JP2007238092A - In-wheel motor driving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an in-wheel motor driving device, small-sized, light, and having excellent durability and high reliability. <P>SOLUTION: This in-wheel motor driving device 21 includes: a casing 22; a motor A; a decelerating part B; a wheel hub 32; and a wheel hub bearing 33 for rotatably supporting the wheel hub 32 to the casing 22. The wheel hub bearing 33 includes: an outer member 22a having a first outer raceway surface 33a and a second outer raceway surface 33b on the inside diameter surface; an inner member 38 having a first inner raceway surface 33c opposite to the first outer raceway surface 33a on the outside diameter surface; a wheel hub 32 having a second inner raceway surface 33d opposite to the second outer raceway surface 33b on the outside diameter surface; and a plurality of balls 33e as rolling elements disposed 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, respectively. The wheel hub 32 and the inner member 38 are fixed by diameter-expansion caulking. <P>COPYRIGHT: (C)2007,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 coaxially connected via a reduction gear.

  A conventional in-wheel motor drive device is described in, for example, Japanese Patent Application Laid-Open No. 2001-32914 (Patent Document 1). The in-wheel motor drive device described in the publication includes a motor that generates a driving force, a speed reducer that decelerates the rotation of the motor and transmits it to drive wheels, and a wheel hub that rotatably holds the drive wheels. Prepare.

  As a reduction gear, a planetary gear mechanism comprising a sun gear provided on an input shaft, an internal gear fixed to a casing, and a planetary gear disposed between the sun gear and the internal gear and coupled to an output shaft. Is adopted. Two planetary gear mechanisms are arranged in series to increase the reduction ratio.

  The wheel hub is fixedly connected to the output shaft of the speed reducer and is rotatably supported with respect to the casing by a wheel hub bearing. The wheel hub bearing holds an inner ring fixed to the wheel hub and the output shaft, an outer ring fitted to the inner diameter surface of the casing, a plurality of rolling elements disposed between the inner ring and the outer ring, and a plurality of rolling elements. It is a double row rolling bearing provided with a cage.

In an electric vehicle employing the in-wheel motor drive device configured as described above, it is not necessary to secure a space for the drive unit in the vehicle body, so the effective space in the vehicle increases, and the efficiency decreases and the weight increases due to the transmission system such as a differential device. It is described that it has the advantage of not.
JP 2001-32914 A

  When the in-wheel motor drive device described in the above publication is mounted on an electric vehicle, if a radial load or moment load is applied to the wheel hub due to turning or sudden acceleration / deceleration of the electric vehicle, the wheel hub is eccentric. Or tilt.

  Here, since the output shaft has one end connected to the speed reducer and the other end fixedly connected to the wheel hub, the output shaft also undergoes internal deformation such as eccentricity and inclination as the wheel hub tilts. Produce. This not only hinders the smooth rotation of the planetary gear mechanism, but may cause damage to components due to an excessive load applied between the gears.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an in-wheel motor drive device that is small, light, excellent in durability, and high in reliability.

  The in-wheel motor drive device according to the present invention includes a casing, a motor unit that rotationally drives the motor-side rotation member, a reduction unit that decelerates the rotation of the motor-side rotation member and transmits the rotation to the wheel-side rotation member, and wheel-side rotation. A wheel hub fixedly connected to the member; and a wheel hub bearing that rotatably supports the wheel hub with respect to the casing. The wheel hub bearing includes an outer member having a first outer raceway surface and a second outer raceway surface on an inner diameter surface, an inner member having a first inner raceway surface facing the first outer raceway surface on an outer diameter surface, A wheel hub having a second inner raceway surface facing the second outer raceway surface on the outer diameter surface, between the first outer raceway surface and the first inner raceway surface, and the second outer raceway surface and the second inner raceway surface. And a plurality of rolling elements arranged between each of them. And a wheel hub and an inward member are fixed by diameter expansion caulking.

  By fixedly connecting the inner member and the wheel hub by the above method, the coupling strength can be significantly increased as compared with the case of fixing by fitting. As a result, the wheel hub can be stably held.

  An in-wheel motor drive device according to the present invention includes a casing, a motor unit that rotationally drives the motor-side rotating member, a speed-reducing unit that decelerates the rotation of the motor-side rotating member and transmits the rotation to the wheel-side rotating member, and wheel-side rotation And a wheel hub fixedly connected to the member. The wheel-side rotation member includes a flange portion disposed on the speed reduction portion side and a shaft portion disposed on the wheel hub side, and the flange portion is rotatably supported with respect to the casing by a bearing.

