Power transmission device of hybrid vehicle

Abstract

To provide a power transmission device of a hybrid vehicle which can be easily assembled to a space between an internal combustion engine / rotary electric machine and a transmission in a state where a lubrication oil is enclosed in a case while achieving downsizing and achieve improvement of workability of the assembly work.SOLUTION: In a power transmission device 4, a work space 43 in which a damper 21 and a crank shaft 1B of an internal combustion engine 1 are connected is open at the inner end side of a clutch output member 27. An oil seal 12B is disposed between an outer periphery part 22d of a shaft attachment part 22A of a damper input member 22 and a case 10, and an oil seal 12C is disposed between an outer periphery part 27c of an intermediate cylindrical part 27D of the clutch output member 27 and the case 10. A storage space 45 of the case 10 in which the damper 21 and a wet clutch 25 are housed is sealed from the work space 43 in a fluid-tight manner by the oil seal 12B and the oil seal 12C.SELECTED DRAWING: Figure 1

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, and in addition, the number of clutch parts increases, which could 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] Therefore, since the clutch and damper that connect and disconnect the motor's power are placed between the internal combustion engine and the transmission, the number of parts in the drive unit increases, making the work of assembling the drive unit between the internal combustion engine and motor and the transmission more tedious and potentially reducing the workability of assembling the drive unit.

[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 is compact, can be easily assembled between an internal combustion engine and a rotating electric machine and a transmission with lubricating oil sealed in the case, and can improve the workability of assembly work. [Means for solving the problem]

[0009] The present invention relates to a power transmission device for a hybrid vehicle, which is disposed between an internal combustion engine and a transmission, and which has a clutch that transmits power from a rotating electric machine to the transmission and is capable of connecting and disconnecting power between the internal combustion engine and the transmission, the power transmission device comprising: a case that houses the clutch; and a damper that is housed in the case and is disposed between the clutch and the internal combustion engine, and absorbs rotation fluctuations of the internal combustion engine, the damper including a damper input member that is connected at an inner end to the internal combustion engine and through which power of the internal combustion engine is transmitted; a damper output member that is capable of transmitting power of the internal combustion engine to the clutch; and an elastic member that is disposed between the damper input member and the damper output member in the circumferential direction, the clutch being provided integrally with the damper output member and having a first friction coefficient at its inner end. and a clutch output member having an outer end provided with a second friction plate that can be connected to and disconnected from the first friction plate and an inner end connected to the transmission so as to rotate integrally with the rotating shaft of the transmission, wherein a work space is open at the inner end side of the clutch output member where assembly work for assembling the damper to the internal combustion engine can be performed, a first oil seal is arranged between the damper input member and the case, and a second oil seal is arranged between the clutch output member and the case, and the storage space of the case that houses the damper and the clutch is liquid-tightly sealed from the work space by the first oil seal and the second oil seal. [Effects of the Invention]

[0010] Thus, according to the present invention, the power transmission device can be made smaller while easily being assembled between the internal combustion engine and rotating electric machine and the transmission with lubricating oil sealed in the case, thereby improving the workability of assembling the power transmission device. [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 line III-III in FIG. 4). [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 cross-sectional view of a power transmission device according to one embodiment of the present invention (a cross-sectional view taken along the arrows III-III in FIG. 4). [Figure 4] FIG. 4 is a right side view (viewed from the internal combustion engine side) of a power transmission device according to one embodiment of the present invention. [Figure 5] FIG. 5 is a left side view (viewed from the transmission side) of a power transmission device according to one embodiment of the present invention. [Figure 6] FIG. 6 is a cross-sectional view of a power transmission device according to one embodiment of the present invention, showing the state before it is attached to an internal combustion engine. [Figure 7] FIG. 7 is a cross-sectional view of a power transmission device according to one embodiment of the present invention, showing the state in which the power transmission device is attached to the crankshaft of an internal combustion engine. 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, and that transmits power from a rotating electric machine to the transmission, and that has a clutch that can connect and disconnect power between the internal combustion engine and the transmission, and that has a case that houses the clutch, and a damper that is housed in the case and arranged between the clutch and the internal combustion engine, and that absorbs rotation fluctuations of the internal combustion engine, the damper including a damper input member that has an inner end connected to the internal combustion engine and through which power of the internal combustion engine is transmitted, a damper output member that can transmit power of the internal combustion engine to the clutch, and an elastic member that is arranged between the damper input member and the damper output member in the circumferential direction, and the clutch is in contact with the damper output member The damper is configured to include a clutch input member provided on a body and having a first friction plate at its inner end, and a clutch output member having a second friction plate at its outer end that can be connected to and disconnected from the first friction plate, and an inner end that is connected to the transmission and rotates integrally with the rotating shaft of the transmission, and a work space is opened at the inner end side of the clutch output member where assembly work can be performed to assemble the damper to the internal combustion engine, a first oil seal is arranged between the damper input member and the case, and a second oil seal is arranged between the clutch output member and the case, and the storage space of the case that houses the damper and the clutch is liquid-tightly sealed from the work space by the first oil seal and the second oil seal.

