Power transmission system for hybrid vehicles

Abstract

To provide a power transmission device for a hybrid vehicle that can supply lubricating oil to the meshing parts without using an oil guide, thereby simplifying the lubrication structure and achieving miniaturization. [Solution] In the power transmission device 4 of the hybrid vehicle, the case 10 has a vertical wall 10C facing the driven gear 27 in the direction of the rotational axis axis, and the vertical wall 10C faces the teeth 27a of the driven gear 27 in the direction of the rotational axis axis and has a first annular wall surface 10f extending in the rotational direction of the driven gear 27. The gap between the first annular wall surface 10f and the driven gear 27 has the smallest gap S1 between the lower part of the driven gear 27 and the meshing portion 15, and the gap S1 constitutes a first lubricating oil passage 51 that supplies lubricating oil scraped up by the driven gear 27 to the meshing portion 15.

Description

Technical Field

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

Background Art

[0002] Conventionally, a lubricating oil supply device for supplying lubricating oil to the meshing portion of a large-diameter gear and a small-diameter gear is known (see Patent Document 1).

[0003] This lubricating oil supply device accommodates a counter drive gear, a counter driven gear, a drive pinion gear, an MG2 reduction gear, and a differential ring gear in the case in sequence, and also accommodates an oil reservoir portion and a passage member.

[0004] The passage member has a first guide passage for guiding the lubricating oil scraped up by the large-diameter differential ring gear, and a second guide passage for guiding the lubricating oil extruded from the meshing portion of the drive pinion gear having a smaller diameter than the differential ring gear and the differential ring gear.

[0005] And the lubricating oil supply device can scrape up the lubricating oil guided from the first guide passage and the second guide passage by the rotation of the MG2 reduction gear and supply it to the oil receiving portion.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, the lubrication oil supply device described in Patent Document 1 supplies oil to the meshing portion of the drive pinion gear and the differential ring gear using a first guide passage that corresponds to an oil guide. As a result, the lubrication structure becomes more complex due to the placement of the first guide passage, and the space required for the first guide passage may lead to a larger lubrication oil supply device.

[0008] 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 supply lubricating oil to the meshing parts without using an oil guide, and can be miniaturized while simplifying the lubrication structure. [Means for solving the problem]

[0009] 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 the transmission; a release member that moves in the direction of the rotation center of the clutch by rotation around the rotation center axis of the clutch to disconnect and reconnect the clutch; and a case housing the clutch, the pair of reduction gears, and the release member. The pair of reduction gears comprises 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 meshing portion of the drive gear and the driven gear is positioned forward when the driven gear rotates. A power transmission device for a hybrid vehicle, wherein the teeth of the driven gear are located above the rotational axis of the driven gear in the direction of movement from bottom to top, the case has a vertical wall facing the driven gear in the rotational axis direction of the driven gear, the vertical wall has a first annular wall surface that faces the teeth of the driven gear in the rotational axis direction of the driven gear and extends in the rotational direction of the driven gear, the gap between the first annular wall surface and the driven gear is smallest between the lower part of the driven gear and the meshing portion, and the gap constitutes a first lubrication passage that supplies lubricating oil scraped up by the driven gear to the meshing portion. [Effects of the Invention]

[0010] As described above, according to the present invention, lubricating oil can be supplied to the meshing parts without using an oil guide, and the power transmission device can be miniaturized while simplifying the lubrication structure. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a cross-sectional view of a power transmission device for a hybrid vehicle, arranged between an internal combustion engine and a transmission, according to one embodiment of the present invention. [Figure 2] Figure 2 is a cross-sectional view of a power transmission device for a hybrid vehicle according to one embodiment of the present invention, showing the left case portion and bearing fixing flange cut in the direction of II-II in Figure 3. [Figure 3] Figure 3 is a right side view of the left case portion of a power transmission device for a hybrid vehicle according to one embodiment of the present invention. [Figure 4] Figure 4 is a perspective view of the left case portion of the power transmission device of a hybrid vehicle according to one embodiment of the present invention. [Figure 5] Figure 5 is a perspective view of the left case portion and bearing fixing flange of the power transmission device of a hybrid vehicle according to one embodiment of the present invention. [Figure 6] Figure 6 shows the gap between the vertical wall of the left case portion and the driven gear of a power transmission device for a hybrid vehicle according to one embodiment of the present invention, and is a diagram of the left case portion of Figure 3 cut along line VI-VI. [Figure 7] Figure 7 shows the inclined surface of the outer peripheral wall of the left case portion of the power transmission device of a hybrid vehicle according to one embodiment of the present invention, and is a view obtained by cutting the left case portion of Figure 3 along line VII-VII. [Figure 8] Figure 8 shows a slit in the bearing support portion of the left case portion that supports the drive gear of the power transmission device of a hybrid vehicle according to one embodiment of the present invention, and is a diagram obtained by cutting the left case portion of Figure 3 along line VIII-VIII. [Figure 9] Figure 9 shows the area around the slit in the bearing support portion of the left case portion that supports the drive gear of the power transmission device of a hybrid vehicle according to one embodiment of the present invention, and is a view obtained by cutting the left case portion of Figure 3 along line IX-IX. [Figure 10] Figure 10 shows the area around the slit in the bearing support portion of the right case portion that supports the drive gear of the power transmission device of a hybrid vehicle according to one embodiment of the present invention, and corresponds to the cross-section of the right case portion when the left case portion in Figure 3 is cut along XX. [Modes for carrying out the invention]