  By setting it as the said structure, it can prevent that a wheel side rotation member inclines with the radial load and moment load which are loaded on a wheel hub. As a result, it is possible to obtain a highly reliable in-wheel motor drive device that maintains the smooth operation of the speed reduction unit.

  Preferably, the in-wheel motor drive device further includes a wheel hub bearing that rotatably supports the wheel hub with respect to the casing, and is provided between the wheel hub bearing and the wheel-side rotating member inserted through the inner diameter surface of the wheel hub bearing. Includes a fitting portion for fixedly connecting the wheel hub bearing and the wheel side rotating member, and a gap portion in which a radial gap is formed between the inner diameter surface of the wheel hub bearing and the outer diameter surface of the wheel side rotating member. And are provided.

  More preferably, the in-wheel motor drive device is provided between a wheel hub bearing that rotatably supports the wheel hub with respect to the casing, and a wheel-side rotating member that is fitted to an inner diameter surface of the wheel hub bearing and the wheel hub bearing. And a joint that transmits the rotation of the wheel side rotation member to the wheel hub while allowing angular displacement and axial displacement.

  Since the above configuration is a structure in which the inclination of the wheel hub is not transmitted to the wheel side rotating member, it is possible to prevent troubles such as defective rotation and damage of the speed reduction unit and obtain a more reliable in-wheel motor drive device. it can. In the present specification, the term “joint” refers to a mechanical element that connects two members to transmit power, or a method thereof.

  As one embodiment, the speed reduction unit is disposed between the sun gear and the internal gear, and is rotatably held by the sun gear provided on the motor-side rotation member, the internal gear fixed to the casing, and the wheel-side rotation member. A plurality of planetary gears.

  As another embodiment, the motor side rotation member further includes an eccentric portion, and the speed reduction portion is rotatably held by the eccentric portion, and revolves around the rotation axis as the motor side rotation member rotates. The revolving member that performs the movement, the outer peripheral engagement member that engages with the outer peripheral portion of the revolving member to cause the revolving member to rotate, and the revolving member that revolves around the rotation axis of the motor side rotating member. A motion converting mechanism that converts the rotational motion into a wheel-side rotating member.

  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.

  According to the present invention, it is possible to obtain an in-wheel motor drive device capable of transmitting sufficient torque to the drive wheels even when a low torque motor is employed. In addition, by adopting a structure that can prevent the wheel-side rotating member from tilting with the tilt of the wheel hub, troubles such as rotation failure and breakage of the speed reduction unit are prevented, and durability is excellent and reliability is high. An in-wheel motor drive device can be obtained.

  With reference to FIG. 4 and FIG. 5, the electric vehicle 11 provided with the in-wheel motor drive device which concerns on one Embodiment of this invention is demonstrated. 4 is a plan view of the electric vehicle 11, and FIG. 5 is a view of the electric vehicle 11 as viewed 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. 15. 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 15 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 15 is required to be reduced in size 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.

  With reference to FIGS. 1-3, the in-wheel motor drive device 21 which concerns on one Embodiment of this invention is demonstrated. 1 is a schematic cross-sectional view of the in-wheel motor drive device 21, FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1, and FIG. 3 is an enlarged view around the eccentric portions 25a and 25b in FIG.

  First, referring to FIG. 1, an in-wheel motor drive device 21 includes a motor unit A that generates a driving force, a deceleration unit B that decelerates and outputs the rotation of the motor unit A, and an output from the deceleration unit B. A wheel hub bearing portion C for transmitting to the drive wheel 14 is provided, and the motor portion A and the speed reduction portion B are accommodated in the casing 22 and attached to the wheel housing 12a of the electric vehicle 11 as shown in FIG.

  The motor unit 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 an axial clearance, and a rotor 24 fixedly connected to the inner side of the rotor 24. It is an axial gap motor provided with the motor side rotation member 25 which rotates integrally. Further, a sealing member (not shown) is provided on the end surface of the motor part A opposite to the speed reduction part B in order to prevent dust from entering the motor part A.

  The rotor 24 includes a flange-shaped rotor portion 24a and a cylindrical hollow portion 24b, and is rotatably supported with respect to the casing 22 by rolling bearings 34a and 34b. 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.

