JP2018043682A - In-wheel motor drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly cool an upper part and a lower part of a stator of an electric motor with good efficiency.SOLUTION: An in-wheel motor drive device comprising a drive part which is configured from an electric motor, a deceleration part which decelerates and outputs rotation of the drive part, a bearing part which is configured from a wheel bearing, a casing for accommodating the electric motor, and a lubrication mechanism which supplies a lubrication oil to the drive part and cools the electric motor, in which a stator 23 of the electric motor is fixed to the casing. The lubrication mechanism comprises an oil passage which is provided at a stator upper site of the casing, an oil hole which is communicated with the oil passage and is opened above the stator 23, and a distribution plate 78 which is provided the oil hole and the stator 23, receives the lubrication oil flown down from the oil hole and supplies the same to an upper part and a lower part of the stator 23. An outlet port 85, which supplies the lubrication oil to the lower part of the stator 23, is provided at an end of the distribution plate 78 which is extended to a side part of the stator 23, and a division plate 87, which receives the lubrication oil flown down from the upper part of the stator 23 and discharges the same to the exterior of the stator 23, is provided on the side part of the stator 23.SELECTED DRAWING: Figure 4

Description

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

  A conventional in-wheel motor drive device has a structure disclosed in Patent Document 1, for example. The in-wheel motor drive device of Patent Document 1 includes an electric motor that drives a wheel, a speed reducer that decelerates the rotation of the electric motor, and a wheel bearing that is rotated by an output member that is coaxial with the input shaft of the speed reducer. It consists of and.

  The electric motor includes a stator fixed to the motor housing and a rotor attached to the motor rotation shaft. The stator has a structure in which a coil is wound around a stator core made of a magnetic material.

  The in-wheel motor drive device includes an oil supply mechanism that supplies lubricating oil to the electric motor and the speed reducer for the purpose of cooling the electric motor and lubricating the speed reducer.

  The oil supply mechanism of the electric motor and the reduction gear is a circulating structure that supplies the lubricating oil discharged from the built-in pump to the electric motor and the reducer with an axial oil supply structure that passes through the oil passage of the motor housing and returns to the built-in pump. It is said.

Japanese Patent Laid-Open No. 2006-86495

  By the way, the in-wheel motor driving device disclosed in Patent Document 1 requires an electric motor having a high speed rotation and a high torque while being small in size. When miniaturizing a high-speed rotation and high-torque electric motor, heat generation due to loss, particularly heat generation of a coil due to copper loss, becomes significant.

  In this in-wheel motor drive device, in order to cool the stator coil of the electric motor, an oil hole is provided in an oil passage disposed above the stator coil of the motor housing, and the lubricating oil pumped from the built-in pump is distributed to provide oil. The stator coil is supplied from the hole.

  However, in this oil supply mechanism, since the lubricating oil flows down from the upper part of the stator to the lower part, the temperature of the stator coil rises by absorbing the heat of the stator coil while the lubricating oil flows down from the upper part of the stator. End up.

  For this reason, the effect of cooling the lower portion of the stator is reduced by the temperature of the lubricating oil. As a result, there is a risk of uneven cooling at the upper and lower portions of the stator.

  Therefore, the present invention has been proposed in view of the above-described improvements, and the object of the present invention is to provide an in-wheel motor drive that enables uniform cooling at the upper and lower portions of the stator and efficiently cools the electric motor. To provide an apparatus.

  An in-wheel motor drive device according to the present invention accommodates a drive unit configured with an electric motor, a deceleration unit that decelerates and outputs rotation of the drive unit, a bearing unit configured with a wheel bearing, and a drive unit. And a lubricating mechanism for cooling the electric motor by supplying lubricating oil to the drive unit, and a structure in which the stator of the electric motor is fixed to the casing.

  The lubrication mechanism of the present invention includes an oil passage disposed in an upper portion of a stator of a casing, an oil hole communicating with the oil passage and opening above the stator, and an oil hole disposed between the oil hole and the stator. And a distribution plate that receives the lubricating oil flowing down from the stator and supplies it to the upper and lower portions of the stator.

