Power transmission system for hybrid vehicles

Abstract

To provide a power transmission system for hybrid vehicles that enables the realization of a clutch with a simple configuration and improves the work efficiency of manufacturing power transmission systems that have a clutch. [Solution] In the power transmission device 4, the pressing plate 32 has a first claw portion 32E and a second claw portion 32F that contact the cylindrical engaging portion 27c and the slit 27d of the driven gear 27, respectively. The cylindrical engaging portion 27c and the slit 27d support the pressing plate 32 on the driven gear 27 via the first claw portion 32E and the second claw portion 32F so that the pressing plate 32 can move only in the axis direction of the rotation center of the wet clutch 25.

Description

Technical Field

[0007]

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

Background Art

[0002] Conventionally, a clutch device for transmitting power from an engine to a transmission or interrupting the transmission is known (see Patent Document 1).

[0003] This clutch device includes an input gear to which engine power is transmitted, a clutch housing having a plurality of protrusions fitted into a through-hole of the input gear, a clutch center connected to the clutch housing via a friction material, a pressure plate disposed between the clutch center and the input gear and disconnecting / connecting the input gear and the clutch center via a friction material, and a plurality of cam mechanisms for moving the pressure plate in the clutch disconnecting / connecting direction.

[0004] The pressure plate is supported by the clutch center so as to be axially movable and rotates integrally with the clutch center.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the conventional clutch device, a clutch center, a pressure plate, a friction material, and a cam mechanism are provided on one axial side with respect to the input gear, and the pressure plate is attached to the clutch center.

[0007] Consequently, in order to miniaturize the clutch device, shortening the shaft length of the clutch device requires efficiently arranging the clutch center, pressure plate, friction material, and cam mechanism in the space on one side of the input gear, which may complicate the configuration of the clutch device.

[0008] Furthermore, because the pressure plate is mounted on the clutch center, it is necessary to secure space on one side of the input gear to move the pressure plate axially, which may make the configuration of the clutch device even more complex.

[0009] Therefore, there is a risk that the work efficiency of the clutch device manufacturing process will deteriorate, and it is necessary to improve the work efficiency of the manufacturing process in order to manufacture power transmission devices equipped with a clutch device.

[0010] This invention was made in view of the circumstances described above, and aims to provide a power transmission device for a hybrid vehicle that can realize a clutch with a simple configuration and improve the workability of the manufacturing process for power transmission devices having a clutch. [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 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; and a release member that moves in the direction of the rotation center axis of the clutch by rotation around the rotation center axis of the clutch to disconnect and reconnect the clutch, wherein the pair of reduction gears comprises a drive gear to which power is transmitted from the rotating electric machine and a driven gear that meshes with the drive gear and is linked to the transmission, and the clutch comprises a clutch input member to which power is transmitted from the internal combustion engine, the driven gear, a friction member that disconnects and reconnects the clutch input member and the driven gear, and a biasing member that presses the friction member against the driven gear, thereby disengaging the friction member The clutch has a pressing member that connects the clutch input member and the driven gear via a release member, the clutch input member, the friction member and the pressing member are arranged on one side of the driven gear in the direction of the rotation center axis of the clutch, the release member is arranged on the other side of the driven gear in the direction of the rotation center axis of the clutch, a plurality of through holes are formed in the driven gear, the pressing member is inserted into the through holes so as not to contact the through holes and has a receiving portion that receives an operating force from the release member in the direction of disengaging the clutch, the pressing member has a contact portion that abuts against a support portion of the driven gear, and the support portion supports the pressing member on the driven gear at the contact portion so that the pressing member is movable only in the direction of the rotation center axis of the clutch. [Effects of the Invention]

[0012] As described above, the present invention makes it possible to realize a clutch with a simple configuration and improve the workability of the manufacturing process for power transmission devices having a clutch. [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 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 5] Figure 5 is a view of the power transmission device from the internal combustion engine side with the right-side case of the power transmission device according to one embodiment of the present invention removed. [Figure 6] Figure 6 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. [Figure 7] Figure 7 is a cross-sectional view of the connection between the driven gear and the torque converter and the surrounding area of ​​a power transmission device according to one embodiment of the present invention. [Modes for carrying out the invention]

