JP5010484B2 - Cycloid reducer and 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 reduction gear.

  A conventional in-wheel motor drive device 101 is described in, for example, Japanese Patent Application Laid-Open No. 2006-258289 (Patent Document 1). Referring to FIG. 12, an in-wheel motor drive device 101 includes a motor unit 103 that generates a driving force inside a casing 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 portion 105 that reduces the rotation and transmits the reduced speed to the wheel hub bearing portion 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. Therefore, a cycloid reducer that is compact and can provide a high reduction ratio may be employed as the reduction unit 105.

Moreover, the speed reduction part 105 to which the conventional cycloid reduction gear is applied includes a motor-side rotating member 106 having eccentric parts 106a and 106b, curved plates 107a and 107b disposed on the eccentric parts 106a and 106b, and curved plates 107a and 107b. A rolling bearing 111 that rotatably supports the motor-side rotating member 106, a plurality of outer pins 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 an inner pin 109 that transmits the rotation of the curved plates 107a and 107b to the wheel-side rotating member 110. In addition, an inner pin collar 109a is disposed at a portion of the inner pin 109 that contacts the curved plates 107a and 107b in order to reduce contact resistance.
JP 2006-258289 A

  In the in-wheel motor drive device 101 configured as described above, lubricating oil is sealed inside the speed reduction unit 105, and the contact portions between the curved plates 107 a and 107 b and the outer pins 108 and the inner pins 109 and the raceway surface of the rolling bearing 111. Etc.

  However, the lubricating oil is biased radially outward due to the centrifugal force accompanying the rotation of the motor-side rotating member 106 and the curved plates 107a and 107b, and the amount of lubricating oil around the motor-side rotating member 106 decreases. On the other hand, when the amount of lubricating oil enclosed in the speed reduction unit 105 is increased in order to secure the amount of lubricating oil around the motor-side rotating member 106, torque loss increases as the stirring resistance increases. In particular, if the lubricating oil is insufficient between the inner pin 109 and the inner pin collar 109a, the contact resistance with the curved plates 107a and 107b increases, and there is a risk of causing wear and seizure.

  Accordingly, an object of the present invention is to provide a cycloid reduction gear capable of stably supplying lubricating oil between an inner pin and an inner pin collar, and an in-wheel motor drive device employing such a cycloid reduction gear. is there.

The cycloid reducer according to the present invention includes an input-side rotating member having an eccentric portion, an output-side rotating member, and an eccentric portion that is rotatably held by the rotation of the input-side rotating member. A revolving member that performs a revolving motion, an outer peripheral engagement member that engages with an outer peripheral portion of the revolving member to cause the revolving member to rotate, and a revolving member that revolves around the rotation axis of the input side rotating member. And a motion conversion mechanism that converts the rotational motion into an output-side rotating member. The motion conversion mechanism is formed on a revolving member and a plurality of inner pins that are provided on a circumferential track centering on the rotation axis of the output side rotating member and whose one end in the axial direction is held by the output side rotating member. A plurality of holes that are larger in diameter than the outer diameter of the inner pin and receive the inner pin, an inner pin collar that is rotatably fitted to the inner pin at a position facing the inner wall surface of the hole, and an inner pin collar shaft and a Luz last plate to restrict the movement inside the pin axial end surface of the collar of the circular path outer portion the axial direction of the inner pin collar abuts with distance from the circular path inside portion of the end face. The lubricating oil blown by the centrifugal force from the input side rotating member is supplied between the inner pin and the inner pin collar from the inner circumferential portion of the circumferential end of the axial end surface of the inner pin collar. And

  With the above configuration, the lubricating oil can be stably supplied between the inner pin and the inner pin collar. As a result, a highly reliable cycloid reducer that prevents wear or seizure can be obtained.

