Power transmission device of hybrid vehicle

Abstract

To provide a power transmission device of a hybrid vehicle which enables a clutch to be switched from a disengaged state to an engaged state even if a clutch actuator is broken in a state where the clutch is disengaged.SOLUTION: A power transmission device 4 has: a release mechanism 36 which rotates around a rotation center axis C1 to move in a rotation axis direction and engage or disengage a wet clutch 25; and a clutch actuator which causes the release mechanism 36 to rotate around the rotation center axis C1. The release mechanism 36 is positioned in a clutch disengagement position where the release mechanism is rotated in a direction opposite to a rotation direction of an internal combustion engine 1 by the clutch actuator to disengage the wet clutch 25. In a state where the release mechanism is positioned in the clutch disengagement position, the release mechanism receives rotational force acting in a direction such that the wet clutch 25 is engaged from a clutch output member 27 of the wet clutch 25.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a power transmission device for a hybrid vehicle. [Background technology]

[0002] BACKGROUND ART A drive device for a hybrid vehicle is known that transmits power from either an internal combustion engine or a motor to drive wheels via a transmission (see Patent Document 1).

[0003] This drive device is provided between the internal combustion engine and the transmission and includes a main clutch that connects or disconnects the internal combustion engine and the transmission, a first clutch that can transmit or disconnect the power of the motor to a first power transmission part, and a second clutch that can transmit or disconnect the power of the motor to a second power transmission part.

[0004] On the other hand, a release clutch device equipped with a ball cam mechanism is known as a device for connecting and disconnecting a clutch (see Patent Document 2).

[0005] This release clutch device is provided with a pair of ball cam mechanisms that move the release bearing unit in the axial direction of the hollow shaft in response to the driving of the electric motor. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-165348 [Patent Document 2] Patent No. 6720690 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the release clutch device described in Patent Document 2, if the electric motor fails and the pair of ball cam mechanisms becomes inoperable, there is a risk that the release bearing unit will not be able to switch the clutch device from a disconnected state to a connected state, and there is still room for improvement.

[0008] The present invention has been made in light of the above-mentioned circumstances, and aims to provide a power transmission device for a hybrid vehicle that can switch the clutch from a disengaged state to an engaged state even if the clutch actuator fails while the clutch is disengaged. [Means for solving the problem]

[0009] The present invention is a power transmission device for a hybrid vehicle that is arranged between an internal combustion engine and a transmission, transmits power from a rotating electric machine to the transmission, and has a clutch that can connect and disconnect power between the internal combustion engine and the transmission, and that has: a release member that moves in the direction of the rotational axis of the clutch by rotating around the rotational axis of the clutch as the center of rotation, thereby connecting and disconnecting the clutch; and a clutch actuator that rotates the release member around the rotational axis of the clutch as the center of rotation, and is characterized in that the release member is rotated by the clutch actuator in the opposite direction to the rotational direction of the internal combustion engine to be positioned at a clutch disconnection position where the clutch is disconnected, and when positioned at the clutch disconnection position, it receives a rotational force from the clutch in a direction to connect the clutch. [Effects of the Invention]

[0010] As described above, according to the present invention, even if the clutch actuator fails while the clutch is disengaged, the clutch can be switched from the disengaged state to the engaged state. [Brief explanation of the drawings]

[0011] [Figure 1]FIG. 1 is a cross-sectional view of an internal combustion engine and a transmission equipped with a power transmission device according to one embodiment of the present invention (the power transmission device corresponds to a cross section taken along the VV direction in FIG. 3). [Figure 2] FIG. 2 is a schematic diagram of a hybrid vehicle equipped with a power transmission device according to one embodiment of the present invention. [Figure 3] FIG. 3 is a right side view (viewed from the internal combustion engine side) of a power transmission device according to an embodiment of the present invention. [Figure 4] FIG. 4 is a left side view (viewed from the transmission side) of a power transmission device according to one embodiment of the present invention. [Figure 5] 5 is a cross-sectional view taken along the arrows VV in FIG. [Figure 6] FIG. 6 is a view of the power transmission device according to one embodiment of the present invention, viewed from the transmission side, with the left case portion of the power transmission device removed. [Figure 7] FIG. 7 is a view of the cam plate of the power transmission device according to one embodiment of the present invention as viewed from the transmission side. [Figure 8] Figure 8 is a development of the cam groove of a cam plate of a power transmission device according to one embodiment of the present invention, where Figure 8(a) is a development of a cam groove used for comparison with the cam groove of this embodiment, and Figure 8(b) is a development of the cam groove of this embodiment. [Figure 9] Figure 9 is a cross-sectional view taken along the arrow IX-IX in Figure 7, where Figure 9(a) shows the positional relationship between the cam groove and the ball when the cam plate is positioned at the clutch engagement position, Figure 9(b) shows the positional relationship between the cam groove and the ball when the cam plate is positioned between the clutch engagement position and the clutch disengagement position, and Figure 9(c) shows the positional relationship between the cam groove and the ball when the cam plate is positioned at the clutch disengagement position. DETAILED DESCRIPTION OF THE INVENTION

[0012] A power transmission device for a hybrid vehicle according to one embodiment of the present invention is a power transmission device for a hybrid vehicle that is arranged between an internal combustion engine and a transmission, transmits power from a rotating electric machine to the transmission, and has a clutch that can connect and disconnect power between the internal combustion engine and the transmission, and has a release member that moves in the direction of the rotational axis of the clutch by rotating around the rotational axis of the clutch, thereby connecting and disconnecting the clutch, and a clutch actuator that rotates the release member around the rotational axis of the clutch, and the release member is rotated by the clutch actuator in the opposite direction to the rotational direction of the internal combustion engine, to be positioned at a clutch disconnection position where the clutch is disconnected, and when positioned at the clutch disconnection position, the release member receives a rotational force from the clutch in the direction of connecting the clutch.

[0013] As a result, the power transmission device of a hybrid vehicle according to one embodiment of the present invention can switch the clutch from a disengaged state to an engaged state even if the clutch actuator fails while the clutch is disengaged. [Example]

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A power transmission device for a hybrid vehicle according to an embodiment of the present invention will now be described with reference to the drawings.

[0015] 1 to 9 are diagrams showing a power transmission device for a hybrid vehicle according to one embodiment of the present invention.

[0016] First, the configuration will be described. In Figures 1 to 7, the up, down, front, back, left and right directions are based on the power transmission device when installed in a vehicle, and the front and back direction of the hybrid vehicle is the front-to-rear direction, the left and right direction of the hybrid vehicle (vehicle width direction) is the left and right direction, and the up and down direction of the hybrid vehicle (hybrid vehicle height direction) is the up and down direction.

