Vehicle drive transmission device

Abstract

To reduce an axial load acting on a shaft member that supports a gear composed of helical gears.SOLUTION: A meshing portion between a first gear (25) and a second gear (3A) is configured such that a helical orientation of the first gear (25) and a helical orientation of the second gear (3A) are set so that the first gear (25) receives an axial load acting from a second axial side (L2) toward a first axial side (L1), and a piston portion (P) presses a pair of friction members toward the axial second side (L2).SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a vehicle drive transmission device. [Background technology]

[0002] An example of a vehicle drive transmission device is disclosed in JP-T-2016-516161 (Patent Document 1).

[0003] In the vehicle drive transmission device disclosed in Patent Document 1, a form-fitting shift element [5] (mesh-type engagement device) selectively connects either an idler gear [7] or an idler gear [8] to an input shaft [2], thereby enabling two-speed shifting. When shifting gears, a friction-fitting shift element [6] (friction engagement device) is engaged to perform rotation synchronization control in order to smoothly perform the shift.

[0004] In the vehicle drive transmission device described above, the gears arranged on different shafts (including virtual shafts) and meshing with each other are often configured with helical gears from the viewpoint of noise reduction, etc. In this case, an axial load (thrust load) acts on the gears and the shaft member supporting the gears due to the meshing of the gears. Such a shaft member is usually supported rotatably by a support bearing. When a large axial load acts on the shaft member, the load on the support bearing supporting the shaft member also becomes large. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2016-516161 Summary of the Invention [Problem to be solved by the invention]

[0006] Therefore, it is desirable to realize a technology that can reduce the axial load acting on a shaft member that supports a gear composed of a helical gear. [Means for solving the problem]

[0007] A vehicle drive transmission device according to the present disclosure includes: a first gear which is a helical gear supported by a shaft member; a second gear which is a helical gear meshing with the first gear; a support bearing that rotatably supports the shaft member; a friction engagement device supported by the shaft member, A direction along the rotation axis of the shaft member is defined as an axial direction, one side in the axial direction is defined as an axial first side, and the other side in the axial direction is defined as an axial second side, The friction engagement device includes a pair of friction members supported so as to be rotatable relative to one another, and a piston portion that presses the pair of friction members in the axial direction so as to press them against each other, a helical direction of the first gear and a helical direction of the second gear are set so that the first gear receives an axial load acting from the second axial side toward the first axial side at a meshing portion between the first gear and the second gear, The piston portion is configured to press the pair of friction members toward the second axial side.

[0008] Due to the meshing of the first gear and the second gear, an axial load acts on the shaft member from the second axial side to the first axial side. However, according to this configuration, the piston portion of the friction engagement device presses the pair of friction members toward the second axial side, so that an axial load acting in the opposite direction to the axial load caused by the meshing of the first gear and the second gear can be applied to the shaft member. Therefore, according to this configuration, when the piston portion presses the pair of friction members, the axial load acting on the shaft member can be reduced. As a result, the load acting on the support bearing that supports the shaft member can be reduced.

[0009] Further features and advantages of the techniques disclosed herein will become more apparent from the following description of exemplary and non-limiting embodiments, which proceeds with reference to the drawings. [Brief description of the drawings]

[0010] [Figure 1] Skeleton diagram of a vehicle drive transmission device [Diagram 2] Cross-sectional view of a vehicle drive transmission device [Diagram 3] FIG. 13 is an enlarged cross-sectional view of the vehicle drive transmission device, showing a state in which a piston portion is pressed. [Figure 4] FIG. 13 is an enlarged cross-sectional view of the vehicle drive transmission device, showing a piston portion in a non-pressed state; [Diagram 5] Schematic diagram of a vehicle drive transmission device as viewed from an axial direction. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] An embodiment of a drive transmission device for a vehicle will be described with reference to the drawings. As shown in Figs. 1 and 2, a drive transmission device 100 for a vehicle according to this embodiment generally includes a transmission 1, a rotating electric machine 2, a differential gear mechanism 3, and a pair of output members 4 each of which is drivingly connected to wheels W. The transmission 1 also includes an input member 10 including a fifth gear 12 and a sixth gear 14, a shaft member 20 supporting a third gear 22 and a fourth gear 24 and including a first gear 25, a meshing engagement device 30, and a friction engagement device 40. These are housed in a case (drive device case) 6. A part of the output member 4 is exposed to the outside of the case 6. In this embodiment, the rotating electric machine 2 corresponds to a "driving force source."

[0012] Thus, the vehicle drive transmission device 100 includes the first gear 25 supported by the shaft member 20, the second gear 3A meshing with the first gear 25, and the friction engagement device 40 supported by the shaft member 20. In this embodiment, the vehicle drive transmission device 100 also includes the third gear 22 and the fourth gear 24 supported by the shaft member 20, the fifth gear 12 meshing with the third gear 22, and the sixth gear 14 meshing with the fourth gear 24.

[0013] Here, the term "rotating electric machine" is used as a concept that includes motors, generators, and motor-generators that function as both a motor and a generator as necessary.

[0014] Moreover, "driving connection" refers to a state in which two rotating elements are connected so as to be able to transmit a driving force. This concept includes a state in which two rotating elements are connected so as to rotate together, and a state in which two rotating elements are connected so as to be able to transmit a driving force via one or more transmission members. Such transmission members include various members (shafts, gear mechanisms, belts, chains, etc.) that transmit rotation at the same speed or at a variable speed, and may also include engagement devices (friction engagement devices, meshing engagement devices, etc.) that selectively transmit rotation and driving force.

[0015] The rotating electric machine 2 and the input member 10 are disposed on the first axis X1. The shaft member 20, the meshing type engagement device 30, and the friction engagement device 40 are disposed on the second axis X2. The differential gear mechanism 3 and the output member 4 are disposed on the third axis X3. The first axis X1, the second axis X2, and the third axis X3 are mutually different parallel axes, and are disposed parallel to the rotation axis of the shaft member 20. In the following, the direction along the rotation axis of the shaft member 20 is referred to as the "axial direction L", one side of the axial direction L is referred to as the "axial first side L1", and the other side of the axial direction L is referred to as the "axial second side L2". Here, the left side of FIG. 1 corresponds to the axial first side L1, and the right side of FIG. 1 corresponds to the axial second side L2. In the following, the state seen along the axial direction L is referred to as the "axial view". In addition, in the following, the direction perpendicular to the rotation axis of the shaft member 20 is referred to as the radial direction R.

[0016] The rotating electric machine 2 includes a stator 2A fixed to a case 6, and a rotor 2B rotatably supported radially inside the stator 2A. The rotating electric machine 2 receives power from an electric storage device (not shown) for power running, or supplies electric power generated by the inertial force of the vehicle or the like to the electric storage device for storage. The rotor 2B is connected to a rotor shaft 2C so as to rotate integrally therewith. The rotor shaft 2C is supported rotatably relative to the case 6 at two points in the axial direction L by rotor bearings 91 (see FIG. 2). The rotor shaft 2C is connected to an input member 10 of the transmission 1 at an end on a first axial side L1 so as to rotate integrally therewith.

