Power transmission system for hybrid vehicles

Abstract

To provide a power transmission system for a hybrid vehicle that can improve the degree of freedom in the placement of the actuator that operates the release member. [Solution] The power transmission device 4 of the hybrid vehicle includes a wet clutch capable of disconnecting and reconnecting power transmission between the internal combustion engine 1 and the transmission 3, a drive gear and a driven gear that transmit power between the motor generator and the transmission, a release mechanism 36 that engages and disengages the wet clutch, and an electric motor 43 that operates the release mechanism 36. The release mechanism 36 moves in the direction of the rotation center axis of the wet clutch by rotating around the rotation center axis C1 of the wet clutch, thereby engaging and disengaging the wet clutch. A link mechanism 41 having a rod 47 is arranged between the electric motor 43 and the release mechanism 36, and the link mechanism 41 converts the power of the electric motor 43 into rotational motion of the release mechanism 36.

Description

Technical Field

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

Background Art

[0002] An automatic clutch device capable of connecting and disconnecting power between an internal combustion engine and a transmission is known (see Patent Document 1).

[0003] The automatic clutch device described in Patent Document 1 releases the clutch engagement between the flywheel and the clutch disc by pressing and moving the release bearing toward the diaphragm spring by an axial force generating mechanism.

[0004] The axial force generating mechanism is formed by an electric motor disposed around the outer periphery of the axial end portion of the input shaft in the transmission and a rotation / linear motion conversion mechanism that converts the rotational motion of the rotor of the electric motor into the linear motion of the release bearing.

[0005] The rotation / linear motion conversion mechanism is formed by a plurality of annular cam plates arranged in tandem on the input shaft and a torque cam mechanism incorporated between a pair of opposing cam plates.

[0006] A spur gear is provided on the rotor of the electric motor, and this spur gear is formed to have a larger diameter than the spur gear of the rotor and meshes with the spur gear that rotates the cam plate.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] However, in the automatic clutch device described in Patent Document 1, the spur gear of the rotor of the electric motor is meshed with the spur gear on the cam plate side, so the electric motor is installed close to the circumference of the cam plate.

[0009] Therefore, if other components are placed around the cam plate, it is necessary to ensure that the electric motor does not interfere with these other components, which may restrict the placement of the electric motor.

[0010] This invention has been made in view of the above circumstances, and aims to provide a power transmission device for a hybrid vehicle that can improve the degree of freedom in the arrangement of the actuator that operates the release member. [Means for solving the problem]

[0011] The present invention relates to a power transmission device for a hybrid vehicle comprising: a clutch disposed between an internal combustion engine and a transmission, capable of disconnecting and reconnecting the transmission of power between the internal combustion engine and the transmission; a pair of reduction gears that transmit power between a rotating electric machine and the transmission; a release member that engages and disengages the clutch; and an actuator that operates the release member, wherein the release member moves in the direction of the rotation center axis of the clutch by rotation around the rotation center axis of the clutch, thereby engaging and disengaging the clutch, characterized in that a link mechanism having a rod is disposed between the actuator and the release member, and the link mechanism converts the power of the actuator into rotational motion of the release member. [Effects of the Invention]

[0012] As described above, the present invention makes it possible to improve the degree of freedom in the placement of the actuator that operates the release member. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is a cross-sectional view of a power transmission device arranged between an internal combustion engine and a transmission according to one embodiment of the present invention. [Figure 2] Figure 2 is a view of the driven gear and pressing plate of a power transmission device according to one embodiment of the present invention, as seen from the internal combustion engine side. [Figure 3] Figure 3 is a view of the drive gear, driven gear, and link mechanism of a power transmission device according to one embodiment of the present invention, as seen from the transmission side. [Figure 4] Figure 4 is a view from above of the drive gear, driven gear, damper, and link mechanism of a power transmission device according to one embodiment of the present invention. [Figure 5] Figure 5 is a cross-sectional view of the rod and its surroundings in a power transmission device according to one embodiment of the present invention. [Figure 6] Figure 6 is a longitudinal cross-sectional view of the cam plate and its surrounding area of ​​a power transmission device according to one embodiment of the present invention. [Figure 7] Figure 7 shows the state of the link mechanism when the cam plate of a power transmission device according to one embodiment of the present invention is rotated to the wet clutch engagement position. [Figure 8] Figure 8 shows the state of the link mechanism when the cam plate of a power transmission device according to one embodiment of the present invention is rotated to the disengagement position of the wet clutch. [Figure 9] Figure 9 shows the cam groove of the cam plate and the cam groove of the thrust plate of a power transmission device according to one embodiment of the present invention. [Modes for carrying out the invention]

[0014] A hybrid vehicle power transmission device according to one embodiment of the present invention comprises a clutch positioned between an internal combustion engine and a transmission, capable of disconnecting and reconnecting power transmission between the internal combustion engine and the transmission; a pair of reduction gears that transmit power between a rotating electric machine and a transmission; a release member that engages and disengages the clutch; and an actuator that operates the release member. The release member moves in the axial direction of the clutch's rotation center by rotation around the clutch's rotation center axis, thereby engaging and disengaging the clutch. A link mechanism having a rod is positioned between the actuator and the release member, and the link mechanism converts the power of the actuator into rotational motion of the release member.

[0015] As a result, the power transmission device of the hybrid vehicle according to one embodiment of the present invention can improve the degree of freedom in arranging an actuator that operates a release member.

Example

[0016] Hereinafter, the power transmission device of the hybrid vehicle according to one embodiment of the present invention will be described with reference to the drawings.

[0017] FIGS. 1 to 9 are diagrams showing a power transmission device of a hybrid vehicle according to one embodiment of the present invention.

[0018] First, the configuration will be described. In FIGS. 1 to 9, the vertical, front-rear, and left-right directions are based on the power transmission device in the state arranged in the hybrid vehicle. The front-rear direction of the hybrid vehicle is the front-rear direction, the left-right direction (vehicle width direction) of the hybrid vehicle is the left-right direction, and the vertical direction (height direction) of the hybrid vehicle is the vertical direction.

[0019] As shown in FIG. 1, the hybrid vehicle has an internal combustion engine 1, a motor generator 2, and a transmission 3. A power transmission device 4 is arranged between the internal combustion engine 1 and the transmission 3.

[0020] The power transmission device 4 has the internal combustion engine 1 attached to one side and the transmission 3 attached to the other side, and connects the internal combustion engine 1 and the transmission 3.

[0021] The internal combustion engine 1 has a rotatable crankshaft 1A extending in the vehicle width direction (left-right direction). The internal combustion engine 1 converts thermal energy into mechanical energy by burning fuel, rotates the crankshaft 1A around the rotation center axis, and transmits power to the transmission 3 via the power transmission device 4.

[0022] The motor-generator 2 is positioned on the internal combustion engine 1 side relative to the power transmission device 4. The motor-generator 2 is located behind the internal combustion engine 1 and is fixed to the cylinder block (not shown) and the power transmission device 4 of the internal combustion engine 1. The motor-generator 2 transmits power to the transmission 3 via the power transmission device 4, while also having a regenerative function that generates electricity using the power transmitted from the transmission 3 via the power transmission device 4.

