JP2018158620A - Park lock mechanism, and in-wheel motor drive device including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a park lock mechanism which can surely release engagement between a park gear and an engaging member even when the engaging member of the park lock mechanism receives reaction force from a wheel side park gear in a case that the park lock mechanism is installed at a driving device driving a wheel by a motor.SOLUTION: A park lock mechanism (41) comprises: a park gear (42); and an engaging member (43) which is selectively positioned at a lock position where rotation of the park gear is prohibited by engaging with the park gear or a lock release position where rotation of the park gear is allowed by retreating from the lock position. The engaging member includes: a first rolling member (43k) in rolling contact with a gear tooth (42g) of the park gear; and a first support part (43g) rotatably supporting the first rolling member. The park gear includes a recess part (42a) in which the recess part receives the first rolling member to engage with the engaging member.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a park lock mechanism that is provided in a vehicle motor drive device that drives wheels with a motor, and that keeps the wheels from rotating by a driver's operation.

  Japanese Patent Laying-Open No. 2008-151308 (Patent Document 1) describes a technique in which a parking lock mechanism is provided in an in-wheel motor drive device. This parking lock mechanism includes a park gear fixed to a drive shaft of an in-wheel motor drive device, and an engagement piece that is supported by a support shaft in a swingable manner and has an engagement protrusion that engages with the park gear at one end thereof. When the rotation of the shaft is prohibited, the engagement piece is moved to engage the engagement protrusion with the locking tooth of the park gear. When the rotation of the drive shaft is allowed, the engagement piece is moved to move the engagement protrusion. Is away from the park gear.

JP 2008-151308 A

  However, the present inventor has found that there is a further improvement in the conventional in-wheel motor drive device. In other words, when the park lock mechanism is operated with the vehicle of Patent Document 1 parked on a slope with a large gradient, a large reaction force is applied from the park gear to the engagement protrusion due to the reaction force from the wheels due to the slope angle of the slope and the vehicle weight. As a result, the frictional force at the contact portion between the park gear and the engagement protrusion is increased, and the engagement between the park gear and the engagement piece is difficult to be released.

  In particular, when the parking lock mechanism is provided in each of the pair of left and right in-wheel motor driving devices as in Patent Document 1, the parking lock mechanism of one wheel may be difficult to be released. Specifically, even when the unlocking operation of the park lock mechanism is started at the same time on the left and right, the frictional force due to the reaction force from the wheel at the contact portion between the park gear and the engagement protrusion differs between the left and right, and the actual release timing is shifted. there is a possibility. There is also a possibility that only one wheel is released. If the timing of unlocking the left and right wheels shifts, not only does the driver feel uncomfortable, but if only one wheel is released, normal driving cannot be performed.

  Further, in Patent Document 1, a separation spring is attached to the engagement piece, and the engagement piece urges a force in a direction to release the engagement between the engagement protrusion and the engagement tooth by the separation spring. In particular, since the above-described frictional force is increased on a slope with a large gradient, the force that exerts a necessary engagement on the separation spring is also increased. Then, this time, when starting the park lock mechanism, it is necessary to apply a force larger than the urging force in the releasing direction of the separation spring to the engagement piece, and a high output actuator for operating the contact engagement piece is required. Become. An actuator that outputs a large actuation force has a problem that it is heavy and expensive.

  In view of the above situation, the present invention provides a park gear on the wheel side when the parking lock mechanism is provided in a drive device that drives a wheel with a motor, such as by parking on a slope with a large gradient. An object of the present invention is to provide a structure that reliably releases the engagement between the park gear and the engagement member even when the reaction force is received from the vehicle. The purpose is also to downsize the park lock mechanism.

  For this purpose, the park lock mechanism according to the present invention is provided in a vehicle motor drive device that drives a wheel by a motor, and a park gear that rotates together with the wheel, and a lock position and a lock that engage with the park gear and prohibit the rotation of the park gear. And an engagement member that is selectively moved to any one of the unlock positions that retreat from the position and allow rotation of the park gear. The engaging member includes a first rolling member that is in rolling contact with the park gear, and a first support portion that rotatably supports the first rolling member. The park gear has a recess, and engages with the engagement member by receiving the first rolling member of the engagement member in the recess. A rolling element such as a sliding bearing or a needle may be interposed between the first rolling member and the first support portion.

  According to the present invention, since the first support portion rotatably supports the first rolling member, even when the first rolling member receives a reaction force from the park gear at the locking position of the engaging member, When the combined member is moved to the unlocking position, the rolling member can be brought into rolling contact with the park gear. Thus, since the rolling member retreats from the recess of the park gear by rolling, the engaging member does not slide in contact with the park gear. The engaging member can move from the locked position toward the unlocked position with a small force. According to the present invention, the engagement member is provided with the separation member such as a spring, and the unlocking can be smoothly realized only by the urging force of the separation member. The vehicle motor drive device may be mounted on a vehicle body and connected to a wheel by a drive shaft, or may be an in-wheel motor drive device disposed inside the wheel.

  The shape of the park gear is not particularly limited as long as it is a gear (gear) shape. As one embodiment of the present invention, the concave portion is oriented in the outer diameter direction of the park gear, and both side surfaces of the concave portion are inclined so that the interval increases from the inner diameter side toward the outer diameter side. According to this embodiment, since the rolling member rolls on the inclined side surface of the recess, the rotation becomes easy, and the engaging member can move from the locked position to the unlocked position with an even smaller force. As another embodiment, both side surfaces of the recess may be substantially parallel.

  The shape of the first support part and the shape of the first rolling member are not particularly limited. As a preferred embodiment of the invention, the first support portions are provided on both sides of the engaging member so as to face each other, and the first rolling member has a cylindrical shape in which both ends are rotatably supported by the pair of first support portions. Laura. According to this embodiment, the center part of the 1st rolling member surely enters into the recessed part of a park gear, and a locked state can be implement | achieved reliably. The first rolling member rolls smoothly while contacting the side surface of the recess.

