Vehicle drive systems

Abstract

This invention provides a vehicle drive system that can easily reduce the noise emitted to the outside of the case due to vibrations in the gear mechanism. [Solution] The case 90 of the vehicle drive unit comprises a first case portion 91 that forms at least a part of a first housing chamber E1 in which a rotating electric machine MG is housed, a second case portion 92 that forms at least a part of a second housing chamber E2 in which a gear mechanism 15 is housed, and an intermediate support portion 93 disposed between the first housing chamber E1 and the second housing chamber E2. The intermediate support portion 93 comprises a bearing holding portion 94 that holds a third bearing B3 that rotatably supports the rotor shaft 13, a gear support portion 95 that supports the gear mechanism 15, and a fixing portion 96 that is fixed to at least one of the first case portion 91 and the second case portion 92. The fixing portion 96 is located radially outward R2 from the bearing holding portion 94 and the gear support portion 95, and axially first side L1 from the third bearing B3.

Description

Technical Field

[0006] , , , ,

[0001] The present invention relates to a vehicle drive device including a rotating electric machine.

Background Art

[0002] A vehicle drive device including a rotating electric machine is known. Japanese Unexamined Patent Application Publication No. 2024-090827 (Patent Document 1) discloses a vehicle drive device including a case (9) that houses a rotating electric machine (1) and a gear mechanism including a first planetary gear (PG1) and a first ring gear (RG1) that mesh with each other.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a vehicle drive device such as that of Patent Document 1, vibration may occur due to the meshing of the gears included in the gear mechanism. When such vibration is transmitted to the outer wall of the case, there is a possibility that a sound of a size that can be heard by, for example, a person may be emitted from the outer wall to the outside of the case.

[0005] Therefore, it is desired to realize a vehicle drive device that can easily reduce the sound emitted to the outside of the case due to the vibration of the gear mechanism.

Means for Solving the Problems

[0006] The vehicle drive system according to this disclosure comprises a rotating electric machine equipped with a rotor, an output member driven to a wheel, a gear mechanism for transmitting driving force between the rotating electric machine and the output member, and a case housing the rotating electric machine and the gear mechanism, wherein the case comprises a first case portion forming at least a part of a first housing chamber housing the rotating electric machine, a second case portion forming at least a part of a second housing chamber housing the gear mechanism, and an intermediate support portion disposed between the first housing chamber and the second housing chamber, wherein the direction along the rotation axis of the rotor is defined as the axial direction, one side in the axial direction is defined as the axial first side, and the other side in the axial direction is defined as the axial second side. Furthermore, with the direction perpendicular to the rotation axis being the radial direction, the gear mechanism is positioned on the rotation axis on the second axial side relative to the rotor, and a rotor bearing is positioned between the rotor and the gear mechanism in the axial direction, rotatably supporting a rotor shaft that rotates integrally with the rotor. The intermediate support portion comprises a bearing holding portion that holds the rotor bearing, a gear support portion that supports the gear mechanism, and a fixing portion fixed to at least one of the first case portion and the second case portion, wherein the fixing portion is positioned radially outward from the bearing holding portion and the gear support portion and on the first axial side relative to the rotor bearing.

[0007] In this configuration, the fixing portion fixed to the case in the intermediate support section is located radially outward from the bearing holder and gear support section and on the first axial side of the rotor bearing, which tends to lengthen the vibration transmission path from the bearing holder and gear support section to the fixing portion. Therefore, vibrations from the gear mechanism and the like can be attenuated and transmitted to the outer wall of the case. This makes it easier to reduce the noise emitted from the case to the outside due to vibrations of the gear mechanism. [Brief explanation of the drawing]

[0008] [Figure 1] Outline diagram of a vehicle drive system according to an embodiment [Figure 2] A cross-sectional view along the axial direction of a vehicle drive system according to an embodiment. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments of the vehicle drive system 10 will be described with reference to the drawings.

[0010] Figure 1 shows an example of a vehicle 8 equipped with a vehicle drive unit 10. The vehicle drive unit 10 includes a rotating electric motor MG. The rotating electric motor MG is the driving force source for the vehicle 8. Examples of vehicle 8 include battery electric vehicles (BEVs), fuel cell electric vehicles (FCEVs), hybrid electric vehicles (HEVs) equipped with an internal combustion engine and a rotating electric motor, plug-in hybrid electric vehicles (PHEVs), etc. The vehicle 8 may be a three-wheeled vehicle or a four-wheeled vehicle. In this embodiment, the vehicle 8 is a four-wheeled battery vehicle. In this embodiment, the vehicle 8 has a pair of wheels (first wheel W1, second wheel W2). The vehicle drive unit 10 includes a case 90 that houses the rotating electric motor MG.

