along the axis O The curved portions 26a and 26b are attached to a gap between the pair of curved plates 26a and 26b and a plurality of inner pins 31 serving as inner engagement members that are coupled to the speed reducing portion output shaft 28 and extract the rotational movement of the curved plates 26a and 26b. A 26a, a collar member 29 for preventing the inclination of the contact with the curved plate to the end surface of the 26b, and a reinforcing member 61 for fixing the ends of the motor part A side of the plurality of inner pins 31.

  The speed reduction part casing 22b is disposed coaxially with the axis O and has a smaller outer diameter than the motor casing cylindrical part 22a. The outer periphery of the speed reduction part casing 22b is rotatably connected to a suspension member (not shown) of the suspension device. The wheel load (also referred to as the vehicle body weight) is transmitted to the road surface through these suspension members, the speed reduction portion casing 22b, the wheel hub bearing portion C, and the wheels.

  The speed reduction unit input shaft 25 extends along the axis O of the motor rotation shaft 35, and the end of the speed reduction unit input shaft 25 on the side closer to the motor unit A of both ends thereof is coupled to one end of the motor rotation shaft 35. . The end of the speed reduction part input shaft 25 on the side far from the motor part A is rotatably supported by the end of a speed reduction part output shaft 28 described later via a rolling bearing 39. A pair of eccentric portions 25 a and 25 b are formed eccentrically from the axis O on the outer periphery of the deceleration portion input shaft 25. The speed reducer input shaft 25 is rotatably supported by the reinforcing member 61 by the rolling bearing 38 on the side closer to the motor part A than the eccentric parts 25a and 25b.

  Each eccentric part 25a, 25b is a disk shape, and is eccentric from the axis O and is provided on the deceleration part input shaft 25. Further, the eccentric parts 25a and 25b form a pair of two and are arranged apart from each other in the direction of the axis O, and are provided with a phase difference of 180 ° in the circumferential direction so as to cancel out vibrations generated by the centrifugal force due to the eccentric movement. It has been. The motor rotation shaft 35 and the speed reduction part input shaft 25 constitute a motor side rotation member that transmits the driving force of the motor part A to the speed reduction part B, and rotate integrally.

  Referring to FIG. 2, curved plate 26b has a disc shape, and its outer peripheral portion is formed in a waveform. Specifically, the outer peripheral portion of the curved plate 26 b is a plurality of curved concave portions formed of a trochoidal curve such as an epitrochoid and recessed in the radial direction, and meshes with the outer pin 27. The curved plate 26b has a plurality of through holes 30a and 30b penetrating from one end face to the other end face. A plurality of through holes 30a are provided at equal intervals on the circumference centering on the rotation axis X of the curved plate 26b, and receive the inner pins 31. The through hole 30b is centered on the rotation axis X of the curved plate 26b and is the inner periphery of the curved plate 26b. The curved plate 26b is attached to the outer periphery of the eccentric portion 25b so as to be relatively rotatable.

  The inner pin 31 includes a needle roller bearing, and includes an inner pin main body 31a, a plurality of needle rollers 31b as rolling elements, and a bearing outer ring 31c as an inner pin outer ring rotatably supported by the inner pin. The inner pin main body 31a passes through the bearing outer ring 31c, and the needle rollers 31b are disposed in an annular space between the inner pin main body 31a and the bearing outer ring 31c. Since the outer diameter of the bearing outer ring 31c is sufficiently smaller than the inner diameter of the through hole 30a, a part of the outer peripheral surface of the bearing outer ring 31c contacts the hole wall surface of the through hole 30a, and the remaining portion of the outer peripheral surface of the bearing outer ring 31c is It is away from the hole wall surface of the through hole 30a. In this state, the bearing outer ring 31c rolls and rotates along the hole wall surface of the through hole 30a.

  The curved plate 26b is rotatably supported by the rolling bearing 41 with respect to the eccentric portion 25b. In order to facilitate understanding, a part of the rolling bearing 41 in the circumferential direction is shown in FIG. The rolling bearing 41 includes a plurality of rollers 44 disposed between an annular inner ring member 42 having an inner raceway surface 42a on the outer diameter surface and a hole wall surface of the through-hole 30b serving as the outer raceway surface. And a cylindrical roller bearing provided with a cage (not shown) that holds the interval between the rollers 44 adjacent in the circumferential direction. Alternatively, it may be a deep groove ball bearing. The inner diameter surface of the inner ring member 42 is fitted to the outer diameter surface of the eccentric portion 25b. The inner ring member 42 further includes a hole 43 that is located on the inner raceway surface 42a and penetrates in the radial direction and a pair of flanges that face each other across the inner raceway surface 42a. The hole 43 connects the inside of the eccentric portion 25b to a branch oil passage 58b extending in the direction perpendicular to the axis O. The same applies to the curved plate 26a.