  The wheel side rotation member 28 includes a flange portion 28a and a shaft portion 28b. The end surface of the flange portion 28a has holes for fixing the inner pins 31 at equal intervals on the circumference around the rotation axis of the wheel side rotation member 28, and the outer diameter surface of the hollow portion 28b is a wheel hub bearing. The inner diameter surface of 33 is fitted.

  A double-row angular ball bearing 37 is disposed on the outer diameter surface of the flange portion 28 a to support the wheel-side rotating member 28 so as to be rotatable with respect to the casing 22. Thereby, compared with the case where the wheel side rotation member 28 is connected only to the speed reduction part B and the wheel hub bearing part C, the inclination of the wheel side rotation member 28 accompanying the inclination of the wheel hub 32 can be suppressed. It becomes possible.

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

  The curved plate 26a is rotatably supported by the rolling bearing 39 with respect to the eccentric portion 25a. This rolling bearing 39 is fitted to the eccentric portion 25a, an inner ring 39a having an inner raceway surface on the outer diameter surface, an outer ring 39b fitted to the inner wall surface of the through hole 30b and having an outer raceway surface on the inner diameter surface, It is a deep groove ball bearing provided with balls 39c as a plurality of rolling elements disposed between an inner ring 39a and an outer ring 39b, and a cage (not shown) that holds the plurality of balls 39c.

  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. This coincides with the revolution trajectory of the curved plates 26a and 26b. Therefore, when the curved plates 26a and 26b revolve, the curved waveform and the outer pin 27 engage with each other, and the curved plates 26a and 26b rotate. Cause it to occur. Further, in order to reduce the contact resistance with the curved plates 26a, 26b, a needle roller bearing 27a is provided at a position in contact with the outer peripheral surface of the curved plates 26a, 26b.

  The counterweight 29 has a disc shape and has a through-hole that fits with the motor-side rotating member 25 at a position off the center. Each counterweight 29 is arranged to cancel the couple generated by the rotation of the curved plates 26a and 26b. Arranged on the outside of 25a and 25b with a 180 ° phase change from the eccentric part.

  Here, as shown in FIG. 3, the curved plates 26a and 26b and the counterweight 29 have a center point G between the two curved plates 26a and 26b, and a center point G and the centers of the curved plates 26a and 26b. Is L1, the distance between the center point G and each counterweight 29 is L2, the mass of the curved plate 26a on the right side of the central point G and the weight of the counterweight 29 is m1, the curved plate 46b on the left side of the central point G, and the counterweight. When the mass of 29 is m2 and the eccentric amounts of the center of gravity of the center of gravity are ε1 and ε2, respectively, the relationship satisfies L1 × m1 × ε1 = L2 × m2 × ε2.

  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 rotational axis of the wheel-side rotating member 28, one end is fixed to the wheel-side rotating member 28, and the other end is from a through hole 30 a. A retaining portion 31b is provided to prevent the slipping out. Further, in order to reduce the contact resistance with the curved plates 26a and 26b, needle roller bearings 31a are provided at positions where the curved plates 26a and 26b come into contact with the inner wall surfaces of the through holes 30a. On the other hand, the through hole 30a is provided at a position corresponding to each of the plurality of inner pins 31, and the inner diameter dimension of the through hole 30a is predetermined from the outer diameter dimension of the inner pin 31 (the maximum outer diameter including the needle roller bearing 31a). The minute is set.

  The outer diameter of the inner pin 31 is smaller than the inner diameter of the through hole 30a, and the inner pin 31 and the inner peripheral surface of the through hole 30a rotate while repeating a contact state and a non-contact state. From the viewpoint of smoothly transmitting the rotation to the drive wheel 14, it is desirable to provide a plurality of inner pins 31.

  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 (not shown) 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 inner member 38, 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. Yes. 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 inward member 38 is a substantially cylindrical member having a hollow portion 38a, is fitted into the hollow portion 32a of the wheel hub 32, and receives the shaft portion 28b of the wheel-side rotating member 28 in the hollow portion 38a. The wheel hub 32 and the inward member 38 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 hollow portion 38a of the inner member 38 in a state where the in-wheel motor driving device 21 is fixed. The inner member 38 and the wheel hub 32 are plastically coupled at the plastic coupling portion 40 by being press-fitted into 38a. By fixing and connecting the inner member 38 and the wheel hub 32 by the above method, the coupling strength can be greatly increased as compared with the case of fixing by fitting. Thereby, the wheel hub 32 can be stably held.