[0014] A power transmission device for a hybrid vehicle according to an embodiment of the present invention is disposed between an internal combustion engine and a transmission, and includes a clutch capable of disconnecting and connecting power transmission between the internal combustion engine and the transmission, a reduction gear pair for transmitting power between a rotary electric machine and the transmission, and a release member that moves in the direction of the rotation center axis of the clutch by rotating about the rotation center axis of the clutch to disconnect and connect the clutch. The reduction gear pair includes a driving gear to which power from the rotary electric machine is transmitted, and a driven gear that meshes with the driving gear and is interlocked with the transmission. The clutch includes a clutch input member to which power from the internal combustion engine is transmitted, the driven gear, a friction member for disconnecting and connecting the clutch input member and the driven gear, and a pressing member that is biased by a biasing member to press the friction member against the driven gear, thereby connecting the clutch input member and the driven gear via the friction member. The clutch input member, the friction member, and the pressing member are disposed on one side in the direction of the rotation center axis of the clutch with respect to the driven gear, and the release member is disposed on the other side in the direction of the rotation center axis of the clutch with respect to the driven gear. A plurality of through holes are formed in the driven gear, and the pressing member is inserted into the through holes so as not to contact the through holes, and has a receiving portion that receives an operating force in a direction to disconnect the clutch from the release member. The pressing member has a contact portion that contacts a support portion of the driven gear, and the support portion supports the pressing member on the driven gear at the contact portion so that the pressing member is movable only in the direction of the rotation center axis of the clutch.

[0015] Thereby, a power transmission device for a hybrid vehicle according to an embodiment of the present invention can realize a clutch with a simple configuration and improve the workability of the manufacturing operation of the power transmission device having the clutch.

Embodiment

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

[0017] FIGS. 1 to 7 are diagrams showing a power transmission device for a hybrid vehicle according to an embodiment of the present invention.

[0018] First, the configuration will be described. In FIGS. 1 to 7, the up-down, front-back, and left-right directions are based on the power transmission device in the state of being arranged in the hybrid vehicle. The front-back direction of the hybrid vehicle is the front-back direction, the left-right direction (vehicle width direction) of the hybrid vehicle is the left-right direction, and the up-down direction (height direction) of the hybrid vehicle is the up-down direction.

[0019] As shown in FIG. 1, the hybrid vehicle has an internal combustion engine 1, a motor generator 2, and a transmission 3. And 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, connecting 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 arranged on the internal combustion engine 1 side with respect to the power transmission device 4. The motor generator 2 is arranged behind the internal combustion engine 1 and is fixed to the cylinder block (not shown) of the internal combustion engine 1 and the power transmission device 4. The motor generator 2 transmits power to the transmission 3 via the power transmission device 4, and has a regeneration function of generating electricity by the power transmitted from the transmission 3 via the power transmission device 4.

[0023] Specifically, the motor generator 2 has a function as an electric motor that generates power by the electric power supplied from a battery (not shown) via an inverter (not shown), and a function as a generator that performs regenerative power generation by the 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 4). 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 in the direction of the rotational center relative to the clutch input member 26. The output-side friction plate 31 is attached to the outer circumference of the pressing plate 32.

[0061] In detail, the output-side friction plate 31 is fitted into a cylindrical plate holding portion 32B formed on the pressing plate 32, and the inner circumference of the output-side friction plate 31 engages with a slit hole 32a formed in the plate holding portion 32B along the rotational axis C1. The output-side friction plate 31 is rotatable integrally with the pressing plate 32 and is also movable relative to the pressing plate 32 in the rotational axis direction.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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).

[0068] 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.

[0069] As shown in Figures 2 and 4, 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.

[0070] 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.

[0071] As shown in Figure 4, the output-side friction plate 31 is attached to the cylindrical plate holder 32B so as to surround it.

[0072] The inner circumference of the output-side friction plate 31 engages with the slit hole 32a formed in the plate holding portion 32B, allowing the output-side friction plate 31 to rotate integrally with the plate holding portion 32B and to move in the axis direction of the rotation center relative to the plate holding portion 32B. As a result, the output-side friction plate 31 rotates integrally with the pressing plate 32.

[0073] 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.

[0074] The outer disc portion 27A of the driven gear 27 has multiple through holes 27b that are spaced equally apart in the circumferential direction, and the bent portion 32D is inserted through the through holes 27b. The through holes 27b are formed as elongated holes that are longer in the circumferential direction than in the radial direction (see Figure 2).

