JP2015093492A - In-wheel motor driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain firm fastening power between an outer pin housing shaft part 73 and a fixation hole 74 of an outer pin housing 50 of a cycloid type deceleration part 20 even when length of the outer pin housing side shaft part 73 of a floating pin 71 for fixing the outer pin housing 50 to a casing 11 is shortened.SOLUTION: An outer pin housing side shaft part 73 and a fixation hole 74 of an outer pin housing 50 are integrated by providing an outer peripheral surface of the outer pin housing side fixation shaft part 73 of a floating pin 71 with a projection 76 extending in an axial direction, and engaging the projection 76 along the axial direction into an inner diameter surface of the fixation hole 74 of the outer pin housing 50.

Description

  The present invention relates to an in-wheel motor drive device for driving drive wheels of an automobile.

  As shown in FIG. 16, the in-wheel motor drive device includes a motor unit 110 that generates a driving force, a speed reduction unit 120 that decelerates and outputs the rotation of the motor unit 110, and an output from the speed reduction unit 120 as drive wheels. A transmission wheel hub 130.

  Since the in-wheel motor drive device is installed inside the wheel, downsizing is required. Further, a large rotational drive torque is required to drive the drive wheels.

  In order to meet these demands, the in-wheel motor drive device described in Patent Document 1 employs a cycloid reduction gear for the speed reduction section 120 that reduces the rotation of the motor section 110.

  As shown in FIG. 16 and FIG. 17, the cycloid reduction gear is formed on the outer periphery of the curved plate 124 by rotatably supporting the curved plate 124 by an eccentric shaft portion 123 provided on the input shaft 122. The corrugated tooth shape meshes with the outer pin 125 supported on the inner side of the outer pin housing 150 located on the inner diameter surface of the casing 111 of the speed reduction unit 120 via a gap, and the curved plate 124 is eccentrically swung by the rotation of the input shaft 122. The wheel hub 130 is rotated by outputting the rotation of the curved plate 124 from the output shaft 126 disposed coaxially with the input shaft 122.

  The outer pin housing 150 is floatingly supported by floating pins 159 from both ends in the axial direction with respect to the casing 111 of the speed reduction unit 120.

  Fixing holes 160 for press-fitting the floating pins 159 are arranged at equal intervals on the side surfaces of both ends in the axial direction of the outer pin housing 150, and the outer pin housing side shaft portion 159 a of the floating pins 159 is inserted into the fixing holes 160. The outer pin housing 150 is fixed with respect to the casing 111 of the speed reduction unit 120 by press-fitting.

JP 2009-63043 A

  By the way, since the fixing hole 160 of the outer pin housing 150 and the outer pin housing side shaft portion 159a of the floating pin 159 are fixed by press-fitting or screw fastening, a certain length of press-fitting allowance is necessary to secure the fastening force. is there.

  If the length of the outer pin housing side shaft portion 159a that is press-fitted into the fixing hole 160 of the outer pin housing 150 is increased, the entire length of the floating pin 159 must be naturally increased, and there is room for improvement in terms of miniaturization and weight reduction. There is.

In order to obtain a strong fastening force between the outer pin housing side shaft portion 159a of the floating pin 159 and the fixing hole 160 of the outer pin housing 150, the outer surface of the outer pin housing side shaft portion 159a of the floating pin 159 is There was also a problem that polishing had to be performed, and the cost of polishing increased.
Further, in the case of screw fastening, there is a problem that the screw processing must be performed on the outer pin housing side and the floating pin, and the cycle time for fastening is long and the cost is increased.

  Therefore, even if the length of the outer pin housing side shaft portion 159a of the floating pin 159 is shortened, a strong fastening force can be obtained with the fixing hole 160 of the outer pin housing 150, thereby reducing the size. The object is to reduce the weight and reduce the processing cost of polishing.

  In order to solve the above problems, in the present invention, a motor unit that generates a driving force, a reduction unit that decelerates and outputs the rotation of the motor unit, and a wheel hub that transmits the output from the reduction unit to the drive wheels. A curved plate that is rotatably supported by an eccentric shaft provided on the input shaft, and a waveform formed on the inner surface of the casing of the deceleration unit via a gap and formed on the outer periphery of the curved plate An outer pin housing that supports an outer pin that meshes with the tooth profile, and the outer pin housing side fixed shaft portion of the floating pin fixed to the casing is inserted into the fixing holes at both ends of the outer pin housing in the axial direction. Is supported in a floating manner with respect to the casing, and the curved plate is eccentrically swung by the rotation of the input shaft of the speed reducer, and the rotation of the curved plate is output from the output shaft arranged coaxially with the input shaft. In the in-wheel motor drive device that rotates the wheel hub, a plurality of convex portions extending in the axial direction are provided on the outer peripheral surface of the outer pin housing side fixed shaft portion of the floating pin, and the plurality of convex portions are provided on the outer pin housing. It is characterized in that the outer pin housing side shaft portion and the fixing hole of the outer pin housing are integrated with each other by biting into the inner diameter surface of the fixing hole along the axial direction.