As one embodiment, the thrust plate is a disk-shaped member having a through hole formed in the center, and a predetermined gap is provided between the inner circumferential surface of the inner pin collar and the inner circumferential surface of the inner pin collar in a region along the inner circumferential surface. An inner region facing each other, an outer region in contact with the outer peripheral portion of the circumferential end of the axial end surface of the inner pin collar on the radially outer side from the inner region, and an inner pin formed across the inner region and the outer region. look including a plurality of recesses for receiving, between the inner pin and the inner pin collar, the lubricating oil is supplied via a predetermined gap. An oil sump is formed between the thrust plate and the inner pin collar, and lubricating oil is supplied between the inner pin and the inner pin collar.

As another embodiment, the thrust plate is a disk-shaped member having a through hole formed in the center, and is in a position in contact with the through hole of the wall surface that contacts the outer circumferential portion of the axial end surface of the inner pin collar. , it looks including a plurality of first recess receiving a portion of the inner pin, between the inner pin and the inner pin collar, lubrication from the remaining part of the pin inside which is located the through-holes protrudes from the first recess Oil is supplied . An oil sump is formed between the thrust plate and the inner pin collar, and lubricating oil is supplied between the inner pin and the inner pin collar.

Preferably, the thrust plate further includes a plurality of second recesses formed so as to surround the first recess and receiving the outer circumferential portion of the axial end portion of the inner pin collar. The outer edge portion of the second recess comes into contact with the outer diameter surface of the inner pin collar. As a result, it is possible to effectively prevent the lubricating oil from flowing out from the radial end of the inner pin collar.

  Preferably, the inner pin collar has an oil drain passage that penetrates in a radial direction and discharges lubricating oil between the inner pin and the inner pin collar. As a result, the lubricating oil does not stay between the inner pin and the inner pin collar, so that an increase in temperature can be suppressed.

Preferably, the cycloid reducer has a plurality of revolution members. The oil drainage path is disposed in a region between adjacent revolution members. And between the adjacent revolution members, it is further provided with an inscribed ring that is arranged on the inner side of the circumferential track and inscribed in the plurality of inner pin collars . An oil sump for lubricating oil is formed in a space surrounded by the inner peripheral surface of the inner ring and the revolution members adjacent to each other . The inscribed ring can suppress the inclination of the revolving member in the axial direction and can prevent the lubricating oil from flowing in from the oil drain passage.

  The in-wheel motor drive device according to the present invention includes a motor unit that rotationally drives a motor-side rotating member as an input-side rotating member, and any one of the above that decelerates the rotation of the motor-side rotating member and transmits it to the wheel-side rotating member. And a wheel hub fixedly connected to a wheel-side rotating member as an output-side rotating member.

  According to the present invention, the lubricating oil can be stably supplied between the inner pin and the inner pin collar. As a result, an in-wheel motor drive device having excellent durability and high reliability can be obtained.

  With reference to FIGS. 1-8, the in-wheel motor drive device 21 which concerns on one Embodiment of this invention is demonstrated.

  FIG. 7 is a schematic view of an electric vehicle 11 that employs an in-wheel motor drive device 21 according to an embodiment of the present invention. FIG. 8 is a schematic view of the electric vehicle 11 as viewed from the rear. Referring to FIG. 7, an electric vehicle 11 includes an in-wheel motor drive device that transmits driving force to a chassis 12, front wheels 13 as steering wheels, rear wheels 14 as drive wheels, and left and right rear wheels 14. 21. Referring to FIG. 8, the rear wheel 14 is accommodated in a wheel housing 12a of the chassis 12, and is fixed to the lower portion of the chassis 12 via a suspension device (suspension) 12b.

  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 is provided at the 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.

  With reference to FIGS. 1-6, the in-wheel motor drive device which concerns on one Embodiment of this invention is demonstrated. 1 is a schematic cross-sectional view of the in-wheel motor drive device, FIG. 2 is a cross-sectional view taken along II-II in FIG. 1, FIG. 3 is an enlarged view around the eccentric portions 25a and 25b, and FIG. 5, 5 and 6 show the thrust plate 51. FIG.

  First, referring to FIG. 1, an in-wheel motor drive device 21 as an example of a vehicle deceleration unit 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, A wheel hub bearing portion C for transmitting the output from the speed reduction portion B to the drive wheel 14 is provided. The motor portion A and the speed reduction portion B are accommodated in the casing 22 and, as shown in FIG. Installed inside.

