JP5687839B2 - In-wheel motor drive device - Google Patents

Description

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

  A conventional in-wheel motor drive device 101 is described in, for example, Japanese Patent Application Laid-Open No. 2009-63043 (Patent Document 1).

  As shown in FIG. 10, the in-wheel motor driving device 101 includes a motor unit 103 that generates a driving force inside a housing 102 that is attached to a vehicle body, a wheel hub bearing unit 104 that is connected to a wheel, and a motor unit 103. And a speed reduction part 105 that decelerates the rotation of the motor and transmits it to the wheel hub bearing part 104.

  In the in-wheel motor drive device 101 having the above configuration, a low torque and high rotation motor is employed for the motor unit 103 from the viewpoint of making the device compact. On the other hand, the wheel hub bearing portion 104 requires a large torque to drive the wheel. For this reason, a cycloid reducer that is compact and provides a high reduction ratio is often used for the reduction unit 105.

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

JP 2009-63043 A

  The in-wheel motor drive device 101 configured as described above includes a speed reduction unit lubrication mechanism that supplies lubricating oil to the speed reduction unit 105.

  The speed reducer lubrication mechanism includes a lubricating oil passage 112 a provided in the motor-side rotating member 112, a lubricating oil supply port 112 b extending from the lubricating oil passage 112 a toward the outer diameter surface of the motor-side rotating member 112, and the housing 102. The lubricating oil discharge port 102b that discharges the lubricating oil from the speed reduction unit 105, connects the lubricating oil discharge port 102b, and the lubricating oil passage 112a, and connects the lubricating oil discharged from the lubricating oil discharge port 102b to the lubricating oil passage 102a. A circulating oil passage 102c that recirculates to the inside, and a rotary pump 113 that is disposed in the housing 102 and circulates the lubricating oil using the rotation of the wheel-side rotating member 110.

  Between the lubricating oil discharge port 102 b and the rotary pump 113, a lubricating oil storage portion 102 d that temporarily stores lubricating oil is provided below the speed reduction portion housing 102 e of the speed reduction portion 105.

  As described above, the oil passage for circulating the lubricating oil is provided, and the lubricating oil is forcibly circulated by the rotary pump 113, so that the lubricating oil can be stably supplied to the entire speed reduction unit 105, and the stirring is performed. An increase in resistance can be prevented.

  By the way, as a problem of the in-wheel motor drive device 101, it is necessary to make the axial dimension as small as possible in order to secure a wide interior space.

  In order to reduce the axial dimension, it is necessary to flatten the reduction part 105 and the motor part 103 in the radial direction, but the in-wheel motor drive device 101 is a small vehicle such as a minicar or a muter. When applied to a car, since the size of the wheel 114 is reduced, there is a natural limit to expanding the speed reduction unit 105 and the motor unit 103 in the radial direction.

  In addition, there is a space limitation around the speed reduction unit 105 due to attachment of a brake, a hub, a suspension device, and the like.

  Therefore, when the lubricating oil storage part 102d is arranged below the speed reduction part housing 102e as in the conventional example, the following problem occurs.

  Since the volume that can be secured between the speed reduction unit housing 102e and the wheel 114 is small, the volume of the lubricating oil reservoir 102d is also small, and the amount of oil is insufficient.

  If this shortage of oil is solved by adding oil so that the speed reduction unit 105 and the motor unit 103 are immersed, the stirring loss increases, and thus the problem of inefficiency of the in-wheel motor drive device 101 occurs.

  Moreover, even if the lubricating oil reservoir 102d is disposed below the speed reduction housing 102e and a sufficient amount of oil can be secured, the gap between the lubricating oil reservoir 102d and the wheel 114 is narrow, and the wheel 114 There was also a problem that the air cooling effect was small when placed inside.

  Therefore, the present invention can ensure a large lubricating oil reservoir within a range that does not hinder travel, and further improves the air cooling effect of the lubricating oil reservoir, and the recovery path for the lubricating oil circulated to the speed reducer is short. Therefore, an in-wheel motor drive device capable of smoothly collecting the lubricating oil is provided.