  The convex portion extending in the axial direction on the outer peripheral surface of the outer pin housing side fixed shaft portion of the floating pin can be formed by rolling.

  In order to cause the protruding portion extending in the axial direction to the outer peripheral surface of the fixed pin portion on the outer pin housing side of the floating pin to bite into the inner diameter surface of the fixing hole of the outer pin housing along the axial direction, the floating pin is heat-treated, The pin housing is not heat-treated, or steel material having a low hardness relative to the floating pin is used.

  In contrast to the convex portion extending in the axial direction on the outer peripheral surface of the outer pin housing side fixed shaft portion of the floating pin, a concave portion having a tightening margin may be formed in advance on the inner diameter surface of the fixing hole of the outer pin housing.

  In the in-wheel motor drive device according to the present invention, as described above, a convex portion extending in the axial direction is provided on the outer peripheral surface of the outer pin housing side fixed shaft portion of the floating pin, and the convex portion is fixed to the fixing hole of the outer pin housing. Since the outer pin housing side shaft and the fixing hole of the outer pin housing are integrated into the inner diameter surface of the pin, the floating pin is firmly fixed to the outer pin housing rather than simple press-fitting. be able to.

  Therefore, the press-fitting length of the floating pin can be shortened, and the size and cost are reduced.

  Also, compared to a simple press-fitting type, polishing of the floating pin can be omitted, and the cost is reduced.

  Since the convex part of the floating pin bites into the outer pin housing, there is no shift in the rotational direction of the floating pin, and peeling wear that occurs between the floating pin and the outer pin housing is less likely to occur compared to a simple press-fitting type.

  Further, since the convex part of the floating pin bites in while cutting the outer pin housing, the deformation of the outer pin housing is small, and the position and accuracy after press-fitting are better than simple press-fitting.

It is a schematic plan view of the electric vehicle carrying an in-wheel motor drive device. It is the schematic which shows the state which mounted the in-wheel motor drive device in the wheel house. It is a longitudinal cross-sectional view which shows embodiment of an in-wheel motor drive device. It is an enlarged view of the deceleration part of the in-wheel motor drive device of FIG. It is sectional drawing along the VV line of FIG. It is a longitudinal cross-sectional view which shows the fixed state of an outer pin housing and a floating pin. The floating pin used in this invention is shown, (a) is a side view, (b) is a front view seen from the direction of the outer pin housing side shaft portion. FIG. 7 is an enlarged view of a portion indicated by a circle A in FIG. 6 showing a state in the middle of inserting the outer pin housing side shaft portion of the floating pin into the fixing hole of the outer pin housing. FIG. 7 is an enlarged view of a portion indicated by a circle A in FIG. 6 showing a state in which the outer pin housing side shaft portion of the floating pin is completely pressed into the fixing hole of the outer pin housing. It is sectional drawing which shows the state which press-fitted the outer pin housing side axial part of the floating pin with respect to the fixing hole of the outer pin housing. It is a partial expanded sectional view which shows the state which press-fitted the outer pin housing side axial part of the floating pin with respect to the fixing hole of the outer pin housing. It is a partial expanded sectional view of other embodiment which shows the state which press-fitted the outer pin housing side axial part of the floating pin with respect to the fixing hole of the outer pin housing. It is a partial expanded sectional view of other embodiment which shows the state which press-fitted the outer pin housing side axial part of the floating pin with respect to the fixing hole of the outer pin housing. It is a partial expanded sectional view of other embodiment which shows the state which press-fitted the outer pin housing side axial part of the floating pin with respect to the fixing hole of the outer pin housing. It is a partial expanded sectional view of other embodiment which shows the state which press-fitted the outer pin housing side axial part of the floating pin with respect to the fixing hole of the outer pin housing. It is a longitudinal cross-sectional view which shows the conventional in-wheel motor drive device. It is an expanded longitudinal cross-sectional view of the deceleration part of the conventional in-wheel motor drive device.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
As shown in FIG. 1, an electric vehicle 1 including an in-wheel motor drive device according to an embodiment of the present invention includes a chassis 2, front wheels 3 as steering wheels, drive wheels 4 (rear wheels), left and right The in-wheel motor drive device A which transmits a driving force to each of the drive wheels 4 is provided. As shown in FIG. 2, the drive wheels 4 are accommodated inside a wheel house 2 a of the chassis 2 and supported by the chassis 2 via a suspension device (suspension) 5. As a mounting form of the in-wheel motor drive device A, any of the front wheel drive system and the four wheel drive system may be used in addition to the rear wheel drive system shown in FIG.

