JP2011185286A - In-wheel motor driving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a leakage of lubricating oil from a bolt part without forming a threaded hole in a speed reducing part housing itself when locking a wheel hub bearing part to the speed reducing part housing filled with lubricating oil in an in-wheel motor driving device, with a fastening bolt. <P>SOLUTION: The in-wheel motor driving device is adapted to fix the speed reducing part housing 22b and the wheel hub bearing part 33 by inserting the fastening bolt 61 from the wheel hub bearing part 33 side. A box nut 66 to which the tip of the fastening bolt 61 inserted in the speed reducing part housing 22b is screwed is installed in the speed reducing part housing 22b, and an oil leakage preventing mechanism such as an O-ring 68 is provided between the box nut 66 and the speed reducing part housing 22. <P>COPYRIGHT: (C)2011,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 speed reducer.

A conventional in-wheel motor drive device 101 is described in, for example, Japanese Patent Laid-Open No. 2009-216190 (Patent Document 1).
As shown in FIG. 12, the in-wheel motor drive device 101 includes a motor unit 103 that generates a driving force inside a housing 102 that is attached to a vehicle body, a wheel hub bearing unit 104 that is connected to a wheel, and a motor unit 103. And a speed reduction portion 105 that reduces the rotation and transmits the rotation 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. For this reason, a cycloid reducer that is compact and provides a high reduction ratio is often used for the reduction unit 105.

  The speed reduction unit 105 to which the cycloid reduction gear is applied includes a motor side rotation member 106 having eccentric portions 106a and 106b, curved plates 107a and 107b arranged on the eccentric portions 106a and 106b, and curved plates 107a and 107b. A rolling bearing 106c that is rotatably supported with respect to the 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 the curved plates 107a, And a plurality of inner pins 109 for transmitting the rotation motion of 107b to the wheel side rotation member 110.

JP 2009-216190 A

  By the way, in the in-wheel motor drive device 101 having the above-described configuration, 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 rolling bearings 111 are arranged. It is supplied to the raceway surface.

  As shown in FIG. 13, the housing 102 a of the speed reduction unit 105 in which the lubricating oil is sealed is fixed to the flange 104 b of the outer member 104 a of the wheel hub bearing unit 104 by bolts 111.

  The fixing surface between the housing 102a and the flange 104b of the outer member 104a is sealed by an O-ring 112 so that the lubricating oil sealed in the speed reduction unit 105 does not leak to the outside.

  However, as described above, the housing 102a and the flange 104b of the outer member 104a are fixed by cutting the screw hole 102b in the housing 102a and screwing the bolt 111 into the screw hole 102b. Even if the fixing surface of the outer member 104a to the flange 104b is sealed by the O-ring 112, the screw hole 102b of the housing 102a and the screw thread of the bolt 111 as schematically shown by the arrow X in the enlarged view of FIG. There is a risk that the lubricating oil will ooze out from the minute gaps inevitably generated between the two.

  Moreover, the housing 102a of the deceleration part 105 is normally formed with the aluminum alloy for weight reduction. When the screw hole 102b for fastening the bolt 111 is formed in the aluminum alloy housing 102a, it must be set longer than the case of the steel material in terms of strength. There was a problem that the thickness had to be increased and the weight was increased.

In addition, if the screw hole 102b formed in the housing 102a is a bag screw hole in order to prevent the lubricating oil from leaking from the screw hole 102b, the axial length of the housing 102a becomes longer, which also increases the weight. There is.
Further, since the wheel hub bearing portion 104 is a part to be replaced although it is infrequent, it is necessary to retighten the bolt 111 several times at the time of replacement, and the screw hole 102b formed in the aluminum alloy housing 102a There is also a problem in terms of durability.

  Therefore, in the present invention, when the housing 102a of the speed reducing portion 105 and the wheel hub bearing portion 104 sealed with lubricating oil are fastened by the bolt 111, the bolt portion is formed without forming the screw hole 102b in the housing 102a itself. It is an object of the present invention to prevent leakage of lubricating oil from the oil.

  In order to solve the above-described problems, the present invention provides a motor unit that generates a driving force inside a housing that is attached to a vehicle body, a wheel hub bearing unit that is connected to a wheel, and a wheel that decelerates rotation of the motor unit. A wheel hub bearing having a speed reducer portion that transmits to the hub bearing portion, and inserting a tightening bolt into the speed reducer housing from the outer surface side of the wheel hub bearing portion to the speed reducer housing and the wheel hub bearing portion accommodating the speed reducer portion. In the in-wheel motor drive device for fixing the motor and the speed reduction unit housing, a fastening member having a bag screw hole into which a tip of a tightening bolt inserted into the speed reduction unit housing is screwed is installed in the speed reduction unit housing. An oil leakage prevention mechanism is provided between the motor and the speed reduction unit housing.

