Vehicle drive device

Abstract

To achieve a technique capable of appropriately supplying oil to each of oil holes formed at a plurality of positions in an axial direction in a rotor shaft even when an oil passage for supplying oil to the oil holes formed in the rotor shaft is not formed in a shaft member arranged in an internal space of the rotor shaft or when the shaft member is not arranged in the internal space of the rotor shaft.SOLUTION: The vehicle drive device includes an oil supply unit that supplies oil to the rotor shaft 70. The oil supplying portion is configured to supply oil to the internal space S of the rotor shaft 70 on the axial first side L1 with respect to the rotor. The rotor shaft 70 includes oil holes that allow the internal space S and the outer peripheral surface of the rotor shaft 70 to communicate with each other at a plurality of positions in the axial direction L on the side L2 on the second side in the axial direction with respect to the oil supplying portion. A plurality of recessed grooves 10 extending in the axial direction L are formed on the inner peripheral surface of the rotor shaft 70, and the plurality of recessed grooves 10 include a plurality of connection recessed grooves 11 connected to different oil holes.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a vehicle drive device that includes an output member that is drivingly connected to a wheel, a rotating electric machine that has a rotor, a cylindrical rotor shaft that rotates integrally with the rotor, a power transmission mechanism that transmits power between the rotor shaft and the output member, and an oil supply unit. [Background technology]

[0002] An example of such a vehicle drive device is disclosed in Japanese Patent Laid-Open Publication No. 2023-152666 (Patent Document 1). Hereinafter, in the description of the background art, the reference numerals in parentheses refer to those in Patent Document 1. The vehicle drive device of Patent Document 1 includes two shaft members (71, 72) each drivingly connected to a wheel (W), a cylindrical input member (2) that rotates integrally with a rotor (12) of a rotating electric machine (1), a planetary gear mechanism (3) and a differential gear device (4) that transmit power between the input member (2) and the two shaft members (71, 72), and an oil supply unit (8).

[0003] The first shaft member (71), which is one of the two shaft members (71, 72), includes an output shaft member (711) arranged to extend in the axial direction (L) within the internal space of the input member (2). An in-shaft oil passage (P2), to which oil is supplied from the oil supply unit (8), is formed inside the output shaft member (711) and extends in the axial direction (L). Furthermore, oil holes communicating between the inner and outer peripheral surfaces of the input member (2) are formed at a plurality of locations in the axial direction (L) in the input member (2). The oil in the in-shaft oil passage (P2) flows between the outer peripheral surface of the output shaft member (711) and the inner peripheral surface of the input member (2) in the radial direction (R) through an oil passage communicating between the in-shaft oil passage (P2) and the outer peripheral surface of the output shaft member (711), and is then supplied to the oil holes formed in the input member (2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2023-152666 Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, the vehicle drive device of Patent Document 1 is configured such that an oil passage through which oil is supplied from an oil supply unit is formed in a shaft member (an output shaft member in Patent Document 1) disposed in the internal space of a rotor shaft (an input member in Patent Document 1) that rotates integrally with the rotor, and the oil is supplied from the oil passage to oil holes formed in the rotor shaft at multiple locations in the axial direction. Alternatively, it is conceivable that an oil passage for supplying oil to the oil holes formed in the rotor shaft is not formed in the shaft member disposed in the internal space of the rotor shaft. For example, it is conceivable to configure the oil supplied from the oil supply unit to flow toward one side in the axial direction through the internal space of the rotor shaft, regardless of whether a shaft member is disposed in the internal space of the rotor shaft. However, in this case, there are cases in which it is difficult to appropriately supply oil to each of the multiple oil holes, for example, because centrifugal force caused by rotation of the rotor shaft causes too much oil to be supplied to the oil holes closer to the oil supply unit, resulting in an insufficient amount of oil to the oil holes farther from the oil supply unit.

[0006] Therefore, it is desirable to realize a technology that can appropriately supply oil to each of the oil holes formed at multiple axial locations on the rotor shaft, even if the shaft member placed in the internal space of the rotor shaft does not have an oil passage for supplying oil to the oil holes formed in the rotor shaft, or even if no shaft member is placed in the internal space of the rotor shaft. [Means for solving the problem]

[0007] The vehicle drive device of the present disclosure is a vehicle drive device comprising: an output member drivingly connected to a wheel; a rotating electric machine having a rotor; a cylindrical rotor shaft rotating integrally with the rotor; a power transmission mechanism for transmitting power between the rotor shaft and the output member; and an oil supply unit for supplying oil to the rotor shaft, wherein the direction along the rotational 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, and the oil supply unit is configured to supply oil to the internal space of the rotor shaft on the axial first side relative to the rotor, the rotor shaft has oil holes connecting the internal space and the outer peripheral surface of the rotor shaft at multiple locations in the axial direction on the second axial side of the oil supply unit, and a plurality of grooves extending in the axial direction are formed on the inner peripheral surface of the rotor shaft, and the multiple grooves include a plurality of connecting grooves connected to different oil holes.