  As technical means for achieving the above-mentioned object, the present invention provides an outlet for supplying lubricating oil to the lower part of the stator at the end where the distribution plate extends to the side of the stator. A partition plate that receives the lubricating oil flowing down from the upper portion of the stator and discharges it to the outside of the stator is disposed on the side portion.

  In the present invention, an outlet for supplying lubricating oil to the lower part of the stator is provided at the end of the distribution plate that extends to the side of the stator, so that new lubricating oil that has not increased in temperature is supplied to the lower part of the stator. Can be supplied to. In addition, a partition plate that receives the lubricating oil flowing down from the upper part of the stator and discharges it to the outside of the stator is disposed on the side of the stator, so that the lubricating oil whose temperature has increased by cooling the upper part of the stator is Can be avoided.

  In this way, the lubricating oil flowing down from the oil holes is supplied to the upper portion of the stator via the distribution plate, and the lubricating oil is supplied to the lower portion of the stator from the outlet of the distribution plate, so that the upper portion and the lower portion of the stator are uniform. The electric motor can be efficiently cooled.

  The partition plate according to the present invention includes a plate-like portion that is inserted between the coils of the stator, and a tongue piece that extends integrally from the plate-like portion and guides the lubricating oil received by the plate-like portion to the outside of the stator. A structure provided with a portion is desirable.

  By adopting such a structure, the lubricating oil received by the plate-like portion of the partition plate at the side of the stator can be led out of the stator by the tongue piece portion extending from the plate-like portion. As a result, the lubricating oil flowing down from the upper part of the stator can be reliably discharged, and the lubricating oil whose temperature has risen can be reliably avoided from flowing down to the lower part of the stator.

  In addition, the distribution plate in the present invention preferably has a structure in which a plurality of flow-down openings are provided corresponding to the coils located in the upper part of the stator.

  By adopting such a structure, when supplying the lubricating oil to the upper part of the stator, it is possible to reliably supply the lubricating oil to the coil located at the upper part of the stator from the downflow port.

  According to the present invention, by providing an outlet for supplying the lubricating oil to the lower part of the stator at the end where the distribution plate extends to the side of the stator, new lubricating oil that has not risen in temperature is supplied to the stator. Can be fed to the bottom of the. In addition, a partition plate that receives the lubricating oil flowing down from the upper part of the stator and discharges it to the outside of the stator is disposed on the side of the stator, so that the lubricating oil whose temperature has increased by cooling the upper part of the stator is Can be avoided.

  In this way, the lubricating oil flowing down from the oil holes is supplied to the upper portion of the stator via the distribution plate, and the lubricating oil is supplied to the lower portion of the stator from the outlet of the distribution plate, so that the upper portion and the lower portion of the stator are uniform. The electric motor can be efficiently cooled. As a result, it is easy to reduce the size of the electric motor by suppressing the heat generation of the stator.

In embodiment of this invention, it is sectional drawing which shows the whole structure of an in-wheel motor drive device. It is sectional drawing which follows the PP line | wire of FIG. It is a perspective view which shows the stator of the electric motor of FIG. It is sectional drawing which shows the distribution plate and partition plate of FIG. FIG. 4 is a partially enlarged perspective view showing a distribution plate and a partition plate in a portion X in FIG. 3. It is a partial expansion perspective view which shows the state which removed the partition plate of FIG. It is a top view which shows schematic structure of the electric vehicle carrying an in-wheel motor drive device. FIG. 8 is a rear sectional view showing the electric vehicle of FIG. 7.

  An embodiment of an in-wheel motor drive device according to the present invention will be described in detail with reference to the drawings. FIG. 7 is a schematic plan view of the electric vehicle 11 on which the in-wheel motor drive device 21 is mounted, and FIG. 8 is a schematic cross-sectional view of the electric vehicle 11 as viewed from the rear.

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

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

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

  The in-wheel motor drive device 21 of the embodiment shown in FIG. 1 has the following structure. Thereby, the compact in-wheel motor drive device 21 is implement | achieved and the electric vehicle 11 excellent in driving | running | working stability and NVH characteristic can be obtained by restraining unsprung weight.