[0075] The through-hole 27b is formed to be sufficiently large relative to the bent portion 32D, is spaced apart so as not to contact the bent portion 32D, and is positioned to surround the bent portion 32D.

[0076] As shown in Figures 2 and 4, 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 the circumferential direction of the driven gear 27, and is arranged in an annular shape around the rotational axis C1. Note that the input side friction plate 30 and the output side friction plate 31 are omitted from the illustration in Figure 2.

[0077] 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 by the cylindrical engaging portion 27c so as to be coaxial with the driven gear 27.

[0078] As shown in Figure 2, the cylindrical engagement 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 positioned within the slits 27d, extending radially from the outside to the inside of the cylindrical engagement portion 27c, and is in contact with and engaged with the slits 27d.

[0079] As a result, the pressing plate 32 is positioned in the circumferential direction of the driven gear 27 by the slit 27d. The contact points of the first claw portion 32E and the second claw portion 32F that abut against the cylindrical engaging portion 27c of the driven gear constitute the contact portion.

[0080] In other words, the pressing plate 32 is movable in the axial direction but rotates integrally with the driven gear 27. The bent portion 32D is positioned in the radial and circumferential directions of the driven gear 27 by the cylindrical engaging portion 27c and the slit 27d so as not to contact the through hole 27b, and is mounted so as not to move in the radial and circumferential directions of the driven gear 27.

[0081] The bent portion 32D in this embodiment constitutes a receiving portion that receives an operating force from the release member, described later, in the direction of disengaging the clutch. The cylindrical engaging portion 27c and the slit 27d, which the first claw portion 32E and the second claw portion 32F abut against, constitute a support portion, and the first claw portion 32E and the second claw portion 32F constitute a claw portion. The cylindrical engaging portion 27c constitutes an engaging portion and a first engaging portion, and the slit 27d constitutes an engaging portion and a second engaging portion.

[0082] 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. In other words, the pressure plate 32 is pressed toward the transmission 3 by the biasing force of the disc spring 33. The disc spring 33 in this embodiment constitutes the first spring member.

[0083] 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 edge of the cylindrical portion widens beyond the inner diameter of the disc spring 33, pressing the inner end of the disc spring 33 towards the driven gear 27 from the right side. An oil seal 13D, which will be described later, is attached to the inner diameter side of this cylindrical portion.

[0084] 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.

[0085] The spring fixing flange 34 is superimposed on the outer disc portion 27A of the driven gear 27 with an O-ring 13E in between, radially inward of the disc spring 33 (see Figure 7), and is fastened and fixed to the inner disc portion 27B from the internal combustion engine 1 side by bolts 9E, thereby ensuring pressure on the disc spring 33 and a liquid-tight seal between the spring fixing flange 34 and the driven gear 27.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] As shown in Figures 1 and 4, 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.

[0092] 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).

[0093] A bearing 11D, described later, is positioned on the inner diameter side of the cylindrical portion 35B of the bearing fixing flange 35, and the bearing 11D is held in the left case portion 10B by the bearing fixing flange 35. More specifically, the outer ring 11b of the bearing 11D is held between the bearing fixing flange 35 and the left case portion 10B in the direction of the rotational axis C1.

[0094] 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.

[0095] 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).

[0096] 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.

[0097] 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).

[0098] 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.

[0099] 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.

[0100] The cam plate 37 rotates within a certain range around its rotational axis by the link mechanism 41.

[0101] As shown in Figure 6, 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.

[0102] 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.

[0103] 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).

[0104] 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 whose depth in the direction of the rotational axis increases from one end to the other end in the rotation direction of the internal combustion engine 1.

[0105] 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.

[0106] The cam grooves 37a and 39a house balls 38, and the balls 38 are capable of rolling along the cam grooves 37a and 39a.

[0107] As shown in Figure 4, 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.

[0108] As shown in Figure 4, the release bearing 40 has an outer ring 40A fixed to the cam plate 37 and moves in the direction of the rotational axis as a whole with the cam plate 37.

[0109] 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, transmitting 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. 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).

[0110] 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.

[0111] As shown in Figure 4, 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 the play in the release mechanism 36. In this embodiment, the wave washer 29 constitutes a second spring member.

