JP5564608B2 - In-wheel motor drive device - Google Patents

Description

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

A conventional in-wheel motor drive device 101 is described in, for example, Japanese Patent Application Laid-Open No. 2009-52630 (Patent Document 1).
As shown in FIG. 15, the 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. 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 part 105 to which the cycloid reduction gear is applied includes a motor side rotation member 106 having eccentric parts 106a and 106b, curved plates 107a and 107b arranged on the eccentric parts 106a and 106b, and curved side 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.

  The outer pin 108 is not directly held by the casing 102a of the speed reduction unit 105, but is held by an outer pin housing 113 provided on the inner diameter surface of the casing 102a. More specifically, both end portions in the axial direction are rotatably supported by needle roller bearings 114 fixed to the outer pin housing 113. Thus, by making the outer pin 108 rotatable to the outer pin housing 113, the contact resistance due to the engagement with the curved plates 107a and 107b is reduced.

JP 2009-52630 A

  Incidentally, as shown in the enlarged view of FIG. 16, the outer pin housing 113 includes a cylindrical portion 113a and a pair of flange portions 113b and 113b extending radially inward from both axial end portions of the cylindrical portion 113a. The outer pin housing 113 is fitted and fixed to the inner surface of the casing 102a via an elastic member 115. The elastic member 115 has a structure that allows displacement of the outer pin housing 113 in the radial direction and allows displacement in the axial direction. This prevents damage to components such as the curved plates 107a and 107b, the outer pin 108, and the inner pin 109 even when a large radial load or moment load is applied due to turning or sudden acceleration / deceleration of the electric vehicle. Can do. In addition, it is possible to eliminate a hitting sound generated between the casing 102a and the outer pin housing 113 due to vibration during traveling on a rough road.

  However, although the outer pin housing 113 is in a state of floating with respect to the casing 102a by the elastic member 115 in the radial direction, the outer pin housing 113 is constrained by a key or the like in the rotation direction. And vibration may be transmitted to the casing 102a and cause noise.

  Accordingly, an object of the present invention is to provide a quiet in-wheel motor drive device that suppresses the occurrence of vibration between the casing of the speed reduction unit and the housing of the speed reducer housed in the casing of the speed reduction unit.

In order to solve the above-described problems, the present invention provides a motor unit that generates a driving force, a deceleration unit that decelerates and outputs rotation of the motor unit, and a wheel hub bearing that transmits output from the deceleration unit to a wheel. In-wheel motor drive device comprising a casing, a casing for housing the motor unit and the housing of the speed reduction unit, a casing fixing member fixed to the casing between the casing and the housing of the speed reduction unit, and a housing of the speed reduction unit A housing fixing member fixed to the housing is provided, and the casing fixing member and the housing fixing member are bonded to each other with an elastic member interposed therebetween, whereby the housing of the speed reduction portion is held in a floating state with respect to the casing.

  As the elastic member, rubber can be used, and the rubber and the casing fixing member and the housing fixing member may be bonded by an adhesive or by vulcanization bonding.

  The casing fixing member can be constituted by a large-diameter cylindrical portion located on the inner surface of the casing, and a flange provided on one end surface of the large-diameter cylindrical portion. Bolt holes are provided for fixing to the casing.

  Further, the housing fixing member can be constituted by a small-diameter cylindrical portion located on the outer surface of the housing of the speed reduction portion, and a flange provided on one end surface of the small-diameter cylindrical portion. Bolt holes for fixing to the housing of the speed reduction part are provided in the flange.

  Then, the large-diameter cylindrical portion and the small-diameter cylindrical portion are vulcanized and bonded with rubber constituting the elastic member.

  As a result, torque acting on the housing of the speed reduction portion is transmitted from the small diameter cylindrical portion fixed to the housing of the speed reduction portion to the large diameter cylindrical portion via the rubber vulcanized and bonded.

  It is preferable that a bolt with a hexagon socket is used as a bolt to be fixed to the flange of the housing fixing member rather than a hexagon bolt.

  The flange of the casing fixing member is provided with a through hole or a notch at a position corresponding to a hexagon socket head bolt that fixes the housing fixing member to the housing of the speed reduction part, and the hexagonal hole is formed on the inner surface of the through hole or notch. It is preferable to bring the head of the bolt with a hole into contact.