  The motor part A includes a stator 23 fixed to the casing 22, a rotor 24 disposed at a position facing the inner side of the stator 23 with a radial gap, and a rotor 24 fixedly connected to the inner side of the rotor 24. It is a radial gap motor provided with the motor side rotation member 25 which rotates integrally. Further, a sealing member 39 is provided on the end surface of the motor part A opposite to the speed reducing part B in order to prevent dust from entering the motor part A.

  The rotor 24 has a flange-shaped rotor portion 24 a and a cylindrical hollow portion 24 b, and is rotatably supported by the casing 22 by a rolling bearing 34. In addition, a sealing member 35 is provided between the casing 22 and the rotor 24 in order to prevent the lubricant encapsulated in the speed reduction part B from entering the motor part A.

  The motor-side rotation member 25 is disposed 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 rolling bearings 36a and 36b at both ends of the speed reduction unit B. Further, the two eccentric portions 25a and 25b are provided with a 180 ° phase change in order to cancel the centrifugal force due to the eccentric motion.

  The deceleration part B is held at a fixed position on the casing 22 and curved plates 26a and 26b as revolving members that are rotatably held by the eccentric parts 25a and 25b, and engages with the outer peripheral parts 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 26 a and 26 b to the wheel-side rotation member 28, and a counterweight 29 are provided. 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.

  2 and 3, the curved plate 26a has a plurality of corrugations composed of trochoidal curves such as epitrochoids on the outer periphery, and a plurality of through holes penetrating from one end face to the other end face. 30a and 30b. A plurality of through holes 30a are provided at equal intervals on the circumference centered on the rotation axis of the curved plate 26a, and receive an inner pin 31 described later. Further, the through hole 30b is provided at the center of the curved plate 26a and is fitted to the eccentric portion 25a.

  The curved plate 26a is rotatably supported by the rolling bearing 41 with respect to the eccentric portion 25a. Referring to FIG. 3, this rolling bearing 41 is fitted to the outer diameter surface of the eccentric portion 25a, and the inner ring member 42 having an inner raceway surface 42a on the outer diameter surface, and the inner diameter of the through hole 30b of the curved plate 26a. The outer raceway surface 43 formed directly on the surface, a plurality of cylindrical rollers 44 disposed between the inner raceway surface 42a and the outer raceway surface 43, and a retainer (not shown) that keeps an interval between the adjacent cylindrical rollers 44 It is a cylindrical roller bearing provided with.

  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 are engaged to cause the curved plates 26a and 26b to rotate. Further, in order to reduce the frictional resistance with the curved plates 26a and 26b, needle roller bearings 27a are provided at positions where they abut against the outer peripheral surfaces of the curved plates 26a and 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 counteract the unbalanced inertia couple generated by the rotation of the curved plates 26a and 26b. The eccentric portions adjacent to the eccentric portions 25a and 25b are arranged with a 180 ° phase change.

Here, referring to FIG. 3, if the center point between the two curved plates 26a, 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. The sum of masses of L ₁ , the curved plate 26 a, the rolling bearing 41, and the eccentric portion 25 a is m ₁ , and the eccentric amount of the center of gravity of the curved plate 26 a from the rotational axis is ε ₁ . L ₁ × m ₁ × ε ₁ = L ₂ × m ₂ × ε ₂ , where L _{2 is} the distance, m _{2 is} the weight of the counterweight 29, and ε ₂ is the amount of eccentricity of the center of gravity of the counterweight 29 from the rotational axis. It is a relationship that satisfies A similar relationship is also established between the curved plate 26b on the left side of the center point G in FIG.

  Referring to FIG. 4, the motion conversion mechanism includes a plurality of inner pins 31 held by wheel-side rotating member 28 and through holes 30 a provided in curved plates 26 a and 26 b.

