Vehicle drive unit

Abstract

To provide a vehicle drive device capable of minimizing distortion generated in a stator support section due to thrust force transmitted through a support member that supports a helical gear in an axial direction.SOLUTION: A rotating electric machine 1, a transmission 2, and a differential gear device 3 are arranged coaxially. The transmission 2 includes a first helical gear HG1 and a second helical gear HG2, which meshes with the first helical gear HG1. A case 10 includes: a first case member 6, which is provided with a stator support section 61 that supports the stator 11 of the rotating electric machine 1; a second case member 7, which is a separate component from the first case member 6 and forms a gear chamber C2 that houses the transmission 2 and the differential gear device 3; and a support member 8, which supports the first helical gear HG1 in the axial direction L. The support member 8 rotatably supports a rotor 12 of the rotating electric machine 1 via a rotor bearing B1 and is fixed to the second case member 7.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vehicle drive device that includes a rotating electric machine, a transmission that changes the speed of rotation transmitted from the rotor of the rotating electric machine, a differential gear device that distributes the driving force from the rotating electric machine transmitted via the transmission to a pair of wheels, and a case that houses them. [Background technology]

[0002] An example of such a vehicle drive device is disclosed in the following Patent Document 1. In the following description of the background art, the reference numerals in Patent Document 1 will be cited in parentheses.

[0003] In the vehicle drive device (100) of Patent Document 1, the case (1) includes a first case member (11) having a stator support portion that supports a stator (24) of a rotating electric machine (2), and a second case member (12) that is configured as a separate member from the first case member and forms a gear chamber that houses a transmission (3) and a differential gear device (4). The first case member (11) and the second case member (12) are joined to each other in the axial direction (L). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-74205 Summary of the Invention [Problem to be solved by the invention]

[0005] In the vehicle drive device (100) of Patent Document 1, the transmission (3) includes a first planetary gear mechanism (31) and a second planetary gear mechanism (32), each of which is a single-pinion planetary gear mechanism. Each gear of the first planetary gear mechanism (31) and the second planetary gear mechanism (32) is a helical gear.

[0006] The case (1) further includes a support member (14) that supports the first ring gear (R31) of the first planetary gear mechanism (31) and the second ring gear (R32) of the second planetary gear mechanism (32) in the axial direction (L). The support member (14) is fixed to a first case member (11) that includes a stator support portion.

[0007] In the above-described configuration, a thrust force acting on the first ring gear (R31) due to meshing with the first pinion gear of the first planetary gear mechanism (31) and a thrust force acting on the second ring gear (R32) due to meshing with the second pinion gear of the second planetary gear mechanism (32) are transmitted to the first case portion (11) via the support member (14). As a result, the stator support portion of the first case portion (11) is distorted by the thrust force transmitted via the support member (14), which in turn may cause the stator supported by the stator support portion to deform, resulting in a deterioration in performance of the rotating electric machine.

[0008] Therefore, it is desirable to realize a vehicle drive device that can minimize distortion that occurs in a stator support portion due to thrust forces transmitted via a support member that supports a helical gear in the axial direction. [Means for solving the problem]

[0009] In view of the above, the characteristic configuration of the vehicle drive device is as follows: a rotating electric machine including a stator and a rotor; a transmission that changes the speed of the rotation transmitted from the rotor; a differential gear device that distributes driving force from the rotating electric machine transmitted via the transmission to a pair of wheels provided on the vehicle; a case that houses the rotating electric machine, the transmission, and the differential gear device, the rotating electric machine, the transmission, and the differential gear device are arranged coaxially, the transmission includes a first helical gear and a second helical gear that meshes with the first helical gear, The direction along the rotation axis of the rotor is defined as the axial direction, the case includes a first case member having a stator support portion that supports the stator, a second case member that is configured as a separate member from the first case member and that forms a gear chamber in which the transmission and the differential gear device are housed, and a support member that supports the first helical gear in the axial direction, The support member rotatably supports the rotor via a rotor bearing, and is fixed to the second case member.

[0010] According to this characteristic configuration, the thrust force acting on the first helical gear due to meshing with the second helical gear is transmitted to the second case member via the support member that supports the first helical gear in the axial direction, and the first helical gear is supported by the support member and the second case member. Furthermore, because the first case member and the second case member are separate members, the thrust force transmitted to the second case member is less likely to be transmitted to the first case member. Therefore, distortion of the stator support member caused by the thrust force transmitted via the support member that supports the first helical gear in the axial direction can be minimized. As a result, it is possible to avoid a deterioration in the performance of the rotating electric machine due to deformation of the stator supported by the stator support member. Furthermore, according to this characteristic configuration, the support member not only supports the first helical gear in the axial direction, but also rotatably supports the rotor via the rotor bearing. In this way, the first helical gear and the rotor bearing are supported by a single support member. This allows the vehicle drive device to be more compact than in a configuration in which the rotor bearing is supported by a member separate from the support member. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a cross-sectional view of a vehicle drive device according to an embodiment taken along an axial direction; [Figure 2] 1 is a skeleton diagram of a vehicle drive device according to an embodiment; [Figure 3] FIG. 1 is a partially enlarged cross-sectional view of a vehicle drive device according to an embodiment, taken along an axial direction; DETAILED DESCRIPTION OF THE INVENTION