[0017] The transmission 1 changes the speed of the rotation from the rotating electric machine 2 and transmits it to the wheels W. The transmission 1 of this embodiment includes an input member 10 including a fifth gear 12 and a sixth gear 14, a shaft member 20 supporting a third gear 22 and a fourth gear 24 and including a first gear 25, a meshing engagement device 30, and a friction engagement device 40. The meshing engagement device 30 selectively couples either the third gear 22 or the fourth gear 24 to the shaft member 20, so that the transmission 1 can change the speed of the rotation from the rotating electric machine 2 in two stages and transmit it to the wheels W. The friction engagement device 40 is engaged when the meshing engagement device 30 couples the fourth gear 24 to the shaft member 20, thereby synchronizing the rotational speeds of the fourth gear 24 and the shaft member 20.

[0018] In this embodiment, the meshing type engagement device 30 is disposed between the third gear 22 and the fourth gear 24 in the axial direction L. The friction engagement device 40 is disposed on a first axial side L1 with respect to the third gear 22 and the fourth gear 24. The first gear 25 is disposed on a second axial side L2 with respect to the third gear 22 and the fourth gear 24. That is, the first gear 25 is disposed on the second axial side L2 with respect to the friction engagement device 40, and the friction engagement device 40 is disposed on the first axial side L1 with respect to the first gear 25.

[0019] The first gear 25 is supported by the shaft member 20 in a state in which relative movement therebetween is restricted at least in the axial direction L. In this embodiment, the first gear 25 is formed integrally with the shaft member 20.

[0020] The differential gear mechanism 3 includes a second gear 3A, and distributes and transmits the rotation and torque input from the transmission 1 to a pair of output members 4. The second gear 3A is configured as a so-called differential input gear. The pair of output members 4 are each drivingly connected to wheels W. In this manner, the rotation transmitted from the rotating electric machine 2 is transmitted to the differential gear mechanism 3 via the transmission 1, and is further distributed to the pair of output members 4 by the differential gear mechanism 3, and is further transmitted to the pair of wheels W. In this manner, the vehicle drive transmission device 100 can transmit the torque of the rotating electric machine 2 to the wheels W to run the vehicle.

[0021] As shown in FIG. 2, the case 6 includes a first case portion 6A, a second case portion 6B, and a third case portion 6C. The first case portion 6A is joined to the second case portion 6B from the first axial side L1. The first case portion 6A houses the transmission 1 and the differential gear mechanism 3. The first case portion 6A includes a first peripheral wall portion 6Aa that covers the radial outside of the transmission 1 and the differential gear mechanism 3, and a first support wall portion 6Ab that covers the first axial side L1 of the transmission 1 and the differential gear mechanism 3. The second case portion 6B houses the rotating electric machine 2. The second case portion 6B includes a second peripheral wall portion 6Ba that covers the radial outside of the rotating electric machine 2, and a second support wall portion 6Bb that covers the second axial side L2 of the rotating electric machine 2. In the illustrated example, the transmission 1 and a part of the differential gear mechanism 3 are also housed in the second case portion 6B. The third case portion 6C separates an accommodation space for the transmission 1 and the differential gear mechanism 3 from an accommodation space for the rotating electric machine 2 inside the first case portion 6A and the second case portion 6B.

[0022] The input member 10 functions as a member (a transmission input member in the transmission 1) to which a driving force is input from a driving force source (here, the rotating electric machine 2). The input member 10 is disposed on the first axial side L1 with respect to the rotor shaft 2C. The input member 10 is connected to the rotor shaft 2C so as to rotate integrally with the rotor shaft 2C with an end of the input member 10 on the second axial side L2 inserted into the rotor shaft 2C. The input member 10 is rotatably supported with respect to the case 6 by input bearings 92 at two points in the axial direction L. The input member 10 is rotatably supported with respect to the first case portion 6A on the first axial side L1, and rotatably supported with respect to the third case portion 6C on the second axial side L2.

[0023] In this embodiment, the first support wall 6Ab of the first case portion 6A is formed with a first cylindrical support portion 61 that protrudes toward the second axial side L2 (see FIG. 3). One of the pair of input bearings 92 is fitted into the first cylindrical support portion 61.

[0024] The fifth gear 12 and the sixth gear 14 are connected to the input member 10 so as to rotate integrally with the input member 10. In this embodiment, the fifth gear 12 is formed on the outer peripheral surface of the input member 10. The fifth gear 12 meshes with the third gear 22. The sixth gear 14 is formed on the outer peripheral surface of a second gear forming member 13 connected to the input member 10 so as to rotate integrally with the input member 10. The sixth gear 14 meshes with the fourth gear 24. The sixth gear 14 is disposed at a distance from the fifth gear 12 on the first axial side L1.

[0025] The shaft member 20 is disposed in parallel with the input member 10. The arrangement area of ​​the shaft member 20 in the axial direction L overlaps with the arrangement area of ​​the input member 10 in the axial direction L. In this embodiment, the arrangement area of ​​the shaft member 20 in the axial direction L is included in the arrangement area of ​​the input member 10 in the axial direction L. The shaft member 20 is rotatably supported by the support bearings 93 at two points in the axial direction L with respect to the case 6. The shaft member 20 is rotatably supported with respect to the first case portion 6A on the first axial side L1, and is rotatably supported with respect to the third case portion 6C on the second axial side L2. In this manner, the vehicle drive transmission device 100 includes the support bearings 93 that rotatably support the shaft member 20.

[0026] In this embodiment, the support bearing 93 includes a first bearing 931 arranged on a first axial side L1 relative to the first gear 25, and a second bearing 932 arranged on a second axial side L2 relative to the first gear 25.

[0027] The first bearing 931 is configured to restrict the movement of the shaft member 20 toward the first axial side L1. In this embodiment, the shaft member 20 is formed with a first step portion 26 having a surface facing the first axial side L1. The diameter of the outer circumferential surface of the shaft member 20 on the first axial side L1 from the first step portion 26 is formed smaller than the diameter of the outer circumferential surface of the shaft member 20 on the second axial side L2 from the first step portion 26. As a result, the first step portion 26 is formed with a surface facing the first axial side L1. The first bearing 931 abuts against the surface of the first step portion 26 facing the first axial side L1 from the first axial side L1.

[0028] In this embodiment, the first bearing 931 is supported in the radial direction R by the case 6 (first support wall portion 6Ab in this example) and is supported from the first axial side L1. As a result, the shaft member 20 is supported in the radial direction R with respect to the case 6 via the first bearing 931 and is supported from the first axial side L1. In this manner, the first bearing 931 is configured to restrict movement of the shaft member 20 toward the first axial side L1. In the illustrated example, the first bearing 931 is supported from the first axial side L1 by the first support wall portion 6Ab via a spacer, but may be supported directly without via another member such as a spacer.