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

  As shown in FIG. 1, the in-wheel motor drive device 21 includes a drive unit A that generates a driving force, a deceleration unit B that decelerates and outputs the rotation of the drive unit A, and an output from the deceleration unit B as driving wheels. As a rear wheel 14 (see FIGS. 7 and 8). The drive part A and the speed reduction part B are accommodated in the casing 22 and attached to the wheel housing 15 (see FIG. 8) of the electric vehicle 11.

  The drive unit A is a stator 23 fixed to the casing 22, a rotor 24 disposed so as to face the inner side in the radial direction of the stator 23 with a gap, and a rotor 24 disposed on the inner side in the radial direction of the rotor 24 so as to rotate integrally with the rotor 24. A radial gap type electric motor 26 having a motor rotating shaft 25 is provided. The drive unit A may be a motor other than the radial gap type, for example, an axial gap type electric motor.

  The motor rotating shaft 25 can rotate at a high speed of about 10,000 to 1000 rotations per minute. The stator 23 is configured by winding a coil 76 around a core 75 made of a magnetic material. The rotor 24 has a permanent magnet or a magnetic material disposed therein.

  The motor rotating shaft 25 holds the rotor 24 by a holder portion 27 that extends integrally outward in the radial direction. The holder portion 27 has a structure in which a concave groove into which the rotor 24 is fitted and fixed is formed in an annular shape. The motor rotating shaft 25 is rotatable with respect to the casing 22 by one end in the axial direction (right side in FIG. 1) on the rolling bearing 28 and the other end in the axial direction (left side in FIG. 1) by the rolling bearing 29. It is supported by.

  The reduction part B is composed of a parallel shaft gear reducer 39 including a first gear 30 as an input gear, second and third gears 31 and 32 as intermediate gears, and a fourth gear 33 as an output gear. ing. The speed reduction part B may be a speed reducer other than the parallel shaft gear speed reducer 39, for example, a planetary gear speed reducer or a cycloid speed reducer.

  In the parallel shaft gear reducer 39, the first gear 30 and the second gear 31 mesh with each other, and the third gear 32 and the fourth gear 33 mesh with each other, thereby reducing the rotational motion of the motor rotating shaft 25 in two stages. To do. For example, the reduction ratio at the first stage of the first gear 30 and the second gear 31 is 1 / 2.5, and the reduction ratio at the second stage of the third gear 32 and the fourth gear 33 is 1 / 4.5. In this case, the reduction ratio of the parallel shaft gear reducer 39 is about 1/11.

  Thus, when the parallel shaft gear reducer 39 having a large reduction ratio is used, the electric motor 26 can be reduced in size by combining with the high-speed electric motor 26 of about ten thousand rotations per minute. The in-wheel motor drive device 21 with a high reduction ratio can be realized.

  The first gear 30 is coaxially attached to the motor rotating shaft 25 by connecting a shaft portion 34 extending toward the inboard side to the motor rotating shaft 25 by spline fitting. The second gear 31 is attached to the intermediate shaft 35. The third gear 32 is formed integrally with the intermediate shaft 35. The fourth gear 33 is coaxially attached to the reduction gear output shaft 37 by connecting the shaft portion 36 to the inboard side shaft portion 38 of the reduction gear output shaft 37 by spline fitting.

  The shaft portion 34 of the first gear 30 is rotatably supported with respect to the casing 22 by a rolling bearing 40. The intermediate shaft 35 is rotatably supported with respect to the casing 22 by rolling bearings 41 and 42. The shaft portion 36 of the fourth gear 33 is rotatably supported with respect to the casing 22 by rolling bearings 43 and 44. Outboard side shaft portion 45 of reduction gear output shaft 37 is connected to hub wheel 47 of bearing portion C by spline fitting, and transmits the output of reduction portion B to rear wheel 14 (see FIGS. 7 and 8).