[0013] As a result, the power transmission device of a hybrid vehicle according to one embodiment of the present invention can be easily assembled between the internal combustion engine and rotating electric machine and the transmission with lubricating oil sealed in the case, while also achieving a compact power transmission device, thereby improving the workability of assembling the power transmission device. [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 7 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 hybrid 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 is disposed on the internal combustion engine 1 side with respect to the power transmission device 4. 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.

[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 regenerative power using the rotational force (reverse driving force) 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 battery of this embodiment may be provided integrally with the motor generator 2, or may be unitized and attached to the engine body 1A of the internal combustion engine 1. The motor generator 2 of this embodiment constitutes a rotating electric machine.

[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] 1 and 3, 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 located on the internal combustion engine 1 side and a left case portion 10B 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] 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 (see Figure 4), 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, thereby causing the damper input member 22 to rotate integrally with the crankshaft 1B.

[0039] As shown in FIG. 3 , the damper input member 22 has an inner cylindrical portion 22B that extends radially outward in a straight line from the shaft mounting portion 22A and then extends in the direction of the central axis of rotation of the damper 21 toward the transmission 3, an outer cylindrical portion 22C that extends radially outward from the inner cylindrical portion 22B and then extends in the direction of the central axis of rotation of the damper 21 toward the internal combustion engine 1, and a spring holding portion 22D that extends radially outward from the outer cylindrical portion 22C and holds the coil spring 24 in the circumferential direction together with the damper output member 23.

[0040] The shaft attachment portion 22A, the inner cylindrical portion 22B, the outer cylindrical portion 22C and the spring holding portion 22D are integrally formed and rotate integrally with the crankshaft 1B.

[0041] An annular bearing support portion 10f is provided in the right case portion 10A, and the bearing support portion 10f is inserted between the inner cylindrical portion 22B and the outer cylindrical portion 22C. A bearing 11C is provided between the inner periphery of the outer cylindrical portion 22C and the bearing support portion 10f. As a result, the damper input member 22 is rotatably supported by the right case portion 10A via the bearing 11C.

[0042] That is, shaft attachment portion 22A, inner cylindrical portion 22B, bearing support portion 10f, bearing 11C, outer cylindrical portion 22C, and multiple coil springs 24 are concentrically arranged in this order in the radial direction.

[0043] The damper output member 23 is arranged so as to be inserted between the bearing 11C and the plurality of coil springs 24, and is arranged at a position where it overlaps with the damper input member 22 (more specifically, the outer cylindrical portion 22C) in the direction of the central axis of rotation of the damper 21. The damper output member 23 abuts against the damper input member 22 via the thrust bearing 11D and is connected to the damper input member 22 so as to be rotatable relative to it.

[0044] The coil spring 24 is disposed circumferentially between the outer end of the damper input member 22 and the outer end of the damper output member 23, transmits driving force between the damper input member 22 and the damper output member 23, and absorbs minute fluctuations in driving force by elastically deforming, allowing relative rotational displacement between the damper input member 22 and the damper output member 23. The coil spring 24 in this embodiment constitutes an elastic member.

