JP2009012569A - In-wheel motor drive device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an in-wheel motor drive device enhanced in durability and improved in reliability by so forming as to stably supply lubricating oil to all areas of a reduction part. <P>SOLUTION: This in-wheel motor drive device 21 comprises a motor part A, the reduction part B, a wheel hub 32, and a reduction part lubricating mechanism for supplying the lubricating oil to the reduction part. The reduction part lubricating mechanism comprises a spiral lubricating oil path 25c positioned in a motor side rotating member 25 and extending in the flowing direction of the lubricating oil and in the rotating direction opposite to the rotating direction of the motor side rotating member 25, a lubricating oil supply port 25d extending from the lubricating oil path 25c toward the outer diameter surface of the motor side rotating member 25, a lubricating oil discharge port 22b for discharging the lubricating oil into a casing 2, a circulating oil path 22c for connecting the lubricating oil discharge port 22b to the lubricating oil path 25c, and a filtering device 22e disposed in the circulating oil path 22c and filtrating the lubricating oil. <P>COPYRIGHT: (C)2009,JPO&INPIT

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. 7, 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.
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. And this tendency becomes remarkable with the high rotation of the motor side rotation member 106.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an in-wheel motor drive device having excellent durability and high reliability by adopting a structure capable of stably supplying lubricating oil to the entire speed reducing portion.

  An in-wheel motor drive device according to the present invention includes: a motor unit that rotationally drives a motor-side rotating member; a deceleration unit that is covered by a casing and decelerates the rotation of the motor-side rotating member and transmits the rotation to the wheel-side rotating member; A wheel hub fixedly connected to the side rotation member; and a speed reduction part lubrication mechanism for supplying lubricating oil to the speed reduction part. The speed reducer lubrication mechanism is located inside the motor-side rotating member, and extends in the direction opposite to the rotation direction of the motor-side rotating member toward the direction in which the lubricating oil flows, and the lubricating oil path from the lubricating oil path to the motor side Connect the lubricating oil supply port extending toward the outer diameter surface of the rotating member, the lubricating oil discharge port for discharging the lubricating oil from the speed reducer to the casing, and connect the lubricating oil discharge port and the lubricating oil passage from the lubricating oil discharge port. A circulation oil passage that supplies the discharged lubricating oil to the lubricating oil passage, and a filtration device that is disposed in the circulating oil passage and filters the lubricating oil are included.

  In the in-wheel motor drive device having the above-described configuration, by providing a helical lubricating oil passage inside the motor-side rotating member, a flow of lubricating oil is formed with the rotation of the motor-side rotating member. Thereby, even if it does not use an oil pump etc. for supply of lubricating oil, lubricating oil can be stably supplied to a deceleration part.

  Further, since the lubricating oil biased radially outward is discharged from the lubricating oil discharge port, it is possible to prevent an increase in torque loss due to an increase in the amount of lubricating oil in the speed reduction portion. Furthermore, since the motor-side rotating member and the revolving member are rotated, a flow in the rotational direction of the motor-side rotating member is formed in the lubricating oil in the speed reducing unit. Therefore, the lubricating oil is circulated in the speed reducing unit using this flow. Can do.

  Accordingly, the lubricating oil can be stably supplied to the entire speed reducing portion, and a pump or the like is not used for circulating the lubricating oil, which contributes to the weight reduction of the in-wheel motor drive device. As a result, an in-wheel motor drive device having excellent durability and high reliability can be obtained.

  Furthermore, by providing a filtration device that removes foreign matter from the lubricating oil discharged from the speed reduction portion, high lubricating performance can be maintained over a long period of time.

  As one embodiment, the lubricating oil passage rotates on the motor side in a direction in which the lubricating oil flows on the outer wall surface of the linear flow passage, and the straight flow passage linearly extending along the rotation axis inside the motor side rotation member. And a spiral groove extending in the opposite direction to the rotation direction of the member. The lubricating oil passage according to this embodiment can be obtained, for example, by tapping a straight passage.

  As another embodiment, the lubricating oil passage has a linear flow path extending linearly along the rotation axis inside the motor side rotating member, and a winding direction arranged along the outer wall surface of the linear flow path is on the motor side. A coil spring opposite to the rotating direction of the rotating member. According to this embodiment, the helical lubricating oil passage can be formed more easily and at a lower cost. Further, the shape of the lubricating oil passage can be easily set by adjusting the pitch and pitch angle of the coil spring.