[0011] The rotating electric machine MG functions as a driving force source for the wheels (first wheel W1, second wheel W2). The rotating electric machine MG has the function of a motor that generates power when power is supplied, and the function of a generator that generates power when power is supplied. Specifically, the rotating electric machine MG is electrically connected to an energy storage device such as a battery or capacitor (not shown). The rotating electric machine MG then generates driving force by moving using the power stored in the energy storage device. In addition, the rotating electric machine MG generates electricity using the driving force transmitted from the wheels (first wheel W1, second wheel W2) to charge the energy storage device. In this embodiment, the rotating electric machine MG is an inner rotor type rotating electric machine.

[0012] Figure 2 is a cross-sectional view showing an example of a vehicle drive unit 10. The rotating electric machine MG includes a rotor 12. The rotating electric machine MG includes a stator 11. Here, the direction along the rotation axis A1, which is the rotation axis of the rotor 12, 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. The direction perpendicular to the rotation axis A1 is defined as the "radial direction R". In the radial direction R, the side facing the rotation axis A1 is defined as the inner side R1, and the opposite side is defined as the outer side R2. The direction around the rotation axis A1 is defined as the "circumferential direction C".

[0013] The vehicle drive unit 10 includes a rotor shaft 13 that rotates integrally with the rotor 12. The rotor shaft 13 is formed in a cylindrical shape. The vehicle drive unit 10 includes a second bearing B2 and a third bearing B3 that rotatably support the rotor shaft 13.

[0014] The stator 11 of the rotating electric machine MG is equipped with a cylindrical stator core 11a. The stator core 11a is fixed to the case 90. The stator 11 is equipped with a stator coil 11b. The stator coil 11b is wound around the stator core 11a such that coil end portions are formed that protrude from the stator core 11a on both sides in the axial direction L. In this embodiment, the rotating electric machine MG is a rotating field type rotating electric machine.

[0015] The rotor 12 of the rotating electric machine MG is equipped with a cylindrical rotor core 12a. The rotor core 12a is rotatably supported relative to the stator core 11a. In this embodiment, the rotor core 12a is connected to the rotor shaft 13 so as to rotate integrally with it. In this embodiment, the rotor shaft 13 is positioned so as to penetrate the inner radial R1 of the rotor core 12a in the axial direction L. Permanent magnets are provided on the rotor core 12a.

[0016] The vehicle drive unit 10 is equipped with an output member. The output member is driven and connected to the wheels (first wheel W1, second wheel W2). Examples of the "output member" include the first bevel gear 62, the second bevel gear 63, their spline engagement portions 63d, the first drive shaft DS1, the second drive shaft DS2, the connecting shaft 17, etc., which will be described later. In this embodiment, the spline engagement portion 63d is the output member.

[0017] Here, "drive connection" refers to a state in which two rotating elements are connected in a manner that allows for the transmission of driving force, and includes a state in which the two rotating elements are connected so as to rotate as a whole, or a state in which the two rotating elements are connected in a manner that allows for the transmission of driving force via one or more transmission members. Such transmission members include various members that transmit rotation at the same speed or at a variable speed, such as shafts, gear mechanisms, belts, chains, etc. Furthermore, the transmission members may also include engagement devices that selectively transmit rotation and driving force, such as friction engagement devices and meshing engagement devices. However, when referring to a "drive connection" with respect to the rotating elements of a planetary gear mechanism, it refers to a state in which they are drive-connected without the need for other rotating elements of the planetary gear mechanism.

[0018] Furthermore, "rotating as a whole" means rotating as a single unit, regardless of whether the components are separable or not. In other words, multiple components that rotate as a whole may be formed integrally from the same component, or they may be composed of separate components and integrated by welding, spline connections, or the like.

[0019] The vehicle drive unit 10 includes a gear mechanism 15 that transmits driving force between the rotating electric machine MG and the output member. On the rotation axis A1, the gear mechanism 15 is positioned on the second axial side L2 relative to the rotor 12. Between the rotor 12 and the gear mechanism 15, a third bearing B3 is positioned to rotatably support the rotor shaft 13, which rotates integrally with the rotor 12. The third bearing B3 corresponds to the "rotor bearing".