  The head of the hexagon socket head bolt abuts against the inner surface of the through hole or notch, so that the hexagon socket head bolt serves as a stopper in the rotation direction.

  A load is repeatedly applied to the rubber from the housing of the speed reduction unit, and sometimes an impact load is also applied. In order to be able to withstand such a load, if the deformation of the rubber is too great, it will break early, so as described above, the head of the hexagon socket head bolt is applied to the inner surface of the through hole or notch. It is preferable to contact and function as a stopper in the rotation direction.

  Further, as another means for fulfilling the function of the stopper in the rotation direction, a plurality of protrusions are provided on the inner diameter side of the large diameter cylindrical portion located on the inner surface of the casing, and the outer diameter side of the small diameter cylindrical portion is provided. The same number of protrusions may be provided at a distance from the protrusion of the large-diameter cylindrical portion.

  In this case, stoppers can be formed on both sides in the rotation direction, so that it is difficult for the rubber to be twisted and durability is improved.

  As another means of the present invention, a ring plate that is bolted to the casing and a ring plate that is bolted to the housing of the reduction part are sandwiched between the casing facing the axial direction and the housing of the reduction part. A method of vulcanizing and bonding these two ring plates with rubber can also be employed.

  According to this method, since the radial dimension can be reduced, the weight can be reduced.

  The bolt for fixing the ring plate to the housing of the speed reduction part is preferably a hexagon socket head bolt.

  A hole corresponding to the hexagon socket head bolt is provided in a ring plate that is bolted to the housing of the speed reducer, and this hole is arranged so that the hexagon socket head bolt contacts when an excessive torque is applied. It is preferable.

  By forming the hole in the shape of a long hole in the rotation direction, it is possible to maintain the radial thickness of the ring plate.

  Further, the two ring plates vulcanized and bonded by the rubber are sandwiched between the housing of the speed reduction unit and the casing of the motor unit, and one of the two ring plates is fixed to the housing of the speed reduction unit, and the other Can also be fixed to the casing of the motor unit. As a result, the ring plates are arranged on both axial sides of the housing of the speed reducing portion, so that the load capacity is improved.

  The ring plate is more preferably one in which a light metal such as aluminum is used and an iron screw portion is insert-molded for weight reduction. Each of the iron screw portions may be insert-molded as a single product, or it is more preferable to insert-mold one that is fixed to a thin ring plate in advance by welding or the like.

  The rubber used in the present invention is preferably oil-resistant rubber such as nitrile rubber, hydrogenated nitrile rubber, acrylic rubber, and fluorine rubber.

The speed reducer may be a cycloid speed reducer or a planetary gear speed reducer.

  When the speed reducer is a cycloid reducer, the housing of the speed reducer is an outer pin housing of the cycloid reducer.

  On the other hand, when the speed reduction part is a planetary gear speed reducer, the housing of the speed reduction part is an internal gear of the planetary gear speed reducer.

As described above, according to the present invention, the housing of the speed reducer with respect to the casing is held via the casing side fixing member and the housing side fixing member which are bonded to each other with the elastic member interposed therebetween . Even when a large load or moment load is applied to the housing of the reducer due to turning, rapid acceleration / deceleration, etc., the components such as the motion conversion mechanism can be prevented from being damaged.

  In addition, the elastic member can eliminate sound hitting by vibrations generated when traveling on rough roads.