  Preferably, the casing has a lubricating oil reservoir that stores lubricating oil. The lubricating oil outlet is provided on the inner wall surface of the lubricating oil reservoir. As a result, an increase in the stirring resistance of the speed reduction unit can be prevented, and the lubricating oil can be further stably supplied to the speed reduction unit.

  More preferably, the filtration device is a filter cartridge that is detachably attached to the lubricating oil reservoir. Replacement is facilitated by using a cartridge type filtration device. This further improves the lubrication life.

  Preferably, the speed reducing portion has a through hole that passes through the eccentric portion, and is revolved around the revolving member that rotates around the rotation axis as the motor side rotating member rotates, and is fixed to the casing. The outer periphery engaging member that engages with the outer peripheral portion of the rotating member and causes the rotating member to rotate, and the rotating member rotates to rotate around the rotation axis of the motor side rotating member to rotate the wheel side. And a counterweight that rotates integrally with the motor-side rotating member at a phase that cancels out the unbalanced inertia couple due to the eccentric motion of the revolving member at a position adjacent to the eccentric portion.

  By adopting a reduction mechanism that is compact and has a high reduction ratio as described above, sufficient torque can be transmitted to the drive wheels even when the motor portion has a low torque. As a result, a lightweight and small in-wheel motor drive device can be obtained.

  Preferably, the revolution member has a plurality of waveforms on the outer periphery thereof. The outer peripheral engagement members are a plurality of outer pins including a rolling bearing that is provided at equal intervals on a circumference centered on the rotation axis of the motor side rotation member and abuts on the outer peripheral portion of the revolution member. .

  Preferably, the motion conversion mechanism includes an inner pin provided on the wheel side rotation member, and a hole formed in the revolving member and having a diameter larger than the outer diameter of the inner pin by a predetermined amount and receiving the inner pin. The inner pin includes a rolling bearing that contacts the wall surface of the hole.

  As described above, by disposing the rolling bearings at the portions of the outer pin and the inner pin that contact the revolving member, it is possible to reduce the frictional resistance generated between the two members.

  According to the present invention, high lubrication performance can be maintained over a long period of time by circulating the lubricating oil to the speed reduction portion while removing foreign matters in the lubricating oil by the filtering device. As a result, an in-wheel motor drive device having excellent durability and high reliability can be obtained.

  With reference to FIGS. 1-5, the in-wheel motor drive device 21 which concerns on one Embodiment of this invention is demonstrated.

  FIG. 4 is a schematic view of an electric vehicle 11 employing an in-wheel motor drive device 21 according to an embodiment of the present invention, and FIG. 5 is a schematic view of the electric vehicle 11 as seen from the rear. Referring to FIG. 4, 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. 5, the rear wheel 14 is housed inside a wheel housing 12 a of the chassis 12 and is fixed to the lower portion of the chassis 12 via a suspension device (suspension) 12 b.

  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. 1-3, 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 the line II-II of FIG. 1, and FIG. 3 is an enlarged view around the eccentric portions 25a and 25b.

  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 housed 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. The shaft portion 28b has a hollow structure, and a first inner raceway surface 33c of the wheel hub bearing 33 is formed on the outer diameter surface thereof.

  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. It is arranged at a position adjacent to each eccentric part 25a, 25b with a 180 ° phase change from the eccentric part.

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.

  The motion conversion mechanism includes a plurality of inner pins 31 held by the wheel-side rotating 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 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 are provided at positions where they contact the inner wall surfaces of the through holes 30a of the curved plates 26a, 26b. 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 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 path 25c is a helical flow path that is located inside the motor-side rotating member 25 and extends in the direction opposite to the rotation direction of the motor-side rotating member 25 in the direction in which the lubricating oil flows. 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.

  Referring to FIG. 3, the lubricating oil passage 25c includes a linear flow path 25e that linearly extends in the axial direction inside the motor-side rotation member 25, and a direction in which the lubricating oil flows on the outer wall surface of the linear flow path 25e ( It is composed of a spiral groove 25f extending from the right side to the left side of FIG. In this embodiment, the spiral groove 25f is formed clockwise as viewed from the circulating oil passage 22c side (the right side in FIG. 3), so that the motor side rotating member 25 rotates counterclockwise. Will do.