  The suspension device 5 supports the driving wheel 4 by a suspension arm 5a extending from side to side, and absorbs vibration received from the ground by the driving wheel 4 from the ground by a strut 5b including a coil spring and a shock absorber. Transmission is suppressed. The suspension device 5 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 road surface irregularities and efficiently transmit the driving force of the drive wheels 4 to the road surface. desirable.

  The electric vehicle 1 needs to provide a motor, a drive shaft, a differential gear mechanism, and the like on the chassis 2 by housing the in-wheel motor drive device A that drives the left and right drive wheels 4 in the wheel house 2a. Therefore, it is possible to secure a wide cabin space and control the rotation of the left and right drive wheels.

  As shown in FIG. 3, the in-wheel motor drive device A includes a motor unit 10 that generates a driving force, a deceleration unit 20 that decelerates and outputs the rotation of the motor unit 10, and an output from the deceleration unit 20 as driving wheels. 4 and a wheel hub 30 to be transmitted to the vehicle.

  The motor unit 10 and the speed reduction unit 20 are accommodated in the casing 11. The casing 11 includes a casing 11a on the motor unit 10 side and a casing 11b on the speed reduction unit 20 side, and a penetration portion through which the motor rotating shaft 14 of the motor unit 10 is inserted is formed at the center of the casing 11a on the motor unit 10 side. Has been.

  The motor unit 10 is of a radial gap type in which a stator 12 is provided on the inner peripheral surface of the casing 11a, and a rotor 13 is provided at an interval on the inner periphery of the stator 12.

  The rotor 13 has a motor rotating shaft 14 at the center, and the motor rotating shaft 14 is supported by bearings 15 and 15 so as to be rotatable with respect to the casing 11a. The motor rotation shaft 14 is inserted into the casing 11 b of the speed reduction unit 20 and is connected to the input shaft 22 of the speed reduction unit 20.

  The speed reduction unit 20 is accommodated in the casing 11 b and has an input shaft 22 and an output shaft 26 connected to the motor rotation shaft 14, and the rotation of the input shaft 22 is decelerated and transmitted to the output shaft 26.

  The wheel hub 30 is fixedly connected to the output shaft 26 of the speed reduction unit 20 and is rotatably supported by the casing 11.

  The casing 11 is provided with a lubricating oil pump 61 that discharges lubricating oil. The casing 11 is provided with an oil passage 43 of the lubricating oil pump 61, the oil passage 43, a motor rotation shaft oil passage 44 provided on the motor rotation shaft 14, and a speed reducer input shaft oil passage provided on the input shaft 22. 45 are mutually connected, and the lubricating oil discharged from the lubricating oil pump 61 is supplied to the oil passage 43 provided in the casing 11, the motor rotation shaft oil passage 44, the speed reduction portion input shaft oil passage 45, and the inside of the speed reduction portion 20. The lubricating oil circuit that lubricates the speed reduction unit 20 and circulates in the oil passage 43 that is cooled by the outer peripheral fins 11c in the oil passage 43 provided in the casing 11 cools the motor unit 10 and the speed reduction unit 20 is provided. It is composed.

  Thereby, the axial center oil supply by which lubricating oil is supplied into the inside of the deceleration part 20 from the deceleration part input shaft oil path 45 is implement | achieved, and the motor part 10 and the deceleration part 20 can be lubricated and cooled effectively.

  As shown in FIGS. 3 to 5, the cycloid speed reduction unit 20 rotatably supports two curved plates 24 by eccentric shaft portions 23 provided at two locations of the input shaft 22, and the curved plates 24. The corrugated tooth profile 24a formed on the outer periphery of the speed reducer 20 is engaged with the outer pin 25 disposed inside the casing 11b of the speed reduction portion 20, and the curved plate 24 is caused to eccentrically swing by the rotation of the input shaft 22. The rotation of 24 is output from the output shaft 26 arranged coaxially with the input shaft 22, and the wheel hub 30 is rotated (see FIG. 3).

  The number of outer pins 25 disposed inside the casing 11 b of the speed reduction unit 20 is greater than the corrugated tooth profile 24 a on the outer periphery of the curved plate 24.

  One end of the input shaft 22 is connected to the motor rotating shaft 14 of the rotor 13 by spline fitting and is rotated by the motor unit 10, and an eccentric shaft 23 is provided at the other end. Yes.