[0045] 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.

[0046] 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.

[0047] 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 of the damper input member 22 and the damper output member 23 in the circumferential direction, and transmits torque while absorbing vibrations.

[0048] 1 and 3, a wet clutch 25 is housed in the case 10. The wet clutch 25 has a clutch input member 26, a clutch output member 27, and a biasing member .

[0049] 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 in the direction of the central axis of rotation of the wet clutch 25. The wet clutch 25 of this embodiment constitutes a clutch.

[0050] 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.

[0051] The clutch output member 27 is disposed so as to enter the inner diameter side of the clutch input member 26 , and is disposed at a position where it overlaps with the clutch input member 26 in the direction of the central axis of rotation of the wet clutch 25 .

[0052] Here, the rotational axis of the crankshaft 1B, the rotational axis of the flywheel 3C, the rotational axis of the damper 21, and the rotational axis of the wet clutch 25, including the rotational axis of the flywheel 3C described later, are all the same rotational axis C1, and the crankshaft 1B, the flywheel 3C, the damper 21, and the wet clutch 25 are arranged so that the rotational axis C1 is horizontal. Hereinafter, the direction in which the rotational axis C1 of each of these members extends will be referred to as the rotational axis direction.

[0053] 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.

[0054] 3, an outer disc portion 27A is provided at the outer end portion (the end portion on the transmission 3 side) of the clutch output member 27, and the driven gear 29 is fixed to the outer periphery of the outer disc portion 27A and rotates integrally with the outer disc portion 27A. The outer disc portion 27A is fixed to the end portion of the driven gear 29 on the transmission 3 side.

[0055] 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.

[0056] The drive gear 2B of this embodiment is disposed so that its rotational center axis C2 is horizontal, and the rotational center axis C1 of the driven gear 29 and the rotational center axis C2 of the drive gear 2B are parallel to each other.

[0057] The driven gear 29 and the damper 21 have approximately the same outer diameter. The driven gear 29 and the coil spring 24 are arranged side by side in the direction of the central axis of rotation. The clutch input member 26 and the driven gear 29 are not in contact with each other, and the clutch input member 26 rotates relative to the driven gear 29.

[0058] The clutch input member 26 is disposed between the driven gear 29 and the clutch output member 27 to achieve a compact size.

[0059] Arranged inside the cylindrical clutch input member 26 are an input side friction plate 30, an output side friction plate 31, and an outer disk portion 27A of the clutch output member 27, which will be described later.

[0060] 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.

[0061] The clutch output member 27 has, in addition to an outer disc portion 27A, an outer cylindrical portion 27B, an intermediate disc portion 27C, an intermediate cylindrical portion 27D, an inner disc portion 27E, and an inner cylindrical portion 27F, and the outer disc portion 27A, the outer cylindrical portion 27B, the intermediate disc portion 27C, the intermediate cylindrical portion 27D, the inner disc portion 27E, and the inner cylindrical portion 27F are integrally formed.

[0062] The cylindrical outer cylindrical portion 27B extends from the inner end of the outer disc portion 27A toward the internal combustion engine 1. A plurality of output-side friction plates 31 are spline-fitted to the outer periphery of the outer cylindrical portion 27B, and the output-side friction plates 31 are arranged between the input-side friction plates 30.

[0063] That is, the output-side friction plates 31 and the input-side friction plates 30 are arranged alternately. In this embodiment, the input-side friction plates 30 constitute first friction plates, and the output-side friction plates 31 constitute second friction plates.

[0064] The output side friction plate 31 is spline-fitted to the outer periphery of the outer cylindrical portion 27B, rotates integrally with the outer cylindrical portion 27B, and is movable in the direction of the rotation axis relative to the outer cylindrical portion 27B.

[0065] The input side friction plate 30 and the output side friction plate 31 are disposed radially inward of the driven gear 29 and overlap with the driven gear 29 at a position in the direction of the rotational axis.