[0020] Examples of the gear mechanism 15 include a speed reducer 30, a differential gear device 40, a two-stage or multi-stage transmission with three or more stages, a continuously variable transmission having gears, and the like. In the present embodiment, the gear mechanism 15 is both the speed reducer 30 and the differential gear device 40. The speed reducer 30 reduces the rotation of the rotor 12 and transmits it to the output member side. The differential gear device 40 distributes the driving force transmitted from the side of the rotating electric machine MG to a pair of output members. Note that the gear mechanism 15 may be one of the speed reducer 30 and the differential gear device 40.

[0021] The vehicle drive device 10 includes a connecting shaft 17 connected so as to rotate integrally with one of a pair of output members. In the present embodiment, the rotor 12, the pair of output members, and the connecting shaft 17 are arranged on the rotation axis center A1. In the present embodiment, the speed reducer 30 is arranged on the rotation axis center A1.

[0022] The rotor 12 is arranged on the first axial side L1 with respect to the differential gear device 40. In the present embodiment, the rotor 12, the speed reducer 30, and the differential gear device 40 are arranged in this order from the first axial side L1 toward the second axial side L2. In the present embodiment, the rotation axes of the rotating electric machine MG, the speed reducer 30, and the output member are coaxial. Note that when the rotation axes of the rotating electric machine MG, the speed reducer 30, and the output member are different, one of the speed reducer 30 and the differential gear device 40 may overlap with the rotor 12 in a radial view along the radial direction R.

[0023] The speed reducer 30 is configured using a planetary gear mechanism. The planetary gear mechanism included in the speed reducer 30 includes a sun gear SG. The sun gear SG is connected so as to rotate integrally with the rotor 12. In the present embodiment, the sun gear SG is connected so as to rotate integrally with the rotor shaft 13 by welding.

[0024] The planetary gear mechanism included in the speed reducer 30 includes a carrier CR. The carrier CR is configured to rotatably support the first planetary gear PG1 and the second planetary gear PG2. The first planetary gear PG1 and the second planetary gear PG2 are connected so as to rotate integrally with each other.

[0025] The planetary gear mechanism of the reduction gear 30 includes a first ring gear RG1. The first ring gear RG1 is fixed to the case 90. The first planetary gear PG1 meshes with the sun gear SG and the first ring gear RG1. The planetary gear mechanism also includes a second ring gear RG2. The second planetary gear PG2 meshes with the second ring gear RG2. The second planetary gear PG2 is formed to have a smaller diameter than the first planetary gear PG1. The second ring gear RG2 transmits rotation to the input element of the differential gear device 40, which will be described later. In this embodiment, the reduction gear 30 reduces the rotation of the rotor 12 and transmits it to the differential gear device 40.

[0026] The differential gear unit 40 comprises a differential case 50 and a differential gear mechanism 60 housed within the differential case 50. In this embodiment, the differential gear unit 40 is a bevel gear type differential gear unit. In this embodiment, both the reducer 30 and the differential gear unit 40 are housed in a case 90.

[0027] The differential case 50 is configured to rotate about the rotation axis of the output member. The differential case 50 rotates integrally with the second ring gear RG2. The differential case 50 is an input element of the differential gear device 40. The differential case 50 has a structure that is divided into two parts in the axial direction L. In this embodiment, the rotation axis of the output member is coaxial with the rotation axis A1.

[0028] The differential case 50 comprises a first member 51 and a second member 52. The first member 51 and the second member 52 are configured to be joined to each other in the axial direction L. In this embodiment, the first member 51 is formed to cover the differential gear mechanism 60 from the first axial side L1. The second member 52 is formed to cover the differential gear mechanism 60 from the second axial side L2.

[0029] The differential case 50 includes a ring gear fixing portion 53. The ring gear fixing portion 53 is fixed to the second ring gear RG2. In this embodiment, the ring gear fixing portion 53 is fixed to the second ring gear RG2 by welding. The ring gear fixing portion 53 is formed to protrude radially outward R2 from the first member 51.

[0030] The differential gear mechanism 60 comprises a support shaft member 61, a plurality of first bevel gears 62, and a pair of second bevel gears 63. The support shaft member 61 is fixed to the differential case 50. The support shaft member 61 rotates integrally with the differential case 50. The support shaft member 61 is fixed between the first member 51 and the second member 52 of the differential case 50, sandwiched from both sides in the axial direction L.

[0031] Each of the multiple first bevel gears 62 is configured to rotate freely around its axis and to revolve freely around the rotation axis of the output member. The differential case 50 houses the multiple first bevel gears 62 and a pair of second bevel gears 63 inside.

