Vehicle drive device

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 including a rotating electrical machine, a transmission that changes the rotation transmitted from the rotor of the rotating electrical machine, a differential gear device that distributes the driving force from the rotating electrical machine transmitted through the transmission to a pair of wheels, and a case that houses them.

Background Art

[0002] An example of such a vehicle drive device is disclosed in Patent Document 1 below. In the following description of the background art, the reference numerals in Patent Document 1 are 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 the stator (24) of the rotating electrical machine (2), and a second case member (12) that is formed of a member different from the first case member and forms a gear chamber in which the transmission (3) and the differential gear device (4) are housed. 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

Summary of the Invention

Problems 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 type planetary gear mechanism. The gears of the first planetary gear mechanism (31) and the second planetary gear mechanism (32) are helical gears.

[0006] Further, 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 the first case member (11) having a stator support portion.

[0007] In the above configuration, the thrust force acting on the first ring gear (R31) due to the meshing of the first planetary gear mechanism (31) with the first pinion gear and the thrust force acting on the second ring gear (R32) due to the meshing of the second planetary gear mechanism (32) with the second pinion gear 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), and consequently, the stator supported by the stator support portion may be deformed, leading to a decrease in the performance of the rotating electrical machine.

[0008] Therefore, it is desired to realize a vehicle drive device capable of significantly suppressing the distortion generated in the stator support portion due to the thrust force transmitted through the support member that axially supports the helical gear.

Means for Solving the Problems

[0009] In view of the above, the characteristic configuration of the vehicle drive device is a rotating electrical machine including a stator and a rotor, a transmission that shifts the rotation transmitted from the rotor, a differential gear device that distributes the driving force from the rotating electrical machine transmitted through the transmission to a pair of wheels provided in the vehicle, a vehicle drive device including a case that houses the rotating electrical machine, the transmission, and the differential gear device, wherein the rotating electrical 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, with the direction along the rotation axis of the rotor being defined as the axial direction, The case includes a first case member having a stator support portion for supporting the stator, a second case member that is a separate member from the first case member and forms a gear chamber in which the transmission and the differential gear device are accommodated, and a support member that supports the first spur 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 spur gear due to the meshing with the second spur gear is transmitted to the second case member via the support member that supports the first spur gear in the axial direction, and is supported by the support member and the second case member. Further, since the first case member and the second case member are configured as separate members, the thrust force transmitted to the second case member is difficult to be transmitted to the first case member. Therefore, the distortion generated in the stator support portion due to the thrust force transmitted via the support member that supports the first spur gear in the axial direction can be suppressed to a small level. As a result, it is possible to avoid the stator supported by the stator support portion from being deformed and the performance of the rotating electrical machine from deteriorating. Also, according to this characteristic configuration, in addition to supporting the first spur gear in the axial direction, the support member rotatably supports the rotor via a rotor bearing. In this way, the first spur gear and the rotor bearing are supported by one support member. Thereby, the vehicle drive device can be downsized compared to a configuration in which the rotor bearing is supported by a member separate from the support member.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Mode for Carrying Out the Invention

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

[0013] In the following description, the direction along the rotation axis center of the rotor 12 (see the one-dot chain line in FIG. 1) is defined as the "axial direction L". One side of the axial direction L is defined as the "first axial side L1", and the other side of the axial direction L is defined as the "second axial side L2". Further, the direction orthogonal to the rotation axis center of the rotor 12 is defined as the "radial direction R". And in the radial direction R, the side closer to the rotation axis center of the rotor 12 is defined as the "radial inner side R1", and the opposite side is defined as the "radial outer side R2". Also, the direction of orbiting around the rotation axis center of the rotor 12 is defined as the "circumferential direction C".

[0014] The rotating electric machine 1, the transmission 2, and the differential gear device 3 are arranged coaxially. In the present embodiment, the rotating electric machine 1, the transmission 2, and the differential gear device 3 are arranged in the described order 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 generates power upon receiving power supply and a function as a generator (electric generator) that generates power upon receiving power supply. Specifically, the rotating electric machine 1 is electrically connected to a power storage device (not shown) such as a battery or a capacitor. And the rotating electric machine 1 generates a driving force by traveling with the power stored in the power storage device. Also, the rotating electric machine 1 generates electricity by the driving force transmitted from the side of the pair of wheels W and charges the power storage device.