  The bearing portion C includes a wheel bearing 46 having the following structure. The wheel bearing 46 is disposed on the outer side of the hub wheel 47 and the inner ring 48, the hub wheel 47 connected to the reduction gear output shaft 37 so as to transmit torque, the inner ring 48 fitted to the outer periphery of the hub wheel 47. This is a double-row angular ball bearing that includes an outer ring 49, a plurality of balls 50 disposed between the hub ring 47 and the inner ring 48 and the outer ring 49, and a cage 51 that holds the plurality of balls 50. Seals 52 are provided at both end portions of the wheel bearing 46 in the axial direction to prevent entry of foreign matter and leakage of grease.

  The wheel bearing 46 is fastened to the parallel shaft gear reducer 39 by screwing a nut 53 into a male screw formed at the end of the outboard side shaft portion 45 of the reducer output shaft 37. In the wheel bearing 46, the outer ring 49 is fixed to the casing 22. The inner ring 48 is retained by coming into contact with the flange portion 54 of the reduction gear output shaft 37. The rear wheel 14 (see FIGS. 7 and 8) is connected to the hub wheel 47 by a hub bolt 55.

  The overall operation principle of the in-wheel motor drive device 21 having the above configuration will be described below.

  As shown in FIG. 1, in the drive unit A, the rotor 24 rotates by receiving an electromagnetic force generated by supplying an alternating current to the stator 23. In the speed reduction part B, the rotation of the motor rotation shaft 25 is decelerated by the first gear 30 to the fourth gear 33 of the parallel shaft gear speed reducer 39 and is transmitted to the bearing part C via the speed reducer output shaft 37.

  At this time, the rotation of the motor rotating shaft 25 is decelerated by the parallel shaft gear reducer 39 and transmitted to the reducer output shaft 37. Therefore, even when the low torque, high speed rotating electric motor 26 is employed, the rear wheel 14 It is possible to transmit the torque required for (see FIGS. 7 and 8).

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

  The in-wheel motor drive device 21 includes a lubrication mechanism that supplies lubricating oil to the electric motor 26 and the parallel shaft gear reducer 39 for the purpose of cooling the electric motor 26 and lubricating the parallel shaft gear reducer 39. As shown in FIG. 1, the lubrication mechanism includes a rotary pump 56, oil passages 57 and 58 provided in the casing 22, oil passages 59 to 63 provided in the motor rotation shaft 25, and the first gear 30. And the oil path 64,65 arrange | positioned at the axial part 34 is made into the main structure.

  The rotary pump 56 includes a pump drive shaft 66 that is coaxially connected to the inboard side end portion of the intermediate shaft 35, and is incorporated in the casing 22 by a presser plate 67. The pump drive shaft 66 is rotatably supported by the rolling bearing 41 with respect to the casing 22. A discharge port 68 and a suction port 69 of the rotary pump 56 are provided in the casing 22. In addition, the partition wall 70 of the casing 22 that divides the drive unit A and the speed reduction unit B is provided with an oil drain hole 71 (see FIG. 2) through which the lubricating oil flows from the drive unit A to the speed reduction unit B.

  An oil passage 57 extending from the discharge port 68 of the rotary pump 56 circulates inside the casing 22 and communicates with the oil passage 59 at the end of the motor rotating shaft 25 on the inboard side. The oil passage 59 communicates with an oil passage 60 extending toward the rotor 24 on the lubricating oil inflow side of the motor rotating shaft 25. The oil passage 60 communicates with an oil passage 61 extending in the axial direction while contacting the inner periphery of the rotor 24 at the end thereof. The oil passage 61 communicates with an oil passage 62 that extends toward the axial center at the end thereof. The oil passage 62 communicates with the oil passage 63 on the lubricating oil outflow side of the motor rotating shaft 25. The oil passage 63 communicates with the oil passage 64 of the shaft portion 34 of the first gear 30 at the outboard side end portion of the motor rotation shaft 25.

  An oil passage 64 extending along the axial direction inside the shaft portion 34 of the first gear 30 communicates with an oil passage 65 extending along the radial direction inside the first gear 30. The oil passage 64 opens at the end portion on the outboard side of the first gear 30. The oil passage 65 opens at the tooth surface of the first gear 30.