In order to solve the above-described problems, the present invention provides a motor unit that rotationally drives the motor-side rotating member (25) and a wheel-side rotating member (28) that decelerates the rotation of the motor-side rotating member (25). A speed reducing portion that transmits, a housing (22) that holds the motor portion and the speed reducing portion, a wheel hub fixedly connected to the wheel side rotating member (28), and a speed reducing portion that supplies lubricating oil to the speed reducing portion And a reduction mechanism lubrication mechanism including a lubricating oil passage (25c) provided inside the motor-side rotation member (25), and the motor-side rotation member (25) from the lubricating oil passage (25c). A lubricating oil supply port (25d) extending toward the outer diameter surface, a lubricating oil discharge port (22b) for discharging lubricating oil from a housing (22f) holding the speed reduction portion, and the lubricating oil discharge port (22b) And the lubricating oil passage (2 c) and a circulating oil passage (22e) for returning the lubricating oil discharged from the lubricating oil discharge port (22b) to the lubricating oil passage (25c), and the housing (22). An in-wheel motor drive device comprising: a rotary pump (51) that circulates lubricating oil using rotation of the wheel-side rotating member (28);
A lubricating oil reservoir (22d) is provided below the outer diameter of the motor part of the housing (22g) that holds the outer diameter of the motor part, and the outer diameter of the motor part that partitions the lubricating oil reservoir (22d) is set. The holding housing (22g) is provided with a lubricating oil discharge port (22c) for communicating the inside of the motor portion and the lubricating oil storage portion (22d), and at least one location of the housing (22f) holding the outer diameter of the speed reducing portion Provided with a lubricating oil discharge port (22b) that communicates the inside of the lower part of the speed reduction part and the inside of the lower part of the motor part, and is lower than the outer diameter of the motor part of the housing (22g) that holds the outer diameter of the motor part. The lubricating oil stored in the lubricating oil storage section (22d) on the side is returned to the lubricating oil passage (25c) through the circulating oil passage (22e) by the rotary pump (51).

  A part of the lubricating oil storage part may extend to a lower part of a housing that holds the speed reduction part.

  It is preferable to provide fins for air cooling on the outer surface of the lubricating oil reservoir.

  When the lubricating oil reservoir is made of a casting, the air-cooling fin can be formed integrally with the lubricating oil reservoir.

  Further, the lubricating oil storage part and the housing for holding the motor part can be integrated.

  A cycloid pump can be used as the rotary pump.

  The rotary pump may be driven at a rotational speed after deceleration instead of the rotational speed of the motor unit.

  The pipe that sucks up the lubricating oil from the lubricating oil reservoir may be fixed to the motor housing by screwing and press fitting, or may be formed integrally with the motor housing.

  It is desirable that the pipe and the drain hole for sucking up the lubricating oil from the lubricating oil reservoir are arranged coaxially in manufacturing.

  In the in-wheel motor drive device according to the present invention, as described above, the lubricating oil reservoir that temporarily stores the lubricating oil between the lubricating oil discharge port and the rotary pump is provided in the lower portion of the housing that holds the motor unit. As a result, it is possible to secure a large lubricating oil reservoir in a range where there is no hindrance to driving, and the air cooling effect of the lubricating oil reservoir is improved, and the recovery route for the lubricating oil circulated to the speed reduction unit is short and lubricates. Smooth oil recovery is possible.

It is a schematic sectional drawing of the in-wheel motor drive device concerning one Embodiment of this invention. It is an enlarged view of the motor part of FIG. It is an enlarged view of the deceleration part of FIG. It is an enlarged view of the wheel hub bearing part of FIG. It is sectional drawing of the VV line of FIG. It is an enlarged view of the eccentric part periphery of FIG. It is the figure which looked at the rotary pump of FIG. 1 from the axial direction. It is a schematic plan view of the electric vehicle which has the in-wheel motor drive device of FIG. It is the figure seen from the vehicle back of FIG. It is a schematic sectional drawing of the conventional in-wheel motor drive device.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
As shown in FIG. 8, an electric vehicle 11 having an in-wheel motor drive device according to an embodiment of the present invention includes a chassis 12, a front wheel 13 as a steering wheel, a rear wheel 14 as a drive wheel, And an in-wheel motor drive device 21 that transmits a driving force to each of the rear wheels 14. As shown in FIG. 9, the rear wheel 14 is housed inside a wheel housing 12a of the chassis 12, and is fixed to the lower portion of the chassis 12 via a suspension device (suspension) 12b.