[0066] The intermediate disc portion 27C of the clutch output member 27 extends inward from the right end (the end on the internal combustion engine 1 side) of the outer cylindrical portion 27B, and the inner end of the intermediate disc portion 27C is connected to the intermediate cylindrical portion 27D.

[0067] The intermediate cylindrical portion 27D is formed in a cylindrical shape and extends laterally along the axial direction from the connection portion with the inner end portion of the intermediate disc portion 27C. An inner disc portion 27E and an inner cylindrical portion 27F are arranged inside the intermediate cylindrical portion 27D.

[0068] The outer end of the inner disc portion 27E, which has a flat plate shape perpendicular to the axial direction, is connected to the inner periphery of the intermediate cylindrical portion 27D and is closer to the internal combustion engine 1 than the connection portion with the inner end of the intermediate cylindrical portion 27C. The inner disc portion 27E extends inward from the inner periphery of the intermediate cylindrical portion 27D, and the inner end of the inner disc portion 27E is connected to the outer periphery of the inner cylindrical portion 27F.

[0069] More specifically, the inner end of the inner disc portion 27E is connected to the end of the inner cylindrical portion 27F on the internal combustion engine 1 side. The length of the inner cylindrical portion 27F in the direction of the rotational axis is shorter than the length of the intermediate cylindrical portion 27D in the direction of the rotational axis, and the inner cylindrical portion 27F is disposed so as not to protrude from the intermediate cylindrical portion 27D. The inner peripheral portion of the cylindrical inner cylindrical portion 27F forms a spline hole.

[0070] 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 27F. This allows the clutch output member 27 to rotate integrally with the flywheel 3C.

[0071] 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.

[0072] The input shaft 3D and the flywheel 3C are connected via a speed-change clutch 3A, and when the speed-change clutch 3A is engaged, power is transmitted between the input shaft 3D and the flywheel 3C, and when the speed-change clutch 3A is disengaged, power is cut off between the input shaft 3D and the flywheel 3C. In this embodiment, the shaft portion 3a of the flywheel 3C forms the rotating shaft of the transmission.

[0073] 3, a hollow bearing support portion 22b is provided on shaft mounting portion 22A of damper input member 22, and shaft portion 3a of flywheel 3C is rotatably supported by bearing support portion 22b of damper input member 22 via bearing 11H. In other words, shaft portion 3a of flywheel 3C and damper input member 22 are supported by bearing 11H so as to be relatively rotatable.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] An annular bearing support portion 10g is provided in the left case portion 10B. The end portion of the intermediate cylindrical portion 27D on the transmission 3 side is disposed inside the bearing support portion 10g. A bearing 11E is provided between the bearing support portion 10g and the outer circumferential portion 27c of the intermediate cylindrical portion 27D of the clutch output member 27, and the clutch output member 27 is rotatably supported by the bearing support portion 10g via the bearing 11E.

[0078] A bearing 11F is provided between the inner peripheral portion of the inner cylindrical portion 22B of the damper input member 22 and the outer peripheral portion 27c of the intermediate cylindrical portion 27D, and the damper input member 22 is rotatably supported on the clutch output member 27 via the bearing 11F.

[0079] The urging member 28 has an annular pressure plate 32, a disc spring 33, and an annular disc spring holding plate 34. The annular pressure plate 32 is located on the internal combustion engine 1 side relative to the input side friction plate 30 and the output side friction plate 31, the disc spring 33 is located on the internal combustion engine 1 side relative to the pressure plate 32, and the annular disc spring holding plate 34 is arranged on the inner diameter side of the disc spring 33.

[0080] The outer end of the pressing 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 receives force from the disc spring 33 to press 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.

[0081] In other words, the biasing member 28 biases the input side friction plate 30 and the output side friction plate 31 toward the clutch output member 27 so as to maintain the clutch input member 26 and the clutch output member 27 connected via the input side friction plate 30 and the output side friction plate 31.