  The fastening member having the cap screw hole can be constituted by a cap nut.

  The fastening member having the cap screw hole is prevented from rotating in the speed reduction portion housing, so that the fastening work of the fastening bolt can be easily performed.

  In order to prevent the fastening member from rotating, a recess for accommodating the fastening member having the cap screw hole is provided in the speed reducer housing, and the fastening member can be received in the recess to prevent the rotation.

  In addition, by press-fitting the fastening member into the recess provided in the speed reduction part housing, it is possible to prevent the fastening member from rotating and falling into the speed reduction part housing during the tightening operation.

  The oil leakage prevention mechanism between the fastening member and the speed reduction part housing can be constituted by a seal member provided on the facing surface between the fastening member and the speed reduction part housing.

  An O-ring can be used as the sealing member.

  The O-ring can be disposed at an intermediate position between the outer shape of the fastening member facing the inner surface of the speed reduction unit housing and the inner diameter of the cap screw hole.

  Further, the O-ring may be disposed on the outer shape of the fastening member facing the inner surface of the speed reduction unit housing, and assembling is improved by being disposed on the outer shape.

  As the sealing member, a gasket formed of a material such as copper, paper, or resin can be used.

  A cycloid reducer with a high reduction ratio can be used as the reduction unit.

As described above, according to the present invention, the fastening member having the bag screw hole into which the tip of the tightening bolt inserted into the speed reduction portion housing is screwed is installed in the speed reduction portion housing, and the fastening member and the speed reduction portion housing are By providing an oil leakage prevention mechanism between them, oil leakage from around the fastening bolt can be prevented.
Moreover, since it is not necessary to provide the screw hole of the tightening bolt in the speed reduction part housing itself, the thickness of the speed reduction part housing can be reduced and the weight can be reduced.

It is a schematic sectional drawing of the in-wheel motor drive device concerning one Embodiment of this invention. It is an enlarged view of the motor part of FIG. It is an enlarged view of the deceleration part of FIG. It is an enlarged view of the wheel hub bearing part of FIG. It is sectional drawing of the VV line of FIG. It is sectional drawing of the VI-VI line of FIG. It is an enlarged view of the fixed part of the deceleration part housing and wheel hub bearing part which concern on one Embodiment of this invention. It is an enlarged view of the fixing | fixed part of the deceleration part housing and wheel hub bearing part which concern on other embodiment of this invention. It is an enlarged view of the fastening part of the deceleration part housing and wheel hub bearing part which concern on other embodiment of this invention. It is a schematic plan view of the electric vehicle which has the in-wheel motor drive device of FIG. It is the figure seen from the electric vehicle back of FIG. It is a schematic sectional drawing of the conventional in-wheel motor drive device. It is an enlarged view of the fixing | fixed part of the deceleration part housing and wheel hub bearing part in the in-wheel motor drive device of FIG.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
As shown in FIG. 10, an electric vehicle 11 having an in-wheel motor drive device according to an embodiment of the present invention includes a chassis 12, a front wheel 13 as a steering wheel, a rear wheel 14 as a drive wheel, And an in-wheel motor drive device 21 that transmits a driving force to each of the rear wheels 14. As shown in FIG. 11, the rear wheel 14 is housed 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. Further, in order to secure a wider cabin space, the in-wheel motor drive device 21 is required to be smaller and lighter.

  As shown in FIG. 1, the in-wheel motor drive device 21 includes a motor unit A that generates a driving force, a deceleration unit B that decelerates and outputs the rotation of the motor unit A, and an output from the deceleration unit B as driving wheels. 14, the motor hub A and the speed reduction portion B are housed in the motor portion housing 22a and the speed reduction portion housing 22b, and inside the wheel housing 12a of the electric vehicle 11 as shown in FIG. Attached to.

  As shown in FIG. 2, the motor unit A includes a stator 23 fixed to the motor unit housing 22 a, a rotor 24 disposed at a position facing the inner side of the stator 23 with a radial gap therebetween, A radial gap motor including a motor-side rotation member 25 that is fixedly connected to the inside and rotates integrally with the rotor 24. The rotor 24 includes a flange-shaped rotor portion 24a and a cylindrical hollow portion 24b, and is rotatably supported with respect to the motor portion housing 22a by rolling bearings 36a and 36b.