  On the other hand, the wheel side rotation member 28 and the inward member 38 are serrated and fitted in the fitting portion 28c. Specifically, the crests extending in the axial direction are arranged at equal intervals in the circumferential direction on the inner diameter surface of the inner member 38, and troughs are formed between the adjacent crests. Similarly, a trough that receives the crest of the inner member 38 and a crest corresponding to the trough of the inner member 38 are formed on the outer diameter surface of the shaft portion 28 b of the wheel-side rotating member 28. And both are fitted so that the peak part of the wheel side rotation member 28 and the peak part of the inward member 38 may mesh.

  With the above configuration, the rotation of the wheel side rotation member 28 can be reliably transmitted to the wheel hub 32. In the gap portion 28d (the right side of the fitting portion 28c in the figure) where the crests and troughs of the wheel side rotation member 28 and the inward member 38 are not formed, the wheel side rotation member 28 and the inward member 38 A gap in the radial direction corresponding to the height of the peak is formed between the two. In this embodiment, the fitting portion 28c is disposed on the wheel hub bearing C side, and the gap portion 28d is disposed on the speed reducing portion B side.

  By securing a predetermined amount of this gap, the inner member 38 does not come into contact with the wheel-side rotating member 28 even if the wheel hub 32 is tilted, and the tilt of the wheel hub 32 is prevented from being transmitted to the wheel-side rotating member 28. Can do. However, if the radial gap formed in the gap 28d is too large, the peaks formed in the wheel-side rotating member 28 and the inward member 38 may be damaged, so that sufficient strength can be secured in the peaks. The gap amount is determined within the range.

  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 constituted by a permanent magnet or a direct current electromagnet 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. At this time, since the inner diameter of the through hole 30a is set larger than the outer diameter of the inner pin 31, the inner pin 31 and the inner wall surface of the through hole 30a are in contact with each other while repeating a contact state and a non-contact state. Exercise. As a result, the revolving motion of the curved plates 26a, 26b is not transmitted to the inner pin 31, and only the rotational motion of the curved plates 26a, 26b is transmitted to the wheel hub bearing portion C via the wheel-side rotating member 28. Since the rotation of the side rotation member 25 is decelerated by the reduction unit B and transmitted to the wheel side rotation member 28, even when the low torque, high rotation type motor unit A is employed, the necessary torque is transmitted to the drive wheels 14. It becomes possible to do.

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, by providing the needle roller bearings 27a and 31a at positions where they contact the curved plates 26a and 26b of the outer pin 27 and the inner pin 31, the contact resistance is reduced, so that the transmission efficiency of the speed reduction portion B is improved. .

  Furthermore, by providing a structure in which the inclination of the wheel hub 32 is not easily transmitted to the wheel-side rotating member 28, it is possible to obtain a highly reliable in-wheel motor drive device 21 that prevents troubles such as rotation failure and breakage of the speed reduction portion B. it can.

  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.

  Since the curved plates 26a and 26b revolve at high speed while engaging with the outer pin 27, a large radial load is applied to the rolling bearing 39 that supports the curved plates 26a and 26b. However, there is a possibility that the rolling bearing 39 having a sufficient load capacity cannot be arranged in a limited space inside the deceleration part B. In addition, this problem becomes more conspicuous with the recent demand for a compact electric vehicle 11.

  Therefore, the outer race 39b can be omitted by providing the outer raceway surface of the rolling bearing 39 on the inner wall surface of the through hole 30b of the curved plates 26a, 26b. As a result, the gap between the inner raceway surface and the outer raceway surface is increased, so that it is possible to employ balls 39c having a large diameter or increase the number of balls 39c. As a result, the load capacity can be improved without changing the overall size of the rolling bearing 39, so that an in-wheel motor drive device having excellent durability and high reliability can be obtained. In addition, it can be expected to reduce the product cost by reducing the number of parts.

  In the above-described embodiment, two curved plates 26a and 26b of the deceleration portion B are provided with 180 ° phase shifts. However, the number of curved plates can be arbitrarily set. For example, three curved plates are provided. In such a case, it is preferable to change the 120 ° phase.

  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 output 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 may be provided in which a movable piston and a cylinder for operating the piston are disposed, and the rotor 24 is locked by fitting the piston and the rotating member when the vehicle is stopped.

  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.