  The method for forming the lubricating oil passage 25c is not particularly limited. For example, if a female screw is formed on the outer wall surface of the linear flow passage 25e by tapping, the screw groove becomes the helical groove 25f. The screw shape is not particularly limited, and may be, for example, a triangular screw or a trapezoidal screw.

  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.

  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.

  Further, since the lubricating oil passage 25c has a spiral shape, a lubricating oil flow from the circulating oil passage 22c toward the lubricating oil supply port 25d is formed as the motor-side rotating member 25 rotates. Further, as the rotational speed of the motor side rotating member 25 increases, the flow of the lubricating oil also increases.

  That is, if the rotation speed of the motor-side rotating member 25 is increased, the flow rate of the lubricating oil in the lubricating oil passage 25c is increased, and the amount of lubricating oil supplied to the speed reduction unit B is increased and the centrifugal force is also increased. The amount of lubricating oil discharged from the lubricating oil discharge port 22b also increases. On the other hand, if the rotational speed of the motor-side rotating member 25 becomes slow, both the supply amount and the discharge amount of the lubricating oil in the speed reduction unit B decrease. As a result, the lubricating oil can be circulated smoothly and smoothly without depending on the rotation state of the motor-side rotating member 25.

  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 provided on the outer diameter surface of the wheel-side rotating member 28, and a second inner raceway surface 33d facing the second outer raceway surface 33b is provided on the outer diameter surface of the wheel hub 32, respectively. ing. 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 wheel hub 32 and the wheel side rotation member 28 are fixed by diameter expansion caulking. “Diameter caulking” refers to a caulking jig (not shown) having an outer diameter slightly larger than the inner diameter of the shaft portion 28b of the wheel-side rotating member 28 in a state where the in-wheel motor driving device 21 is fixed. The wheel side rotating member 28 and the wheel hub 32 are plastically coupled by the plastic coupling portion 40 by press-fitting into the inner diameter portion 28b. By fixedly connecting the wheel-side rotating member 28 and the wheel hub 32 by the above method, the coupling strength can be significantly increased as compared with the case of fixing by fitting. Thereby, the wheel hub 32 can be stably held.

  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.

  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.

  In the above embodiment, the example in which the lubricating oil passage 25c is formed by tapping the outer wall surface of the straight flow passage 25e has been shown. However, the present invention is not limited to this, and any configuration may be adopted. it can. For example, another form of the lubricating oil passage will be described with reference to FIG. FIG. 6 is another embodiment of FIG. 3, and the basic configuration is the same as that of the in-wheel motor driving device 21.

  Referring to FIG. 6, the lubricating oil path 25 c is configured by a straight flow path 25 e and a coil spring 25 g in which the winding direction disposed on the outer wall surface of the straight flow path 25 e is opposite to the rotation direction of the motor-side rotation member 25. Is done. In this embodiment, the winding direction of the coil spring 25g is formed clockwise as viewed from the circulating oil passage 22c side (the right side in FIG. 6), so that the motor side rotating member 25 is counterclockwise. Will rotate.

  With the above configuration, the lubricating oil passage 25c can be formed easily and at a lower cost than when the outer wall surface of the straight passage 25e is tapped. In addition, since coil springs 25g having various pitches and pitch angles can be selected, the degree of freedom of the shape of the lubricating oil passage 25c is increased.

  Further, in each of the above-described embodiments, the example in which the tap process or the coil spring 25g is arranged and the entire area of the lubrication flow path 25c is a spiral flow path has been shown. However, the present invention is not limited thereto, and the lubrication flow path 25c is not limited thereto. The effect of the present invention can be obtained even if only a part of the spiral is formed. When a part of the lubrication flow path 25c is formed in a spiral shape, the position is not particularly limited. However, if the position closer to the upstream side of the lubrication oil path 25c, that is, the connection portion with the circulation oil path 22c is formed in a spiral shape, the position is further increased. High effect can be expected.

  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 °.

  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. 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.

  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. 4 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.