[0112] The electric motor 43 that operates the release mechanism 36 is attached to the left side case portion 10B by bolts (not shown). As shown in Figure 3, a cam drive gear 45 is attached to the electric motor 43, and the cam drive gear 45 is rotated by the electric motor 43.

[0113] The link mechanism 41 is positioned between the electric motor 43, which acts as an actuator, and the release mechanism 36.

[0114] As shown in Figures 3 and 5, 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.

[0115] As shown in Figure 1, the rotating member 46A is rotatably mounted on the bearing support portion 10c via a metal bearing 44. 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.

[0116] 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.

[0117] As shown in Figure 5, 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.

[0118] 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.

[0119] 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).

[0120] 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 the other end.

[0121] 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.

[0122] 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.

[0123] 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.

[0124] Figure 5 shows the position of the cam driven plate 46B when the wet clutch 25 is disengaged. The electric motor 43 drives the cam drive gear 45, causing the cam driven plate 46B to move in the R1 direction (the direction in which the clutch is disengaged) around the rotational axis C2. As a result, the connection point P1 between the cam driven plate 46B and the rod 47 moves from a position away from the cam plate 37 toward the cam plate 37, and the cam plate 37 is pushed by the rod 47 and rotates in the R1 direction (the direction in which the clutch is disengaged) around the rotational axis C1.

[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 between the internal combustion engine 1 and the driven gear 27 is interrupted.

[0130] A stopper claw 46b is provided at one end of the cam-driven plate 46B in the circumferential direction, 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-side 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 5, 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 rotation center 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 circumferential end of the cam-driven plate 46B, 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. This restricts the rotation of the cam-driven gear 46 in the direction R2 in which the wet clutch 25 is further engaged from the state in which the wet clutch 25 is engaged.

[0138] 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.

[0139] In other words, the circumferential lengths of the cam grooves 37a and 39a are made long so that the ball 38 does not simultaneously collide with the wall portion of the circumferential end of the cam groove 37a and the wall portion of the circumferential end of the cam groove 39a, from the state in which the stopper claw 46b is in contact with the contact portion 10g to the state in which the stopper claw 46c is in contact with the contact portion 10h.

[0140] 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.

[0141] 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°.

[0142] 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.

[0143] 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.

[0144] As shown in Figure 7, the outer circumference of the inner disc portion 27B of the driven gear 27 constitutes a bearing mounting portion 27e, and the inner ring 11a of the bearing 11D is attached to the bearing mounting portion 27e.

[0145] A bearing fixing flange 48 is press-fitted onto the left side surface of the inner disc portion 27B. The bearing fixing flange 48 is a heat-treated, high-hardness disc-shaped component. The basic disc portion has a central hole 48c in its center into which the rotating shaft 5a of the torque converter 5 is inserted and fitted. Around this central hole 48c are tool insertion holes into which a tool for tightening bolts 9B that fasten the damper input member 22 to the crankshaft 1A is inserted, and mounting holes through which bolts 9C pass and are fastened to the inner disc portion 27B together with the drive plate 5A of the torque converter 5 using bolts 9C.

[0146] The outer edge of the basic disc portion extends cylindrically toward the driven gear 27, forming a cylindrical portion 48d. The inner disc portion 27B of the driven gear 27 is press-fitted into the inner diameter of the cylindrical portion 48d for positioning, its outer diameter becomes the sliding surface of the oil seal 13B (described later), and the end face on the driven gear 27 side abuts against the inner ring 11a of the bearing 11D. In other words, the left end of the inner ring 11a of the bearing 11D abuts against the cylindrical portion 48d, preventing the bearing 11D from coming out of the inner disc portion 27B.

[0147] Furthermore, the inner ring 11a of 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 flange 48 and the outer disc portion 27A.

[0148] 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.

[0149] As shown in Figure 7, an oil seal contact portion 48a is provided at the outer end of the bearing fixing flange 48, and the oil seal 13B is in contact with the oil seal contact portion 48a. In this embodiment, the oil seal contact portion 48a constitutes the seal member contact portion.

[0150] The edge of the central hole 48c of the bearing fixing flange 48 has a cylindrical projection 48b that extends toward the transmission 3. The rotating shaft 5a of the torque converter 5 is inserted into the inner diameter of the cylindrical projection 48b and fitted into it for positioning, and the central hole 48c of the drive plate 5A is fitted into its outer diameter to position the drive plate 5A.