  As a further preferred embodiment of the present invention, a center portion having a rotation center and a cam portion projecting from the center portion to the outer diameter side, and the engaging member is locked by the cam portion by rotation around the rotation center. A park cam that presses toward is further provided. The cam portion includes a second rolling member that is in rolling contact with the engaging member, and a second support portion that rotatably supports the second rolling member. According to this embodiment, since the cam portion is in rolling contact with the engaging member, the park cam can move the engaging member with a force that is much smaller than in the prior art. Therefore, the actuator for driving the park cam can be further reduced in size. In particular, when the actuator is electrified, there is an actual advantage that it contributes to reduction in output, power saving, size reduction, and weight reduction. As another embodiment, the cam portion of the park cam may be in sliding contact with the engaging member.

  As one embodiment of the present invention, the second support portion of the park cam is provided on both sides of the park cam so as to face each other, and the second rolling member of the park cam is cylindrically supported at both ends rotatably by the pair of second support portions. The roller. According to this embodiment, since the center part of a 2nd rolling member rolls contacting an engaging member, the smooth rolling contact of a 2nd rolling member is realizable.

  The park lock mechanism of the present invention may be provided in an in-wheel motor drive device arranged in an inner space area of a wheel. That is, the in-wheel motor drive device of the present invention has a hub wheel including a coupling portion for coupling with a wheel, a fixed wheel, and a plurality of rolling elements interposed in an annular gap between the hub wheel and the fixed wheel. A wheel hub bearing that rotatably supports the hub wheel, a motor unit that drives the hub wheel, the park lock mechanism that is provided in the drive transmission path from the motor unit to the hub wheel, a park gear, an engagement member, And a casing for accommodating the drive transmission path. According to the present invention, in the pair of left and right in-wheel motor driving devices that respectively drive the left and right wheels of the vehicle, unlocking of the left and right wheel park lock mechanisms can be realized simultaneously. Therefore, there is no possibility that the unlocking timing is shifted between the left and right wheels as in the prior art, and normal running of the vehicle is realized. As another embodiment, the park lock mechanism of the present invention may be provided in a vehicle motor drive device mounted on a vehicle body. This vehicle motor drive device forms a pair of left and right, and is connected to the left and right wheels via a drive shaft. Alternatively, as another embodiment, the park lock mechanism of the present invention may be provided in a vehicle motor drive device that simultaneously drives the left and right wheels with a differential gear device.

  As described above, according to the present invention, in the vehicle motor drive device provided with the park lock mechanism, the locked state can be released with a small force, and the park lock mechanism can be reduced in size and weight, and consequently the vehicle motor. Contributes to reducing the size and weight of the drive unit.

It is a schematic diagram which shows a park lock mechanism. It is an expanded sectional view showing an in-wheel motor drive which comprises a park lock mechanism. It is the enlarged view which shows the same embodiment made into the locked state by the park lock mechanism which becomes 1st Embodiment of this invention. FIG. 4 is a longitudinal sectional view taken along line IV-IV in FIG. 3. It is a cross-sectional view in the VV line of FIG. It is a cross-sectional view showing the embodiment in the unlocked state. It is a cross-sectional view which shows a mode that the rolling member of a park pole receives reaction force from a park gear. It is a schematic diagram which shows a mode that the rolling member of a park pole rolls and contacts a park gear. It is an enlarged view which shows the park lock mechanism which becomes 2nd Embodiment of this invention. It is a longitudinal cross-sectional view in the XX line of FIG. FIG. 11 is a transverse sectional view taken along line XI-XI in FIG. 10. It is a cross-sectional view showing the second embodiment in the unlocked state. It is a schematic diagram which shows a mode that the conventional park pole is in sliding contact with the park gear.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 and FIG. 2 are schematic views showing a park lock mechanism, and also show an in-wheel motor drive device equipped with the park lock mechanism. FIG. 1 is a cross-sectional view showing the in-wheel motor drive device, and shows the inside of the in-wheel motor drive device as viewed from the outside in the vehicle width direction of the electric vehicle. In FIG. 1, the left side of the drawing represents the front of the vehicle, the right side of the drawing represents the rear of the vehicle, the upper side of the drawing represents the upper side of the vehicle, and the lower side of the drawing represents the lower side of the vehicle. FIG. 2 is a developed sectional view schematically showing the in-wheel motor drive device. The cross section shown in FIG. 2 is a developed plane in which the plane including the axis M and the axis N shown in FIG. 1 and the plane including the axis N and the axis O are connected in this order. In FIG. 2, the left side in the drawing represents the outside in the vehicle width direction, and the right side in the drawing represents the inside in the vehicle width direction.

  As shown in FIG. 2, the in-wheel motor drive device 10 includes a wheel hub bearing portion 11 provided at the center of a wheel (not shown), a motor portion 21 that drives the wheel, and a wheel hub bearing that decelerates the rotation of the motor portion. The speed reduction part 31 which transmits to the part 11 and the park lock mechanism 41 which hold | maintains a wheel non-rotatably are provided. The motor unit 21 and the speed reduction unit 31 are arranged offset from the axis O of the wheel hub bearing unit 11. The axis O extends in the vehicle width direction and coincides with the axle. Regarding the position in the axis O direction, the wheel hub bearing portion 11 is disposed on one side (outboard side) in the axial direction of the in-wheel motor driving device 10, and the motor portion 21 is on the other side (inboard side) in the axial direction of the in-wheel motor driving device 10. The speed reduction part 31 is arrange | positioned in the axial direction center part of the in-wheel motor drive device 10. FIG.

  The in-wheel motor drive device 10 is a vehicle motor drive device that drives wheels of an electric vehicle. The in-wheel motor drive device 10 is connected to a vehicle body (not shown). The in-wheel motor drive device 10 can drive an electric vehicle at a speed of 0 to 180 km / h.