  A plurality of outer pins 27 are cylindrical members that are provided at equal intervals on a circumferential track centered on the axis O of the motor-side rotating member and extend parallel to the axis O as shown in FIG. When the pair of curved plates 26a and 26b revolve around the axis O, the curved concave portions on the outer periphery of the curved plates 26a and 26b and the outer pin 27 are engaged with each other as shown in FIG. Rotation motion is caused in 26a and 26b.

  The outer pin 27 disposed inside the speed reduction unit casing 22b may be directly connected and fixed to the inner wall surface of the speed reduction unit casing 22b. However, the outer pin 27 is attached and fixed to the inner wall surface of the speed reduction unit casing 22b. It is held by the holding member 45. More specifically, as shown in FIG. 1, both axial ends of the outer pin 27 are rotatably supported by needle roller bearings 27 a (rolling bearings) attached to the outer pin holding member 45.

  The outer pin holding member 45 has a cylindrical shape and is arranged coaxially with the axis O. A pair of inward flange portions 45 f are formed at both ends of the cylindrical portion of the outer pin holding member 45. Each inward flange portion 45f is formed with a plurality of through holes that receive the end portions of the outer pins 27 and the needle roller bearings 27a at intervals in the circumferential direction. Thus, by attaching the outer pin 27 to the outer pin holding member 45 via the rolling bearing so as to be rotatable and rotatable, the contact resistance due to the engagement with the curved plates 26a and 26b can be reduced. A pair of ring plates 27 c and 27 d are disposed adjacent to both end faces of the outer pin holding member 45. The ring plates 27c and 27d are annular discs centered on the axis O, and face the end surfaces of all the outer pins 27 as shown in FIG.

  The speed reduction part output shaft 28 has a large-diameter flange part 28b at the end part on the motor part A side and a shaft part 28d on the wheel hub bearing part C side. A small-diameter flange portion 28c is formed at a connection portion between the large-diameter flange portion 28b and the shaft portion 28d. At the center of the large-diameter flange portion 28b, a circular concave portion 34 that receives one end of the speed reduction portion input shaft 25 is formed, and a rolling bearing 39 is disposed in the circular concave portion 34. The large-diameter flange portion 28b is formed with a hole for fixing one end portion of the inner pin 31 at equal intervals on the circumference centering on the axis O of the reduction portion output shaft 28. Since the inner pin 31 is provided near the inner periphery of the curved plates 26 and 26b and engages with the curved plates 26 and 26b, it is also referred to as an inner engagement member. The inner pin 31 and the through hole 30a constitute a motion conversion mechanism. The function of the motion conversion mechanism will be described later.

  A reinforcing member 61 is provided at the other end of the inner pin 31 on the side away from the large diameter flange portion 28b. The reinforcing member 61 is a flange-shaped large-diameter disc portion 61b that is coupled and fixed to the tips of the plurality of inner pins 31 inside the speed reduction portion B, and is coaxially formed adjacent to the large-diameter disc portion 61b. A small-diameter disk part 61c having a smaller diameter than the part 61b and a smaller-diameter cylindrical part 61d extending from the inner peripheral edge of the small-diameter disk part 61c to the motor part A are included. The large-diameter disc portion 61b is centered on the axis O, the small-diameter disc portion 61c is disposed closer to the motor portion A than the large-diameter disc portion 61b, and the cylindrical portion 61d is directed from the small-diameter disc portion 61c toward the motor portion A. Extending along the axis O.

  The load applied to a part of the inner pins 31 from the two curved plates 26a, 26b is all of the inner diameter via the large-diameter disk portion 61b of the reinforcing member 61 and the large-diameter flange portion 28b of the reduction portion output shaft 28. Since it is supported by the pins 31, the stress acting on each inner pin 31 can be reduced and the durability can be improved. The tip of the cylindrical portion 61d is inserted into the oil pump 51 to drive the oil pump 51. A rolling bearing 38 is attached to the inner peripheral surface of the small-diameter disk portion 61c, and the rolling bearing 38 supports the speed reduction portion input shaft 25 rotatably.

  Since the reinforcing member 61 is connected to the speed reducing unit output shaft 28 via the inner pin 31, the reinforcing member 61 rotates integrally with the speed reducing unit output shaft 28. The speed reduction part output shaft 28 and the reinforcing member 61 constitute a wheel side rotation member that transmits the driving force of the speed reduction part B to the wheel hub 32. Although not shown in FIG. 1, the wheel hub 32 is connected to the wheel by a bolt 32c.

  A small-diameter cylindrical portion 45 c having a smaller diameter than the outer diameter of the outer pin holding member 45 is extended on the inner periphery of the inward flange portion 45 f of the outer pin holding member 45. The small-diameter cylindrical portion 45c is provided on each of the pair of inward flange portions 45f and extends away from each other.