  A pair of eccentric shaft portions 23 are provided in the axial direction of the input shaft 22. The pair of eccentric shaft portions 23 is provided such that the center of the cylindrical outer diameter surface is 180 degrees out of phase in the circumferential direction, and a rolling bearing 28 is fitted to each outer diameter surface of the pair of eccentric shaft portions 23. Are combined.

  The input shaft 22 provided with the pair of eccentric shaft portions 23 is provided with a pair of counterweights 55 with a 180 ° phase shift in the circumferential direction so as to sandwich the pair of eccentric shaft portions 23.

  The curved plate 24 is rotatably supported by the input shaft 22 by a rolling bearing 28, and a corrugated tooth profile 24a formed on the outer periphery thereof is a trochoidal curved tooth profile. As shown in FIG. 5, the curved plate 24 has a plurality of pin holes 24b formed at equal intervals on a single circle centered on the rotation axis, and each of the pair of pin holes 24b aligned in the axial direction is formed in each of the pair of pin holes 24b. The pin 29 is inserted with a margin, and a part of the outer periphery of the needle roller bearing 29a rotatably supported by the inner pin 29 is in contact with a part of the inner periphery of the pin hole 24b.

  As described above, the speed reduction portion 20 includes a curved plate 24 as a revolving member that is rotatably held by the eccentric shaft portion 23, and a plurality of outer pins 25 that engage with the corrugated tooth profile 24a on the outer peripheral portion of the curved plate 24. And an output shaft 26 that outputs the rotational movement of the curved plate 24, and a center collar 24c that is attached to a gap between the curved plates 24 and abuts against the end surfaces of the curved plates 24 to prevent the curved plates from tilting.

  The output shaft 26 has a flange portion 26a and a shaft portion 26b. Inner pins 29 are fixed to the flange portion 26 a at equal intervals on a circumference centered on the rotation axis O of the output shaft 26. A wheel bearing portion 31 is fixed to the outer diameter surface of the shaft portion 26b (see FIG. 3).

  As shown in FIG. 5, the outer pins 25 are provided at equal intervals on the circumferential track of the rotation axis O of the input shaft 22. When the curved plate 24 revolves, the outer peripheral corrugated tooth profile 24a and the outer pin 25 engage with each other to cause the curved plate 24 to rotate.

  The outer pin 25 disposed inside the casing 11b is not directly held by the casing 11b. As shown in FIG. 3, the outer pin housing 50 is supported in a floating state with respect to the inner wall of the casing 11b. Is held in. More specifically, as shown in FIG. 4, both ends of the outer pin 25 are rotatably supported by needle roller bearings 51 with respect to the outer pin housing 50. Thus, by making the outer pin 25 rotatable with respect to the outer pin housing 50, the contact resistance due to the engagement with the curved plate 24 can be reduced.

  As shown in FIG. 4, the outer pin housing 50 includes a cylindrical portion 50a and a pair of ring portions 50b extending radially inward from both axial ends of the cylindrical portion 50a.

  The output shaft 26 is rotatably supported via a bearing 52 on the inner periphery of the pair of ring portions 50 b of the outer pin housing 50. The inner diameter surface of the flange portion 26 a of the output shaft 26 and the outer diameter surface of the input shaft 22 are supported through a bearing 53 so as to be relatively rotatable.

  The curved plate 24 is incorporated between the opposing flange portions 26 a of the output shaft 26. Further, both ends of the inner pin 29 penetrating the pin hole 24b of the incorporated curved plate 24 are supported by the flange portion 26a facing the output shaft 26.

  The plurality of inner pins 29 supported by the flange portions 26a opposed to the output shaft 26 are provided at equal intervals on a circumferential track centering on the rotation axis O of the input shaft 22, and have a frictional resistance with the curved plate 24. In order to reduce this, a needle roller bearing 29a is provided at a position where it abuts against the inner wall surface of the pin hole 24b of the curved plate 24. The inner diameter dimension of the pin hole 24b is set to be larger by a predetermined amount than the outer diameter dimension of the inner pin 29 (referred to as “maximum outer diameter including the needle roller bearing 29a”; the same applies hereinafter).

  At both ends in the axial direction of the outer pin housing 50, a plurality of outer pin holding holes 50c penetrating in the thickness direction are provided. The outer pin holding holes 50 c each extend in a direction parallel to the rotation axis O of the input shaft 22 and hold the outer ring 51 a of the needle roller bearing 51. Further, the corresponding outer pin holding holes 50c of the pair of ring portions 50b are provided at the same position in the circumferential direction and face each other. That is, the center axis of the pair of outer pin holding holes 50c coincides, and when the outer pin housing 50 is attached to the casing 11b, the center axis of the outer pin holding hole 50c becomes parallel to the rotation axis O of the input shaft 22. .

