JP2015190566A - In-wheel motor driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an in-wheel motor driving device capable of preventing a locked state of a wheel and damage (such as over-load on a motor or a shaft twisting and the like) cause to an electric motor A even if an excessive torque acts due to a locked state of a speed reducer B.SOLUTION: In this invention, a member corresponding to an internal gear of a speed reducer B installed in a housing 22b (a ring gear in the case of a planetary gear type speed reducer and an outer pin housing 50 in the case of a cycloid reduction gear) is stopped against its rotation by a shear-pin 60 to be broken by over-load, thereby, even if an excessive torque is applied to a speed reducer B due to internal trouble of a speed reducer B and the like during driving operation, a shear-pin 60 is broken by a rotating shear force generated between the housing 22b of an in-wheel motor driving device 21 and a member corresponding to an internal gear of the speed reducer B to enable an entire speed reducer B to be rotated in idling so as to prevent a wheel from being locked and an electric motor A from being damaged.

Description

  The present invention provides an in-wheel motor drive having a fail-safe function for preventing wheel locking, motor overload, shaft twisting, and the like when a speed reducer of an in-wheel motor drive device is broken and locked during traveling. Relates to the device.

  The in-wheel motor drive device includes an electric motor that generates a driving force, a reduction gear that receives the output of the electric motor, and a wheel hub that is rotated by the reduction output of the reduction gear (Patent Document 1). Patent Document 2).

  In the in-wheel motor drive device disclosed in Patent Document 1 or Patent Document 2, an electric motor unit and a speed reducer are housed in a housing, and a cycloid speed reducer (Patent Document 1) or a planetary gear speed reducer ( Those having a high reduction ratio such as Patent Document 2) are used.

  Each of these cycloid reducers and planetary gear reducers has an internal gear member that is prevented from rotating inside the housing, and has an external gear member that meshes with the internal gear member and decelerates to output a deceleration output to the wheel hub. I have.

JP 2012-97903 A JP 2013-103672 A

  By the way, in an in-wheel motor drive device using a cycloid reducer or planetary gear reducer with a high reduction ratio, if the reducer locks down due to an internal failure of the reducer, damage may occur to places other than the reducer In addition, there is a possibility that the vehicle may cause a spin due to a single wheel lock.

In general, as a method for avoiding wheel lock, there are the following two methods.
-A method of separating the power transmission by providing the weakest part in advance on the power transmission shaft and breaking it when abnormal.
-A method of providing a torque limiter or clutch on the power transmission shaft and disconnecting the power transmission in the event of an abnormality.

  However, with the above method, traveling after the reduction gear lock is impossible.

Thus, the present invention can prevent damage to the wheel and electric motor (motor overload, shaft twist, etc.) even when the reducer is locked and excessive torque is applied. By performing independent control of each wheel of the wheel motor drive system,
It is an object of the present invention to provide an in-wheel motor drive device capable of running at low torque even after the reduction gear is locked.

  In order to solve the above problems, the present invention includes an electric motor that generates a driving force, a reduction gear that receives the output of the electric motor, and a wheel hub that is rotated by the reduction output of the reduction gear. In the in-wheel motor drive device comprising an external gear member that has an internal gear member that is prevented from rotating inside the housing, and that is engaged with the internal gear member to decelerate and output a deceleration output to the wheel hub, The member that prevents the internal gear member of the speed reducer from rotating with respect to the housing is constituted by a shear pin that is broken by an overload.

  In the speed reducer according to the present invention, an outer pin as an inner tooth member supported on the inner side of the outer pin housing that is prevented from rotating by the shear pin with respect to the housing, and a corrugated tooth profile that meshes with the outer pin are formed on the outer periphery. A cycloid speed reducer that has a curved plate as an external tooth member that is eccentrically oscillated by an eccentric shaft provided on the shaft, outputs the rotation of the curved plate from an output shaft that is arranged coaxially with the input shaft, and rotates the wheel hub Machine, a sun gear as an external gear member provided coaxially on the input shaft, a ring gear as an internal gear member, a plurality of pinion gears provided at equal intervals in the circumferential direction between the sun gear and the ring gear, and a carrier for holding the pinion gear And a planetary gear reducer in which the ring gear is prevented from rotating by the shear pin with respect to the housing. Kill.