[0023] Specifically, the motor generator 2 has the function of an electric motor that generates power using electricity supplied from a battery (not shown) via an inverter (not shown), and the function of a generator that performs regenerative power generation using rotational force (reverse driving force) input from a drive wheel (not shown).

[0024] The inverter, controlled by an ECU (not shown), converts DC power supplied from the battery into three-phase AC power and supplies it to the motor generator 2, and converts the three-phase AC power generated by the motor generator 2 into DC power to charge the battery. The battery is composed of a secondary battery, such as a lithium-ion battery.

[0025] In this embodiment, the inverter and battery may be integrated with the motor generator 2, or they may be unitized and attached to the internal combustion engine 1. The motor generator 2 in this embodiment constitutes a rotating electric machine.

[0026] The transmission 3 includes a torque converter 5 as a fluid coupling, a forward / reverse switching mechanism (not shown), and a gear shifting mechanism (not shown).

[0027] The torque converter 5 has a torque fluctuation absorption function and a torque amplification function for the driving torque transmitted from at least one of the internal combustion engine 1 and the motor generator 2, and transmits power to the transmission mechanism.

[0028] The transmission mechanism changes the power (rotation) transmitted from at least one of the internal combustion engine 1 and the motor generator 2, and transmits it to the left and right drive wheels via the left and right drive shafts through a differential (not shown).

[0029] The transmission mechanism consists of a continuously variable transmission (CVT), for example. However, the transmission mechanism is not limited to CVTs.

[0030] In the case of a stepped transmission, a transmission clutch may be provided instead of the torque converter 5. The transmission clutch mechanically disengages when switching gears and mechanically engages when a gear change is achieved. In other words, when the transmission clutch 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 power transmission.

[0031] The power transmission device 4 is positioned between the internal combustion engine 1 and the transmission 3, and transmits power from the motor generator 2 to the transmission 3. It also has a wet clutch 25 (described later) that can disconnect and reconnect power between the internal combustion engine 1 and the transmission 3.

[0032] The power transmission device 4 has a thin, flat shape in the direction of the rotational axis (the direction in which C1 extends, as described later), and is equipped with a case 10 that forms the outer shell. The case 10 is divided in the left-right direction and has a right case section 10A located on the internal combustion engine 1 side and a left case section 10B located on the transmission 3 side.

[0033] Bosses 10a and 10b are provided at the outer ends of the right case section 10A and the left case section 10B, respectively, and the bosses 10a and 10b are fastened together by bolts 9A. This integrates the right case section 10A and the left case section 10B.

[0034] The case 10 is positioned between the internal combustion engine 1 and the transmission 3, and is coupled to the internal combustion engine 1 and the transmission 3.

[0035] The right case section 10A and the left case section 10B are provided with cylindrical bearing support sections 10c and 10d, respectively, and the drive shaft 12A of the drive gear 12 is rotatably supported by the bearing support sections 10c and 10d via bearings 11A and 11B.

[0036] An opening 10e is formed in the right-side case portion 10A, and the drive shaft 12A into which the motor shaft 2A of the motor generator 2 is inserted and connected is positioned to protrude from the opening 10e to the outside (right side) of the case 10. An oil seal 13A is provided between the opening 10e and the drive shaft 12A, and the space between the opening 10e and the drive shaft 12A is closed by the oil seal 13A.

[0037] The drive shaft 12A of the drive gear 12 is formed in a hollow shape with an inner circumferential spline. The outer circumference of the motor shaft 2A of the motor generator 2 has an outer circumferential spline, and the motor shaft 2A is spline-fitted to the drive shaft 12A. As a result, the drive gear 12 is driven by the motor generator 2.

[0038] The case 10 houses a damper 21. The damper 21 includes a damper input member 22, a damper output member 23, and a coil spring 24.

[0039] The damper 21 is positioned in the same location as the bearing support portion 10c in the axial direction (the direction in which C1 extends, as described later). In other words, the bearing support portion 10c is positioned radially outward from 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.

[0040] The damper 21 is a thin, disc-shaped component in the axial direction, positioned within the case 10 on the internal combustion engine 1 side along the right-side case portion 10A. 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 1A by a plurality of bolts 9B.

[0041] The shaft mounting portion 22A has multiple through holes 22a through which bolts 9B pass, and these holes are formed to coincide with the positions of the threaded holes 1a on the crankshaft 1A. The through holes 22a are opposite the threaded holes 1a in the direction of the rotational axis of the damper 21.

[0042] The shaft mounting portion 22A is attached to the crankshaft 1A by a bolt 9B inserted into a through hole 22a, which is then screwed into a threaded hole in the crankshaft 1A. As a result, the damper input member 22 rotates together with the crankshaft 1A.

[0043] The damper input member 22 has a disc portion 22B that extends radially outward in a disc shape from the shaft mounting portion 22A, and a spring holding portion 22C provided at the outer end of the disc portion 22B and holding a coil spring 24 which is arranged circumferentially together with the damper output member 23.

[0044] The shaft mounting portion 22A, the disc portion 22B, and the spring holding portion 22C rotate together with the crankshaft 1A.

[0045] The coil spring 24 is positioned so as to be expandable and contractible in the direction of the coil axis between the outer end of the damper input member 22 and the outer end of the damper output member 23, with its coil axis aligned along the circumferential direction.

[0046] The driving force between the damper input member 22 and the damper output member 23 is transmitted via a coil spring 24. The elastic deformation of the coil spring 24 allows for relative rotational displacement between the damper input member 22 and the damper output member 23, thereby absorbing minute fluctuations in the driving force.

[0047] Specifically, when the damper input member 22 rotates due to the rotation of the crankshaft 1A, the rotation of the damper input member 22 is transmitted to the damper output member 23 via the coil spring 24. As a result, the damper output member 23 rotates together with the damper input member 22.

[0048] Here, when rotational fluctuations (torque fluctuations) occur in the rotation of 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, thereby absorbing the rotational fluctuations of the internal combustion engine 1 without transmitting them from the damper input member 22 to the damper output member 23.

[0049] In other words, the coil spring 24 elastically deforms in the direction of the coil axis between the damper input member 22 and the damper output member 23 so as to allow relative displacement of the damper input member 22 and the damper output member 23 in the rotational direction, thereby absorbing vibrations of rotational speed while transmitting torque.

[0050] The case 10 houses a wet clutch 25. The wet clutch 25 includes a clutch input member 26, a driven gear 27 which constitutes a clutch output member, and a biasing member 28.

[0051] The wet clutch 25 is positioned on the transmission 3 side relative to the damper 21. That is, the damper 21 is positioned between the wet clutch 25 and the internal combustion engine 1 in the direction of the rotational axis of the wet clutch 25. The wet clutch 25 in this embodiment constitutes a clutch.

[0052] 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.