[0016] The stator 11 of the rotating electrical machine 1 includes a cylindrical stator core 11a. The stator core 11a is fixed to the case 10. The rotor 12 of the rotating electrical machine 1 includes a cylindrical rotor core 12a. The rotor core 12a is rotatably supported with respect to the stator core 11a. In the present embodiment, the rotor 12 further includes a rotor shaft 12b that is connected 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 the present embodiment, the rotating electrical machine 1 is an inner rotor type rotating electrical machine. Therefore, the rotor core 12a is disposed on the radially inner side R1 with respect to the stator core 11a. Also, the rotor shaft 12b is disposed on the radially inner side R1 with respect to the rotor core 12a.

[0018] Also, in the present embodiment, the rotating electrical machine 1 is a rotating field type rotating electrical machine. Therefore, the stator 11 further includes a stator coil 11b. In the present embodiment, the stator coil 11b is wound around the stator core 11a such that a first coil end portion 11c protruding to the first axial side L1 with respect to the stator core 11a and a second coil end portion 11d protruding to the second axial side L2 with respect to the stator core 11a are formed. Also, although not shown, permanent magnets are provided on the rotor core 12a.

[0019] As shown in FIG. 3, in the present embodiment, the transmission 2 includes a planetary gear mechanism 21. In the present 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 so as to rotate integrally with the rotor 12. In the illustrated example, the sun gear SG is connected so as to rotate integrally with the rotor shaft 12b by welding or the like.

[0021] In this embodiment, the carrier CR is configured to rotatably support the first pinion gear PG1 and the second pinion gear PG2. The first pinion gear PG1 and the second pinion gear PG2 are connected 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 side L2 in the axial direction with respect to the first ring gear RG1. And the second ring gear RG2 is connected to rotate integrally with the input element of the differential gear device 3. Details of the connection modes of these ring gears RG1 and RG2 will be described later.

[0023] Each of the sun gear SG, the first pinion gear PG1, the second pinion gear PG2, the first ring gear RG1, and the second ring gear RG2 is a helical gear. Here, a helical gear is a gear in which the tooth flanks are 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 decelerated in the planetary gear mechanism 21 and transmitted to the differential gear device 3. That is, in this embodiment, the transmission 2 functions as a speed reducer that decelerates 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 so as to rotate integrally with the second ring gear RG2 of the planetary gear mechanism 21. In the illustrated example, the differential case 31 is connected by welding so as to rotate integrally with the second ring gear RG2.

[0027] The shaft member 32 is arranged to extend along the radial direction R. And the shaft member 32 is supported by the differential case 31 so as to rotate integrally with the differential case 31. In the present embodiment, a plurality of shaft members 32 are arranged in a dispersed manner in the circumferential direction C along the radial direction R (for example, in a configuration in which four shaft members 32 are arranged in a cross shape in an axial direction view 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 (self-rotatable) about the shaft member 32 and rotatable (revolvable) about the rotation axis of the differential case 31. In the present embodiment, the pinion gear 33 is attached to each of the plurality of shaft members 32.

[0029] The first side gear 34 and the second side gear 35 are engaged 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 the first axial side L1 with respect to the shaft member 32. And the second side gear 35 is arranged on the second axial side L2 with respect to the shaft member 32.

[0030] In the present embodiment, the first side gear 34 is connected so as to rotate integrally with the first drive shaft DS1 that is drivingly connected to the wheel W on the first axial side L1 via the output shaft member 4 extending along the axial direction L. In the illustrated example, the output shaft member 4 is inserted into the radially inner side R1 with respect to the first side gear 34 from the first axial side L1, and they are connected to each other by spline engagement.