  Rolling bearings 62 and 64 are provided on the inner peripheral surfaces of the pair of small diameter cylindrical portions 45c, respectively. The rolling bearings 62 and 64 rotatably support the wheel side rotating member. Specifically, the rolling bearing 62 is fitted to the outer diameter surface of the small-diameter disk portion 61 c of the reinforcing member 61 to rotatably support the reinforcing member 61, and the rolling bearing 64 is a small-diameter flange portion of the speed reduction unit output shaft 28. The reduction gear output shaft 28 is rotatably supported by fitting to the outer diameter surface 28c. The rolling bearing 62 is disposed on the side close to the motor part A, and the rolling bearing 64 is disposed on the side close to the wheel hub bearing part C.

  The wheel hub bearing portion C is a rolling bearing having an inner ring 33c, a wheel hub 32 as a rotating shaft, a plurality of rolling elements 33, and an outer ring member 33a as a non-rotating member. The wheel hub 32 is coaxially arranged on one side of the speed reduction unit output shaft 28 in the axis O direction, and is connected and fixed to the speed reduction unit output shaft 28. The outer ring member 33 a is fixed to one end of the speed reduction unit casing 22 b with a bolt 33 b, and the inner ring 33 c is fitted and fixed to the outer peripheral surface of the wheel hub 32. The wheel hub bearing portion C is a double-row angular contact ball bearing having a large number of rolling elements 33 in two rows, and is arranged between the outer ring member 33a and the inner ring 33c on the side where the rolling elements 33 in the first row are close to the speed reduction portion B. The second row of rolling elements 33 is disposed between the outer ring member 33 a and the wheel hub 32 on the side far from the speed reduction portion B. The outer ring member 33a is made of steel from the viewpoint of wear resistance and durability. On the other hand, the casing 22 is made of a light metal such as aluminum from the viewpoint of weight reduction.

  A sealing material 33s and a sealing material 33t are provided in the annular gap between the outer ring member 33a and the inner ring 33c. The sealing material 33 s blocks between the wheel hub bearing portion C and the speed reduction portion B and seals the internal space of the speed reduction portion B. The sealing material 33t blocks between the wheel hub bearing portion C and the outer space of the in-wheel motor drive device 21. Thus, the sealing materials 33s and 33t are arranged at both ends of the outer ring member 33a, respectively, and seal the annular space of the wheel hub bearing portion C.

  The wheel hub 32 includes a cylindrical hollow portion 32a and a wheel mounting flange portion 32b that protrudes radially outward from one end of the hollow portion 32a. The shaft portion 28d is spline-fitted (including serration fitting; the same applies hereinafter) to the center hole of the hollow portion 32a. An inner raceway surface that is in rolling contact with the second row of rolling elements 33 is directly formed on the outer peripheral surface of the hollow portion 32a. A wheel load wheel not shown in FIG. 1 is connected and fixed to the wheel mounting flange portion 32b by a bolt 32c. A road wheel (not shown) accommodates at least one side of the in-wheel motor drive device 21 in the axis O direction, specifically, the wheel hub bearing portion C.

  With reference to FIG. 1 and FIG. 2, the operation principle of the in-wheel motor drive device 21 having the above configuration will be described in detail.

  In the motor part A, for example, by supplying an alternating current to the coil of the stator 23, the rotor 24 composed of a permanent magnet or a magnetic material rotates. Thereby, when the motor rotating shaft 35 connected to the rotor 24 rotates, the curved plates 26a and 26b revolve around the axis O of the motor side rotating member. At this time, the outer pin 27 is engaged with the curved concave portions formed on the outer circumferences of the curved plates 26a and 26b while rolling, and rotates the curved plates 26a and 26b in the direction opposite to the rotation of the motor side rotating member. Exercise.

  The inner pin 31 inserted through each through hole 30a is sufficiently thinner than the inner diameter of the through hole 30a, and abuts against the hole wall surface of the through hole 30a as the curved plates 26a and 26b rotate (see FIG. 2). As a result, the revolving motion of the curved plates 26a and 26b is not transmitted to the inner pin 31, but only the rotational motion of the curved plates 26a and 26b is transmitted to the wheel hub bearing portion C via the speed reduction portion output shaft 28.

  At this time, the speed reduction part output shaft 28 arranged coaxially with the axis O takes out the rotation of the curved plates 26 a and 26 b as the output axis of the speed reduction part B. As a result, the rotation of the speed reducer input shaft 25 is decelerated by the speed reducer B and transmitted to the speed reducer output shaft 28. Therefore, even when the low torque, high rotation type motor unit A is employed, the torque is increased. Thus, it is possible to transmit the necessary torque to the drive wheels.

