WO2012164647A1

WO2012164647A1 - Vehicle torque limiter device

Info

Publication number: WO2012164647A1
Application number: PCT/JP2011/062245
Authority: WO
Inventors: 充孝土田; 康広林
Original assignee: トヨタ自動車株式会社
Priority date: 2011-05-27
Filing date: 2011-05-27
Publication date: 2012-12-06

Abstract

Provided is a vehicle torque limiter device that is provided between an electric motor and a driving wheel, wherein the limit torque can easily be secured. Because the frictional engaging element (98) of the torque limiter device (24) can be disposed towards that outer circumference up to a position in the radial direction that is adjacent to the rotor (74) (rotor core (78)) of the electric motor (M1), a large effective disc (102) radius r can be secured. Consequently, the necessary limit torque Tlm can be obtained without increasing the number of discs (102), increasing disc (102) thickness, etc. And since the frictional engaging element (98) is disposed on the inside of the coil end (76), the space formed inside the coil end (76) is used effectively and the length of the power transmission device (10) in the axial direction can be shortened as a result of the overlap of the frictional engaging element (98) and the coil end (76) in the radial direction.

Description

Torque limiter device for vehicle

The present invention relates to a torque limiter device provided in a vehicle.

2. Description of the Related Art A vehicle equipped with a torque limiter device that connects a power transmission path between an electric motor and drive wheels so as not to be connected or disconnected is known. The torque limiter device is mainly configured to include a friction engagement element and a disc spring, and when a torque exceeding a preset limiter torque is input, slipping occurs in the friction engagement element. The transmission of torque exceeding the limiter torque is prevented. For example, the torque limiter mechanism described in Patent Document 1 and Patent Document 2 is an example. The torque limiter mechanism 56 of Patent Document 1 is disposed on the inner periphery of the rotor 52 of the first electric motor MG1, and connects the rotor 52 of the electric motor and the sun gear S0 of the power distribution mechanism 16 so that they cannot be connected or disconnected. Further, the torque limiter mechanism 31 of Patent Document 2 is disposed on the inner peripheral side of the rotor 15c of the motor generator 15 (electric motor), and the rotor 15c of the motor generator 15 and the sun gear 27 of the power distribution mechanism 17 cannot be connected or disconnected. It is linked to.

JP 2010-162969 A JP 2010-254230 A JP 2003-191760 A

Incidentally, the torque limiter devices of Patent Document 1 and Patent Document 2 are both disposed on the inner peripheral side of the rotor of the electric motor. When the torque limiter device is arranged at such a position, the effective diameter of the friction material of the friction engagement element is shortened. Therefore, in the torque limiter device, in order to obtain a necessary limit torque, it is necessary to increase the number of friction materials of the friction engagement elements or increase the pressing load of the disc spring. However, increasing the number of friction materials leads to an increase in cost and weight. Further, when the disc spring load is increased, it is necessary to give the friction engagement element strength that can cope with the disc spring load. For example, the plate thickness of the friction plate is increased, resulting in an increase in cost and weight. It leads to increase.

The present invention has been made against the background of the above circumstances. The object of the present invention is to provide a friction limiter for a friction material in a vehicle torque limiter provided in a power transmission path between an electric motor and a drive wheel. It is an object of the present invention to provide a torque limiter device for a vehicle that can secure a necessary limiter torque without increasing the number of sheets and increasing the thickness of a friction plate.

In order to achieve the above object, the gist of the invention according to claim 1 is that: (a) a torque limiter device for a vehicle provided in a power transmission path between an electric motor and drive wheels; The torque limiter device includes an end plate that rotates integrally with the rotor of the electric motor, a power transmission member, and a friction engagement element that connects the end plate and the power transmission member so that they cannot be connected or disconnected. The element is arranged on the inner peripheral side of the coil end of the electric motor, and (d) the rotor of the electric motor is supported by the case via the power transmission member.

In this way, since the frictional engagement element of the torque limiter device can be arranged on the outer peripheral side to the position adjacent to the rotor of the electric motor in the radial direction, a large effective diameter of the friction material can be secured. Therefore, the necessary limiter torque can be obtained without increasing the number of friction materials or the thickness of the friction plate. Further, since the friction engagement element is arranged on the inner peripheral side of the coil end, the space formed on the inner peripheral side of the coil end is effectively utilized, and the friction engagement element and the coil end overlap in the radial direction. Accordingly, the axial length of the device is also shortened.

