Power transmission device of hybrid vehicle

Abstract

To provide a power transmission device of a hybrid vehicle which enables reduction of a dimension of a clutch in a rotation center axis direction and can achieve downsizing.SOLUTION: A power transmission device 4 includes: a case 10 which houses a wet clutch 25; a damper 21 which is disposed between an internal combustion engine 1 and the wet clutch 25 and absorbs rotational fluctuation of the internal combustion engine 1; and a release mechanism 36 which operates the wet clutch 25 so as to connect / disconnect the internal combustion engine 1 to / from a transmission 3. The release mechanism 36, the wet clutch 25, and the damper 21 are disposed within the case 10 in an order of the release mechanism 36, the wet clutch 25, and the damper 21 from the transmission 3 side in a rotation center axis direction. The wet clutch 25 is rotatably supported through a bearing 11E by a left case part 10B. The damper 21 is rotatably supported through a bearing 11F by the wet clutch 25.SELECTED DRAWING: Figure 5

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. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-165348 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the drive device described in Patent Document 1 is provided with a main clutch, a first clutch, and a second clutch that can connect or disconnect power between the internal combustion engine and the transmission and between the motor and the transmission, but there is no description of a specific configuration for compactly arranging these clutches, which increases the number of clutch parts and may result in the drive device becoming larger.

[0006] Furthermore, when a damper is provided between the internal combustion engine and the transmission to absorb fluctuations in rotation of the internal combustion engine, the number of parts in the drive device increases further, which may result in the drive device becoming even larger.

[0007] 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 be made smaller by shortening the dimension in the direction of the central axis of rotation of the clutch. [Means for solving the problem]

[0008] 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 is equipped with a case that houses the clutch, a damper that is arranged between the internal combustion engine and the clutch and absorbs rotational fluctuations of the internal combustion engine, and a clutch operating member that operates the clutch to connect and disconnect power between the internal combustion engine and the transmission, and the clutch operating member, the clutch, and the damper are arranged inside the case in the direction of the central axis of rotation of the clutch in the order of clutch operating member, clutch, and damper from the transmission side, and the clutch is rotatably supported on the case via a first bearing, and the damper is rotatably supported on the clutch via a second bearing. [Effects of the Invention]

[0009] As described above, according to the present invention, the dimension of the clutch in the direction of the central axis of rotation can be shortened, thereby making it possible to reduce the size of the power transmission device. [Brief explanation of the drawings]

[0010] [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] FIG. 5 is a cross-sectional view of a power transmission device according to one embodiment of the present invention, taken along the line VV in FIG. [Figure 6] FIG. 6 is a cross-sectional view of a power transmission device according to one embodiment of the present invention, showing a transmission path of a release reaction force (corresponding to a cross-sectional view taken along the arrows VV in FIG. 3). DETAILED DESCRIPTION OF THE INVENTION

[0011] 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 is provided with a case that houses the clutch, a damper that is arranged between the internal combustion engine and the clutch and absorbs rotational fluctuations of the internal combustion engine, and a clutch operating member that operates the clutch to connect and disconnect power between the internal combustion engine and the transmission, and the clutch operating member, clutch, and damper are arranged inside the case in the direction of the central axis of rotation of the clutch in the order of clutch operating member, clutch, and damper from the transmission side, and the clutch is rotatably supported on the case via a first bearing, and the damper is rotatably supported on the clutch via a second bearing.

[0012] As a result, the power transmission device for a hybrid vehicle according to one embodiment of the present invention can reduce the dimension of the clutch in the direction of the central axis of rotation, thereby making it possible to reduce the size of the power transmission device. [Example]

[0013] 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.

[0014] 1 to 6 are diagrams showing a power transmission device for a hybrid vehicle according to one embodiment of the present invention.

[0015] First, the configuration will be described. In Figures 1 to 6, the up, down, front, rear, left and right directions are based on the power transmission device when installed in a vehicle, and the front and rear directions of the hybrid vehicle are defined as the front-to-rear direction, the left and right directions of the hybrid vehicle (vehicle width direction) are defined as the left and right direction, and the up and down directions of the hybrid vehicle (hybrid vehicle height direction) are defined as the up and down direction.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 1, the power transmission device 4 has a thin, flat shape in the axial direction (the direction in which C1, which will be described later, extends) and includes a case 10 that forms an outer shell. The case 10 is divided in the left-right direction, and has a right case portion 10A (see FIG. 3) located on the internal combustion engine 1 side and a left case portion 10B (see FIG. 4) located on the transmission 3 side.