  As shown in FIG. 2, the wheel hub bearing 11 is a rotating inner ring / fixed outer ring, and is arranged coaxially on the outer diameter side of the inner ring 12 and the inner ring 12 as a rotating wheel (hub wheel) coupled to a wheel wheel (not shown). An outer ring 13 as a fixed ring, and a plurality of rolling elements 14 disposed in an annular space between the inner ring 12 and the outer ring 13. The center of rotation of the inner ring 12 coincides with an axis O passing through the center of the wheel hub bearing portion 11.

  On the outer peripheral surface of the outer ring 13, a plurality of outer ring projecting portions 13f are erected at different positions in the circumferential direction. A through hole is formed in each outer ring protrusion 13f protruding in the outer diameter direction. Each through-hole extends in parallel with the axis O, and the bolt 15 is passed from one side in the axis O direction. A shaft portion of each bolt 15 is screwed into a female screw hole formed in the front portion 38 f of the main body casing 38. The outer ring 13 is connected and fixed to the front portion 38f by a bolt 15 as a connecting member. The front portion 38 f is a casing wall portion that covers one end of the speed reduction portion 31 in the axis O direction. The outer ring 13 passes through the front portion 38f.

  The inner ring 12 is a cylindrical body that is longer than the outer ring 13 and is passed through the center hole of the outer ring 13. A coupling portion 12f is formed at one end portion in the axis O direction of the inner ring 12 protruding from the outer ring 13 to the outside of the in-wheel motor drive device 10. The coupling portion 12f is a flange and constitutes a coupling portion for coupling coaxially with a brake rotor and wheels (not shown). The inner ring 12 is coupled to the wheel at the coupling portion 12f and rotates integrally with the wheel.

  A plurality of rows of rolling elements 14 are arranged in the annular space between the inner ring 12 and the outer ring 13. The rolling element 14 is, for example, a steel ball. The outer peripheral surface of the central portion of the inner ring 12 in the direction of the axis O constitutes the inner raceway surface of the plurality of rolling elements 14 arranged in the first row. An inner race 12r is fitted to the outer periphery of the other end of the inner ring 12 in the axis O direction. The outer peripheral surface of the inner race 12r constitutes the inner race of the plurality of rolling elements 14 arranged in the second row. The inner peripheral surface at one end of the outer ring 13 in the direction of the axis O constitutes the outer raceway surface of the rolling elements 14 in the first row. An inner peripheral surface of the other end portion of the outer ring 13 in the axis O direction forms an outer raceway surface of the rolling elements 14 in the second row. A sealing material 16 is further interposed in the annular space between the inner ring 12 and the outer ring 13. The sealing material 16 seals both ends of the annular space to prevent intrusion of dust and foreign matter. The output shaft 37 of the speed reduction unit 31 is inserted into the center hole at the other end in the axis O direction of the inner ring 12 and is spline-fitted.

  The motor unit 21 includes a motor rotating shaft 22, a rotor 23, a stator 24, and a motor casing 25, and is sequentially arranged from the axis M of the motor unit 21 to the outer diameter side in this order. The motor unit 21 is an inner rotor / outer stator type radial gap motor, but may be of other types. For example, although not shown, the motor unit 21 may be an axial gap motor.

  An axis M serving as the rotation center of the motor rotation shaft 22 and the rotor 23 extends in parallel with the axis O of the wheel hub bearing portion 11. That is, the motor unit 21 is disposed offset from the axis O of the wheel hub bearing unit 11. For example, as shown in FIG. 1, the axis M of the motor unit is offset from the axis O in the vehicle front-rear direction, and specifically, is arranged in front of the vehicle with respect to the axis O.

  Returning to FIG. 2, both end portions of the motor rotating shaft 22 are rotatably supported by the back surface portion 38 b of the main body casing 38 and the motor casing cover 25 v of the motor portion 21 via the rolling bearings 27 and 28. . The motor casing 25 has a substantially cylindrical shape, and is integrally coupled to the back surface portion 38b of the main body casing 38 at one end in the axis M direction, and the other end in the axis M direction is sealed with a plate-like motor casing cover 25v.

  The speed reduction unit 31 includes an input shaft 32 s that is coaxially coupled to the motor rotation shaft 22 of the motor unit 21, an input gear 32 that is provided coaxially on the outer peripheral surface of the input shaft 32 s, a plurality of intermediate gears 33 and 35, An intermediate shaft 34 coupled to the center of the gears 33, 35, an output shaft 37 coupled coaxially with the inner ring 12 of the wheel hub bearing portion 11, an output gear 36 provided coaxially on the outer peripheral surface of the output shaft 37, and a plurality of these The main body casing 38 accommodates the gears and the rotating shaft. The main body casing 38 is also referred to as a speed reduction part casing because it forms an outline of the speed reduction part 31.

  The input gear 32 is an external helical gear. The input shaft 32s has a hollow structure, and one end portion in the axial direction of the motor rotation shaft 22 is inserted into the hollow input shaft 32s and is spline-fitted so as not to be relatively rotatable (the same applies to the following including serrations). The input shaft 32s is rotatably supported by the front portion 38f and the rear portion 38b of the main body casing 38 via rolling bearings 32m and 32n on both ends of the input gear 32.

  An axis N serving as the center of rotation of the intermediate shaft 34 of the deceleration unit 31 extends in parallel with the axis O. Both ends of the intermediate shaft 34 are rotatably supported by the front portion 38f and the back portion 38b of the main body casing 38 via bearings 34m and 34n. A first intermediate gear 33 and a second intermediate gear 35 are provided coaxially with the axis N of the intermediate shaft 34 at the center of the intermediate shaft 34. The first intermediate gear 33 and the second intermediate gear 35 are external helical gears, and the diameter of the first intermediate gear 33 is larger than the diameter of the second intermediate gear 35. The large-diameter first intermediate gear 33 is disposed on the other side in the axis N direction with respect to the second intermediate gear 35 and meshes with the small-diameter input gear 32. The small-diameter second intermediate gear 35 is disposed on one side in the axis N direction from the first intermediate gear 33 and meshes with the large-diameter output gear 36.