[0017] As shown in Fig. 1, a hybrid vehicle has an internal combustion engine 1, a motor generator 2 (see Fig. 2) as a rotating electric machine, and a transmission 3. A power transmission device 4 is disposed between the internal combustion engine 1 and the transmission 3.

[0018] The internal combustion engine 1 includes an engine body 1A, and a crankshaft 1B extending in the vehicle width direction (left-right direction) is rotatably housed in the engine body 1A.

[0019] The internal combustion engine 1 burns fuel to convert thermal energy into mechanical energy, thereby rotating the crankshaft 1B about its central axis of rotation, and transmitting power to the transmission 3 via the power transmission device 4.

[0020] As shown in Fig. 2, the motor generator 2 transmits power to the transmission 3 via the power transmission device 4, and also has a regenerative function of generating electricity using the power transmitted from the transmission 3 via the power transmission device 4. The motor generator 2 is disposed on the internal combustion engine 1 side with respect to the power transmission device 4.

[0021] Specifically, the motor generator 2 functions as an electric motor that generates power using electricity supplied from a battery (not shown) via an inverter (not shown), and as a generator that generates power regeneratively using the rotational force (reverse power) input from the drive wheels 6L and 6R.

[0022] Under the control of an ECU (not shown), the inverter converts DC power supplied from the battery into three-phase AC power and supplies it to the motor generator 2, and also converts the three-phase AC power generated by the motor generator 2 into DC power to charge the battery. The battery is formed of a secondary battery such as a lithium-ion battery.

[0023] The inverter and the battery of this embodiment may be provided integrally with the motor generator 2, or may be mounted on the engine body 1A of the internal combustion engine 1 as a unit.

[0024] The transmission 3 includes a gear-changing clutch 3A and a gear change mechanism 3B. The gear-changing clutch 3A mechanically connects and disconnects the power transmitted from at least one of the internal combustion engine 1 and the motor generator 2.

[0025] Although not shown in detail, the transmission mechanism 3B is equipped with a plurality of transmission gears and synchronizers, etc., and changes the speed of the power (rotation) transmitted from at least one of the internal combustion engine 1 and the motor generator 2 according to the gear stage, and transmits it to the left and right drive wheels 6L, 6R via the left and right drive shafts 5L, 5R from a differential device not shown.

[0026] Furthermore, the gear change clutch 3A is mechanically disengaged when the gear is changed and is mechanically engaged when the gear is established. In other words, when the gear change clutch 3A is engaged, it connects the power transmission device 4 and the transmission 3 to transmit power, and when it is disengaged, it disconnects the power transmission device 4 and the transmission 3 to interrupt the transmission of power.

[0027] As shown in FIG. 1, the power transmission device 4 is disposed between the internal combustion engine 1 and the transmission 3, and transmits power from the motor generator 2 to the transmission 3, and has a wet clutch 25 (described later) that can connect and disconnect power between the internal combustion engine 1 and the transmission 3.

[0028] As shown in Figure 1, the power transmission device 4 has a case 10 that forms an outer shell, and the case 10 has a right case portion 10A (see Figure 3) located on the internal combustion engine 1 side and a left case portion 10B (see Figure 4) located on the transmission 3 side.

[0029] Bosses 10a, 10b are provided on the outer end of the right case portion 10A and the outer end of the left case portion 10B, and the bosses 10a, 10b are fastened together with bolts 9A. This integrates the right case portion 10A and the left case portion 10B. The case 10 is disposed between the internal combustion engine 1 and the transmission 3, and is connected to the internal combustion engine 1 and the transmission 3.

[0030] As shown in Figures 1 and 5, the right case portion 10A and the left case portion 10B are provided with annular bearing support portions 10c and 10d, respectively, and the drive shaft 2A of the motor generator 2 is rotatably supported by the bearing support portions 10c and 10d via bearings 11A and 11B.

[0031] An opening 10e is formed in the right case portion 10A, and the right end of the drive shaft 2A is disposed so as to protrude from the opening 10e to the outside of the case 10. An oil seal 12A is provided between the opening 10e and the drive shaft 2A, and the gap between the opening 10e and the drive shaft 2A is closed by the oil seal 12A.

[0032] A drive gear 2B is housed inside the case 10 and is located between the bearing supports 10c and 10d. The drive gear 2B is spline-fitted to the outer periphery of the drive shaft 2A and rotates integrally with the drive shaft 2A.

[0033] The case 10 accommodates a damper 21. The damper 21 has a damper input member 22, a damper output member 23, and a coil spring 24.

[0034] A shaft mounting portion 22A is provided at the inner end of the damper input member 22, and the shaft mounting portion 22A is fastened to the crankshaft 1B by a bolt 9B.

[0035] Specifically, the crankshaft 1B is formed with a plurality of threaded holes 1a extending in the direction of the central axis of rotation (left and right direction) of the crankshaft 1B.

[0036] A plurality of through holes 22a are formed in the shaft attachment portion 22A, through which the bolts 9B are passed. The through holes 22a face the threaded holes 1a in the direction of the central axis of rotation of the damper 21.

[0037] The shaft mounting portion 22A is mounted to the crankshaft 1B by inserting a bolt 9B into the through hole 22a and threading the bolt 9B into the threaded hole 1a. This allows the damper input member 22 to rotate integrally with the crankshaft 1B.

[0038] As shown in FIG. 5, the damper input member 22 has an inner circular plate portion 22B extending linearly radially outward from the shaft mounting portion 22A, an outer circular plate portion 22C connected to the inner circular plate portion 22B via a pin 7 and extending radially outward from the inner circular plate portion 22B, and a spring holding portion 22D provided at the outer end of the outer circular plate portion 22C and holding the coil spring 24 in the circumferential direction together with the damper output member 23.

[0039] The shaft attachment portion 22A, the inner disc portion 22B, the outer disc portion 22C and the spring holding portion 22D rotate integrally with the crankshaft 1B.

[0040] The coil spring 24 is disposed between the spring holding portion 22D and the outer end of the damper output member 23 in the circumferential direction, and connects the damper input member 22 and the damper output member 23 in the circumferential direction.

[0041] When the damper input member 22 rotates due to the rotation of the crankshaft 1B, the damper input member 22 transmits power to the damper output member 23 via the coil spring 24. As a result, the damper output member 23 and the damper input member 22 rotate integrally.

[0042] When rotational fluctuations (torque fluctuations) occur in the internal combustion engine 1, the coil spring 24 elastically deforms in the circumferential direction, causing the damper input member 22 and the damper output member 23 to rotate relative to each other via the coil spring 24, thereby absorbing the rotational fluctuations of the internal combustion engine 1.

[0043] In other words, the coil spring 24 elastically deforms in the circumferential direction of the damper input member 22 and the damper output member 23 so as to absorb the relative displacement between the damper input member 22 and the damper output member 23 in the circumferential direction.