[0012] A vehicle drive device 100 according to an embodiment will be described below with reference to the drawings. As shown in Fig. 1 and Fig. 2, the vehicle drive device 100 includes a rotating electric machine 1 including a stator 11 and a rotor 12, a transmission 2 that changes the speed of rotation transmitted from the rotor 12, a differential gear device 3 that distributes the driving force transmitted from the rotating electric machine 1 via the transmission 2 to a pair of wheels W (see Fig. 2) of a vehicle, and a case 10 that houses them.

[0013] In the following description, the direction along the rotational axis of the rotor 12 (see the dashed line in FIG. 1) is referred to as the "axial direction L." One side of the axial direction L is referred to as the "first axial side L1," and the other side of the axial direction L is referred to as the "second axial side L2." The direction perpendicular to the rotational axis of the rotor 12 is referred to as the "radial direction R." In the radial direction R, the side of the rotational axis of the rotor 12 is referred to as the "radial inner side R1," and the opposite side is referred to as the "radial outer side R2." The direction going around the rotational axis of the rotor 12 is referred to as the "circumferential direction C."

[0014] The rotating electric machine 1, the transmission 2, and the differential gear device 3 are arranged coaxially. In this embodiment, the rotating electric machine 1, the transmission 2, and the differential gear device 3 are arranged in the order shown, from the first axial side L1 to the second axial side L2.

[0015] The rotating electric machine 1 functions as a driving force source for a pair of wheels W (see FIG. 2). The rotating electric machine 1 has a function as a motor (electric motor) that receives a supply of electric power to generate power, and a function as a generator that receives a supply of power to generate electric power. Specifically, the rotating electric machine 1 is electrically connected to an electric storage device (not shown) such as a battery or a capacitor. The rotating electric machine 1 generates driving force by running using the electric power stored in the electric storage device. The rotating electric machine 1 also generates power using the driving force transmitted from the pair of wheels W, thereby charging the electric storage device.

[0016] The stator 11 of the rotating electric machine 1 includes a cylindrical stator core 11a. The stator core 11a is fixed to the case 10. The rotor 12 of the rotating electric machine 1 includes a cylindrical rotor core 12a. The rotor core 12a is rotatably supported relative to the stator core 11a. In this embodiment, the rotor 12 further includes a rotor shaft 12b connected to the rotor core 12a so as to rotate integrally with the rotor core 12a. The rotor shaft 12b is formed in a cylindrical shape coaxial with the rotor core 12a.

[0017] In this embodiment, the rotating electric machine 1 is an inner rotor type rotating electric machine. Therefore, the rotor core 12a is arranged radially inward R1 with respect to the stator core 11a. The rotor shaft 12b is also arranged radially inward R1 with respect to the rotor core 12a.

[0018] In this embodiment, the rotating electric machine 1 is a rotating field type rotating electric machine. Therefore, the stator 11 further includes a stator coil 11b. In this embodiment, the stator coil 11b is wound around the stator core 11a so as to form a first coil end portion 11c that protrudes toward a first axial side L1 relative to the stator core 11a and a second coil end portion 11d that protrudes toward a second axial side L2 relative to the stator core 11a. Although not shown, a permanent magnet is provided in the rotor core 12a.

[0019] 3, in this embodiment, the transmission 2 includes a planetary gear mechanism 21. In this embodiment, the planetary gear mechanism 21 includes a sun gear SG, a carrier CR, a first ring gear RG1, and a second ring gear RG2.

[0020] The sun gear SG is connected to the rotor 12 so as to rotate integrally with the rotor 12. In the illustrated example, the sun gear SG is connected to the rotor shaft 12b by welding or the like so as to rotate integrally with the rotor shaft 12b.

[0021] In this embodiment, the carrier CR is configured to rotatably support a first pinion gear PG1 and a second pinion gear PG2. The first pinion gear PG1 and the second pinion gear PG2 are connected to each other so as to rotate integrally with each other. The first pinion gear PG1 meshes with the sun gear SG and the first ring gear RG1. The second pinion gear PG2 meshes with the second ring gear RG2. The second pinion gear PG2 is formed to have a smaller diameter than the first pinion gear PG1.