  Thereby, the outer pin 25 can be held in parallel with the rotation axis O of the input shaft 22. Since the outer pin holding holes 50c can be simultaneously formed by simultaneous processing, the central axes of the opposed outer pin holding holes 50c can be relatively easily matched.

  Further, from the viewpoint of reducing the weight of the in-wheel motor drive device A, the casings 11a and 11b are formed of a light metal such as an aluminum alloy or a magnesium alloy. On the other hand, it is desirable to form the outer pin housing 50, which requires high strength, from carbon steel.

  As shown in FIG. 4, an outer pin thrust plate 60 is fixed to both side surfaces of the outer pin housing 50 in order to prevent the outer pin 25 from coming off in the axial direction.

  As shown in FIG. 3, the outer pin housing 50 is floatingly supported by a floating pin 71 with respect to the casing 11 b of the speed reducing portion 20 as shown in FIG. 3.

  A plurality of floating pins 71 are arranged at equal intervals in the circumferential direction of the outer pin housing 50.

  As shown in FIG. 7, the floating pin 71 includes an outer pin housing side shaft portion 73 extending toward the outer pin housing 50 with a flange portion 72 interposed therebetween, and a casing side shaft portion 75 extending toward the casing 11 b side of the speed reduction portion 20. Consists of.

  As shown in FIGS. 4 and 6, the outer pin housing 50 is provided with a fixing hole 74 for fixing the outer pin housing side shaft portion 73 of the floating pin 71 in the axial direction.

  Further, as shown in FIG. 3, a fixing hole 82 for fixing the casing side shaft portion 75 of the floating pin 71 is provided in the casing 11 b of the speed reduction portion 20.

  A vibration isolating member 83 such as rubber is fitted between the casing side shaft portion 75 of the floating pin 71 and the fixing hole 82 of the casing 11b that fixes the casing side shaft portion 75, and vibration of the outer pin housing 50 is caused. Transmission to the casing 11b is reduced.

  The outer pin housing side shaft portion 73 of the floating pin 71 and the fixing hole 74 of the outer pin housing 50 are not simply press-fitted, and as shown in FIGS. 6 to 9, the outer peripheral surface of the outer pin housing side shaft portion 73. A plurality of convex portions 76 extending in the axial direction are provided on the outer pin housing, and the plurality of convex portions 76 are press-fitted along the axial direction so as to bite into the inner diameter surface of the fixing hole 74 of the outer pin housing 50, thereby The portion 73 and the fixing hole 74 of the outer pin housing 50 are firmly integrated.

  In order to allow the plurality of convex portions 76 extending in the axial direction to the outer peripheral surface of the outer pin housing side shaft portion 73 of the floating pin 71 to bite into the inner diameter surface of the fixing hole 74 of the outer pin housing 50 along the axial direction, The pin 71 is heat-treated, and the outer pin housing 50 is not heat-treated, or a steel material having a low hardness with respect to the floating pin 71 is used.

  Details of the fastening method between the outer pin housing side shaft portion 73 of the floating pin 71 and the fixing hole 74 of the outer pin housing 50 will be described.

  As shown in FIG. 10, the outer pin housing side shaft portion 73 and the outer pin housing are formed by the plurality of convex portions 76 provided on the outer pin housing side shaft portion 73 biting into the inner diameter surface of the fixing hole 74 of the outer pin housing 50. 50 fixing holes 74 are integrated.

  As shown in FIG. 7, a chamfered portion 77 having an inclination angle θ of 45 ° or less is provided on the top (outer diameter side) of the press-fitting start end surface of the convex portion 76 of the outer pin housing side shaft portion 73.

  As shown in FIGS. 10 and 11, the intermediate portion in the protruding direction of the convex portion 76 corresponds to the position of the inner diameter surface of the fixing hole 74 before forming the concave portion 78 formed by transferring the convex portion 76. That is, the inner diameter surface of the fixing hole 74 is arranged between the small diameter of the convex portion 76 and the large diameter of the convex portion 76. When the large diameter dimension of the convex portion 76 is D1, the small diameter dimension of the convex portion 76 is D2, and the inner diameter surface of the fixing hole 74 is D3, D1> D3> D2. Preferably, {(D1 + D2) / 2}> D3. For this reason, the radial direction fitting range is set to 1/2 or more of the height of the convex portion 76 from the apex of the convex portion 76.

  By the way, the convex part 76 comprises the male spline which consists of a convex part and a recessed part in the outer peripheral surface of the outer pin housing side axial part 73. FIG. This male spline can be formed by various processing methods such as rolling, cutting, pressing, and drawing.

  The outer pin housing side shaft portion 73 and the fixing hole 74 of the outer pin housing 50 are fastened as follows.