[0151] The cylindrical projection 48b is located radially inward from the bearing 11D and protrudes toward the transmission 3 from the basic disc portion of the bearing fixing flange 48.

[0152] In other words, the inner end of the cylindrical projection 48b radially positions the outer end of the rotating shaft 5a of the front cover of the torque converter 5, and the outer end of the cylindrical projection 48b radially positions the inner end of the drive plate 5A. The drive plate 5A is then placed on top of the basic disc portion and fastened to the inner disc portion 27B with bolts 9C.

[0153] The inner disc portion 27B has a recess 27f formed along its axis, and the tip of the rotating shaft 5a, positioned on the cylindrical projection 48b, is positioned to pass through the bearing fixing flange 48 and enter the recess 27f. The diameter of the hole in the recess 27f is larger than the inner diameter of the cylindrical projection 48b, and the cylindrical projection 48b is positioned on the transmission 3 side of the opening of the recess 27f to reduce its diameter. In this embodiment, the torque converter 5 constitutes a rotating member, and the cylindrical projection 48b constitutes a positioning part.

[0154] In other words, the bearing fixing flange 48, which has an oil seal contact portion 48a that the oil seal 13B abuts against and a cylindrical projection portion 48b that positions the torque converter 5, is made of a separate component from the driven gear 27. The bearing fixing flange 48 in this embodiment constitutes a flange member.

[0155] The bearing fixing flange 48, which is smaller than the driven gear 27, is carburized and hardened, giving the bearing fixing flange 48 high hardness and wear resistance.

[0156] Since the bearing fixing flange 48 rotates integrally with the driven gear 27 and slides against the oil seal 13B, the wear resistance of the oil seal contact portion 48a can be improved.

[0157] 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.

[0158] 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.

[0159] 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.

[0160] On the other hand, in this embodiment, the driven gear 27 is subjected to high-frequency induction hardening of the teeth 27a and the cylindrical engaging portion 27c after machining, which improves the wear resistance of the teeth 27a and the cylindrical engaging portion 27c.

[0161] Specifically, the teeth 27a mesh with the drive gear 12 and are in sliding contact with the drive gear 12, so the wear resistance of the teeth 27a can be improved by applying high-frequency induction hardening to the teeth 27a.

[0162] On the other hand, the radial inner end of the first claw portion 32E of the pressing plate 32 abuts against the cylindrical engaging portion 27c, and when the pressing plate 32 moves in the axis direction of the rotation center during engagement and disengagement of the wet clutch 25, the first claw portion 32E slides against the cylindrical engaging portion 27c. For this reason, the wear resistance of the cylindrical engaging portion 27c can be improved by applying high-frequency induction hardening to the cylindrical engaging portion 27c.

[0163] Furthermore, the second claw portion 32F of the pressing plate 32 is positioned in contact with the slit 27d of the cylindrical engaging portion 27c, and when the pressing plate 32 moves in the axis direction of the rotation center during engagement and disengagement of the wet clutch 25, the second claw portion 32F slides against the cylindrical engaging portion 27c.

[0164] Therefore, by applying high-frequency induction hardening to the cylindrical engagement portion 27c, the wear resistance of the cylindrical engagement portion 27c (the edge facing the slit 27d) can be improved. Durability is improved by heat-treating only the tooth portion 27a and the cylindrical engagement portion 27c, and furthermore, since the bearing fixing flange 48, which is a separate heat-treated component, is attached to the driven gear 27, it is not necessary to heat-treat the entire driven gear 27, and distortion due to heat treatment of the driven gear 27 can be minimized.

[0165] 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.

[0166] 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.

[0167] 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.

[0168] 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.

[0169] 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.

[0170] 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.

[0171] 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.

[0172] 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. In other words, the power from the drive wheels is transmitted to the transmission 3 via the left and right drive shafts and differential. The 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.

[0173] 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.

[0174] 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 positioned 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, and a release mechanism 36 that moves in the direction of the rotation center axis of the wet clutch 25 by rotation around the rotation center axis C1 of the wet clutch 25, thereby disconnecting and reconnecting the wet clutch 25.

[0175] Power from the motor generator 2 is transmitted to the drive gear 12, and the driven gear 27 meshes with the drive gear 12 and also works in conjunction with the torque converter 5 of the transmission 3.