[0053] The driven gear 27 is positioned on the transmission 3 side relative to the clutch input member 26, and has teeth 27a formed on its outer circumference that mesh with the drive gear 12.

[0054] Here, the rotational axis C1 of the torque converter 5, the rotational axis of the crankshaft 1A, the rotational axis of the damper 21, and the rotational axis of the wet clutch 25 are all the same rotational axis C1.

[0055] The crankshaft 1A, torque converter 5, damper 21, and wet clutch 25 are arranged so that their rotational axis C1 is horizontal. Hereafter, the direction in which the rotational axis C1 of each of these components extends will be referred to as the rotational axis direction (the same applies to the rotational axis direction described above).

[0056] The driven gear 27 is connected to the motor generator 2 via the drive gear 12 and operates in conjunction with the motor generator 2. The driven gear 27 is formed with a larger diameter than the drive gear 12, and the driving force of the motor generator 2 is reduced by the driven gear 27. In other words, the drive gear 12 and the driven gear 27 are gears for reduction.

[0057] In this embodiment, the drive gear 12 and the driven gear 27 constitute a pair of reduction gears. The drive gear 12 constitutes a drive reduction gear, and the driven gear 27 constitutes a driven reduction gear.

[0058] In this embodiment, the drive gear 12 is positioned so that its rotational axis C2 is horizontal, and the rotational axis C1 of the driven gear 27 and the rotational axis C2 of the drive gear 12 are parallel.

[0059] An input-side friction plate 30, an output-side friction plate 31, and a pressing plate 32 are arranged in the inner space (inner diameter side space) of the cylindrical clutch input member 26 (see Figure 6). In this embodiment, the input-side friction plate 30 and the output-side friction plate 31 constitute a friction member.

[0060] Multiple input-side friction plates 30 are spline-fitted to the inner circumference of the clutch input member 26. The input-side friction plates 30 are rotatable integrally with the clutch input member 26 and are also movable relative to the clutch input member 26 in the direction of the rotational center axis. The output-side friction plate 31 is attached to the outer circumference (plate holding portion 32B) of the pressing plate 32.

[0061] As shown in Figure 1, the driven gear 27 has a toothed portion 27a formed on its outer end (outer peripheral edge), an outer disc portion 27A whose outer edge is connected to the inner diameter portion of the toothed portion 27a closer to the damper 21, and an inner disc portion 27B provided at the inner end of the outer disc portion 27A, which is formed to be longer in the axis direction of the rotation center than the outer disc portion 27A.

[0062] The inner disc portion 27B is provided with a shaft portion 27C, which protrudes from the inner disc portion 27B toward the internal combustion engine 1. The shaft portion 27C is positioned in the same location as the damper 21 in the axis direction of the rotation center and is recessed into the inner diameter side of the damper 21, and is rotatable relative to the damper 21 via a bearing 11C.

[0063] The torque converter 5 is fastened to the driven gear 27 via a drive plate 5A, and the drive plate 5A is fastened to the driven gear 27 by bolts 9C.

[0064] The torque converter 5 is connected to the drive plate 5A by bolts 9D at its outer diameter, forming a fluid coupling that transmits power between the power transmission device 4 and the transmission 3 via oil.

[0065] The torque converter 5 is capable of transmitting power to the forward / reverse switching mechanism of the transmission 3. The forward / reverse switching mechanism comprises a forward clutch (not shown) that enables the hybrid vehicle to travel in the forward direction, a reverse brake (not shown) that enables travel in the reverse direction, and a planetary gear mechanism (not shown) positioned between the forward brake and the reverse brake.

[0066] Each CVT comprises a primary sheave (not shown), a secondary sheave, and a belt wrapped around the primary and secondary sheaves. By changing the groove width of the primary and secondary sheaves, the gear ratio is changed, and power from the power transmission device 4 is transmitted to the wheels (not shown).

[0067] The biasing member 28 includes an annular pressing plate 32, a disc spring 33, and an annular spring fixing flange 34. In this embodiment, the pressing plate 32 constitutes the pressing member.

[0068] As shown in Figures 2 and 6, the pressing plate 32 has a pressing portion 32A, a plate holding portion 32B that extends cylindrically from the radially inner end of the pressing portion 32A toward the transmission 3, and a bent portion 32C that extends radially inward from the left end (transmission 3 side end) of the plate holding portion 32B and bends conically so as to bulge slightly toward the internal combustion engine 1.

[0069] The pressing plate 32 has a plurality of bent portions 32D that extend radially inward from the bent portion 32C and are then bent toward the driven gear, and are spaced apart in the circumferential direction; a plurality of first claw portions 32E that are located between the bent portions 32D in the circumferential direction and extend radially inward from the bent portion 32C than the bent portions; and a plurality of second claw portions 32F that are located between the bent portions 32D in the circumferential direction and extend radially inward from the bent portion 32C than the first claw portions.

[0070] As shown in Figure 6, the output-side friction plate 31 is attached to the cylindrical plate holder 32B so as to surround it. The output-side friction plate 31 is rotatable integrally with the plate holder 32B and is also movable in the axis direction of its rotational center relative to the plate holder 32B. As a result, the output-side friction plate 31 rotates integrally with the pressing plate 32.

[0071] The input friction plate 30 and the output friction plate 31 are arranged alternately in the direction of the rotational axis, allowing for frictional contact.

[0072] The outer disc portion 27A of the driven gear 27 has a plurality of through holes 27b that are spaced equally apart in the circumferential direction, and the bent portion 32D is inserted through the through holes 27b.

[0073] The through-hole 27b is formed as an elongated hole that is longer in the circumferential direction than in the radial direction (see Figure 2), and the through-hole 27b surrounds the bent portion 32D so as not to contact the bent portion 32D.

[0074] As shown in Figures 2 and 6, a cylindrical engagement portion 27c is formed on the side of the driven gear 27 facing the internal combustion engine 1. The cylindrical engagement portion 27c protrudes from the side of the driven gear 27 facing the internal combustion engine 1 toward the internal combustion engine 1 and extends in an annular shape in the circumferential direction of the driven gear 27. Note that the input side friction plate 30 and the output side friction plate 31 are omitted from the illustration in Figure 2.

[0075] The radial inner end of the first claw portion 32E abuts against the cylindrical engaging portion 27c, and the pressing plate 32 is positioned radially relative to the driven gear 27 by the cylindrical engaging portion 27c.

[0076] As shown in Figure 2, the cylindrical engaging portion 27c has slits 27d formed at equal intervals in the circumferential direction, and the radial inner end of the second claw portion 32F is engaged with the slits 27d. As a result, the pressing plate 32 is positioned in the circumferential direction of the driven gear 27 by the slits 27d.

[0077] In other words, the pressing plate 32 is positioned in the radial and circumferential directions of the driven gear 27 by the cylindrical engaging portion 27c and the slit 27d such that the bent portion 32D does not come into contact with the through hole 27b, and is mounted so as to be immovable in the radial and circumferential directions of the driven gear 27.