[0029] The second bearing 932 is configured to restrict the movement of the shaft member 20 toward the second axial side L2. As shown in FIG. 2, in this embodiment, the shaft member 20 is formed with a second step portion 27 having a surface facing the second axial side L2. The diameter of the outer circumferential surface of the shaft member 20 on the second axial side L2 from the second step portion 27 is formed smaller than the diameter of the outer circumferential surface of the shaft member 20 on the first axial side L1 from the second step portion 27. As a result, the second step portion 27 is formed with a surface facing the second axial side L2. The second bearing 932 abuts against the surface of the second step portion 27 facing the second axial side L2 from the second axial side L2.

[0030] In this embodiment, the second bearing 932 is supported by the case 6 (the third case portion 6C in this example) in the radial direction R and from the second axial side L2. As a result, the shaft member 20 is supported by the case 6 in the radial direction R and from the second axial side L2 via the second bearing 932. In this manner, the second bearing 932 is configured to restrict movement of the shaft member 20 toward the second axial side L2. In the illustrated example, the second bearing 932 is supported by the third case portion 6C from the second axial side L2, but may be supported by another portion of the case 6 or indirectly supported via another member supported by the case 6.

[0031] In this embodiment, the first support wall portion 6Ab of the first case portion 6A is formed with a cylindrical second support portion 62 that protrudes toward the second axial side L2 (see FIG. 3). One of the pair of support bearings 93 is fitted into the second cylindrical support portion 62. In this example, the first bearing 931 is fitted into the second cylindrical support portion 62.

[0032] The third gear 22 and the fourth gear 24 are supported by the shaft member 20 in a state in which they can rotate relative to the shaft member 20. In this embodiment, the third gear 22 is formed on the outer circumferential surface of a third gear forming member 21 rotatably supported on the shaft member 20 via a bearing. The third gear 22 meshes with the fifth gear 12. The fourth gear 24 is formed on the outer circumferential surface of a fourth gear forming member 23 rotatably supported on the shaft member 20 via a bearing. The fourth gear 24 meshes with the sixth gear 14. The fourth gear 24 is disposed at a distance from the third gear 22 on the first axial side L1. In the illustrated example, needle roller bearings are used for the bearings supporting the third gear forming member 21 and the fourth gear forming member 23.

[0033] In this embodiment, the fifth gear 12 has a smaller diameter than the sixth gear 14, and the third gear 22 has a larger diameter than the fourth gear 24 correspondingly.

[0034] The first gear 25 is connected to the shaft member 20 so as to rotate integrally with the shaft member 20. In this embodiment, the first gear 25 is formed on the outer circumferential surface of the shaft member 20. The first gear 25 is formed at a position adjacent to the second axial side L2 of the third gear forming member 21 on which the third gear 22 is formed. The first gear 25 functions as a member (transmission output member) for outputting a driving force to the outside of the transmission 1. The first gear 25 meshes with the second gear 3A of the differential gear mechanism 3.

[0035] As shown in FIG. 3, the meshing engagement device 30 includes a first engagement portion 31, a second engagement portion 32, a third engagement portion 33, and a switching member .

[0036] The first engagement portion 31 is connected to the shaft member 20 so as to rotate integrally with the shaft member 20. In this embodiment, the first engagement portion 31 is formed on the outer circumferential surface of a connecting member 31A connected to the shaft member 20 so as to rotate integrally with the shaft member 20. The first engagement portion 31 is an externally toothed engagement portion.

[0037] The second engagement portion 32 is connected to the third gear 22 so as to rotate integrally with the third gear 22. In this embodiment, the second engagement portion 32 is formed on a third gear forming member 21 having the third gear 22 formed on its outer circumferential surface. The second engagement portion 32 is disposed adjacent to the first engagement portion 31 on the second axial side L2. The second engagement portion 32 is an externally toothed engagement portion having the same diameter and pitch as the first engagement portion 31.

[0038] The third engagement portion 33 is connected to the fourth gear 24 so as to rotate integrally with the fourth gear 24. In this embodiment, the third engagement portion 33 is formed on a fourth gear forming member 23 having the fourth gear 24 formed on its outer circumferential surface. The third engagement portion 33 is disposed adjacent to the first engagement portion 31 on the first axial side L1. The third engagement portion 33 is an engagement portion with external teeth having the same diameter and pitch as the first engagement portion 31 and the second engagement portion 32.

[0039] The switching member 35 is formed in a cylindrical shape covering the outside of the connecting member 31A in the radial direction R. Then, on the inner peripheral surface of the switching member 35, internal tooth engaging portions are formed which mesh with the first engaging portion 31, the second engaging portion 32, and the third engaging portion 33 of the external teeth, respectively. The internal teeth of the switching member 35 and the external teeth of the first engaging portion 31, the second engaging portion 32, and the third engaging portion 33 engage with each other so as to be relatively movable in the axial direction L and relatively unrotatable in the circumferential direction.

[0040] The meshing engagement device 30 connects the third gear 22 and the shaft member 20 so as to rotate integrally with each other in a state where the switching member 35 is engaged with both the first engagement portion 31 and the second engagement portion 32. The meshing engagement device 30 connects the fourth gear 24 and the shaft member 20 so as to rotate integrally with each other in a state where the switching member 35 is engaged with both the first engagement portion 31 and the third engagement portion 33. In this manner, the meshing engagement device 30 selectively connects either the third gear 22 or the fourth gear 24 to the shaft member 20. In a state where the third gear 22 and the shaft member 20 are connected so as to rotate integrally with each other, the driving force of the rotating electric machine 2 is transmitted to the wheel W side via the fifth gear 12 and the third gear 22 which mesh with each other. On the other hand, when the fourth gear 24 and the shaft member 20 are connected so as to rotate integrally, the driving force of the rotating electric machine 2 is transmitted to the wheel W side via the sixth gear 14 and the fourth gear 24 which mesh with each other.

[0041] When the switching member 35 is engaged with the first engagement portion 31 but not engaged with either the second engagement portion 32 or the third engagement portion 33, the meshing engagement device 30 is in a disengaged state (disengaged state). When the meshing engagement device 30 is in a disengaged state and the friction engagement device 40 is also in a disengaged state, the transmission 1 is in a neutral state in which it does not transmit driving force.

[0042] As shown in FIGS. 3 and 4, the friction engagement device 40 includes a first support member 41, a second support member 42, a first friction material 43, a second friction material 44, and a piston portion P.

[0043] The first support member 41 is a member for supporting the first friction material 43, and is supported rotatably. The first support member 41 includes a first friction material support portion 41A, a first radial extension portion 41B, a shaft connecting portion 41C, and an axial support portion 41D. These are integrally formed. The first friction material support portion 41A is formed in a cylindrical shape along the axial direction L, and supports the first friction material 43 from the inside in the radial direction R. External teeth are formed on the outer peripheral surface of the first friction material support portion 41A. With these configurations, the first support member 41 supports the first friction material 43 in the radial direction R and the circumferential direction. The first radial extension portion 41B extends from the first friction material support portion 41A toward the inside in the radial direction R. In this embodiment, the first radial extension portion 41B extends from the end of the axial second side L2 of the first friction material support portion 41A toward the inside in the radial direction R.