  The shaft center of the shear pin that prevents the internal gear member from rotating relative to the housing may be provided in parallel with the rotation axis of the speed reducer, or may be provided to be orthogonal to the rotation axis of the speed reducer.

  In the in-wheel motor drive device according to the present invention, as described above, a member corresponding to the internal gear of the speed reducer mounted in the housing (ring gear for a planetary gear speed reducer, outer pin housing for a cycloid speed reducer) is provided. Because the shear pin is broken by overload, if excessive torque is applied to the reducer due to a malfunction in the reducer during driving, the in-wheel motor drive housing and the reducer The shear pin is broken by the rotational shear force generated between the members corresponding to the gears, and the entire speed reducer can be idled, causing wheel locks and damage to the motor side (motor overload, shaft twist, etc.). Can be prevented.

It is a schematic plan view of the electric vehicle which has an in-wheel motor drive device. It is the figure which looked at the electric vehicle of FIG. 1 from back. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal front view showing an embodiment of an in-wheel motor drive device according to the present invention using a cycloid type reduction gear. FIG. 4 is an enlarged longitudinal front view of the speed reducer of FIG. 3. It is a vertical side view along the III-III line of FIG. It is an enlarged view of an oil pump. It is a perspective view which shows the state which embedded the shear pin in the outer peripheral surface of the outer pin housing. FIG. 8 is a side view of the outer pin housing of FIG. 7. FIG. 8 is a front view of the outer pin housing of FIG. 7. (A) is a front view of a shear pin, (b) is a perspective view of a shear pin. It is a perspective view which shows the state which embedded the shear pin in the outer surface of the outer pin housing. FIG. 12 is a front view of the outer pin housing of FIG. 11. It is a figure which shows an example of the control flow of the in-wheel motor drive device when a shear pin breaks. It is a longitudinal front view which shows embodiment of the in-wheel motor drive device based on the invention which uses the reduction gear of a planetary gear type. It is a partially expanded sectional view of FIG. It is a fragmentary sectional view which shows the example of arrangement | positioning of a shear pin.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  First, the in-wheel motor drive device of embodiment using a cycloid reduction gear as a reduction gear is demonstrated.

  As shown in FIG. 1, the electric vehicle 11 provided with the in-wheel motor drive device has a driving force applied to the chassis 12, front wheels 13 as steering wheels, drive wheels (rear wheels) 14, and left and right drive wheels 14. And an in-wheel motor drive device 21 that transmits As shown in FIG. 2, the drive 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. As a mounting form of the in-wheel motor drive device 21, in addition to the rear-wheel drive system shown in FIGS.

  The suspension device 12b supports the drive wheel 14 by a suspension arm that extends to the left and right, and suppresses vibration of the chassis 12 by absorbing vibration received by the drive 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 or the like is provided at a 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 that drives the left and right drive 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.

  As shown in FIG. 3, the in-wheel motor drive device 21 includes an electric motor A that generates a driving force, a speed reducer B that decelerates and outputs the rotation of the electric motor A, and an output from the speed reducer B as driving wheels. The electric motor A and the speed reducer B are housed in the housing 22 and are mounted in the wheel housing 12a of the electric vehicle 11 as shown in FIG.

  The electric motor A and the speed reducer B are accommodated in the housing 22. The housing 22 includes a housing 22a on the electric motor A side and a housing 22b on the reduction gear B side.

  The electric motor A is of a radial gap type in which a stator 23 is provided on the inner peripheral surface of the housing 22a, and a rotor 24 is provided at an interval on the inner periphery of the stator 23.

  The rotor 24 has a motor shaft 24a in the center, and the motor shaft 24a is connected to the input shaft 30 of the speed reducer B and is inserted into the housing 22b of the speed reducer B. And is supported rotatably.

  The housing 22b of the speed reducer B is provided with an oil tank 41 for lubricating oil at the lower portion, the lubricating oil in the oil tank 41 is sucked by the oil pump 42, and the lubricating oil is supplied to the electric motor A and the speed reducer B for lubrication. And cooling.