[0078] In this embodiment, the bent portion 32D constitutes a receiving portion, and the first claw portion 32E, the second claw portion 32F, the cylindrical engaging portion 27c, and the slit 27d constitute a support portion. The first claw portion 32E and the second claw portion 32F constitute a claw portion, and the cylindrical engaging portion 27c and the slit 27d constitute an engaging portion.

[0079] The disc spring 33 is positioned to the right of the pressure plate 32 with its outer end on the left and its inner end on the right, and its outer end contacts the pressure plate 32, biasing the pressure plate 32 toward the transmission 3.

[0080] In other words, the pressing plate 32 is pressed towards the transmission 3 by the biasing force of the disc spring 33. The disc spring 33 in this embodiment constitutes the first spring member.

[0081] The spring fixing flange 34 has a cylindrical portion that extends axially through the inner diameter of the inner end of the disc spring 33, and the right end edge of the cylindrical portion is wider than the inner diameter of the disc spring 33, pressing the inner end of the disc spring 33 from the right side toward the driven gear 27.

[0082] The disc spring 33 is mounted in a pre-pressurized state by being pressed against the spring fixing flange 34, thereby generating a biasing force that biases the pressing plate 32 toward the transmission 3, with its inner end as the pivot point.

[0083] The spring fixing flange 34 is superimposed on the outer disc portion 27A of the driven gear 27 radially inward of the disc spring 33, with the sealing member sandwiched in between (see Figure 1), and is fastened and fixed to the inner disc portion 27B from the internal combustion engine 1 side by bolts 9E.

[0084] The input friction plate 30 and the output friction plate 31 are arranged alternately in the direction of the rotation center axis. The input friction plate 30 and the output friction plate 31 move in the direction of the rotation center axis so that they alternate between a frictional contact state and a non-contact state.

[0085] The biasing member 28 is a member that maintains the state in which the clutch input member 26 and the driven gear 27 are connected via the input-side friction plate 30 and the output-side friction plate 31, and biases the input-side friction plate 30 and the output-side friction plate 31 to press against the driven gear 27 so as to sandwich them between the driven gear 27. The wet clutch 25 in this embodiment is normally closed.

[0086] When the input friction plate 30 and the output friction plate 31 come into contact and friction force is generated, the clutch input member 26 and the driven gear 27 can transmit power via the input friction plate 30 and the output friction plate 31.

[0087] As a result, the power from the internal combustion engine 1 is transmitted to the torque converter 5 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 driven gear 27.

[0088] Furthermore, when the motor generator 2 is driven, the power of the motor generator 2 is transmitted to the torque converter 5 via the motor shaft 2A, drive shaft 12A, drive gear 12, and driven gear 27. In other words, the motor generator 2 can transmit its power to the torque converter 5 without going through the wet clutch 25.

[0089] As shown in Figures 1 and 6, a bearing fixing flange 35 is attached to the left case portion 10B, and the bearing fixing flange 35 constitutes a part of the left case portion 10B.

[0090] The bearing fixing flange 35 has an annular portion 35A that abuts against the inner wall surface of the left case portion 10B, and a cylindrical portion 35B that extends cylindrically from the radially inner end of the annular portion 35A toward the driven gear 27 side (internal combustion engine 1 side), and the annular portion 35A is fixed to the left case portion 10B by bolts (not shown).

[0091] The case 10 houses the release mechanism 36, and the release mechanism 36, wet clutch 25, and damper 21 are arranged in the order of release mechanism 36, wet clutch 25, and damper 21 from the transmission 3 side in the direction of the rotational axis.

[0092] In detail, the clutch input member 26, input-side friction plate 30, output-side friction plate 31, and pressing plate 32 are positioned to the right of the driven gear 27 (one side in the direction of the rotation center axis), while the release mechanism 36 is positioned to the left of the driven gear 27 (the other side in the direction of the rotation center axis).

[0093] In other words, the clutch input member 26, input-side friction plate 30, output-side friction plate 31, and pressing plate 32 and the release mechanism 36 are arranged to the left and right with respect to the driven gear 27. The release mechanism 36 in this embodiment constitutes the release member.

[0094] The release mechanism 36 includes an annular cam plate 37, a ball 38, a thrust plate 39, a release bearing 40, and a link mechanism 41 (see Figure 3).

[0095] The cam plate 37, ball 38, thrust plate 39, and release bearing 40 are positioned radially inward of the teeth 27a of the driven gear 27.

[0096] The cam plate 37, ball 38, and thrust plate 39 are positioned radially at approximately the same location as the input side friction plate 30 and output side friction plate 31, and axially, they are arranged in the order of cam plate 37, ball 38, and thrust plate 39 from the driven gear 27 side.

[0097] The cam plate 37 rotates within a certain range with the rotational axis C1 as the center of rotation by the link mechanism 41.

[0098] As shown in Figure 9, multiple cam grooves 37a are formed on the surface of the cam plate 37 facing the thrust plate 39. The cam grooves 37a are spaced at regular intervals in the circumferential direction around the rotation axis C1 of the cam plate 37, and each extends in the circumferential direction (the rotation direction of the internal combustion engine 1) around the rotation axis C1 of the cam plate 37.

[0099] Each cam groove 37a extends in the circumferential direction of the cam plate 37 (the rotation direction of the internal combustion engine 1), and has an inclined surface in which the depth in the direction of the rotational axis becomes shallower from one end to the other 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 in the circumferential direction.

[0100] Multiple cam grooves 39a are formed on the surface of the thrust plate 39 facing the cam plate 37. The cam grooves 39a are arranged at regular intervals in the circumferential direction around the rotational axis C1 and extend in the circumferential direction around the rotational axis C1 (the rotational direction of the internal combustion engine 1).

[0101] Each cam groove 39a extends in the circumferential direction of the thrust plate 39 (the rotation direction of the internal combustion engine 1), and has an inclined surface in which the depth in the direction of the rotational axis increases from one end to the other in the rotational direction of the internal combustion engine 1. In other words, the depth of the cam groove 39a in the direction of the rotational axis changes from one side to the other in the circumferential direction.

[0102] The cam grooves 37a and 39a house balls 38, and the balls 38 are capable of rolling along the cam grooves 37a and 39a.

[0103] As shown in Figure 6, the thrust plate 39 has a hole into which a pin 42 fixed to the bearing fixing flange 35 is inserted, and the pin 42 engages with the hole, thereby preventing rotation and allowing movement in the axis direction of the rotation center.

[0104] As shown in Figure 6, the release bearing 40 has an outer ring 40A fixed to the cam plate 37 and moves in the direction of the rotational axis in accordance with the movement of the cam plate 37.

[0105] The release bearing 40 has an inner ring 40B that contacts the bent portion 32D of the pressure plate 32 in the direction of the rotational axis, and transmits the movement of the cam plate 37 in the direction of the rotational axis to the pressure plate 32, causing the pressure plate 32 to move in the axial direction.

[0106] In other words, the release bearing 40 applies an operating force in the direction of disengaging the clutch to the bent portion 32D (receiving portion).