  Since the inner pin 31 is loosely fitted in the through hole 30a, even if the through hole 30a rotates at a high speed around the axis O, the revolution movement of the revolution member is not transmitted to the inner pin 31. On the other hand, when the through hole 30a rotates at a low speed around the rotation axis X, the rotation motion of the revolving member is transmitted to the inner pin 31. Thus, the through hole 30a and the inner pin 31 constitute a motion conversion mechanism, take out the rotational motion of the curved plates 26a, 26b, and convert it into rotational motion around the axis O of the speed reducing portion input shaft 25, thereby converting the wheel hub bearing. Output to part C. In the present embodiment, the through hole 30a is provided in the revolution member and the inner pin 31 is provided in the speed reduction unit output shaft 28. However, as a modification not shown, the through hole 30a may be provided in reverse.

Note that the reduction ratio of the speed reduction unit B having the above-described configuration is calculated as (Z _A −Z _B ) / Z _B where Z _{A is} the number of outer pins 27 and Z _B is the number of waveforms of the curved plates 26a and 26b. The In the embodiment shown in FIG. 2, since Z _A = 12 and Z _B = 11, the reduction ratio is 1/11, and a very large reduction ratio can be obtained. In this way, by adopting the speed reduction unit B that can obtain a large speed reduction ratio without using a multi-stage configuration, the in-wheel motor drive device 21 having a compact and high speed reduction ratio can be obtained. By employing the in-wheel motor drive device 21 according to the present embodiment in an electric vehicle, the unsprung weight can be suppressed. As a result, an electric vehicle with excellent running stability can be obtained.

  Next, the lubricating oil circuit of this embodiment will be described.

  As shown in FIG. 1, an oil tank 53 is disposed below the in-wheel motor drive device 21. The oil tank 53 is integrally formed at the lower portion of the speed reduction unit casing 22b. The lower end portion of the suction oil passage 52 provided inside the wall thickness of the pump casing 22 p extends to the bottom surface of the oil tank 53.

  The oil pump 51 provided inside the wall thickness of the pump casing 22p is connected to the suction oil passage 52 and the discharge oil passage 54, and the lubricating oil is supplied from the oil tank 53 provided in the lower part of the speed reduction portion B through the suction oil passage 52. The high pressure lubricating oil is discharged from the suction and discharge oil passage 54. The discharge oil passage 54 is provided in the wall thickness of the motor casing cylindrical portion 22a and extends in the axial direction, the oil passage 56 is provided in the wall thickness of the motor rear cover 22t and extends in the radial direction, and a tubular shape. An axial oil passage 57 provided inside the motor rotation shaft 35 and the speed reduction portion input shaft 25 and extending along the axis O, and a branch oil passage 58a and an eccentric portion extending radially outward from the axis O in the eccentric portion 25a. A branch oil passage 58b extending in the same manner in 25b and a hole 43 (see FIG. 2) drilled in the inner ring member 42 fitted to the outer periphery of each of the eccentric portions 25a and 25b are sequentially connected. Further, an opening 58 c connected to the circular recess 34 is provided at the tip of the axial oil passage 57.

  The lubricating oil discharged from the oil pump 51 flows through these oil passages 54, 55, 56, 57, 58 a (58 b), the opening 58 c, and the hole 43 in order, and the inside of the speed reduction part B (rolling bearings 38, 39, 41). , 62, 64, curved plates 26a, 26b, inner pin 31, outer pin 27, collar member 29, etc.) are lubricated and cooled. The lubricating oil after lubrication falls in the internal space of the speed reduction part B, and then passes through the vertical hole 65 penetrating the lower part of the speed reduction part casing 22b in the vertical direction and is received by the oil tank 53.

  The lubricating oil branches off from the axial oil passage 57, flows through the rotor oil passage 59 formed in the rotor 24, is injected into the internal space L, and is applied to the stator 23 to cool the inside of the motor part A and roll. Lubricate the bearings 36 and 37. The lubricating oil after lubrication falls in the internal space L of the motor part A and collects in the lower part of the internal space L. Lubricating oil collected in the lower part of the internal space L flows along the inner wall surface of the motor casing and flows down the discharge hole 66 penetrating the lower part of the pump casing 22p in the direction of the axis O, and is received by the oil tank 53. Since the oil tank 53 is disposed below the motor part A and the speed reduction part B, the lubricating oil naturally flows down the vertical hole 65 and the discharge hole 66.

  The lubricating oil stored in the oil tank 53 due to falling and natural flow is sucked again by the oil pump 51 and circulates inside the in-wheel motor drive device 21. As described above, the in-wheel motor drive device 21 according to the present embodiment includes the axial center oil supply type lubricating oil circuit. Lubricating oil that flows through the lubricating oil circuit flows radially outward from an axial oil passage 57 disposed at the shaft center of the motor part A and the speed reduction part B to lubricate the motor part A and the speed reduction part B.