  Moreover, in said embodiment, although the example which employ | adopted the cycloid reduction gear was shown to the deceleration part B, it is possible to apply arbitrary deceleration mechanisms without restricting to this. For example, with reference to FIG. 6, other embodiment of the deceleration part B which the in-wheel motor drive device 21 shown in FIG. 1 employ | adopts is demonstrated. In addition, since the structure of the motor part A and the wheel hub bearing part C is the same, illustration and description are abbreviate | omitted.

  Referring to FIG. 6, the speed reduction unit B ′ is disposed in the casing 41, and reduces the rotation of the motor side rotation member 42 and transmits it to the wheel side rotation member 43. The speed reduction part B ′ is disposed between the sun gear 44 formed on the motor-side rotating member 42, the internal gear 45 formed on the casing 41, the sun gear 44 and the internal gear 45, and attached to the planet carrier shaft 47. A planetary gear mechanism including a plurality of planetary gears 46 rotatably supported by needle roller bearings 48.

  The wheel side rotation member 43 has a flange portion 43 a and a shaft portion 43 b, and the flange portion 43 a has a plurality of holes for receiving the planet carrier shaft 47. Further, the outer diameter surface of the flange portion 43 a is rotatably held with respect to the casing 41 by a double row angular ball bearing 49. The shaft portion 43b is connected to a wheel hub bearing portion C (not shown).

  The operating principle of the deceleration part B ′ having the above configuration will be described.

  First, the sun gear 44 rotates with the rotation of the motor side rotation member 42. At this time, since the planetary gear 46 meshes with both the sun gear 44 and the internal gear 45, the planetary gear 46 rotates in the direction opposite to the rotation direction of the motor side rotation member 42 and is the same as the rotation direction of the motor side rotation member 42. Revolves in the direction.

  The revolving motion of the planetary gear 46 becomes an output of the speed reduction unit B ′ via the planet carrier shaft 47 and is transmitted to the wheel hub bearing unit C. At this time, assuming that the number of teeth of the sun gear 44 is n1 and the number of teeth of the internal gear 45 is n2, the rotation of the motor-side rotating member 42 is decelerated at the reduction ratio r expressed by Equation 1 and the wheel-side rotating member 43 is rotated. Is transmitted to. The reduction ratio r is set to about 1/3 to 1/6 from the viewpoint of gear strength and the like.

  In the above-described embodiment, the example in which the motor-side rotating member 42 and the sun gear 44 are integrally formed has been described. However, the present invention is not limited thereto, and the motor-side rotating member 42 and the sun gear 44 are separately formed. Then, the sun gear 44 may be fixed at a predetermined position of the motor side rotation member 42 by fitting or the like. Similarly, although the example in which the internal gear 45 is directly formed on the inner diameter surface of the casing 41 is shown, the present invention is not limited to this, and the independently formed internal gear 45 may be fitted into the casing 41.

  In the above embodiment, the wheel side rotation member 28 and the inner member 38 are serrated and fitted. However, the present invention is not limited to this, and any connection structure can be applied. . For example, the wheel-side rotating member 28 and the inner member 38 may be spline-fitted, or a joint may be disposed between the wheel-side rotating member 28 and the inner member 38.

  For example, with reference to FIGS. 7 and 8, another embodiment of the connection structure between the wheel-side rotating member 28 and the inner member 38 shown in FIG. 1 will be described. Since the basic configuration is the same as that of the embodiment shown in FIG. 1, illustration and description are omitted, and differences will be mainly described.

  Referring to FIGS. 7 and 8, the inner member 51 and the wheel-side rotating member 52 are slidable to transmit the rotation of the wheel-side rotating member 42 to the wheel hub bearing portion C while allowing angular displacement and axial displacement. They are connected by a dynamic constant velocity universal joint.

  The inner member 51 has a space through which the wheel side rotation member 52 is inserted in the inner diameter surface 51a, and has track grooves 51b extending in the axial direction at four locations. Further, the side wall 51c of the track groove 51b has a curved surface shape.

  The components of the sliding type constant velocity universal joint include a spider 53, an inner roller 54, and an outer roller 55. The spider 53 has a journal 53a that is fitted into the wheel-side rotating member 52 and protrudes radially outward at four locations and is accommodated in the track groove 51b. The inner roller 54 is fitted and fixed to each journal 53a, and the outer diameter surface is a curved surface. The outer roller 55 has a curved outer diameter surface that contacts the side wall 51c of the track groove 51b and a cylindrical inner diameter surface that contacts the outer diameter surface of the inner roller 54. Note that the curvature of the outer diameter surface of the outer roller 55 matches the curvature of the side wall 51c of the track groove 51b.