  The axis N of the intermediate shaft 34 is disposed above the axis O and the axis M as shown in FIG. Further, the axis N of the intermediate shaft 34 is disposed in front of the vehicle with respect to the axis O and behind the vehicle with respect to the axis M. The speed reduction unit 31 is a three-axis parallel shaft gear reducer having axes O, N, and M that are arranged at intervals in the vehicle front-rear direction and extend parallel to each other.

  Returning to FIG. 2, the output gear 36 is an external helical gear and is provided coaxially at the center of the output shaft 37. The output shaft 37 extends along the axis O. One end of the output shaft 37 in the direction of the axis O is inserted into the center hole of the inner ring 12 and is fitted so as not to be relatively rotatable. Such fitting is spline fitting or serration fitting. The other end of the output shaft 37 in the direction of the axis O is rotatably supported by the back surface portion 38b of the main body casing 38 via a rolling bearing 37n.

  An annular recess 36 c is formed on one end surface of the output gear 36 in the axis O direction. The annular recess 36c is centered on the axis O. An annular convex portion 38g that is received in the annular concave portion 36c is formed in the front portion 38f of the main body casing 38. A rolling bearing 37m is provided between the inner diameter side portion of the annular recess 36c and the inner diameter side portion of the annular projection 38g. As a result, the central portion in the direction of the axis O of the output shaft 37 is rotatably supported by the front portion 38f of the main body casing 38 via the rolling bearing 37m.

  The reduction gear 31 rotates the input shaft 32s by meshing the small-diameter drive gear and the large-diameter driven gear, that is, meshing the input gear 32 and the first intermediate gear 33, and meshing the second intermediate gear 35 and the output gear 36. Is decelerated and transmitted to the output shaft 37. The rotating elements from the input shaft 32 s to the output shaft 37 of the speed reduction unit 31 constitute a drive transmission path that transmits the rotation of the motor unit 21 to the inner ring 12.

  The main body casing 38 includes a cylindrical portion, and plate-shaped front portion 38f and back portion 38b that cover both ends of the cylindrical portion. The cylindrical portion covers the internal parts of the speed reducing portion 31 so as to surround the axes O, N, and M extending in parallel with each other. The plate-shaped front portion 38f covers the internal parts of the speed reducing portion 31 from one side in the axial direction. The plate-like back surface portion 38b covers the internal parts of the speed reducing portion 31 from the other side in the axial direction. The back surface portion 38 b of the main body casing 38 is a partition wall that is coupled to the motor casing 25 and partitions the internal space of the speed reduction portion 31 and the internal space of the motor portion 21. The motor casing 25 is supported by the main body casing 38 and protrudes from the main body casing 38 to the other side in the axial direction.

  The main body casing 38 defines an internal space of the speed reducing portion 31 and accommodates all the rotating elements (rotating shafts and gears) of the speed reducing portion 31 in the internal space. As shown in FIG. 1, the lower part of the main body casing 38 is an oil storage part 39. The oil reservoir 39 is disposed below the input gear 32. Lubricating oil that lubricates the motor unit 21 and the speed reduction unit 31 is stored in the oil storage unit 39 that occupies the lower part of the internal space of the main body casing 38.

  The input shaft 32s, the intermediate shaft 34, and the output shaft 37 are both supported by the above-described rolling bearing. The rolling bearings 32m, 34m, 37m, 32n, 34n, and 37n are radial bearings.

  The inner diameter portion of the output gear 36 is recessed in the direction of the axis O by the annular recess 36 c, and the plate thickness dimension of the inner diameter portion of the output gear 36 is made smaller than the tooth width of the output gear 36. The annular recess 36c accommodates the rolling bearing 37m. Thus, with respect to the position in the axis O direction, the output gear 36 and the rolling bearing 37m can be arranged so as to overlap each other, so that the dimension in the axis direction of the in-wheel motor drive device 10 can be reduced.

  The park lock mechanism 41 includes a park gear 42 as an engaged member, a park pole 43 as an engaging member, and a park cam 44 that operates the park pole 43.

  FIG. 3 is an enlarged view showing the park lock mechanism in the locked state according to the park lock mechanism according to the first embodiment of the present invention. FIG. 4 is a longitudinal sectional view corresponding to FIG. 3, and shows a state in which the park lock mechanism is cut along the flat surface IV-IV in FIG. 3 and the section is viewed in the direction of the arrow. The flat surface IV-IV includes the axis M. FIG. 5 is a cross-sectional view corresponding to FIG. 4 and shows a cross-section obtained by cutting the park lock mechanism along the flat surface VV in FIG. FIG. 6 is a cross-sectional view showing the park lock mechanism in the unlocked state.

  The park gear 42 as the engaged member is coaxially attached and fixed to the outer periphery of the input shaft 32s. As shown in FIG. 3, the park gear 42 includes a large number of gear teeth 42g such as an external gear, and a recess 42a defined by the tooth surface of the adjacent gear tooth 42g and the tooth bottom surface of the external gear. The concave portion 42a is formed between the gear teeth 42g and 42g adjacent in the circumferential direction, and has the same number as the many gear teeth 42g. In addition to this embodiment, as a modification (not shown), the park gear 42 may be coaxially attached and fixed to the outer periphery of the motor rotating shaft 22, the outer periphery of the output shaft 37, or the outer periphery of the intermediate shaft 34.

  The park pole 43 as an engagement member is a lever member that swings at the other end by using one end as a fulcrum, and is disposed adjacent to the park gear 42. The park pole 43 rotates between a lock position where the park pole 43 is engaged with the park gear 42 as shown in FIG. 3 and a lock release position where the park pole 43 is separated from the park gear 42 as shown in FIG. The park pole 43 is pivotally supported on the pivot 45 at one end.

  As shown in FIG. 2, the pivot 45 is erected on the inner wall surface of the main casing 38 and extends parallel to the axis M. One end serving as the base end is a position far from the park gear 42, and the other end serving as the free end is a position close to the park gear 42. As shown in FIG. 3, the park pole 43 has a front surface facing the park gear 42 and a back surface opposite to the park gear 42 between one end and the other end. On the front face of the other end of the park pole 43, a convex portion 43a that engages with the concave portion 42a of the park gear 42 is provided.