[0176] 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, an input-side friction plate 30 and an output-side friction plate 31 that engage and disengage the clutch input member 26 and the driven gear 27, and a pressing plate 32 that is biased by a biasing member 28 and presses the input-side friction plate 30 and the output-side friction plate 31 against the driven gear 27, thereby connecting the clutch input member 26 and the driven gear 27 via the input-side friction plate 30 and the output-side friction plate 31.

[0177] 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).

[0178] The driven gear 27 has multiple through holes 27b formed therein, and the pressing plate 32 is inserted into the through holes 27b so as not to contact the through holes 27b and has a bent portion 32D that receives an operating force from the release mechanism 36 in the direction of disengaging the wet clutch 25.

[0179] The pressing plate 32 has a first claw portion 32E and a second claw portion 32F that contact the cylindrical engagement portion 27c and the slit 27d of the driven gear 27, respectively. The cylindrical engagement portion 27c and the slit 27d support the pressing plate 32 on the driven gear 27 with the first claw portion 32E and the second claw portion 32F so that the pressing plate 32 can move only in the axis direction of the rotation center of the wet clutch 25.

[0180] In this way, the clutch input member 26, input-side friction plate 30, output-side friction plate 31, and pressing plate 32 are positioned to the left of the driven gear 27 in the direction of the rotational axis, the pressing plate 32 is supported by the driven gear 27, and the release mechanism 36 can be positioned to the right of the driven gear 27.

[0181] In other words, the pressing plate 32 can receive an operating force from the release mechanism 36 in the direction of disengaging the wet clutch 25 through the through hole 27b of the driven gear 27, so the clutch input member 26, input-side friction plate 30, output-side friction plate 31, and pressing plate 32, and the release mechanism 36 can be arranged on the left and right sides relative to the driven gear 27.

[0182] Therefore, even if the dimensions of the power transmission device 4 in the direction of the rotation axis are shortened, the wet clutch 25 and the release mechanism 36 can be easily assembled inside the case 10, resulting in a simple wet clutch 25 configuration. As a result, the workability of the manufacturing process for the power transmission device 4 can be improved.

[0183] Furthermore, since the pressing plate 32 is positioned on the driven gear 27 by the first claw portion 32E, the second claw portion 32F, the cylindrical engaging portion 27c, and the slit 27d, there is no need to position it using the bent portion 32D and the through hole 27b. This eliminates the need to finish the dimensional accuracy of the bent portion 32D and the through hole 27b with high precision, thereby improving productivity.

[0184] In other words, since the pressing plate 32 is supported on the driven gear 27 in such a way that the bent portion 32D does not come into contact with the through hole 27b, there is no need to increase the machining accuracy of the through hole 27b or the bent portion 32D. Therefore, the manufacturing of the driven gear 27 can be made easier.

[0185] Furthermore, according to the power transmission device 4 of this embodiment of the hybrid vehicle, the first claw portion 32E and the second claw portion 32F extend from the outer diameter side to the inner diameter side of the pressing plate 32.

[0186] In addition, the cylindrical engaging portion 27c protrudes cylindrically from the side of the driven gear 27 facing the internal combustion engine 1, with the rotational axis C1 as its central axis. The cylindrical engaging portion 27c and the slit 27d engage with the first claw portion 32E and the second claw portion 32F such that the first claw portion 32E and the second claw portion 32F are movable only in the direction of the rotational axis.

[0187] As a result, the pressing plate 32 can be supported by the driven gear 27 through the first claw portion 32E, the second claw portion 32F, the cylindrical engaging portion 27c, and the slit 27d, and the pressing plate 32 can be supported by the driven gear 27 with a simple configuration.

[0188] Furthermore, according to the power transmission device 4 of the hybrid vehicle of this embodiment, the pressing plate 32 has a first claw portion 32E and a second claw portion 32F provided spaced apart from the first claw portion 32E in the circumferential direction of the pressing plate 32.

[0189] The driven gear 27 has a cylindrical engaging portion 27c provided on the inner diameter side of the driven gear 27 relative to the first claw portion 32E, which abuts against the radially inner end of the first claw portion 32E to position the pressing plate 32 radially relative to the driven gear 27, and a slit 27d which engages with the second claw portion 32F in the circumferential direction to position the pressing plate 32 circumferentially relative to the driven gear 27.