  The oil supply passage 43 for supplying lubricating oil to the inside of the speed reducer B extends from the discharge port of the oil pump 42 driven by using the output rotation of the speed reducer B that decelerates the rotation of the electric motor A along the inside of the housing 22a. The rear portion of the housing 22a passes through the internal passage 44 of the motor shaft 24a and the internal passage 45 of the input shaft 30 of the speed reducer B, and the passage extends into the housing 22b of the speed reducer B. The lubricating oil supplied from the oil pump 42 is scattered by the centrifugal force and the pressure of the oil pump 42 from the radial supply port provided in the internal passage 45 of the input shaft 30 of the speed reducer B, and the speed reducer B The inside is lubricated and cooled. A so-called axial center lubrication system is adopted.

  The return passage 46 for the lubricating oil is constituted by a discharge port 47 provided at the bottom of the housing 22 b of the speed reducer B and a passage that reaches the suction port of the oil pump 42 through the oil tank 41.

  As shown in FIG. 6, the oil pump 42 includes an inner rotor 72 that rotates using the output rotation of the speed reducer B, an outer rotor 73 that rotates following the rotation of the inner rotor 72, a pump chamber 74, The cycloid pump includes a suction port 75 that communicates with the return passage 46 and a discharge port 76 that communicates with the oil supply passage 43.

  Inner rotor 72 has a tooth profile formed of a cycloid curve on the outer diameter surface. Specifically, the shape of the tooth tip portion 72a is an epicycloid curve, and the shape of the tooth gap portion 72b is a hypocycloid curve. The inner rotor 72 rotates integrally with the output shaft 33 of the speed reducer B.

  The outer rotor 73 has a tooth profile formed of a cycloid curve on the inner diameter surface. Specifically, the shape of the tooth tip portion 73a is a hypocycloid curve, and the shape of the tooth gap portion 73b is an epicycloid curve. The outer rotor 73 is rotatably supported by the pump case 77.

  The inner rotor 72 rotates around the rotation center c1. On the other hand, the outer rotor 73 rotates around a rotation center c2 different from the rotation center c1 of the inner rotor 72. Further, when the number of teeth of the inner rotor 72 is n, the number of teeth of the outer rotor 73 is (n + 1). In this embodiment, n = 5.

  A plurality of pump chambers 74 are provided in the space between the inner rotor 72 and the outer rotor 73. When the inner rotor 72 rotates using the rotation of the output shaft 33 of the speed reducer B, the outer rotor 73 rotates in a driven manner. At this time, since the inner rotor 72 and the outer rotor 73 rotate around different rotation centers c1 and c2, the volume of the pump chamber 74 continuously changes. As a result, the lubricating oil flowing in from the suction port 75 is pumped from the discharge port 76 to the oil supply passage 43.

  As shown in FIG. 3, the housing 22b of the speed reducer B is provided with an oil tank 41 for lubricating oil at the lower portion. The lubricating oil in the oil tank 41 is sucked by the oil pump 42 through the return passage 46, and the electric motor A Lubricating oil is supplied to the reduction gear B to perform lubrication and cooling.

  As shown in FIGS. 3 to 5, the cycloid reduction gear B supports two curved plates 31 rotatably by eccentric shaft portions 30 a and 30 b provided on the input shaft 30, and these curved plates 31. The corrugated tooth profile 31a formed on the outer periphery of the gear is engaged with the outer pin 32 disposed inside the housing 22b of the speed reducer B, and the curved plate 31 is caused to eccentrically swing by the rotation of the input shaft 30. The rotation of 31 is output from the output shaft 33 arranged coaxially with the input shaft 30, and the wheel hub C is rotated.

  The number of outer pins 32 disposed inside the housing 22b of the reduction gear B is greater than the corrugated tooth profile 31a on the outer periphery of the curved plate 31.

  As shown in FIG. 3, the outer pin 32 is supported by an outer pin housing 50 that is disposed on the inner diameter surface of the housing 22 b of the speed reducer B via a gap. The outer pin housing 50 is prevented from rotating by the shear pin 60 with respect to the housing 22b of the speed reducer B. As shown in FIGS. 7 to 9, the outer pin housing 50 has a cylindrical shape having a pair of flange portions 51 on the inner diameter side of both axial end surfaces.