Preferably, the end plate is provided on an inner peripheral side with respect to the friction engagement element, and a disc spring that presses the friction engagement element includes the friction engagement element and the power transmission member in the axial direction. Is inserted in a preloaded state. In this way, the end plate can be shared as a constituent member of the rotor and a constituent member of the torque limiter device, so that an increase in the number of parts is prevented and the axial length of the device is also shortened. .

Preferably, the end plate is provided on the outer peripheral side of the friction engagement element, and a disc spring that presses the friction engagement element is disposed between the friction engagement element and the rotor in the axial direction. Is inserted in a preloaded state. In this way, since the electromagnetic steel plate constituting the rotor is pressed in the axial direction by the disc spring, the member for fixing the electromagnetic steel plate can be eliminated, and the apparatus is simplified.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram for explaining a vehicle power transmission device according to a first embodiment to which the present invention is applied. It is sectional drawing showing the range equivalent to the II section (one-dot chain line) of Drawing 1 containing the principal part of the power transmission device for vehicles of Drawing 1, ie, a torque limiter device. It is sectional drawing for demonstrating the periphery structure of the torque limiter apparatus of the power transmission device for hybrid vehicles which is the other Example of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following embodiments, the drawings are appropriately simplified or modified, and the dimensional ratios, shapes, and the like of the respective parts are not necessarily drawn accurately.

FIG. 1 is a skeleton diagram for explaining a hybrid vehicle power transmission device 10 (hereinafter referred to as “power transmission device 10”) to which the present invention is applied.

In FIG. 1, a power transmission device 10 is interposed between an engine 14 which is an internal combustion engine such as a gasoline engine or a diesel engine and a drive wheel 40, and a driving force from the engine 14 is applied to the drive wheel 40. A transaxle to transmit. The power transmission device 10 has a transaxle (T / A) case 12 (hereinafter referred to as “case 12”) as a non-rotating member attached to the vehicle body. In the case 12, the first axis RC1 is provided. In order from the engine 14 side, a damper 16 operatively connected to an output shaft (for example, a crankshaft) of the engine 14 is connected to the engine 14 via the damper 16 and is rotated by the engine 14. Input shaft 18, first drive gear 20 as an output rotating member supported so as to be rotatable relative to input shaft 18 on the outer periphery side of input shaft 18, planetary gear device 22 functioning as a power distribution mechanism, and first electric motor M1 And a drive wheel 40 are provided with a torque limiter device 24 provided in the power transmission path and a first electric motor M1. Further, the power transmission device 10 is connected to the first driven gear 26, the first counter gear device 28, and the first driven gear 26 that mesh with the first drive gear 20 in the case 12 via the first counter gear device 28. A second drive gear (differential drive gear) 30, a second counter gear device 32, and a second electric motor M2 connected to the second drive gear 30 via the second counter gear device 32 are parallel to the first axis RC1. And a differential gear device (final reduction gear) 36 having a second driven gear (diffractive driven gear) 34 that meshes with the second drive gear 30.

The power transmission device 10 is, for example, placed in front of a front wheel drive, that is, an FF (front engine / front drive) type vehicle 6, and is preferably used to drive the drive wheels 40. In the power transmission device 10, the power of the engine 14 is generated by the damper 16, the input shaft 18, the planetary gear device 22, the first drive gear 20, the first driven gear 26, the first counter gear device 28, the second drive gear 30, and the differential. It is transmitted to the pair of drive wheels 40 through the gear device 36 and the pair of axles 38 in order.

The damper 16 is a damper used in a general vehicle, and is interposed between the engine 14 and the input shaft 18. The damper 16 transmits torque from one of the engine 14 and the input shaft 18 to the other and the engine. 14 absorbs pulsation caused by torque fluctuations and the like.

The first counter gear device 28 includes a first countershaft 42 that is parallel to the second axis RC2, a first gear 44 that is coaxially connected to the first driven gear 26, and a first gear 44 that meshes with the first gear 44. A second gear 46 connected to the countershaft 42, a third gear 48 connected to the first countershaft 42 and rotating integrally with the second gear 46, meshed with the third gear 48, and the second drive gear 30. A fourth gear 50 connected coaxially therewith is provided. The first counter gear device 28 thus configured decelerates the rotation from the first driven gear 26 and transmits it to the second drive gear 30.