[0082] The wet clutch 25 of this embodiment is a normally closed type, and in normal operation when a release mechanism 36 (described later) is not operated, the input side friction plate 30 and the output side friction plate 31 are sandwiched between the biasing member 28 and the clutch output member 27.

[0083] The disc spring retaining plate 34 is connected to the clutch output member 27 by a rivet 35 and rotates integrally with the clutch output member 27 .

[0084] The disc spring 33 is an annular spring and is disposed in such a position that its outer end is located closer to the transmission 3 than its inner end in the axial direction.

[0085] The inner end of the disc spring 33 is held by a disc spring holding plate 34 so as not to move toward the internal combustion engine 1, and while held by the disc spring holding plate 34, the outer end of the disc spring 33 urges the pressure plate 32 toward the transmission 3, thereby clamping the input side friction plate 30 and the output side friction plate 31 between the clutch output member 27.

[0086] A washer 46 is provided between the disc spring holding plate 34 and the damper output member 23 in the direction of the central axis of rotation. The disc spring holding plate 34 receives force from the disc spring 33, and its movement toward the internal combustion engine 1 is restricted by the washer 46, thereby preventing direct contact with the damper output member 23.

[0087] The case 10 accommodates a release mechanism 36 that engages and disengages the wet clutch 25. The release mechanism 36 has a cam plate 37, balls 38, a thrust plate 39, a release bearing 40, and an operation plate 41.

[0088] Release mechanism 36 is disposed on the transmission 3 side of clutch output member 27, and is disposed so as to fit between outer cylindrical portion 27B and bearing 11E. In detail, cam plate 37, balls 38, and thrust plate 39 are disposed inside outer cylindrical portion 27B in this order from the transmission 3 side, and release bearing 40 is disposed on the inner diameter side thereof.

[0089] An operation plate 41 is disposed on the intermediate disc portion 27C side of the thrust plate 39 and the release bearing 40. The release mechanism 36 is disposed so as to be recessed inside the clutch output member 27, thereby achieving a compact size.

[0090] The cam plate 37 is rotated within a certain range around the central axis of rotation by a clutch actuator (not shown).

[0091] Cam grooves 37a are formed on the surface of the cam plate 37 facing the thrust plate 39, and a plurality of cam grooves 37a are arranged at regular intervals in the circumferential direction of the cam plate 37.

[0092] The cam groove 37a extends in the circumferential direction of the cam plate 37 (the rotational direction of the internal combustion engine 1), and is formed so that the depth in the direction of the central axis of rotation 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 central axis of rotation changes from one side to the other side in the circumferential direction.

[0093] A cam groove 39a is formed in the thrust plate 39, and a ball 38 is housed in the cam groove 39a. That is, the ball 38 is disposed between the cam groove 37a and the cam groove 39a.

[0094] The cam groove 39a is formed in a semicircular shape so that the balls 38 only roll without moving in the circumferential direction.

[0095] The thrust plate 39 is spline-fitted to a spline member 42 provided in the left case portion 10B, and is provided on the spline member 42 so as to be non-rotatable but movable in the direction of the rotational axis.

[0096] An opening 27a is formed in the intermediate disk portion 27C of the clutch output member 27 at the same radial position as the cam plate 37, the balls 38, and the thrust plate 39.

[0097] The inner end of the pressure plate 32 is formed with a bent portion 32a that is bent from the inner end of the pressure plate 32 toward the transmission 3, and the bent portion 32a protrudes toward the transmission 3 through the opening 27a and abuts against the operation plate 41.

[0098] 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.

[0099] The inner ring of the release bearing 40 is in contact with the operation plate 41 which rotates together with the clutch output member 27, and the outer ring and inner ring rotate relative to each other, thereby moving the operation plate 41 in the direction of the central axis of rotation while allowing the operation plate 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.

[0100] In the release mechanism 36, 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.

[0101] 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 .

[0102] When the thrust plate 39 is pressed toward the clutch output member 27, the release bearing 40 presses the operation plate 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.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] 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 .

[0108] In this way, when the wet clutch 25 is engaged, 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.