  The pair of flange portions 51 of the outer pin housing 50 are provided with a plurality of outer pin holding holes 54 penetrating in the thickness direction. As shown in FIG. 4, the outer pin holding hole 54 extends in a direction parallel to the rotation axis of the input shaft 30 and holds both ends of the outer pin 32. Both ends of the outer pin 32 are supported by the outer pin holding hole 54 via bearings 55.

  The corresponding outer pin holding holes 54 of the pair of flange portions 51 are provided at the same position in the circumferential direction so as to face each other. That is, the center axes of the pair of outer pin holding holes 54 coincide with each other, and when the outer pin housing 50 is attached to the housing 22 b of the reduction gear B, the center axis of the outer pin holding holes 54 is parallel to the rotation axis of the input shaft 30. become. Thereby, the outer pin 32 can be held in parallel with the rotation axis of the input shaft 30.

  As shown in FIG. 7, a groove-shaped counterbore portion 57 is formed in the thick portion located on the radially inner peripheral side of the pair of flange portions 51 so as to continue to the outer pin holding hole 54. .

  In the embodiment shown in FIGS. 3 and 4, the bearing 55 includes a needle formed of an outer ring 55 a and needle rollers 55 b in which the inner peripheral surface of the outer ring 55 a and the outer peripheral surface of the outer pin 32 are rolling surfaces. A tapered roller bearing is used.

  As shown in FIG. 10, the shear pin 60 is provided with a V-shaped notch 60a or the like which is the weakest part at the intermediate portion of the shaft body, and adjusts the diameter and material of the shaft body itself and the diameter of the notch 60a. By doing so, the breaking load can be adjusted. The shape of the notch 60a is not limited to the V shape, and any shape that can control the breaking load such as a U shape or a concave shape can be adopted. As a material of the shear pin 60, for example, S45C can be used.

  In the embodiment of FIG. 3, the shear pin 60 is decelerated on the outer peripheral surface of the outer pin housing 50 and the inner peripheral surface of the housing 22 b of the reducer B as shown in FIGS. 7 to 9. It is embedded and supported so as to be orthogonal to the rotational axis of the machine B. A plurality of shear pins 60 are preferably embedded and supported on the outer peripheral surface of the outer pin housing 50. In this embodiment, four shear pins 60 are equally arranged in the circumferential direction at intervals of 90 degrees.

  In the embodiment shown in FIGS. 11 and 12, the shear pin 60 is arranged on the outer surface of the outer pin housing 50 and the inner surface of the housing 22 b of the speed reducer B, and the shaft center of the shear pin 60 is the rotational axis of the speed reducer B. It is an example which is embedded and supported so as to be parallel. It is better that a plurality of shear pins 60 are embedded and supported on the outer surface of the outer pin housing 50. In this embodiment, four shear pins 60 are evenly arranged in the circumferential direction at intervals of 90 degrees and are located on both outer surfaces. It is supported by eight shear pins 60.

  The shear pin 60 has a function of stopping the outer pin housing 50 of the speed reducer B from rotating in the circumferential direction with respect to the housing 22b of the speed reducer B. The speed reducer B locks and excessive torque is applied to the outer pin housing 50. Is broken at the notch 60a portion, the anti-rotation function of the outer pin housing 50 is eliminated, and the entire reduction gear B plays a role of idling.

  Accordingly, when excessive torque is applied to the speed reducer B due to an internal failure of the speed reducer B during traveling, a member corresponding to the housing 22b of the in-wheel motor drive device 21 and the internal gear of the speed reducer B, that is, The shear pin 60 is broken by the rotational shear force generated between the outer pins 32 supported by the outer pin housing 50 and the entire reduction gear B is idled, thereby locking the wheel, overloading the electric motor A, and twisting the shaft. Etc. can be prevented.

  By using the shear pin 60, for example, the fail-safe function can be enhanced by a control flow as shown in FIG.

  The control flow shown in FIG. 13 is a control flow when a cycloid type speed reducer is used as the speed reducer B.