  One end of the oil passage 58 for returning the lubricating oil to the rotary pump 56 communicates with the suction port 69 of the rotary pump 56, and the other end opens to the speed reduction part B side below the partition wall 70 of the casing 22. The rotary pump 56 for forcibly circulating the lubricating oil is provided between an oil passage 57 that communicates with the discharge port 68 and an oil passage 58 that communicates with the suction port 69.

  As shown in FIGS. 1 and 2, the rotary pump 56 includes an inner rotor 72 attached to the inboard side end of the pump drive shaft 66, an outer rotor 73 rotatably supported by the casing 22, a pump chamber 74, and the like. The cycloid pump includes a discharge port 68 communicating with the oil passage 57 and a suction port 69 communicating with the oil passage 58. Since the rotary pump 56 is driven by the rotation of the intermediate shaft 35, a separate drive mechanism is not required, so that the number of parts can be reduced.

  The inner rotor 72 rotates in synchronization with the rotation of the intermediate shaft 35 by being driven by decelerating the rotation of the motor rotation shaft 25 in the first stage composed of the first gear 30 and the second gear 31. On the other hand, the outer rotor 73 is driven to rotate as the inner rotor 72 rotates. By disposing the rotary pump 56 in the casing 22, it is possible to prevent the in-wheel motor drive device 21 from becoming large.

  The inner rotor 72 rotates about the rotation center C1, and the outer rotor 73 rotates about the rotation center C2. Since the inner rotor 72 and the outer rotor 73 rotate about different rotation centers C1 and C2, the volume of the pump chamber 74 changes continuously. As a result, the lubricating oil flowing from the suction port 69 is pumped from the discharge port 68 to the oil passage 57.

  The flow of the lubricating oil by the lubricating mechanism will be described below. In FIG. 1, the white arrow attached to the inside of the oil passage of the in-hole motor drive device 21 indicates the flow of the lubricating oil. Although not shown, lubricating oil is stored in the lower part of the casing 22 in the drive part A and the speed reduction part B.

  In the drive unit A, the rotor 24 of the electric motor 26 is cooled as follows.

  The lubricating oil pumped from the discharge port 68 of the rotary pump 56 reaches the oil path 59 of the motor rotating shaft 25 via the oil path 57. In the motor rotating shaft 25, the lubricating oil reaches the oil path 61 from the oil path 60 with the centrifugal force and pump pressure accompanying the rotation, and the rotor 24 of the electric motor 26 is cooled by the lubricating oil flowing through the oil path 61. The lubricating oil that has cooled the rotor 24 reaches the oil passage 63 through the oil passage 62, and travels to the oil passage 64 of the shaft portion 34 of the first gear 30.

  In cooling the rotor 24 of the electric motor 26, the lubricating mechanism is configured by the oil passages 60 and 62 on the lubricating oil inflow side and the lubricating oil outflow side and the oil passage 61 in contact with the inner periphery of the rotor 24 of the electric motor 26. The rotor 24 of the electric motor 26 can be cooled with the lubricating oil flowing through the oil passage 61.

  In the drive unit A, the stator 23 of the electric motor 26 is cooled as follows.

  The lubrication mechanism for cooling the stator 23 has the following structure. As shown in FIG. 1, in an oil passage 57 disposed in the upper part of the casing 22, the portion of the stator 23 where the core 75 is attached communicates with the oil passage 57 and opens at a position above the coil 76 of the stator 23. An oil hole 77 is provided. Between the oil hole 77 and the coil 76, a bowl-shaped distribution plate 78 that receives the lubricating oil flowing down from the oil hole 77 is disposed. In this embodiment, the distribution plate 78 is attached to the side surface of the core 75, but it is also possible to attach it to other fixed parts such as the casing 22.