[0022] The first ring gear RG1 is connected to the case 10. The second ring gear RG2 is disposed on the second axial side L2 relative to the first ring gear RG1. The second ring gear RG2 is connected to the input element of the differential gear device 3 so as to rotate integrally with the input element. The manner in which these ring gears RG1 and RG2 are connected will be described in detail later.

[0023] Each of the sun gear SG, first pinion gear PG1, second pinion gear PG2, first ring gear RG1, and second ring gear RG2 is a helical gear. Here, a helical gear is a gear whose tooth trace is inclined with respect to the rotation axis. The first ring gear RG1 corresponds to the "first helical gear HG1." The first pinion gear PG1 corresponds to the "second helical gear HG2."

[0024] Thus, in this embodiment, the rotation of the rotor 12 is reduced in speed by the planetary gear mechanism 21 and transmitted to the differential gear device 3. That is, in this embodiment, the transmission 2 functions as a reducer that reduces the rotation transmitted from the rotor 12 at a constant reduction ratio.

[0025] In this embodiment, the differential gear device 3 includes a differential case 31, a shaft member 32, a pinion gear 33, a first side gear 34, and a second side gear 35. Here, the pinion gear 33, the first side gear 34, and the second side gear 35 are all bevel gears.

[0026] The differential case 31 is formed to accommodate the pinion gear 33, the first side gear 34, and the second side gear 35. The differential case 31 is an input element of the differential gear device 3. Therefore, the differential case 31 is connected to the second ring gear RG2 of the planetary gear mechanism 21 so as to rotate integrally with the second ring gear RG2. In the illustrated example, the differential case 31 is connected to the second ring gear RG2 by welding so as to rotate integrally with the second ring gear RG2.

[0027] The shaft members 32 are arranged to extend along the radial direction R. The shaft members 32 are supported by the differential case 31 so as to rotate integrally with the differential case 31. In this embodiment, a configuration is adopted in which multiple shaft members 32 are distributed and arranged in the circumferential direction C along the radial direction R (for example, a configuration in which four shaft members 32 are arranged in a cross shape when viewed in the axial direction along the axial direction L).

[0028] The pinion gear 33 is rotatably supported by the shaft member 32. The pinion gear 33 is configured to be rotatable (spin) about the shaft member 32 and to be rotatable (revolve) about the rotation axis of the differential case 31. In this embodiment, the pinion gear 33 is attached to each of the multiple shaft members 32.

[0029] The first side gear 34 and the second side gear 35 mesh with the pinion gear 33. The first side gear 34 and the second side gear 35 are arranged to rotate about the rotation axis of the differential case 31. The first side gear 34 is arranged on a first axial side L1 with respect to the shaft member 32. The second side gear 35 is arranged on a second axial side L2 with respect to the shaft member 32.

[0030] In this embodiment, the first side gear 34 is connected to rotate integrally with a first drive shaft DS1, which is drivingly connected to a wheel W on a first axial side L1, via an output shaft member 4 extending along the axial direction L. In the example shown in the figure, the output shaft member 4 is inserted from the first axial side L1 to the radially inner side R1 of the first side gear 34, and they are connected to each other by spline engagement.

[0031] The output shaft member 4 is arranged to penetrate the radially inner side R1 of the transmission 2 and the rotating electric machine 1 in the axial direction L. In this embodiment, the output shaft member 4 is arranged to penetrate the radially inner side R1 of the sun gear SG of the planetary gear mechanism 21 and the rotor shaft 12b of the rotating electric machine 1 in the axial direction L.

[0032] In this embodiment, the second side gear 35 is connected to a second drive shaft DS2 that is drivingly connected to a wheel W on the second axial side L2 so as to rotate integrally with the second side gear 35. In the illustrated example, the second drive shaft DS2 is inserted from the second axial side L2 to the radially inner side R1 of the second side gear 35, and they are connected to each other by spline engagement.

[0033] 1, the case 10 includes a first case member 6, a second case member 7, and a support member 8. In this embodiment, the case 10 further includes a cover member 9.

[0034] The first case member 6 is a member that forms a rotary electric machine chamber C1 that accommodates the rotary electric machine 1. The first case member 6 includes a stator support portion 61 that supports the stator 11 of the rotary electric machine 1.

[0035] In this embodiment, the first case member 6 further includes a first peripheral wall portion 62. The first peripheral wall portion 62 is formed to surround the rotating electric machine chamber C1 in the circumferential direction C. In this embodiment, the first peripheral wall portion 62 is formed in a cylindrical shape that covers the radial outside R2 of the stator core 11a. Also, in this embodiment, the stator support portion 61 is formed integrally with the first peripheral wall portion 62. The stator core 11a is fixed to the stator support portion 61. Note that, in this embodiment, the first peripheral wall portion 62 does not cover the radial outside R2 of the first coil end portion 11c and the second coil end portion 11d of the rotating electric machine 1. In other words, in this embodiment, the first case member 6 is configured to form a part of the rotating electric machine chamber C1.