[0190] In addition, the pressing plate 32 is movable in the direction of the rotation center by the first claw portion 32E moving along the cylindrical engagement portion 27c in the direction of the rotation center, and the second claw portion 32F moving along the slit 27d in the direction of the rotation center.

[0191] This allows the pressing plate 32 to be positioned radially (axis position of the central axis) and circumferentially on the driven gear 27, and the bent portion 32D can be moved in the rotational axis direction without contacting the through hole 27b.

[0192] Therefore, there is no need to increase the machining accuracy of the through hole 27b, and the workability of the manufacturing process for the driven gear 27 can be improved more effectively.

[0193] Furthermore, the power transmission device 4 of the hybrid vehicle of this embodiment includes a case 10 that houses a wet clutch 25, a drive gear 12, a driven gear 27, an input-side friction plate 30, an output-side friction plate 31, and a release mechanism 36; a bearing 11D that rotatably supports the driven gear 27 in the case 10; and an oil seal 13D provided outward in the axial direction of the rotation center of the bearing 11D and between the driven gear 27 and the left-side case portion 10B.

[0194] The driven gear 27 has a bearing mounting portion 27e to which the bearing 11D is attached, and a bearing fixing flange 48, which is made of a separate component from the driven gear 27, is attached to the driven gear 27.

[0195] The bearing fixing flange 48 is provided radially inward from the bearing 11D and has a cylindrical projection 48b that positions the rotating shaft 5a of the front cover of the torque converter 5, to which power is transmitted from the driven gear 27, and the drive plate 5A; a cylindrical portion 48d that engages with the bearing 11D to prevent the bearing 11D from coming out of the inner disc portion 27B; and an oil seal contact portion 48a to which the oil seal 13D abuts.

[0196] This makes heat treatment of the driven gear 27 easier and eliminates the need to improve the machining accuracy of the driven gear 27. By attaching a bearing fixing flange 48, which is smaller and more precisely finished than the driven gear 27, to the driven gear 27, the rotation axis 5a of the front cover and the rotation center axis C1 of the drive plate 5A can be positioned, thereby more effectively improving the workability of the manufacturing process of the driven gear 27.

[0197] Furthermore, the bearing fixing flange 48 has a cylindrical portion 48d formed on its outer edge. The inner disc portion 27B of the driven gear 27 is press-fitted into the inner diameter portion of the cylindrical portion 48d for positioning, so that the oil seal contact portion 48a formed on its outer diameter can be positioned on the rotational center axis C1 of the oil seal 13D.

[0198] This prevents the oil seal 13D from shifting radially with respect to the rotational axis C1, thereby preventing a decrease in the sealing performance of the oil seal 13D.

[0199] If we were to form the oil seal contact portion 48a on the driven gear 27 without using the bearing fixing flange 48, it would be necessary to perform heat treatment such as carburizing and quenching on the entire driven gear 27 after machining, which would cause distortion and deformation of the driven gear 27.

[0200] Furthermore, the pressing plate 32 receives an operating force from the release mechanism 36 in the direction of disengaging the wet clutch 25 through the through hole 27b of the driven gear 27. Let's consider the case where a release pin is provided on the driven gear 27 instead of the bent portion 32D.

[0201] In this case, multiple release pins will be provided on the driven gear 27, and multiple pin holes will be formed in the driven gear 27 through which the release pins are slidably inserted. These multiple pin holes need to be finished with high precision not only in terms of positional accuracy but also in terms of axis tilt and parallelism in order to ensure operational stability.

[0202] However, when the driven gear 27 is heat-treated, distortion and deformation occur in the driven gear 27, so the pin holes need to be precisely post-machined after the heat treatment. As a result, the number of machining steps for the driven gear 27 increases, the manufacturing time for the driven gear 27 lengthens, and the work efficiency of the manufacturing process for the driven gear 27 deteriorates.

[0203] In this embodiment, the driven gear 27 is not subjected to overall heat treatment that would cause distortion or deformation. Instead, the teeth 27a and cylindrical engagement portion 27c, which are the sliding parts, are subjected to high-frequency induction hardening to improve wear resistance. A through hole 27b is formed in the driven gear 27 into which the bent portion 32D of the pressing plate 32 is inserted, instead of a release pin.

[0204] The pressing plate 32 is supported such that it cannot move radially or circumferentially relative to the driven gear 27, and the bent portion 32D does not come into contact with the through hole 27b.