[0012] A power transmission device for a hybrid vehicle according to one embodiment of the present invention is arranged between an internal combustion engine and a transmission and comprises a clutch 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 moves in the axial direction of the rotation center of the clutch by rotation around the rotation center axis of the clutch to disconnect and reconnect the clutch, and a case that houses the clutch, the pair of reduction gears and the release member, wherein the pair of reduction gears comprises 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, and the drive gear and the driven gear The power transmission device for a hybrid vehicle is such that the meshing portion is located above the rotational axis of the driven gear in the direction in which the teeth of the driven gear move from bottom to top when the driven gear rotates, and the case has a vertical wall facing the driven gear in the rotational axis direction of the driven gear, the vertical wall has a first annular wall surface that faces the teeth of the driven gear in the rotational axis direction of the driven gear and extends in the rotational direction of the driven gear, the gap between the first annular wall surface and the driven gear is formed to be smallest from the bottom of the driven gear to the meshing portion, and the gap constitutes a first lubricating oil passage that supplies lubricating oil scraped up by the driven gear to the meshing portion.

[0013] As a result, the power transmission device for a hybrid vehicle according to one embodiment of the present invention can supply lubricating oil to the meshing parts without using an oil guide, thereby simplifying the lubrication structure and enabling miniaturization of the power transmission device. [Examples]

[0014] Hereinafter, a power transmission device for a hybrid vehicle according to one embodiment of the present invention will be described with reference to the drawings.

[0015] Figures 1 to 10 are diagrams showing a power transmission device of a hybrid vehicle according to an embodiment of the present invention.

[0016] First, the configuration will be described. In FIGS. 1 to 10, the vertical, front-back, and left-right directions are based on the power transmission device in the state 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 vertical direction (height direction) of the hybrid vehicle is the vertical direction.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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).

[0023] 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.

[0024] 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.

[0025] 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).

[0026] 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.

[0027] 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).

[0028] The transmission mechanism consists of a continuously variable transmission (CVT), for example. However, the transmission mechanism is not limited to CVTs.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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 (see Figures 9 and 10).

[0035] 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.

[0036] An oil seal 13A is provided between the opening 10e and the drive shaft 12A, and the space between the opening 10e and the motor shaft 2A 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 teeth 12a of 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. In other words, the rotational axis C1 is also the rotational axis of the driven gear 27.

[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] The drive gear 12 and the driven gear 27 are made up of helical gears in which the helix angles of the teeth 12a and teeth 27a are the same, and the helix directions are opposite.

[0058] Lubricating oil is stored at the bottom of case 10, and the twisting direction of teeth 12a and 27a is formed to direct the lubricating oil toward the vertical wall 10C of the left case portion 10B (see Figure 3) when the drive gear 12 and driven gear 27 rotate.

[0059] In other words, the teeth 12a and 27a are inclined with respect to the rotational axes C1 and C2, and are formed so that, in the direction of rotation when the vehicle is moving forward, the meshing of the teeth 12a and 27a begins on the right case portion 10A side and ends on the left case portion 10B side.

[0060] As shown in Figure 3, the meshing portion 15 between the teeth 12a of the drive gear 12 and the teeth 27a of the driven gear 27 is located above the rotational axis C1 of the driven gear 27 in the direction in which the teeth 27a of the driven gear 27 move from bottom to top when the driven gear 27 rotates (clockwise direction R shown in Figure 3). In this embodiment, the drive gear 12 and the driven gear 27 constitute a pair of reduction gears.

[0061] In this embodiment, the drive gear 12 is positioned such 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. The drive gear 12 is positioned such that its rotational axis C2 is located above its rotational axis C1.

[0062] 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 2). In this embodiment, the input-side friction plate 30 and the output-side friction plate 31 constitute a friction member.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] The torque converter 5 is capable of transmitting power to the forward / reverse switching mechanism. 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.

[0069] 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).

[0070] The biasing member 28 includes an annular pressing plate 32, a disc spring 33, and an annular spring fixing flange 34 (see Figure 2). In this embodiment, the pressing plate 32 constitutes the pressing member.

[0071] As shown in Figure 2, 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.

[0072] The pressing plate 32 extends radially inward from the bent portion 32C and is then bent toward the driven gear, having a plurality of bent portions 32D that are spaced apart in the circumferential direction (see Figure 8).