1 is a schematic cross-sectional view of an in-wheel motor drive device according to a first embodiment of the present invention. It is sectional drawing of the II-II line of FIG. It is the side view of the casing fixing member seen from the direction of the III-III line of FIG. (A) is the longitudinal cross-sectional view of the casing fixing member and housing fixing member which were cut | disconnected by the II-II line | wire of FIG. 1, (b) is a right end view of (a) figure. (A) is the longitudinal cross-sectional view of other embodiment of the casing fixing member and housing fixing member cut | disconnected by the II-II line | wire of FIG. 1, (b) is a right end view of (a) figure. It is a schematic sectional drawing of the in-wheel motor drive device which concerns on 2nd Embodiment of this invention. (A) is the side view which looked at the casing fixing member of embodiment of FIG. 6 from the wheel hub bearing part side, (b) is the state which adhere | attached the casing fixing member and housing fixing member of embodiment of FIG. 6 with rubber | gum. (C) is sectional drawing of the VII-VII line of (b) figure. (A) is the side view which looked at the state which inserted the volt | bolt in the casing fixing member of embodiment of FIG. 6 from the wheel hub bearing part side, (b) is the side view which shows the state at the time of the torque of a rotation direction being added. It is. (A) is the side view which looked at the state which inserted the volt | bolt in the other casing fixing member of FIG. 6 embodiment from the wheel hub bearing part side, (b) bonded the casing fixing member and the housing fixing member with rubber | gum. FIG. 6A is a longitudinal sectional view taken along line IXb-IXb in FIG. 5A showing a state, and FIG. 5C is a sectional view taken along line IXc-IXc in FIG. It is a schematic sectional drawing of the in-wheel motor drive device which concerns on 3rd Embodiment of this invention. (A) is the side view which looked at the state which inserted the volt | bolt in the casing fixing member of embodiment of FIG. 10 from the wheel hub bearing part side, (b) is the state which adhere | attached the casing fixing member and the housing fixing member with rubber | gum. The longitudinal cross-sectional view of the XIb-XIb line | wire of (a) shown, (c) is sectional drawing of XIc-XIc of (b) figure. It is a longitudinal cross-sectional view of the other casing fixing member of embodiment of FIG. It is a schematic plan view of the electric vehicle which has an in-wheel motor drive device. 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 which shows the fixed state of the casing of the deceleration part of FIG. 15, and the housing of a reduction gear.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
As shown in FIG. 13, 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. 14, the rear wheel 14 is accommodated in a wheel housing 12a of the chassis 12, and is fixed to the lower portion of the chassis 12 via a suspension device (suspension) 12b.

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

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

  On the other hand, in order to improve the running stability of the electric vehicle 11, it is necessary to suppress the unsprung weight. Further, in order to secure a wider cabin space, the in-wheel motor drive device 21 is required to be smaller and lighter.

1 to 5 show an in-wheel motor drive device 21 according to an embodiment of the present invention.
As shown in FIG. 1, the in-wheel motor drive device 21 drives 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 wheel 14 is provided. The motor portion A and the speed reduction portion B are accommodated in the motor portion casing 22a and the speed reduction portion casing 22b, and as shown in FIG. 13, the wheel housing 12a of the electric vehicle 11 is provided. Installed inside. The motor part casing 22a and the speed reduction part casing 22b are integrated by a bolt 80.

The motor part A includes a stator 23 fixed to the motor part casing 22 a, a rotor 24 disposed at a position facing the inner side of the stator 23 with an axial gap therebetween, and a rotor 24 fixedly connected to the inner side of the rotor 24. 24 is an axial gap motor including a motor-side rotation member 25 that rotates integrally with the motor 24. 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 24a and a cylindrical hollow portion 24b, and is supported by a rolling bearing 34 so as to be rotatable with respect to the motor portion casing 22a. Further, a sealing member 35 is provided between the motor unit casing 22a and the rotor 24 in order to prevent the lubricant encapsulated in the speed reduction unit B from entering the motor unit A.

  The motor side rotation member 25 is arranged from the motor part A to the speed reduction part B in order to transmit the driving force of the motor part A to the speed reduction part B, and has eccentric parts 25a and 25b in the speed reduction part B. One end of the motor-side rotating member 25 is fitted to the rotor 24, and is supported by 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 so as to cancel out vibrations generated by the centrifugal force due to the eccentric motion.

  The deceleration part B includes curved plates 26a and 26b as revolving members that are rotatably held by the eccentric parts 25a and 25b, and a plurality of outer pins as outer peripheral engaging members that engage with the outer peripheral parts of the curved plates 26a and 26b. 27 and a motion conversion mechanism for transmitting the rotational motion of the curved plates 26a and 26b to the wheel side rotation member 28.

  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. A first inner raceway surface 33c of the wheel hub bearing 33 is formed on the outer diameter surface of the shaft portion 28b.