[0044] The shaft connecting portion 41C extends in the axial direction L from a lower end of the first radially extending portion 41B. The shaft connecting portion 41C is formed in a cylindrical shape along the axial direction L, and is extrapolated onto the shaft member 20. The shaft connecting portion 41C is connected to the shaft member 20 so as to rotate integrally therewith. As a result, the entire first support member 41 is connected to the shaft member 20 so as to rotate integrally therewith. Of the portions constituting the first support member 41, the first radially extending portion 41B is disposed on a second axial side L2 with respect to the piston portion P.

[0045] The axial support portion 41D supports the first friction material 43 and the second friction material 44 from the opposite side in the axial direction L from the piston portion P (the second axial side L2 in this example) with the first friction material 43 and the second friction material 44 sandwiched therebetween. Here, the second friction material 44 is supported in the radial direction R and the circumferential direction by the second support member 42, as described later. The axial support portion 41D is configured to support the first friction material 43 supported by the first support member 41, as well as the second friction material 44 supported by the second support member 42, from the second axial side L2. That is, the first support member 41 supports both the first friction material 43 and the second friction material 44 from the second axial side L2. In this example, the axial support portion 41D is formed continuously to the first friction material support portion 41A on the second axial side L2, and is formed continuously to the outside in the radial direction R with respect to the first radial extension portion 41B. In this embodiment, the first support member 41 corresponds to the "inner support member."

[0046] In this embodiment, an intermediate step portion 28 having a surface facing the axial first side L1 is formed in the portion of the shaft member 20 where the first support member 41 is supported. The intermediate step portion 28 is disposed between the first step portion 26 and the second step portion 27 in the axial direction L. The diameter of the outer peripheral surface of the shaft member 20 on the axial first side L1 from the intermediate step portion 28 is smaller than the diameter of the outer peripheral surface of the shaft member 20 on the axial second side L2 from the intermediate step portion 28. As a result, a surface facing the axial first side L1 is formed in the intermediate step portion 28. The first support member 41 abuts against the surface facing the axial first side L1 of the intermediate step portion 28 from the axial first side L1. As a result, in this example, the first support member 41 is supported by the shaft member 20 in a state in which movement toward the axial second side L2 with respect to the shaft member 20 is restricted.

[0047] The second support member 42 is a member for supporting the second friction material 44, and is supported rotatably independent of the first support member 41. The second support member 42 includes a second friction material support portion 42A and a second radially extending portion 42B. These are integrally formed. The second friction material support portion 42A is formed in a cylindrical shape along the axial direction L, and supports the second friction material 44 from the outside in the radial direction R. Internal teeth are formed on the inner peripheral surface of the second friction material support portion 42A. With these configurations, the second support member 42 supports the second friction material 44 in the radial direction R and the circumferential direction. The second friction material support portion 42A is disposed coaxially with the first friction material support portion 41A, outside the radial direction R of the first friction material support portion 41A.

[0048] The second radial extension portion 42B extends from the second friction material support portion 42A toward the inside in the radial direction R. In this embodiment, the second radial extension portion 42B extends from the end of the second axial side L2 of the second friction material support portion 42A toward the inside in the radial direction R. The second radial extension portion 42B is disposed adjacent to the second axial side L2 with respect to the first radial extension portion 41B. Also, the second radial extension portion 42B is disposed adjacent to the first axial side L1 with respect to the fourth gear forming member 23. The second radial extension portion 42B is connected to the fourth gear forming member 23 on which the fourth gear 24 is formed so as to rotate integrally. As a result, the entire second support member 42 is connected to the fourth gear 24 so as to rotate integrally. In this embodiment, the second support member 42 corresponds to the "outer support member".

[0049] A plurality of first friction materials 43 are arranged side by side in the axial direction L. Internal teeth that mesh with the external teeth of the first friction material support portion 41A are formed on the inner peripheral surface of each first friction material 43. The first friction material 43 is supported on the outer peripheral surface of the first friction material support portion 41A so as to be movable relative to the first friction material support portion 41A in the axial direction L but not rotatable relative to the first friction material support portion 41A in the circumferential direction.

[0050] The second friction materials 44 are arranged in a row in the axial direction L. The first friction materials 43 and the second friction materials 44 are arranged alternately in the axial direction L and are arranged to face each other in the axial direction L. External teeth that mesh with the internal teeth of the second friction material support portion 42A are formed on the outer circumferential surface of each second friction material 44. The second friction material 44 is supported on the inner circumferential surface of the second friction material support portion 42A so as to be movable relative to the second friction material support portion 42A in the axial direction L and not rotatable relative to the second friction material support portion 42A in the circumferential direction. In this embodiment, the first friction material 43 and the second friction material 44 correspond to a "pair of friction members". The first friction material 43 corresponds to "one of the pair of friction members" and the second friction material 44 corresponds to "the other of the pair of friction members".

[0051] Thus, the friction engagement device 40 includes a pair of friction members supported so as to be rotatable relative to one another, an inner support member that supports one of the pair of friction members from the inside in the radial direction R, and an outer support member that supports the other of the pair of friction members from the outside in the radial direction R.

[0052] The piston portion P is configured to press the first friction material 43 and the second friction material 44 in the axial direction L so as to press them against each other. That is, the friction engagement device 40 includes the piston portion P that presses the first friction material 43 and the second friction material 44 in the axial direction L so as to press them against each other. In this embodiment, the piston portion P includes a first pressing member 45, a second pressing member 46, and a pressing drive portion 49. Note that Figs. 2 and 3 show a pressing state in which the piston portion P presses the first friction material 43 and the second friction material 44. Fig. 4 shows a non-pressing state in which the piston portion P does not press the first friction material 43 and the second friction material 44.

[0053] The first pressing member 45 cooperates with the second pressing member 46 to press the first friction material 43 and the second friction material 44 against each other. The first pressing member 45 is disposed on the first axial side L1 with respect to the first friction material 43 and the second friction material 44. The first pressing member 45 has internal teeth that mesh with the external teeth of the first friction material support portion 41A, and is supported so as to be movable relative to the first friction material support portion 41A in the axial direction L and not rotatable relative to the first friction material support portion 41A in the circumferential direction. In this way, the first pressing member 45 rotates integrally with the first support member 41 and is supported so as to be movable in the axial direction L with respect to the first support member 41. When the first pressing member 45 is driven in the axial direction L by the pressing drive portion 49 via the second pressing member 46, it presses the first friction material 43 and the second friction material 44 from the first axial side L1 to press the first friction material 43 and the second friction material 44 against each other.

[0054] The first pressing member 45 includes a sliding portion 45A and a pressing portion 45B. The sliding portion 45A is disposed inward of the first frictional material support portion 41A in the radial direction R, and slides along the inner circumferential surface of the first frictional material support portion 41A. In this embodiment, a seal member 51 is disposed between a surface (sliding facing surface) of the sliding portion 45A facing the inner circumferential surface of the first frictional material support portion 41A and the inner circumferential surface of the first frictional material support portion 41A. The sliding portion 45A is formed so as to extend along the radial direction R. In this example, the sliding portion 45A is formed along the radial direction R so as to span the first frictional material support portion 41A and the shaft connecting portion 41C of the first support member 41. The sliding portion 45A is biased toward the first axial side L1 by a biasing member 48 held by a holding member 47. The biasing member 48 biases the first pressing member 45 in the axial direction L in the opposite direction to the side where the first friction material 43 and the second friction material 44 are pressed against each other. In this embodiment, a return spring (coil spring) is used as such a biasing member 48.