  In the present embodiment, in addition to the axial center oil supply by the axial oil passage 57 described above, the oil passage is captured in the internal space L in the oil atmosphere and fed from the motor portion A to the speed reduction portion B. , An upward opening 71, a connecting oil passage 73, a tank 74, a connecting hole 75, and a through hole 45h. Such a lubricating oil circuit will be described below.

  FIG. 3 is an enlarged longitudinal sectional view showing the encircled portion indicated by the alternate long and short dash line in FIG. As shown in FIG. 3, the upper part of the inner wall surface of the motor casing cylindrical portion 22a is an inclined surface that gradually becomes larger in diameter toward the pump casing 22p from the central portion in the axis O direction of the motor casing cylindrical portion 22a on the pump casing 22p side. 22 s. The inclined surface 22s is a tapered surface continuous with the inner wall surface of the pump casing 22p.

  Comparing the inner wall surface of the pump casing 22p defining the inner space L with the central portion adjacent to the rolling bearing 38 and the peripheral portion adjacent to the motor casing cylindrical portion 22a, the central portion is directed to the inner space L rather than the peripheral portion. The shape is protruding. An overhang member 72 constituting an upward opening 71 is attached and fixed to the peripheral edge portion of the inner wall surface of the pump casing 22p that is recessed from the center portion. The curved wall surface 22r of the pump casing 22p is continuously connected upward to the inclined surface 22s from the upward opening 71. The curved wall surface 22r is an inner wall surface curved in a concave shape as shown in FIG.

  FIG. 4 is a plan view showing the protruding member 72 that forms the upward opening 71. 5 is a front view showing an overhang member 72 provided in the pump casing 22p, FIG. 6 is a cross-sectional view showing an upward opening 71 provided in the pump casing 22p, and FIG. It is a cross-sectional view which shows the provided communication oil path, and FIGS. 5-7 represents the state seen from the axis O direction other side. The overhang member 72 is disposed above the axis O and overhangs from the inner wall surface of the pump casing 22p.

  In this case, the plurality of outer pins 27 are arranged at intervals in the circumferential direction with the axis O as the center. For this reason, as shown in FIG. 2, the plurality of outer pins 27 are substantially the same height as the one outer pin arranged at the lowermost portion and the axis O extending along the axis oil passage 57 in the inner space of the speed reduction portion casing 22 b. It includes two outer pins arranged at the upper position and one outer pin arranged at the top. In the following description, the uppermost outer pin 27 is also referred to as an outer pin 27u with a suffix u.

  Returning to FIG. 3, the overhang member 72 of the present embodiment is disposed further above the outer pin 27 u disposed at the top of the plurality of outer pins 27. The overhang member 72 includes a bottom portion 72b and a wall portion 72w standing on the bottom portion 72b. A through hole 76 parallel to the axis O is formed in the bottom 72b. A coupling tool such as a bolt is passed through the through hole 76, and the coupling tool securely attaches and fixes the overhang member 72 to the pump casing 22p. Alternatively, although not illustrated, the overhang member 72 may be integrally formed with the pump casing 22p.

  The wall portion 72w of the overhang member 72 extends horizontally along the edge of the bottom portion 72b, and is connected to the inner wall surface of the pump casing 22p at both ends of the wall portion 72w. Thereby, the overhang member 72 defines the upward opening 71. The upward opening 71 is connected to the communication oil passage 73 at the height of the bottom portion 72b.

  The communication oil passage 73 extends in parallel with the axis O, penetrates the pump casing 22p, and communicates with the tank 74 provided inside the wall thickness of the speed reduction portion casing 22b and the upward opening 71. The tank 74 extends in the direction of the axis O so as to extend along the cylindrical speed reducer casing 22b. Further, when viewed in a cross section perpendicular to the axis O, the tank 74 of the present embodiment has an arc shape as shown in FIG. 7 and is relatively high at the circumferential center and relatively low at both circumferential sides. A communication hole 75 is formed at the bottom of the center of the tank 74 in the circumferential direction. The communication hole 75 extends in the vertical direction, and communicates between the tank 74 and the inside of the speed reduction unit B.

  A through hole 45 h is formed in the cylindrical portion of the outer pin holding member 45. The through-hole 45 h penetrates the upper part of the outer pin holding member 45 in the vertical direction and aligns in the vertical direction following the connection hole 75. The lower end of the through hole 45h is directed to the center of the uppermost outer pin 27u.

  The upward opening 71 receives the splash of lubricating oil in the internal space L that is in an oil atmosphere. The splashes of the lubricating oil once accumulate on the bottom 72 b of the overhang member 72, and then go to the tank 74 through the communication oil passage 73. The lubricating oil that has reached the tank 74 flows down through a communication hole 75 formed at the bottom of the tank 74. In addition, since the cross-sectional area of the communication hole 75 is smaller than the opening cross-sectional area of the upward opening 71, the lubricating oil flow rate flowing down the communication hole 75 may be smaller than the lubricating oil flow rate passing through the upward opening 71. In this case, lubricating oil is stored in the tank 74.