[0109] As a result, 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 and transmitting the power of the internal combustion engine 1 to the transmission 3 via the wet clutch 25.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] 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.

[0118] In this state, the power of the drive wheels 6L, 6R is transmitted to the transmission 3 via the drive shafts 5L, 5R and the differential, 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.

[0119] 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.

[0120] 3, 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 intermediate cylindrical portion 27D and the inner cylindrical portion 27F of the clutch output member 27.

[0121] The inner disc portion 27E of the clutch output member 27 is arranged in the working space 43, and multiple through holes 27b are formed in the inner disc portion 27E (see FIG. 5). The through holes 27b face the through holes 22a and the screw hole 1a of the damper input member 22 in the direction of the central axis of rotation.

[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] As shown in FIG. 7, specifically, the working space 43 and the through hole 27b are sized to accommodate a tool 44 and the bolts 9B for assembling the damper input member 22 to the crankshaft 1B with the bolts 9B.

[0124] On the other hand, 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, and 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, 11C, 11D, 11E, 11F, etc.

[0125] 4 and 5 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.

[0126] 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.

[0127] 3, shaft mounting portion 22A is disposed inside bearing support portion 10f. An annular oil seal 12B is provided between outer circumferential portion 22d of shaft mounting portion 22A of damper input member 22 and bearing support portion 10f of right case portion 10A.

[0128] That is, the oil seal 12B is arranged between the portion of the damper input member 22 between the inner end portion of the damper input member 22 (the portion where the outer ring of the bearing 11H abuts) and the outer end portion of the damper input member 22 (the portion that holds the coil spring 24 of the spring holding portion 22D) and the right case portion 10A.

[0129] In this embodiment, outer circumferential portion 22d of shaft attachment portion 22A forms a portion of the damper input member between the outer end and inner end of the damper input member.

[0130] An end portion of the intermediate cylindrical portion 27D of the clutch output member 27 on the transmission 3 side is disposed inside the bearing support portion 10g. An oil seal 12C is provided between an outer peripheral portion 27c of the intermediate cylindrical portion 27D and the left case portion 10B.

[0131] That is, the oil seal 12C is arranged between the part of the clutch output member 27 between the outer end of the clutch output member 27 (the part of the outer disc portion 27A to which the driven gear 29 is attached) and the inner end of the clutch output member 27 (the inner cylindrical portion 27F to which the shaft portion 3a of the flywheel 3C is spline-fitted) and the right case portion 10A.

[0132] In this embodiment, the outer peripheral portion 27c of the intermediate cylindrical portion 27D forms a portion of the clutch output member between the outer end and the inner end of the clutch output member.

[0133] An end of intermediate cylindrical portion 27D of clutch output member 27 on the internal combustion engine 1 side is disposed so as to fit into the inner diameter side of inner cylindrical portion 22B of damper input member 22. An oil seal 12D is provided between inner cylindrical portion 22B of damper input member 22 and intermediate cylindrical portion 27D of clutch output member 27.

[0134] That is, oil seal 12D is disposed between the portion of the damper input member between the inner end of damper input member 22 and the outer end of damper input member 22, and the portion of the clutch output member between the outer end of clutch output member 27 and the inner end of clutch output member 27.

[0135] In this embodiment, the oil seals 12B, 12C, and 12D 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, 12C, and 12D.

[0136] That is, in this embodiment, the through hole 22a is located inside the work space 43 where the work of attaching the power transmission device 4 to the crankshaft 1B is performed, and the oil seals 12B, 12C, and 12D are located radially outward from the work space 43.

[0137] In this embodiment, the oil seal 12C constitutes a first oil seal, and the oil seal 12B constitutes a second oil seal.

[0138] 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.

[0139] 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.

[0140] First, as shown in FIG. 6, the unitized power transmission device 4 is prepared before being attached to the crankshaft 1B.

[0141] To attach the unitized power transmission device 4 to the internal combustion engine 1, the position of the case 10 is aligned with the engine body 1A of the internal combustion engine 1, and the shaft attachment portion 22A is rotated so that the position of the through hole 22a of the shaft attachment portion 22A matches the position of the threaded hole 1a of the crankshaft 1B, thereby aligning the position of the through hole 22a with the position of the threaded hole 1a.