[0032] One of the pair of second bevel gears 63 is driven and connected to the first wheel W1, which is the wheel on the axial first side L1, via a connecting shaft 17. The other of the pair of second bevel gears 63 is connected to the second drive shaft DS2, which is driven and connected to the second wheel W2, which is the wheel on the axial second side L2, so as to rotate integrally with it. Each of the pair of second bevel gears 63 comprises a gear portion that meshes with the first bevel gear 62 and a spline engagement portion 63d that is connected to the connecting shaft 17 or the second drive shaft DS2.

[0033] The first bevel gear 62 is connected to a connecting shaft 17 that extends along the axial direction L through the inner radial direction R1 of the reduction gear 30 and the hollow cylindrical rotor shaft 13. The connecting shaft 17 is connected to a first drive shaft DS1 that is driven and connected to the first wheel W1, which is the wheel on the first axial side L1.

[0034] The vehicle drive unit 10 includes a case 90 that houses a rotating electric machine MG and a gear mechanism 15. The case 90 comprises a first case section 91 and a second case section 92. The first case section 91 is formed in the shape of a bottomed cylinder opening to the second axial side L2. The second case section 92 is formed in the shape of a bottomed cylinder opening to the first axial side L1. In this embodiment, the first case section 91 and the second case section 92 are cylindrical, but they may also be polygonal cylinders.

[0035] In this embodiment, the first case portion 91 and the second case portion 92 are different components and are fixed to each other. Examples of fixing the first case portion 91 and the second case portion 92 include joining by bolting, brazing, riveting, welding, etc. In this embodiment, the first case portion 91 and the second case portion 92 are fastened together by bolts (not shown).

[0036] The joining position P1 between the first case portion 91 and the second case portion 92 is located axially on the first side L1 rather than at the end of the axial second side L2 of the rotating electric machine MG. In this embodiment, the joining position P1 between the first case portion 91 and the second case portion 92 is located axially on the first side L1 rather than at the center position of the axial direction L of the rotating electric machine MG.

[0037] The first case portion 91 rotatably supports the axial first side L1 portion of the connecting shaft 17 with respect to the rotor core 12a via the first bearing B1. In this embodiment, the first bearing B1 is a radial ball bearing.

[0038] The first case portion 91 forms at least a part of the first housing chamber E1 in which the rotating electric machine MG is housed. In this embodiment, the entire rotating electric machine MG and the coolant are housed in the first housing chamber E1. The first case portion 91 comprises a cylindrical first circumferential wall portion 91a and a first side wall portion 91b.

[0039] In this embodiment, the first side wall portion 91b and the first circumferential wall portion 91a are different members and are fixed to each other. Examples of fixing the first side wall portion 91b and the first circumferential wall portion 91a include fastening with bolts, brazing, riveting, welding, etc. In this embodiment, the first side wall portion 91b and the first circumferential wall portion 91a are fastened together with bolts (not shown).

[0040] The second case portion 92 forms at least a part of the second housing chamber E2 in which the gear mechanism 15 is housed. In this embodiment, the entire reduction gear 30 and lubricating oil are housed in the second housing chamber E2. The second case portion 92 is joined to the first case portion 91 from the second axial side L2. The second case portion 92 comprises a cylindrical second circumferential wall portion 92a and a second side wall portion 92b.

[0041] The second case portion 92 is positioned at a distance from the reduction gear 30. The second peripheral wall portion 92a is positioned at a distance from the reduction gear 30 and the differential gear device 40. In this embodiment, the second case portion 92 and the first ring gear RG1 are positioned at a distance from each other.

[0042] The first circumferential wall portion 91a is positioned along the axial direction L at the outer R2 of the radial direction R relative to the rotating electric machine MG. The first circumferential wall portion 91a is positioned to overlap with the rotating electric machine MG in a radial view along the radial direction R.

[0043] The second circumferential wall portion 92a is positioned along the axial direction L at a position radially spaced R away from the first circumferential wall portion 91a. The second circumferential wall portion 92a is positioned so as to overlap with the rotating electric machine MG in a radial view along the radial direction R. The second circumferential wall portion 92a is positioned along the axial direction L at a position R2 outside the radial direction R relative to the first circumferential wall portion 91a.

[0044] The first circumferential wall portion 91a is formed in a cylindrical shape having an axis along the axial direction L. The first circumferential wall portion 91a is positioned to cover the rotating electric machine MG from the outside R2 in the radial direction R. In this embodiment, the stator 11 is fixed to the first circumferential wall portion 91a. In the illustrated example, the stator core 11a is fastened to the first circumferential wall portion 91a with bolts.