The second counter gear device 32 includes a second countershaft 52 parallel to the second axis RC2, a fifth gear 54 coaxially connected to the second electric motor M2, and a second gear meshing with the fifth gear 54. A sixth gear 56 connected to the countershaft 52, a seventh gear 58 connected to the second countershaft 52 and rotating integrally with the sixth gear 56, meshed with the seventh gear 58, and the second drive gear 30. An eighth gear 60 connected coaxially thereto is also provided. The second counter gear device 32 configured in this manner decelerates the rotation from the second electric motor M <b> 2 and transmits it to the second drive gear 30.

FIG. 2 is a cross-sectional view showing a range corresponding to a main part of the power transmission device 10, that is, a II portion (a chain line) in FIG. 1 including the torque limiter device 24. As shown in FIG. 2, a sun gear S1 and a first electric motor M1 (electric motor) of a planetary gear device 22 that can rotate around the first axial center RC1 are arranged in series. The transmission member) and the torque limiter device 24 are connected so as to be able to transmit power. Further, the first electric motor M1 and the planetary gear device 22 (only the sun gear S1 is described) are partitioned by the partition wall 12a of the case 12 that is a non-rotating member, so that the gear chamber in which the planetary gear device 22 is accommodated in the case 12. And the MG chamber in which the 1st electric motor M1 is accommodated is formed.

The sun gear S1 of the planetary gear unit 22 is formed in a cylindrical shape, and the outer peripheral teeth of the sun gear S1 are formed at the outer peripheral end of the engine side in the axial direction. Moreover, the outer peripheral tooth for spline fitting with the power transmission shaft 70 is formed in the other of the axial direction.

The first electric motor M1 includes a stator 72 fixed to the case 12 so as not to rotate by bolting or the like, a rotor 74 provided on the inner peripheral side of the stator 72 and rotatable about the first axis RC1, a stator 72 and a coil end 76 protruding in the axial direction from both ends.

The rotor 74 includes a rotor core 78 composed of a plurality of disk-shaped electromagnetic steel plates stacked in the axial direction on the inner peripheral side of the stator 76, and a cylindrical shape that rotates integrally with the rotor core 78 on the inner peripheral portion of the rotor core 78. A disk-shaped first end plate 82 (corresponding to the end plate of the present invention) and a second end plate 84 which are disposed adjacent to both ends of the rotor shaft 80 in the axial direction of the rotor core 78 and sandwich the rotor core 78 therebetween. It has.

The rotor core 78 is formed with a through hole 79 penetrating the rotor core 78 in the axial direction, and the second end plate 84 is similarly penetrated through the second end plate 84 in the axial direction. Is formed. A thrust bearing 87 is inserted between the rotor shaft 80 and the sun gear S1, and supports the rotation shafts of each other so as to be relatively rotatable. A lubricating oil supply oil passage 89 is formed in the rotor shaft 80 in parallel with the first axis RC1. The lubricating oil flowing through the lubricating oil supply oil passage 89 is supplied to the friction engagement element 98 after lubricating the thrust bearing 87 and the bearing 88. Further, the lubricating oil that has lubricated the friction engagement element 98 is supplied to the coil end 76 through the coil end 76 disposed on the outer peripheral side of the friction engagement element 98 or through

holes

79 and 85. That is, the lubricating oil also functions as a cooling oil for the coil end 76.

The power transmission shaft 70 connects the gear chamber and the MG chamber through the inner peripheral side of the partition wall 12a of the case 12, and has a cylindrical shape in which the diameter of the first electric motor M1 (MG chamber side) is increased in the axial direction. This member is supported by the case 12 via a bearing 86 so as to be relatively rotatable. Here, one end in the axial direction of the rotor shaft 80 of the first electric motor M1 is supported by the bearing 88 so as to be relatively rotatable with respect to the power transmission shaft 70, and the other end in the axial direction is relatively rotatable with respect to the case 12 by the bearing 90. It is supported by. That is, one end of the rotor shaft 80 in the axial direction is supported by the case 12 via the power transmission shaft 70 so as to be relatively rotatable.