[0028] Bosses 10a and 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 and 10b are fastened together with bolts 9A, thereby integrating the right case portion 10A and the left case portion 10B.

[0029] The case 10 is disposed between the internal combustion engine 1 and the transmission 3 and is coupled 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] A damper 21 is housed in the case 10. The damper 21 has a damper input member 22, a damper output member 23, and a coil spring 24. The damper 21 is disposed at the same position as the bearing support portion 10c in the axial direction (the direction in which C1, which will be described later, extends).

[0034] That is, the bearing support portion 10c is disposed radially outside the damper 21. Interference between the damper 21 and the bearing support portion 10c in the radial direction is avoided, and the axial length (thickness) of the power transmission device 4 can be shortened.

[0035] The damper 21 is a disk-shaped component that is thin in the axial direction, and is arranged along the right case portion 10A on the internal combustion engine 1 side inside the case 10. 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.

[0036] Specifically, the crankshaft 1B has a plurality of threaded holes 1a formed around the rotational axis thereof, the threaded holes 1a extending in the direction of the rotational axis (left-right direction) of the crankshaft 1B.

[0037] The shaft mounting portion 22A has a plurality of through holes 22a through which the bolts 9B pass, formed to match the positions of the screw holes 1a, and the through holes 22a face the screw holes 1a in the direction of the central axis of rotation of the damper 21.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] The coil spring 24 is disposed circumferentially between the spring holding portion 22D and the outer end of the damper output member 23, and transmits the driving force between the damper input member 22 and the damper output member 23. Its elastic deformation allows relative rotational displacement between the damper input member 22 and the damper output member 23, absorbing minute fluctuations in the driving force.

[0042] 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.

[0043] When rotational fluctuations (torque fluctuations) occur in the internal combustion engine 1, the coil spring 24 elastically deforms in the circumferential direction to absorb the fluctuations, and the damper input member 22 and the damper output member 23 rotate relative to each other, so that the rotational fluctuations of the internal combustion engine 1 are absorbed without being transmitted from the damper input member 22 to the damper output member 23.

[0044] 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 to allow relative displacement between the damper input member 22 and the damper output member 23 in the circumferential direction, and transmits torque while absorbing vibrations.

[0045] 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 .

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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. In more detail, the right end of the driven gear 29 is connected to the outer periphery of the outer disc portion 27A, and extends cylindrically from the outer disc portion 27A toward the transmission 3.

[0051] 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.

[0052] 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 damper 21 have approximately the same outer diameter. The driven gear 29 and the coil spring 24 are disposed side by side in the direction of the central rotation axis.

[0053] 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.

[0054] 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.

[0055] The outer cylindrical portion 27B extends cylindrically 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 cylindrically from the outer disc portion 27A toward the internal combustion engine 1.

[0056] 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.

[0057] 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.

[0058] The inner disc portion 27C extends inward from the right end (end on the internal combustion engine 1 side) of the outer cylindrical portion 27B so as to be continuous with the outer disc portion 27A, and the inner end of the inner disc portion 27C is connected to the right end (end on the internal combustion engine 1 side) of the inner cylindrical portion 27D.

[0059] 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.

[0060] The transmission 3 is provided with a flywheel 3C and a gear-changing clutch 3A. The shaft 3a of the flywheel 3C is inserted into the inner cylindrical portion 27F and is spline-fitted to the inner periphery of the inner cylindrical portion 27D. This allows the clutch output member 27 to rotate integrally with the flywheel 3C.

[0061] 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 is supported by the bearing 11G so as to be rotatable relative to the flywheel 3C.

[0062] 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.

[0063] 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.

[0064] When the input side friction plate 30 and the output side friction plate 31 come into contact with each other and generate friction force, 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 so that power can be transmitted.

[0065] 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.

[0066] 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.

[0067] As shown in FIG. 5, the biasing member 28 has an annular pressure plate 32, a disc spring 33, and an annular retainer 34.

[0068] The outer end of the pressing plate 32 faces the output-side friction plate 31, which is located on the internal combustion engine 1 side in the direction of the central axis of rotation, and the biasing force of the disc spring 33 presses the output-side friction plate 31 against the input-side friction plate 30. The disc spring 33 biases the pressing 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.

[0069] That is, the biasing member 28 is a member that maintains the clutch input member 26 and the clutch output member 27 connected via the input side friction plates 30 and the output side friction plates 31, and biases the input side friction plates 30 and the output side friction plates 31 to press them against the clutch output member 27 so as to sandwich the input side friction plates 30 and the output side friction plates 31 together with the clutch output member 27. The wet clutch 25 of this embodiment is a normally closed type.