[0045] The second circumferential wall portion 92a is formed in a cylindrical shape having an axis along the axial direction L. The second circumferential wall portion 92a is positioned to cover the gear mechanism 15 from the outside R2 in the radial direction R. The first circumferential wall portion 91a and the second circumferential wall portion 92a are positioned to overlap in a radial view along the radial direction R. In the illustrated example, the portion of the first circumferential wall portion 91a on the second axial side L2 and the portion of the second circumferential wall portion 92a on the first axial side L1 are positioned to overlap in a radial view.

[0046] The first side wall portion 91b is formed to extend along the radial direction R. The first side wall portion 91b is positioned to cover the rotating electric machine MG from the first axial direction L1. In this embodiment, the first side wall portion 91b is fixed to the first circumferential wall portion 91a from the first axial direction L1 so as to close the opening on the first axial direction L1 of the first circumferential wall portion 91a.

[0047] The second side wall portion 92b is formed to extend along the radial direction R. The second side wall portion 92b is positioned to cover the differential gear device 40 from the axial second side L2. In this embodiment, the second circumferential wall portion 92a and the second side wall portion 92b are integrally molded.

[0048] The case 90 includes an intermediate support portion 93. The intermediate support portion 93 is located between the rotating electric machine MG and the reduction gear 30 in the axial direction L. In this embodiment, the intermediate support portion 93 is located between the first housing chamber E1 and the second housing chamber E2. The intermediate support portion 93 is formed to extend along the radial direction R. The first ring gear RG1 is fixed to the intermediate support portion 93.

[0049] The intermediate support portion 93 includes a bearing retaining portion 94 that holds the third bearing B3. The portion of the rotor shaft 13 on the first axial side L1 relative to the rotor core 12a is rotatably supported against the first side wall portion 91b via the second bearing B2. The portion of the rotor shaft 13 on the second axial side L2 relative to the rotor core 12a is positioned to penetrate the intermediate support portion 93 in the axial direction L, and is rotatably supported by the intermediate support portion 93 via the third bearing B3. In this embodiment, the second bearing B2 and the third bearing B3 are radial ball bearings.

[0050] The intermediate support portion 93 includes a gear support portion 95 that supports the gear mechanism 15. In this embodiment, the gear support portion 95 rotatably supports a part of the gear mechanism 15 around an axis along the axial direction L. Alternatively, the gear support portion 95 may support a portion of the gear mechanism 15 that does not rotate around the axis along the axial direction L in a non-rotatable manner. In this embodiment, the first ring gear RG1 is fixed to the gear support portion 95.

[0051] In this embodiment, the portion of the carrier CR that is axially first L1 relative to the first planetary gear PG1 is rotatably supported by the gear support portion 95 via the fourth bearing B4. In this embodiment, the portion of the carrier CR that is axially second L2 relative to the second planetary gear PG2 is rotatably supported by the differential case 50 via the fifth bearing B5. In this embodiment, the fourth bearing B4 and the fifth bearing B5 are radial ball bearings.

[0052] The first member 51 of the differential case 50 supports the reduction gear 30 via the fifth bearing B5. In this embodiment, the first member 51 rotatably supports the carrier CR with respect to the first member 51 via the fifth bearing B5. The second member 52 of the differential case 50 is rotatably supported with respect to the second side wall portion 92b of the case 90 via the sixth bearing B6. In this embodiment, the sixth bearing B6 is a radial ball bearing.

[0053] The intermediate support portion 93 includes a fixing portion 96 that is fixed to at least one of the first case portion 91 and the second case portion 92. In this embodiment, the intermediate support portion 93 is spaced apart from the second case portion 92. In this embodiment, the fixing portion 96 is fixed to the first case portion 91.

[0054] In this embodiment, the intermediate support portion 93, the first case portion 91, and the second case portion 92 are different components. Examples of fixing the intermediate support portion 93 to at least one of the first case portion 91 and the second case portion 92 include fastening with bolts, brazing, crimping, welding, etc. In this embodiment, the intermediate support portion 93 and the first case portion 91 are fastened together with bolts.

[0055] The fixed portion 96 is positioned radially outward R2 relative to the bearing holding portion 94 and the gear support portion 95. The fixed portion 96 is positioned axially first side L1 relative to the third bearing B3. The fixed portion 96 is positioned radially outward R2 relative to the rotating electric machine MG, and overlaps with the rotating electric machine MG in a radial view along the radial direction R. The fixed portion 96 is positioned axially second side L2 relative to the joining position P1 between the first case portion 91 and the second case portion 92.

[0056] The intermediate support portion 93 includes a radially extending portion 93a that extends in the radial direction R. The bearing holding portion 94 is formed at the inner end R1 of the radially extending portion 93a in the radial direction R. The gear support portion 95 is formed at the inner end R1 of the radially extending portion 93a in the radial direction R.