[0036] The second case member 7 is a member that forms a gear chamber C2 that houses the transmission 2 and the differential gear device 3. The second case member 7 is configured as a separate member from the first case member 6. In this embodiment, the second case member 7 includes a second peripheral wall portion 71 and a first side wall portion 72.

[0037] The second circumferential wall portion 71 is formed to surround the gear chamber C2 in the circumferential direction C. In this embodiment, the second circumferential wall portion 71 is formed in a cylindrical shape that covers the radial outside R2 of the transmission 2 and the differential gear device 3. The second circumferential wall portion 71 is formed to overlap with the entire transmission 2 and the differential gear device 3 when viewed in the radial direction R. In other words, in this embodiment, the entire transmission 2 and the differential gear device 3 are housed in the second case member 7. Note that with regard to the arrangement of two elements, "overlapping when viewed in a specific direction" means that when an imaginary line parallel to the line of sight is moved in each direction perpendicular to the imaginary line, there is at least a region where the imaginary line intersects with both of the two elements.

[0038] In addition, in this embodiment, the second peripheral wall portion 71 is formed so as to cover the radially outer side R2 of the second coil end portion 11d of the rotating electric machine 1. That is, in this embodiment, the second case member 7 is configured so as to form part of the rotating electric machine chamber C1 in addition to the gear chamber C2.

[0039] The first side wall portion 72 is formed to cover the second axial side L2 of the gear chamber C2. In this embodiment, the first side wall portion 72 is formed integrally with the second axial side wall portion 71 so as to close the opening of the second axial side L2 of the second axial side wall portion 71. A through hole is formed in the first side wall portion 72 so as to pass through in the axial direction L and through which a connecting portion of the second side gear 35 to the second drive shaft DS2 is inserted.

[0040] The cover member 9 is configured as a separate member from the first case member 6 and the second case member 7. In this embodiment, the cover member 9 includes a third peripheral wall portion 91 and a second side wall portion 92.

[0041] The third peripheral wall portion 91 is formed to surround the rotating electric machine chamber C1. In this embodiment, the third peripheral wall portion 91 is formed in a cylindrical shape that covers the radially outer side R2 of the first coil end portion 11c of the rotating electric machine 1. In other words, in this embodiment, the cover member 9 is configured to form a part of the rotating electric machine chamber C1.

[0042] The second side wall portion 92 is formed to cover the first axial side L1 of the rotating electrical machine chamber C1. In this embodiment, the second side wall portion 92 is formed integrally with the third circumferential wall portion 91 to close an opening of the third circumferential wall portion 91 on the first axial side L1. The second side wall portion 92 rotatably supports, via a second bearing B2, a portion of the rotor shaft 12b that protrudes from the rotor core 12a toward the first axial side L1. In this embodiment, the second side wall portion 92 is formed with a through hole that penetrates in the axial direction L and through which a coupling portion of the output shaft member 4 to the first drive shaft DS1 is inserted. The second side wall portion 92 rotatably supports, via a third bearing B3, a coupling portion of the output shaft member 4 to the first drive shaft DS1.

[0043] In this embodiment, the first case member 6 is joined to the second case member 7 from the first axial side L1. In other words, in the axial direction L, the side on which the first case member 6 is arranged relative to the second case member 7 is the first axial side L1. In this way, in this embodiment, the first case member 6 and the second case member 7 are joined to each other in the axial direction L. In the example shown in the figure, the first case member 6 and the second case member 7 are joined so that the first circumferential wall portion 62 and the second circumferential wall portion 71 abut against each other in the axial direction L.

[0044] In this embodiment, the cover member 9 is joined to the first case member 6 from the first axial side L1. In the illustrated example, the cover member 9 and the first case member 6 are joined so that the third peripheral wall portion 91 and the first peripheral wall portion 62 abut against each other in the axial direction L.

[0045] As shown in FIG. 3, the support member 8 is configured to support the first helical gear HG1 in the axial direction L. Furthermore, the support member 8 is configured to rotatably support the rotor 12 via a first bearing B1. The first bearing B1 corresponds to a "rotor bearing." Furthermore, the support member 8 is fixed to the second case member 7. In this embodiment, the support member 8 is formed so as to separate the rotating electric machine chamber C1 and the gear chamber C2. In the illustrated example, the support member 8 is disposed between the rotating electric machine 1 and the transmission 2 in the axial direction L.