[0073] As shown in Figure 2, the output-side friction plate 31 is mounted on 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.

[0074] 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.

[0075] As shown in Figure 8, 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.

[0076] The through-hole 27b is formed as an elongated hole that is longer in the circumferential direction than in the radial direction, and the through-hole 27b surrounds the bent portion 32D so as not to contact the bent portion 32D.

[0077] 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. The outer end contacts the pressure plate 32, biasing it 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.

[0078] 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.

[0079] 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.

[0080] 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, and is fastened and fixed to the inner disc portion 27B from the internal combustion engine 1 side by bolts 9E.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] As shown in Figures 1 and 2, 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.

[0087] The bearing fixing flange 35 has an annular portion 35A (see Figure 5) that abuts against the inner wall surface of the left case portion 10B, and a cylindrical portion 35B (see Figure 5) 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).

[0088] The cylindrical portion 35B is provided at the radially inner end of the annular portion 35A, protruding from the annular portion 35A toward the driven gear 27, and supporting the bearing 11D radially inward.

[0089] In detail, the bearing 11D is held in the left case portion 10B by the bearing fixing flange 35, and the outer ring 11b of the bearing 11D is sandwiched and held between the bearing fixing flange 35 and the left case portion 10B in the direction of the rotational axis C1. The cylindrical portion 35B in this embodiment constitutes the first bearing support portion.

[0090] 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.

[0091] 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).

[0092] 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.

[0093] The release mechanism 36 includes an annular cam plate 37, a ball 38, a thrust plate 39, and a release bearing 40.

[0094] 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.

[0095] 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.

[0096] The cam plate 37 rotates within a certain range around the rotational axis by the annular plate 41.

[0097] 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.

[0098] 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.

[0099] 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).

[0100] 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.

[0101] 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] The thrust plate 39 is provided so as to be immobile and movable in the axis direction of rotation by engaging in the rotational direction with a pin (not shown) fixed to the bearing fixing flange 35.

[0104] As shown in Figures 1 and 2, the release bearing 40 is located radially outward from the cylindrical portion 35B and is positioned between the annular portion 35A and the driven gear 27 in the direction of the rotational axis.

[0105] The release bearing 40 has an outer ring fixed to the cam plate 37 and moves in the direction of the rotational axis as a unit with the cam plate 37.

[0106] The release bearing 40 has an inner ring 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.

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

[0108] As shown in Figures 1 and 9, the annular plate 41 is rotatably mounted on the bearing support portion 10c via a metal bearing 42. Power is transmitted to the annular plate 41 from a drive motor (not shown), and the annular plate 41 rotates within a certain range by the drive motor.

[0109] The annular plate 41 is connected to the cam plate 37 via a power transmission member (not shown). When the annular plate 41 is rotated by the drive motor, the annular plate 41 rotates the cam plate 37 via the power transmission member.

[0110] When the cam plate 37 rotates in one direction (clutch disengagement direction) around the rotational axis C1 by the power transmission member, the cam grooves 37a and 39a move relative to the ball 38, and the ball 38 moves from the position of the deeply inclined surface of the cam grooves 37a and 39a to the position of the shallowly inclined surface.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] On the other hand, when the cam plate 37 is rotated in the opposite direction (clutch engagement direction) around the rotational axis C1 by the power transmission member, the cam grooves 37a and 39a move relative to the ball 38, and the ball 38 moves from the position of the shallow inclined surface of the cam grooves 37a and 39a to the position of the deep inclined surface.

[0116] As a result, the gap between the cam plate 37 and the thrust plate 39 in the direction of the rotational center axis becomes smaller, 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.

[0117] 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.

[0118] 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.

[0119] 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.

[0120] 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.

[0121] 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, and the driven gear 27 is rotatably supported by the bearing fixing flange 35 (left side case portion 10B) via the bearing 11D.

[0122] 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.

[0123] 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 flange 48 and the outer disc portion 27A.

[0124] 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.

[0125] A cylindrical projection 48a is formed on the bearing fixing flange 48. The cylindrical projection 48a is located radially inward from the bearing 11D and protrudes from the bearing fixing flange 48 toward the internal combustion engine 1.

[0126] The inner end of the cylindrical projection 48a 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 48a radially positions the inner end of the drive plate 5A.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] As shown in Figures 1 and 3, the left case portion 10B has a vertical wall 10C and an outer peripheral wall 10D. The vertical wall 10C is located on the transmission 3 side relative to the driven gear 27 and faces the driven gear 27 in the direction of the rotational axis, with the release mechanism 36 in between.

[0131] The outer peripheral wall 10D protrudes from the radial outer periphery of the vertical wall 10C toward the internal combustion engine 1, is positioned radially outward of the drive gear 12 and the driven gear 27, and covers the drive gear 12 and the driven gear 27 from the outside.