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

  The electric vehicle 11 needs to be provided with a motor, a drive shaft, a differential gear mechanism, and the like on the chassis 12 by providing an in-wheel motor drive device 21 for driving the left and right rear wheels 14 inside the wheel housing 12a. This eliminates the need to secure a wide cabin space and control the rotation of the left and right drive wheels.

On the other hand, in order to improve the running stability of the electric vehicle 11, it is necessary to suppress the unsprung weight. In addition, in-wheel motor drive device 21 is required to be downsized in order to secure a wider cabin space. Therefore, an in-wheel motor drive device 21 according to an embodiment of the present invention as shown in FIG. 1 is employed.
First, as shown in FIG. 1, the in-wheel motor drive device 21 includes a motor unit A that generates a driving force, a deceleration unit B that decelerates and outputs the rotation of the motor unit A, and an output from the deceleration unit B. A wheel hub bearing portion C for transmitting to the drive wheel 14 is provided, and the motor portion A and the speed reduction portion B are housed in the housing 22 and are mounted in the wheel housing 12a of the electric vehicle 11 as shown in FIG.

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

  The motor side rotation member 25 is arranged from the motor part A to the speed reduction part B in order to transmit the driving force of the motor part A to the speed reduction part B, and has eccentric parts 25a and 25b in the speed reduction part B. One end of the motor-side rotating member 25 is fitted to the rotor 24 and is supported by the rolling bearing 36 c in the speed reduction portion B. Further, the two eccentric portions 25a and 25b are provided with a 180 ° phase change in order to cancel out the centrifugal force due to the eccentric motion.

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

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

  As shown in FIG. 5, the curved plates 26a and 26b have a plurality of corrugated waves composed of trochoidal curves such as epitrochoids on the outer periphery, and a plurality of through holes 30a penetrating from one end face to the other end face. Have A plurality of through holes 30a are provided at equal intervals on the circumference centering on the rotation axis of the curved plates 26a, 26b, and receive inner pins 31 described later. Further, the through hole 30b is provided at the center of the curved plates 26a and 26b and is fitted to the eccentric portions 25a and 25b.

  The curved plate 26a is rotatably supported by the rolling bearing 41 with respect to the eccentric portion 25a. As shown in FIG. 6, the rolling bearing 41 is fitted to the outer diameter surface of the eccentric portion 25a, the inner ring member 42 having an inner raceway surface 42a on the outer diameter surface, and the inner diameter of the through hole 30b of the curved plate 26a. The outer raceway surface 43 formed directly on the surface, a plurality of cylindrical rollers 44 disposed between the inner raceway surface 42a and the outer raceway surface 43, and a retainer (not shown) that keeps an interval between the adjacent cylindrical rollers 44 It is a cylindrical roller bearing provided with.

  The outer pins 27 are provided at equal intervals on a circumferential track centering on the rotation axis of the motor side rotation member 25. When the curved plates 26a and 26b revolve, the curved waveform and the outer pin 27 engage with each other to cause the curved plates 26a and 26b to rotate. Further, in order to reduce the frictional resistance with the curved plates 26a, 26b, needle roller bearings 27a are provided at positions where they abut against the outer peripheral surfaces of the curved plates 26a, 26b.

  The counterweight 29 has a disc shape and has a through-hole that fits with the motor-side rotation member 25 at a position off the center, in order to cancel out the unbalanced inertia couple caused by the rotation of the curved plates 26a and 26b. It is arranged at a position adjacent to each eccentric part 25a, 25b with a 180 ° phase change from the eccentric part.