  A separation member 50 is provided on the park pole 43. The separating member is, for example, a torsion spring, and is wound around the pivot 45 to apply a biasing force in a direction to return to the unlocking position to the park pole 43.

  As shown in FIG. 3, when the park pole 43 is brought into the locked position and the convex portion 43a of the park pole 43 is engaged with the concave portion 42a of the park gear 42, the rotation of the park gear 42 is locked and the input shaft 32s cannot rotate. The drive transmission path from the motor rotation shaft 22 to the inner ring 12 through the speed reduction portion 31 is held unrotatable, and a locked state in which the wheels do not rotate is realized.

  On the contrary, as shown in FIG. 6, when the park pole 43 is set to the unlocked position and the convex portion 43a of the park pole 43 is not engaged with the concave portion 42a of the park gear 42, the rotation of the park gear 42 is allowed and the input shaft 32s is Rotation is possible. That is, the drive transmission path from the motor rotation shaft 22 through the speed reduction portion 31 to the inner ring 12 is allowed to rotate, and the wheels can be rotated.

  As shown in FIG. 1, a park cam 44 and a rotating shaft 46 are provided on the side opposite to the park gear 42 as viewed from the park pole 43. As shown in FIG. 2, the rotation shaft 46 is a support member that supports the park cam 44, is rotatably supported by the main body casing 38 at one end, and is coupled to the park cam 44 at the center. The other end of the rotation shaft 46 passes through the main body casing 38 and is coupled to a park lock operating member 47 provided outside the main body casing 38. The pivot shaft 46 and the pivot shaft 45 extend parallel to the axis M.

  When the rotation shaft 46 is passed through the through hole of the main body casing 38, a seal material 64 and a rolling bearing 65 are provided in the annular space between the through hole and the rotation shaft 46. The rolling bearing 65 is a radial bearing, for example, and supports the rotating shaft 46 so as to be rotatable. The sealing material 64 is, for example, an annular oil seal, and prevents foreign matter outside the in-wheel motor drive device 10 from entering the main body casing 38. A flange 46 f is provided inside the main body casing 38. The flange 46f is integrally formed with the rotation shaft 46, and one end of an urging member 63 described later is attached and fixed.

  As shown in FIG. 2, the park lock operating member 47 is attached to the outside of the main body casing 38. Further, the park lock operating member 47 is coupled to the rotating shaft 46 and is arranged behind the rotating shaft 46 (inward in the vehicle width direction) with reference to FIG.

  As shown in FIG. 2, the park lock operating member 47 is coupled to one end of the park lock wire 48. The park lock operating member 47 rotates the park cam 44 by rotating or rotating the rotating shaft 46 forward or backward by pushing or pulling the park lock wire. With the rotation of the park cam 44, the park pole 43 moves to either the locked position or the unlocked position.

  The other end (not shown) of the park lock wire 48 extends to the vehicle body. Specifically, it is connected to an operating device having an operation element such as a shift lever or an electric actuator for parking lock. The park lock wire 48 includes an outer tube 48t and an inner wire 48w. The inner wire 48w can be pushed and pulled. When the driver of the electric vehicle in the vehicle compartment space operates the shift lever, the inner wire 48w moves forward and backward in the outer tube 48t, the park lock operating member 47 is driven, and the park pawl 43 is locked and unlocked. Move to one of these.

  As a modification (not shown), the parking lock wire 48 is an electric wire, and the parking lock operating member 47 is an electric actuator incorporating a small motor. The drive portion of the electric actuator is directly connected to the rotation shaft 46 of the parking lock mechanism. May be combined.

  Referring to FIG. 1, the park cam 44 is a plate-like member having a rotation center, and is coupled to the rotation shaft 46 at the center. The park cam 44 has an annular central portion 44 b centered on the rotational shaft 46, and a rotational shaft passing through the central hole of the central portion 44 b, and the central portion 44 b is connected and fixed to the rotational shaft 46. The cam portion 44a protrudes from the center portion 44b in the outer diameter direction. The park cam 44 is a single part, and the cam portion 44a is a protrusion formed integrally with the central portion 44b.

  The park cam 44 is provided with an urging member 63. The urging member 63 is an elastic member such as a torsion spring, for example, and is wound around the rotation shaft 46 so that the park cam 44 is brought into contact with the back surface 43d of the other end of the park pole 43 as shown in FIGS. -In FIG. 7, it urges clockwise. As shown in FIG. 3, one end of the urging member 63 is attached and fixed to the flange 46 f of the rotating shaft 46. The other end of the urging member 63 is locked to the cam portion 44a.

  The park lock operating member 47 rotates the rotation shaft 46 to rotate the park cam 44 forward or backward. As a result, the cam portion 44a abuts against the back surface of the park pole 43 and presses the park pole 43, as shown in FIG. Alternatively, the cam portion 44 a is retracted from the back surface of the park pole 43 as shown in FIG. 6, and the park pole 43 is brought into the unlocked position by the urging force of the separating member 50.

  In the park lock mechanism 41, one end portions of the park gear 42, the park pole 43, the park cam 44, the pivot shaft 45, and the rotation shaft 46 are accommodated in the main body casing 38. That is, the park lock mechanism 41 of this embodiment is a built-in type.

  As shown in FIG. 2, the axial positions of the park gear 42, the park pole 43, and the park cam 44 overlap with the axial position of the intermediate gear 35. Specifically, the axial direction dimensions of the park gear 42, the park pole 43, and the park cam 44 are smaller than the tooth width of the intermediate gear 35 and fall within the tooth width dimension of the intermediate gear 35.

  As shown in FIGS. 4 and 5, the convex portion 43a includes a pair of plate members 43f and 43f, a pair of protrusions 43g and 43g, and a rolling member 43k. The pair of protrusions 43g and 43g protrude from the front surface of the park pole 43 and face each other. A round hole 43h is formed in each protrusion 43g. These two round holes 43h pass through the protruding portion 43g and are aligned and arranged to form a common axis.