[0107] The release bearing 40 allows the pressing plate 32, which rotates integrally with the driven gear 27, to rotate while the outer ring 40A and inner ring 40B rotate relative to each other, thereby moving the pressing plate 32 in the direction of the rotation center axis.

[0108] As shown in Figure 6, a wave washer 29 is provided in a compressed state between the bearing fixing flange 35 and the thrust plate 39. The wave washer 29 biases the thrust plate 39 toward the cam plate 37, and via the ball 38, biases the cam plate 37 toward the driven gear 27, pressing the release bearing 40 against the pressing plate 32. The wave washer 29 eliminates play in the release mechanism 36. In this embodiment, the wave washer 29 constitutes a second spring member.

[0109] As shown in Figure 5, the electric motor 43 that operates the release mechanism 36 is attached to the left case portion 10B by bolts (not shown).

[0110] An opening 10f is formed in the left-side case section 10B, and the motor shaft 43A of the electric motor 43 is inserted into the case 10 through the opening 10f. An oil seal 44A is provided between the motor shaft 43A and the opening 10f, and the space between the opening 10f and the motor shaft 43A is closed by the oil seal 44A.

[0111] A cam drive gear 45 is attached to the tip of the motor shaft 43A, and the cam drive gear 45 is rotated by the electric motor 43.

[0112] The link mechanism 41 is positioned between the electric motor 43, which acts as an actuator, and the release mechanism 36.

[0113] As shown in Figures 4 and 7, the link mechanism 41 includes a cam-driven gear 46 and a rod 47. The cam-driven gear 46 includes an annular rotating member 46A and a cam-driven plate 46B provided on the outer circumference of the rotating member 46A.

[0114] As shown in Figure 1, the rotating member 46A is rotatably mounted to the bearing support portion 10c via a metal bearing 44B. The rotating member 46A faces the drive gear 12 in the direction of the rotational axis and surrounds the drive shaft 12A in the radial direction, and is positioned to have the same rotational axis as the drive gear 12.

[0115] In other words, the cam driven gear 46 has a rotational axis C2 that is radially separated from the rotational axis C1 of the wet clutch 25.

[0116] As shown in Figures 7 and 8, the cam-driven plate 46B protrudes radially outward from the outer circumference of the rotating member 46A within a certain range in the circumferential direction of the rotating member 46A. Teeth 46a are formed on the outer circumference of the cam-driven plate 46B, and these teeth 46a mesh with the cam drive gear 45 of the electric motor 43.

[0117] As a result, when the cam drive gear 45 rotates, the cam driven plate 46B moves circumferentially around the rotation center axis C2, and the rotating member 46A rotates around the rotation center axis C2. In other words, the cam driven gear 46 rotates around the rotation center axis C2.

[0118] One end of the rod 47 is fastened to the circumferential end of the cam-driven plate 46B, indicated by P1 in the figure, via a rotatable joint and a bolt (not shown).

[0119] A projection 37A is provided on the outer circumference of the cam plate 37. The projection 37A extends radially outward from one end connected to the cam plate 37, then extends in the direction of the rotational axis so as to cross the driven gear 27 and the damper 21, and then extends radially outward again to form the other end (see Figure 4).

[0120] The other end of the rod 47 is fastened to the other end of the projection 37A, indicated by P2 in the figure, via a rotatable joint and a bolt (not shown). The rod 47 is a component that transmits the movement of the cam driven gear 46 to the cam plate 37, and is positioned on a plane perpendicular to the rotational axis C1, in a position where no force is generated in the direction that extends the rotational axis C1.

[0121] In other words, the cam driven gear 46 and the cam plate 37 are positioned offset in the direction of the rotational axis C1, but the bending of the protrusion 37A causes them to be positioned on a plane perpendicular to the rotational axis C1.

[0122] When the cam drive gear 46 rotates due to the connection of the rod 47, the power from the cam drive gear 46 is transmitted to the cam plate 37, causing the cam plate 37 to rotate around the rotational axis C1.

[0123] Figure 7 shows the position of the cam driven plate 46B when the wet clutch 25 is engaged, and Figure 8 shows the position of the cam driven plate 46B when the wet clutch 25 is disengaged.

[0124] From the state shown in Figure 7, the electric motor 43 drives the cam drive gear 45, causing the cam driven plate 46B to move around the rotational axis C2 in the R1 direction (the direction in which the clutch is disengaged). As a result, the connection point P1 between the cam driven plate 46B and the rod 47 moves toward the cam plate 37, and the cam plate 37 is pushed by the rod 47 and rotates around the rotational axis C1 in the R1 direction (the direction in which the clutch is disengaged).

[0125] When the cam plate 37 rotates in the R1 direction, the cam grooves 37a and 39a move relative to the ball 38, causing the ball 38 to move from the position of the deeply inclined surface of the cam grooves 37a and 39a to the position of the shallowly inclined surface.

[0126] This increases the gap between the cam plate 37 and the thrust plate 39 in the direction of the rotational axis, pushing the cam plate 37 towards the driven gear 27.

[0127] When the cam plate 37 moves toward the driven gear 27, the release bearing 40 presses the bent portion 32D toward the internal combustion engine 1, moving the pressing plate 32 toward the internal combustion engine 1 against the biasing force of the disc spring 33.

[0128] As a result, the pressing force from the pressing portion 32A of the pressing plate 32 no longer acts on the input-side friction plate 30 and the output-side friction plate 31.

[0129] As a result, a gap is created between the input friction plate 30 and the output friction plate 31, the wet clutch 25 is disengaged, and the power transmitted from the internal combustion engine 1 to the driven gear 27 is interrupted.

[0130] As shown in Figure 8, a stopper claw 46b is provided at one circumferential end of the cam driven plate 46B, and the stopper claw 46b can contact a contact portion 10g (the position of the contact portion 10g is shown by a dashed line) provided on the right case portion 10A. This restricts the rotation of the cam driven gear 46 in the direction R1 that would further disengage the wet clutch 25 from the state in which the wet clutch 25 is disengaged.

[0131] On the other hand, when the cam drive gear 45 is driven by the electric motor 43 from the state shown in Figure 8, and the cam driven plate 46B moves away from the cam plate 37, this movement is transmitted to the cam plate 37 via the rod 47, and the cam plate 37 is pulled by the rod 47 and rotates around the rotational axis C1 in the R2 direction (the direction in which the clutch is engaged).

[0132] When the cam plate 37 is rotated in the R2 direction, the cam grooves 37a and 39a move relative to the ball 38, and the ball 38 moves from the shallow inclined surface position of the cam grooves 37a and 39a to the deep inclined surface position.

[0133] This allows the length of the cam plate 37 and thrust plate 39 in the axial direction of the rotation center to be shortened, and the biasing force of the disc spring 33 pushes the pressure plate 32, release bearing 40, and cam plate 37 towards the transmission 3, causing the pressure plate 32 to move from the internal combustion engine 1 side to the transmission 3 side.