  That is, when the normal control is performed (F1), if it is detected that the entire reduction gear B is rotating due to breakage of the shear pin 60 (YES in F2), the electric motor A is turned off (F3). When it is detected that the vehicle speed becomes 0 after turning off the electric motor A (YES in F4), emergency control (F5) is performed.

  In emergency control, for example, the rotation direction of a cycloid reducer changes depending on input and output, but if it does not function as a reducer due to a failure, the rotation direction does not change due to input / output. And control to reverse the inversion. Further, the output torque of the normal side in-wheel motor drive device may be saved in accordance with the output torque of the fault side in-wheel motor drive device (without amplification by the speed reducer B). By doing in this way, it is the feature of this invention that the driving | running | working after a reduction gear lock is attained, and is a difference with the conventional method which avoids a wheel lock | rock.

  As shown in FIG. 4, a pair of eccentric shaft portions 30 a and 30 b are provided in the axial direction of the input shaft 30. The pair of eccentric shaft portions 30a and 30b is provided such that the center of the cylindrical outer diameter surface is 180 degrees out of phase in the circumferential direction, and rolls to the outer diameter surface of each of the pair of eccentric shaft portions 30a and 30b. A bearing 34 is fitted.

  The input shaft 30 provided with the pair of eccentric shaft portions 30a and 30b is provided with a pair of counterweights 35 with a 180 ° phase shift in the circumferential direction so as to sandwich the pair of eccentric shaft portions 30a and 30b.

  The curved plate 31 is rotatably supported on the input shaft 30 by the rolling bearing 34, and the corrugated tooth profile 31a formed on the outer periphery thereof is a trochoidal curved tooth profile. As shown in FIG. 5, the curved plate 31 has a plurality of pin holes 36 formed at equal intervals on a circle centered on the rotation axis, and each of the pair of pin holes 36 aligned in the axial direction is internally formed. The pin 37 is inserted with a margin, and a part of the outer periphery of the roller bearing 37 a rotatably supported by the inner pin 37 is in contact with a part of the inner periphery of the pin hole 36.

  As shown in FIG. 4, the speed reducer B is engaged with two curved plates 31 as revolving members that are rotatably held by the eccentric shaft portions 30 a and 30 b and a corrugated tooth profile 31 a on the outer peripheral portion of the curved plate 31. A plurality of outer pins 32, an output shaft 33 that outputs the rotational movement of the curved plate 31, and a gap between the two curved plates 31 are in contact with the end surfaces of the curved plates 31 to prevent the curved plate from tilting. And a center collar 38.

  The output shaft 33 has a flange portion 33a and a shaft portion 33b. As shown in FIG. 3, inner pins 37 are fixed to the flange portion 33 a at equal intervals on a circumference centered on the rotation axis of the output shaft 33. As shown in FIG. 3, a wheel hub C is provided on the outer diameter surface of the shaft portion 33b so that torque can be transmitted by serration (or spline). A pump drive shaft 33 c connected to the inner rotor 72 of the oil pump 42 is provided at the end of the output shaft 33 on which the flange portions 33 a and 33 a are connected via a plurality of inner pins 37 on the electric motor A side.

  The outer pins 32 are provided at equal intervals on the circumferential track of the rotation axis of the input shaft 30. In FIG. 5, when the input shaft 30 rotates counterclockwise on the paper surface, the curved plate 31 performs a revolving motion, and the curved waveform 31 a and the outer pin 32 engage with each other, whereby the curved plate 31 is Clockwise rotation occurs. As described above, the cycloid reduction gear is a reduction gear whose direction of rotation is reversed between input rotation and output rotation.

  As shown in FIG. 4, the output shaft 33 and the stabilizer 33 d are rotatably supported via a bearing 90 on the inner periphery of the flange portion 51 of the outer pin housing 50. Further, the inner diameter surface of the flange portion 33 a and the stabilizer 33 d of the output shaft 33 and the outer diameter surface of the input shaft 30 are supported through a bearing 91 so as to be relatively rotatable.