[0031] The output shaft member 4 is arranged so as to penetrate radially inward R1 in the axial direction L with respect to the transmission 2 and the rotary electric machine 1. In the present embodiment, the output shaft member 4 is arranged so as to penetrate radially inward R1 in the axial direction L with respect to the sun gear SG of the planetary gear mechanism 21 and the rotor shaft 12b of the rotary electric machine 1.

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

[0033] As shown in FIG. 1, the case 10 includes a first case member 6, a second case member 7, and a support member 8. In the present 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 in which the rotary electric machine 1 is housed. The first case member 6 includes a stator support portion 61 that supports the stator 11 of the rotary electric machine 1.

[0035] In the present embodiment, the first case member 6 further includes a first peripheral wall portion 62. The first peripheral wall portion 62 is formed so as to surround the rotary electric machine chamber C1 in the circumferential direction C. In the present embodiment, the first peripheral wall portion 62 is formed in a cylindrical shape that covers the radially outer side R2 of the stator core 11a. Further, in the present embodiment, the stator support portion 61 is integrally formed with the first peripheral wall portion 62. And the stator core 11a is fixed to the stator support portion 61. Note that, in the present embodiment, the first peripheral wall portion 62 does not cover the radially outer side R2 of the first coil end portion 11c and the second coil end portion 11d of the rotary electric machine 1. That is, in the present embodiment, the first case member 6 is configured to form a part of the rotary electric machine chamber C1.

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

[0037] The second peripheral wall portion 71 is formed so as to surround the gear chamber C2 in the circumferential direction C. In the present embodiment, the second peripheral wall portion 71 is formed in a cylindrical shape that covers the radially outer side R2 of the transmission 2 and the differential gear device 3. And the second peripheral wall portion 71 is formed so as to overlap the entire transmission 2 and the differential gear device 3 in a radial view along the radial direction R. That is, in the present embodiment, the entire transmission 2 and the differential gear device 3 are housed in the second case member 7. Regarding the arrangement of two elements, "overlapping in a specific direction view" means that when a virtual straight line parallel to the line-of-sight direction is moved in each direction orthogonal to the virtual straight line, there is at least a part of a region where the virtual straight line intersects both of the two elements.

[0038] Also, in the present 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 the present embodiment, the second case member 7 is configured to form a part of the rotating electric machine chamber C1 in addition to the gear chamber C2.

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

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

[0041] The third circumferential wall portion 91 is formed so as to surround the rotating electrical machine chamber C1. In the present embodiment, the third circumferential 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 electrical machine 1. That is, in the present embodiment, the cover member 9 is configured to form a part of the rotating electrical machine chamber C1.

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

[0043] In the present embodiment, the first case member 6 is joined to the second case member 7 from the first side L1 in the axial direction. That is, in the axial direction L, the side where the first case member 6 is arranged with respect to the second case member 7 is the first side L1 in the axial direction. Thus, in the present embodiment, the first case member 6 and the second case member 7 are joined to each other in the axial direction L. In the illustrated example, the first case member 6 and the second case member 7 are joined such that the first circumferential wall portion 62 and the second circumferential wall portion 71 contact each other in the axial direction L.

[0044] Also, in the present embodiment, the cover member 9 is joined to the first case member 6 from the first side L1 in the axial direction. In the illustrated example, the cover member 9 and the first case member 6 are joined such that the third circumferential wall portion 91 and the first circumferential wall portion 62 contact each other in the axial direction L.

[0045] As shown in FIG. 3, the support member 8 is configured to support the first spur gear HG1 in the axial direction L. Further, the support member 8 is configured to rotatably support the rotor 12 via the first bearing B1. Note that the first bearing B1 corresponds to a "rotor bearing". Also, the support member 8 is fixed to the second case member 7. In the present embodiment, the support member 8 is formed so as to partition 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 includes a rotating electric machine 1 having a stator 11 and a rotor 12, a transmission 2 that changes the rotation transmitted from the rotor 12, a differential gear device 3 that distributes the driving force from the rotating electric machine 1 transmitted via the transmission 2 to a pair of wheels W provided in the vehicle, and a case 10 that houses the rotating electric machine 1, the transmission 2, and the differential gear device 3. The vehicle drive device 100 has the rotating electric machine 1, the transmission 2, and the differential gear device 3 arranged coaxially, the transmission 2 includes a first spur gear HG1 and a second spur gear HG2 that meshes with the first spur gear HG1, with the direction along the rotation axis of the rotor 12 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 a separate member from the first case member 6 and 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 spur gear HG1 in the axial direction L, the support member 8 rotatably supports the rotor 12 via the first bearing B1 as a rotor bearing and is fixed to the second case member 7.