[0070] The retainer 34 is attached to a cylindrical bearing support portion 27b. The bearing support portion 27b 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. The bearing support portion 27b fits inside the friction plate holding portion 27a.

[0071] The retainer 34 is attached to the bearing support portion 27b so as to be immovable in the direction of the rotation axis, 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. The disc spring 33 is disposed between the bearing support portion 27b and the friction plate holding portion 27a.

[0072] 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.

[0073] The bearing retaining flange 13 has a disc portion 13A that abuts the inner wall surface of the left case portion 10B, and a cylindrical portion 13C that is connected to the disc portion 13A via a connecting portion 13B and extends from the inner end of the connecting portion 13B toward the clutch output member 27 side (the internal combustion engine 1 side), and the connecting portion 13B is fixed to the left case portion 10B by a bolt 9C.

[0074] The outer ring 11a of the bearing 11E is sandwiched between the retainer 34 and the left case portion 10B in the axial direction, and the bearing 11E is fixed to the left case portion 10B. The cylindrical portion 13C is disposed inside the driven gear 29, and the bearing 11E is also disposed inside the driven gear 29, which allows the axial length of the power transmission device 4 to be shortened.

[0075] Case 10 houses release mechanism 36, and 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. Release mechanism 36 is arranged so as to fit inside driven gear 29.

[0076] The release mechanism 36 has a cam plate 37, balls 38, a thrust plate 39, a release bearing 40, and an operating member 41. The release mechanism 36 of this embodiment constitutes a clutch operating member.

[0077] The cam plate 37, ball 38, and thrust plate 39 are arranged in the same radial position as the input side friction plate 30 and the output side friction plate 31, and are arranged in the order of thrust plate 39, ball 38, and cam plate 37 from the clutch output member 27 side.

[0078] The cam plate 37 is rotated within a certain range around the central axis of rotation by a clutch actuator (not shown).

[0079] A plurality of cam grooves 37a are formed on the surface of the cam plate 37 facing the thrust plate 39, and the cam grooves 37a are arranged at regular intervals in the circumferential direction of the cam plate 37.

[0080] Each cam groove 37a extends in the circumferential direction of the cam plate 37 (the rotational direction of the internal combustion engine 1), and has an inclined surface whose depth in the direction of the rotational axis becomes shallower from one end to the other end in the rotational direction of the internal combustion engine 1. In other words, the depth of the cam groove 37a in the direction of the rotational axis changes from one side to the other side in the circumferential direction.

[0081] The thrust plate 39 is formed with a cam groove 39a, and the ball 38 is accommodated in the cam groove 39a.

[0082] The cam groove 39a is formed in a semicircular shape so that the balls 38 only roll without moving in the circumferential direction.

[0083] The thrust plate 39 is rotationally engaged with a pin 39b fixed to the bearing holding flange 13, so that the thrust plate 39 is non-rotatable but movable in the direction of the central axis of rotation.

[0084] 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.

[0085] 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.

[0086] A head 41a having a diameter larger than the diameter of the through hole 27c is formed at the end of the operating member 41 on the internal combustion engine 1 side, 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 side.

[0087] In other words, the large-diameter head 41a is positioned between the pressure plate 32, which receives the biasing force of the disc spring 33, and the outer disk portion 27A, so that the operating member 41 can be attached with a simple configuration while preventing it from falling off, and the device can be made more compact.

[0088] The outer ring of the release bearing 40 is fixed to the thrust plate 39 and moves integrally with the thrust plate 39 in the direction of the rotational axis.

[0089] The inner ring of the release bearing 40 is in contact with the operating member 41, and the outer ring and inner ring 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 release bearing 40 abuts against the wet clutch 25 in the direction of the central axis of rotation.

[0090] When the clutch actuator rotates the cam plate 37 from one side to the other (clutch disengagement direction), the cam groove 37a moves relative to the ball 38, and the ball 38 moves from a position on the deep inclined surface to a position on the shallow inclined surface, increasing the amount by which the ball 38 protrudes from the cam plate 37.

[0091] As a result, the balls 38 are pushed out toward the clutch output member 27 , and the pushed-out balls 38 press the thrust plate 39 toward the clutch output member 27 .

[0092] When the thrust plate 39 is pressed toward the clutch output member 27, the release bearing 40 presses the operating member 41 toward the clutch output member 27, causing the pressure plate 32 to move toward the internal combustion engine 1 against the biasing force of the disc spring 33, and the force from the pressure plate 32 no longer acts on the input side friction plate 30 and the output side friction plate 31.