[0132] As shown in Figures 3 and 4, the vertical wall 10C has an annular first annular wall surface 10f. The first annular wall surface 10f faces the teeth 27a of the driven gear 27 in the direction of the rotational axis, extends radially, and extends in the rotational direction of the driven gear 27.

[0133] The gap S (see Figure 6) between the first annular wall surface 10f and the driven gear 27 is formed such that the gap S1 between the lower part of the driven gear 27 and the meshing portion 15 is smaller than the gap S2 excluding the gap between the lower part of the driven gear 27 and the meshing portion 15.

[0134] In other words, the position of the inner surface of the first annular wall 10f in the direction of the rotational axis C1 is formed to be a different position in the direction of the rotational axis C1, and the area from the portion facing the lower part of the driven gear 27 to the meshing portion 15 is formed to be closer than the position of the inner surface of the first annular wall 10f in the direction of the rotational axis C1 excluding this range.

[0135] In Figure 3, the small gap 10g is shown as the small gap portion 10g of the first annular wall surface 10f where the gap S1 between the lower part of the driven gear 27 and the meshing portion 15 is smallest. The first annular wall surface 10f of the gap S2 excluding the gap between the lower part of the driven gear 27 and the meshing portion 15 constitutes the large gap portion 10h. As shown in Figure 6, the small gap portion 10g and the large gap portion 10h are connected by an inclined surface 10j.

[0136] When the driven gear 27 rotates in the clockwise direction R in Figure 3, the lubricating oil is scooped up by the teeth 27a of the driven gear 27. Note that the clockwise direction R shown in Figure 3 is the direction of rotation of the driven gear 27 when the vehicle is moving forward.

[0137] The gap S1 between the first annular wall surface 10f and the driven gear 27 is smallest between the lower part of the driven gear 27 and the meshing portion 15.

[0138] Furthermore, the twist direction of the teeth 27a is such that when rotated in the clockwise direction R, the first annular wall surface 10f side is behind. In other words, the teeth 27a are formed in a direction that directs the lubricating oil toward the vertical wall 10C of the left case portion 10B when the drive gear 12 rotates forward.

[0139] As a result, when the driven gear 27 rotates, it easily draws lubricating oil from the large gap 10h to the small gap 10g, and leakage is suppressed in the narrowed gap S1 between it and the first annular wall surface 10f, so the lubricating oil is easily retained and can be scraped up along the gap S1.

[0140] Furthermore, lubricating oil can be efficiently supplied to the meshing portion 15. In this embodiment, the gap S1 constitutes the first lubricating oil passage 51. In other words, the first lubricating oil passage 51 is formed between the lower part of the driven gear 27 and the meshing portion 15.

[0141] As shown in Figures 3 and 4, an inclined surface 10k is formed on the outer peripheral wall 10D. The inclined surface 10k is located downstream of the driven gear 27 in the rotational direction from the meshing portion 15, and is located above the driven gear 27, above the first annular wall surface 10f.

[0142] Here, since the lubricating oil flows (circulates) along the rotational direction of the driven gear 27 (clockwise rotation direction R shown in Figure 3), we assume that the lubricating oil starts flowing from the meshing portion 15, and the direction of the lubricating oil flow relative to the meshing portion 15 is defined as upstream and downstream.

[0143] For example, the inclined surface 10k side relative to the meshing portion 15 is the downstream side in the direction of lubrication oil flow, and the inclined surface 10j side relative to the meshing portion 15 is the upstream side in the direction of lubrication oil flow.

[0144] Furthermore, with respect to the inclined surface 10k, the meshing portion 15 side is upstream in the direction of lubrication oil flow, and with respect to the inclined surface 10j, the meshing portion 15 side is downstream in the direction of lubrication oil flow.

[0145] The inclined surface 10k is tilted in the direction of the rotational axis axis of the driven gear 27, moving away from the first annular wall surface 10f from the upstream end 10m to the downstream end 10n in the rotational direction of the driven gear 27.

[0146] In detail, the inclined surface 10k has its upstream end 10m positioned above the transmission 3 side end face of the driven gear 27 in the direction of the rotation center axis, and its downstream end 10n positioned above the internal combustion engine 1 side end face of the driven gear 27.

[0147] The outer peripheral wall 10D has a wall portion 10p. The wall portion 10p extends in the direction of the rotational center axis from the downstream end 10n of the inclined surface 10k away from the vertical wall 10C, and is located above the clutch input member 26 (see Figure 7).

[0148] Below the clutch input member 26, the input-side friction plate 30 and the output-side friction plate 31 are positioned, and the wall portion 10p is located above the input-side friction plate 30 and the output-side friction plate 31.

[0149] The lubricating oil, which has been scraped up by the driven gear 27 and lubricated the meshing portion 15, flows into the space where the inclined surface 10k is located, creating a radial depression in the outer peripheral wall 10D. The flowing lubricating oil then collides with the wall portion 10p, which has a surface formed along the inclined surface 10k so as to be opposite to the direction of flow.