[0008] According to this configuration, oil supplied by the oil supply unit into the internal space of the rotor shaft can be supplied toward the second axial side and to each of the oil holes provided at multiple axial locations on the second axial side of the oil supply unit. During this process, centrifugal force accompanying rotation of the rotor shaft acts on the oil present in the internal space, pushing it toward the inner circumferential surface of the rotor shaft, where multiple connecting grooves connected to different oil holes are formed. Therefore, oil supplied by the oil supply unit into the internal space of the rotor shaft can be divided and circulated among the multiple connecting grooves connected to different oil holes. This reduces the likelihood of an excessive supply of oil to the oil holes on the first axial side, which is closer to the oil supply unit, resulting in an insufficient supply of oil to the oil holes on the second axial side, which is farther from the oil supply unit. This allows oil to be appropriately supplied to each of the oil holes provided at multiple axial locations.

[0009] As described above, with this configuration, even if an oil passage for supplying oil to the oil holes formed in the rotor shaft is not formed in the shaft member placed in the internal space of the rotor shaft, or even if a shaft member is not placed in the internal space of the rotor shaft, it is possible to appropriately supply oil to each of the oil holes formed at multiple locations in the axial direction of the rotor shaft.

[0010] Further features and advantages of the vehicle drive system will become apparent from the following description of the embodiments, which is given with reference to the drawings. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a skeleton diagram of a vehicle drive device according to an embodiment; [Figure 2] 1 is a cross-sectional view of a portion of a vehicle drive device according to an embodiment; [Figure 3] Cross-sectional view of a rotor shaft according to an embodiment. [Figure 4] FIG. 3 is a diagram showing oil passages formed in the internal spaces of the rotor shaft and the connecting shaft in FIG. 2. [Figure 5] FIG. 1 is a perspective view of an oil passage formed in an internal space of a rotor shaft and a connecting shaft according to an embodiment; [Figure 6] 1 is an axial view of an oil passage formed in an internal space of a rotor shaft according to an embodiment; [Figure 7] FIG. 10 is a diagram showing a part of an oil passage formed in an internal space of a rotor shaft according to an embodiment; [Figure 8] FIG. 10 is a diagram showing a part of an oil passage formed in an internal space of a rotor shaft according to another embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0012] An embodiment of a vehicle drive device will be described with reference to the drawings. In this embodiment, the first groove 10 corresponds to the "groove", the first connecting groove 11 corresponds to the "connecting groove", and the first non-connecting groove 12 corresponds to the "non-connecting groove".

[0013] In this specification, the term "driving connection" refers to a state in which two rotating elements are connected to each other so as to be able to transmit a driving force, and includes a state in which the two rotating elements are connected to rotate integrally, or a state in which the two rotating elements are connected to each other so as to be able to transmit a 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, and chains. Note that 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 the term "driving connection" is used to refer to each rotating element of a planetary gear mechanism, it refers to a state in which the rotating elements are connected to each other without passing through other rotating elements of the planetary gear mechanism.

[0014] In addition, in this specification, the term "rotating electric machine" is used as a concept that includes motors (electric motors), generators (electric generators), and motor-generators that function as both motors and generators as needed.

[0015] As shown in FIG. 1, the vehicle drive system 100 includes an output member 30 drivingly connected to a wheel W, a rotating electric machine 5 including a rotor 50, a cylindrical rotor shaft 70 that rotates integrally with the rotor 50, and a power transmission mechanism 1 that transmits power between the rotor shaft 70 and the output member 30. The vehicle drive system 100 further includes a case 9 that houses the rotating electric machine 5 and the power transmission mechanism 1. The rotating electric machine 5 includes a stator 51 in addition to the rotor 50, and the rotor 50 is supported by the case 9 so as to be rotatable relative to the stator 51. The vehicle drive system 100 transmits the driving force of the rotating electric machine 5 to the wheel W to run the vehicle (a vehicle equipped with the vehicle drive system 100). Note that the vehicle may be provided with a driving force source (for example, an internal combustion engine) separate from the rotating electric machine 5, and the vehicle drive system 100 may be configured to transmit the driving force of the separate driving force source to the wheel W as well.