  First, the shaft center of the outer pin housing side shaft portion 73 is aligned with the shaft center of the fixing hole 74 of the outer pin housing 50. In this state, the outer pin housing side shaft portion 73 is inserted (press-fitted) into the fixing hole 74 of the outer pin housing 50 as shown in FIG. At this time, as described above, the large-diameter dimension D1 of the convex portion 76, the small-diameter dimension D2 of the convex portion 76, and the inner-diameter surface dimension D3 of the fixing hole 74 of the outer pin housing 50 are as described above. Moreover, since the hardness of the convex portion 76 is larger than the hardness of the inner diameter surface of the fixing hole 74, when the outer pin housing side shaft portion 73 is pressed into the fixing hole 74 of the outer pin housing 50 in the axial direction, the convexity The portion 76 bites into the inner diameter surface of the fixing hole 74, and as shown in FIG. 10, the convex portion 76 forms a concave portion 78 into which the convex portion 76 is fitted along the axial direction. . This press-fitting is performed until the flange portion 72 of the floating pin 71 contacts the end surface of the outer pin housing 50 (see FIG. 9). In addition, when press-fitting, it is possible with general press equipment such as a hydraulic press.

  By the way, when the convex portion 76 of the outer pin housing side shaft portion 73 is pressed into the inner diameter surface of the fixing hole 74 and is pressed into the inner diameter surface of the fixing hole 74, as shown in FIGS. 79 is formed. The protruding portion 79 is the material of the capacity of the inner diameter surface of the fixing hole 74 into which the convex portion 76 is fitted (fitted), and is extruded from the formed concave portion 78, and is cut to form the concave portion 78. Or both extruded and cut.

Further, when the convex portion 76 scrapes the inner diameter surface of the fixing hole 74 to form the concave portion 78, the fixing hole 74 is slightly expanded in diameter, allowing the convex portion 76 to move in the axial direction and moving in the axial direction. If the operation stops, the fixing hole 74 is reduced in diameter to return to the original diameter. In other words, when the convex portion 76 is press-fitted, the outer pin housing side shaft portion 73 is elastically deformed in the radial direction, and a preload corresponding to the elastic deformation is applied to the tooth surface of the convex portion 76 (surface of the concave portion fitting portion). For this reason, the uneven | corrugated fitting structure which the whole recessed part fitting site | part of the convex part 76 closely_contact | adheres to the corresponding recessed part 78 can be formed reliably. That is, a female spline that is in close contact with the male spline is formed on the inner diameter surface of the fixing hole 74 by the spline (male spline) of the outer pin housing side shaft portion 73.
As a result, as shown in FIG. 11, the entire fitting contact portion between the convex portion 76 of the outer pin housing side shaft portion 73 and the concave portion 78 of the fixing hole 74 fitted therein is in close contact. In this case, each convex part 76 and each concave part 78 fitted to this are tight-fitted over the entire circumference in the circumferential direction.

  That is, as shown in FIG. 11, each convex portion 76 has a triangular shape (mountain shape) having a convex rounded apex in cross section, and a fitting contact portion (concave fitting portion) of each convex portion 76. 11 is a range A shown in FIG. 11, which is a range from the middle of the mountain shape to the top of the mountain in the cross section. Further, a gap 80 is formed between the adjacent convex portions 76 in the circumferential direction on the inner diameter side of the inner diameter surface of the fixing hole 74.

  The length of the outer pin housing side shaft portion 73 can be shortened because each convex portion 76 bites into the inner diameter surface of the fixing hole 74, so that a fastening force stronger than simple press-fitting can be obtained.

  The convex portions 76 shown in FIGS. 10 and 11 have a triangular shape with a rounded cross section. However, even if the convex portion 76 has a trapezoidal shape as shown in FIG. 12, the cross section has a triangular shape as shown in FIG. Even if it exists, as shown in FIG. 14, a cross section may be a rectangular shape.

  In the male spline shown in FIG. 11, the pitch of the convex portions and the pitch of the concave portions are set to be the same. For this reason, in the said embodiment, the circumferential direction thickness L0 in the position corresponding to the said intermediate | middle part between the convex parts 76 adjacent to the circumferential direction in the circumferential direction thickness L of the protrusion part 76 convex part 76 is substantially. It is the same.

  On the other hand, as shown in FIG. 12, the circumferential thickness L2 of the projecting direction intermediate portion of the convex portion 76 is set to the circumferential dimension at a position corresponding to the intermediate portion between the convex portions 76 adjacent in the circumferential direction. It may be smaller than L1.