[0044] The case 10 accommodates a wet clutch 25. The wet clutch 25 has a clutch input member 26, a clutch output member 27, and a biasing member .

[0045] The wet clutch 25 is disposed on the transmission 3 side with respect to the damper 21. That is, the damper 21 is disposed between the wet clutch 25 and the internal combustion engine 1. The wet clutch 25 of this embodiment constitutes a clutch.

[0046] The clutch input member 26 is formed integrally with the damper output member 23, and extends cylindrically from the outer end of the damper output member 23 toward the transmission 3.

[0047] Here, the central rotation axis of the crankshaft 1B, the central rotation axis of the flywheel 3C, the central rotation axis of the damper 21, and the central rotation axis of the wet clutch 25 are the same central rotation axis C1, and the crankshaft 1B, the flywheel 3C, the damper 21, and the wet clutch 25 are arranged so that the central rotation axis C1 is horizontal. Hereinafter, the direction of the central rotation axis C1 of each of these members will be referred to as the central rotation axis direction.

[0048] A speed reduction driven gear 29 having a diameter larger than that of the drive gear 2B is integrally provided on the outer periphery of the clutch output member 27, and the driven gear 29 rotates integrally with the clutch output member 27.

[0049] Specifically, the clutch output member 27 has an outer disc portion 27A. The driven gear 29 is provided integrally with the outer disc portion 27A on the outer periphery of the outer disc portion 27A, and rotates integrally with the outer disc portion 27A.

[0050] The driven gear 29 meshes with the drive gear 2B of the motor generator 2, and the power of the motor generator 2 is transmitted to the driven gear 29 via the drive gear 2B. In other words, the clutch output member 27 is connected to the motor generator 2 via the drive gear 2B and the driven gear 29, and is interlocked with the motor generator 2.

[0051] In this embodiment, the drive gear 2B is disposed so that its central rotation axis C2 is horizontal, and the central rotation axis C1 of the driven gear 29 and the central rotation axis C2 of the drive gear 2B are parallel to each other. The driven gear 29 and the coil spring 24 are disposed side by side in the direction of the central rotation axis.

[0052] A plurality of input side friction plates 30 are spline-fitted to the inner periphery of the clutch input member 26, and the input side friction plates 30 are rotatable integrally with the clutch input member 26 and are movable in the direction of the rotational center axis relative to the clutch input member 26.

[0053] The clutch output member 27 has an outer circular plate portion 27A, as well as an outer cylindrical portion 27B, an inner circular plate portion 27C, and an inner cylindrical portion 27D, and the outer circular plate portion 27A, the outer cylindrical portion 27B, the inner circular plate portion 27C, and the inner cylindrical portion 27D are integrally formed.

[0054] The outer cylindrical portion 27B extends from the inner end of the outer disc portion 27A toward the transmission 3. A cylindrical friction plate holding portion 27a is provided on the outer disc portion 27A between the driven gear 29 and the outer cylindrical portion 27B in the radial direction, and the friction plate holding portion 27a protrudes from the outer disc portion 27A toward the internal combustion engine 1.

[0055] A plurality of output-side friction plates 31 are provided on the outer periphery of the friction plate holding portion 27a. The output-side friction plates 31 are arranged between the input-side friction plates 30, and the output-side friction plates 31 and the input-side friction plates 30 are arranged so as to be alternately stacked in the axial direction.

[0056] The output side friction plate 31 is spline-fitted to the outer periphery of the friction plate holding portion 27a, and is rotatable integrally with the friction plate holding portion 27a and movable in the direction of the rotational axis relative to the friction plate holding portion 27a.

[0057] The inner disc portion 27C extends inward from the right end portion of the outer cylindrical portion 27B, and the inner end portion of the inner disc portion 27C is connected to the inner cylindrical portion 27D.

[0058] The inner cylindrical portion 27D extends from the inner end of the inner disc portion 27C toward the transmission 3, and is formed so that its length in the rotational axis direction is shorter than that of the outer cylindrical portion 27B.

[0059] The transmission 3 is provided with a flywheel 3C, and the outer periphery of the shaft 3a of the flywheel 3C is spline-fitted to the inner periphery of the inner cylindrical portion 27D, so that the clutch output member 27 rotates integrally with the flywheel 3C.

[0060] As shown in FIG. 1, an input shaft 3D of the transmission 3 is rotatably supported by the flywheel 3C via a bearing 11G, and the input shaft 3D rotates relative to the flywheel 3C via the bearing 11G.

[0061] The input shaft 3D and the flywheel 3C are connected via a gear-shift clutch 3A. When the gear-shift clutch 3A is engaged, power is transmitted between the input shaft 3D and the flywheel 3C. When the gear-shift clutch 3A is disengaged, power is cut off between the input shaft 3D and the flywheel 3C.

[0062] 5, a hole serving as bearing support portion 22b is provided at the axis of shaft attachment portion 22A of damper input member 22, and bearing 11C is disposed in bearing support portion 22b. Shaft portion 3a of flywheel 3C is rotatably supported by damper input member 22 via bearing 11C. In other words, shaft portion 3a of flywheel 3C and damper input member 22 rotate relative to each other via bearing 11C.

[0063] When the input side friction plate 30 and the output side friction plate 31 come into frictional contact with each other, the clutch input member 26 and the clutch output member 27 are connected via the input side friction plate 30 and the output side friction plate 31 .

[0064] As a result, the power of the internal combustion engine 1 is transmitted to the flywheel 3C via the damper input member 22, the coil spring 24, the damper output member 23, the clutch input member 26, the output side friction plate 31, the input side friction plate 30 and the clutch output member 27.

[0065] Furthermore, when the motor generator 2 is driven, the power of the motor generator 2 is transmitted via the drive shaft 2A, the drive gear 2B, the driven gear 29 and the clutch output member 27 to the flywheel 3C.

[0066] As shown in FIG. 5, the biasing member 28 has an annular pressure plate 32, a disc spring 33, and an annular retainer 34.

[0067] The outer end of the pressure plate 32 faces the output side friction plate 31 located on the internal combustion engine 1 side in the direction of the central axis of rotation, and the disc spring 33 urges the pressure plate 32 toward the transmission 3 so that the input side friction plate 30 and the output side friction plate 31 come into contact with each other.

[0068] That is, the biasing member 28 biases the clutch output member 27 toward the clutch input member 26 so as to maintain a connected state between the clutch input member 26 and the clutch output member 27 via the input side friction plate 30 and the output side friction plate 31. The wet clutch 25 of this embodiment is a normally closed type.

[0069] The retainer 34 is attached to a cylindrical bearing support portion 27b, which protrudes radially from the outer disk portion 27A toward the internal combustion engine 1 between the driven gear 29 and the outer cylindrical portion 27B.