[0093] 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 interrupted.

[0094] On the other hand, in the release mechanism 36, when the clutch actuator rotates the cam plate 37 from one side to the other (clutch connection direction), the cam groove 37a moves relative to the ball 38, and the ball 38 moves from the shallow inclined surface position to the deep inclined surface position, thereby reducing the amount by which the ball 38 protrudes from the cam plate 37.

[0095] At this time, the thrust plate 39, release bearing 40 and balls 38 are pressed toward the transmission 3 by the biasing force of the disc spring 33, and the pressure plate 32 moves from the internal combustion engine 1 side toward the transmission 3 side.

[0096] 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 are sandwiched between the pressure plate 32 and the clutch output member 27 (outer disc portion 27A), generating a strong friction force. 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.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] In hybrid driving, the internal combustion engine 1 can be operated in a fuel-efficient state, and the driving force of the motor generator 2 can improve the acceleration performance of the hybrid vehicle.

[0105] Furthermore, 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.

[0106] 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.

[0107] As a result, engine braking does not occur when the hybrid vehicle decelerates, so energy loss due to engine braking is reduced and power during deceleration from the transmission 3 is transmitted to the motor generator 2, allowing for efficient power regeneration.

[0108] 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.

[0109] 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 inward from the outer periphery of the driven gear 29. In other words, the release mechanism 36 is disposed so as to be recessed inside the driven gear 29, thereby making the device more compact.

[0110] 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.

[0111] 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.

[0112] A step 27f is formed at the left 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.

[0113] A bent portion 13a is formed at the end of the right end of the cylindrical portion 13C by bending the right end of the cylindrical portion 13C radially inward, and the right end of the outer ring 11a of the bearing 11E abuts against the bent portion 13a.

[0114] The left end of bearing 11E abuts against a step 10f (see FIG. 6) formed on the inner end of left case portion 10B.

[0115] The inner ring 11b of the bearing 11E is sandwiched between the snap ring 42 and the bent portion 13a in the axial direction and is immovable in the axial direction. The outer ring 11a of the bearing 11E is in contact with the bent portion 13a and the step portion 10f and is immovable in the axial direction.

[0116] 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.

[0117] 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.

[0118] 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.

[0119] 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.

[0120] 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 made up of the space between the outer cylindrical portion 27B and the inner cylindrical portion 27D of the clutch output member 27 and the space inside the shaft attachment portion 22A.

[0121] 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.

[0122] 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.

[0123] Specifically, the working 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 attachment work to be performed by accommodating tools and bolts 9B (not shown).

[0124] 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, 11D, 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.

[0125] 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.

[0126] 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.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] 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.

[0132] First, the unitized power transmission device 4 is prepared before being attached to the crankshaft 1B.

[0133] 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.

[0134] 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).

[0135] 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.

[0136] 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 .

[0137] 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.

[0138] 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.

[0139] Next, the effects of the power transmission device 4 for the hybrid vehicle of this embodiment will be described. The power transmission device 4 of this embodiment includes a case 10 that houses the wet clutch 25, a damper 21 that is arranged between the internal combustion engine 1 and the wet clutch 25 and absorbs rotational fluctuations of the internal combustion engine 1, and a release mechanism 36 that operates the wet clutch 25 to connect and disconnect power between the internal combustion engine 1 and the transmission 3.

[0140] The release mechanism 36, wet clutch 25, and damper 21 are arranged inside the case 10 in the order of release mechanism 36, wet clutch 25, and damper 21 from the transmission 3 side in the direction of the central axis of rotation.

[0141] The wet clutch 25 is rotatably supported by the left case portion 10B via a bearing 11E, and the damper 21 is rotatably supported by the wet clutch 25 via a bearing 11F.

[0142] This makes it possible to shorten the axial length of power transmission device 4. Specifically, since power transmission device 4 is arranged with release mechanism 36, wet clutch 25, and damper 21 arranged in this order from transmission 3 in the direction of the central axis of rotation, it is conceivable that release mechanism 36, wet clutch 25, and damper 21 could each be rotatably supported on case 10 via bearings.

[0143] In this case, it is necessary to arrange the three bearings in line in the direction of the central axis of rotation, and to arrange the release mechanism 6, wet clutch 25, and damper 21, which may increase the axial length of the power transmission device 4.

[0144] In the power transmission device 4 of this embodiment, the damper 21 is rotatably supported on the wet clutch 25 via the bearing 11F, thereby eliminating the need for a bearing on the internal combustion engine 1 side to support the damper 21 on the right case portion 10A, and the release mechanism 36, the wet clutch 25, and the damper 21 can be rotatably supported by the two bearings 11E and 11F.