[0016] The rotating electric machine 5 is electrically connected to an electricity storage device such as a battery or a capacitor. The rotating electric machine 5 is electrically connected to the electricity storage device, for example, via an inverter. The rotating electric machine 5 generates driving force by powering using the electric power stored in the electricity storage device. The rotating electric machine 5 also generates electricity using driving force transmitted to the rotating electric machine 5 (for example, driving force transmitted from the wheels W), thereby charging the electricity storage device.

[0017] The rotor 50 includes a rotor core 50a fixed to the rotor shaft 70. If the rotating electric machine 5 is a permanent magnet type, a permanent magnet is provided in the rotor core 50a, and if the rotating electric machine 5 is a wound field type, a coil (rotor coil) is wound around the rotor core 50a. The stator 51 includes a stator core 51a fixed to the case 9, and a coil (stator coil) wound around the stator core 51a. A portion of the coil protruding from the stator core 51a forms a coil end portion 51b.

[0018] The power transmission mechanism 1 includes a transmission shaft and gears, and may also include engaging elements such as a clutch and a brake. In this embodiment, the power transmission mechanism 1 is configured to transmit driving force between a rotor shaft 70 and multiple output members 30. Specifically, the vehicle drive device 100 includes, as the output members 30, a first output member 31 drivingly connected to a first wheel W1 and a second output member 32 drivingly connected to a second wheel W2. The first wheel W1 and the second wheel W2 are a pair of left and right wheels W. The power transmission mechanism 1 is configured to transmit driving force between the rotor shaft 70 and two output members 30 (specifically, the first output member 31 and the second output member 32). Note that the power transmission mechanism 1 may also be configured to transmit driving force between the rotor shaft 70 and one output member 30.

[0019] 1 and other figures, the direction along the rotational axis A of the rotor 50 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. Furthermore, the direction perpendicular to the rotational axis A is defined as the radial direction R, the inside of the radial direction R (the side approaching the rotational axis A) is defined as the inner radial direction R1, and the outside of the radial direction R (the side away from the rotational axis A) is defined as the outer radial direction R2. Furthermore, as shown in FIGS. 5 and 6, the direction going around the rotational axis A is defined as the circumferential direction C.

[0020] In this embodiment, the power transmission mechanism 1 includes a planetary gear mechanism 3 and a differential gear mechanism 4. The planetary gear mechanism 3 and the differential gear mechanism 4 are arranged on the rotation axis A. As described above, in this embodiment, the elements of the power transmission mechanism 1 are arranged on the rotation axis A. However, the elements of the power transmission mechanism 1 may be arranged separately on multiple axes (e.g., two or three axes) including the rotation axis A. In this case, for example, the differential gear mechanism 4 is arranged on an axis different from the rotation axis A. Furthermore, when the elements of the power transmission mechanism 1 are arranged separately on three axes, namely the rotation axis A, the first axis, and the second axis, for example, the differential gear mechanism 4 is arranged on the first axis, and the counter gear mechanism is arranged on the second axis.

[0021] The planetary gear mechanism 3 and the differential gear mechanism 4 are disposed on the second axial side L2 with respect to the rotor 50. That is, the power transmission mechanism 1 includes a gear mechanism 2 disposed on the second axial side L2 with respect to the rotor 50, and in this embodiment, the gear mechanism 2 includes the planetary gear mechanism 3 and the differential gear mechanism 4. The differential gear mechanism 4 is disposed on the second axial side L2 with respect to the planetary gear mechanism 3.

[0022] The planetary gear mechanism 3 can be a planetary gear mechanism of any structure, such as a single pinion type or a double pinion type. In this embodiment, the planetary gear mechanism 3 is configured to reduce the rotation of the rotor 50 and transmit it to the differential gear mechanism 4. In the example shown in FIGS. 1 and 2 , the planetary gear mechanism 3 includes a sun gear SG, a carrier CR, a first ring gear RG1, and a second ring gear RG2. The sun gear SG is drivingly connected to a rotor shaft 70. Here, the sun gear SG is connected to the rotor shaft 70 so as to rotate integrally with the rotor shaft 70. The first ring gear RG1 is fixed to a case 9, and the second ring gear RG2 is supported by the case 9 so as to be rotatable relative to the case 9. The second ring gear RG2 is drivingly connected to a differential case 40, which will be described later. Here, the second ring gear RG2 is connected to the differential case 40 so as to rotate integrally with the differential case 40. The carrier CR rotatably supports a first pinion gear PG1 and a second pinion gear PG2 that rotate integrally with each other. The first pinion gear PG1 meshes with the sun gear SG and the first ring gear RG1, and the second pinion gear PG2 meshes with the second ring gear RG2.