[0070] The retainer 34 is attached to the bearing support portion 27b so as to be immovable in the direction of the central axis of rotation, and the inner end of the disc spring 33 abuts against the retainer 34. The outer end of the disc spring 33 urges the pressure plate 32 toward the transmission 3, bringing the input side friction plate 30 and the output side friction plate 31 into frictional contact.

[0071] A bearing holding flange 13 is fixed to the left case portion 10B by bolts 9C, and the bearing holding flange 13 forms a part of the left case portion 10B.

[0072] The bearing retaining flange 13 has a disk portion 13A that abuts the inner wall surface of the left case portion 10B, and a cylindrical portion 13C that is connected to the disk portion 13A via a connecting portion 13B and extends from the inner end of the connecting portion 13B toward the internal combustion engine 1, and the connecting portion 13B is fixed to the left case portion 10B by a bolt 9C.

[0073] The case 10 houses a release mechanism 36, and the release mechanism 36, wet clutch 25 and damper 21 are arranged in this order from the transmission 3 side in the direction of the central axis of rotation.

[0074] The release mechanism 36 has a cam plate 37, a bearing holding flange 13, balls 38, a release bearing 40, an operating member 41, and a clutch actuator 51 (see FIG. 6). The release mechanism 36 of this embodiment constitutes a release member.

[0075] The cam plate 37 is formed in an annular shape and is rotated by the clutch actuator 51 within a certain range around the rotation center axis C1.

[0076] Specifically, as shown in FIG. 6, teeth 37A are formed on the outer end of cam plate 37, and teeth 37A protrude outward from the outer end of cam plate 37 beyond driven gear 29.

[0077] Tooth portion 37A extends a fixed length in the circumferential direction of cam plate 37 and meshes with drive gear 51A of clutch actuator 51. When power is transmitted from drive gear 51A of clutch actuator 51 to tooth portion 37A, cam plate 37 rotates within a fixed range (arrange of arrangement of tooth portion 37A extending in the circumferential direction) around rotation center axis C1.

[0078] The tooth portion 37A of this embodiment constitutes a power transmission portion to which power is transmitted from the clutch actuator 51.

[0079] Cam grooves 37a are formed on the surface of the cam plate 37 facing the transmission 3. As shown in Fig. 7, the cam grooves 37a are spaced apart at regular intervals in the circumferential direction of the cam plate 37, and each extends in the circumferential direction of the cam plate 37 (the rotational direction of the internal combustion engine 1).

[0080] In this embodiment, three cam grooves 37a are arranged in the circumferential direction of the cam plate 37. However, the number of cam grooves 37a is not limited to three.

[0081] As shown in FIGS. 7 and 9, the cam groove 37a has a cam surface 37d whose depth in the rotational axis direction becomes shallower from an upstream end 37b to a downstream end 37c in the rotational direction R1 of the internal combustion engine 1.

[0082] Here, cam surface 37d is an inclined surface. That is, the depth of cam groove 37a in the direction of the central axis of rotation changes from upstream end 37b to downstream end 37c in the direction of rotation of internal combustion engine 1. Cam groove 37a shown in Figure 9 is a diagram that illustrates cam groove 37a in an easy-to-understand manner, and it goes without saying that the inclination rate of actual cam surface 37d is smaller than the inclination rate of cam surface 37d shown in Figure 9.

[0083] The inclination rate of downstream end 37c of cam surface 37d is smaller than the inclination rate of cam surface 37d excluding downstream end 37c. As shown in Figure 9, cam surface 37d at downstream end 37c is inclined in the opposite direction to the inclination direction of cam surface 37d excluding cam surface 37d at downstream end 37c.

[0084] In other words, the cam surface 37d at the downstream end 37c and the cam surface 37d excluding the cam surface 37d at the downstream end 37c are inclined in opposite directions across the change point 37e, which is located at the highest position on the cam surface 37d.

[0085] A ball holding portion 13b is formed on the disk portion 13A of the bearing holding flange 13, and the ball holding portion 13b holds the ball 38 so that the ball 38 can roll freely. This prevents the ball 38 from moving in the circumferential direction of the cam plate 37 relative to the disk portion 13A.

[0086] In order to allow the cam plate 37 to move easily and rotate smoothly, it is necessary to reduce resistance to the movement (forces that hinder movement, such as friction) as much as possible.

[0087] In this embodiment, ball 38 is held in ball holding portion 13b so that it can roll freely, but if the resistance of ball holding portion 13b becomes a problem, it is preferable to provide a cam groove in disk portion 13A as in cam plate 37, so that ball 38 can roll between cam groove 37a of cam plate 37 and the cam groove in disk portion 13A.

[0088] In this case, the inclination rate of the cam groove (cam surface) of the disk portion 13A should be the same as and parallel to the inclination rate of the cam surface 37d of the cam groove 37a of the cam plate 37. In addition, since the position of the ball 38 is not fixed, it is preferable to restrict the position of the ball 38 at the upstream end 37b or the downstream end 37c.

[0089] The cam plate 37 rotates relative to the bearing holding flange 13 because the connecting portion 13B is fixed to the left case portion 10B by the bolt 9C and is therefore unable to rotate.

[0090] 5, a through hole 27c is formed in the outer disk portion 27A of the clutch output member 27. An operating member 41 is inserted into the through hole 27c, and is guided by the through hole 27c to be movable in the direction of the central axis of rotation.

[0091] The biasing force of the disc spring 33 acts on the operating member 41 via the pressure plate 32, and the operating member 41 is pressed towards the transmission 3 by the disc spring 33.

[0092] A head 41a having a diameter larger than the diameter of the through hole 27c is formed at the right end of the operating member 41, and the head 41a abuts against the outer disc portion 27A around the through hole 27c, thereby restricting movement of the operating member 41 toward the transmission 3.

[0093] The outer ring of the release bearing 40 is fixed to the cam plate 37 and moves integrally with the cam plate 37 in the direction of the rotational axis.

[0094] The inner ring of the release bearing 40 is in contact with the operating member 41, and the outer and inner rings rotate relative to each other, thereby moving the operating member 41 in the direction of the central axis of rotation while allowing the operating member 41 to rotate. In other words, the inner ring of the release bearing 40 abuts against the operating member 41, which rotates integrally with the clutch output member 27 in the direction of the central axis of rotation, and rotates integrally with the clutch output member 27.

[0095] In the release mechanism 36, when the cam plate 37 is rotated from one side to the other (clutch disengagement direction) by the clutch actuator 51, the cam groove 37a moves relative to the ball 38, and the contact position with the ball 38 moves from the position of the deep cam surface 37d to the position of the shallow cam surface 37d, increasing the amount by which the ball 38 protrudes from the cam plate 37.