The power transmission shaft 70 has a cylindrical small diameter cylindrical portion 92 in which spline teeth for spline fitting with the sun gear S1 are formed at one end on the outer periphery in the axial direction, and the other end portion of the small diameter cylindrical portion 92 in the radial direction. A disk-shaped enlarged diameter portion 94 that extends, and a large-diameter cylindrical portion 96 that extends from the outer peripheral end portion of the enlarged diameter portion 94 toward the first electric motor M1 in parallel with the first axis RC1.

A friction engagement element 98 (to be described later) that constitutes the torque limiter device 24 is provided between the large-diameter cylindrical portion 96 and the first end plate 82 in the radial direction. Specifically, the friction engagement element 98 is disposed in a space surrounded by the inner periphery of the large-diameter cylindrical portion 96 and the outer periphery of the first end plate 82.

The torque limiter device 24 includes a first end plate 82, a power transmission shaft 70, a friction engagement element 98, and a disc spring 100, and the first end plate 82 and the power transmission shaft are formed by the friction engagement element 98. 70 is connected so that it cannot be connected or disconnected.

The friction engagement element 98 includes a disk 102 that is a ring-shaped friction plate, a pair of ring-shaped flanges 104 and 105 that are adjacent to both ends of the disk 102, and the first motor M1 side in the axial direction. The flange 105 and the adjacent snap ring 106 are provided.

The disk 102 is spline-fitted to the outer peripheral portion of the first end plate 82 so as not to rotate relative to the first end plate 82 and is movable in the axial direction, and is rotated together with the first end plate 82, that is, the rotor 74. The flanges 104 and 105 are spline-fitted to the inner peripheral portion of the large-diameter cylindrical portion 96 so as not to be relatively rotatable and movable in the axial direction, and are rotated together with the power transmission shaft 70. The snap ring 106 is fitted into an annular groove formed in the inner peripheral portion of the large-diameter cylindrical portion 96, and is prevented from moving in the axial direction. Therefore, the axial movement of the flange 105 adjacent to the snap ring 106 is restricted by the snap ring 106.

The disc spring 100 is inserted in the axial direction between the friction engagement element 98 and the enlarged diameter portion 94 of the power transmission shaft 70 in a preloaded state set in advance. Specifically, one end of the disc spring 100 is in contact with the enlarged diameter portion 94 and the other end is in contact with the flange 104 of the friction engagement element 98. The disc spring 100 always presses the flange 104 toward the snap ring 106 with a preset preload (disc spring load). Here, since the movement of the flange 105 in the axial direction is restricted by the snap ring 106, the disc spring load F of the disc spring 100 and the disc 102 and the flanges 104, 105 are between the disc 102 and the flanges 104, 105. A friction force based on the friction coefficient μ is generated. Based on this frictional force and the effective diameter r of the disk 102, the limiter torque Tlm of the torque limiter device 24 is set.

The limiter torque Tlm is set by appropriately adjusting the disc spring load F of the disc spring 100, the friction coefficient μ of the disc 102 (friction material), and the effective diameter r of the disc 102. For example, the limiter torque Tlm increases as the disc spring load F increases, the limiter torque Tlm increases as the friction coefficient μ increases, and the limiter torque Tlm increases as the effective diameter r of the disk 102 increases.

As shown in FIG. 2, the torque limiter device 24 (friction engagement element 98) of the present embodiment is disposed in the MG chamber and on the inner peripheral side of the coil end 76 of the first electric motor M1. Conventionally, a friction engagement element has been arranged on the inner peripheral side of the rotor of the electric motor. On the other hand, in the present embodiment, the friction engagement element 98 is disposed on the inner peripheral side of the coil end 76, so that the friction engagement element 98 is adjacent to the rotor 74 (rotor core 78) of the electric motor M1 in the radial direction. Since it can arrange | position to an outer peripheral side to the matching position, compared with the past, the effective diameter r of the disk 102 becomes large, and ensuring of the required limiter torque Tlm becomes easy. In addition, a space is conventionally formed in the inner peripheral portion of the coil end 76, and the space is effectively utilized by arranging the torque limiter device 24 in this space, so that the axial length of the power transmission device 10 is increased. Is shortened.