[0023] The differential gear mechanism 4 can be a differential gear mechanism of any structure, such as a bevel gear type or a planetary gear type. In the example shown in FIGS. 1 and 2 , the differential gear mechanism 4 includes a differential case 40, a first side gear 41, a second side gear 42, a pinion shaft 43, and a pinion gear 44. The differential case 40 is configured to rotate about a rotation axis A. The pinion gear 44 is supported by the pinion shaft 43 that rotates integrally with the differential case 40, and rotates (spins) about the axis of the pinion shaft 43 and also rotates (revolves) about the rotation axis A. The first side gear 41 and the second side gear 42 mesh with the pinion gear 44 and rotate about the rotation axis A. The first side gear 41 is disposed on a first axial side L1 relative to the pinion shaft 43, and the second side gear 42 is disposed on a second axial side L2 relative to the pinion shaft 43.

[0024] The first side gear 41 is drivingly connected to the first output member 31, and the second side gear 42 is drivingly connected to the second output member 32. Here, the first side gear 41 is connected to the first output member 31 so as to rotate integrally therewith, and the second side gear 42 is connected to the second output member 32 so as to rotate integrally therewith. In this embodiment, the first side gear 41 is formed integrally with the first output member 31, and the second side gear 42 is formed integrally with the second output member 32.

[0025] In this embodiment, the vehicle on which the vehicle drive device 100 is mounted is provided with a first drive shaft DS1 drivingly connected to a first wheel W1 and a second drive shaft DS2 drivingly connected to a second wheel W2. The drive shafts (DS1, DS2) are connected to the wheels W via, for example, constant velocity joints. The first output member 31 is connected to the first drive shaft DS1 so as to rotate integrally with the first drive shaft DS1, and the second output member 32 is connected to the second drive shaft DS2 so as to rotate integrally with the second drive shaft DS2.

[0026] In the present embodiment, the power transmission mechanism 1 includes a shaft member 71 disposed to extend in the axial direction L in the internal space S (see FIG. 3 ) of the rotor shaft 70. The first output member 31 is coupled to the first drive shaft DS1 via the shaft member 71. Specifically, a coupling portion (here, a spline coupling portion) with the first drive shaft DS1 is formed at an end of the shaft member 71 on the first axial side L1, and a coupling portion (here, a spline coupling portion) with the first output member 31 is formed at an end of the shaft member 71 on the second axial side L2. As such, in the present embodiment, the shaft member 71, rather than the member on which the first side gear 41 is formed, is provided with the coupling portion with the first drive shaft DS1. Therefore, the shaft member 71 (or the coupling portion of the shaft member 71 with the first drive shaft DS1) may be referred to as the “output member” (the “first output member” in the present embodiment) rather than the member on which the first side gear 41 is formed.

[0027] In this embodiment, the power transmission mechanism 1 includes a connecting shaft 72 that is connected to the rotor shaft 70 so as to extend from the rotor shaft 70 toward the second axial side L2. A gear (here, a sun gear SG) that rotates integrally with the rotor shaft 70 is formed on the connecting shaft 72. The connecting shaft 72 is connected to the rotor shaft 70 so as to rotate integrally with the rotor shaft 70. In this embodiment, the connecting shaft 72 is connected to the rotor shaft 70 by welding. The connecting shaft 72 may also be connected to the rotor shaft 70 by a connection other than welding, such as a spline connection.

[0028] The rotor shaft 70 is formed in a cylindrical shape that is open on at least one side in the axial direction L. In this embodiment, the rotor shaft 70 is formed in a cylindrical shape that is open on both sides in the axial direction L. Here, the rotor shaft 70 is formed in a cylindrical shape over the entire axial direction L. The connecting shaft 72 is formed in a cylindrical shape that is open on at least one side in the axial direction L. In this embodiment, the connecting shaft 72 is formed in a cylindrical shape that is open on both sides in the axial direction L. Here, the connecting shaft 72 is formed in a cylindrical shape over the entire axial direction L. In this embodiment, the diameter of the inner circumferential surface of the connecting shaft 72 is set to be the same as (the same as or approximately the same as) the diameter of the inner circumferential surface of the rotor shaft 70.