[0047] According to this configuration, the thrust force F that the second spur gear HG2 exerts on the first spur gear HG1 through meshing is transmitted to the second case member 7 via the support member 8 that supports the first spur gear HG1 in the axial direction L, and is supported by the support member 8 and the second case member 7. Further, since 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 difficult to be transmitted to the first case member 6. Therefore, the distortion generated in the stator support portion 61 due to the thrust force F transmitted through the support member 8 that supports the first spur gear HG1 in the axial direction L can be suppressed to a small level. As a result, it is possible to avoid the stator 11 supported by the stator support portion 61 from being deformed and the performance of the rotating electrical machine 1 from deteriorating. Further, according to this configuration, in addition to supporting the first spur gear HG1 in the axial direction L, the support member 8 also rotatably supports the rotor 12 via the first bearing B1 as a rotor bearing. In this way, the first spur gear HG1 and the first bearing B1 are supported by one support member 8. Thereby, the vehicle drive device 100 can be downsized as compared with a configuration in which the first bearing B1 is supported by a member separate from the support member 8.

[0048] Also, as described above, in the present 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 differential gear device 3 are housed in the second case member 7.

[0049] According to this configuration, even in a configuration where 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 widely secure the rotating electrical machine chamber C1 in which the rotating electrical machine 1 is housed on the side of the first case member 6.

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

[0051] In the present 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 the present embodiment, the bearing support portion 81 is formed such that a radially inner side R1 with respect to the bearing support portion 81 is penetrated in the axial direction L by a portion protruding from the rotor core 12a in the rotor shaft 12b to the second axial side L2. And, the bearing support portion 81 rotatably supports a portion protruding from the rotor core 12a in the rotor shaft 12b 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 the present embodiment, the fastening portion 82 is fastened and fixed to the fastened portion 73 using the fastening member 20 in a state of contacting the joint surface 7a from the first axial side L1. In this example, a plurality of fastening portions 82 are arranged at intervals in the circumferential direction C. Also, in this example, a through hole through which the threaded portion of the fastening member 20 as a bolt is inserted is formed so as to penetrate the fastening portion 82 in the axial direction L.

[0054] The abutting portion 83 is configured such that the first spur gear HG1 abuts in the axial direction L. In the present embodiment, the abutting portion 83 is arranged such that the first ring gear RG1 as the first spur gear HG1 abuts from the second side L2 in the axial direction. Further, in the present embodiment, the abutting 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 integrally formed at the end portion on the inner side R1 in the radial direction of the abutting portion 83. Also, the fastening portion 82 is integrally formed at the end portion on the outer side R2 in the radial direction of the abutting portion 83.

[0055] The engaging portion 84 is configured such that the first spur gear HG1 engages therewith. In the present embodiment, the engaging portion 84 is formed such that the first ring gear RG1 as the first spur gear HG1 engages slidably in the axial direction L and non-rotatably in the circumferential direction C. In the illustrated example, the engaging portion 84 protrudes from the abutting portion 83 to the second side L2 in the axial direction and further protrudes to the outer side R2 in the radial direction so as to be positioned on the inner side R1 in the radial direction with respect to the first ring gear RG1.

[0056] In the present embodiment, when the first ring gear RG1 abuts against the abutting portion 83 from the second side L2 in the axial direction, the relative movement of the first ring gear RG1 to the first side L1 in the axial direction with respect to the engaging portion 84 is restricted. Further, in the present embodiment, a restricting member 30 such as a snap ring is provided on the inner peripheral portion of the first ring gear RG1 so that the engaging portion 84 abuts from the second side L2 in the axial direction. Therefore, the relative movement of the first ring gear RG1 to the second side L2 in the axial direction with respect to the engaging portion 84 is restricted by the restricting member 30. Thus, in the present embodiment, the first ring gear RG1 as the first spur gear HG1 is engaged with the support member 8 in a non-rotatable manner. That is, in the present embodiment, the support member 8 supports the first spur gear HG1 in the axial direction L and the circumferential direction C.