  As shown in FIGS. 3 and 4, the distribution plate 78 has a concave cross section composed of a vertically arranged side plate portion 79 and a horizontally arranged bottom plate portion 80. Since the plurality of coils 76 are arranged along the circumferential direction of the annular core 75, the distribution plate 78 has a semicircular arc shape along the arrangement direction of the coils 76. A top plate portion 81 is provided at both ends of the distribution plate 78. A portion excluding the top plate portion 81 opens upward. The lubricating oil flowing down from the oil holes 77 (see FIG. 1) is supplied to the bottom plate portion 80 through the openings 82 of the distribution plate 78.

  The bottom plate portion 80 of the distribution plate 78 is provided with a plurality of (four in the figure) flow-down ports 83 corresponding to the coils 76 positioned on the top of the stator 23. A tongue-shaped oil guide piece 84 extending downward toward the coil 76 is extended at the flow-down port 83. In this embodiment, the oil guiding piece 84 is provided on the upstream side where the lubricating oil flows down, but the oil guiding piece may be provided on the downstream side where the lubricating oil flows down.

  Further, both end portions of the distribution plate 78 extend to the coil 76 located on the side portion of the stator 23, and an outlet 85 is provided in the bottom plate portion 80 at both end portions. A tongue-shaped oil guide piece 86 extending inward in the lateral direction toward the coil 76 is also extended to the outflow port 85.

  On the other hand, in the vicinity of the coil 76 located on the side of the stator 23, that is, in the vicinity of both ends of the distribution plate 78, the lubricating oil flowing down from the coil 76 located on the top of the stator 23 is received and discharged to the outside of the stator 23. A partition plate 87 is provided. 5 is an enlarged view of a portion X in FIG. 3, and FIG. 6 is a view showing a state in which the partition plate 87 in FIG. 5 is removed.

  As shown in the figure, the partition plate 87 includes a plate-like portion 88 inserted and disposed between the coils 76 of the stator 23, and the lubrication that is integrally extended from the plate-like portion 88 and received by the plate-like portion 88. And a tongue piece 89 that guides oil to the outside of the stator 23. The plate-shaped part 88 is horizontally arranged, and the tongue piece part 89 is bent downward. An oil guide portion 90 that is bent upward is provided on the tongue piece 89 side of the plate-like portion 88.

  The plate-like portion 88 of the partition plate 87 is disposed above the outlet 85 of the distribution plate 78 so that the lubricating oil discharged from the outlet 85 of the distribution plate 78 can be supplied to the lower portion of the stator 23. (See FIG. 4). The partition plate 87 is fixed by attaching the plate-shaped portion 88 to the core 75 or the coil 76 by an appropriate means.

  In this lubricating mechanism, the lubricating oil flowing through the oil passage 57 of the casing 22 flows down from the oil hole 77 (see FIG. 1) to the bottom plate portion 80 of the distribution plate 78. In FIG. 4, the flow of the lubricating oil is indicated by arrows. Lubricating oil (see arrow A in FIG. 4) that has flowed down to the bottom plate portion 80 of the distribution plate 78 is diverted to each flow-down port 83 of the bottom plate portion 80 and guided to the oil guide piece 84 from the flow-down port 83 while being stator 23. It flows down to the coil 76 located in the upper part of. The coil 76 positioned above the stator 23 is cooled by the lubricating oil (see arrow B in FIG. 4) supplied from the flow down port 83 while being guided by the oil guide piece 84.

  Here, the lubricating oil that has cooled the coil 76 positioned on the upper portion of the stator 23 is received by the plate-like portion 88 of the partition plate 87 and discharged from the tongue piece portion 89 to the outside of the stator 23 while being guided by the oil guide portion 90. (See arrow C in FIG. 4).

  As described above, the coil 76 positioned on the side of the stator 23 is provided with the partition plate 87 that receives the lubricating oil flowing down from the coil 76 positioned above the stator 23 and discharges it to the outside of the stator 23. It is possible to avoid the lubricating oil whose temperature has been increased by cooling the coil 76 located at the upper part of the flow 23 from flowing down to the coil 76 located at the lower part of the stator 23.