[0096] As a result, the cam plate 37 moves toward the clutch output member 27 (the internal combustion engine 1), and the release bearing 40 attached to the cam plate 37 moving toward the internal combustion engine 1 also moves toward the internal combustion engine 1. Then, the release bearing 40 presses the operating member 41 toward the internal combustion engine 1.

[0097] At this time, the pressure plate 32 moves toward the internal combustion engine 1 against the biasing force of the disc spring 33, and the clamping force of the pressure plate 32 on the input side friction plate 30 and the output side friction plate 31 is released.

[0098] As a result, a gap is created between the input side friction plate 30 and the output side friction plate 31, the wet clutch 25 is disengaged, and the power transmitted from the internal combustion engine 1 to the transmission 3 is cut off.

[0099] On the other hand, when the cam plate 37 is rotated from the other side to one side (clutch connection direction) by the clutch actuator 51, the cam groove 37a moves relative to the ball 38, and the contact position with the ball 38 moves from the position of the shallow cam surface 37d to the position of the deep cam surface 37d, thereby reducing the amount by which the ball 38 protrudes from the cam plate 37.

[0100] At this time, the cam plate 37 is pressed toward the transmission 3 by the biasing force of the disc spring 33, and the pressing plate 32 moves from the internal combustion engine 1 side toward the transmission 3 side by the biasing force of the disc spring 33.

[0101] As a result, the pressure plate 32 presses the output-side friction plate 31 toward the transmission 3, and the input-side friction plate 30 and the output-side friction plate 31 come into frictional contact. As a result, the wet clutch 25 is engaged, and the power of the internal combustion engine 1 is transmitted to the transmission 3 via the wet clutch 25.

[0102] Furthermore, when the wet clutch 25 is in an engaged state, the damper output member 23 is connected to the flywheel 3C (i.e., the transmission 3) via the clutch input member 26, the input side friction plate 30, the output side friction plate 31, and the clutch output member 27. Therefore, when rotational fluctuations (torque fluctuations) occur in the internal combustion engine 1, the coil spring 24 elastically deforms in the circumferential direction, causing the damper input member 22 and the damper output member 23 to rotate relative to each other via the coil spring 24, thereby absorbing the rotational fluctuations in the internal combustion engine 1.

[0103] As shown in FIG. 7, the cam plate 37 is rotated in the rotation direction R2 by the clutch actuator 51 and is positioned at a clutch disengagement position where the wet clutch 25 is disengaged.

[0104] In other words, when the cam plate 37 rotates from the clutch engagement position in a rotation direction R2 opposite to the rotation direction R1 of the internal combustion engine 1, the ball 38 moves from the upstream end 37b, which is deep in the direction of the rotation axis of the cam groove 37a, along the cam surface 37d to the clutch disengagement position at the downstream end 37c, which is shallow in the direction of the rotation axis, thereby disengaging the wet clutch 25.

[0105] On the other hand, when the cam plate 37 rotates from the clutch disengagement position in the same direction as the rotational direction R1 of the internal combustion engine 1, the ball 38 moves from the downstream end 37c, which is shallow in the direction of the rotational axis of the cam groove 37a, to the clutch engagement position at the upstream end 37b, which is deep in the direction of the rotational axis, thereby engaging the wet clutch 25.

[0106] In the power transmission device 4 of this embodiment, during engine running in which the hybrid vehicle is driven by the power of the internal combustion engine 1, the gear change clutch 3A of the transmission 3 and the wet clutch 25 are in an engaged state.

[0107] As a result, the power of the internal combustion engine 1 is transmitted to the flywheel 3C via the damper input member 22, coil spring 24, damper output member 23, clutch input member 26, input side friction plate 30, output side friction plate 31 and clutch output member 27, and then transmitted from the flywheel 3C to the input shaft 3D via the speed-changing clutch 3A.

[0108] During motor running, in which the internal combustion engine 1 is stopped and the hybrid vehicle is driven by the power of the motor generator 2, the gear change clutch 3A of the transmission 3 is connected and the wet clutch 25 is disconnected.

[0109] As a result, the power of the motor generator 2 is transmitted to the flywheel 3C via the drive shaft 2A, drive gear 2B, driven gear 29 and clutch output member 27, and then transmitted from the flywheel 3C to the input shaft 3D via the speed-changing clutch 3A.

[0110] During hybrid running, in which the hybrid vehicle is driven by the power of the internal combustion engine 1 and the motor generator 2, the gear change clutch 3A of the transmission 3 and the wet clutch 25 are brought into an engaged state.

[0111] As a result, power is transmitted from the internal combustion engine 1 and the motor generator 2 to the transmission 3 via a power transmission path similar to the power transmission path from the internal combustion engine 1 to the transmission 3 and the power transmission path from the motor generator 2 to the transmission 3 described above.

[0112] In hybrid running, the internal combustion engine 1 can be operated in a fuel-efficient state, and the acceleration performance of the hybrid vehicle can be improved.

[0113] When the hybrid vehicle is decelerating (regenerating), the gear change clutch 3A of the transmission 3 is connected and the wet clutch 25 is disconnected, thereby completely disconnecting the internal combustion engine 1 from the drive wheels 6L, 6R.

[0114] As a result, the power of the drive wheels 6L, 6R is transmitted to the transmission 3 via the drive shafts 5L, 5R and the differential device, and then transmitted from the input shaft 3D of the transmission 3 to the motor generator 2 via the flywheel 3C, clutch output member 27, driven gear 29, drive gear 2B and drive shaft 2A, thereby causing the motor generator 2 to regenerate power.

[0115] Since engine braking does not occur when the hybrid vehicle is decelerating, the energy loss due to engine braking is reduced and the power transmitted from the transmission 3 to the motor generator 2 can be efficiently regenerated.

[0116] In this embodiment, driven gear 29 is formed to have a larger diameter than release mechanism 36. Specifically, of the members constituting release mechanism 36, cam plate 37 is the member with the largest diameter, and driven gear 29 is formed to have a larger diameter than cam plate 37.

[0117] The driven gear 29 and the release mechanism 36 are disposed at the same position in the direction of the central axis of rotation, and the release mechanism 36 is disposed so as to be inserted inside the driven gear 29 .

[0118] A bearing 11E is provided between the outer periphery of the outer cylindrical portion 27B of the clutch output member 27 and the inner periphery of the cylindrical portion 13C of the bearing holding flange 13, and the clutch output member 27 is rotatably supported on the bearing holding flange 13 (i.e., the left case portion 10B) via the bearing 11E.

[0119] A snap ring 42 is fitted onto the outer periphery of the outer cylindrical portion 27B, and the left end of the inner ring 11b of the bearing 11E abuts against the snap ring 42.

[0120] A step 27f is formed at the right end of the outer cylindrical portion 27B, and the right end of the inner ring 11b of the bearing 11E abuts against the step 27f.