[0055] The pressing portion 45B extends outward in the radial direction R from the sliding portion 45A. The pressing portion 45B is disposed outward in the radial direction R from the first friction material support portion 41A. The pressing portion 45B is formed to have a portion disposed between the first friction material support portion 41A and the second friction material support portion 42A in the radial direction R. The pressing portion 45B moves along the axial direction L integrally with the sliding portion 45A to press the first friction material 43 and the second friction material 44.

[0056] The second pressing member 46 cooperates with the first pressing member 45 to press the first friction material 43 and the second friction material 44 against each other. The second pressing member 46 is disposed on the first axial side L1 with respect to the first pressing member 45. In this embodiment, the second pressing member 46 is disposed adjacent to the first pressing member 45 with a thrust bearing 95 interposed therebetween. The second pressing member 46 is supported on the case 6 so as to be movable in the axial direction L. The first support wall 6Ab of the first case portion 6A is formed with a third cylindrical support portion 63 that is cylindrical and protrudes to the second axial side L2. The third cylindrical support portion 63 is formed concentrically with the second cylindrical support portion 62 and has a larger diameter than the second cylindrical support portion 62. The second pressing member 46 is disposed in an annular space between the second cylindrical support portion 62 and the third cylindrical support portion 63 in the radial direction R.

[0057] The second pressing member 46 slides along the inner peripheral surface of the third cylindrical support portion 63 and the outer peripheral surface of the second cylindrical support portion 62. In this embodiment, a seal member 52 is disposed between a surface of the second pressing member 46 facing the inner peripheral surface of the third cylindrical support portion 63 and the inner peripheral surface of the third cylindrical support portion 63. Also, a seal member 53 is disposed between a surface of the second pressing member 46 facing the outer peripheral surface of the second cylindrical support portion 62 and the outer peripheral surface of the second cylindrical support portion 62. The second pressing member 46 is supported in a non-rotating state so as to be movable in the axial direction L.

[0058] The pressing drive unit 49 drives the second pressing member 46 in the axial direction L. The pressing drive unit 49 of this embodiment includes a hydraulic chamber 49A and a hydraulic oil supply unit 49B. The hydraulic chamber 49A is a space for applying hydraulic pressure to the second pressing member 46. In this embodiment, the hydraulic chamber 49A is formed in a space surrounded by the second cylindrical support portion 62, the third cylindrical support portion 63, the first support wall portion 6Ab, and the second pressing member 46. The hydraulic oil supply unit 49B is provided so as to communicate with the hydraulic chamber 49A, and supplies oil (hydraulic oil) to the hydraulic chamber 49A. The hydraulic chamber 49A and the hydraulic oil supply unit 49B are formed in the case 6 (the first case portion 6A in this example).

[0059] When oil of a predetermined hydraulic pressure is supplied from the hydraulic oil supply unit 49B to the hydraulic chamber 49A, the second pressing member 46 moves to the second axial side L2 by the hydraulic pressure. Then, the second pressing member 46 presses the first pressing member 45 from the first axial side L1 while being rotatable relative to the first pressing member 45 via the thrust bearing 95. As a result, the second pressing member 46 and the first pressing member 45 work together to press the first friction material 43 and the second friction material 44 to the second axial side L2, and the first friction material 43 and the second friction material 44 are pressed against each other.

[0060] The second pressing member 46 is arranged concentrically with the support bearing 93 (first bearing 931 in this example) supporting the end of the shaft member 20 on the first axial side L1, and is arranged outside the support bearing 93 in the radial direction R. The second pressing member 46 is arranged with the input bearing 92 supporting the end of the input member 10 on the first axial side L1, with their outer peripheries facing each other. Thus, the second pressing member 46 is arranged outside the support bearing 93 in the radial direction R, and a part of the second pressing member 46 in the circumferential direction is arranged between the input bearing 92 and the support bearing 93. In this embodiment, the arrangement area D3 of the second pressing member 46 in the axial direction L overlaps with both the arrangement area D1 of the input bearing 92 in the axial direction L and the arrangement area D2 of the support bearing 93 in the axial direction L. The term "overlap" is a concept that includes not only the case where the two parts overlap in their entirety, but also the case where they partially overlap each other.

[0061] In this way, the second pressing member 46 is located radially outward from the support bearing 93, and a portion of it in the circumferential direction is located between the input bearing 92 and the support bearing 93, and the arrangement area D3 in the axial direction L of the second pressing member 46 overlaps with both the arrangement area D1 in the axial direction L of the input bearing 92 and the arrangement area D2 in the axial direction L of the support bearing 93.

[0062] According to this configuration, the arrangement area D3 in the axial direction L of the second pressing member 46 overlaps with both the arrangement area D1 in the axial direction L of the input bearing 92 and the arrangement area D2 in the axial direction L of the support bearing 93, making it easy to keep the axial dimension of the transmission 1 small. While the friction engagement device 40 is configured to include the first pressing member 45 and the second pressing member 46 to improve controllability, the second pressing member 46 can be disposed by utilizing the space between the input bearing 92 and the support bearing 93, thereby preventing the device from becoming large in size as a whole.

[0063] Note that, while the input bearing 92 and the support bearing 93 are fixed to the case 6, the second pressing member 46 is movable in the axial direction L. For this reason, the arrangement area D3 of the second pressing member 46 in the axial direction L represents the maximum movable range of the second pressing member 46 in the axial direction L. In this embodiment, the arrangement area D3 of the second pressing member 46 in the axial direction L entirely overlaps with the arrangement area D1 of the input bearing 92 in the axial direction L. In addition, the arrangement area D3 of the second pressing member 46 in the axial direction L overlaps with the arrangement area D2 of the support bearing 93 in the axial direction L except for a part of the first axial side L1.

[0064] The input bearing 92 is disposed such that a portion of its circumferential direction is located inward in the radial direction R from the second friction material support portion 42A. As shown in Fig. 5, the input bearing 92 is disposed such that the first friction material 43 and the second friction material 44 overlap with each other when viewed in the axial direction. In this embodiment, the input bearing 92 is disposed such that the outer circumferential portions of the first friction material 43 and the second friction material 44 partially overlap with each other.

[0065] As described above, the vehicle drive transmission device 100 includes the first gear 25, the second gear 3A, the third gear 22, the fourth gear 24, the fifth gear 12, and the sixth gear 14. The first gear 25 and the second gear 3A, which mesh with each other, are configured as helical gears. The third gear 22 and the fifth gear 12, which mesh with each other, are configured as helical gears. The fourth gear 24 and the sixth gear 14, which mesh with each other, are configured as helical gears.

[0066] As described above, each gear is made up of a helical gear, and therefore, when a pair of meshing gears transmits a driving force, an axial load is applied to the meshing portion of the pair of gears, which presses the pair of gears against each other in the opposite direction in the axial direction L.