  As shown in FIG. 2, the curved plates 26 a and 26 b have a plurality of corrugations 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. , 30b. A plurality of through holes 30a and 30b are provided at equal intervals on the circumference centering on the rotation axis of the curved plates 26a and 26b, and receive an inner pin 31 described later. Further, the through hole 30c is provided at the center of the curved plates 26a and 26b and is fitted to the eccentric portions 25a and 25b.

  The curved plate 26a is rotatably supported by the rolling bearing 41 with respect to the eccentric portion 25a. The rolling bearing 41 is fitted to the outer diameter surface of the eccentric portion 25a, and is fitted to the inner ring member 42 having the inner raceway surface 42a on the outer diameter surface and the inner diameter surface of the through hole 30c of the curved plate 26a. An outer raceway surface 43a is provided on the inner diameter surface. The cylindrical roller bearing includes a plurality of cylindrical rollers 44 disposed between the inner raceway surface 42a and the outer raceway surface 43a, and a retainer (not shown) that holds the interval between the 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.

  The outer pin 27 is not directly held by the speed reduction unit casing 22b, but is held by an outer pin housing 45 constituting a housing of a reduction gear fixed to the inner diameter surface of the speed reduction unit casing 22b. More specifically, a casing fixing member 51 fixed to the inner surface of the speed reduction unit casing 22b and the outer surface of the outer pin housing 45 between the speed reduction unit casing 22b and the outer pin housing 45 constituting the speed reducer housing. A housing fixing member 52 to be fixed is provided, and the casing fixing member 51 and the housing fixing member 52 are prevented from rotating through a rubber 53 which is an elastic member.

  The outer pin 27 is rotatably supported by needle roller bearings 27 a fixed at both ends in the axial direction to the outer pin housing 45. Thus, by making the outer pin 27 rotatable to the outer pin housing 45, the contact resistance due to the engagement with the curved plates 26a and 26b can be reduced.

  The rubber 53, the casing fixing member 51, and the housing fixing member 52 may be bonded by an adhesive or a vulcanized bond.

  As shown in FIG. 4, the casing fixing member 51 includes a large-diameter cylindrical portion 51a located on the inner surface of the speed reduction portion casing 22b and a flange 51b provided on one end surface of the large-diameter cylindrical portion 51a. The flange 51b of the casing fixing member 51 is provided with a bolt hole 54 for fixing to the casing 22b.

  The housing fixing member 52 can be constituted by a small diameter cylindrical portion 52a located on the outer surface of the outer pin housing 45 and a flange 52b provided on one end surface of the small diameter cylindrical portion 52a. Bolt holes 55 for fixing to the outer pin housing 45 are provided in the flange 52 b of the housing fixing member 52.

  The large-diameter cylindrical portion 51a and the small-diameter cylindrical portion 52a are vulcanized and bonded by the rubber 53 constituting the elastic member.

  Thereby, torque acting on the outer pin housing 45 is transmitted from the small diameter cylindrical portion 52a fixed to the outer pin housing 45 to the large diameter cylindrical portion 51a via the rubber 53 vulcanized and bonded.

  The bolt 56 fixed to the flange 52b of the housing fixing member 52 is not a hexagon bolt but a hexagon socket head bolt.

  The flange 51 b of the casing fixing member 51 is provided with a notch 57 at a position corresponding to the bolt 56 for fixing the housing fixing member 52 to the outer pin housing 45, and between the notch 57 and the bolt 56. As shown in FIG. 3, the clearance a is provided, but when a rotational load is applied to the outer pin housing 45, the inner surface of the notch 57 and the head of the bolt 56 come into contact with each other in the rotational direction. It plays a role as a stopper.

  The notch 57 may be a through hole.

  A load is repeatedly applied to the rubber 53 from the outer pin housing 45, and sometimes an impact load is also applied. In order to be able to withstand such a load, if the deformation of the rubber 53 is too great, it will break early, so that the head of the bolt 56 will contact the notch 57 or the inner surface of the through hole as described above. The contact is made to function as a stopper in the rotation direction.