  The inner pins 31 are provided at equal intervals on a circumferential track centering on the rotation axis of the wheel side rotation member 28, and are fixed to the wheel side rotation member 28. Further, in order to reduce the frictional resistance with the curved plates 26a, 26b, needle roller bearings 31a serving as inner pin collars are provided at positions that contact the inner wall surfaces of the through holes 30a of the curved plates 26a, 26b. The needle roller bearing 31a is provided with an oil drain passage 31b that penetrates in the radial direction and discharges lubricating oil between the inner pin 31 and the needle roller bearing 31a. In this embodiment, the oil drain passage 31b is disposed in a region between the adjacent curved plates 26a and 26b.

  Further, thrust plates 51 and 52 are provided at both axial ends of the needle roller bearing 31a. The thrust plates 51 and 52 are disposed at a position where the axial movement of the needle roller bearing 31a is restricted and the lubricating oil can be supplied between the inner pin 31 and the needle roller bearing 31a.

  5 and 6, the thrust plate 51 is a disk-shaped member having a through hole 51a formed in the center, and an axial end surface of the needle roller bearing 31a is formed in a region along the inner peripheral surface thereof. The inner region 51b that faces a predetermined gap, the outer region 51c that contacts the axial end surface of the needle roller bearing 31a on the radially outer side of the inner region 51b, and the inner region 51b and the outer region 51c are formed. And a plurality of recesses 51d (through holes in this embodiment) for receiving the inner pins 31. Since the thrust plate 52 has the same configuration, the description thereof is omitted.

  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 (“maximum outer diameter including the needle roller bearing 31a”). The same shall apply hereinafter).

  Further, referring to FIG. 3 and FIG. 4, an inscribed ring 26 that is inscribed in the plurality of needle roller bearings 31a is arranged between the adjacent curved plates 26a and 26b. The inscribed ring 26 prevents the curved plates 26a and 26b from being tilted and receives the lubricating oil blown from the motor side rotating member 25 by centrifugal force between the curved plates 26a and 26b to form an oil reservoir. Lubricating oil is guided to the thrust plate 51 side from a plurality of holes 30a which are larger in diameter by a predetermined amount than the outer diameter of the inner pins 31 of the plates 26a and 26b and receive the inner pins 31.

  The speed reducer lubrication mechanism supplies lubricating oil to the speed reducer B, and includes a lubricating oil passage 25c, a lubricating oil supply port 25d, a lubricating oil discharge port 22b, a circulating oil passage 22c, and a lubricating oil storage portion. 22d and a filtering device 22e.

  The lubricating oil passage 25 c is located inside the motor side rotation 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, referring to FIG. 2, at least one portion of casing 22 at the position of speed reduction portion B is provided with a lubricating oil discharge port 22 b for discharging the lubricating oil inside speed reduction portion B. Further, the lubricating oil discharged from the lubricating oil discharge port 22b returns to the lubricating oil passage 25c via a circulating oil passage 22c that connects the lubricating oil discharge port 22b and the lubricating oil passage 25c.

  A lubricating oil reservoir 22d for storing lubricating oil is provided between the lubricating oil discharge port 22b and the circulating oil passage 22c. The lubricating oil outlet 22b is provided on the inner wall surface of the lubricating oil reservoir 22d. Thereby, at the time of high speed rotation, the lubricating oil that cannot be discharged from the lubricating oil discharge port 22b can be temporarily stored in the lubricating oil storage part 22d. As a result, an increase in torque loss of the deceleration unit B can be prevented. On the other hand, during low-speed rotation, even if the centrifugal force decreases and the amount of lubricating oil reaching the lubricating oil discharge port 22b decreases, the lubricating oil stored in the lubricating oil reservoir 22d is returned to the lubricating oil passage 25c. can do. As a result, the lubricating oil can be stably supplied to the deceleration unit B.

  Furthermore, the filtering device 22e is disposed at a position adjacent to the lubricating oil reservoir 22d of the circulating oil passage 22c. As a result, foreign matters such as wear powder can be removed from the lubricating oil discharged from the deceleration portion B and circulated, so that high lubricating performance can be maintained over a long period of time.