[0046] As described above, the vehicle drive device 100 a rotating electric machine 1 including a stator 11 and a rotor 12; a transmission 2 that changes the speed of the rotation transmitted from the rotor 12; a differential gear device 3 that distributes driving force from the rotating electric machine 1 transmitted via a transmission 2 to a pair of wheels W of the vehicle; A vehicle drive device 100 including a case 10 that houses a rotating electric machine 1, a transmission 2, and a differential gear device 3, A rotating electric machine 1, a transmission 2, and a differential gear device 3 are arranged coaxially, The transmission 2 includes a first helical gear HG1 and a second helical gear HG2 that meshes with the first helical gear HG1, The direction along the rotation axis of the rotor 12 is defined as the axial direction L, The case 10 includes a first case member 6 having a stator support portion 61 that supports the stator 11, a second case member 7 that is formed as a separate member from the first case member 6 and that forms a gear chamber C2 in which the transmission 2 and the differential gear device 3 are housed, and a support member 8 that supports the first helical gear HG1 in the axial direction L, The support member 8 rotatably supports the rotor 12 via a first bearing B1 serving as a rotor bearing, and is fixed to the second case member .

[0047] According to this configuration, the thrust force F acting on the first helical gear HG1 due to engagement with the second helical gear HG2 is transmitted to the second case member 7 via the support member 8 that supports the first helical gear HG1 in the axial direction L, and is supported by the support member 8 and the second case member 7. Furthermore, because the first case member 6 and the second case member 7 are configured as separate members, the thrust force F transmitted to the second case member 7 is unlikely to be transmitted to the first case member 6. Therefore, it is possible to keep to a minimum the distortion that occurs in the stator support portion 61 due to the thrust force F transmitted via the support member 8 that supports the first helical gear HG1 in the axial direction L. As a result, it is possible to avoid a deterioration in the performance of the rotating electric machine 1 due to deformation of the stator 11 supported by the stator support portion 61. Furthermore, according to this configuration, the support member 8 not only supports the first helical gear HG1 in the axial direction L, but also rotatably supports the rotor 12 via the first bearing B1 serving as a rotor bearing. In this way, the first helical gear HG1 and the first bearing B1 are supported by a single support member 8. This allows the vehicle drive device 100 to be made more compact than in a configuration in which the first bearing B1 is supported by a member separate from the support member 8.

[0048] As described above, in this embodiment, the first case member 6 and the second case member 7 are joined to each other in the axial direction L, The entire transmission 2 and the differential gear device 3 are housed in a second case member 7.

[0049] According to this configuration, even if the first case member 6 and the second case member 7 are joined to each other in the axial direction L, it is easy to ensure a wide rotating electric machine chamber C1 on the side of the first case member 6 in which the rotating electric machine 1 is housed.

[0050] As shown in FIG. 3, the second case member 7 has a fastened portion 73 to which the support member 8 is fastened by a fastening member 20. The fastened portion 73 is formed so that the fastening member 20 is fixed from the first axial side L1. In this embodiment, the fastened portion 73 is formed with a joint surface 7a facing the first axial side L1. In this example, the fastening member 20 is a bolt. The fastened portion 73 is formed with a screw hole into which the threaded portion of the fastening member 20 is screwed, the screw hole opening at the joint surface 7a.

[0051] In this embodiment, the support member 8 includes a bearing support portion 81, a fastening portion 82, a contact portion 83, and an engagement portion 84.

[0052] The bearing support portion 81 is configured to support the first bearing B1. In this embodiment, the bearing support portion 81 is formed such that the portion of the rotor shaft 12b that protrudes from the rotor core 12a to the second axial side L2 penetrates the bearing support portion 81 in the axial direction L, on a radially inner side R1 relative to the bearing support portion 81. The bearing support portion 81 rotatably supports the portion of the rotor shaft 12b that protrudes from the rotor core 12a to the second axial side L2 via the first bearing B1.

[0053] The fastening portion 82 is configured to be fastened to the fastened portion 73 of the second case member 7 by the fastening member 20. In this embodiment, the fastening portion 82 is fastened and fixed to the fastened portion 73 using the fastening member 20 in a state in which the fastening portion 82 abuts against the joint surface 7a from the first axial side L1. In this example, the multiple fastening portions 82 are arranged at intervals from each other in the circumferential direction C. In addition, in this example, a through hole through which a threaded portion of the fastening member 20 serving as a bolt is inserted is formed so as to penetrate the fastening portion 82 in the axial direction L.

[0054] The abutment portion 83 is configured so that the first helical gear HG1 abuts against it in the axial direction L. In this embodiment, the abutment portion 83 is arranged so that the first ring gear RG1, which serves as the first helical gear HG1, abuts against it from the second axial side L2. In this embodiment, the abutment portion 83 extends in the radial direction R and the circumferential direction C so as to connect the bearing support portion 81 and the fastening portion 82. In this example, the bearing support portion 81 is formed integrally with the end of the abutment portion 83 on the radially inner side R1. In addition, the fastening portion 82 is formed integrally with the end of the abutment portion 83 on the radially outer side R2.