[0121] The right end of cylindrical portion 13C is bent radially inward to form bent portion 13a, and the right end of outer ring 11a of bearing 11E abuts against bent portion 13a. The left end of outer ring 11a of bearing 11E abuts against a step formed on the inner end of left case portion 10B.

[0122] As a result of the above, inner ring 11b of bearing 11E is sandwiched between snap ring 42 and bent portion 13a in the direction of the central axis of rotation and is unable to move in the direction of the central axis of rotation. Also, outer ring 11a of bearing 11E abuts bent portion 13a and a step portion at the inner end of left case portion 10B and is unable to move in the direction of the central axis of rotation.

[0123] As a result, the clutch output member 27 is rotatably supported by the left case portion 10B but is immovable in the direction of the rotational axis.

[0124] That is, bearing 11E has an outer ring 11a attached to left case portion 10B and an inner ring 11b attached to wet clutch 25 and rotatably connected to outer ring 11a via balls 11c, and outer ring 11a and inner ring 11b are fixed to left case portion 10B and wet clutch 25, respectively, so as to be unable to move in the direction of the central axis of rotation.

[0125] A bearing 11F is provided between the outer periphery of shaft mounting portion 22A of damper input member 22 and bearing support portion 27b, and damper input member 22 is rotatably supported by clutch output member 27 via bearing 11F.

[0126] Bearing 11F is a sealed type bearing, and is designed so that lubricating oil cannot pass through the inside of bearing 11F. O-rings, which are sealing members, are disposed between the outer ring and inner ring of bearing 11F and shaft mounting portion 22A and bearing support portion 27b, respectively, and are attached so that lubricating oil inside case 10 does not leak.

[0127] 5, a working space 43 opens at the inner end side of the clutch output member 27. The working space 43 opens on the transmission 3 side, and is formed by the space between the outer cylindrical portion 27B and the inner cylindrical portion 27D of the clutch output member 27.

[0128] A plurality of through holes 27d are formed in inner disk portion 27C of clutch output member 27 (see FIG. 4), and through holes 27d face through hole 22a of damper input member 22 and screw hole 1a in the direction of the central rotation axis.

[0129] The work space 43 is made up of a space where the power transmission device 4 can be assembled to the internal combustion engine 1 and the transmission 3.

[0130] Specifically, the work space 43 is formed to have a size that allows the damper input member 22 to be attached to the crankshaft 1B with the bolts 9B, and that allows the damper input member 22 to be attached to the crankshaft 1B with the bolts 9B to be attached thereto.

[0131] Meanwhile, the case 10 has an accommodation space 45 that accommodates the drive gear 2B, the damper 21, the wet clutch 25, the biasing member 28, the driven gear 29, and the release mechanism 36. The accommodation space 45 contains lubricating oil that cools the input side friction plate 30 and the output side friction plate 31 of the wet clutch 25 and lubricates the bearings 11A, 11B, 11E, 11F, etc. Figures 3 and 4 show the height (oil level) of the lubricating oil O. The oil level of the lubricating oil O is located below the central axis of rotation.

[0132] The case 10 houses an oil guide (not shown), which supplies lubricating oil scooped up by the driven gear 29 to the meshing portion between the drive gear 2B and the driven gear 29.

[0133] As shown in FIG. 5, an annular oil seal 12B is provided between an outer circumferential portion 22d of a shaft mounting portion 22A of the damper input member 22 and the inner end portion of the right case portion 10A.

[0134] An oil seal 12C is provided between the outer periphery of the outer cylindrical portion 27B of the clutch output member 27 and the inner end of the left case portion 10B.

[0135] That is, the oil seals 12B and 12C are positioned radially outward from the multiple threaded holes 1a of the crankshaft 1B and the multiple through holes 22a of the shaft mounting portion 22A, and the storage space 45 in which the lubricating oil is sealed is liquid-tightly sealed from the working space 43 by the oil seals 12B and 12C and the bearing 11F.

[0136] The through hole 22a is disposed inside a work space 43 where the power transmission device 4 is attached to the crankshaft 1B, and the oil seals 12B and 12C are disposed radially outward from the work space 43.

[0137] Next, a method for assembling the power transmission device 4 of the hybrid vehicle to the internal combustion engine 1 and the transmission 3 will be described.

[0138] The power transmission device 4 is unitized with a portion of the drive shaft 2A, the drive gear 2B, the damper 21, the wet clutch 25, the biasing member 28, the driven gear 29, and the release mechanism 36 housed in a housing space 45, and lubricating oil is sealed in the housing space 45.

[0139] First, the unitized power transmission device 4 is prepared before being attached to the crankshaft 1B.

[0140] To mount the unitized power transmission device 4 on the internal combustion engine 1, the power transmission device 4 is positioned relative to the internal combustion engine 1 so that the threaded hole 1a of the crankshaft 1B and the through hole 22a of the shaft mounting portion 22A are aligned.

[0141] Next, the bolt 9B is fitted into the threaded hole 1a through the through hole 22a, and then a tool is inserted into the working space 43, and the bolt 9B is screwed into the threaded hole 1a using the tool. This operation is repeated the number of times equal to the number of threaded holes 1a (six in this embodiment).

[0142] As a result, the damper input member 22 is fastened to the crankshaft 1B by the bolt 9B, and the power transmission device 4 is attached to the internal combustion engine 1.

[0143] Next, the shaft portion 3 a of the flywheel 3 C is spline-fitted to the inner cylindrical portion 27 D of the clutch output member 27 , and the power transmission device 4 is assembled to the transmission 3 .

[0144] In this manner, the power transmission device 4 is assembled to the internal combustion engine 1 and the transmission 3. The motor generator 2 may be attached to the power transmission device 4 before the power transmission device 4 is attached to the internal combustion engine 1, or may be attached to the power transmission device 4 after the power transmission device 4 is attached to the internal combustion engine 1 and the transmission 3.

[0145] Therefore, a hybrid vehicle can be constructed by attaching the power transmission device 4 together with the motor generator 2 to an existing internal combustion engine 1 and transmission 3 without changing the specifications of the internal combustion engine 1 and transmission 3 for a hybrid vehicle.

[0146] Next, the effects of the power transmission device 4 for the hybrid vehicle of this embodiment will be described. FIG. 8(a) shows a cam groove 37a in which the inclination rate of the cam surface 37d is constant as a comparative example of the cam groove 37a of this embodiment, and FIG. 8(b) is a development view of the cam groove 37a of this embodiment.

[0147] 8(a) and 8(b), the vertical axis represents the depth of the cam groove, and the horizontal axis represents the twist angle between the cam plate 37 and the bearing retaining flange 13. In FIG.