[0029] The shaft member 71 is disposed in at least a portion of the internal space S of the rotor shaft 70 in the axial direction L. In the present embodiment, the shaft member 71 is disposed over the entire area of ​​the internal space S of the rotor shaft 70 in the axial direction L. Specifically, the shaft member 71 is disposed so as to penetrate the rotor shaft 70 in the axial direction L. In the present embodiment, the shaft member 71 is further disposed so as to penetrate a connecting shaft 72 connected to the rotor shaft 70 in the axial direction L. A coupling portion with the first drive shaft DS1 is formed in a portion of the shaft member 71 disposed on a first axial side L1 with respect to the rotor shaft 70. In addition, a coupling portion with the first output member 31 is formed in a portion of the shaft member 71 disposed on a second axial side L2 with respect to the rotor shaft 70 (in the present embodiment, a portion disposed on the second axial side L2 with respect to the connecting shaft 72).

[0030] In this embodiment, at least a portion of the shaft member 71 that is disposed in the internal space S of the rotor shaft 70 is formed in a columnar (solid) shape. In the example shown in FIG. 2 , a portion of the shaft member 71 that is disposed in the internal space S of the connecting shaft 72 and a portion of the shaft member 71 that is disposed on the second axial side L2 of the connecting shaft 72 (specifically, the connection portion with the first output member 31) are also formed in a columnar shape. On the other hand, a portion of the shaft member 71 that is disposed on the first axial side L1 of the rotor shaft 70 (specifically, the connection portion with the first drive shaft DS1) is formed in a cylindrical (hollow) shape. Note that the portion of the shaft member 71 that is disposed on the second axial side L2 of the connecting shaft 72 may be formed in a cylindrical shape. Furthermore, the shaft member 71 may be formed in a columnar shape over the entire axial direction L, or may be formed in a cylindrical shape over the entire axial direction L.

[0031] The outer circumferential surface of the shaft member 71 is formed with a smaller diameter than the inner circumferential surface of the rotor shaft 70, and a first cylindrical space S1, which is a cylindrical space centered on the rotation axis A, is formed between the outer circumferential surface of the shaft member 71 and the inner circumferential surface of the rotor shaft 70. The outer circumferential surface of the shaft member 71 is formed with a smaller diameter than the inner circumferential surface of the connecting shaft 72, and a second cylindrical space S2, which is a cylindrical space centered on the rotation axis A, is formed between the outer circumferential surface of the shaft member 71 and the inner circumferential surface of the connecting shaft 72. In this embodiment, the diameter of the outer circumferential surface of the portion of the shaft member 71 that is disposed in the internal space S of the rotor shaft 70 is set to be equal to (the same as or approximately the same as) the diameter of the outer circumferential surface of the portion of the shaft member 71 that is disposed in the internal space S of the connecting shaft 72.

[0032] As shown in FIG. 2, the vehicle drive device 100 includes a first bearing B1, a second bearing B2, a third bearing B3, a fourth bearing B4, and a fifth bearing B5. The first bearing B1 rotatably supports a portion of the shaft member 71 located on a first axial side L1 relative to the rotor shaft 70 relative to the case 9 (here, a shaft end wall located at the end in the axial direction L). The second bearing B2 rotatably supports a portion of the rotor shaft 70 located on the first axial side L1 relative to the rotor core 50a relative to the case 9 (here, the shaft end wall). The third bearing B3 rotatably supports a portion of the rotor shaft 70 located on a second axial side L2 relative to the rotor core 50a relative to the case 9 (here, an intermediate wall located in the intermediate portion in the axial direction L). The fourth bearing B4 rotatably supports a portion of the carrier CR located on the first axial side L1 relative to the pinion gears (PG1, PG2) relative to the case 9 (here, the intermediate wall). The fifth bearing B5 rotatably supports the differential case 40 a portion of the carrier CR that is disposed on the second axial side L2 with respect to the pinion gears (PG1, PG2).