[0150] Lubricating oil that collides with the wall portion 10p falls due to its own weight and is supplied to the input-side friction plate 30 and the output-side friction plate 31 through the space between the clutch input member 26 and the driven gear 27. The space formed by the inclined surface 10k and the wall portion 10p constitutes a second lubricating oil passage 52.

[0151] As shown in Figure 3, a groove 10q is formed in the vertical wall 10C. The groove 10q is located near the meshing portion 15.

[0152] Specifically, the groove 10q is located between the meshing portion 15 and the inclined surface 10k in the rotational direction of the driven gear 27, extends radially from the driven gear 27, passes through the outer annular projection 10E (described later) in a cut-through manner, and reaches the inner annular projection 10F. The radial outer end is bent toward the meshing portion 15. (See Figure 4)

[0153] The vertical wall 10C has an outer annular projection 10E and an inner annular projection 10F (see Figure 1), and the outer annular projection 10E and the inner annular projection 10F protrude concentrically from the vertical wall 10C toward the driven gear 27 with respect to the rotational axis C1.

[0154] As shown in Figure 1, the bearing fixing flange 35 is fitted into the inner diameter portion of the outer annular projection 10E, positioning the bearing fixing flange 35 in the radial direction.

[0155] The inner annular projection 10F is located radially inward of the outer annular projection 10E and abuts against the left end of the bearing 11D, with an oil seal 13B attached to its inner diameter. The right end of the bearing 11D abuts against the driven gear 27, and the bearing 11D is positioned in the direction of the rotational axis by the inner annular projection 10F and the outer disc portion 27A of the driven gear 27.

[0156] As shown in Figures 3 and 4, a second annular wall surface 10r is formed radially inward from the first annular wall surface 10f, between the outer annular projection 10E and the inner annular projection 10F, and the second annular wall surface 10r extends so as to surround the inner annular projection 10F.

[0157] The groove 10q extends from the first annular wall surface 10f along the radial direction of the vertical wall 10C to the bearing 11D (see Figure 8).

[0158] Specifically, the groove 10q is formed as a wide recess in the first annular wall surface 10f and the second annular wall surface 10r, and a portion of the outer annular projection 10E and the inner annular projection 10F are cut out so that lubricating oil near the meshing portion 15 can pass through and pass to the side of the bearing 11D.

[0159] As shown in Figure 5, a tongue portion 35C is formed on the bearing fixing flange 35. The tongue portion 35C protrudes radially outward from the annular portion 35A, covering the groove portion 10q on the first annular wall surface 10f side, and forming an opening that opens to face the meshing portion 15 with the groove portion 10q. This opening serves as the intake port for the lubricating oil of the third lubricating oil passage 53, which will be described later.

[0160] As shown in Figures 2 and 5, the annular portion 35A faces the second annular wall surface 10r in the direction of the rotational axis, and a portion of the annular portion 35A covers the groove portion 10q on the second annular wall surface 10r side. In other words, the bearing fixing flange 35 covers the groove portion 10q and the second annular wall surface 10r.

[0161] The space between the groove 10q and the tongue portion 35C and the annular portion 35A forms a third lubrication oil passage 53 (see Figure 8), and the lubricating oil that lubricates the meshing portion 15 is supplied through the third lubrication oil passage 53 to the space between the bearing 11D and the oil seal 13B.

[0162] As shown in Figures 2 and 5, a fourth lubricating oil passage 54 is formed between the second annular wall surface 10r and the annular portion 35A, and a portion of the lubricating oil flowing through the third lubricating oil passage 53 is introduced into the fourth lubricating oil passage 54.

[0163] A through hole 35a is formed in the lower part of the cylindrical portion 35B, and the through hole 35a connects the space between the bearing 11D and the oil seal 13B with the space 55 (see Figure 2) in which the release bearing 40 is located.

[0164] As a result, the lubricating oil flowing through the third lubricating oil passage 53 or the fourth lubricating oil passage 54 is supplied to the release bearing 40 through the through hole 35a.

[0165] As shown in Figure 1, the annular bearing support portion 10d protrudes from the vertical wall 10C toward the drive gear 12.

[0166] As shown in Figures 5 and 9, a radially penetrating notch 10s is formed in the bearing support portion 10d, and the notch 10s connects the inside and outside of the bearing support portion 10d.

[0167] The bearing 11B is positioned inside the bearing support portion 10d, and the lubricating oil directed to the vertical wall 10C by the drive gear 12 travels along the vertical wall 10C and is supplied to the bearing 11B through the notch 10s (see lubricating oil O5 in Figure 9). As a result, the bearing 11B is lubricated by the lubricating oil. In this embodiment, the bearing support portion 10d constitutes a second bearing support portion.

[0168] As shown in Figure 10, a notch 10t is formed in the cylindrical bearing support portion 10c that penetrates radially, and the notch 10t connects the inside and outside of the bearing support portion 10c.