[0148] 8 schematically shows the forces generated at the contact point between cam surface 37d and ball 38, with F1 representing the force that ball 38 receives from cam surface 37d. F corresponds to the release load (the load that presses against disc spring 33), and T1 and T2 correspond to the holding torque of cam plate 37. Note that F1 represents the resultant force of release load F and holding torque T1, and F2 represents the resultant force of release load F and holding torque T2.

[0149] The wet clutch 25 of this embodiment is a normally closed clutch, so when the clutch actuator 51 is not driven, the input side friction plate 30 and the output side friction plate 31 are in frictional contact with each other due to the biasing force of the disc spring 33, resulting in a connected state.

[0150] Therefore, in order to put the wet clutch 25 into a disengaged state, the clutch actuator 51 is energized to drive the clutch actuator 51, and power is transmitted from the drive gear 51A of the clutch actuator 51 to the tooth portion 37A, causing the cam plate 37 to rotate in the rotation direction R2 with the rotation center axis C1 as the rotation center.

[0151] At this time, the cam plate 37 moves from a state in which the ball 38 is positioned on the deep cam surface 37d at the upstream end 37b of the cam groove 37a (see Figure 9(a)) to a state in which the ball 38 is positioned on the shallow cam surface 37d at the downstream end 37c (see Figure 9(c)).

[0152] As a result, the cam plate 37 moves toward the internal combustion engine 1 in the direction of the central axis of rotation, and the release bearing 40 presses the operating member 41 toward the internal combustion engine 1 against the biasing force of the disc spring 33, releasing the clamping force between the input side friction plate 30 and the output side friction plate 31. As a result, the wet clutch 25 is disengaged.

[0153] Since the operating member 41 is pressed toward the internal combustion engine 1 against the biasing force F of the disc spring 33, in order to maintain the wet clutch 25 in the disengaged state, as shown in Figure 8(a), it is necessary to apply a holding torque T1 from the clutch actuator 51 to the cam plate 37 to maintain the contact position with the ball 38 on the cam surface 37d at the upstream end 37b.

[0154] Here, when disengaging the wet clutch 25, the clutch actuator 51 rotates the cam plate 37 against the biasing force of the disc spring 33 to press the release bearing 40 toward the internal combustion engine 1. However, since the operation of switching the wet clutch 25 from the disengaged state to the engaged state depends on the biasing force of the disc spring 33, if the operation of switching the wet clutch 25 from the disengaged state to the engaged state is to be prioritized, the biasing force of the disc spring 33 must be increased.

[0155] If the biasing force of the disc spring 33 is increased, the holding torque T1 must be increased in order to switch the wet clutch 25 from the connected state to the disconnected state and maintain the disconnected state, which increases the power consumption of the clutch actuator 51.

[0156] Conversely, if the biasing force of disc spring 33 is reduced in an attempt to reduce the power consumption of clutch actuator 51 by reducing holding torque T1, it becomes difficult to switch wet clutch 25 from the disengaged state to the engaged state in the event of a malfunction of clutch actuator 51. In other words, it becomes difficult for cam surface 37d of cam plate 37 to move relative to ball 38, and cam plate 37 will no longer rotate due to the biasing force of disc spring 33.

[0157] Specifically, the cam groove 37a of this embodiment has a cam surface 37d whose depth in the direction of the central axis of rotation becomes shallower from the upstream end 37b to the downstream end 37c. The inclination rate (inclination angle) of this cam surface 37d affects the holding torque T1.

[0158] Therefore, if the inclination rate of cam surface 37d is reduced, the holding torque T1 of cam plate 37 is reduced and the power consumption of clutch actuator 51 can be reduced; however, if clutch actuator 51 fails (no power is supplied) while cam plate 37 is rotated to the clutch disengagement position, there is a risk that cam plate 37 will not automatically rotate so that the position at which it abuts ball 38 changes from downstream end 37c (shallow cam surface 37d) to upstream end 37b (deep cam surface 37d) due to the biasing force of disc spring 33.

[0159] Conversely, if the inclination rate of cam surface 37d is increased, if clutch actuator 51 fails while cam plate 37 is rotated to the clutch disengagement position, cam plate 37 will be more likely to rotate due to the biasing force of disc spring 33, but the holding torque T1 of cam plate 37 at the clutch disengagement position will increase, and the power consumption of clutch actuator 51 will increase.

[0160] The power transmission device 4 of this embodiment has a release mechanism 36 that moves in the direction of the rotational axis by rotating around the rotational axis C1, thereby connecting and disconnecting the wet clutch 25, and a clutch actuator 51 that rotates the release mechanism 36 around the rotational axis C1.

[0161] The release mechanism 36 is rotated by the clutch actuator 51 in the opposite direction (rotation direction R2) to the rotation direction R1 of the internal combustion engine 1 to reach a clutch disengagement position where the wet clutch 25 is disengaged. Therefore, when positioned in the clutch disengagement position, the release mechanism 36 can receive a rotational force in the direction of connecting the wet clutch 25 not only from the spring force of the disc spring 33 but also from the clutch output member 27 of the wet clutch 25.

[0162] As a result, if the clutch actuator 51 fails while the cam plate 37 is in the clutch disengagement state, the rotational force of the clutch output member 27 can be applied to the release mechanism 36 to rotate the cam plate 37.

[0163] Furthermore, because the clutch output member 27 and cam plate 37 are connected via the release bearing 40, the rotational force transmitted from the clutch output member 27 to the cam plate 37 becomes the rotational resistance of the release bearing 40. In other words, the rotational resistance of the release bearing 40 can be added in the direction of engaging the wet clutch 25.

[0164] Therefore, the cam plate 37 can be rotated in the same direction as the rotation direction R1 of the internal combustion engine 1 (opposite to the rotation direction R2), and the cam plate 37 can be returned from the clutch disengagement position (see FIG. 9(c)) to the clutch engagement position (see FIG. 9(a)). As a result, the vehicle can be reliably driven by the internal combustion engine 1.

[0165] The power transmission device 4 of this embodiment also has a biasing member 28 that biases the wet clutch 25 to the engaged state.

[0166] The release mechanism 36 has a cam groove 37a whose depth in the direction of the rotational axis varies, and has a cam plate 37 that rotates between a clutch engagement position where the wet clutch 25 is in an engaged state and a clutch disengagement position.

[0167] Release mechanism 36 is provided so as to be movable along cam groove 37a, and has balls 38 that press cam plate 37 in the direction of the rotation axis against the biasing force of disc spring 33 when cam plate 37 rotates from the clutch disengagement position to the clutch engagement position, and release bearing 40 that is attached to cam plate 37 and abuts against operating member 41 that rotates integrally with clutch output member 27 in the direction of the rotation axis.