[0142] 7, after the bolt 9B is fitted into the threaded hole 1a through the through hole 22a, a tool 44 is inserted into the working space 43, and the bolt 9B is screwed into the threaded hole 1a using the tool 44. This operation is repeated the number of times equal to the number of threaded holes 1a (six in this embodiment).

[0143] 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.

[0144] Next, as shown in FIG. 3, the transmission 3 to which the flywheel 3C and the gear-changing clutch 3A are attached is fitted by inserting the shaft portion 3a of the flywheel 3C into the inner cylindrical portion 27F of the clutch output member 27 and spline-fitting it, and then fitting the case of the transmission 3 to the case 10.

[0145] Then, the engine body 1A, the case 10, and the case of the transmission 3 are fastened together with bolts (not shown) to assemble the power transmission device 4 so that it is sandwiched between the internal combustion engine 1 and the transmission 3.

[0146] In this way, the power transmission device 4 is assembled to the internal combustion engine 1 and the transmission 3. The motor generator 2 may be connected to the power transmission device 4 before the power transmission device 4 is attached to the internal combustion engine 1, or may be connected to the power transmission device 4 after the power transmission device 4 is attached to the internal combustion engine 1 and the transmission 3. The power transmission device 4 is attached to the internal combustion engine 1.

[0147] 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.

[0148] In addition, the axial length in the direction of the central axis of rotation can be shortened, and the drive gear 2B, damper 21, wet clutch 25, biasing member 28, driven gear 29, and release mechanism 36 can be accommodated in the case 10, so the axial length of the internal combustion engine 1 and transmission 3 in the direction of the central axis of rotation can be shortened, and the hybrid vehicle can be made more compact.

[0149] 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 the hybrid vehicle of this embodiment has a case 10 that houses a wet clutch 25, and a damper 21 that is housed in the case 10 and is arranged between the wet clutch 25 and the internal combustion engine 1, and absorbs rotational fluctuations of the internal combustion engine 1.

[0150] The damper 21 includes a damper input member 22 whose inner end is connected to the internal combustion engine 1 and to which the power of the internal combustion engine 1 is transmitted, a damper output member 23 capable of transmitting the power of the internal combustion engine 1 to the wet clutch 25, and a coil spring 24 arranged circumferentially between the damper input member 22 and the damper output member 23.

[0151] The wet clutch 25 is configured to include a clutch input member 26 that is provided integrally with the damper output member 23 and has an input side friction plate 30 provided at its inner end, and a clutch output member 27 that has an output side friction plate 31 that can be connected and disconnected to the input side friction plate 30 at its outer end, has an inner end connected to the transmission 3, and rotates integrally with the shaft portion 3 a of the flywheel 3C of the transmission 3.

[0152] At the inner end side of the clutch output member 27, a work space 43 is opened, in which the damper 21 can be assembled to the internal combustion engine 1.

[0153] An oil seal 12B is arranged between the outer peripheral portion 22d of the shaft mounting portion 22A of the damper input member 22 and the case 10, and an oil seal 12C is arranged between the outer peripheral portion 27c of the intermediate cylindrical portion 27D of the clutch output member 27 and the case 10.

[0154] In addition, the housing space 45 of the case 10, which houses the damper 21 and the wet clutch 25, is liquid-tightly sealed from the working space 43 by the oil seal 12B and the oil seal 12C.

[0155] This allows a working space 43 to be formed in which bolts 9B and tools 44 can be inserted into the power transmission device 4 while lubricating oil is sealed in the case 10, and the tools 44 can be accessed from the transmission 3 side to assemble the power transmission device 4 to the internal combustion engine 1.

[0156] In addition, the flywheel 3C can be accessed from the transmission 3 side to the working space 43, and the power transmission device 4 can be assembled to the transmission 3.