  The specific structure of the filtering device 22e is not particularly limited, but may be, for example, a cartridge type filter. Thereby, the maintenance of the filtration device 22e becomes easy. Moreover, the filtering device 22e can be attached to any position of the circulating oil passage 22c. In this embodiment, although the example provided adjacent to the lubricating oil storage part 22d was shown, you may provide not only in this but in the connection part vicinity of the circulating oil path 22c and the lubricating oil path 25c.

  Moreover, in said embodiment, although the example which made the lubricating oil storage part 22d and the filtration apparatus 22e a different body was shown, not only this but both can also be united. For example, a filter cartridge as a filtering device can be detachably attached to the lubricating oil reservoir 22d.

  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 portion 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.

  In particular, the lubricating oil is supplied between the inner pin 31 and the needle roller bearing 31a via a gap between the needle roller bearing 31a and the inner region 51b of the thrust plate 51, and is discharged from the oil discharge passage 31b. Discharged. Thereby, while being able to supply lubricating oil stably between the inner pin 31 and the needle roller bearing 31a, the temperature rise accompanying the retention of lubricating oil can be suppressed.

  Then, the lubricating oil that has reached the inner wall surface of the casing 22 is discharged from the lubricating oil discharge port 22b to the outside of the speed reduction unit B, and returns to the lubricating oil path 25c via the circulating oil path 22c. Here, a flow in the same direction as the rotation direction of the motor-side rotation member 25 and the revolution direction of the curved plates 26a and 26b is formed in the lubricating oil inside the speed reduction portion B. Since the lubricating oil passing through the circulating oil passage 22c reaches the lubricating oil passage 25c by the inertial force of this flow, an oil pump or the like for circulating the lubricating oil can be omitted.

  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 discharging the lubricating oil from the lubricating oil discharge port 22b, it is possible to suppress the stirring resistance and reduce the torque loss of the deceleration unit B. Furthermore, by omitting an oil pump or the like for circulating the lubricating oil, it contributes to weight reduction of the in-wheel motor drive device 21.

  The wheel hub bearing portion C includes a wheel hub 32 fixedly connected to the wheel-side rotating member 28 and a wheel hub bearing 33 that holds the wheel hub 32 rotatably with respect to the casing 22. 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. In addition, a sealing member 32d is provided at the opening of the hollow portion 32a in order to prevent dust from entering the inside of the in-wheel motor drive device 21.

  The wheel hub bearing 33 is a double-row angular ball bearing that employs balls 33e as rolling elements. As the raceway surfaces of the balls 33e, a first outer raceway surface 33a (right side in the figure) and a second outer raceway surface 33b (left side in the figure) are provided on the inner diameter surface of the outer member 22a. A first inner raceway surface 33c facing the surface 33a is an outer diameter surface of the inner ring member 33h fitted and fixed to the wheel-side rotating member 28, and a second inner raceway surface 33d facing the second outer raceway surface 33b is a wheel hub. It is provided on each of the 32 outer diameter surfaces. A plurality of balls 33e are arranged between the first outer raceway surface 33a and the first inner raceway surface 33c and between the second outer raceway surface 33b and the second inner raceway surface 33d. The wheel hub bearing 33 includes a retainer 33f that holds the left and right rows of balls 33e, and a sealing member 33g that prevents leakage of a lubricant such as grease enclosed in the bearing and dust from the outside. Including.

  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 (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. Further, the provision of the needle roller bearings 27a, 31a at the positions where the outer pins 27 and the inner pins 31 come into contact with the curved plates 26a, 26b reduces the frictional resistance, thereby improving the transmission efficiency of the speed reducing portion B. .

  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.

  Next, modified examples of the thrust plates 51 and 52 will be described with reference to FIGS. First, the thrust plate 61 is a disk-shaped member having a through hole 61a formed in the center. A plurality of first recesses 61b (through holes in this embodiment) that receive the inner pins 31 at positions that contact the through-holes 61a of the wall surface that abuts the axial end surface of the needle roller bearing 31a, and the first recesses 61b. And has a plurality of second recesses 61c for receiving the axial ends of the needle roller bearings 31a.