  The curved plate 31 is incorporated between the flange portion 33a and the stabilizer 33d facing the output shaft 33. Further, both ends of the inner pin 37 penetrating the pin hole 36 of the incorporated curved plate 31 are supported by the flange portion 33 a facing the output shaft 33.

  The plurality of inner pins 37 supported by the flange portion 33 a and the stabilizer 33 d that face the output shaft 33 are provided at equal intervals on a circumferential track centering on the rotational axis of the input shaft 30, and friction with the curved plate 31. In order to reduce the resistance, needle roller bearings 37a are provided at positions where they contact the inner wall surfaces of the pin holes 36 of the two curved plates 31. The inner diameter dimension of the pin hole 36 is set to be larger than the outer diameter dimension of the inner pin 37 (referred to as “maximum outer diameter including the needle roller bearing 37a”; the same applies hereinafter).

  From the viewpoint of reducing the weight of the in-wheel motor drive device 21, the housing 22 is 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 steel.

  As shown in FIG. 1, the wheel hub C includes an inner ring member 81 fixedly connected to the outer diameter surface of the shaft portion 33b of the output shaft 33, and an outer ring member 82 that rotatably holds the inner ring member 81 with respect to the housing 22b. With. The inner ring member 81 and the outer ring member 82 constitute a double-row angular ball bearing, and a double-row rolling element 83 is installed between the inner ring member 81 and the outer ring member 82. The inner ring member 81 is integrally provided with a wheel mounting flange portion 84.

  In the above-described embodiment, an example of a cylindrical roller bearing has been shown as the rolling bearing 34 that supports the curved plate 31. However, the present invention is not limited to this example. For example, a plain bearing, a deep groove ball bearing, a tapered roller bearing, and a needle roller 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.

  Further, in the above-described embodiment, the radial gap includes the electric motor A including the stator 23 fixed to the housing 22a and the rotor 24 disposed at a position facing the inner side of the stator 23 with a radial gap. Although the example which employ | adopted the motor was shown, the motor of arbitrary structures is applicable, without restricting to this. 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 21 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.

  Next, an embodiment of an in-wheel motor drive device that uses a planetary gear speed reducer as the speed reducer B will be described.

  As shown in FIG. 14, the in-wheel motor drive device 21 using the planetary gear speed reducer is also coaxial with the electric motor A, the speed reducer B driven by the output of the electric motor A, and the input shaft 113 of the speed reducer B. The wheel hub C rotated by the output member 114 and the housing 116 that houses the electric motor A and the speed reducer B are the main components.

  The housing 116 has a cylindrical portion 117 and a front end 118 in the radial direction provided at the front end (end on the outboard side, end on the left side in the figure). The center portion of the front end portion 118 is opened, the rear end portion of the outer member 121 of the wheel hub C is fitted into the opening hole 119, and the flange 122 is fixed to the front end portion 118 with a bolt 123.

  Between the flange 122 of the wheel hub C and the front end portion 118 of the housing 116, in order to prevent leakage of the lubricating oil in the speed reducer B at the outer diameter position of the bolt fixing hole formed in the front end portion 118 of the housing 116. And an O-ring 169.

  A partition wall base 118 a having a larger diameter than the opening hole 119 is provided inside the front end portion 118 of the housing 116. A dish-shaped partition member 120 is fixed to the partition base 118a by a bolt 120a. A center hole 125 is provided at the center of the partition member 120. The center hole 125 faces the outer diameter surface of the input shaft 113 with a radial gap. A partition wall 124 is formed by the partition base 118a and the partition member 120 connected and fixed thereto. The partition wall 124 has a function of dividing the inside of the housing 116 into a storage space for the electric motor A on the outer diameter side and a storage space for the reduction gear B on the inner diameter side.

  Suspension coupling portions 127 protruding in the axial direction are provided at two positions symmetrical with respect to the rear end edge of the cylindrical portion 117 of the housing 116. In the conventional automobile, the wheel hub C is connected to the suspension via the knuckle of the vehicle body. However, in the case of the embodiment of FIG. 14, the suspension connecting portion 127 that is a part of the housing 116 is connected to the vehicle body side. Can be directly connected.