[0168] The cam groove 37a extends along the rotation direction of the cam plate 37 and has a cam surface 37d whose depth in the direction of the rotational axis becomes shallower from the upstream end 37b toward the downstream end 37c in the rotation direction R1 of the internal combustion engine 1, and the inclination rate of the cam surface 37d at the downstream end 37c may be smaller than the inclination rate of the cam surface 37d excluding the cam surface 37d at the downstream end 37c.

[0169] That is, as shown in FIG. 8(b), the inclination rate of the cam surface 37d may be changed at the change point 37e, and the inclination rate of the cam surface 37d may be made gentler in the range where the wet clutch 25 is disengaged.

[0170] This reduces the force required to maintain the disengaged state of the wet clutch 25, which does not use the power of the internal combustion engine 1 for traveling.

[0171] That is, with the ball 38 positioned at the clutch disengagement position at the upstream end 37b, the holding torque T1 of the cam plate 37 can be reduced, and the power consumption of the clutch actuator 51 can be reduced.

[0172] In addition, since the load applied from the cam plate 37 to the clutch actuator 51 can be reduced, a decrease in the durability of the clutch actuator 51 can be suppressed.

[0173] Furthermore, even if the holding torque T1 of the cam plate 37 is reduced when the cam plate 37 rotates to the clutch disengagement position, the rotational force of the clutch output member 27 can be applied to the cam plate 37, so that the cam plate 37 can be returned from the clutch disengagement position to the clutch engagement position beyond the change point 37e.

[0174] Furthermore, the inclination rate of cam surface 37d is changed at change point 37e, but as shown in Figure 8(b), it is also possible to set the inclination rate of cam surface 37d at change point 37e to 0 or to reverse the inclination direction of cam surface 37d.

[0175] According to the power transmission device 4 of this embodiment, the cam surface 37d at the downstream end 37c is inclined in the opposite direction to the inclination direction of the cam surfaces 37d other than the cam surface 37d at the downstream end 37c (see FIG. 8(b)).

[0176] This makes it possible to reduce the holding torque T1 of the cam plate 37 when the cam plate 37 is rotated to the clutch disengagement position, or to generate a holding torque T2 generated by the biasing force of the disc spring 33 in the opposite direction to the holding torque T1.

[0177] Therefore, when the cam plate 37 is rotated to the clutch disengagement position, the holding torque T1 required for the clutch actuator 51 can be further reduced, and the power consumption of the clutch actuator 51 can be further reduced.

[0178] Furthermore, even if the holding torque T1 of the cam plate 37 is reduced when the cam plate 37 rotates to the clutch disengagement position, the rotational force of the clutch output member 27 can be applied to the cam plate 37, so that the cam plate 37 can be returned from the clutch disengagement position to the clutch engagement position.

[0179] In other words, the cam groove 37a of this embodiment, which reverses the inclination direction shown in Figure 8(b), is formed as an inclined surface so that if the clutch actuator 51 fails and the ball 38 moves from the cam surface 37d at the upstream end 37b past the change point 37e, the biasing force of the disc spring 33 will apply a force in the direction of bringing the wet clutch 25 into the connected state.

[0180] Cam surface 37d at downstream end 37c may be a flat surface. Even if cam surface 37d at downstream end 37c is a flat surface, holding torque T1 can be further reduced when cam plate 37 is rotated to the clutch disengagement position, and power consumption of clutch actuator 51 can be further reduced.

[0181] In addition, the power transmission device 4 of this embodiment has a driven gear 29 that meshes with the drive gear 2B of the motor generator 2, and the cam plate 37 protrudes outward from the driven gear 29 and has a tooth portion 37A to which power is transmitted from the clutch actuator 51.

[0182] As a result, by providing the tooth portion 37A radially rather than axially relative to the cam plate 37, the length of the power transmission device 4 in the axial direction of rotation can be shortened, thereby making the power transmission device 4 more compact.

[0183] While an embodiment of the present invention has been disclosed, it will be apparent to one skilled in the art that modifications may be made thereto without departing from the scope of the present invention, and it is intended that all such modifications and equivalents be included in the following claims. [Explanation of symbols]

[0184] 1. Internal combustion engine 2 Motor generator (rotating electric machine) 2B Drive gear 3-speed 4 Power transmission device 25 Wet clutch (clutch) 36 Release mechanism (release member) 37 Cam plate 37A Teeth (power transmission part) 37a Cam groove 37d Cam surface 38 balls 40 Release bearing 51 Clutch actuator C1 Rotational axis (rotational axis of the clutch)

Claims

1. A power transmission device for a hybrid vehicle, comprising a clutch disposed between an internal combustion engine and a transmission, transmitting power from a rotating electric machine to the transmission, and capable of connecting and disconnecting power between the internal combustion engine and the transmission, a release member that moves in the direction of the central axis of rotation of the clutch by rotating about the central axis of rotation of the clutch, thereby connecting and disconnecting the clutch; a clutch actuator that rotates the release member around the rotation center axis of the clutch, The release member is the clutch actuator rotates the clutch in the direction opposite to the rotation direction of the internal combustion engine to a clutch disengagement position where the clutch is disengaged; 10. A power transmission device for a hybrid vehicle, wherein, when the power transmission device is in the clutch disengagement position, the power transmission device receives a rotational force from the clutch in a direction to engage the clutch.

2. The clutch has a biasing member that biases the clutch to an engaged state, The release member is a cam plate having a cam groove whose depth in the direction of the rotational axis of the clutch changes, and which rotates between a clutch engagement position where the clutch is in an engaged state and a clutch disengagement position; a ball that is provided movably along the cam groove and presses the cam plate in the direction of the rotational axis of the clutch against the biasing force of the biasing member when the cam plate rotates from the clutch engagement position to the clutch disengagement position; a release bearing attached to the cam plate and in contact with the clutch in a direction of the central axis of rotation of the clutch, the cam groove has a cam surface that extends along the rotation direction of the cam plate and has a depth in the direction of the rotation axis of the clutch that becomes shallower from the upstream end toward the downstream end in the rotation direction of the internal combustion engine, 2. The power transmission device for a hybrid vehicle according to claim 1, wherein the inclination rate of the cam surface at the downstream end in the rotational direction of the internal combustion engine is smaller than the inclination rate of the cam surface excluding the downstream end in the rotational direction of the internal combustion engine.

3. 3. The power transmission device for a hybrid vehicle according to claim 2, wherein the cam surface at the downstream end in the rotational direction of the internal combustion engine is flat or inclined in a direction opposite to the inclination direction of the cam surface excluding the cam surface at the downstream end in the rotational direction of the internal combustion engine.

4. a driven gear that meshes with a drive gear of the rotating electric machine, 4. The power transmission device for a hybrid vehicle according to claim 2, wherein the cam plate has a power transmission portion that protrudes outward beyond the driven gear and to which power is transmitted from the clutch actuator.

Images