[0055] The engaging portion 84 is configured to engage with the first helical gear HG1. In this embodiment, the engaging portion 84 is formed so that the first ring gear RG1 serving as the first helical gear HG1 can slide in the axial direction L but cannot rotate in the circumferential direction C. In the example shown, the engaging portion 84 protrudes from the abutting portion 83 to a second axial side L2 and further protrudes radially outward R2 so as to be located radially inward R1 with respect to the first ring gear RG1.

[0056] In this embodiment, the first ring gear RG1 abuts against the abutment portion 83 from the second axial side L2, thereby restricting relative movement of the first ring gear RG1 toward the first axial side L1 with respect to the engagement portion 84. Also, in this embodiment, a restricting member 30 such as a snap ring is provided on the inner periphery of the first ring gear RG1 so that the engagement portion 84 abuts against the second axial side L2. Therefore, the restricting member 30 restricts relative movement of the first ring gear RG1 toward the second axial side L2 with respect to the engagement portion 84. In this way, in this embodiment, the first ring gear RG1 serving as the first helical gear HG1 is engaged with the support member 8 so as to be non-rotatable relative to the support member 8. That is, in this embodiment, the support member 8 supports the first helical gear HG1 in the axial direction L and the circumferential direction C.

[0057] In this manner, in this embodiment, the second case member 7 has a joint surface 7a facing the first axial side L1, The support member 8 is fastened and fixed to the second case member 7 using fastening members 20 while abutting against the joint surface 7a from the first axial side L1, and supports the first helical gear HG1 in the axial direction L and the circumferential direction C.

[0058] According to this configuration, the thrust force F from the first helical gear HG1 can be appropriately supported by the support member 8. Furthermore, since the thrust force F acting on the support member 8 acts on the joint surface 7a of the second case member 7 in the axial direction L, it is easy to keep distortion of the second case member 7 small. Therefore, it is easy to keep distortion of the first case member 6 small as well.

[0059] In this embodiment, when the rotating electric machine 1 is driven so that the vehicle equipped with the vehicle drive device 100 moves forward, the thrust force F acting on the first helical gear HG1 due to meshing with the second helical gear HG2 acts toward the first axial side L1. In this example, the thrust force F from the first helical gear HG1 toward the first axial side L1 is received by the abutment portion 83 of the support member 8.

[0060] According to this configuration, the thrust force F from the first helical gear HG1 toward the first axial side L1 can be appropriately supported by the support member 8 while the vehicle is moving forward.

[0061] In this embodiment, the transmission 2 includes a planetary gear mechanism 21 having a carrier CR and a first ring gear RG1. The carrier CR is configured to rotatably support a first pinion gear PG1 that meshes with the first ring gear RG1, The second helical gear HG2 is the first pinion gear PG1, The first helical gear HG1 is a first ring gear RG1, and is engaged with the support member 8 so as to be non-rotatable relative to the support member 8.

[0062] In this configuration, the thrust force F acting on the first helical gear HG1 due to engagement with the second helical gear HG2 is easily transmitted to the support member 8, and is also easily transmitted to the second case member 7. Therefore, this configuration is suitable for application to a configuration in which the first case member 6 and the second case member 7 are formed as separate members, and the support member 8 is fixed to the second case member 7, as described above.

[0063] In this embodiment, in the above-described configuration in which the transmission 2 includes the planetary gear mechanism 21 having the carrier CR and the first ring gear RG1, The planetary gear mechanism 21 further includes a sun gear SG and a second ring gear RG2. The sun gear SG is connected to the rotor 12 so as to rotate integrally with the rotor 12. The second ring gear RG2 is disposed on a second axial side L2 relative to the first ring gear RG1, The carrier CR is configured to rotatably support the second pinion gear PG2 in addition to the first pinion gear PG1, The first pinion gear PG1 and the second pinion gear PG2 are connected to each other so as to rotate integrally with each other, The first pinion gear PG1 meshes with the sun gear SG and the first ring gear RG1, The second pinion gear PG2 has a smaller diameter than the first pinion gear PG1 and is in mesh with the second ring gear RG2.

[0064] According to this configuration, the transmission 2 can be configured as a reducer having a large reduction ratio.

[0065] Other Embodiments (1) In the above embodiment, the transmission 2 includes the planetary gear mechanism 21 having the sun gear SG, the carrier CR, the first ring gear RG1, and the second ring gear RG2, and the first ring gear RG1 and the first pinion gear PG1 are the first helical gear HG1 and the second helical gear HG2, respectively. However, without being limited to such a configuration, for example, the planetary gear mechanism 21 may be a single-pinion type planetary gear mechanism, and the ring gear of the planetary gear mechanism and the pinion gear that meshes with the ring gear may be the first helical gear HG1 and the second helical gear HG2, respectively.