  Further, as another means for fulfilling the function of the stopper in the rotation direction, as shown in FIG. 5, a plurality of protrusions 58 are provided on the inner diameter side of the large-diameter cylindrical portion 51a located on the inner surface of the casing 22b. The same number of protrusions 59 may be provided on the outer diameter side of the small-diameter cylindrical part 52b at a distance from the protrusions 58 of the large-diameter cylindrical part 51a.

  In this case, stoppers can be formed on both sides in the rotation direction, so that the rubber 53 is less likely to be twisted and durability is further improved.

  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 speed reduction portion casing 22b. 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 cage 33f that holds the balls 33e in the left and right rows, 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 outer member 33h of the wheel hub bearing 33 is fixed to the speed reducer casing 22b by fastening bolts 61.

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

  Further, the casing 22b of the speed reduction part B is provided with a bolt insertion hole 65 of a fastening bolt 61 inserted into the bolt insertion hole 64 of the flange part of the outer member 33h.

  Further, a bolt hole 66 of a fastening bolt 61 is provided in the flange 51 b of the casing fixing member 51.

  The fastening bolt 61 is inserted from the wheel hub bearing 32 side into the bolt insertion hole 64 of the flange portion of the outer member 33h, and the tip of the fastening bolt 61 is inserted into the bolt hole 65 of the speed reduction portion casing 22b. The casing fixing member 51 is fixed to the speed reduction part casing 22b by screwing into the bolt hole 66 of the fixing member 51.

  Next, a second embodiment of the present invention in which the means for fixing the outer pin housing 45 to the speed reducer casing 22b is different will be described with reference to FIGS.

  Since the configurations of the motor unit A, the speed reduction unit B, and the wheel hub bearing unit C are basically the same as those of the first embodiment, these configurations are denoted by the same reference numerals and detailed description thereof is omitted.

  In this second embodiment, the speed reducer casing 22b and the outer pin housing 45 constituting the speed reducer housing are bolted to the speed reducer casing 22b at the portion facing the end face on the wheel hub bearing portion C side in the axial direction. A ring plate 71 fixed by 61 and a ring plate 72 fixed by a bolt 56 to the outer pin housing 45 are sandwiched, and the two ring plates 71 and 72 are vulcanized and bonded by a rubber 53.

  According to the second embodiment, since the radial dimension can be reduced, the weight can be reduced.

  As the bolt 56 for fixing the ring plate 72 to the outer pin housing 45, it is preferable to use a hexagon socket head cap bolt as in the first embodiment.

  As shown in FIG. 7A, a hole 73 corresponding to the bolt 56 is provided in the ring plate 71 fixed to the speed reduction unit casing 22b by the bolt 61.

  As shown in FIG. 8A, the hole 73 is formed in such a size that a gap a is opened between the head of the bolt 56 and the inner surface of the hole 73 in a state where the bolt 56 is inserted. When an excessive torque is applied due to the gap a, the inner surface of the hole 73 and the head of the bolt 56 come into contact with each other to serve as a stopper, as shown in FIG. 8B.

  The holes 73 are preferably arranged so that the heads of the bolts 56 with hexagonal holes come into contact when excessive torque is applied.

  The hole 73 may be formed in a long hole shape in the rotation direction as shown in FIG. Thereby, the radial thickness of the ring plate 71 can be minimized.

  Next, a third embodiment of the present invention in which the means for fixing the outer pin housing 45 to the casing 22b of the speed reducer B is different will be described with reference to FIGS.

  Since the configurations of the motor unit A, the speed reduction unit B, and the wheel hub bearing unit C are basically the same as those of the first embodiment, these configurations are denoted by the same reference numerals and detailed description thereof is omitted.

The third embodiment is an example in which the ring plate 71 and the ring plate 72 of the second embodiment are provided not only on the wheel hub bearing portion C side in the axial direction but also on the motor portion A side.
That is, in this example, the ring plate 71 and the ring plate 72 are provided on both sides in the axial direction of the outer pin housing 45 to improve the load capacity.

  In this example, the ring plate 71 on the motor part A side is fixed to the motor part casing 22a with bolts 56.

  As shown in FIG. 11A, the ring plate 71 is provided with holes 73 corresponding to the bolts 56. The hole 73 is formed in a long hole shape in the rotation direction.

  A ring plate 71 shown in FIG. 11 uses a light metal such as aluminum and insert-molds an iron screw portion 74 for weight reduction.