As described above, according to the present embodiment, the friction engagement element 98 of the torque limiter device 24 can be disposed on the outer peripheral side to a position adjacent to the rotor 74 (rotor core 78) of the electric motor M1 in the radial direction. A large effective diameter r of the disk 102 can be secured. Therefore, the necessary limiter torque Tlm can be obtained without increasing the number of disks 102 or increasing the thickness of the disks 102. Further, since the friction engagement element 98 is disposed on the inner peripheral side of the coil end 76, the space formed on the inner peripheral side of the coil end 76 is effectively utilized, and the friction engagement element 98 and the coil end 76 are separated. The length of the power transmission device 10 in the axial direction can be shortened as it overlaps in the radial direction.

Further, according to the present embodiment, the first end plate 82 is provided on the inner peripheral side with respect to the friction engagement element 98, and the disc spring 100 that presses the friction engagement element 98 includes the friction engagement element in the axial direction. 98 and a power transmission shaft 70 are inserted in a preloaded state. In this way, the first end plate 82 is shared as a member of the rotor 74 and a constituent member of the torque limiter device 24, so that an increase in the number of components is prevented and the axial length of the power transmission device 10 is prevented. Also shortened.

Further, according to the present embodiment, since the lubricating oil supplied to the friction engagement element 98 is also used as the cooling oil for the coil end 76, the lubricating oil can be effectively used.

Further, according to the present embodiment, since the torque limiter device 24 is provided between the first electric motor M1 and the power transmission shaft 70, it is not necessary to provide the torque limiter device in the damper device that absorbs the torque fluctuation of the engine. Since the torque limiter device provided in the damper device is a dry torque limiter device, the performance is likely to deteriorate due to the external environment (such as adhesion of foreign matter). On the other hand, since the torque limiter device 24 of the present embodiment is a wet torque limiter device, performance degradation due to the external environment is suppressed.

Next, another embodiment of the present invention will be described. In the following description, the same reference numerals are given to portions common to the above-described embodiments, and the description is omitted.

FIG. 3 is a cross-sectional view for explaining a peripheral structure of a torque limiter device 202 of a hybrid vehicle power transmission device 200 (hereinafter referred to as “power transmission device 200”) according to another embodiment of the present invention. This corresponds to the cross-sectional view of FIG. 2 and the II part (dashed line) of FIG. When the torque limiter device 202 of the present embodiment is compared with the torque limiter device 24 described above, the structures of the rotor shaft 201, the power transmission shaft 204 (power transmission member), the end plate 206, and the friction engagement element 205 are different. .

The rotor shaft 201 is supported by the case 12 at one end in the axial direction and supported by the case 12 through the power transmission shaft 204 at the other end in the axial direction. Specifically, one axial direction of the rotor shaft 201 is supported by the case 12 via the bearing 90 so as to be relatively rotatable, and the other axial direction is supported by the case 12 via the bearing 88, the power transmission shaft 204 and the bearing 86. It is supported for relative rotation. Further, a flange portion 201 a is formed on the outer peripheral surface of the rotor shaft 201, and movement in the axial direction is restricted by the rotor core 78 being in direct contact with the flange portion 201. Furthermore, a communication hole 201b is formed to communicate the lubricating oil supply oil passage 89 formed on the inner periphery of the rotor shaft 201 with the outer peripheral surface. Therefore, when the rotor shaft 201 rotates, the lubricating oil in the lubricating oil supply oil passage 89 is discharged in the outer circumferential direction by centrifugal force through the communication hole 201b. After the discharged lubricating oil lubricates the friction system element 205, the coil end 76 is further cooled.

Also in this embodiment, the torque limiter device 202 is provided on the inner peripheral side of the coil end 76. The torque limiter device 202 includes a power transmission shaft 204, an end plate 206, a friction engagement element 205, and a disc spring 207, and the end plate 206 and the power transmission shaft 204 are disconnected by the friction engagement element 205. It is inaccessible.

The power transmission shaft 204 has a cylindrical small-diameter cylindrical portion 208 in which spline teeth for spline fitting with the sun gear S1 are formed at one end of the outer periphery in the axial direction, and a disk shape extending in the radial direction from the small-diameter cylindrical portion 208. , And a large-diameter cylindrical portion 212 that extends in the axial direction from the outer peripheral end portion of the enlarged-diameter portion 94 toward the first electric motor M1. The enlarged diameter portion 210 of the present embodiment extends to the middle portion of the rotor core 78 in the radial direction.