  Here, as shown in FIG. 6, when the center point between the two curved plates 26a and 26b is G, the distance between the central point G and the center of the curved plate 26a is the right side of the central point G in FIG. L1, the sum of the mass of the curved plate 26a, the rolling bearing 41, and the eccentric portion 25a is m1, the amount of eccentricity of the center of gravity of the curved plate 26a from the rotational axis is ε1, and the distance between the center point G and the counterweight 29 is L2. Assuming that the mass of the counterweight 29 is m2 and the amount of eccentricity from the rotational axis of the center of gravity of the counterweight 29 is ε2, the relationship satisfies L1 × m1 × ε1 = L2 × m2 × ε2. A similar relationship is also established between the curved plate 26b on the left side of the center point G in FIG.

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

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

  The speed reduction unit lubrication mechanism supplies lubricating oil to the speed reduction unit B, and includes a lubricating oil passage 25c, a lubricating oil supply port 25d, lubricating oil discharge ports 22b and 22c, a lubricating oil storage unit 22d, and a rotation. A pump 51 and a circulating oil passage 22e are provided.

  The lubricating oil passage 25c extends along the axial direction inside the motor-side rotating member 25. The lubricating oil supply port 25d extends from the lubricating oil passage 25c toward the outer diameter surface of the motor-side rotating member 25. In this embodiment, the lubricating oil supply port 25d is provided in the eccentric portions 25a and 25b.

  In addition, a lubricating oil discharge port 22b that discharges the lubricating oil inside the speed reducing portion B is provided at at least one position below the housing 22f that holds the speed reducing portion B. The lubricating oil discharge port 22b is connected to the lower portion of the housing 22g that holds the motor portion A, and communicates with the lubricating oil storage portion 22d provided at the lower portion of the housing 22g via the lubricating oil discharge port 22c.

  The lubricating oil reservoir 22d is provided with a pipe 61 for sucking up the lubricating oil, and the lubricating oil in the lubricating oil reservoir 22d is sucked up by the rotary pump 51 and forced to the lubricating oil passage 25c via the circulating oil passage 22e. Reflux.

  Here, as shown in FIG. 7, the rotary pump 51 includes an inner rotor 52 that rotates using the rotation of the wheel-side rotating member 28, an outer rotor 53 that rotates following the rotation of the inner rotor 52, and a pump The cycloid pump includes a chamber 54, a suction port 55 communicating with the pipe 61, and a discharge port 56 communicating with the circulating oil passage 22c.

  Inner rotor 52 has a tooth profile formed of a cycloid curve on the outer diameter surface. Specifically, the shape of the tooth tip portion 52a is an epicycloid curve, and the shape of the tooth gap portion 52b is a hypocycloid curve. The inner rotor 52 is fitted to the outer diameter surface of the cylindrical portion 31d of the stabilizer 31b and rotates integrally with the inner pin 31 (wheel-side rotating member 28).

  The outer rotor 53 has a tooth profile constituted by a cycloid curve on the inner diameter surface. Specifically, the shape of the tooth tip portion 53a is a hypocycloid curve, and the shape of the tooth gap portion 53b is an epicycloid curve. The outer rotor 53 is rotatably supported by the housing 22.

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

  A plurality of pump chambers 54 are provided in the space between the inner rotor 52 and the outer rotor 53. When the inner rotor 52 rotates using the rotation of the wheel side rotation member 28, the outer rotor 53 rotates in a driven manner. At this time, since the inner rotor 52 and the outer rotor 53 rotate about different rotation centers c1 and c2, respectively, the volume of the pump chamber 54 changes continuously. As a result, the lubricating oil flowing in from the suction port 55 is pumped from the discharge port 56 to the circulation flow path 22e.

  Furthermore, between the lubricating oil discharge port 22b and the rotary pump 51, there is provided a lubricating oil reservoir 22d that temporarily stores the lubricating oil.

  The lubricating oil reservoir 22d is provided in the lower part of the housing 22g that holds the motor part A.

  In the embodiment of FIG. 1, the lubricating oil reservoir 22d is provided in the lower part of the housing 22g that holds the motor part A. However, a part of the lubricating oil reservoir 22d extends toward the housing 22f of the speed reduction part B. May be provided.