  Further, the embodiment shown in FIG. 15 is an example in which a plurality of recesses 81 having a fastening allowance n are formed in advance on the inner diameter surface of the fixing hole 74 with respect to the plurality of protrusions 76, and each recess 81 having a fastening allowance n. Is formed in advance, the press-fit load when the convex portions 76 of the outer pin housing side shaft portion 73 are transferred to the inner surface of the fixing hole 74 can be reduced. Further, a gap may be provided between the bottom of each recess 81 and the top of each protrusion 76. That is, the fastening allowance n may be provided only on both side surfaces of each convex portion 76.

  As described above, the convex portion 76 extending in the axial direction is provided on the outer peripheral surface of the outer pin housing side shaft portion 73 of the floating pin 71, and the convex portion 76 is axially formed on the inner diameter surface of the fixing hole 74 of the outer pin housing 50. Since the outer pin housing side shaft portion 73 and the fixing hole 74 of the outer pin housing 50 are integrated with each other, the floating pin 71 can be firmly fixed to the outer pin housing 50 rather than simple press-fitting. it can.

  Therefore, the press-fitting length of the floating pin 71 can be shortened, and the size and cost are reduced.

  Further, the polishing process of the floating pin 71 can be omitted as compared with a simple press-fitting type, and the cost is reduced.

  Since the convex portion 76 of the floating pin 71 bites into the outer pin housing 50, there is no deviation in the rotational direction of the floating pin 71, and peeling wear that occurs between the floating pin 71 and the outer pin housing 50 occurs compared to a simple press-fit type. It becomes difficult to do.

  Furthermore, since the convex part 76 of the floating pin 71 bites in while cutting the outer pin housing 50, the deformation of the outer pin housing 50 is small, and the position and accuracy after press-fitting are better than simple press-fitting.

  As shown in FIG. 3, the wheel bearing portion 31 of the wheel hub 30 includes an inner ring member 32 fixedly connected to an outer diameter surface of the shaft portion 26b of the output shaft 26, and the inner ring member 32 can be rotated with respect to the casing 11b. And an outer ring member 33 to be held. A double row rolling element 34 is installed between the inner ring member 32 and the outer ring member 33, and the inner ring member 32, the outer ring member 33 and the double row rolling element 34 constitute a double row angular ball bearing. The inner ring member 32 is integrally provided with a flange portion 35, and a driving wheel (not shown) is fixedly connected to the flange portion 35 by a bolt 36.

The operation principle of the in-wheel motor drive device A having the above configuration will be described in detail.
For example, the motor unit 10 receives an electromagnetic force generated by supplying an alternating current to the coil of the stator 12, and the rotor 13 made of a permanent magnet or a magnetic material rotates.

  Accordingly, when the motor rotation shaft 14 connected to the rotor 13 rotates, the curved plate 24 revolves around the rotation axis O of the motor rotation shaft 14. At this time, the outer pin 25 engages with the curved waveform of the curved plate 24 so as to make rolling contact, and the curved plate 24 rotates in the direction opposite to the rotation of the motor rotating shaft 14.

  The outer diameter of the inner pin 29 inserted through the pin hole 24b of the curved plate 24 is smaller than the inner diameter of the pin hole 24b, and comes into contact with the inner wall surface of the pin hole 24b as the curved plate 24 rotates. Thereby, the revolution movement of the curved plate 24 is not transmitted to the inner pin 29, but only the rotational motion of the curved plate 24 is transmitted to the wheel hub 30 via the output shaft 26.

  At this time, the output shaft 26 arranged coaxially with the rotation axis O takes out the rotation of the curved plate 24 as the output shaft of the speed reduction unit 20, and the rotation of the motor rotation shaft 14 is decelerated by the speed reduction unit 20 to the output shaft 26. Therefore, even when the low torque, high rotation type motor unit 10 is employed, it is possible to transmit the necessary torque to the drive wheels.

Note that the reduction ratio of the speed reduction unit 20 having the above-described configuration is calculated as (Z _A −Z _B ) / Z _B where Z _{A is} the number of outer pins 25 and Z _B is the number of waveforms of the curved plate 24. In the embodiment shown in FIG. 5, 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 20 that can obtain a large reduction ratio without using a multistage configuration, a compact and high reduction ratio in-wheel motor drive device A can be obtained. Further, since the outer pin 25 is rotatable with respect to the outer pin housing 50 and the needle roller bearing 29a is provided at a position where the outer pin 25 contacts the curved plate 24, the frictional resistance is reduced. 20 transmission efficiency is improved.

  In the above-described embodiment, two curved plates 24 of the speed reduction unit 20 are provided with a 180 ° phase change. However, the number of curved plates can be arbitrarily set. For example, three curved plates are provided. When provided, it is preferable to change the phase by 120 °.

  In addition, the description of the operation in the above embodiment has been made by paying attention to the rotation of each member, but in reality, power including torque is transmitted from the motor unit 10 to the drive wheels. Therefore, the power decelerated as described above is converted into high torque.