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

As shown in FIG. 3, the speed reducer B is held at fixed positions on the curved plates 26a and 26b as revolving members that are rotatably held by the eccentric portions 25a and 25b, and the curved plate 26a. A plurality of outer pins 27 as outer peripheral engaging members that engage with the outer peripheral portion of 26b, a motion conversion mechanism for transmitting the rotational motion of the curved plates 26a and 26b to the wheel side rotating member 28, and the eccentric portions 25a and 25b. A counterweight 29 is provided at an adjacent position. In addition, the speed reduction part B is provided with a speed reduction part lubrication mechanism that supplies lubricating oil to the speed reduction part B.
The wheel side rotation member 28 includes a flange portion 28a and a shaft portion 28b. Holes for fixing the inner pins 31 are formed on the end face of the flange portion 28a at equal intervals on the circumference around the rotation axis of the wheel side rotation member 28. Further, the shaft portion 28 b is fitted and fixed to the wheel hub 32 and transmits the output of the speed reduction portion B to the wheel 14. The flange portion 28a of the wheel side rotation member 28 and the motor side rotation member 25 are rotatably supported by a rolling bearing 36c.

  As shown in FIG. 6, the curved plates 26 a and 26 b have a plurality of corrugated waves composed of trochoidal curves such as epitrochoids on the outer periphery, and a plurality of through holes 30 a penetrating from one end face to the other end face. Have A plurality of through holes 30a are provided at equal intervals on the circumference centering on the rotation axis of the curved plates 26a, 26b, and receive inner pins 31 described later. Further, the through hole 30b is provided at the center of the curved plates 26a and 26b and is fitted to the eccentric portions 25a and 25b.

  The curved plates 26a and 26b are supported by the rolling bearing 41 so as to be rotatable with respect to the eccentric portions 25a and 25b. The rolling bearing 41 is directly formed on the inner ring member having an inner raceway surface on the outer diameter surface of the eccentric portions 25a and 25b and the inner diameter surface of the through hole 30b of the curved plates 26a and 26b. A cylindrical roller bearing comprising an outer raceway surface, a plurality of cylindrical rollers 44 disposed between the inner raceway surface and the outer raceway surface, and a retainer (not shown) that holds the spacing between adjacent cylindrical rollers 44. .

  The outer pins 27 are provided at equal intervals on a circumferential track centering on the rotation axis of the motor side rotation member 25. When the curved plates 26a and 26b revolve, the curved waveform and the outer pin 27 engage with each other to cause the curved plates 26a and 26b to rotate. Here, the outer pin 27 is rotatably supported with respect to the speed reduction unit housing 22b by a needle roller bearing. Thereby, the contact resistance between the curved plates 26a and 26b can be reduced.

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

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

  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 indicates the outer diameter dimension of the inner pin 31 ("maximum outer diameter including needle roller bearing"). It is set larger by a predetermined amount than the same).

  The speed reduction unit lubrication mechanism supplies lubricating oil to the speed reduction unit B, and includes a lubricating oil passage 26c, a lubricating oil supply port 25d, a lubricating oil discharge port 22c, a lubricating oil storage unit 22d, and a rotary pump 51. And a circulating oil passage 22g.

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

  Further, at least one position of the speed reduction part housing 22b at the position of the speed reduction part B is provided with a lubricating oil discharge port 22c for discharging the lubricating oil inside the speed reduction part B. A circulating oil passage 22g that connects the lubricating oil discharge port 22c and the lubricating oil passage 25c is provided in the motor portion housing 22a. Then, the lubricating oil discharged from the lubricating oil discharge port 22c returns to the lubricating oil path 25c via the circulating oil path 22g.

  Further, the speed reduction unit lubrication mechanism further includes a cooling means for cooling the lubricating oil passing through the circulating oil passage 22g. The cooling means in this embodiment includes a cooling water passage 22e provided in the motor part housing 22b, and the cooling means contributes not only to lubricating oil but also to the cooling of the motor part A.

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

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

  The outer member 33d of the wheel hub bearing 33 is fixed to the speed reduction unit housing 22b by fastening bolts 61.