  This lubricating oil storage part 22d can be formed by casting integrally with the housing 22g holding the motor part A.

  In addition, air cooling fins 64 are integrally formed on the outer surface of the lubricating oil reservoir 22d.

  The pipe 61 that sucks up the lubricating oil from the lubricating oil reservoir 22d by the rotary pump 51 may be fixed to the housing 22g of the motor part A by screwing and press fitting, or may be formed integrally with the housing of the motor part. .

  A drain hole 63 is provided below the lubricating oil reservoir 22d. The drain hole 63 is normally closed by a bolt 63. The drain hole 63 is preferably arranged on the same axis as the pipe 61 for manufacturing.

  Note that the rotary pump 51 may be driven not at the rotational speed of the motor unit A but at the rotational speed after deceleration.

  As described above, when the lubricating oil reservoir 22d is provided, the lubricating oil that cannot be discharged by the rotary pump 51 can be temporarily stored in the lubricating oil reservoir 22d during high-speed rotation. As a result, an increase in torque loss of the deceleration unit B can be prevented. On the other hand, at the time of low speed rotation, the lubricating oil stored in the lubricating oil reservoir 22d can be returned to the lubricating oil passage 25c even if the amount of lubricating oil reaching the lubricating oil discharge port 22b decreases. As a result, the lubricating oil can be stably supplied to the deceleration unit B.

  The flow of the lubricating oil in the deceleration portion B having the above configuration will be described. First, the lubricating oil flowing through the lubricating oil passage 25 c flows out from the opening 42 b penetrating the lubricating oil supply port 25 d and the inner ring member 42 to the speed reduction unit B due to the centrifugal force accompanying the rotation of the motor-side rotating member 25.

  Since centrifugal force further acts on the lubricating oil inside the speed reduction portion B, the inner raceway surface 42a, the outer raceway surface 43, the contact portions between the curved plates 26a, 26b and the inner pin 31, and the curved plates 26a, 26b and the outer It moves outward in the radial direction while lubricating the contact portion with the pin 27 and the like.

  The lubricating oil that has reached the inner wall surface of the housing 22 is discharged from the lubricating oil discharge ports 22b and 22c and stored in the lubricating oil storage portion 22d. The lubricating oil stored in the lubricating oil storage part 22d is sucked up by the rotary pump 51 through the pipe 61, is pumped from the discharge port 56 to the circulating oil path 22e, and passes through the circulating oil path 22e to the lubricating oil path 25c. Reflux.

  Here, the amount of lubricating oil discharged from the lubricating oil discharge port 22 b increases in proportion to the rotational speed of the motor-side rotating member 25. On the other hand, since the inner rotor 52 rotates integrally with the wheel side rotation member 28, the discharge amount of the rotary pump 51 increases in proportion to the rotation speed of the wheel side rotation member 28. In addition, the amount of lubricating oil supplied from the lubricating oil discharge port 22 b to the speed reduction unit B increases in proportion to the discharged amount of the rotary pump 51. That is, since the supply amount and the discharge amount of the lubricating oil to the speed reduction unit B both change with the rotation speed of the in-wheel motor drive device 21, the lubricating oil can always be circulated smoothly.

  Further, a part of the lubricating oil flowing through the circulating oil passage 22e reaches the speed reduction part B from between the housing 22 and the motor side rotation member 25 through the rolling bearing 36a, the motor part A, and the rolling bearing 36b. The lubricating oil flowing in this path lubricates the rolling bearings 36a and 36b and also functions as a coolant for cooling the motor part A.

  In this way, by supplying the lubricating oil from the motor side rotating member 25 to the speed reduction unit B, the shortage of the lubricating oil amount around the motor side rotating member 25 can be solved. Further, by forcibly discharging the lubricating oil by the rotary pump 51, it is possible to suppress the stirring resistance and reduce the torque loss of the speed reduction unit B. Furthermore, by disposing the rotary pump 51 in the housing 22, it is possible to prevent the in-wheel motor drive device 21 from being enlarged as a whole.