[0067] As for the first gear 25 and the second gear 3A, as shown in FIG. 2, the helical direction of the first gear 25 and the helical direction of the second gear 3A are set so that the first gear 25 receives an axial load (hereinafter referred to as "first gear load f1") acting from the second axial side L2 toward the first axial side L1 at the meshing portion between the first gear 25 and the second gear 3A. In detail, the helical direction of the first gear 25 and the helical direction of the second gear 3A are set so that the first gear 25 receives the first gear load f1 in a state in which the rotating electric machine 2 generates a driving force in the forward direction of the vehicle. When the first gear 25 receives the first gear load f1, an axial load (hereinafter referred to as "second axial load F2") in the same direction as the first gear 25, that is, an axial load in the same direction as the first gear load f1, that is, from the second axial side L2 toward the first axial side L1, acts on the shaft member 20. In addition, the rotation direction of each component when the wheel W is rotating in a direction that moves the vehicle forward is defined as the forward direction, and the driving force in the same direction as the forward direction is the "driving force in the forward direction of the vehicle."

[0068] In this way, by forming the first gear 25 and the second gear 3A as helical gears, it is possible to reduce noise due to tooth contact sound generated when the first gear 25 and the second gear 3A mesh. On the other hand, in a state in which the rotating electric machine 2 generates a driving force in the forward direction of the vehicle, the second axial load F2 always acts on the shaft member 20, and the first bearing 931 (support bearing 93) configured to restrict movement toward the first axial side L1 supports the second axial load F2. Naturally, in a state in which the rotating electric machine 2 generates a driving force in the backward direction of the vehicle, the second axial load F2 becomes a load toward the second axial side L2, and the load is supported by the second bearing 932 (support bearing 93). However, in general, the period in which the vehicle moves forward is longer than the period in which the vehicle moves backward. Therefore, the rotating electric machine 2 also generates a driving force in the forward direction of the vehicle at a higher rate than the driving force in the backward direction. Therefore, the load caused by supporting the second axial load F2 is greater on the first bearing 931 than on the second bearing 932, which causes accelerated wear, etc. of the first bearing 931 compared to the second bearing 932.

[0069] As described above, in the vehicle drive transmission device 100 according to the present disclosure, the piston portion P of the friction engagement device 40 is configured to press the first friction material 43 and the second friction material 44 toward the axial second side L2. As shown in FIG. 3 and FIG. 4, when the piston portion P presses the first friction material 43 and the second friction material 44, an axial load (hereinafter referred to as a "pressing load fp") acts on the first support member 41 having the axial support portion 41D from the axial first side L1 to the axial second side L2. As described above, the first support member 41 abuts against the surface of the intermediate step portion 28 facing the axial first side L1 from the axial first side L1. Therefore, when the first support member 41 receives the pressing load fp acting toward the axial second side L2, an axial load (hereinafter referred to as a "first axial load F1") acts on the shaft member 20 from the axial first side L1 to the axial second side L2. That is, according to the above configuration, the first axial load F1 directed in the opposite direction to the second axial load F2 generated on the shaft member 20 by the meshing of the first gear 25 and the second gear 3A can be applied to the shaft member 20 by the pressing of the piston portion P. Therefore, according to this configuration, in a state in which the piston portion P presses the pair of friction members (the first friction material 43 and the second friction material 44), the second axial load F2 acting on the shaft member 20 can be reduced. As a result, the load on the first bearing 931 (support bearing 93) supporting the shaft member 20 can be reduced.

[0070] In this embodiment, the rotation is decelerated between the first gear 25 and the second gear 3A. Therefore, the torque transmitted through the second gear 3A tends to be relatively large, and accordingly, the second axial load F2 received by the first gear 25 and the shaft member 20 tends to be large. Therefore, the second axial load F2 tends to be larger than the pressing load fp by the piston portion P. Moreover, the pressing load fp by the piston portion P does not act when the piston portion P is not pressing the pair of friction members.

[0071] In this embodiment, the helical directions of the third gear 22 and the fifth gear 12 are set so that the third gear 22 receives an axial load acting from the first axial side L1 toward the second axial side L2 at the meshing portion between the third gear 22 and the fifth gear 12. The helical directions of the fourth gear 24 and the sixth gear 14 are set so that the fourth gear 24 receives an axial load acting from the first axial side L1 toward the second axial side L2 at the meshing portion between the fourth gear 24 and the sixth gear 14. Hereinafter, the axial load received by the third gear 22 is referred to as a "third gear load f3," and the axial load received by the fourth gear 24 is referred to as a "fourth gear load f4." As described above, the third gear load f3 and the fourth gear load f4 act from the first axial side L1 toward the second axial side L2. In this embodiment, as described above, the third gear 22 and the fourth gear 24 are configured to be selectively connected to the shaft member 20 by the meshing engagement device 30. Therefore, when the third gear 22 is not connected to the shaft member 20 and rotates idly, no driving force is transmitted at the meshing portion between the third gear 22 and the fifth gear 12, and no third gear load f3 acts. Similarly, when the fourth gear 24 is not connected to the shaft member 20 and rotates idly, no driving force is transmitted at the meshing portion between the fourth gear 24 and the sixth gear 14, and no fourth gear load f4 acts.

[0072] As shown in FIG. 3, the third gear load f3 acts on the third gear forming member 21 via the third gear 22. The third gear forming member 21 is supported rotatably relative to the shaft member 20 via a bearing (a needle roller bearing in this example) and is supported immovably in the axial direction L relative to the shaft member 20. Therefore, in a state in which the meshing engagement device 30 connects the third gear 22 to the shaft member 20 and a driving force is transmitted at the meshing portion between the third gear 22 and the fifth gear 12, the third gear load f3 is transmitted from the third gear forming member 21 to the shaft member 20. Therefore, in addition to the pressing load fp by the piston portion P described above, the shaft member 20 is also subjected to the first axial load F1 from the first axial side L1 to the second axial side L2 by the third gear load f3.

[0073] The fourth gear load f4 acts on the fourth gear forming member 23 via the fourth gear 24. The fourth gear forming member 23 is supported rotatably relative to the shaft member 20 via a bearing (a needle roller bearing in this example) and is supported immovably in the axial direction L relative to the shaft member 20. Therefore, in a state in which the meshing engagement device 30 connects the fourth gear 24 to the shaft member 20 and the driving force is transmitted at the meshing portion between the fourth gear 24 and the sixth gear 14, the fourth gear load f4 is transmitted from the fourth gear forming member 23 to the shaft member 20. Note that, in this embodiment, the fourth gear 24 is configured to be connected to the shaft member 20 also when the friction engagement device 40 is in an engaged state. Therefore, even in a state in which the friction engagement device 40 connects the fourth gear 24 to the shaft member 20, the fourth gear load f4 is transmitted from the fourth gear forming member 23 to the shaft member 20. In this way, in addition to the pressing load fp by the piston portion P described above, the first axial load F1 from the first axial side L1 to the second axial side L2 is also applied to the shaft member 20 by the fourth gear load f4. As described above, the meshing engagement device 30 selectively connects either the third gear 22 or the fourth gear 24 to the shaft member 20. The frictional engagement device 40 also connects the fourth gear 24 to the shaft member 20 depending on the engagement state. Therefore, in this embodiment, depending on the engagement state between the meshing engagement device 30 and the frictional engagement device 40, a state in which only the third gear load f3 acts on the shaft member 20, a state in which only the fourth gear load f4 acts on the shaft member 20, and a state in which both the third gear load f3 and the fourth gear load f4 act on the shaft member 20 may occur.