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. It is a top view of the electric vehicle which has the in-wheel motor drive device of FIG. FIG. 5 is a rear sectional view of the electric vehicle of FIG. 4. It is a figure corresponding to FIG. 3 of the in-wheel motor drive device which concerns on other embodiment of this invention. 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, 25e Linear flow path, 25f Spiral groove, 25g Coil spring, 26a, 26b, 107a, 107b Curved plate, 27, 108 Outer pin, 27a, 31a Needle roller bearings, 28, 110 Wheel side rotating members, 29 Counterweight, 30a, 30b Through-hole, 31,109 Inner pin, 32 Wheel hub, 32d, 33g, 35, 39 Seal member, 33 Wheel hub bearing, 40 Plastic coupling part, 33a, 33b, 43 Outer raceway surface, 33c, 33d, 42a Inner raceway surface, 42b opening, 33e ball, 33f cage, 34, 36a, 36b, 41, 111 rolling bearing, 42 inner ring member, 44 cylindrical roller.

Claims (8)

A motor unit for rotationally driving the motor side rotating member;
A speed reducer that is covered with a casing and that decelerates the rotation of the motor side rotating member and transmits it to the wheel side rotating member;
A wheel hub fixedly connected to the wheel side rotating member;
A deceleration part lubrication mechanism for supplying lubricating oil to the deceleration part,
The speed reducer lubrication mechanism is
A helical lubricating oil passage that is located inside the motor-side rotating member and extends in the direction opposite to the rotation direction of the motor-side rotating member in the direction in which the lubricating oil flows;
A lubricating oil supply port extending from the lubricating oil path toward the outer diameter surface of the motor-side rotating member;
A lubricating oil discharge port for discharging lubricating oil from the speed reduction portion to the casing;
A circulating oil passage connecting the lubricating oil outlet and the lubricating oil passage, and supplying the lubricating oil discharged from the lubricating oil outlet to the lubricating oil passage;
An in-wheel motor drive device comprising: a filtration device that is disposed in the circulation oil passage and filters lubricating oil. The lubricating oil path is
A linear flow path extending linearly along the rotation axis inside the motor side rotation member;
2. The in-wheel motor drive device according to claim 1, further comprising: a spiral groove extending on an outer wall surface of the linear flow channel in a direction opposite to a rotation direction of the motor-side rotation member in a direction in which lubricating oil flows. The lubricating oil path is
A linear flow path extending linearly along the rotation axis inside the motor side rotation member;
The in-wheel motor drive device of Claim 1 with which the winding direction arrange | positioned along the outer wall surface of the said linear flow path contains the coil spring opposite to the rotation direction of the said motor side rotation member. The casing has a lubricating oil reservoir for storing lubricating oil,
The in-wheel motor drive device according to any one of claims 1 to 3, wherein the lubricating oil discharge port is provided on an inner wall surface of the lubricating oil reservoir.   The in-wheel motor drive device according to claim 4, wherein the filter device is a filter cartridge that is detachably attached to the lubricating oil reservoir. The deceleration part is
A revolving member having a through-hole through which the eccentric portion is inserted, and performing a revolving motion around the rotation axis as the motor-side rotating member rotates,
An outer peripheral engaging member fixed to the casing and engaged with an outer peripheral portion of the revolving member to cause a rotation motion of the revolving member;
A motion conversion mechanism that converts the rotational motion of the revolving member into a rotational motion centered on the rotational axis of the motor-side rotating member and transmits the rotational motion to the wheel-side rotating member;
The counterweight which rotates integrally with the said motor side rotation member in the phase which cancels the unbalanced inertia couple by the eccentric motion of the said revolution member in the position adjacent to the said eccentric part is included in any one of Claims 1-5. In-wheel motor drive device. The revolving member has a plurality of corrugations on its outer periphery,
The outer periphery engaging members are a plurality of outer pins including a rolling bearing that is provided at equal intervals on a circumference centered on the rotation axis of the motor side rotating member, and includes a rolling bearing that contacts the outer peripheral portion of the revolution member. The in-wheel motor drive device according to claim 6. The motion conversion mechanism includes an inner pin provided on the wheel side rotation member;
Formed in the revolving member, and having a diameter larger than the outer diameter of the inner pin by a predetermined amount and receiving the inner pin;
The in-wheel motor drive device according to claim 6 or 7, wherein the inner pin includes a rolling bearing that abuts against a wall surface of the hole.

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