[0057] The intermediate support portion 93 includes an axially extending portion 93b that extends in the axial direction L. The axially extending portion 93b is formed to extend from the outer end R2 in the radial direction R of the radially extending portion 93a toward the first axial side L1. The fixing portion 96 is formed at the end of the axially extending portion 93b toward the first axial side L1.

[0058] The fixing portion 96 is positioned so as to overlap with the stator 11 in a radial view along the radial direction R. Alternatively, the fixing portion 96 may be positioned so as to overlap with both the stator 11 and the rotor 12 in a radial view along the radial direction R.

[0059] The vehicle drive unit 10 is equipped with a rotation sensor S1 that detects the rotation of the rotor shaft 13. The rotation sensor S1 detects, for example, the rotation angle, rotation speed, etc., of the rotor shaft 13. Examples of the rotation sensor S1 include a resolver, a magnetic angle sensor, an inductive sensor, etc. The rotation sensor S1 is fixed to the intermediate support portion 93. In the illustrated example, the rotation sensor S1 is fastened to the radially extending portion 93a by bolts. In the illustrated example, the rotation sensor S1 detects an object to be detected attached to the rotor shaft 13.

[0060] The first side wall portion 91b is provided with a first through-hole 91c through which the connecting shaft 17 passes. An oil seal 97 is positioned between the connecting shaft 17 and the first through-hole 91c.

[0061] The second side wall portion 92b is provided with a second through-hole 92c through which an output member (a second bevel gear 63 in the illustrated example) passes. An oil seal 98 is positioned between the output member and the second through-hole 92c.

[0062] [Other Embodiments] Next, other embodiments of the vehicle drive system 10 will be described.

[0063] (1) In the above embodiment, the vehicle drive system 10 was described as having a configuration in which the rotating shafts of the rotating electric machine MG, the reduction gear 30, and the differential gear mechanism 60 are coaxial, and the reduction gear 30 uses a planetary gear mechanism. However, the invention is not limited to such an example, and for example, the reduction gear 30 may be a parallel-shaft type reduction gear using a counter gear or the like. Also, for example, the rotating shafts of the rotating electric machine MG and the differential gear mechanism 60 may be different, or the reduction gear 30 may have a three-shaft configuration with a third rotating shaft different from both the rotating shafts of the rotating electric machine MG and the differential gear mechanism 60. Also, for example, the intermediate support portion 93 may be provided with multiple holes through which shafts other than the rotor shaft 13 pass.

[0064] (2) In the above embodiment, a configuration in which both the reduction gear 30 and the differential gear 40 are housed in the case 90 was described as an example. However, the invention is not limited to such an example, and for example, one of the reduction gear 30 and the differential gear 40 may be housed in the case 90 and the other may be located outside the case 90.

[0065] (3) In the above embodiment, the fixed portion 96 was described as being located on the outer side R2 of the radial direction R with respect to the rotating electric machine MG, and in a position that overlaps with the rotating electric machine MG when viewed radially along the radial direction R. However, the invention is not limited to such an example, and for example, the fixed portion 96 may be located in a position that does not overlap with the rotating electric machine MG when viewed radially along the radial direction R.

[0066] (4) In the above embodiment, a configuration in which the intermediate support portion 93 is spaced apart from the second case portion 92 and the fixing portion 96 is fixed to the first case portion 91 was described as an example. However, the embodiment is not limited to such an example, and for example, the intermediate support portion 93 may be spaced apart from the first case portion 91 and the fixing portion 96 may be fixed to the second case portion 92.

[0067] (5) In the above embodiment, a configuration was described as in which the second circumferential wall portion 92a is positioned along the axial direction L at a distance R2 radially outward from the first circumferential wall portion 91a. However, the embodiment is not limited to such an example, and for example, the second circumferential wall portion 92a may be positioned along the axial direction L at a distance R1 radially inward from the first circumferential wall portion 91a. Also, for example, the intermediate support portion 93 may be positioned apart from both the first case portion 91 and the second case portion 92, and the fixing portion 96 may be fixed to a portion different from both the first case portion 91 and the second case portion 92 within the case 90. Also, for example, the fixing portion 96 of the intermediate support portion 93 may be fixed to both the first case portion 91 and the second case portion 92 such that it is sandwiched between both the first case portion 91 and the second case portion 92 in the axial direction L.