  The rolling member 43k is a cylindrical or columnar roller. Both end portions of the rolling member 43k are received in the round holes 43h of the respective projecting portions 43g and are rotatably supported. The rotation axis of the rolling member 43k is substantially parallel to the axis M. That is, the protruding portion 43g is a support portion that rotatably supports the rolling member 43k.

  The plate member 43f is attached and fixed to both side surfaces of the park pole 43 by a connecting member such as a screw or welding. Each plate member 43f is disposed so as to overlap the protrusion 43g. For this reason, the round hole 43h is covered with the plate material 43f, and the rolling member 43k is prevented from coming out of the round hole 43h.

  The interval between the protrusions 43g is larger than the thickness of the park gear 42 in the direction of the axis M as shown in FIG. For this reason, the pair of protrusions 43 g and the pair of plate members 43 f are located on one side and the other side in the axis M direction relative to the park gear 42 and do not interfere with the park gear 42.

  The diameter of the central portion of the rolling member 43k is smaller than the interval between the gear teeth 42g of the park gear 42. Therefore, as shown in FIG. 5, the central portion of the rolling member 43 k can be completely fitted into the recess 42 a of the park gear 42.

  The protrusion 43g is integrally formed with a park pole main body extending from one end of the park pole 43 to the other end. In contrast, the plate member 43f and the rolling member 43k are separate members from the park pole body. That is, the park pole 43 is not a single part but an assembly.

  FIG. 7 is a cross-sectional view showing a state in which the rolling member 43k of the park pole 43 receives a reaction force from the park gear, and represents the cut surface by cutting the park lock mechanism 41 with a flat surface orthogonal to the axis M. For example, when an electric vehicle is parked on a slope with a large slope and the park lock mechanism 41 is operated, the gear teeth 42g of the park gear 42 abut against the rolling member 43k due to the slope angle of the slope and the reaction force from the wheels due to the vehicle weight. . As a result, a large reaction force acts on the rolling member 43k from the park gear 42.

  FIG. 8 is a schematic diagram illustrating a state in which the rolling member 43k is in rolling contact with the gear teeth 42g of the park gear 42 when the locked state is released. In FIG. 8, G1 to G3 represent a state in which the side surface (gear tooth 42g) of the recess 42a moves. K1 to K3 represent a state where the rolling member 43k moves. P <b> 1 to P <b> 3 represent a state in which the contact portion between the side surface of the recess 42 a and the rolling member 43 k moves. Among these, G1, K1, and P1 correspond to FIG. 7, and while the park pole 43 is set to the locked position, the rolling member 43k of K1 is given a reaction force from the side surface G1 at the contact point P1. Since the contact location P1 is a contact between the outer diameter surface of the rolling member 43k of K1 and the flat side surface G1, it is a line contact or a point contact.

  When the park pole 43 moves from the locked position (FIG. 7) to the unlocked position (FIG. 6), the rolling member 43k rolls in the direction indicated by the arrow C as shown in FIG. It moves in the direction shown by arrow D, such as K3 after passing through K2, and then exits from the recess 42a. The rolling member 43k of K2 is given a reaction force from the side surface G2 at the contact location P2. The rolling member 43k of K3 is given a reaction force from the corner of the gear tooth 42g at the contact point P3. The arrow D is an arc trajectory centered on the pivot 45.

  By the way, the in-wheel motor drive device 10 of 1st Embodiment is a vehicle motor drive device which drives a wheel with the motor part 21, and is provided with the park gear 42 which rotates with a wheel. Further, the in-wheel motor drive device 10 is engaged with the park gear 42 as shown in FIGS. 3 to 5 and FIG. 7, and is retracted from the locked position as shown in FIG. Thus, a park pole 43 is provided as an engaging member that is selectively set to one of the unlock positions that allow the park gear 42 to rotate. The park pole 43 includes a first rolling member 43k that is in rolling contact with the park gear 42, and a plate member 43f that rotatably supports the first rolling member 43k. The park gear 42 has a recess 42a, and engages with the park pole 43 by receiving a rolling member 43k in the recess 42a.

  According to the first embodiment, as shown in FIG. 7, even when the rolling member 43k receives a reaction force from the park gear 42 at the lock position of the park pole 43, the park pole 43 is moved to the lock release position. The rolling member 43k can be brought into rolling contact with the park gear 42 as indicated by an arrow C in FIG. Thus, the rolling member 43k moves away from the recess 42a while changing the reaction force by rolling, so that the projection 43a of the park pole 43 does not slide in contact with the gear teeth 42g and receives no frictional force from the park gear 42. The park pole 43 can move from the locked position toward the unlocked position with a small force.

  According to the park lock mechanism 41 of the first embodiment, when the electric vehicle is parked on a slope or the like and locked, the park pole 43 as an engaging member receives a reaction force from the park gear 42 as shown in FIG. Even when it is received, the locked state can be quickly and reliably released by the urging force of the separating member 50. Therefore, the electric vehicle parked on the slope can be started smoothly.

  The effect of the park lock mechanism 41 of the first embodiment will be described in comparison with the conventional example.

  FIG. 13 is a schematic diagram showing a state when the locked state is released in the conventional park lock mechanism. In FIG. 13, G <b> 1 to G <b> 3 represent the movement of the side surface (gear tooth 42 g) of the recess 42 a of the park gear. PK <b> 1 to PK <b> 3 represent a state where the convex portion 143 a of the park pole moves. The convex portion 143a is formed integrally with the free end of the park pole. PP1 to PP3 represent a state where the side surface of the concave portion 42a and the sliding contact portion of the convex portion 143a move. While the park pole is in the locked position, the convex portion 143a of PK1 is given a reaction force from the side surface G1 at the sliding contact point PP1. The contact point PP1 is a line contact or a point contact because it is a contact between the surface of the convex portion 143a and the corner of the gear tooth 42g.