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

  An annular portion 22f that is in surface contact with the flange portion 33h of the outer member 33d of the wheel hub bearing 32 and is fitted to the cylindrical portion 33i of the outer member 33d is provided on the end surface of the speed reduction portion housing 22b on the wheel hub bearing portion C side. Is provided.

  An annular groove 63 into which the O-ring 62 is fitted is formed on the end surface of the speed reduction portion housing 22b from the outer diameter of the annular portion 22f so as to seal the flange portion 33h of the outer member 33d of the wheel hub bearing 32. ing.

  A plurality of bolt insertion holes 64 through which the fastening bolts 61 are inserted are provided in the flange portion 33h of the outer member 33d of the wheel hub bearing 32 in the circumferential direction.

  In addition, a bolt insertion hole 65 is provided at a position corresponding to the bolt insertion hole 64 of the flange portion 33h of the outer member 33d in the annular portion 22f of the speed reduction portion housing 22b.

  The fastening bolt 61 is inserted from the wheel hub bearing 32 side into the bolt insertion hole 64 of the flange portion 33h of the outer member 33d, and the tip of the fastening bolt 61 is decelerated from the bolt insertion hole 65 of the annular portion 22f of the reduction portion housing 22b. The front end of the protruding fastening bolt 61 is screwed into a cap nut 66 provided on the inner surface of the speed reduction portion housing 22b, and the flange portion 33h of the outer member 33d and the speed reduction portion housing 22b are The annular portion 22f on the end surface is in close contact.

  A recess 67 for receiving the cap nut 66 is provided on the inner surface side of the annular portion 22f at the end surface of the speed reduction portion housing 22b.

  The shape of the recess 67 may be the same as the outer shape of the cap nut 66, or even if it is not the same, as shown in FIG. What is necessary is just the shape which can stop rotation of the cap nut 66 in the state which has the cap nut 66 in the state which has.

  The cap nut 66 is preferably press-fitted into the recess 67. By press-fitting the cap nut 66 into the recess 67, the position of the cap nut 66 in the speed reduction portion housing 22b is determined, and the cap nut 66 is inserted when the fastening bolt 61 is inserted from the flange portion 33h side of the outer member 33d. It is possible to prevent the deceleration part housing 22b from coming out.

  Between the bottom surface of the recess 67 and the end surface of the cap nut 66 that faces the recess 67, as shown in FIG. 7 to FIG. 9, the lubricating oil in the speed reduction part housing 22b is threaded on the fastening bolt 61 and the speed reduction part housing 22b. In order to prevent the lubricating oil from leaking from between the bolt insertion hole 67 and the bolt insertion hole 64 of the flange portion 33h of the outer member 33d, a seal member is disposed.

  7 and 8, the seal member uses an O-ring 68, and in the embodiment shown in FIG. 9, a gasket 69 formed of a material such as copper, paper, or resin is used.

  In the embodiment of FIG. 7, the O-ring 68 is disposed at an intermediate position between the outer shape of the cap nut 66 and the inner diameter of the cap screw hole.

  In the embodiment of FIG. 8, the O-ring 68 is arranged on the outer shape of the cap nut 66. When the O-ring 68 is arranged on the outer shape of the cap nut 66 as in the embodiment of FIG. 8, the O-ring 68 can be easily attached and the assemblability is good.

  In the above embodiment, the cap nut 66 is used. However, the cap nut may be other than the cap nut as long as it is a fastening member having a cap screw hole into which the tip of the tightening bolt 61 inserted into the speed reduction portion housing 22b is screwed.

  As described above, according to the present invention, the tip of the tightening bolt 61 inserted into the speed reduction part housing 22b is screwed into the fastening member having a cap screw hole disposed in the speed reduction part housing 22b, thereby reducing the speed reduction part. The housing 22b and the wheel hub bearing 32 are fixed. Therefore, since the wheel hub bearing 32 can be fixed without forming a screw hole in the speed reduction part housing 22b itself, the thickness of the speed reduction part housing 22b can be reduced, thereby reducing the weight.

  Further, the end face of the fastening member having the cap screw hole is brought into close contact with the inner surface of the speed reduction unit housing 22b via the seal member, so that leakage of the lubricating oil from around the fastening bolt 61 can be prevented.

Hereinafter, the operation principle of the in-wheel motor drive device 21 will be described.
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. Thereby, when the motor side rotation member 25 connected to the rotor 24 rotates, the curved plates 26 a and 26 b revolve around the rotation axis of the motor side rotation member 25. At this time, the outer pin 27 engages with the curved waveform of the curved plates 26 a and 26 b to cause the curved plates 26 a and 26 b to rotate in the direction opposite to the rotation of the motor-side rotating member 25.