  Since the housing 116 functions as a knuckle, it can be said that the housing 116 has a structure in which the knuckle is integrated. In this case, when the outer member 121 of the wheel hub C needs to be replaced, it is not necessary to remove the housing 116 from the suspension, and the replacement can be performed only by removing the bolt 123.

  In the illustrated case, the electric motor A is a radial gap type brushless DC motor, and is arranged with a stator 128 fixed to the inner surface of the cylindrical portion 117 of the housing 116 and a radial gap on the inner surface of the stator 128. And a rotor 129. The rotor 129 is fitted and fixed to the input shaft 113 by the rotor support member 131.

  The rotor support member 131 includes a support member cylindrical portion 131a (see FIG. 15) fitted to the inner diameter portion of the rotor 129, and a support member disk portion 131b that extends rearward along the partition wall 124 and is bent in the inner diameter direction. Composed. A boss portion 131 c is provided on the inner diameter portion of the support member disk portion 131 b, the boss portion 131 c is fitted to the input shaft 113, and is fixed to the input shaft 113 by the keying portion 135.

  The boss 131c is inserted on the inner diameter side of the center hole 125 of the partition wall 124, and an oil seal member 136 is interposed between the center hole 125 and the boss 131c (see FIG. 15). The partition 124 and the oil seal member 136 partition the storage portion of the electric motor A and the storage portion of the reduction gear B and are oil-sealed. As a result, the lubricating oil on the reduction gear B side is prevented from moving to the electric motor A side, the electric motor A side is kept dry, and the problem that the lubricating oil hinders the rotation of the rotor 129 is removed.

  The reduction gear B is of a planetary gear type. As shown in FIG. 15, the input shaft 113, the output member 114, a sun gear 139 attached to the outer diameter surface of the input shaft by a key stopper 138, and the sun gear A ring gear 142 disposed along the inner diameter surface of the boundary portion between the partition wall base 118a and the partition wall member 120 on the outer periphery of the partition wall 139, and three circumferentially spaced intervals between the ring gear 142 and the sun gear 139. The pinion gear 143 is configured. The pinion gear 143 is supported by a pinion pin 145 via a needle roller bearing 144.

  The ring gear 142 is prevented from rotating with respect to the housing 116 by the shear pin 60.

  That is, as shown in FIG. 16, a predetermined interval is formed between the outer periphery of the ring gear 142 and the inner diameter portion of the partition wall base portion 118a of the housing 116, and the shear pins 60 are embedded at a plurality of locations in the circumferential direction. I am letting.

  Therefore, when an excessive torque is applied to the ring gear 142, the shear pin 60 is broken and the entire speed reducer B is rotated to prevent the wheel from being locked, the electric motor A from being overloaded, the shaft being twisted, and the like. .

  As shown in FIG. 14, the electric motor A and the speed reducer B are within the range of the axial length of the cylindrical portion 117 of the housing 116 except for the rear end portion (inboard side end portion) of the input shaft 113. The rear cover 173 is fitted to the rear end portion of the cylindrical portion 117 via the seal member 160. A heat dissipating fin 174 is provided on the outer surface of the rear cover 173 so as to dissipate the heat of the electric motor A to the outside.

  A rotation sensor 175 is provided between the center hole of the rear cover 173 and the input shaft 113 passing through the center hole, and the portion is closed by the sensor cover 177. The illustrated rotation sensor 175 is a resolver, and its sensor stator 175 a is fixed to the center hole of the rear cover 173, and the sensor rotor 175 b is attached to the input shaft 113.

  A lead wire 179 of the sensor stator 175a is connected to a connector insertion portion 178 provided outside the sensor cover 177. As the rotation sensor 175, a Hall element or the like can be used in addition to the resolver. A connector (not shown) of the signal line cable is inserted into the connector insertion portion 178.

  The rotation angle of the input shaft 113 detected by the rotation sensor 175 is input to a control circuit (not shown) via the signal line cable and used for rotation control of the electric motor A.

  The wheel hub C of the embodiment shown in FIG. 14 includes an inner member 146 in which the hub 186 is integrated, a pair of inner rings 187 fitted to the outer diameter surface of the inner member 146, and an outer member having a flange 122. The outer ring 188 is fitted to the inner surface of the outer member 121 and has a double-row track, and the double-row balls 189 that are desired to be interposed between the inner ring 187 and the outer ring 188. The wheels are attached to the hub 186 by hub bolts 190.