[0205] As a result, the driven gear 27 can be manufactured without heat treatment or post-processing to correct the distortion caused by the heat treatment, thereby improving the workability of the manufacturing process for the driven gear 27.

[0206] 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]

[0207] 1. Internal combustion engine 2. Motor Generator (Rotating Electric Machine) 3. Transmission 4. Power transmission device 5. Torque converter (rotating component) 11D bearing 12. Drive gear (reducing gear pair) 13D Oil seal (sealing component) 25 Wet clutch (clutch) 26 Clutch input member 27. Driven gear (paired with reduction gear) 27b Through hole 27c Cylindrical engaging portion (support portion, engaging portion, first engaging portion) 27d Slit (support part, engaging part, second engaging part) 27e Bearing mounting section 28. Biasing member 30 Input side friction plate (friction member) 31 Output side friction plate (friction member) 32. Pressing plate (pressing member) 32D Folding section (receiving section) 32E First claw portion (contact portion) 32F Second claw portion (contact portion) 36. Release mechanism (release component) 48 Bearing fixing flange (flange member) 48a Oil seal contact area (seal member contact area) 48b Cylindrical projection (positioning part) 48d Cylindrical section (retaining section) C1 Rotation axis (rotation axis of the clutch)

Claims

1. A power transmission system for a hybrid vehicle comprising: 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; and a release member that moves in the direction of the rotation center axis of the clutch by rotation around the rotation center axis of the clutch, thereby disconnecting and reconnecting the clutch; The aforementioned reduction gear pair is, It has a drive gear to which power from the rotating electric machine is transmitted, and a driven gear that meshes with the drive gear and is linked to the transmission, The aforementioned clutch is A clutch input member to which power is transmitted from the internal combustion engine, The driven gear and, A friction member that disconnects the clutch input member and the driven gear, The device includes a pressing member that, when biased by a biasing member, presses the friction member against the driven gear, thereby connecting the clutch input member and the driven gear via the friction member, The clutch input member, the friction member, and the pressing member are arranged on one side of the rotational axis direction of the clutch relative to the driven gear, and the release member is arranged on the other side of the rotational axis direction of the clutch relative to the driven gear. Multiple through holes are formed in the driven gear, The pressing member is inserted into the through hole so as not to contact the through hole, and has a receiving portion that receives an operating force from the release member in the direction of disengaging the clutch. The pressing member has a contact portion that contacts the support portion of the driven gear, The power transmission device for a hybrid vehicle is characterized in that the support portion supports the pressing member on the driven gear at the contact portion such that the pressing member is movable only in the axis direction of the rotation center of the clutch.

2. The aforementioned contact portion is, The pressing member is provided with a claw portion that extends from the outer diameter side to the inner diameter side of the pressing member, The power transmission device for a hybrid vehicle according to claim 1, characterized in that the support portion has an engaging portion that engages with the claw portion such that the claw portion is movable only in the axis direction of the rotation center of the clutch.

3. The claw portion comprises a first claw portion and a second claw portion provided spaced apart from the first claw portion in the circumferential direction of the pressing member. The aforementioned engaging portion is A first engaging portion is provided on the inner diameter side of the driven gear relative to the first claw portion, and the radially inner end of the first claw portion abuts against it, thereby positioning the pressing member radially relative to the driven gear; It has a second engaging portion that engages with the second claw portion in the circumferential direction and positions the pressing member in the circumferential direction relative to the driven gear, The power transmission device for a hybrid vehicle according to claim 2, characterized in that the pressing member is movable in the direction of the rotation center by the first claw portion moving along the first engagement portion in the direction of the rotation center, and the second claw portion moving along the second engagement portion in the direction of the rotation center.

4. A case housing the clutch, the reduction gear pair, the friction member, and the release member, A bearing that rotatably supports the driven gear in the case, The bearing has a sealing member provided outward in the axial direction of the rotation center of the bearing, and is provided between the driven gear and the case. A flange member, which is a separate component from the driven gear, is attached to the driven gear. The flange member is A positioning unit provided radially inward from the bearing, which positions the rotating member of the transmission to which power is transmitted from the driven gear, A retaining portion that engages with the bearing and prevents the bearing from coming out of the driven gear, The power transmission device for a hybrid vehicle according to any one of claims 1 to 3, characterized in that it has a seal member contact portion that the seal member contacts.

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