  The lubricating oil in the tank 74 sequentially flows down the communication hole 75 and the through hole 45h, reaches the uppermost outer pin 27u, and includes a plurality of outer pins 27 arranged on the upper portion of the speed reduction portion B including the outer pin 27u. Encourage lubrication.

  According to the lubricating oil circuit of the present embodiment, the oil tank 53 that collects the lubricating oil inside the speed reduction part B, the oil pump 51 that sucks the lubricating oil from the oil tank 53 and discharges it to the speed reduction part side, and the motor casing A motor casing oil passage 55 provided on the cylindrical portion 22a and extending from the discharge port of the oil pump 51 to the motor rotation shaft 35, an axial oil passage 57 extending along the motor rotation shaft 35 and connected to the motor casing oil passage 55, and a rotor A rotor oil passage 59 that extends in the outer diameter direction from the axial oil passage 57 and injects lubricating oil into the inner space L of the motor casing cylindrical portion 22a, and an upward opening 71 provided on the inner wall surface of the pump casing 22p. The communication oil path 73 provided in the speed reduction part casing 22b is included. The communication oil passage 73 extends from the upward opening 71 toward the outer pin 27 u disposed above the speed reduction portion input shaft 25 among the plurality of outer pins 27. Since the lubricating oil injected from the rotor oil passage 59 is received by the upward opening 71 and supplied to the outer pin 27u via the communication oil passage 73, at the start of operation of the in-wheel motor drive device 21 or at low speed operation The lubricating oil can be supplied mainly from the internal space L of the motor part A to the outer pin 27 at the upper part of the speed reduction part B. Therefore, even when the rotation of the parts is slow inside the speed reduction part B and the stirring of the lubricating oil is weak inside the speed reduction part B, or even when the amount of axial center oil supply in the speed reduction part B is small, sufficient lubrication of the speed reduction part B Is secured.

  In particular, according to the present embodiment, since the outer peripheral surface of the end portion of each outer pin 27 is rotatably supported via the needle roller bearing 27a, a communication oil passage 73 is provided to lubricate the uppermost outer pin 27u. By supplying oil, the needle roller bearings 27a of the outer pins 27, including the uppermost outer pin 27u, are lubricated, and the friction loss of the speed reduction part B is reduced.

  Moreover, according to this embodiment, the motor casing cylindrical part 22a and the disk-shaped pump casing 22p which covers this edge part are included as a motor casing which makes the outline of the motor part A. The upper inner wall surface of the motor casing cylindrical portion 22a is formed on an inclined surface 22s that gradually increases in diameter from the central portion in the axial direction of the motor casing cylindrical portion 22a toward the end on the pump casing 22p side, as shown in FIG. The upward opening 71 is provided in the pump casing 22p. The curved wall surface 22r of the pump casing 22p spreads upward from the upward opening 71 and continues to the inclined surface 22s. As a result, the lubricant injected from the rotor 24 in the outer diameter direction scatters between the end portion of the stator 23 in the axis O direction and the pump casing 22p in the outer diameter direction, reaches the inclined surface 22s, and then the inclined surface 22s. To flow through the curved wall surface 22r to the upward opening 71. Therefore, the lubricating oil in the internal space L can be efficiently sent to the upward opening 71.

  Further, according to the present embodiment, the tank for storing the lubricating oil received by the upward opening 71 is provided in the middle of the oil passage from the upward opening 71 to the inside of the speed reduction unit B. Thereby, when the in-wheel motor drive device 21 repeats the low speed operation and the high speed operation, the lubricating oil received by the upward opening 71 can be continuously supplied to the outer pin 27u.

  Further, according to the present embodiment, the wheel hub 32 that includes the wheel hub 32 that is coupled to the speed reduction unit output shaft 28 is further provided, and the wheel hub bearing portion C that rotatably supports the wheel hub 32 is further provided. In the in-wheel motor drive device, the lubrication performance of the cycloid reducer can be improved.

  Further, according to the present embodiment, the speed reduction portion B is lubricated using the lubricating oil that has conventionally flowed from the internal space L to the oil tank 53. For this reason, even if compared with the conventional in-wheel motor drive device, there is no change in the amount of axial oil supply flowing into the motor unit and the speed reduction unit of the in-wheel motor drive device. There is no adverse effect such as insufficient lubrication on the components.