[0074] According to the above configuration, due to the meshing between the third gear 22 and the fifth gear 12, and the meshing between the fourth gear 24 and the sixth gear 14, the first axial load F1 directed in the opposite direction to the second axial load F2 generated by the meshing between the first gear 25 and the second gear 3A can be applied to the shaft member 20. Therefore, according to this configuration, the second axial load F2 acting on the shaft member 20 can be reduced, and as a result, the load acting on the first bearing 931 (support bearing 93) supporting the shaft member 20 can be reduced.

[0075] In this embodiment, the pressing load fp received by the first support member 41 through the piston portion P, the third gear load f3 received by the third gear 22, and the fourth gear load f4 received by the fourth gear 24 act on the shaft member 20 as a first axial load F1 directed from the first axial side L1 to the second axial side L2. In other words, the first axial load F1 is the resultant force of the pressing load fp, the third gear load f3, and the fourth gear load f4 (F1=fp+f3+f4). However, as described above, the pressing load fp, the third gear load f3, and the fourth gear load f4 may be zero or close to zero depending on their respective states. From this perspective, the first axial load F1 can also be said to be at least a part of the pressing load fp, the third gear load f3, and the fourth gear load f4.

[0076] In this embodiment, the maximum value (F1max) of the first axial load F1 is set to be equal to or greater than the maximum value (F2max) of the second axial load F2 (F1max≧F2max). As described above, the pressing load fp, the third gear load f3, and the fourth gear load f4 constituting the first axial load F1 change according to their respective states. In particular, the pressing load fp occurs only when the piston portion P presses the pair of friction members. On the other hand, the first gear load f1 constituting the second axial load F2 always acts on the shaft member 20 when the wheels W are driven. In addition, in this embodiment, the rotation is decelerated and the driving force is amplified as it moves from the rotating electric machine 2 to the wheel W along the transmission path of the driving force, so that the first gear load f1 is larger than the third gear load f3 and the fourth gear load f4. For these reasons, in the configuration of this embodiment, the period during which the second axial load F2 is larger than the first axial load F1 is more likely to be longer than the period during which the opposite situation occurs. Therefore, by setting the maximum value of the first axial load F1 to be equal to or greater than the maximum value of the second axial load F2 (F1max≧F2max), it is possible to prevent the second axial load F2 from acting on the first bearing 931 (support bearing 93) at least in a state in which the first axial load F1 is larger than the second axial load F2. Therefore, it is possible to further reduce the load acting on the first bearing 931 (support bearing 93).

[0077] The maximum value (F1max) of the first axial load F1 is set by adjusting at least one of the pressing load fp, the third gear load f3, and the fourth gear load f4. The pressing load fp is adjusted, for example, by increasing or decreasing the pressing force of the piston portion P. The third gear load f3 is adjusted, for example, by changing the inclination angles of the helices of the third gear 22 and the fifth gear 12, or by changing the gear ratio thereof. The fourth gear load f4 is adjusted, for example, by changing the inclination angles of the helices of the fourth gear 24 and the sixth gear 14, or by changing the gear ratio thereof.

[0078] As described above, in this embodiment, the support bearing 93 includes a first bearing 931 arranged on a first axial side L1 relative to the first gear 25, and a second bearing 932 arranged on a second axial side L2 relative to the first gear 25, and the first bearing 931 is configured to restrict movement of the shaft member 20 toward the first axial side L1, and the second bearing 932 is configured to restrict movement of the shaft member 20 toward the second axial side L2.

[0079] According to this configuration, the first bearing 931 and the second bearing 932 can share and support the axial load (first axial load F1 and second axial load F2) acting on the shaft member 20. Also, in this configuration, the first gear 25 receives the axial load (first gear load f1) from the second gear 3A, and the axial load (second axial load F2) acting on the shaft member 20 is supported by the first bearing 931. However, as described above, the axial load (second axial load F2) toward the first axial side L1 can be reduced by the pressing force of the piston part P. Therefore, it is easy to keep the difference between the axial loads (first axial load F1 and second axial load F2) acting on the first bearing 931 and the second bearing 932 small. Also, because this difference can be easily kept small, it is possible to reduce the need to use a bearing having higher durability than the second bearing 932 as the first bearing 931. Therefore, for example, the same bearing can be used for the first bearing 931 and the second bearing 932. This reduces the number of types of parts in the vehicle drive transmission device 100, contributing to cost reduction.

[0080] As described above, in this embodiment, the friction engagement device 40 includes a first support member 41 (inner support member) that supports one of the pair of friction members (first friction material 43) from the inside in the radial direction R, and a second support member 42 (outer support member) that supports the other of the pair of friction members (second friction material 44) from the outside in the radial direction R. The first support member 41 includes an axial support portion 41D that supports the pair of friction members from the opposite side in the axial direction L to the piston portion P, sandwiching the pair of friction members, and is supported by the shaft member 20 in a state in which movement toward the second axial side L2 relative to the shaft member 20 is restricted.

[0081] According to this configuration, the axial load (pressing load fp) acting on the pair of friction members due to the pressing of the piston portion P can be supported by the axial support portion 41D of the first support member 41. The friction engagement device 40 including the first support member 41 is supported by the shaft member 20. Therefore, according to this configuration, the pressing force of the piston portion P can be appropriately transmitted to the shaft member 20 as the axial load (first axial load F1).

[0082] As described above, this embodiment includes an input member 10 drivingly connected to a rotating electric machine 2 (driving force source), a pair of output members 4 each drivingly connected to a wheel W, a differential gear mechanism 3 that distributes the rotation of the second gear 3A to the pair of output members 4, and a meshing engagement device 30, in which the first gear 25 is supported so as to rotate integrally with the shaft member 20, the second gear 3A is a differential input gear, the third gear 22 and the fourth gear 24 are supported so as to be rotatable relative to the shaft member 20, the fifth gear 12 and the sixth gear 14 are supported by the input member 10 so as to rotate integrally with the input member 10, the meshing engagement device 30 is configured to selectively connect either the third gear 22 or the fourth gear 24 to the shaft member 20, and the friction engagement device 40 is configured to selectively connect the fourth gear 24 to the shaft member 20.

[0083] According to this configuration, two gears with different gear ratios can be formed, and the rotation transmitted from the rotating electric machine 2 (driving force source) can be changed in speed and transmitted to the pair of wheels W at either of these two gears. In addition, the two gears can be selectively formed by the meshing engagement device 30, and a gradual shift from the gear using the third gear 22 to the gear using the fourth gear 24 can be made by shifting the friction engagement device 40 from a released state to an engaged state. Therefore, according to this configuration, a smooth shift between gears can be made.

[0084] Other embodiments Next, other embodiments of the vehicle drive transmission device 100 will be described.