  As shown in FIG. 4, the wheel hub bearing portion C includes a wheel hub 32 fixedly connected to the wheel-side rotation member 28, and a wheel hub bearing that rotatably holds the wheel hub 32 with respect to the housing 22 f of the speed reduction portion B. 33. The wheel hub 32 has a cylindrical hollow portion 32a and a flange portion 32b. The drive wheel 14 is fixedly connected to the flange portion 32b by a bolt 32c. A spline and a male screw are formed on the outer diameter surface of the shaft portion 28b of the wheel side rotation member 28. A spline hole is formed in the inner diameter surface of the hollow portion 32 a of the wheel hub 32. Then, the wheel-side rotating member 28 is screwed onto the inner diameter surface of the wheel hub 32, and both ends are fastened by fastening the tip with a nut 32d.

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

  The outer member 33d of the wheel hub bearing 33 is fixed to the speed reduction unit housing 22b by fastening bolts 71.

  The outer member 33d of the wheel hub bearing 33 is provided with a flange portion 33h on the outer diameter portion and a cylindrical portion 33i on the speed reduction portion B side.

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

  Thereby, when the motor side rotation member 25 connected to the rotor 24 rotates, the curved plates 26 a and 26 b revolve around the rotation axis of the motor side rotation member 25. At this time, the outer pin 27 engages with the curved waveform of the curved plates 26 a and 26 b to cause the curved plates 26 a and 26 b to rotate in the direction opposite to the rotation of the motor-side rotating member 25.

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

  At this time, since the rotation of the motor-side rotating member 25 is decelerated by the speed reducing portion B and transmitted to the wheel-side rotating member 28, it is necessary for the drive wheel 14 even when the low torque, high rotation type motor portion A is adopted. It is possible to transmit an appropriate torque.

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

  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. Moreover, since the frictional resistance is reduced by providing the needle roller bearings 27a and 31a at the positions where the outer pins 27 and the inner pins 31 come into contact with the curved plates 26a and 26b, the transmission efficiency of the speed reducing portion B is improved. .

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

  In the above embodiment, the example in which the circulating oil passage 22c is provided inside the housing 22 has been shown. However, the present invention is not limited to this. For example, a circulating oil passage is provided outside the in-wheel motor drive device 21. Also good.

  In the above-described embodiment, the example in which the lubricating oil supply port 25d is provided in the eccentric portions 25a and 25b has been described. However, the present invention is not limited to this, and the lubricating oil supply port 25d can be provided at an arbitrary position. However, from the viewpoint of stably supplying the lubricating oil to the rolling bearing 41, the lubricating oil supply port 25d is preferably provided in the eccentric portions 25a and 25b.

  In the above-described embodiment, the example in which the rotary pump 51 is driven by using the rotation of the wheel-side rotary member 28 is shown. However, the rotary pump 51 is driven by using the rotation of the motor-side rotary member 25. You can also. However, since the rotation speed of the motor side rotation member 25 is larger than that of the wheel side rotation member 28 (11 times in the above embodiment), the durability of the rotary pump 51 may be reduced. Further, even when connected to the wheel-side rotating member 28, a sufficient discharge amount can be ensured. From these viewpoints, the rotary pump 51 is preferably driven by utilizing the rotation of the wheel-side rotary member 28.

  Moreover, in said embodiment, although the example of the cycloid pump was shown as the rotary pump 51, it is not restricted to this, All the rotary pumps driven using the rotation of the wheel side rotation member 28 are employable. it can.

  In the above embodiment, the two curved plates 26a and 26b of the speed reduction unit B are provided with 180 ° phase shifts. However, the number of the curved plates can be arbitrarily set. When three are provided, it is preferable to change the phase by 120 °.

  In addition, although the motion conversion mechanism in the above-described embodiment has been shown as an example including the inner pin 31 fixed to the wheel side rotation member 28 and the through hole 30a provided in the curved plates 26a and 26b, Without being limited to the above, it is possible to adopt an arbitrary configuration capable of transmitting the rotation of the speed reduction unit B to the wheel hub 32. For example, it may be a motion conversion mechanism composed of an inner pin fixed to a curved plate and a hole formed in the wheel side rotation member.