[0066] (2) In the above embodiment, the transmission 2 functions as a reducer that reduces the rotation transmitted from the rotor 12 at a constant reduction ratio. However, the present invention is not limited to such a configuration, and the transmission 2 may be, for example, a transmission that can switch between multiple gear positions.

[0067] (3) In the above embodiment, an example has been described in which the first helical gear HG1 is engaged with the support member 8 so as not to rotate relative to it. However, the present invention is not limited to such a configuration, and the first helical gear HG1 may be supported so as to be rotatable relative to the support member 8. In this case, a thrust bearing may be disposed between the first helical gear HG1 and the support member 8 in the axial direction L.

[0068] (4) In the above embodiment, the first case member 6 and the second case member 7 are joined to each other in the axial direction L. However, the present invention is not limited to such a configuration, and for example, another case member may be interposed between the first case member 6 and the second case member 7 in the axial direction L.

[0069] (5) In the above embodiment, an example has been described in which the support member 8 is fastened to the second case member 7 using bolts as the fastening members 20. However, the present invention is not limited to such a configuration, and the support member 8 may be fastened to the second case member 7 by, for example, welding, riveting, or the like.

[0070] (6) In the above embodiment, the case 10 includes the cover member 9 in addition to the first case member 6, the second case member 7, and the support member 8. However, the present invention is not limited to such a configuration, and the case 10 may be configured without including the cover member 9. In this case, for example, the first case member 6 includes a wall portion corresponding to the cover member 9 (specifically, the third peripheral wall portion 91 and the second side wall portion 92). Furthermore, the case 10 may be configured with another member in addition to the first case member 6, the second case member 7, the support member 8, and the cover member 9.

[0071] (7) The configurations disclosed in the above-described embodiments can be applied in combination with configurations disclosed in other embodiments, as long as no contradictions arise. Regarding other configurations, the embodiments disclosed in this specification are merely examples in all respects. Therefore, various modifications can be made as appropriate within the scope of the present disclosure.

[0072] [Summary of the above embodiment] The vehicle drive device (100) described above will now be outlined.

[0073] The vehicle drive device (100) includes: a rotating electric machine (1) including a stator (11) and a rotor (12); a transmission (2) that changes the speed of the rotation transmitted from the rotor (12); a differential gear device (3) that distributes driving force transmitted from the rotating electric machine (1) via the transmission (2) to a pair of wheels (W) provided on the vehicle; a case (10) that houses the rotating electric machine (1), the transmission (2), and the differential gear device (3), The rotating electric machine (1), the transmission (2), and the differential gear device (3) are arranged coaxially, the transmission (2) includes a first helical gear (HG1) and a second helical gear (HG2) that meshes with the first helical gear (HG1); The direction along the rotation axis of the rotor (12) is defined as an axial direction (L), The case (10) includes a first case member (6) having a stator support portion (61) that supports the stator (11), a second case member (7) that is configured as a separate member from the first case member (6) and that forms a gear chamber (C2) in which the transmission (2) and the differential gear device (3) are housed, and a support member (8) that supports the first helical gear (HG1) in the axial direction (L), The support member (8) rotatably supports the rotor (12) via a rotor bearing (B1), and is fixed to the second case member (7).

[0074] According to this configuration, the thrust force (F) acting on the first helical gear (HG1) due to meshing with the second helical gear (HG2) is transmitted to the second case member (7) via the support member (8) that supports the first helical gear (HG1) in the axial direction (L), and is supported by the support member (8) and the second case member (7). Furthermore, because the first case member (6) and the second case member (7) are separate members, the thrust force (F) transmitted to the second case member (7) is less likely to be transmitted to the first case member (6). Therefore, distortion of the stator support portion (61) caused by the thrust force (F) transmitted via the support member (8) that supports the first helical gear (HG1) in the axial direction (L) can be minimized. As a result, it is possible to avoid a deterioration in the performance of the rotating electric machine (1) due to deformation of the stator (11) supported by the stator support portion (61). Furthermore, according to this configuration, the support member (8) not only supports the first helical gear (HG1) in the axial direction (L) but also rotatably supports the rotor (12) via the rotor bearing (B1). In this manner, the first helical gear (HG1) and the rotor bearing (B1) are supported by a single support member (8). This allows the vehicle drive device (100) to be made more compact than in a configuration in which the rotor bearing (B1) is supported by a member separate from the support member (8).

[0075] Here, in the axial direction (L), the side where the first case member (6) is disposed relative to the second case member (7) is defined as an axial first side (L1), When the rotating electric machine (1) is driven so as to move the vehicle forward, it is preferable that the thrust force (F) acting on the first helical gear (HG1) due to meshing with the second helical gear (HG2) acts toward the first axial side (L1).