[0085] (1) In the above embodiment, an example has been described in which the vehicle drive transmission device 100 includes the piston portion P, the third gear 22 meshing with the fifth gear 12, and the fourth gear 24 meshing with the sixth gear 14 as a configuration that generates the first axial load F1. However, the present invention is not limited to such an example, and the configuration that generates the first axial load F1 may be only the piston portion P. The configuration that generates the first axial load F1 may be the piston portion P and a gear equivalent to either one of the third gear 22 and the fourth gear 24.

[0086] (2) In the above embodiment, an example in which the first gear 25 is formed integrally with the shaft member 20 has been described. However, the present invention is not limited to this example, and the first gear 25 may be a member separate from the shaft member 20 as long as the first gear 25 is supported by the shaft member 20 in a state in which the relative movement in at least the axial direction L is restricted. In this case, for example, a step portion such as the above-mentioned first step portion 26 may be formed on the shaft member 20, and the movement of the first gear 25 in the axial direction L may be restricted by this step portion. On the other hand, the circumferential movement of the first gear 25 with respect to the shaft member 20 may be restricted by spline engagement or the like, or the first gear 25 may be supported via a bearing or the like so as to be relatively rotatable and selectively coupled by an engagement device.

[0087] (3) In the above embodiment, an example has been described in which the entire arrangement region D3 of the second pressing member 46 in the axial direction L is included in the arrangement region D1 of the input bearing 92 in the axial direction L and partially overlaps with the arrangement region D2 of the support bearing 93 in the axial direction L. However, without being limited to such an example, for example, the entire arrangement region D3 of the second pressing member 46 in the axial direction L may be included in both the arrangement region D1 of the input bearing 92 in the axial direction L and the arrangement region D2 of the support bearing 93 in the axial direction L. Alternatively, the arrangement region D3 of the second pressing member 46 in the axial direction L may partially overlap with each of the arrangement region D1 of the input bearing 92 in the axial direction L and the arrangement region D2 of the support bearing 93 in the axial direction L.

[0088] (4) In the above embodiment, an example has been described in which a return spring formed using a coil spring is used as the biasing member 48. However, the present invention is not limited to this example, and for example, a leaf spring or the like may be used as the biasing member 48.

[0089] (5) In the above embodiment, an example has been described in which the pressing drive unit 49 includes the hydraulic chamber 49A and the hydraulic oil supply unit 49B. However, the present invention is not limited to this example, and for example, the pressing drive unit 49 may include an electric actuator or the like.

[0090] (6) In the above embodiment, the rotating electric machine 2 is exemplified as the driving force source. However, without being limited to this example, the driving force source may be an internal combustion engine, or a combination of an internal combustion engine and a rotating electric machine 2. In other words, the technology disclosed herein can also be applied to other types of vehicle drive transmission devices, such as a so-called engine vehicle that uses an internal combustion engine as a driving source for the wheels, or a hybrid vehicle that uses both an internal combustion engine and a rotating electric machine 2.

[0091] (7) The configurations disclosed in the above-mentioned embodiments (including the above-mentioned embodiments and other embodiments; the same applies below) can be applied in combination with configurations disclosed in other embodiments, as long as no contradiction occurs. As for other configurations, the embodiments disclosed in this specification are illustrative in all respects and can be appropriately modified within the scope of the present disclosure. [Industrial Applicability]

[0092] The technology disclosed herein can be used in a vehicle drive transmission device. [Explanation of symbols]

[0093] 100: Vehicle drive transmission device, 3: Differential gear mechanism, 3A: Second gear, 4: Output member, 10: Input member, 12: Fifth gear, 14: Sixth gear, 20: Shaft member, 22: Third gear, 24: Fourth gear, 25: First gear, 30: Meshing engagement device, 40: Friction engagement device, 41D: Axial support portion, 93: Support bearing, 931: First bearing, 932: Second bearing, P: Piston portion, L: Axial direction, L1: Axial first side, L2: Axial second side, R: Radial direction, W: Wheel

Claims

1. a first gear which is a helical gear supported by a shaft member; a second gear which is a helical gear meshing with the first gear; a support bearing that rotatably supports the shaft member; a friction engagement device supported by the shaft member, A direction along the rotation axis of the shaft member is defined as an axial direction, one side in the axial direction is defined as an axial first side, and the other side in the axial direction is defined as an axial second side, The friction engagement device includes a pair of friction members supported so as to be rotatable relative to one another, and a piston portion that presses the pair of friction members in the axial direction so as to press them against each other, a helical direction of the first gear and a helical direction of the second gear are set so that the first gear receives an axial load acting from the second axial side toward the first axial side at a meshing portion between the first gear and the second gear, The piston portion is configured to press the pair of friction members toward the second axial side, a third gear which is a helical gear supported by the shaft member; A fifth gear which is a helical gear meshing with the third gear, a helical direction of the third gear and a helical direction of the fifth gear are set so that the third gear receives an axial load acting from the first axial side toward the second axial side at the meshing portion between the third gear and the fifth gear.

2. the support bearing includes a first bearing arranged on a first axial side with respect to the first gear, and a second bearing arranged on a second axial side with respect to the first gear, The first bearing is configured to restrict movement of the shaft member toward the first side in the axial direction, The vehicle drive transmission device according to claim 1 , wherein the second bearing is configured to restrict movement of the shaft member toward the second side in the axial direction.

3. A direction perpendicular to the rotation axis of the shaft member is defined as a radial direction, the friction engagement device includes an inner support member that supports one of the pair of friction members from an inner side in the radial direction, and an outer support member that supports the other of the pair of friction members from an outer side in the radial direction, 3. The vehicle drive transmission device according to claim 1, wherein the inner support member includes an axial support portion that supports the pair of friction members from the axial opposite side to the piston portion, with the pair of friction members sandwiched therebetween, and is supported by the shaft member in a state in which movement toward the second axial side relative to the shaft member is restricted.

4. a fourth gear which is a helical gear supported by the shaft member; a sixth gear which is a helical gear meshing with the fourth gear, 4. The vehicle drive transmission device according to claim 1, wherein the helical direction of the fourth gear and the helical direction of the sixth gear are set so that the fourth gear receives an axial load acting from the first axial side toward the second axial side at the meshing portion between the fourth gear and the sixth gear.

5. an input member drivingly connected to a source of drive force; A pair of output members each drivingly connected to a wheel; a differential gear mechanism that distributes rotation of a differential input gear to a pair of said output members; and a meshing engagement device, the first gear is supported so as to rotate integrally with the shaft member, the second gear is the differential input gear, the third gear and the fourth gear are supported to be rotatable relative to the shaft member, the fifth gear and the sixth gear are supported by the input member so as to rotate integrally with the input member, the meshing engagement device is configured to selectively connect one of the third gear and the fourth gear to the shaft member; 5. The vehicle drive transmission device according to claim 4, wherein the friction engagement device is configured to selectively connect the fourth gear to the shaft member.

6. A vehicle drive transmission device as described in any one of claims 1 to 5, wherein the third gear is arranged on the first axial side of the first gear.

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