[0134] Therefore, the input-side friction plate 30 and the output-side friction plate 31 are pressed towards the transmission 3 by the pressing plate 32, and the input-side friction plate 30 and the output-side friction plate 31 are sandwiched between the pressing plate 32 and the driven gear 27 (outer disc portion 27A), generating a strong frictional force. As a result, the wet clutch 25 is engaged, and the power of the internal combustion engine 1 is transmitted to the driven gear 27 via the wet clutch 25.

[0135] Furthermore, when the wet clutch 25 is engaged, the damper output member 23 is connected to the torque converter 5 (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 driven gear 27.

[0136] When the wet clutch 25 is engaged, if rotational fluctuations (torque fluctuations) occur in the internal combustion engine 1, the coil spring 24 elastically deforms in the rotational direction of the damper 21, causing the damper input member 22 and the damper output member 23 to rotate relative to each other, thereby absorbing the rotational fluctuations of the internal combustion engine 1.

[0137] A stopper claw 46c is provided at the other end of the cam-driven plate 46B in the circumferential direction, and the stopper claw 46c can contact a contact portion 10h (the position of the contact portion 10h is shown by a dashed line) provided on the right-side case portion 10A.

[0138] This restricts the rotation of the cam-driven gear 46 in the direction R2, which would further engage the wet clutch 25 from the state in which the wet clutch 25 is engaged.

[0139] Furthermore, the circumferential lengths of the cam grooves 37a and 39a are formed to be long, resulting in a large twist angle of the cam plate 37.

[0140] In other words, the circumferential length of the cam grooves 37a and 39a is made long so that, from the state in which the stopper claw 46b contacts the contact portion 10g to the state in which the stopper claw 46c contacts the contact portion 10h, the walls 37b and 39b at one end of the cam grooves 37a and 39a (see Figure 9) and the walls 37c and 39c at the other end of the cam grooves 37a and 39a do not simultaneously collide with the ball 38.

[0141] Therefore, when the wet clutch 25 is disengaged and the stopper claw 46b contacts the contact portion 10g, the ball 38 is positioned on the shallow inclined surface of the cam grooves 37a and 39a, and when the wet clutch 25 is engaged and the stopper claw 46c contacts the contact portion 10h, the ball 38 is positioned on the deep inclined surface of the cam grooves 37a and 39a.

[0142] Thus, the release mechanism 36 includes a cam plate 37, a thrust plate 39 facing the cam plate 37 in the direction of the rotational axis of the wet clutch 25, and cam grooves 37a, 39a and balls 38 provided on the cam plate 37 and thrust plate 39, which convert the rotational motion of the cam plate 37 into motion in the direction of the rotational axis of the wet clutch 25 to engage and disengage the wet clutch. The link mechanism 41 converts the power of the electric motor 43 into rotational motion of the release mechanism 36. Note that rotation means rotating within an angle range smaller than 360°.

[0143] In this embodiment, the cam plate 37 constitutes a drive cam plate, and the thrust plate 39 constitutes a fixed cam plate. The cam grooves 37a, 39a and the ball 38 constitute a ball cam section.

[0144] As shown in Figures 7 and 8, in the link mechanism 41, the first virtual straight line L1 is defined as the virtual straight line connecting the first connection point P1, which connects the cam drive plate 46B of the cam drive gear 46 to one end of the rod 47, and the rotational center axis C2 of the cam drive gear 46. The second virtual straight line L2 is defined as the virtual straight line connecting the second connection point P2, which connects the protruding portion 37A of the cam plate 37 to the other end of the rod 47, to the first connection point P1.

[0145] In this case, the larger the angle formed by the first virtual line L1 and the second virtual line L2 (see Figure 8), the more the cam plate 37 rotates in the direction that disengages the wet clutch 25.

[0146] In other words, the smaller the angle formed by the first virtual line L1 and the second virtual line L2 (see Figure 7), the more the cam plate 37 rotates in the direction that engages the wet clutch 25.

[0147] As shown in Figure 8, when the angle between the first virtual line L1 and the second virtual line L2 is at its maximum, the first connection point P1 is located closer to the rotational axis C1 of the wet clutch 25 than when the angle between the first virtual line L1 and the second virtual line L2 is at its minimum, and the first virtual line L1 and the second virtual line L2 are closer to being a straight line.

[0148] As a result, when the wet clutch 25 is disengaged, most of the force acting from the rod 47 can be received by the rotational center axis C2 of the cam driven gear 46, making it possible to reduce the force of the electric motor 43 required to maintain the disengaged state.

[0149] Furthermore, since the power of the electric motor 43 required to maintain the cut state can be reduced, the power consumption of the electric motor 43 during motor-driven operation, when the internal combustion engine 1 is stopped and the hybrid vehicle is driven by the power of the motor generator 2, can be reduced.

[0150] Furthermore, when the wet clutch 25 shown in Figure 7 is engaged, the angle between the first virtual line L1 and the second virtual line L2 is approximately a right angle, and the direction of movement of the first connection point P1 is the direction in which the second virtual line L2 extends. As a result, the movement of the cam-driven plate 46B can be efficiently converted into the axial movement of the rod 47, and the disengagement and engagement of the wet clutch 25 by the electric motor 43 can be easily controlled.

[0151] As shown in Figure 1, a bearing 11D is provided between the outer circumference of the inner disc portion 27B of the driven gear 27 and the inner circumference of the cylindrical portion 35B of the bearing fixing flange 35 attached to the left case portion 10B, and the driven gear 27 is rotatably supported by the bearing fixing flange 35 (left case portion 10B) via the bearing 11D.

[0152] A bearing fixing flange 48 is press-fitted onto the left side of the inner disc portion 27B, and the inner ring of the bearing 11D is prevented from coming out of the inner disc portion 27B by its left end contacting the outer end of the bearing fixing flange 48.

[0153] Furthermore, the bearing 11D is sandwiched between the outer end of the bearing fixing flange 48 and the outer disc portion 27A of the driven gear 27, and is positioned so as to be immovable in the rotational axis direction by the bearing fixing and the outer disc portion 27A.

[0154] An oil seal 13B is provided to the left of the bearing 11D (outward in the direction of the rotation center axis), and the oil seal 13B is positioned between the outer end of the bearing fixing flange 48 and the inner end of the left side case portion 10B.

[0155] An oil seal 13C is provided between the outer circumference of the shaft mounting portion 22A of the damper 21 and the inner end of the right-side case portion 10A.

[0156] An oil seal 13D is provided between the outer circumference of the shaft mounting portion 22A and the spring fixing flange 34. In other words, the oil seal 13D is provided on the inside of the spring fixing flange 34.

[0157] The oil seals 13B, 13C, and 13D are positioned radially outward from the multiple threaded holes 1a of the crankshaft 1A and the multiple through holes 22a of the shaft mounting portion 22A, and lubricating oil is sealed inside the case 10. Therefore, the inside of the case 10 is liquid-tightly sealed by the oil seals 13B, 13C, and 13D.

[0158] In this embodiment, the power transmission device 4 engages the wet clutch 25 when the hybrid vehicle is driven by the power of the internal combustion engine 1.