[0068] (6) In the above embodiment, a configuration was described as an example in which the first case portion 91 comprises a first circumferential wall portion 91a, the second case portion 92 comprises a second circumferential wall portion 92a, and the first circumferential wall portion 91a, the second circumferential wall portion 92a, and the rotating electric machine MG are arranged to overlap in a radial view along the radial direction R. However, the embodiment is not limited to such an example, and for example, the first circumferential wall portion 91a or the second circumferential wall portion 92a and the rotating electric machine MG may be arranged not to overlap in a radial view along the radial direction R. Also, for example, the second circumferential wall portion 92a may be arranged to be in contact with the first circumferential wall portion 91a.

[0069] (7) In the above embodiment, a configuration in which the first circumferential wall portion 91a and the first side wall portion 91b are fastened together by bolts, and the second circumferential wall portion 92a and the second side wall portion 92b are integrally molded was described as an example. However, the invention is not limited to such an example, for example, the first circumferential wall portion 91a and the first side wall portion 91b may be integrally molded, and the second circumferential wall portion 92a and the second side wall portion 92b may be fastened together by bolts. Also, for example, the first case portion 91 may be a cylindrical member that does not have the first side wall portion 91b. Also, for example, the second case portion 92 may be a cylindrical member that does not have the second side wall portion 92b.

[0070] (8) In the above embodiment, a configuration in which the vehicle drive unit 10 is equipped with first bearings B1 to sixth bearings B6 which are radial ball bearings was described as an example. However, the vehicle drive unit 10 is not limited to such an example, and for example, any or all of the first bearings B1 to sixth bearings B6 may be radial roller bearings. Also, for example, the vehicle drive unit 10 may be equipped with no second bearing B2.

[0071] (9) The configurations disclosed in the embodiments described above can be applied in combination with configurations disclosed in other embodiments, as long as no inconsistencies arise. With regard to other configurations, the embodiments disclosed herein are merely illustrative in all respects. Therefore, various modifications can be made as appropriate without departing from the spirit of this disclosure.

[0072] [Summary of the above embodiments] The following describes the vehicle drive system related to this disclosure.

[0073] In one embodiment, the vehicle drive system (10) comprises a rotating electric machine (MG) equipped with a rotor (12), an output member (spline engagement portion 63d) that is driven and connected to the wheels (first wheel W1, second wheel W2), a gear mechanism (15) that transmits driving force between the rotating electric machine (MG) and the output member (spline engagement portion 63d), and a case (90) that houses the rotating electric machine (MG) and the gear mechanism (15), wherein the case (90) is the rotating electric machine (MG) The rotor (12) comprises a first case portion (91) that forms at least a part of the first housing chamber (E1) in which the rotor (12) is housed, a second case portion (92) that forms at least a part of the second housing chamber (E2) in which the gear mechanism (15) is housed, and an intermediate support portion (93) disposed between the first housing chamber (E1) and the second housing chamber (E2), wherein the direction along the rotation axis (A1) of the rotor (12) is defined as the axial direction (L), and one side of the axial direction (L) is defined as the first axial side (L1), and the axis With the other side of direction L designated as the second axial side (L2), and the direction perpendicular to the rotation axis (A1) designated as the radial direction (R), the gear mechanism (15) is positioned on the second axial side (L2) relative to the rotor (12) on the rotation axis (A1), and a rotor bearing (third bearing B3) is positioned between the rotor (12) and the gear mechanism (15) in the axial direction (L), rotatably supporting the rotor shaft (13) which rotates integrally with the rotor (12), and the intermediate support portion (93) is The device comprises a bearing retaining portion (94) that holds the rotor bearing (third bearing B3), a gear support portion (95) that supports the gear mechanism (15), and a fixing portion (96) fixed to at least one of the first case portion (91) and the second case portion (92), wherein the fixing portion (96) is located radially (R) outward (R2) from the bearing retaining portion (94) and the gear support portion (95) and is positioned axially first (L1) further than the rotor bearing (third bearing B3).

[0074] In this configuration, the fixing portion (96) fixed to the case (90) in the intermediate support portion (93) is located radially (R) outward (R2) from the bearing holding portion (94) and the gear support portion (95), and is positioned axially first (L1) further than the rotor bearing (third bearing B3). As a result, the vibration transmission path from the bearing holding portion (94) and the gear support portion (95) to the fixing portion (96) tends to be longer. Therefore, vibrations from the gear mechanism (15), etc., can be attenuated and transmitted to the outer wall of the case (90). This makes it easier to reduce the noise emitted from the case (90) to the outside due to vibrations of the gear mechanism (15).

[0075] In one embodiment, the fixed portion (96) is located radially (R) outward (R2) from the rotating electric machine (MG) and is positioned in a location that overlaps with the rotating electric machine (MG) in a radial view along the radial direction (R).