  In addition, although description of the action | operation in said embodiment was performed paying attention to rotation of each member, the motive power containing a torque is actually transmitted from the motor part A to a driving wheel. Therefore, the power decelerated as described above is converted into high torque.

  Further, in the description of the operation in the above embodiment, power is supplied to the motor unit A to drive the motor unit A, and the power from the motor unit A is transmitted to the drive wheels 14, but on the contrary, When the vehicle decelerates or goes down a hill, the power from the drive wheel 14 side is converted into high-rotation and low-torque rotation by the deceleration unit B and transmitted to the motor unit A, and the motor unit A generates power. May be. Furthermore, the electric power generated here may be stored in a battery, and the motor unit A may be driven later, or used for the operation of other electric devices provided in the vehicle.

  Further, a brake can be added to the configuration of the above embodiment. For example, in the configuration of FIG. 1, the housing 22 is extended in the axial direction to form a space on the right side of the rotor 24 in the drawing, a rotating member that rotates integrally with the rotor 24, and the housing 22 cannot rotate and is axially A parking brake that locks the rotor 24 by disposing a movable piston and a cylinder that operates the piston and fitting the piston and the rotating member when the vehicle is stopped may be used.

  Alternatively, it may be a disc brake that sandwiches a flange formed on a part of a rotating member that rotates integrally with the rotor 24 and a friction plate installed on the housing 22 side with a cylinder installed on the housing 22 side. Furthermore, a drum brake can be used in which a drum is formed on a part of the rotating member, a brake shoe is fixed to the housing 22 side, and the rotating member is locked by friction engagement and self-engagement.

  In the above embodiment, an example of a cylindrical roller bearing is shown as a bearing for supporting the curved plates 26a and 26b. However, the present invention is not limited to this, and for example, a plain bearing, a cylindrical roller bearing, a tapered roller bearing, and a needle roller Regardless of whether it is a plain bearing or a rolling bearing, such as a bearing, a self-aligning roller bearing, a deep groove ball bearing, an angular contact ball bearing, or a four-point contact ball bearing, whether the rolling element is a roller or a ball Furthermore, any bearing can be applied regardless of whether it is a double row or a single row. Similarly, any type of bearing can be adopted for bearings arranged in other locations.

  However, the deep groove ball bearing has a higher allowable limit speed than the cylindrical roller bearing, but has a low load capacity. Therefore, in order to obtain a necessary load capacity, a large deep groove ball bearing must be employed. Therefore, from the viewpoint of making the in-wheel motor drive device 21 compact, a cylindrical roller bearing is suitable for the rolling bearing 41.

  In each of the above-described embodiments, an example in which a radial gap motor is adopted as the motor unit A has been described. However, the present invention is not limited to this, and a motor having an arbitrary configuration can be applied. For example, it may be an axial gap motor including a stator fixed to the housing and a rotor disposed at a position facing the inner side of the stator with a gap in the axial direction.

  Moreover, in each said embodiment, although the example of the in-wheel motor drive device 21 which employ | adopted the cycloid deceleration mechanism as the deceleration part B was shown, it is not restricted to this, Arbitrary deceleration mechanisms can be employ | adopted. For example, a planetary gear reduction mechanism, a parallel shaft gear reduction mechanism, or the like is applicable.

  Furthermore, although the electric vehicle 11 shown in FIG. 8 showed the example which used the rear wheel 14 as the driving wheel, it is not restricted to this, The front wheel 13 may be used as a driving wheel and may be a four-wheel driving vehicle. . In the present specification, “electric vehicle” is a concept including all vehicles that obtain driving force from electric power, and should be understood as including, for example, a hybrid vehicle.