[0159] As a result, the power from the internal combustion engine 1 is transmitted to the torque converter 5 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 driven gear 27, and then transmitted from the torque converter 5 to the continuously variable transmission via the forward / reverse switching mechanism.

[0160] Furthermore, during motor-driven operation, when the internal combustion engine 1 is stopped and the hybrid vehicle is driven by the power of the motor generator 2, the wet clutch 25 is disengaged.

[0161] As a result, the power from the motor generator 2 is transmitted to the torque converter 5 via the motor shaft 2A, drive shaft 12A, drive gear 12, and driven gear 27, and then transmitted from the torque converter 5 to the continuously variable transmission via the forward / reverse switching mechanism.

[0162] Furthermore, during hybrid driving, when the hybrid vehicle is driven by the power of the internal combustion engine 1 and the motor generator 2, the wet clutch 25 is engaged, and 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.

[0163] In hybrid driving, the internal combustion engine 1 can be operated in a fuel-efficient manner, and the acceleration performance of the hybrid vehicle can be improved.

[0164] Furthermore, during deceleration (regeneration) of the hybrid vehicle, the wet clutch 25 is disengaged, completely separating the internal combustion engine 1 from the drive wheels.

[0165] This allows the power transmitted from the drive wheels to the power transmission device 4 to be transmitted only to the motor generator 2, enabling efficient regeneration by the motor generator 2.

[0166] In other words, power from the drive wheels is transmitted to the transmission 3 via the left and right drive shafts and differential. Power from the drive wheels is then transmitted from the transmission 3 to the motor generator 2 via the driven gear 27, and regeneration is performed by the motor generator 2.

[0167] During deceleration in this hybrid vehicle, the internal combustion engine 1 and the drive wheels are completely disconnected, so engine braking does not occur. This minimizes energy loss due to engine braking and transmits power from the transmission 3 to the power transmission device 4 solely to the motor generator 2, allowing for efficient regeneration by the motor generator 2.

[0168] Next, the effects of the power transmission system 4 of the hybrid vehicle in this embodiment will be explained. The power transmission device 4 of the hybrid vehicle in this embodiment is located between the internal combustion engine 1 and the transmission 3 and includes a wet clutch 25 capable of disconnecting and reconnecting power transmission between the internal combustion engine 1 and the transmission 3, a drive gear 12 and a driven gear 27 that transmit power between the motor generator 2 and the transmission 3, a release mechanism 36 that engages and disengages the wet clutch 25, and an electric motor 43 that operates the release mechanism 36.

[0169] The release mechanism 36 moves in the direction of the rotational axis of the wet clutch 25 by rotation around the rotational axis C1 of the wet clutch 25, thereby engaging and disengaging the wet clutch 25.

[0170] A linkage mechanism 41 having a rod 47 is positioned between the electric motor 43 and the release mechanism 36, and the linkage mechanism 41 converts the power of the electric motor 43 into rotational motion of the release mechanism 36.

[0171] This allows the electric motor 43 to transmit power to the release mechanism 36 while suppressing interference between the electric motor 43 and surrounding components such as the drive gear 12 arranged around the cam plate 37.

[0172] In other words, since the link mechanism 41 has a long and relatively thin rod 47, by arranging the rod 47 in the narrow space between the electric motor 43 and the cam plate 37, the power of the electric motor 43 can be efficiently transmitted to the release mechanism 36 via the rod 47 in a small space, even if the electric motor 43 is located far away from the release mechanism 36.

[0173] Therefore, constraints on the placement of the electric motor 43 that operates the release mechanism 36 can be suppressed, and the degree of freedom in the placement of the electric motor 43 can be improved.

[0174] Furthermore, according to the power transmission device 4 of the hybrid vehicle of this embodiment, the electric motor 43 has a cam drive gear 45.

[0175] The release mechanism 36 includes a thrust plate 39, a cam plate 37 facing the thrust plate 39 in the direction of the rotational axis of the wet clutch 25, and cam grooves 37a, 39a and balls 38 provided on the thrust plate 39 and the cam plate 37, which convert the rotational motion of the cam plate 37 into motion in the direction of the rotational axis of the wet clutch 25 to engage and disengage the wet clutch 25.

[0176] In addition, the link mechanism 41 has a rotational axis C2 radially separated from the rotational axis C1 of the wet clutch 25, and includes a cam driven gear 46 having teeth 46a that mesh with the drive gear 12, and a rod 47 connected to the cam driven gear 46 and the cam plate 37, which transmits the power of the cam driven gear 46 to the cam plate 37. This allows the power of the electric motor 43 to be transmitted to the release mechanism 36 with a simple configuration.

[0177] Furthermore, the power transmission device 4 of the hybrid vehicle in this embodiment has a biasing member 28 equipped with a disc spring 33 that biases the wet clutch 25 so that the wet clutch 25 is in an engaged state.

[0178] The release mechanism 36 is configured to disengage the wet clutch 25 when the cam plate 37 moves in the rotational axis direction of the wet clutch 25 against the biasing force of the disc spring 33.

[0179] If we define the first virtual line L1 as the virtual line connecting the first connection point P1, which connects the cam driven gear 46 and one end of the rod 47, and the rotational axis C2 of the cam driven gear 46, and define the second virtual line L2 as the virtual line connecting the second connection point P2, which connects the cam plate 37 and the other end of the rod 47, and the first connection point P1, then the larger the angle between the first virtual line L1 and the second virtual line L2, the more the cam plate 37 rotates in the direction of disengaging the wet clutch 25.

[0180] This allows the rod 47 (second virtual line L2) to be brought closer to the tangent to the cam plate 37 when the wet clutch 25 is disengaged. In other words, as the cam plate 37 rotates from the engaged position to the disengaged position, the rod 47 can be brought closer to the tangent to the cam plate 37 in the direction in which it extends.

[0181] Therefore, the rotational moment of the cam plate 37 around the rotational axis C1 can be increased. In other words, the closer the rod 47 is to the tangent to the cam plate 37 in the direction in which it extends, the greater the force that the rod 47 exerts on the cam plate 37 in the rotational direction, and the cam plate 37 can be rotated in the disengagement direction of the wet clutch 25 with a small rotational force relative to the biasing force of the disc spring 33.

[0182] As a result, the power consumption of the electric motor 43 can be reduced, and the electric motor 43 can be made smaller.

[0183] Furthermore, according to the power transmission device 4 of the hybrid vehicle of this embodiment, when the angle between the first virtual straight line L1 and the second virtual straight line L2 is at its maximum, the first connection point P1 is located closer to the rotational axis C1 of the wet clutch 25 than when the angle between the first virtual straight line L1 and the second virtual straight line L2 is at its minimum, and the first virtual straight line L1 and the second virtual straight line L2 are closer to being a straight line.

[0184] In this way, when the wet clutch 25 is disengaged, the direction in which the rod 47 extends can be brought as close as possible to the rotational axis C2. This makes the force from the cam-driven gear 46 acting on the rod 47 when the wet clutch 25 is disengaged greater than the force when the wet clutch 25 is engaged.