  Next, another embodiment of the present invention will be described. FIG. 8 is a partial vertical cross-sectional view showing a vehicle motor drive device according to another embodiment, and shows an encircled portion in FIG. 1 described above. FIG. 9 is a plan view showing an upward opening taken out from another embodiment. FIG. 10 is a front view showing an upward opening of another embodiment as viewed in the direction of the axis O. FIG. FIG. 11 is a cross-sectional view showing another embodiment of the upward opening cut along a plane perpendicular to the axis O. FIG. FIG. 12 is a cross-sectional view showing a communication passage of another embodiment cut along a plane perpendicular to the axis O. FIG. Regarding the other embodiments, the same reference numerals are given to the configurations common to the above-described embodiments, and the description thereof will be omitted, and different configurations will be described below. In another embodiment, as shown in the plan view of FIG. 9, a plurality of upward openings 71m and 71n are provided. The upward opening 71m is disposed at the center of the overhang member 72. The upward opening 71 n is disposed at the end of the overhang member 72.

  As shown in the cross-sectional view of FIG. 11, the upward opening 71m is disposed at a relatively high position, and the upward opening 71n is disposed at a relatively low position. A plurality of upward openings 71m, 71n are arranged in the circumferential direction around the axis O. The upward opening 71m is connected to the tank 74 via the communication oil passage 73 described above. Each upward opening 71 n is connected to one end of the communication oil passage 77. Each connecting oil passage 77 extends through the pump casing 22p, is further provided inside the wall thickness of the speed reduction portion casing 22b, and extends in the direction of the axis O. The other end portion of the communication oil passage 77 changes its direction and extends in the inner diameter direction, and is connected to the inside of the speed reduction portion casing 22b.

  A plurality of through holes 45 h are provided in the cylindrical portion of the outer pin holding member 45 at intervals in the circumferential direction. In the present embodiment, it is provided at a circumferential position facing the uppermost outer pin 27u and at a circumferential position facing the two outer pins 27v adjacent to the outer pin 27u. Of these three through holes 45h, the through holes 45h on both sides are aligned with the other end of the communication oil passage 77 in the radial direction as shown in FIG.

  The upward openings 71m and 71n receive the lubricant splash in the internal space L in the oil atmosphere, and the lubricant splash temporarily accumulates on the bottom 72b of the overhang member 72. Next, the lubricating oil sequentially flows from the upward opening 71m through the connecting oil passage 73, the tank 74, the connecting hole 75, and the through hole 45h, reaches the uppermost outer pin 27u, and includes the outer pin 27u and the speed reducing portion. A plurality of outer pins 27 arranged on the upper part of B are lubricated. Further, the lubricating oil sequentially flows from the upward opening 71n through the connecting oil passage 77 and the through hole 45h, reaches the upper outer pin 27v, and includes a plurality of outer pins arranged on the upper portion of the speed reduction portion B including the outer pin 27v. 27 is lubricated.

  According to such another embodiment, since a plurality of upward openings 71m, 71n are arranged in the circumferential direction around the axis O, a large number of upward openings can be arranged in the gap between the stator 23 and the pump casing 22p. A large amount of splashing of lubricating oil can be received in the internal space L in the oil atmosphere, and sufficient lubricating oil can be supplied to the outer pin 27.

  Next, still another embodiment of the present invention will be described. FIG. 13 is a longitudinal sectional view showing still another embodiment of the present invention. Further, regarding the other embodiments, the same reference numerals are given to configurations common to the above-described embodiments, description thereof is omitted, and different configurations will be described below. In still another embodiment, the two vehicle motor drive devices 20 are arranged coaxially and back to back. Each vehicle motor drive device 20 includes the motor part A and the speed reduction part B described above, and includes a drive shaft bearing part D instead of the wheel hub bearing part C described above. The motor part A, the reduction part B, and the drive shaft bearing part D are arranged coaxially and in series in this order.

  The pair of vehicle motor drive devices 20 are mounted on the vehicle body so as to be parallel to the vehicle width direction of the electric vehicle. At this time, each motor part A is arranged on the inner side in the vehicle width direction, and each drive shaft bearing part D is arranged on the outer side in the vehicle width direction. The drive shaft bearing portion D includes a cylindrical rotating member 81, rolling bearings 82 arranged in a double row, a sealing material 33 t, and a drive shaft 83.

  The front end of the speed reduction part output shaft 28 extending from the speed reduction part B to the outside in the vehicle width direction is inserted into the center hole of the rotation member 81, and the inner periphery of the rotation member 81 is splined to the outer periphery of the front end part of the speed reduction part output shaft 28. Or serrated. The rotating member 81 is inserted through a central hole formed at one end of the speed reduction portion casing 22b in the axis O direction. Double-row rolling bearings 82 are interposed in the annular space between the rotating member 81 and the speed reduction unit casing 22b. As a result, the rotating member 81 is rotatably supported by the speed reduction unit casing 22b via the rolling bearing 82. One end of the drive shaft 83 is attached and fixed to one end of the rotating member 81 in the axis O direction by a coupling tool such as a bolt 84. The other end (not shown) of the drive shaft 83 is coupled to the wheel hub via a constant velocity joint. Thereby, the drive shaft 83 drives the wheel attached to the wheel hub.