[0169] The bearing 11A is positioned inside the bearing support portion 10c, and the lubricating oil wound up by the drive gear 12 is supplied between the bearing 11A and the oil seal 13A through the notch 10t (see lubricating oil O7 in Figure 10). As a result, the bearing 11A and the oil seal 13A are lubricated by the lubricating oil.

[0170] 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.

[0171] 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.

[0172] 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.

[0173] 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.

[0174] 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.

[0175] 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.

[0176] 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.

[0177] 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.

[0178] 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.

[0179] 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.

[0180] Next, the effects of the power transmission system 4 of the hybrid vehicle in this embodiment will be explained. Lubricating oil is stored at the bottom of case 10, and before starting the internal combustion engine 1, the oil level of the lubricating oil is located slightly below the rotational axis C1.

[0181] When the internal combustion engine 1 is operating at medium and high speeds, the lubricating oil level drops to a position lower than the release bearing 40, but the lower parts of the damper 21 and driven gear 27 are submerged in the lubricating oil. Therefore, the lubricating oil is constantly being stirred up by the driven gear 27.

[0182] 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 pair of reduction gears that transmit power between the motor generator 2 and the transmission 3, a release mechanism 36 that moves in the direction of the rotation center axis by rotation around the rotation center axis C1 to disconnect and reconnect the wet clutch 25, and a case 10 that houses the wet clutch 25, the pair of reduction gears, and the release mechanism 36.

[0183] The reduction gear pair includes a drive gear 12 to which power from the motor generator 2 is transmitted, and a driven gear 27 that meshes with the drive gear 12 and is linked to the transmission 3. The meshing portion 15 of the drive gear 12 and the driven gear 27 is located above the rotational axis of the driven gear 27 in a direction in which the teeth of the driven gear 27 move from bottom to top when the driven gear 27 rotates.

[0184] Case 10 has a vertical wall 10C facing the driven gear 27 in the direction of the rotational axis, and the vertical wall 10C has a first annular wall surface 10f that faces the teeth 27a of the driven gear 27 in the direction of the rotational axis and extends in the direction of rotation of the driven gear 27.

[0185] The gap S between the first annular wall surface 10f and the driven gear 27 is formed to be smallest at gap S1 from the lower part of the driven gear 27 to the meshing portion 15, and gap S1 constitutes a first lubrication oil passage 51 that supplies lubricating oil scraped up by the driven gear 27 to the meshing portion 15.

[0186] This allows the lubricating oil, which is scooped up by the driven gear 27, to be efficiently transported through the gap S1 to the meshing portion 15 (see lubricating oil O1 in Figure 3), and lubricating oil can be supplied to the meshing portion 15 without using an oil guide. As a result, the lubrication structure can be simplified and the power transmission device 4 can be made smaller.

[0187] 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, and 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.

[0188] The case 10 has an outer peripheral wall 10D that protrudes from the vertical wall 10C in the direction of the rotational axis and surrounds the radially outward sides of the drive gear 12 and the driven gear 27.

[0189] The outer peripheral wall 10D has a recess in its upper portion that forms a space where an inclined surface 10k is located. The inclined surface 10k is located downstream of the meshing portion 15 in the rotational direction of the driven gear 27, and above the first annular wall surface 10f, and is inclined away from the first annular wall surface 10f in the rotational direction of the driven gear 27, from the upstream end 10m to the downstream end 10n in the rotational direction of the rotational center axis.

[0190] The space in which the inclined surface 10k of the outer peripheral wall 10D is located further has a wall portion 10p. The wall portion 10p extends from the downstream end 10n of the inclined surface 10k to above the input-side friction plate 30 and the output-side friction plate 31, away from the vertical wall 10C, so as to face the flow of lubricating oil O2 shown in Figure 3.

[0191] The inclined surface 10k and the wall portion 10p constitute a second lubrication oil passage 52 that supplies the lubricating oil that has lubricated the meshing portion 15 to the input-side friction plate 30 and the output-side friction plate 31 through the space between the clutch input member 26 and the driven gear 27.

[0192] In this way, the lubricating oil that has lubricated the meshing portion 15 is allowed to fall towards the driven gear 27 through the second lubricating oil passage 52 and supplied to the input-side friction plate 30 and the output-side friction plate 31 through the space between the clutch input member 26 and the driven gear 27 (see lubricating oil O2 in Figures 3 and 7).

[0193] As a result, the input-side friction plate 30 and the output-side friction plate 31, which are located in positions where a shortage of lubricating oil is a concern, can be cooled and lubricated by the lubricating oil, thereby preventing seizure of the input-side friction plate 30 and the output-side friction plate 31.

[0194] Furthermore, any lubricating oil that is not supplied to the second lubricating oil passage 52 is returned to the bottom of the case 10 along the first annular wall surface 10f by the driven gear 27 and scraped up toward the meshing portion 15 by the driven gear 27 (see lubricating oil O6 in Figure 3). In this way, the lubricating oil is circulated along the first annular wall surface 10f by the driven gear 27.