[0076] This configuration makes it easier to ensure a long vibration transmission path from the bearing holder (94) and gear support (95) to the fixed part (96).

[0077] In one embodiment, the intermediate support portion (93) is spaced apart from the second case portion (92), and the fixing portion (96) is fixed to the first case portion (91).

[0078] This configuration prevents direct transmission of vibrations from the intermediate support (93) to the second case (92). Furthermore, because the fixed part (96) is located radially (R) outward (R2) from the bearing holder (94) and gear support (95) and axially (L1) further to the first side (L1) than the rotor bearing (third bearing B3), a longer vibration transmission path is ensured from the bearing holder (94) and gear support (95) to the first case (91). Consequently, vibrations from the gear mechanism (15) and the rotating electric machine MG can be attenuated and transmitted to the outer wall of the case (90). This reduces the amount of noise emitted from the case (90) to the outside due to vibrations from the gear mechanism (15) and the like.

[0079] In one embodiment, the first case portion (91) comprises a cylindrical first circumferential wall portion (91a) arranged along the axial direction (L) on the radially (R) outer side (R2) with respect to the rotating electric machine (MG), and the second case portion (92) comprises a cylindrical second circumferential wall portion (92a) arranged along the axial direction (L) at a position spaced radially (R) apart from the first circumferential wall portion (91a), and the first circumferential wall portion (91a), the second circumferential wall portion (92a), and the rotating electric machine (MG) are arranged to overlap in a radial view along the radial direction (R).

[0080] With this configuration, the radially (R) outer side (R2) of the rotating electric machine (MG) can be covered by the first circumferential wall (91a) and the second circumferential wall (92a), thereby reducing the amount of sound radiated to the outside from the case (90) due to vibrations of the rotating electric machine (MG).

[0081] The vehicle drive system relating to this disclosure only needs to be able to achieve at least one of the effects described above. [Explanation of Symbols]

[0082] 8: Vehicle, 10: Vehicle drive unit, 12: Rotor, 13: Rotor shaft, 15: Gear mechanism, 63d: Spline engagement part (output member), 90: Case, 91: First case section, 91a: First peripheral wall section, 92: Second case section, 92a: Second peripheral wall section, 93: Intermediate support section, 94: Bearing holder section, 95: Gear support section, 96: Fixed section, A1: Rotating axis, B3: Third bearing (rotor bearing), E1: First housing chamber, E2: Second housing chamber, MG: Rotating electric machine, W1: First wheel (wheel), W2: Second wheel (wheel)

Claims

1. A rotating electric machine equipped with a rotor, An output member that is driven and connected to the wheel, A gear mechanism that transmits driving force between the rotating electric machine and the output member, The rotating electric machine and the gear mechanism are housed in a case, The case comprises a first case portion that forms at least a part of a first housing chamber in which the rotating electric machine is housed, a second case portion that forms at least a part of a second housing chamber in which the gear mechanism is housed, and an intermediate support portion disposed between the first housing chamber and the second housing chamber. The direction along the rotation axis of the rotor is defined as the axial direction, one side in the axial direction is defined as the axial first side, the other side in the axial direction is defined as the axial second side, and the direction perpendicular to the rotation axis is defined as the radial direction. On the rotation axis, the gear mechanism is positioned on the second axial side relative to the rotor. A rotor bearing is positioned between the rotor and the gear mechanism in the axial direction, rotatably supporting the rotor shaft which rotates integrally with the rotor. The intermediate support portion comprises a bearing holding portion for holding the rotor bearing, a gear support portion for supporting the gear mechanism, and a fixing portion fixed to at least one of the first case portion and the second case portion. The fixed portion is located radially outward from the bearing holding portion and the gear support portion, and is positioned axially on the first side of the rotor bearing, in a vehicle drive device.

2. The vehicle drive device according to claim 1, wherein the fixed portion is located radially outward with respect to the rotating electric machine and is positioned in a position that overlaps with the rotating electric machine when viewed radially along the radial direction.

3. The aforementioned intermediate support portion is spaced apart from the second case portion. The vehicle drive device according to claim 1, wherein the fixed portion is fixed to the first case portion.

4. The first case portion comprises a cylindrical first circumferential wall portion arranged radially outward from the rotating electric machine and along the axial direction, The second case portion comprises a cylindrical second circumferential wall portion arranged along the axial direction at a position radially separated from the first circumferential wall portion, The vehicle drive device according to any one of claims 1 to 3, wherein the first peripheral wall portion, the second peripheral wall portion, and the rotating electric machine are arranged to overlap in a radial view along the radial direction.

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