  The connecting shaft portion 147 of the output member 114 is splined to the inner diameter surface of the inner member 416, and the distal end portion of the connecting shaft portion 147 protruding outward from the inner member 146 is fixed by the nut 150 as described above. The Instead of the fixing means using the nut 150, fixing means such as press-cut joining, diameter expansion caulking, or rocking caulking can be employed.

  The wheel hub C of the embodiment shown in FIG. 14 has a so-called first generation type, but a second generation or third generation type can be used.

11: Electric vehicle 12: Chassis 12a: Wheel housing 12b: Suspension device 13: Front wheel 14: Drive wheel 21: In-wheel motor drive devices 22, 22a, 22b: Housing 23: Stator 24: Rotor 24a: Motor shafts 25a, 25b: Bearing 30: Input shaft 30a, 30b: Eccentric shaft portion 31: Curved plate 31a: Wave tooth shape 32: Outer pin 33: Output shaft 33a: Flange portion 33b: Shaft portion 33c: Pump drive shaft 33d: Stabilizer 34: Rolling bearing 35: Counterweight 36: Pin hole 37: Inner pin 37a: Bearing 38: Center collar 41: Oil tank 42: Oil pump 43: Oil supply passage 44, 45: Internal passage 46: Return passage 47: Discharge port 50: Outer pin housing 51: Flange portion 54: outer pin holding hole 55: bearing 55a Outer ring 57: Counterbore 60: Shear pin 60a: Notch 72: Inner rotor 72a: Tooth portion 72b: Tooth portion 73: Outer rotor 73a: Tooth portion 73b: Tooth portion 74: Pump chamber 75: Inlet 76: Exhalation Outlet 77: Pump case 81: Inner ring member 82: Outer ring member 83: Rolling element 84: Wheel mounting flange portions 90, 91: Bearing A: Electric motor B: Reducer C: Wheel hub

Claims (6)

  An electric motor that generates a driving force, a reduction gear that receives the output of the electric motor, and a wheel hub that is rotated by the reduction output of the reduction gear. An in-wheel motor drive device having a tooth member, and having an outer tooth member that meshes with the inner tooth member and decelerates and outputs a deceleration output to the wheel hub, wherein the inner tooth member of the speed reducer is prevented from rotating with respect to the housing. The in-wheel motor drive device characterized by comprising the member to do with the shear pin fracture | ruptured by overload.   An outer pin as an inner tooth member supported on the inner side of the outer pin housing that is prevented from rotating with respect to the housing by the shear pin, and a corrugated tooth profile that meshes with the outer pin is formed on the outer periphery and provided on the input shaft. A cycloid reducer that includes a curved plate as an external tooth member that is eccentrically oscillated by an eccentric shaft portion, outputs the rotation of the curved plate from an output shaft arranged coaxially with the input shaft, and rotates a wheel hub The in-wheel motor drive device according to claim 1.   The reduction gear holds a sun gear as an external tooth member provided coaxially on the input shaft, a ring gear as an internal tooth member, a plurality of pinion gears provided at equal intervals in the circumferential direction between the sun gear and the ring gear, and the pinion gear 2. An in-wheel motor drive device according to claim 1, wherein the ring gear is a planetary gear speed reducer comprising a carrier that performs rotation, and the ring gear is prevented from rotating with respect to the housing by the shear pin.   The in-wheel motor drive device according to claim 1, wherein an axial center of a shear pin that prevents the internal gear member from rotating relative to the housing is orthogonal to a rotational axis of the speed reducer.   The in-wheel motor drive device according to claim 1, wherein an axis of a shear pin that prevents the internal gear member from rotating relative to the housing is parallel to a rotation axis of the speed reducer.   The in-wheel motor drive according to any one of claims 1 to 5, wherein after the one-wheel lock is detected, control suitable for emergency low-speed driving is performed on the torque, rotation speed, and rotation direction of the left and right wheels. Control system using equipment.