[0195] Furthermore, the lubricating oil stored at the bottom of case 10 is stirred up by the driven gear 27, lowering the oil level. This reduces the stirring resistance of the damper 21 and driven gear 27, thereby reducing the fuel consumption of the internal combustion engine 1.

[0196] Furthermore, the power transmission device 4 of the hybrid vehicle in this embodiment has a bearing 11D that rotatably supports the driven gear 27 in the case 10.

[0197] The vertical wall 10C has a groove 10q located near the meshing portion 15, and the groove 10q extends from the first annular wall surface 10f along the radial direction of the vertical wall 10C to the bearing 11D.

[0198] The case 10 is attached to the vertical wall 10C so as to cover the groove 10q and has an annular bearing fixing flange 35 that positions the bearing 11D in the direction of the rotation center axis.

[0199] A third lubrication oil passage 53 is formed between the bearing fixing flange 35 and the groove 10q. The lubricating oil that lubricates the meshing portion 15 is taken in through an opening formed by the tongue portion 35C and the groove 10q, which opens toward the meshing portion 15, and supplied to the bearing 11D and the oil seal 13B through the third lubrication oil passage 53.

[0200] In this way, the lubricating oil that has lubricated the meshing portion 15 can be supplied to the bearing 11D through the third lubricating oil passage 53 (see lubricating oil O3 in Figures 3 and 8), and the bearing 11D can be lubricated by the lubricating oil.

[0201] Furthermore, according to the power transmission device 4 of the hybrid vehicle of this embodiment, the vertical wall 10C is located radially inward of the first annular wall surface 10f and has a second annular wall surface 10r that surrounds the inner annular projection 10F.

[0202] The bearing fixing flange 35 has an annular portion 35A that faces the second annular wall surface 10r in the direction of the rotational axis and forms a fourth lubrication oil passage 54 between it and the second annular wall surface 10r through which lubricating oil is introduced from the third lubrication oil passage 53. A cylindrical portion 35B is formed at the radially inner end of the annular portion 35A, which protrudes from the annular portion 35A toward the driven gear 27 and supports the bearing 11D radially inward.

[0203] The release mechanism 36 has a release bearing 40 located radially outward from the cylindrical portion 35B and positioned between the annular portion 35A and the driven gear 27 in the direction of the rotational axis, and a through hole 35a is formed in the cylindrical portion 35B to supply lubricating oil from the space between the bearing 11D and the oil seal 13B to the release bearing 40.

[0204] When lubricating oil is supplied from the third lubricating oil passage 53 to the fourth lubricating oil passage 54, the lubricating oil flows circumferentially along the fourth lubricating oil passage 54, and the lubricating oil that reaches the through hole 35a is supplied to the lower part of the release bearing 40 through the through hole 35a (see lubricating oil O4 in Figure 2).

[0205] Since the release bearing 40 rotates, the lubricating oil supplied to the bottom of the release bearing 40 spreads throughout the entire release bearing 40 as it rotates. As a result, the release bearing 40 can be lubricated by the lubricating oil.

[0206] Furthermore, according to the power transmission device 4 of this embodiment of the hybrid vehicle, the vertical wall 10C has a cylindrical bearing support portion 10d that rotatably supports the drive gear 12 via a bearing 11B, and the bearing support portion 10d has a notch 10s that penetrates in the radial direction.

[0207] This allows the lubricating oil wound up by the drive gear 12 to be supplied to the bearing 11B through the notch 10s (see lubricating oil O5 in Figures 3 and 9). As a result, the bearing 11B can be lubricated by the lubricating oil.

[0208] Furthermore, according to the power transmission device 4 of this embodiment of the hybrid vehicle, the drive gear 12 and the driven gear 27 are helical gears in which the helix angles of the teeth are the same and the helix directions of the teeth are opposite. The helix directions of the teeth 12a and 27a are formed in a direction that directs the lubricating oil toward the vertical wall 10C when the drive gear 12 and the driven gear 27 rotate. In other words, the lubricating oil present between the teeth is discharged by meshing, and this discharge direction is toward the vertical wall 10C.

[0209] This allows the lubricating oil to be easily directed to the vertical wall 10C by the rotation of the drive gear 12 and the driven gear 27, enabling efficient lubrication of lubrication and cooling parts with a simple lubrication structure.

[0210] As described above, the power transmission device 4 of this embodiment can supply lubricating oil to the lubrication and cooling parts of the power transmission device 4 by eliminating the oil guide. This simplifies the lubrication structure of the power transmission device 4, eliminates the need for space to place the oil guide, and allows for miniaturization of the power transmission device 4.