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

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

  Note that the reduction ratio of the speed reduction unit B having the above-described configuration is calculated as (ZA−ZB) / ZB, where ZA is the number of outer pins 27 and ZB is the number of waveforms of the curved plates 26a and 26b. In the embodiment shown in FIG. 6, since ZA = 12, ZB = 11, the reduction ratio is 1/11, and a very large reduction ratio can be obtained.

  In this way, by adopting the speed reduction unit B that can obtain a large speed reduction ratio without using a multi-stage configuration, the in-wheel motor drive device 21 having a compact and high speed reduction ratio can be obtained. Further, by providing the needle roller bearings on the outer pin 27 and the inner pin 31, the frictional resistance between the curved plates 26a and 26b is reduced, so that the transmission efficiency of the speed reducing portion B is improved.

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

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

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

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

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

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

  Further, a brake can be added to the configuration of the above embodiment. For example, in the configuration of FIG. 1, the 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 necessary load capacity, a large deep groove ball bearing must be employed. Therefore, from the viewpoint of making the in-wheel motor drive device 21 compact, a cylindrical roller bearing is suitable for the rolling bearing 41.

  In each of the above-described embodiments, an example in which a radial gap motor is adopted as the motor unit A has been described. However, the present invention is not limited to this, and a motor having an arbitrary configuration can be applied. For example, it may be an axial gap motor including a stator fixed to the 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. 10 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 drive vehicle. . In the present specification, “electric vehicle” is a concept including all vehicles that obtain driving force from electric power, and should be understood as including, for example, a hybrid vehicle.

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

DESCRIPTION OF SYMBOLS 11 Electric vehicle 12 Chassis 12a Wheel housing 12b Suspension device 13 Front wheel 14 Rear wheel 22a Housing 22b Reduction part housing 61 Tightening bolt 66 Cap nut 67 Recess 68 O-ring 69 Gasket A Motor part B Reduction part C Wheel hub bearing part

Claims (12)

  A motor unit that generates a driving force inside a housing that is attached to the vehicle body, a wheel hub bearing unit that is connected to the wheel, and a deceleration unit that decelerates the rotation of the motor unit and transmits the reduced speed to the wheel hub bearing unit. In-wheel motor drive for fixing the wheel hub bearing part and the speed reduction part housing by inserting a tightening bolt into the speed reduction part housing from the outer surface side of the wheel hub bearing part. In the apparatus, a fastening member having a cap screw hole into which a tip of a tightening bolt inserted into the speed reduction part housing is screwed is installed in the speed reduction part housing, and an oil leakage prevention mechanism is provided between the fastening member and the speed reduction part housing. An in-wheel motor driving device provided.   2. The in-wheel motor drive device according to claim 1, wherein the fastening member having the cap screw hole is constituted by a cap nut.   The in-wheel motor drive device according to claim 1, wherein the fastening member having the cap screw hole is prevented from rotating in the speed reduction unit housing.   The in-wheel motor according to claim 3, wherein a recess for receiving a fastening member having a cap screw hole is provided in the speed reduction part housing, and the fastening member is prevented from rotating in a state in which the fastening member is received in the recess of the speed reduction part housing. Drive device.   The in-wheel motor drive device of Claim 3 or 4 by which the fastening member is press-fitted in the recess provided in the deceleration part housing.   The oil leakage prevention mechanism is comprised by the sealing member provided in the opposing surface between a fastening member and the housing of a deceleration part between a fastening member and the deceleration part housing. In-wheel motor drive device.   The in-wheel motor drive device according to claim 6, wherein the seal member is an O-ring.   The in-wheel motor drive device according to claim 7, wherein the O-ring is disposed at an intermediate position between the outer shape portion of the fastening member facing the inner surface of the speed reduction portion housing and the inner diameter of the cap screw hole.   The in-wheel motor drive device of Claim 7 which has arrange | positioned the said O-ring in the external shape part of the fastening member facing the inner surface of a deceleration part housing.   The in-wheel motor drive device according to claim 6, wherein the seal member is a gasket.   The in-wheel motor drive device according to any one of claims 1 to 10, wherein the speed reduction unit is a cycloid speed reducer. The in-wheel motor drive device according to any one of claims 1 to 11, wherein the motor unit is a radial gap motor.

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