[0157] Therefore, the power transmission device 4 can be easily assembled between the internal combustion engine 1 and the motor generator 2 and the transmission 3. As a result, the workability of assembling the power transmission device 4 can be improved.

[0158] Furthermore, by disposing the damper 21 in the case 10, the damper 21 and the wet clutch 25 can be made into an integrated structure, thereby shortening the axial length of the power transmission device 4 in the direction of the central axis of rotation, and making it possible to miniaturize the power transmission device 4.

[0159] Therefore, the axial length of the internal combustion engine 1 and the transmission 3 in the direction of the central axis of rotation (vehicle width direction) can be shortened by the amount that the power transmission device 4 can be made smaller, thereby enabling the hybrid vehicle to be made smaller.

[0160] As a result, the power transmission device 4 can be made smaller, and the damper 21 can absorb fluctuations in rotation of the internal combustion engine 1.

[0161] Furthermore, by fastening the damper 21 and the crankshaft 1B with bolts 9B instead of splines, it is possible to suppress the generation of abnormal noise due to backlash in the rotational direction of the crankshaft 1B and wear due to vibration of the crankshaft 1B under combustion pressure.

[0162] Furthermore, the power transmission device 4 of the hybrid vehicle of this embodiment has a drive gear 2B to which the power of the motor generator 2 is input, and a driven gear 29 that is provided at the outer end of the clutch output member 27 and meshes with the drive gear 2B.

[0163] The driven gear 29 and the coil spring 24 are arranged side by side in the direction of the rotational axis, and an input side friction plate 30 and an output side friction plate 31 are arranged radially inward of the driven gear 29 .

[0164] This allows the axial length of the power transmission device 4 in the direction of the rotational center axis to be further shortened, thereby enabling further miniaturization of the power transmission device 4. As a result, the hybrid vehicle can be further miniaturized.

[0165] 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]

[0166] 1. Internal combustion engine 2 Motor generator (rotating electric machine) 2B Drive gear 3-speed 3a Shaft (rotating axis) 4 Power transmission device 10 cases 12B Oil seal (second oil seal) 12C Oil seal (first oil seal) 21 Damper 22 Damper input member 22d Outer periphery (portion of the damper input member between the outer end and inner end of the damper input member) 23 Damper output member 24 Coil spring (elastic member) 25 Wet clutch (clutch) 26 Clutch input member 27 Clutch output member 27c Outer periphery (portion of the clutch output member between the outer end and the inner end of the clutch output member) 29 Driven gear 30 Input side friction plate (first friction plate) 31 Output side friction plate (second friction plate) 43 workspace 45 Containment Space

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 housed in the case and disposed between the clutch and the internal combustion engine, for absorbing rotational fluctuations of the internal combustion engine; the damper includes a damper input member having an inner end connected to the internal combustion engine and to which power of the internal combustion engine is transmitted, a damper output member capable of transmitting power of the internal combustion engine to the clutch, and an elastic member arranged between the damper input member and the damper output member in the circumferential direction, the clutch is configured to include a clutch input member that is provided integrally with the damper output member and has a first friction plate provided at an inner end thereof, and a clutch output member that is provided at an outer end thereof with a second friction plate that can be connected to and disconnected from the first friction plate, and has an inner end connected to the transmission and rotates integrally with a rotary shaft of the transmission, a work space where an assembly operation for assembling the damper to the internal combustion engine can be performed is opened on an inner end side of the clutch output member, a first oil seal is disposed between the damper input member and the case, a second oil seal is disposed between the clutch output member and the case; A power transmission device for a hybrid vehicle, characterized in that the housing space of the case in which the damper and the clutch are housed is liquid-tightly sealed from the working space by the first oil seal and the second oil seal.

2. a drive gear to which power of the rotating electric machine is input; a driven gear provided at an outer end of the clutch output member and meshing with the drive gear, The driven gear and the elastic member are arranged side by side in the direction of the rotational axis of the clutch, 2. The power transmission device for a hybrid vehicle according to claim 1, wherein the first friction plate and the second friction plate are disposed radially inward of the driven gear.

Images