The end plate 206 of this embodiment is provided on the outer periphery of the rotor core 78. The end plate 206 has a cylindrical cylindrical portion 214 provided adjacent to the outer peripheral surface of the rotor core 78, and a first annular plate-shaped portion extending from one axial end of the cylindrical portion 214 toward the inner peripheral side. A stopper portion 216 and an annular plate-shaped second stopper portion 218 extending from the other axial end of the cylindrical portion 214 toward the inner peripheral side are provided.

The cylindrical portion 214 of the end plate 206 is inserted in a gap formed between the rotor 74 and the stator 72, and is arranged in a state where the inner peripheral surface is in contact with the outer peripheral surface of the rotor core 78. Further, a first stopper portion 216 extending from the end portion on the bearing 90 side toward the inner peripheral side in the axial direction of the cylindrical portion 214 is formed, and one end of the rotor core 78 abuts on the first stopper 216, The movement of the rotor core 78 in the axial direction is restricted. The side of the cylindrical portion 214 where the frictional engagement element 205 is disposed is further extended in the axial direction toward the partition wall 12a (gear chamber side), and extends to the inner peripheral side at the extended end portion. Two stopper portions 218 are formed.

The friction engagement element 205 is provided between the rotor core 78 and the second stopper portion 218 in the axial direction. The friction engagement element 205 is provided on the inner peripheral side of the cylindrical end 204 of the coil end 76 and the end plate 206 in the radial direction and on the outer peripheral side of the large-diameter cylindrical portion 212.

The friction engagement element 205 includes a disk 220 that is an annular plate-like friction plate, and a pair of annular plate-

like flanges

222 and 223 that are adjacent to both ends of the disk 220. The disc 220 is spline-fitted to the outer peripheral surface of the large-diameter cylindrical portion 212 of the power transmission shaft 204 so as not to be relatively rotatable and to be movable in the axial direction. The

flanges

222 and 223 are spline-fitted to the inner peripheral surface extending toward the partition wall 12a of the cylindrical portion 214 so as not to be relatively rotatable and movable in the axial direction. The axial movement of the flange 223 adjacent to the second stopper portion 218 in the axial direction is restricted by the second stopper portion 218.

The disc spring 207 is inserted between the rotor core 78 and the friction engagement element 205 in the axial direction in a preloaded state set in advance. Specifically, one end of the disc spring 207 contacts the flange 222 and the other end contacts the rotor core 78. Note that the outer peripheral side of the disc spring 207 is spline-fitted to inner peripheral teeth formed on the inner peripheral surface of the cylindrical portion 214. The disc spring 207 presses the flange 222 toward the second stopper portion with a preload (disc spring load F) set in advance, and presses the rotor core 78 toward the first stopper portion 216. ing. Here, since the movement in the axial direction is restricted by the first stopper 218, the disc spring load F of the disc spring 207 and the friction coefficient between the disc 220 and the

flanges

222 and 223 between the disc 220 and the

flanges

222 and 223. A frictional force based on μ is generated. Based on this frictional force and the effective diameter r of the disk 220, the limiter torque Tlm of the torque limiter device 202 is set.

As shown in FIG. 3, the torque limiter device 202 of the present embodiment is disposed in the MG chamber and on the inner peripheral side of the coil end 76 of the first electric motor M1. Conventionally, a friction engagement element has been arranged on the inner peripheral side of the rotor of the electric motor. On the other hand, in the present embodiment, the friction engagement element 205 is disposed on the inner peripheral side of the coil end 76, so that the friction engagement element 205 is adjacent to the rotor 74 (rotor core 78) of the electric motor M1 in the radial direction. Since it can arrange | position to an outer peripheral side to a matching position, the effective diameter r of the disk 220 becomes large compared with the past, and ensuring of the required limiter torque Tlm becomes easy. In addition, a space is conventionally formed in the inner peripheral portion of the coil end 76, and the space is effectively used by arranging the torque limiter device 202 in this space, and the axial length of the power transmission device 200 is increased. Is shortened.