  In the description of the operation in the above-described embodiment, power is supplied to the motor unit 10 to drive the motor unit 10 and the power from the motor unit 10 is transmitted to the drive wheels. When the vehicle decelerates or goes down a hill, the power from the drive wheel side is converted into high-rotation low-torque rotation by the reduction unit 20 and transmitted to the motor unit 10, good. Furthermore, the electric power generated here may be stored in a battery and used later for driving the motor unit 10 or for operating other electric devices provided in the vehicle.

  Moreover, in the said embodiment, the radial gap motor provided with the stator 12 fixed to the casing 11a at the motor part 10, and the rotor 13 arrange | positioned in the position which faces the inner side of the stator 12 with a radial clearance. Although the example which employ | adopted was shown, the motor of arbitrary structures is applicable not only to this but. For example, an axial gap motor in which the stator and the rotor are arranged to face each other via a gap opened in the axial direction may be used.

  Furthermore, the electric vehicle equipped with the in-wheel motor drive device A according to the present invention may have the rear wheels as drive wheels, the front wheels as drive wheels, or 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.

1: Electric vehicle 2: Chassis 2a: Wheel house 3: Front wheel 4: Drive wheel 5: Suspension device 5a: Suspension arm 5b: Strut 10: Motor part 11: Casing 11a: Casing 11b: Casing 11c: Fin 12: Stator 13: Rotor 14: Motor rotating shaft 15: Bearing 20: Reduction part 22: Input shaft 23: Eccentric shaft part 24: Curved plate 24a: Waveform tooth profile 24b: Pin hole 24c: Center collar 25: Outer pin 26: Output shaft 26a: Flange part 26b: Shaft portion 28: Rolling bearing 29: Inner pin 29a: Bearing 30: Wheel hub 31: Wheel bearing portion 32: Inner ring member 33: Outer ring member 34: Rolling element 35: Flange portion 36: Bolt 43: Oil passage 44: Motor Rotating shaft oil passage 45: Deceleration portion input shaft oil passage 50: Outer pin housing 50a: Cylindrical portion 5 0b: Ring portion 50c: Outer pin holding hole 51: Bearing 51a: Outer ring 52: Bearing 53: Bearing 55: Counterweight 60: Outer pin thrust plate 61: Lubricating oil pump 71: Floating pin 72: Flange portion 73: Outer pin housing Side shaft portion 74: Fixing hole 75: Casing side shaft portion 75: Fixing hole 76: Convex portion 77: Chamfered portion 78: Concavity 79: Protruding portion 81: Concavity 80: Clearance 82: Fixing hole 83: Anti-vibration member A: In-wheel motor drive device

Claims (5)

  A motor unit that generates a driving force, a deceleration unit that decelerates and outputs the rotation of the motor unit, and a wheel hub that transmits the output from the deceleration unit to the drive wheels, and the deceleration unit is an eccentricity provided on the input shaft A curved plate that is rotatably supported by the shaft portion, and an outer pin housing that supports an outer pin that is located on the inner diameter surface of the casing of the speed reduction portion via a gap and meshes with a corrugated tooth formed on the outer periphery of the curved plate; The outer pin housing side fixed shaft portion of the floating pin fixed to the casing is inserted into the fixing holes at both axial ends of the outer pin housing, and the outer pin housing is floatingly supported with respect to the casing. The in-wheel motor drive rotates the wheel hub by rotating the curved plate eccentrically by rotating the input shaft and outputting the rotation of the curved plate from the output shaft arranged coaxially with the input shaft. In the apparatus, a plurality of convex portions extending in the axial direction are provided on the outer peripheral surface of the outer pin housing side fixed shaft portion of the floating pin, and the plurality of convex portions are provided along the inner diameter surface of the fixing hole of the outer pin housing along the axial direction. An in-wheel motor drive device characterized by integrating the outer pin housing side shaft portion and the fixing hole of the outer pin housing.   The in-wheel motor drive device according to claim 1, wherein a plurality of convex portions extending in the axial direction are formed on the outer peripheral surface of the outer pin housing side fixed shaft portion by rolling.   3. The in-wheel motor drive device according to claim 1, wherein the floating pin is heat-treated and the outer pin housing is non-heat-treated, or a steel material having a low hardness with respect to the floating pin is used.   A plurality of recesses having a fastening allowance are formed in advance on the inner diameter surface of the fixing hole with respect to the protrusions, and the plurality of protrusions of the outer pin housing side shaft portion are transferred to the inner diameter surface of the fixing hole. The in-wheel motor drive device in any one of 1-3.   A vehicle equipped with the in-wheel motor drive device according to any one of claims 1 to 4.

Images