[0211] 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]

[0212] 1. Internal combustion engine 2. Motor Generator (Rotating Electric Machine) 3. Transmission 4. Power transmission device 10 cases 10C vertical wall 10D outer wall 10d Bearing support section (second bearing support section) 10f First ring wall 10k slope 10p wall 10q Groove 10r Second annular wall 10s notch 11D bearing 12. Drive gears (reduction gear pairs, helical gears) 15. Engagement part 25 Wet clutch (clutch) 26 Clutch input member 27. Driven gear (reducing gear pair, helical gear) 30 Input side friction plate (friction member) 31 Output side friction plate (friction member) 35 Bearing fixing flange 35A Annular section 35a through hole 35B Cylindrical section (first bearing support section) 36. Release mechanism (release component) 40 Release Bearing 51 First lubrication passage 52 Second lubrication passage 53 Third lubrication passage 54. Fourth lubrication passage C1 Clutch rotation center axis S Gap (the gap between the first annular wall and the driven gear)

Claims

1. The device 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 moves in the direction of the rotation center of the clutch by rotation around the rotation center axis of the clutch, thereby disconnecting and reconnecting the clutch; and a case that houses the clutch, the pair of reduction gears, and the release member. The aforementioned reduction gear pair is, A power transmission device for a hybrid vehicle, comprising a drive gear to which power from the aforementioned rotating electric machine is transmitted, and a driven gear that meshes with the drive gear and is linked to the transmission, wherein the meshing portion of the drive gear and the driven gear is located above the rotational axis of the driven gear in the direction in which the teeth of the driven gear move from bottom to top when the driven gear rotates, The case has a vertical wall facing the driven gear in the direction of the rotational axis of the driven gear, The vertical wall has a first annular wall surface that faces the teeth of the driven gear in the direction of the rotational axis of the driven gear and extends in the rotational direction of the driven gear. The gap between the first annular wall surface and the driven gear is smallest between the lower part of the driven gear and the meshing portion. The power transmission device for a hybrid vehicle is characterized in that the gap constitutes a first lubrication passage that supplies lubricating oil, which is scraped up by the driven gear, to the meshing portion.

2. The aforementioned clutch is A clutch input member to which power is transmitted from the internal combustion engine, The driven gear and, The system includes a friction member that disconnects the clutch input member and the driven gear, The case has an outer peripheral wall that protrudes from the vertical wall in the direction of the rotation center axis of the driven gear and surrounds the radially outward sides of the drive gear and the driven gear. The outer peripheral wall has an inclined surface, which is located downstream of the meshing portion in the rotational direction of the driven gear and above the first annular wall surface, and is inclined away from the first annular wall surface in the rotational direction of the driven gear from the upstream end to the downstream end in the rotational direction of the driven gear, The outer peripheral wall has a wall portion, and the wall portion extends from the downstream end of the inclined surface to above the friction member so as to be separated from the vertical wall. The power transmission device for a hybrid vehicle according to claim 1, characterized in that the inclined surface and the wall portion constitute a second lubricating oil passage that supplies the lubricating oil that has lubricated the meshing portion to the friction member through the space between the clutch input member and the driven gear.

3. The case has a bearing that rotatably supports the driven gear, The vertical wall has a groove located near the meshing portion, and the groove extends from the first annular wall surface along the radial direction of the vertical wall to the bearing. The case is mounted on the vertical wall so as to cover the groove and has an annular bearing fixing flange that positions the bearing in the direction of the rotation center axis of the driven gear. A third lubrication oil passage is formed between the bearing fixing flange and the groove. The power transmission device for a hybrid vehicle according to claim 1 or 2, characterized in that the lubricating oil that has lubricated the meshing portion is supplied to the bearing through the third lubricating oil passage.

4. The vertical wall has a second annular wall that is located radially inward of the first annular wall surface and extends in the rotational direction of the driven gear. The bearing fixing flange has an annular portion that faces the second annular wall surface in the axial direction of the rotation center of the driven gear and forms a fourth lubrication oil passage between itself and the second annular wall surface, through which lubricating oil is introduced from the third lubrication oil passage. A cylindrical first bearing support portion is formed at the radially inner end of the annular portion, protruding from the annular portion toward the driven gear and supporting the bearing radially inward. The release member has a release bearing located radially outward from the first bearing support portion and positioned between the annular portion and the driven gear in the direction of the rotation center axis of the driven gear. The power transmission device for a hybrid vehicle according to claim 3, characterized in that the first bearing support portion is formed with a through hole for supplying lubricating oil flowing through the fourth lubricating oil passage to the release bearing.

5. The aforementioned vertical wall has a cylindrical second bearing support portion that rotatably supports the drive gear via a bearing, The power transmission device for a hybrid vehicle according to claim 1 or 2, characterized in that the second bearing support portion has a radially penetrating notch.

6. The drive gear and the driven gear are composed of helical gears in which the helix angles of the teeth are the same and the helix directions of the teeth are opposite. The power transmission device for a hybrid vehicle according to claim 1 or 2, characterized in that the twist direction of each tooth is formed in a direction that directs lubricating oil towards the vertical wall when the drive gear and the driven gear rotate.

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