  Although the embodiments of the present invention have been described with reference to the drawings, the present invention is not limited to the illustrated embodiments. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

  The vehicle motor drive device according to the present invention is advantageously used in electric vehicles and hybrid vehicles.

20 vehicle motor drive device, 21 in-wheel motor drive device,
22 casing, 22a motor casing cylindrical part,
22p Pump casing (motor casing disk),
22b Deceleration portion casing, 22s inclined surface, 22r curved wall surface,
23 Stator, 24 Rotor, 25 Speed reducer input shaft,
25a, 25b Eccentric part, 26a, 26b Curved plate,
27, 27u, 27v outer pin (outer peripheral engagement member), 27a needle roller bearing,
28 Speed reducer output shaft, 30a, 30b through-hole, 31 inner pin,
32 wheel hub, 35 motor rotating shaft, 45 outer pin holding member,
45f inward flange, 45h through hole,
51 oil pump, 52 suction oil passage, 53 oil tank,
54 oil discharge passage, 55 motor casing oil passage,
57 axis oil passage, 59 rotor oil passage, 65 vertical hole,
66 discharge hole, 71, 71m, 71n upward opening,
72 overhang member, 72b bottom part, 72w wall part,
73 communication oil passage, 74 tanks, 75 communication holes,
76 through hole, 77 connecting oil passage, 81 rotating member,
83 Drive shaft, A motor part, B reduction part,
C wheel hub bearing part, D drive shaft bearing part,
L internal space, O axis, X axis of rotation.

Claims (6)

A motor unit, a deceleration unit that decelerates the rotation of the motor unit and outputs it to the wheel side, and a lubricating oil circuit that circulates lubricating oil through the deceleration unit,
The motor unit includes a motor rotating shaft, a rotor supported by the motor rotating shaft, a stator facing the rotor, and a motor casing that houses the rotor and the stator,
The speed reducer includes a speed reducer input shaft to which rotation is input from the motor rotation shaft,
An eccentric portion eccentrically coupled to the input shaft of the speed reducer;
The inner periphery has an inner periphery and an outer periphery, and the inner periphery is attached to the outer periphery of the eccentric portion so as to be relatively rotatable, and revolves around the axis of the speed reducer input shaft as the speed reducer input shaft rotates. Revolving members,
An outer periphery engaging member that engages with the outer periphery of the revolving member to cause the revolving motion of the revolving member;
A motion conversion mechanism that is provided near the inner periphery of the revolving member and extracts the revolving motion of the revolving member;
A speed reducer output shaft that outputs the rotation extracted by the motion conversion mechanism to the wheel side;
The eccentric portion, the revolution member, the outer peripheral engagement member, and the speed reduction portion casing that accommodates the motion conversion mechanism,
The lubricating oil circuit includes an oil tank that collects lubricating oil inside the speed reduction unit;
An oil pump that sucks lubricating oil from the oil tank and discharges the lubricating oil to the speed reduction unit side;
A motor casing oil passage provided in the motor casing and extending from a discharge port of the oil pump to the motor rotation shaft;
An axial oil passage extending along the motor rotation axis and connected to the motor casing oil passage;
A rotor oil passage that extends from the axial oil passage in an outer diameter direction and injects lubricating oil into the motor casing;
An upward opening that is provided on the inner wall surface of the motor casing and receives the lubricating oil injected from the rotor oil passage;
A vehicle motor drive device including a communication oil passage provided in the motor casing and extending from the upward opening toward an outer peripheral engagement member.   2. The vehicle motor drive device according to claim 1, wherein the outer peripheral engagement member is rotatably supported via a rolling bearing on an outer peripheral surface of an end of the outer peripheral engagement member. The motor casing includes a motor casing cylindrical portion and a motor casing disc portion covering an end portion of the motor casing cylindrical portion,
The upper inner wall surface of the motor casing cylindrical portion is formed on an inclined surface that gradually increases in diameter toward the end from the axial center of the motor casing cylindrical portion,
The upward opening is provided in the motor casing disc part,
3. The vehicle motor drive device according to claim 1, wherein an inner wall surface of the motor casing disk portion is continuously connected upward to the inclined surface from the upward opening.   4. The vehicle motor drive device according to claim 1, wherein the communication oil passage is connected to a tank that stores lubricating oil received by the upward opening. 5.   5. The vehicle motor drive device according to claim 1, wherein a plurality of the upward openings are arranged in a circumferential direction around the axis. 6.   The vehicle motor drive device according to any one of claims 1 to 5, further comprising a wheel hub bearing portion that includes a wheel hub coupled to the output shaft of the speed reduction unit and rotatably supports the wheel hub.

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