The disc spring 207 presses the rotor core 78 in the axial direction toward the first stopper portion 216 side. Therefore, the member for holding the rotor core 78 in the axial direction can be eliminated on the friction engagement element 205 side of the rotor core 78. Further, since the electromagnetic steel plate is pressed by the disc spring 207, it is possible to prevent the lubricating oil from seeping out between the laminated electromagnetic steel plates, thereby preventing a reduction in efficiency of the electric motor M1.

As described above, according to the present embodiment, the friction engagement element 2058 of the torque limiter device 202 can be disposed on the outer peripheral side to the position adjacent to the rotor 74 (rotor core 78) of the electric motor M1, so that the disk 220 It is possible to secure a large effective diameter r. Accordingly, the necessary limiter torque Tlm can be obtained without increasing the number of disks 220 or increasing the thickness of the disk 220. Further, since the friction engagement element 205 is disposed on the inner peripheral side of the coil end 76, the space formed on the inner peripheral side of the coil end 76 is effectively utilized, and the axial length of the power transmission device 200 is increased. It can be shortened.

The end plate 206 is provided on the outer peripheral side of the friction engagement element 205, and a disc spring 207 that presses the friction engagement element 205 is preloaded between the friction engagement element 205 and the rotor 74 in the axial direction. It is inserted in the state. In this way, since the electromagnetic steel plate constituting the rotor 74 is pressed in the axial direction by the disc spring 207, the member for fixing the electromagnetic steel plate can be eliminated, and the power transmission device 200 is simplified.

Further, since the disc spring 207 presses the electromagnetic steel plates constituting the rotor core 78 in the axial direction, it is possible to prevent the lubricating oil from seeping out between the laminated electromagnetic steel plates.

Further, since the lubricating oil is discharged in the outer circumferential direction by the centrifugal force from the communication hole 201b formed in the rotor shaft 201, the friction engagement element 205 and the coil end 76 are effectively lubricated.

As mentioned above, although the Example of this invention was described in detail based on drawing, this invention is applied also in another aspect.

For example, in the above-described embodiment, the

torque limiter devices

24 and 202 are provided in the power transmission path between the first electric motor M1 and the drive wheels 40. However, the power between the second electric motor M2 and the drive wheels 40 is not limited. It may be provided in the transmission path. Even in such a case, since the torque transmitted to the second electric motor M2 is limited, it is possible to reduce the size of the bearing that supports the second electric motor M2 and the diameter of the rotor shaft.

In the above-described embodiment, the outer peripheral portion of the disc spring 207 is spline-fitted to the inner peripheral teeth formed on the cylindrical portion 214. However, the spline fitting is not necessarily required. For example, a configuration in which the outer peripheral end of the disc spring 207 is disposed on the inner peripheral side of the inner peripheral tooth of the cylindrical portion 214, or a space in which the disc spring 207 can be disposed is formed by blocking the inner peripheral tooth of the cylindrical portion 214 in the middle. It may be configured as described above.

It should be noted that the above is only one embodiment, and the present invention can be carried out in a mode in which various changes and improvements are added based on the knowledge of those skilled in the art.

12: Case 24, 202: Torque limiter device 40: Drive wheel 70, 204: Power transmission shaft (power transmission member)
74: Rotor 76: Coil end 82: First end plate (end plate)
98, 205: Friction engagement elements 100, 207: Belleville spring 206: End plate M1: First electric motor (electric motor)

Claims

A torque limiter device for a vehicle provided in a power transmission path between an electric motor and drive wheels,
The torque limiter device includes an end plate that rotates integrally with the rotor of the electric motor, a power transmission member, and a friction engagement element that connects the end plate and the power transmission member so as not to be connected or disconnected.
The friction engagement element is disposed on the inner peripheral side of the coil end of the electric motor,
A torque limiter device for a vehicle, wherein a rotor of the electric motor is supported by a case via the power transmission member.
The end plate is provided on the inner peripheral side with respect to the friction engagement element,
2. The vehicle torque according to claim 1, wherein a disc spring for pressing the friction engagement element is interposed between the friction engagement element and the power transmission member in a preload state in an axial direction. Limiter device.
The end plate is provided on the outer peripheral side of the friction engagement element,
2. The vehicle torque limiter device according to claim 1, wherein a disc spring for pressing the friction engagement element is interposed between the friction engagement element and the rotor in a preload state in an axial direction. .