  When the park pole 43 moves from the locked position to the unlocked position, the convex portion 143a moves from PK1 through PK2 to PK3 in the direction indicated by the arrow D, and retreats from the concave portion 42a while sliding on the park gear 42. The convex portion 143a is applied with a reaction force from the side surface G2 at the sliding contact point PP2. The rolling member 43k of K3 is given a reaction force from the side surface G3 at the sliding contact point PP3.

  Further, when the park pole 43 moves from the locked position toward the unlocked position, the convex portion 143a receives a frictional force that is the product of the reaction force described above and the friction coefficient of the sliding contact points PP1 to PP3. Therefore, in order for the park pole to move from the lock position toward the lock release position, a force larger than the frictional force of the sliding contact points PP1 to PP3 is required.

  According to the conventional park lock mechanism shown in FIG. 13, when the parked pole 143a receives a reaction force from the gear teeth 42g of the park gear by locking the electric vehicle on a slope or the like and locking it, It is difficult to release the state, and it may take time or become impossible to release.

  In the embodiment shown in FIGS. 5 to 7, both tooth surfaces of one gear tooth 42g (both side surfaces of one recess 42a) are made substantially parallel. As a modification, one gear tooth 42g may be formed into a tapered trapezoidal shape toward the outer diameter side. In other words, the both side surfaces of the recess 42a may be inclined so that the interval increases from the inner diameter side toward the outer diameter side. According to such a modification, the rolling member 43k rolls on the inclined side surface (the inclined tooth surface of the gear teeth 42g) of the recess 42a as shown in FIG. 8, so that the rotation becomes easy, and the park pole 43 is locked with a smaller force. It can move from the position toward the unlocked position.

  Also, according to the embodiment shown in FIGS. 4 to 7, the pair of protrusions 43 g are provided on both sides of the park pole 43 and face each other. The rolling member 43k is a cylindrical roller that is rotatably supported at both ends by a pair of protrusions 43g. As a result, the rolling member 43k can surely enter the recess 42a to realize the locked state. Further, since the rolling member 43k rolls smoothly while being in contact with the side surface of the recess 42a, the park pole 43 can be smoothly returned to the unlocked position only by the urging force of the separating member 50.

  Next, a second embodiment of the present invention will be described.

  FIG. 9 is an enlarged view showing the park lock mechanism 51 of the second embodiment in a locked state. FIG. 10 is a longitudinal cross-sectional view corresponding to FIG. 9, and shows a state where the park lock mechanism is cut along the line of the flat plane XX in FIG. 9 and the cross section is viewed in the direction of the arrow. The flat surface XX includes the axis M. FIG. 11 shows a cross section of the parking lock mechanism 51 taken along the line of the flat surface IX-IX in FIG. FIG. 12 is a cross-sectional view showing the park lock mechanism in the unlocked state. The same components as those in the first embodiment described above are denoted by the same reference numerals, description thereof is omitted, and different configurations will be described below. The park lock mechanism 51 of the second embodiment has basically the same configuration as the park lock mechanism 41 shown in FIG. 5, except that the cam portion 44a includes a second plate member 44f, a second protrusion 44g, and a second projection portion 44g. 2 rolling members 44k are included. That is, the park cam 44 of the second embodiment is different from the first embodiment in that it is not a single component but an assembly.

  The pair of second protrusions 44g and 44g protrude from the central portion 44b of the park cam 44 and face each other. A second round hole 44h is formed in each second protrusion 44g. These two second round holes 44h pass through the second projecting portion 44g and are aligned to form a common axis.

  The second rolling member 44k is a cylindrical or columnar roller. Both end portions of the second rolling member 44k are received in the second round holes 44h of the second projecting portions 44g and are rotatably supported. The rotation axis of the second rolling member 44k is substantially parallel to the axis M. That is, the second protrusion 44g is a second support portion that rotatably supports the second rolling member 44k.

  The second plate material 44f is attached and fixed to both surfaces of the park cam 44 by a connecting member such as a screw or by welding. Each of the second plate members 44f is disposed so as to overlap the second protrusion 44g. For this reason, the second round hole 44h is covered with the second plate material 44f, and the second rolling member 44k is prevented from coming out of the second round hole 44h.

  The interval between the second protrusions 44g is larger than the dimension of the rear surface 43d of the park pole 43 in the axis M direction as shown in FIG. For this reason, the pair of second protrusions 44 g and the pair of second plate members 44 f are located on one side and the other side in the axis M direction with respect to the rear surface 43 d of the park pole 43 and do not interfere with the park pole 43.

  The second protrusion 44g is formed integrally with the central portion 44b. In contrast, the second plate member 44f and the second rolling member 44k are separate members from the central portion 44b. That is, the park cam 44 is not a single part but an assembly.

  The central portion of the second rolling member 44k is in rolling contact with the back surface 43d of the park pole 43. Specifically, when shifting from the unlocked state shown in FIG. 12 to the locked state shown in FIG. 11, the park cam 44 rotates forward in the clockwise direction on the paper surface, and the second rolling member 44k is connected to one end of the park pole 43 (the pivot axis). It rolls in contact with the back surface 43d from the (45 side) toward the other end (the convex portion 43a side). As a result, the park pole 43 moves from the unlocked position to the locked position.

  On the contrary, when shifting from the locked state shown in FIG. 11 to the unlocked state shown in FIG. 12, the park cam 44 reversely rotates counterclockwise on the paper surface, and the second rolling member 44k is connected to the other end (convex portion) of the park pole 43. It rolls in contact with the back surface 43d from one side (43a side) toward one end (on the pivot 45 side). As a result, the park pole 43 moves from the lock position (FIG. 11) to the lock release position (FIG. 12).