[0057] Thus, in the present embodiment, the second case member 7 includes a joint surface 7a facing the first side L1 in the axial direction. The support member 8 is fastened and fixed to the second case member 7 using the fastening member 20 while being in contact with 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. Further, since the thrust force F acting on the support member 8 acts in the axial direction L with respect to the joint surface 7a of the second case member 7, it is easy to suppress the distortion of the second case member 7 to a small level. Therefore, it is also easy to suppress the distortion of the first case member 6 to a small level.

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

[0060] According to this configuration, during the forward movement of the vehicle, 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.

[0061] Also, in the present 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 the first ring gear RG1 and is engaged with the support member 8 so as not to be relatively rotatable.

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

[0063] Also, in the present embodiment, in the above 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 so as to rotate integrally with the rotor 12, the second ring gear RG2 is disposed on the second side L2 in the axial direction with respect 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 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 meshes with the second ring gear RG2.

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

[0065] 〔Other Embodiments〕 (1) In the above-described embodiment, the transmission 2 is described by taking as an example a configuration including a planetary gear mechanism 21 having a sun gear SG, a carrier CR, a first ring gear RG1, and a second ring gear RG2, and the first ring gear RG1 and the first pinion gear PG1 are respectively the first spur gear HG1 and the second spur gear HG2. However, the configuration is not 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 meshing with the ring gear may be the first spur gear HG1 and the second spur gear HG2, respectively.

[0066] (2) In the above-described embodiment, the configuration in which the transmission 2 functions as a speed reducer that reduces the rotation transmitted from the rotor 12 at a constant reduction ratio is described as an example. However, the configuration is not limited to such a configuration. For example, the transmission 2 may be a transmission that can be switched to a plurality of speed stages.

[0067] (3) In the above-described embodiment, the configuration in which the first spur gear HG1 is engaged with the support member 8 so as not to be relatively rotatable is described as an example. However, the configuration is not limited to such a configuration. The first spur gear HG1 may be supported by the support member 8 so as to be relatively rotatable. In this case, a thrust bearing may be disposed between the first spur gear HG1 and the support member 8 in the axial direction L.

[0068] (4) In the above-described embodiment, the configuration in which the first case member 6 and the second case member 7 are joined to each other in the axial direction L is described as an example. However, the configuration is not limited to such a configuration. 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-described embodiment, the configuration in which the support member 8 is fastened and fixed to the second case member 7 using a bolt as the fastening member 20 is described as an example. However, the configuration is not limited to such a configuration. For example, the support member 8 may be fixed to the second case member 7 by welding, riveting, or the like.

[0070] (6) In the above-described embodiment, the case 10 was described by taking as an example the configuration including the cover member 9 in addition to the first case member 6, the second case member 7, and the support member 8. However, the configuration is not limited to such a configuration, and for example, the case 10 may have a configuration without 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). Further, the case 10 may have a configuration including still 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) Note that the configurations disclosed in the above-described embodiments can be applied in combination with the configurations disclosed in other embodiments as long as no contradiction occurs. Regarding other configurations as well, all the embodiments disclosed in this specification are merely examples in all respects. Therefore, various modifications can be made as appropriate within the scope not departing from the gist of the present disclosure.

[0072] [Outline of the above embodiment] Hereinafter, the outline of the vehicle drive device (100) described above will be described.