[0185] Therefore, when the wet clutch 25 is disengaged, the power consumption of the electric motor 43, which is opposed to the biasing force of the disc spring 33, can be reduced, while the electric motor 43 can maintain the wet clutch 25 in the disengaged state.

[0186] Furthermore, according to the power transmission device 4 of this embodiment of the hybrid vehicle, the reduction gear pair has a drive gear 12 to which power is transmitted from the motor generator 2, and a driven gear 27 which is formed to be larger in diameter than the drive gear 12 and meshes with the drive gear 12, and the cam driven gear 46 is arranged to have the same rotational axis C2 as the drive gear 12.

[0187] This allows the cam-driven gear 46 to be positioned closer to the drive gear 12, preventing an increase in the space required for the cam-driven gear 46. As a result, the power transmission device 4 can be made smaller.

[0188] Furthermore, according to the power transmission device 4 of the hybrid vehicle of this embodiment, the wet clutch 25 includes a clutch input member 26 to which power is transmitted from the internal combustion engine 1, a driven gear 27 connected to the torque converter 5 of the transmission 3 and meshing with the drive gear 12, and an input-side friction plate 30 and an output-side friction plate 31 that engage with the clutch input member 26 and the driven gear 27, and disconnect and reconnect the clutch input member 26 and the driven gear 27.

[0189] The biasing member 28 includes a pressing plate 32 and a disc spring 33 that biases the pressing plate 32 so as to press the input-side friction plate 30 and the output-side friction plate 31 against the driven gear 27 via the pressing plate 32.

[0190] The release mechanism 36 includes a release bearing 40 attached to the cam plate 37 and in contact with the pressure plate 32 in the direction of the rotational axis of the wet clutch 25, and a wave washer 29 that presses the release bearing 40 against the pressure plate 32 by biasing the thrust plate 39 to the cam plate 37.

[0191] This allows the wave washer 29 to eliminate play in the rotational axis direction of the thrust plate 39, cam plate 37, release bearing 40, and pressure plate 32, ensuring that the release bearing 40 makes secure contact with the pressure plate 32. As a result, wear of the release bearing 40 due to sliding with the pressure plate 32 can be suppressed.

[0192] While embodiments of the present invention have been disclosed, it will be apparent to those skilled in the art that modifications can be made without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims. [Explanation of Symbols]

[0193] 1. Internal combustion engine 2. Motor Generator (Rotating Electric Machine) 3. Transmission 4. Power transmission device 10 cases 12. Drive gear (drive reduction gear, reduction gear pair) 25 Wet clutch (clutch) 26 Clutch input member 27. Driven gear (driven reduction gear, reduction gear pair) 27c Cylindrical engagement part (support part, engagement part) 27d Slit (support part, engagement part) 28. Biasing member 29 Wave washer (second spring component) 30 Input side friction plate (friction member) 31 Output side friction plate (friction member) 32. Pressing plate (pressing member) 32E First claw portion (support portion, claw portion) 32F Second claw section (support section, claw section) 33 Disc spring (biasing member, first spring member) 34. Spring fixing flange (biasing member) 36. Release mechanism (release component) 37 Cam plate (drive cam plate) 37a Cam groove (ball cam section) 38. Ball (Ball cam section) 39. Thrust plate (fixed cam plate) 39a Cam groove (ball cam section) 40 Release Bearing 41 Link mechanism 43 Electric motor (actuator) 45 Cam drive gear 46 Cam-driven gear 47 Rods C1 Rotation axis (rotation axis of the clutch) C2 Rotational axis (rotational axis radially separated from the clutch's rotational axis) L1 First virtual line L2 Second virtual line P1 First connection point P2 Second connection point

Claims

1. The system comprises a clutch positioned between an internal combustion engine and a transmission, capable of disconnecting and reconnecting power transmission between the internal combustion engine and the transmission; a pair of reduction gears that transmit power between a rotating electric machine and the transmission; a release member that engages and disengages the clutch; and an actuator that operates the release member. The release member is a power transmission device for a hybrid vehicle that moves in the direction of the rotational axis of the clutch by rotation around the rotational axis of the clutch, thereby engaging and disengaging the clutch. A link mechanism having a rod is arranged between the actuator and the release member. A power transmission device for a hybrid vehicle, characterized in that the link mechanism converts the power of the actuator into rotational motion of the release member.

2. The actuator is composed of a motor having a cam drive gear, The aforementioned release member is The clutch comprises a fixed cam plate, a drive cam plate facing the fixed cam plate in the direction of the rotation center axis of the clutch, and a ball cam portion provided on the fixed cam plate and the drive cam plate, which converts the rotational motion of the drive cam plate into motion in the direction of the rotation center axis of the clutch to engage and disengage the clutch. The aforementioned link mechanism is A cam driven gear has a rotational axis radially separated from the rotational axis of the clutch and meshes with the cam drive gear, The power transmission device for a hybrid vehicle according to claim 1, characterized in that it has a rod connected to the cam driven gear and the drive cam plate, which transmits the power of the cam driven gear to the drive cam plate.

3. The clutch has a biasing member that biases the clutch so that it is in an engaged state, The release member is configured to disengage the clutch when the drive cam plate moves in the rotational axis direction of the clutch against the biasing force of the biasing member. When a first virtual line is defined as the line connecting the first connection point, which connects the cam driven gear and one end of the rod, and the rotational axis of the cam driven gear, and a second virtual line is defined as the line connecting the second connection point, which connects the drive cam plate and the other end of the rod, and the first connection point, The power transmission device for a hybrid vehicle according to claim 2, characterized in that the larger the angle formed by the first virtual line and the second virtual line, the more the drive cam plate rotates in the direction of disengaging the clutch.

4. The power transmission device for a hybrid vehicle according to claim 3, characterized in that when the angle between the first virtual straight line and the second virtual straight line is at its maximum, the first connection point is located closer to the rotational axis of the clutch than when the angle is at its minimum, and the first virtual straight line and the second virtual straight line approach a straight line.

5. The reduction gear pair comprises a drive reduction gear to which power is transmitted from the rotating electric machine, and a driven reduction gear which is formed to be larger in diameter than the drive reduction gear and meshes with the drive reduction gear. The power transmission device for a hybrid vehicle according to claim 3, characterized in that the cam driven gear is arranged to have the same rotational axis as the drive reduction gear.

6. The aforementioned clutch is A clutch input member to which power is transmitted from the internal combustion engine, A driven reduction gear connected to the transmission and meshing with the drive reduction gear, The clutch input member engages with the driven reduction gear, and the clutch input member has a friction member that disconnects the driven reduction gear, The biasing member is It comprises a pressing member and a first spring member that biases the pressing member so as to press the friction member against the driven reduction gear via the pressing member, The aforementioned release member is A release bearing is attached to the drive cam plate and contacts the pressing member in the direction of the rotation center axis of the clutch, The power transmission device for a hybrid vehicle according to claim 5, further comprising a second spring member that biases the fixed cam plate against the drive cam plate, thereby pressing the release bearing against the pressing member.

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