  Further, the lubricating oil (see arrow D in FIG. 4) that has flowed down to the bottom plate portion 80 of the distribution plate 78 and moved to both ends thereof is positioned below the stator 23 while being guided from the outlet 85 to the oil guide piece 86. It flows down to the coil 76. The coil 76 positioned below the stator 23 is cooled by the lubricating oil (see arrow E in FIG. 4) supplied from the outlet 85 while being guided by the oil guide piece 86.

  Thus, by providing the outlet 85 which supplies lubricating oil to the coil 76 located in the lower part of the stator 23 at both ends of the distribution plate 78 extended to the coil 76 located on the side part of the stator 23. The new lubricating oil whose temperature has not risen can be supplied to the coil 76 located under the stator 23.

  As described above, the lubricating oil flowing down from the oil hole 77 (see FIG. 1) of the oil passage 57 is supplied to the coil 76 positioned above the stator 23 via the distribution plate 78 and the outlet 85 of the distribution plate 78. Is supplied to the coil 76 positioned below the stator 23, the coil 76 positioned above the stator 23 and the coil 76 positioned below the stator 23 can be cooled uniformly, and the electric motor 26. Can be efficiently cooled. As a result, since the heat generation of the coil 76 can be suppressed, the electric motor 26 can be easily downsized.

  On the other hand, as shown in FIG. 1, as the lubrication of the speed reduction unit B, the lubricating oil in the oil passage 63 is fed through the oil passages 64 and 65 by the centrifugal force and the pump pressure accompanying the rotation of the motor rotating shaft 25 to the first gear. The first gear 30 that flows out to the tooth surface 30 and rotates at high speed is lubricated. The first-stage second gear 31 and the second-stage third gear 32 and the fourth gear 33 are lubricated by splashing the lubricating oil stored in the lower part of the casing 22 in the speed reduction portion B.

  The lubricating oil that has cooled the drive unit A and lubricated the speed reduction unit B travels down the inner wall surface of the casing 22 due to gravity. The lubricating oil that has moved to the lower part of the drive part A flows into the lower part of the speed reducing part B from the oil drain hole 71 (see FIG. 3). The lubricating oil that has moved to and entered the lower portion of the speed reduction unit B is sucked up from the oil passage 58 of the casing 22 and returns to the suction port 69 of the rotary pump 56.

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

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

DESCRIPTION OF SYMBOLS 21 In-wheel motor drive device 22 Casing 23 Stator 26 Electric motor 46 Wheel bearing 57 Oil path 76 Coil 77 Oil hole 78 Distribution plate 83 Downflow outlet 85 Outlet 87 Partition plate 88 Plate-shaped part 89 Tongue piece part A Drive part B Deceleration Part C Bearing part

Claims (3)

A drive unit configured by an electric motor, a deceleration unit that decelerates and outputs the rotation of the drive unit, a bearing unit configured by a wheel bearing, a casing that houses the drive unit, and lubricating oil for the drive unit An in-wheel motor drive device comprising a lubrication mechanism for supplying and cooling the electric motor, wherein the stator of the electric motor is fixed to the casing,
The lubrication mechanism includes an oil passage disposed in an upper portion of the stator of the casing, an oil hole communicating with the oil passage and opening above the stator, and disposed between the oil hole and the stator and flowing down from the oil hole. A distribution plate that receives the lubricated oil and supplies it to the upper and lower portions of the stator,
An outlet for supplying lubricating oil to the lower portion of the stator is provided at an end portion where the distribution plate extends to the side portion of the stator, and the lubricating oil flowing down from the upper portion of the stator is received on the side portion of the stator. An in-wheel motor drive device comprising a partition plate for discharging to the outside of the stator.   The partition plate includes a plate-like portion that is inserted between the coils of the stator, and a tongue piece portion that extends integrally from the plate-like portion and guides the lubricating oil received by the plate-like portion to the outside of the stator. The in-wheel motor drive device of Claim 1 provided with.   3. The in-wheel motor drive device according to claim 1, wherein the distribution plate is provided with a plurality of flow-down openings corresponding to coils located on an upper portion of the stator.

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