[0073] The vehicle drive device (100) includes an electric rotating machine (1) including a stator (11) and a rotor (12), a transmission (2) that shifts the rotation transmitted from the rotor (12), a differential gear device (3) that distributes the driving force from the electric rotating machine (1) transmitted through the transmission (2) to a pair of wheels (W) provided in the vehicle, and a case (10) that houses the electric rotating machine (1), the transmission (2), and the differential gear device (3). The vehicle drive device (100) is such that the electric rotating machine (1), the transmission (2), and the differential gear device (3) are arranged coaxially, the transmission (2) includes a first spur gear (HG1) and a second spur gear (HG2) that meshes with the first spur gear (HG1), Taking the direction along the rotation axis of the rotor (12) as the axial direction (L), The case (10) includes a first case member (6) having a stator support portion (61) for supporting the stator (11), a second case member (7) which is a separate member from the first case member (6) and forms a gear chamber (C2) in which the transmission (2) and the differential gear device (3) are housed, and a support member (8) for supporting the first spur 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 spur gear (HG1) due to the engagement with the second spur gear (HG2) is transmitted to the second case member (7) via the support member (8) that supports the first spur gear (HG1) in the axial direction (L), and is supported by the support member (8) and the second case member (7). Further, since 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 difficult to be transmitted to the first case member (6). Therefore, the distortion generated in the stator support portion (61) due to the thrust force (F) transmitted via the support member (8) that supports the first spur gear (HG1) in the axial direction (L) can be suppressed to a small level. As a result, it is possible to avoid the stator (11) supported by the stator support portion (61) from being deformed and the performance of the rotating electrical machine (1) from deteriorating. Also, according to this configuration, in addition to supporting the first spur gear (HG1) in the axial direction (L), the support member (8) rotatably supports the rotor (12) via the rotor bearing (B1). In this way, the first spur gear (HG1) and the rotor bearing (B1) are supported by one support member (8). Thereby, the vehicle drive device (100) can be miniaturized as compared with 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), with the side where the first case member (6) is arranged with respect to the second case member (7) being defined as the first axial side (L1), When the rotary electric machine (1) is driven so that the vehicle moves forward, it is preferable that the thrust force (F) acting on the first spur gear (HG1) due to meshing with the second spur gear (HG2) acts toward the first axial side (L1).

[0076] According to this configuration, during forward movement of the vehicle, the thrust force (F) directed from the first spur gear (HG1) toward the first axial side (L1) can be appropriately supported by the support member (8).

[0077] Also, the first case member (6) and the second case member (7) are joined to each other in the axial direction (L), and 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 in a configuration where 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 widely secure the rotary electric machine chamber (C1) in which the rotary electric machine (1) is housed on the side of the first case member (6).

[0079] Also, with the direction of orbiting around the rotational axis center of the rotor (12) being defined as the circumferential direction (C), in the axial direction (L), with the side where the first case member (6) is arranged with respect to the second case member (7) being defined as the first axial side (L1), and the side opposite to the first axial side (L1) being defined as the second axial side (L2), the second case member (7) is provided with 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 a fastening member (20) in a state of abutting against the joint surface (7a) from the first axial side (L1), and preferably supports the first spur gear (HG1) in the axial direction (L) and the circumferential direction (C).

[0080] According to this configuration, the first hypoid gear (HG1) can be appropriately supported by the support member (8) against the thrust force (F). Further, since the thrust force (F) acting on the support member (8) acts in the axial direction (L) with respect to the joint surface (7a) of the second case member (7), it is easy to greatly suppress the distortion of the second case member (7). Therefore, it is also easy to greatly suppress the distortion of the first case member (6).

Industrial Applicability

[0081] The technology according to the present disclosure can be used in a vehicle drive device including a rotating electric machine, a transmission that changes 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 Signs

[0082] 100: Vehicle drive device, 1: Rotating electric machine, 11: Stator, 12: Rotor, 2: Transmission, HG1: First hypoid gear, HG2: Second hypoid 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 a 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 coaxially arranged, 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 an 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.

2. In the axial direction, a side on which the first case member is disposed with respect to the second case member is defined as a first axial 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 device according to claim 1, wherein the transmission and the differential gear device are entirely housed in the second case member.

4. A direction going around the rotation axis of the rotor is defined as a circumferential direction, a side where the first case member is disposed with respect to the second case member in the axial direction 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 includes a joint surface facing the first axial direction 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 and circumferential directions.

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