[0145] Therefore, the axial length of the power transmission device 4 can be shortened, thereby enabling the miniaturization of the power transmission device 4. As a result, by disposing the power transmission device 4 with a short axial length between the internal combustion engine 1 and the transmission 3, the overall length of the internal combustion engine 1 and the transmission 3 including the power transmission device 4 can be shortened, enabling the miniaturization of the hybrid vehicle.

[0146] Furthermore, according to the power transmission device 4 of this embodiment, the bearing 11E has an outer ring 11a attached to the left case portion 10B and an inner ring 11b attached to the wet clutch 25 and rotatably connected to the outer ring 11a via balls 11c, and the outer ring 11a and the inner ring 11b are fixed to the left case portion 10B and the wet clutch 25, respectively, so as to be unable to move in the direction of the central axis of rotation.

[0147] This allows the release reaction force to be received by bearing 11E, and the release reaction force acting on case 10 can be reduced.

[0148] Specifically, when the release mechanism 36 presses the disc spring 33 to disengage the wet clutch 25, a release reaction force, which is a reaction load of the release load, is generated.

[0149] As shown in FIG. 6, this release reaction force F is transmitted to the bearing retaining flange 13 (left case portion 10B) via the cam plate 37, ball 38, thrust plate 39, release bearing 40, operating member 41, pressure plate 32, disc spring 33, clutch output member 27, and bearing 11E.

[0150] In other words, when the release mechanism 36 disengages the wet clutch 25, it pushes the pressure plate 32 in a direction away from the left case portion 10B, but the bearing 11E attached to the left case portion 10B and the clutch output member 27 tries to maintain the positional relationship between the left case portion 10B and the clutch output member 27, so the release reaction force F is received by the bearing 11E, and the release reaction force F acting on the right case portion 10A can be reduced.

[0151] This makes it unnecessary to increase the overall thickness of the case 10 or to add a rib shape to increase the overall rigidity of the case 10.

[0152] Therefore, it is possible to prevent the thickness of the case 10 in the direction of the central axis of rotation from increasing, and it is possible to shorten the dimension of the power transmission device 4 in the direction of the central axis of rotation.

[0153] The power transmission device 4 of this embodiment also has a drive gear 2B to which the power of the motor generator 2 is input, and a driven gear 29 that is provided on the outer diameter portion of the wet clutch 25 and meshes with the drive gear 2B.

[0154] The driven gear 29 is formed to have a larger diameter than the cam plate 37 of the release mechanism 36, and the driven gear 29 and the release mechanism 36 are disposed at the same position in the direction of the central axis of rotation.

[0155] This allows the axial length of the power transmission device 4 to be even shorter than when the driven gear 29 and the release mechanism 36 are arranged side by side in the direction of the central axis of rotation, thereby making it possible to further reduce the size of the power transmission device 4.

[0156] 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]

[0157] 1. Internal combustion engine 2 Motor generator (rotating electric machine) 2B Drive gear 3-speed 4 Power transmission device 10 cases 11a outer ring 11b Inner circle 11c Ball (rolling element) 11E Bearing (first bearing) 11F bearing (second bearing) 21 Damper 25 Wet clutch (clutch) 29 Driven gear 36 Release mechanism (clutch operating member) 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 case that houses the clutch; a damper disposed between the internal combustion engine and the clutch, the damper absorbing rotation fluctuations of the internal combustion engine; a clutch operating member that operates the clutch to connect and disconnect power between the internal combustion engine and the transmission, the clutch operating member, the clutch, and the damper are arranged inside the case in this order from the transmission side in a direction of a central axis of rotation of the clutch, the clutch is rotatably supported on the case via a first bearing, 10. A power transmission device for a hybrid vehicle, wherein the damper is rotatably supported by the clutch via a second bearing.

2. the first bearing has an outer ring attached to the case, and an inner ring attached to the clutch and rotatably connected to the outer ring via a rolling portion, 2. The power transmission device for a hybrid vehicle according to claim 1, wherein the outer ring and the inner ring are fixed to the case and the clutch, respectively, so as to be immovable in the direction of the rotational axis of the front clutch.

3. a drive gear to which power of the rotating electric machine is input; a driven gear provided at an outer end of the clutch and meshing with the drive gear, The driven gear is formed to have a larger diameter than the clutch operating member, 3. The power transmission device for a hybrid vehicle according to claim 1, wherein the driven gear and the clutch operating member are arranged at the same position in the direction of the central axis of rotation of the clutch.

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