[0076] According to this configuration, while the vehicle is moving forward, the thrust force (F) from the first helical gear (HG1) toward the first axial side (L1) can be appropriately supported by the support member (8).

[0077] The first case member (6) and the second case member (7) are joined together in the axial direction (L), It is preferable that the entire transmission (2) and the differential gear device (3) are housed in the second case member (7).

[0078] According to this configuration, even if the first case member (6) and the second case member (7) are joined to each other in the axial direction (L), it is easy to ensure a wide rotating electric machine chamber (C1) on the side of the first case member (6) in which the rotating electric machine (1) is housed.

[0079] Further, a direction around the rotation axis of the rotor (12) is defined as a circumferential direction (C), a side where the first case member (6) is disposed relative to the second case member (7) in the axial direction (L) is defined as a first axial side (L1), and a side opposite to the first axial side (L1) is defined as a second axial side (L2), The second case member (7) has a joint surface (7a) facing the first axial side (L1), It is preferable that the support member (8) is fastened and fixed to the second case member (7) using a fastening member (20) while abutting against the joint surface (7a) from the first axial side (L1), and supports the first helical gear (HG1) in the axial direction (L) and the circumferential direction (C).

[0080] According to this configuration, the thrust force F from the first helical gear HG1 can be appropriately supported by the support member 8. Furthermore, since the thrust force F acting on the support member 8 acts on the joint surface 7a of the second case member 7 in the axial direction L, distortion of the second case member 7 can be easily suppressed. Therefore, distortion of the first case member 6 can also be easily suppressed. [Industrial Applicability]

[0081] The technology disclosed herein can be used in a vehicle drive system that includes a rotating electric machine, a transmission that changes the speed of the rotation transmitted from the rotor of the rotating electric machine, a differential gear device that distributes the driving force from the rotating electric machine transmitted through the transmission to a pair of wheels, and a case that houses them. [Explanation of symbols]

[0082] 100: Vehicle drive device, 1: Rotating electric machine, 11: Stator, 12: Rotor, 2: Transmission, HG1: First helical gear, HG2: Second helical gear, 3: Differential gear device, 6: First case member, 61: Stator support portion, 7: Second case member, 8: Support member, 10: Case, C2: Gear chamber, W: Wheel, L: Axial direction

Claims

1. a rotating electric machine including a stator and a rotor; a transmission that changes the speed of the rotation transmitted from the rotor; a differential gear device that distributes driving force from the rotating electric machine transmitted via the transmission to a pair of wheels provided on the vehicle; a case that houses the rotating electric machine, the transmission, and the differential gear device, the rotating electric machine, the transmission, and the differential gear device are arranged coaxially, the transmission includes a first helical gear and a second helical gear that meshes with the first helical gear, A direction along the rotation axis of the rotor is defined as an axial direction, a direction perpendicular to the rotation axis is defined as a radial direction, and a direction around the rotation axis is defined as a circumferential direction, the case includes a first case member having a stator support portion that supports the stator, a second case member that is configured as a separate member from the first case member and that forms a gear chamber in which the transmission and the differential gear device are housed, and a support member that supports the first helical gear in the axial direction, the support member rotatably supports the rotor via a rotor bearing and is fixed to the second case member; the support member is formed to extend in the radial direction and the circumferential direction, and is positioned so as not to overlap with either the first helical gear or the second helical gear when viewed radially along the radial direction.

2. In the axial direction, a side on which the first case member is disposed relative to the second case member is defined as an axial first side, 2. The vehicle drive device according to claim 1, wherein, when the rotating electric machine is driven so as to move the vehicle forward, a thrust force acting on the first helical gear due to meshing with the second helical gear acts toward the first axial side.

3. the first case member and the second case member are joined to each other in the axial direction, 3. The vehicle drive system according to claim 1, wherein the transmission and the differential gear unit are entirely housed in the second case member.

4. In the axial direction, a side on which the first case member is disposed relative to the second case member is defined as an axial first side, and a side opposite to the axial first side is defined as an axial second side, the second case member has a joint surface facing the first axial side, 3. The vehicle drive device according to claim 1, wherein the support member is fastened to the second case member using a fastening member while abutting against the joint surface from the first axial side, and supports the first helical gear in the axial direction and the circumferential direction.

5. The support member comprises a bearing support portion that supports the rotor bearing, a fastening portion that is fastened and fixed to the second case member using a fastening member, and an abutment portion against which the first helical gear abuts in the axial direction; The vehicle drive device according to claim 1 or 2, wherein the abutment portion extends in the radial direction and the circumferential direction so as to connect the bearing support portion and the fastening portion.

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