  FIG. 12 shows an example in which an iron screw portion 74 is previously fixed to a thin ring plate 71 by welding or the like, and insert molding is performed.

  The rubber used in the present invention is preferably oil-resistant rubber such as nitrile rubber, hydrogenated nitrile rubber, acrylic rubber, and fluorine rubber.

  Although the said 1st-3rd embodiment showed the example which used the cycloid reducer as the deceleration part B, the planetary gear reducer may be sufficient as a reducer. When a planetary gear speed reducer is used as the speed reducer, the internal gear of the planetary gear speed reducer constitutes the housing of the speed reducing portion in the present invention.

  In the first to third embodiments, the outer pin housing 45 is always held at a predetermined position by the restoring force of the rubber 53 so that the positional relationship between the speed reduction portion B and the casing 22b is correctly maintained.

  Further, even when a large load or moment load is applied due to turning or rapid acceleration / deceleration, damage to components such as the revolution member, the outer peripheral engagement member, and the motion conversion mechanism is prevented.

  Further, the sound generated between the casing 22b and the outer pin housing 45 due to the axial vibration generated when traveling on a rough road or the like is eliminated.

The operation principle of the in-wheel motor drive device 21 having the above configuration will be described in detail.

  The motor unit A receives, for example, an electromagnetic force generated by supplying an alternating current to the coil of the stator 23, and the rotor 24 composed of a permanent magnet or a magnetic material rotates. At this time, the rotor 24 rotates at a higher speed as a higher frequency voltage is applied to the coil.

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

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

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

  Note that the reduction ratio of the speed reduction unit B having the above-described configuration is calculated as (ZA−ZB) / ZB, where ZA is the number of outer pins 27 and ZB is the number of waveforms of the curved plates 26a and 26b. In the embodiment shown in FIG. 2, 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, since the outer pin 27 is rotatable with respect to the outer pin holding portion 45 and the needle roller bearing 31a is provided at a position where the outer pin 27 contacts the curved plates 26a and 26b of the inner pin 31, the frictional resistance is reduced. The transmission efficiency of the deceleration part B is improved.

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

  In the above embodiment, the 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.

  In the above embodiment, an example of a cylindrical roller bearing has been shown as a bearing for supporting the curved plates 26a and 26b. However, the present invention is not limited to this example. Bearings, spherical roller bearings, angular contact ball bearings, 4-point contact ball bearings, etc., whether they are plain bearings or rolling bearings, regardless of whether the rolling elements are rollers or balls, All bearings can be applied, whether double row or single row. 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. 13 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 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 22 Housing 22a Motor part casing 22b Deceleration part housing 23 Stator 24 Rotor 25 Motor side rotating member 25a, 25b Eccentric part 26a, 26b Curved plate 27 Outer pin 28 Wheel Side rotation member 45 Outer pin housing 50 Presser plate 51 Casing fixing member 51a Cylindrical portion 51b Flange 52 Housing fixing member 52a Cylindrical portion 52b Flange 53 Rubber 54 Bolt hole 56 Bolt 57 Notch portion 58, 59 Projection 61 Bolt 66 Bolt hole 71, 72 Ring plate 73 Hole 74 Iron thread

Claims (3)

  A motor unit that generates a driving force, a deceleration unit that decelerates and outputs the rotation of the motor unit, a wheel hub bearing unit that transmits output from the deceleration unit to wheels, and a housing for the motor unit and the reduction unit are accommodated. In an in-wheel motor drive device provided with a casing, a casing fixing member fixed to a casing and a housing fixing member fixed to a housing of a reduction part are provided between the casing and a housing of a reduction part, and a casing fixing member An in-wheel motor drive device characterized in that the housing of the speed reduction unit is held in a floating state with respect to the casing by bonding the housing fixing member and the housing fixing member with the elastic member interposed therebetween.   The in-wheel motor drive device according to claim 1, wherein a casing side fixing member and a housing side fixing member bonded with the elastic member interposed therebetween are provided on both sides in the axial direction of the housing.   The in-wheel motor drive device according to claim 1, wherein the elastic member is rubber and is vulcanized and bonded to the casing side fixing member and the housing side fixing member.

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