  In the sliding type constant velocity universal joint configured as described above, the inner roller 54 can be inclined with respect to the outer roller 55, the outer roller 55 can move in the axial direction along the track groove 51b, and the outer roller 55 It can be inclined with respect to the track groove 51b. As a result, the rotation of the wheel-side rotating member 42 is transmitted to the wheel hub bearing portion C while allowing angular displacement and axial displacement between the inner member 51 and the wheel-side rotating member 52. Therefore, it is possible to prevent the inclination of the wheel hub bearing portion C from being transmitted to the wheel side rotation member 52.

  In the above embodiment, the example in which the wheel hub 32 and the inner member 38 are fixedly connected by expanding and caulking is shown. However, the present invention is not limited to this, and the wheel hub 32 and the inner member 38 can be fixedly connected by any method. .

  In the above embodiment, an example in which an angular ball bearing is adopted as the bearings 37 and 49 for supporting the wheel-side rotating members 28 and 43 is shown. However, the present invention is not limited to this, and for example, a plain bearing or a cylindrical roller bearing is used. Roller rollers, tapered roller bearings, needle roller bearings, spherical roller bearings, deep groove ball bearings, angular contact ball bearings, 4-point contact ball bearings, etc., regardless of whether they are plain or rolling bearings. All bearings can be applied regardless of whether they are balls or balls, and whether they are double rows or single rows. Similarly, any type of bearing can be adopted for bearings arranged in other locations.

  In each of the above embodiments, an example in which an axial 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 a radial gap motor including a stator fixed to the casing and a rotor disposed at a position facing the stator with a radial gap inside.

  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 schematic sectional drawing of the in-wheel motor drive device concerning 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 which shows other embodiment of the deceleration part shown in FIG. It is sectional drawing in the direction perpendicular | vertical to the axis | shaft of a sliding type constant velocity universal joint. It is sectional drawing in VIII-VIII of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 Electric vehicle, 12 Chassis, 12a Wheel housing, 12b Suspension device, 13 Front wheel, 14 Rear wheel, 15, 21 In-wheel motor drive device, 22, 41 Casing, 22a Outer member, 23 Stator, 24 Rotor, 24a, 28a 32b, 43a Flange part, 24b, 32a, 38a Hollow part, 28b, 43b Shaft part, 28c Fitting part, 28d Gap part, 25, 42 Motor side rotating member, 25a, 25b Eccentric part, 26a, 26b Curved plate, 27 Outer pin, 27a, 31a, 48 Needle roller bearing, 28, 43, 52 Wheel-side rotating member, 29 Counterweight, 30a, 30b Through hole, 31 Inner pin, 32d, 33g, 34, 36 Sealing member, 33 Wheel Hub bearing, 33a first outer raceway surface, 33b second outer raceway surface, 33c first Inner raceway surface, 33d Second inner raceway surface, 33e, 39c ball, 33f Cage, 34a, 34b, 36a, 36b, 37, 39, 49 Rolling bearing, 39a Inner ring, 39b Outer ring, 38, 51 Inner member, 51a Inner surface, 51b Track groove, 51c Side wall, 40 Plastic coupling part, 44 Sun gear, 45 Internal gear, 46 Planetary gear, 47 Planetary carrier shaft, 48 Needle roller bearing, 53 Spider, 53a Journal, 54 Inner roller, 55 Outside roller.

Claims (2)

A casing,
A motor unit for rotationally driving the motor side rotation member;
A speed reducer 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 wheel hub bearing that rotatably supports the wheel hub with respect to the casing;
The wheel hub bearing is
An outer member having a first outer raceway surface and a second outer raceway surface on an inner diameter surface;
An inner member having a first inner raceway surface facing the first outer raceway surface on an outer diameter surface;
The wheel hub having a second inner raceway surface facing the second outer raceway surface on an outer diameter surface;
A plurality of rolling elements arranged between the first outer raceway surface and the first inner raceway surface, and between the second outer raceway surface and the second inner raceway surface, respectively.
The wheel hub and the inward member are in-wheel motor driving devices that are fixed by diameter expansion caulking. The wheel side rotating member is
Including a flange portion disposed on the speed reduction portion side and a shaft portion disposed on the wheel hub side,
The in-wheel motor drive device according to claim 1, wherein the flange portion is rotatably supported with respect to the casing by a bearing.

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