  According to the thrust plate 61 having the above-described configuration, the lubricating oil is supplied from the portion protruding from the inner pin 31 and the through hole 61a of the needle roller bearing 31a. Moreover, since the outer edge part of the 2nd recessed part 61b contact | abuts the outer diameter surface of the needle roller bearing 31a, it can prevent effectively that lubricating oil flows out from the axial direction edge part of the needle roller bearing 31a. it can.

  In the above embodiment, an example of the circulating oil passage 22c that passes through the outside of the in-wheel motor drive device 21 has been shown. However, the present invention is not limited to this, and for example, a circulating oil passage may be provided inside the casing 22. Good. In this case, since the circulating oil passage cannot be made very large from the viewpoint of the rigidity of the casing 22, it is desirable to provide a plurality of circulating oil passages in order to secure a necessary oil supply amount.

  Further, in the above-described embodiment, the example in which the lubricating oil supply port 25d is provided in the eccentric portions 25a and 25b is shown, but 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.

  Further, in the above embodiment, two curved plates 26a and 26b of the deceleration 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 °.

  Further, in the above embodiment, the example in which the needle roller bearing 31a is adopted as the inner pin collar is shown. However, the present invention is not limited to the rolling bearing, and the effect of the present invention can be obtained even with a sliding bearing.

  Further, the material of the thrust plates 51, 52, 61, 62 in the above embodiment is not limited. For example, it may be a metal or a resin. The same applies to the inscribed ring 26.

  Moreover, although the motion conversion mechanism in said embodiment showed the example comprised by the inner pin 31 fixed to the wheel side rotation member 28, and the through-hole 30a provided in the curve boards 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 used later for driving the motor unit A or for operating 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 casing 22 is extended in the axial direction to form a space on the right side of the rotor 24 in the drawing, the rotating member that rotates integrally with the rotor 24, and the casing 22 is non-rotatable and axial. 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 in which a flange formed on a part of a rotating member that rotates integrally with the rotor 24 and a friction plate installed on the casing 22 side are sandwiched by a cylinder installed on the casing 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 casing 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 required 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 casing and a rotor disposed at a position facing the inner side of the stator with an axial gap.

  Furthermore, although the electric vehicle 11 shown in FIG. 7 has shown 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.

It is a figure which shows the in-wheel motor drive device which concerns on one Embodiment of this invention. It is sectional drawing in II-II of FIG. It is an enlarged view of the eccentric part periphery of FIG. FIG. 2 is an enlarged view around an inner pin in FIG. 1. It is a front view of the thrust plate of FIG. It is sectional drawing in VI-VI of FIG. It is a top view of the electric vehicle which has the in-wheel motor drive device of FIG. FIG. 8 is a rear sectional view of the electric vehicle of FIG. 7. FIG. 5 is an in-wheel motor drive device according to another embodiment of the present invention, corresponding to FIG. 4. FIG. 10 is a front view of the thrust plate of FIG. 9. It is sectional drawing in XI-XI of FIG. It is a figure which shows the conventional in-wheel motor drive device.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 Electric vehicle, 12 Chassis, 12a Wheel housing, 12b Suspension device, 13 Front wheel, 14 Rear wheel, 21,101 In-wheel motor drive device, 22,102 Casing, 22a Outer member, 22b Lubricating oil discharge port, 22c Circulating oil Road, 22d Lubricating oil reservoir, 22e Filtration device, 23 Stator, 24 Rotor, 24a Rotor, 28a, 32b Flange, 24b, 32a Hollow, 28b Shaft, 25, 106 Motor side rotating member, 25a, 25b, 106a, 106b Eccentric part, 25c Lubricating oil passage, 25d Lubricating oil supply port, 26 Internal ring, 26a, 26b, 107a, 107b Curved plate, 27, 108 Outer pin, 27a, 31a Needle roller bearing, 28, 110 Wheel Side rotating member, 29 counterweight, 30a, 30b through Hole, 31, 109 inner pin, 32 wheel hub, 32d, 33g, 35, 39 sealing member, 33 wheel hub bearing, 40 plastic joint, 33a, 33b, 43 outer raceway surface, 33c, 33d, 42a inner raceway surface, 42b opening, 33e ball, 33f cage, 33h, 42 inner ring member, 34, 36a, 36b, 41, 111 rolling bearing, 44 cylindrical roller, 51, 52, 61, 62 thrust plate, 51a, 61a through hole, 51b Inner area, 51c Outer area, 51d, 61b, 61c Recess, 109a Inner pin collar.