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

DESCRIPTION OF SYMBOLS 11 Electric vehicle 12 Chassis 12a Wheel housing 12b Suspension device 13 Front wheel 14 Rear wheel 22 Housing 22c Circulating oil path 22d Lubricating oil storage part 22e Circulating oil path 22f Reduction part housing 22g Motor part housing 23 Stator 24 Rotor 25 Motor side rotating member 25a Rotor portion 25b Hollow portion 26 Input shafts 25a, 25b Eccentric portions 26a, 26b Curved plate 27 Outer pin 29 Counterweight 31 Inner pin 51 Rotating pump 61 Pipe 62 Drain hole 63 Bolt 64 Fin

Claims (11)

A motor unit that rotationally drives the motor side rotating member (25), a speed reducing unit that decelerates the rotation of the motor side rotating member (25) and transmits the rotation to the wheel side rotating member (28), the motor unit, and the speed reducing unit A wheel hub fixedly connected to the wheel-side rotating member (28), and a speed reducer lubrication mechanism for supplying lubricating oil to the speed reducer, wherein the speed reducer lubrication mechanism comprises: Lubricating oil passage (25c) provided inside the motor-side rotating member (25), and a lubricating oil supply port extending from the lubricating oil passage (25c) toward the outer diameter surface of the motor-side rotating member (25) ( 25d), a lubricating oil discharge port (22b) for discharging lubricating oil from the housing (22f) holding the speed reduction portion, the lubricating oil discharge port (22b) and the lubricating oil passage (25c), The lubricating oil outlet (22 ) And the circulating oil passage (22e) for returning the lubricating oil discharged to the lubricating oil passage (25c) and the housing (22), and utilizing the rotation of the wheel side rotating member (28). An in-wheel motor drive device comprising a rotary pump (51) for circulating lubricating oil;
A lubricating oil reservoir (22d) is provided below the outer diameter of the motor part of the housing (22g) that holds the outer diameter of the motor part, and the outer diameter of the motor part that partitions the lubricating oil reservoir (22d) is set. The holding housing (22g) is provided with a lubricating oil discharge port (22c) for communicating the inside of the motor portion and the lubricating oil storage portion (22d), and at least one location of the housing (22f) holding the outer diameter of the speed reducing portion Provided with a lubricating oil discharge port (22b) that communicates the inside of the lower part of the speed reduction part and the inside of the lower part of the motor part, and is lower than the outer diameter of the motor part of the housing (22g) that holds the outer diameter of the motor part. In-wheel motor drive device characterized in that the lubricating oil stored in the lubricating oil storage section (22d) on the side is recirculated to the lubricating oil passage (25c) through the circulating oil passage (22e) by the rotary pump (51) .   The in-wheel motor drive device of Claim 1 with which a part of said lubricating oil storage part (22d) is extended in the lower part of the housing (22f) holding the said deceleration part.   The in-wheel motor drive device of Claim 1 or 2 with which the fin (64) for air cooling is provided in the outer surface of the said lubricating oil storage part (22d).   The in-wheel motor according to any one of claims 1 to 3, wherein the lubricating oil reservoir (22d) is made of a casting, and the air cooling fin (64) is also formed integrally with the lubricating oil reservoir (22d). Drive device.   The in-wheel motor drive device according to any one of claims 1 to 4, wherein the lubricating oil storage part (22d) and a housing (22g) for holding the motor part are integrated.   The in-wheel motor drive device according to any one of claims 1 to 5, wherein the rotary pump (51) is a cycloid pump. The in-wheel motor drive device according to any one of claims 1 to 6, wherein said rotary pump (51) drives with the number of rotations after deceleration of a motor part.   The in-wheel motor according to any one of claims 1 to 7, wherein a pipe (61) for sucking up lubricating oil from the lubricating oil reservoir (22d) is screwed to a housing (22g) of the motor unit. Drive device.   The in-wheel motor drive device according to any one of claims 1 to 7, wherein a pipe (61) for sucking up lubricating oil from the lubricating oil reservoir (22d) is press-fitted into a housing of the motor unit.   The in-wheel motor drive device according to any one of claims 1 to 7, wherein a pipe (61) for sucking up lubricating oil from the lubricating oil reservoir (22d) is formed integrally with a housing of the motor unit. . The in-wheel motor drive device according to any one of claims 8 to 10, wherein a pipe (61) for sucking up lubricating oil from the lubricating oil reservoir (22d) and a drain hole are arranged coaxially.

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