  By the way, according to the park lock mechanism 51 of the second embodiment, the rotation shaft 46, the center portion 44b having the rotation shaft 46 as the rotation center, and the cam portion 44a protruding from the center portion 44b to the outer diameter side are provided. In addition, the cam portion 44a further includes a park cam 44 that presses the park pole 43 toward the lock position (FIG. 9) by turning around the turning shaft 46, and the cam portion 44a is in rolling contact with the park pole 43. The rolling member 44k and the 2nd projection part 44g which supports the 2nd rolling member 44k rotatably are included. According to the second embodiment, since the cam portion 44a is in rolling contact with the park pole 43, the park cam 44 can move the park pole 43 with a smaller force than in the first embodiment. Therefore, the park lock operating member 47 can be further reduced in size. In particular, when the park lock actuating member 47 is an electric actuator, there is an actual advantage that it contributes to a reduction in output, power saving, size reduction, and weight reduction.

  In the first embodiment, since the cam portion 44a is in sliding contact with the park pole 43, a frictional force is generated at the contact location. Therefore, the park lock operating member 47 must rotate the park cam 44 with a torque larger than the frictional force, and it is necessary to increase the pushing force of the park lock wire connected to the park lock operating member.

  Further, according to the park lock mechanism 51 of the second embodiment, the second protrusions 44g that rotatably support the second rolling member 44k are provided on both sides of the park cam 44 and face each other, and the second rolling member 44k is These are cylindrical rollers that are rotatably supported at both ends by a pair of second protrusions 44g. Thereby, the center part of the 2nd rolling member 44k rolls contacting the park pole 43, and the contact which the 2nd rolling member 44k rolls smoothly is realizable.

  Moreover, the in-wheel motor drive device 10 of 1st and 2nd embodiment is the inner ring | wheel 12 as a hub wheel including the coupling | bond part 12f for couple | bonding with a wheel, the outer ring | wheel 13 as a fixed wheel, and the inner ring | wheel 12 and the outer ring | wheel 13 A wheel hub bearing 11 having a plurality of rolling elements 14 interposed in the annular gap and rotatably supporting the inner ring 12 by the outer ring 13, a motor part 21 for driving the inner ring 12, and the motor part 21 to the inner ring 12. A parking lock mechanism 41 or a parking lock mechanism 51 provided in the drive transmission path, a park gear 42, a park pole 43 as an engaging member, and a main body casing 38 that houses the drive transmission path are provided.

  According to this embodiment, in the pair of left and right in-wheel motor drive devices 10 that respectively drive the left and right wheels of the electric vehicle, unlocking of the left and right wheel park lock mechanisms can be realized simultaneously. Therefore, there is no possibility that the lock release timing of the park lock mechanism is shifted between the left and right wheels as in the prior art, and normal running of the electric vehicle is realized.

  Although the embodiments of the present invention have been described with reference to the drawings, the present invention is not limited to the illustrated embodiments. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention. For example, each gear may be another type (spur gear, helical gear, helical gear, etc.), and the rolling bearing may be a sliding bearing.

  The park lock mechanism according to the present invention is advantageously used in electric vehicles and hybrid vehicles.

10 in-wheel motor drive, 11 wheel hub bearing,
12 inner ring (hub ring), 12f coupling part, 13 outer ring (fixed ring),
14 rolling elements, 21 motor section, 22 motor rotating shaft,
31 Reduction part (drive transmission path), 38 Main body casing,
41, 51 Park lock mechanism, 42 Park gear,
42a recess, 42g gear teeth, 43 park pole,
43a convex part, 43d back surface, 43f board material,
43g protrusion (first support part), 43h round hole,
43k (first) rolling member, 44 park cam,
44a cam portion, 44b center portion, 44f second plate material,
44g 2nd protrusion (2nd support part), 44g 2nd protrusion,
44h second round hole, 44k second rolling member, 45 pivot,
46 rotating shaft, 47 park lock actuating member,
48 wire for park lock, 50 separating member, 63 biasing member,
G1, G2, G3 side surface of the recess (tooth surface of gear teeth),
M, N, O axis, P1, P2, P3, PP1, PP2, PP3 Sliding contact points.

Claims (7)

A park gear that is provided in a vehicle motor drive device that drives a wheel with a motor and rotates together with the wheel;
An engagement member that is selectively engaged with either the lock position that engages with the park gear and prohibits rotation of the park gear and the unlock position that retreats from the lock position and allows rotation of the park gear. Prepared,
The engagement member includes a first rolling member that is in rolling contact with the park gear, and a first support portion that rotatably supports the first rolling member,
The park gear has a recess, and the park gear is engaged with the engagement member by receiving the first rolling member in the recess. The recess is oriented in the outer diameter direction of the park gear,
2. The park lock mechanism according to claim 1, wherein both side surfaces of the concave portion are inclined so that an interval increases from an inner diameter side toward an outer diameter side. The first support portions are provided on both sides of the engagement member and face each other.
The park lock mechanism according to claim 1 or 2, wherein the first rolling member is a cylindrical roller whose both ends are rotatably supported by a pair of the first support portions.   A center portion having a rotation center and a cam portion protruding from the center portion toward the outer diameter side, and the engagement member is pressed toward the lock position by the cam portion by rotation around the rotation center. The park lock mechanism according to any one of claims 1 to 3, further comprising a park cam.   5. The park lock according to claim 1, wherein the cam portion includes a second rolling member that is in rolling contact with the engaging member, and a second support portion that rotatably supports the second rolling member. mechanism. The second support portions are provided on both sides of the park cam and face each other.
The park lock mechanism according to claim 5, wherein the second rolling member is a cylindrical roller whose both ends are rotatably supported by a pair of the second support portions. A hub wheel including a coupling portion for coupling with a wheel, a fixed wheel, and a plurality of rolling elements interposed in an annular gap between the hub wheel and the fixed wheel, the hub wheel being rotatable by the fixed wheel A supporting wheel hub bearing,
A motor unit for driving the hub wheel;
The park lock mechanism according to any one of claims 1 to 6, provided in a drive transmission path from the motor unit to the hub wheel,
An in-wheel motor drive device comprising: the park gear, the engagement member, and a casing that houses the drive transmission path.

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