Claims (7)

An input side rotating member having an eccentric part;
An output side rotating member;
A revolving member that is rotatably held by the eccentric part and performs a revolving motion around its rotational axis as the input side rotating member rotates.
An outer periphery engaging member that engages with an outer peripheral portion of the revolving member to cause rotation of the revolving member;
A rotation conversion mechanism that converts the rotation motion of the revolution member into a rotation motion around the rotation axis of the input side rotation member and transmits the rotation motion to the output side rotation member;
The motion conversion mechanism is
A plurality of inner pins provided on a circumferential track centering on the rotation axis of the output-side rotating member and having one end in the axial direction held by the output-side rotating member;
A plurality of holes that are formed in the revolving member and have a diameter larger than the outer diameter of the inner pin by a predetermined amount, and receive the inner pin;
An inner pin collar that is rotatably fitted to the inner pin at a position facing the inner wall surface of the hole;
It restricts the movement of the circular path outer portion abuts with the axial direction of the inner pin collar of the axial end surface of the inner pin collar together away from said circular path inside portion of the axial end surface of the inner pin collar and a scan last plate seen including,
Lubricating oil blown off by centrifugal force from the input side rotating member is configured to be supplied between the inner pin and the inner pin collar from the inner circumferential portion of the circumferential track on the axial end surface side of the inner pin collar. A cycloid reducer characterized by that. The thrust plate is a disk-shaped member having a through hole formed in the center,
An inner region facing the inner peripheral surface of the inner pin collar with a predetermined gap from the inner circumferential portion of the circumferential orbit of the inner pin collar in a region along the inner peripheral surface;
An outer region in contact with the outer circumferential portion of the axial end surface of the inner pin collar on the radially outer side from the inner region;
A plurality of recesses for receiving the inner pin formed across the inner region and the outer region,
The cycloid reduction gear according to claim 1, wherein lubricating oil is supplied between the inner pin and the inner pin collar via the gap. The thrust plate is a disk-shaped member having a through hole formed in the center,
A plurality of first recesses for receiving a part of the inner pin at a position in contact with the through hole of the wall surface in contact with the outer circumferential portion of the circumferential end of the axial end surface of the inner pin collar;
2. The cycloid according to claim 1, wherein lubricating oil is supplied between the inner pin and the inner pin collar from a remaining part of the inner pin that protrudes from the first recess and is located in the through hole. Decelerator. 4. The thrust plate according to claim 3, further comprising a plurality of second recesses formed so as to surround the first recess and receiving the outer circumferential portion of the circumferential end of the axial end portion of the inner pin collar. Cycloid reducer.   The cycloid reduction gear according to any one of claims 1 to 4, wherein the inner pin collar has an oil drain passage that penetrates in a radial direction and discharges lubricating oil between the inner pin and the inner pin collar. The cycloid reducer has a plurality of the revolution members,
The oil drainage path is disposed in a region between the adjacent revolution members,
An inscribed ring arranged between the adjacent revolution members and arranged inside the circumferential track and inscribed in the plurality of inner pin collars ,
The cycloid reduction gear according to claim 5, wherein an oil sump for lubricating oil is formed in a space surrounded by an inner peripheral surface of the inner ring and the revolving members adjacent to each other . A motor unit for rotationally driving the motor side rotating member as the input side rotating member;
The cycloid reducer according to any one of claims 1 to 6, wherein the rotation of the motor side rotation member is decelerated and transmitted to the wheel side rotation member;
An in-wheel motor drive device comprising: a wheel hub fixedly connected to a wheel side rotation member as an output side rotation member.

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