[0033] As shown in FIG. 2 , the rotor shaft 70 has oil holes 60, which communicate between the internal space S of the rotor shaft 70 and the outer circumferential surface of the rotor shaft 70, at multiple locations in the axial direction L on a second axial side L2 relative to an oil supply unit 6 (described later). Some of the oil holes 60 may be located closer to the first axial side L1 relative to the oil supply unit 6, but in this embodiment, all of the oil holes 60 are located closer to the second axial side L2 relative to the oil supply unit 6. The oil holes 60 are formed to penetrate the rotor shaft 70 in the radial direction R. The oil holes 60 may extend along the radial direction R or may extend in a direction inclined relative to the radial direction R. In this embodiment, the oil holes 60 extend along the radial direction R. Furthermore, one oil hole 60 may be located at the same position in the axial direction L, or multiple oil holes 60 may be located at different positions in the circumferential direction C. In this embodiment, two oil holes 60 are located at the same position in the axial direction L but 180 degrees apart relative to the rotation axis A.

[0034] As shown in FIG. 2 , in this embodiment, the rotor shaft 70 is provided with oil holes 60 at four locations in the axial direction L on the second axial side L2 of the oil supply portion 6. Here, the oil holes 60 provided at the four locations in the axial direction L are referred to as a first oil hole 61, a second oil hole 62, a third oil hole 63, and a fourth oil hole 64, in that order from the first axial side L1. In FIG. 2 , the first oil hole 61, the second oil hole 62, the third oil hole 63, a fifth oil hole 65 (described later), and a sixth oil hole 66 (described later), which do not appear in the cross section of FIG. 2 , are shown by imaginary lines. In this embodiment, the oil holes 60 are disposed at different positions in the circumferential direction C from the oil holes 60 provided at other locations in the axial direction L. Therefore, as shown in FIG. 6 , the first oil hole 61, the second oil hole 62, the third oil hole 63, and the fourth oil hole 64 are disposed at different positions in the circumferential direction C. Note that in FIG. 4 to FIG. 8 , including FIG. 6 , the oil passages are shown in isolation.

[0035] A plurality of first grooves 10 extending in the axial direction L are formed on the inner peripheral surface of the rotor shaft 70. The first grooves 10 are formed so as to extend at least in the axial direction L. As shown in FIG. 3 , in this embodiment, each of the plurality of first grooves 10 is formed so as to extend parallel to the axial direction L. The first grooves 10 are formed so as to be recessed from the inner peripheral surface of the rotor shaft 70 toward the radially outward direction R2. Therefore, as shown in FIGS. 4 to 6 , the first cylindrical space S1 formed between the outer peripheral surface of the shaft member 71 and the inner peripheral surface of the rotor shaft 70 expands toward the radially outward direction R2 at the locations where the first grooves 10 are formed. Note that in FIGS. 5 and 6 , a first connecting groove 11 and a first non-connecting groove 12, which will be described later, correspond to the first grooves 10. The size of the gap in the radial direction R between the outer peripheral surface of the shaft member 71 and a reference inner peripheral surface, which is a portion of the inner peripheral surface of the rotor shaft 70 where the first grooves 10 are not formed, is set to be smaller than the depth of the deepest part of the first grooves 10 (the depth from the reference inner peripheral surface). The cross-sectional shape of the first grooves 10 can be various shapes such as a U-shape, a semicircular shape, a V-shape, a rectangular shape, etc.

[0036] The plurality of first grooves 10 includes a plurality of first connection grooves 11 connected to different oil holes 60. One first connection groove 11 may be connected to a plurality of oil holes 60, but a plurality of first connection grooves 11 are not connected to the same oil hole 60. In this embodiment, one first connection groove 11 is connected to a single oil hole 60. Therefore, the plurality of first grooves 10 includes a first connection groove 11 connected to a first oil hole 61, a first connection groove 11 connected to a second oil hole 62, a first connection groove 11 connected to a third oil hole 63, and a first connection groove 11 connected to a fourth oil hole 64. In this embodiment, two of each of these four types of first connection grooves 11 are formed on the inner circumferential surface of the rotor shaft 70 (see FIG. 6 ).

[0037] The first connection groove 11 is formed to extend in the axial direction L to the formation position of the destination oil hole 60. In the present embodiment, the first connection groove 11 is formed to extend in the axial direction L from the end of the rotor shaft 70 on the first axial side L1 to the formation position of the destination oil hole 60. In the present embodiment, the first connection groove 11 is formed to have a uniform depth over the entire area in the axial direction L. Therefore, as shown in FIG. 7 , the depth of the connection portion 11a connected to the oil hole 60 (here, the first oil hole 61) is set to be the same as the depth of the other portion (specifically, the portion closer to the first axial side L1 than the connection portion 11a).

[0038] In this embodiment, the multiple first grooves 10 include a first non-connection groove 12 that extends in the axial direction L to the end of the rotor shaft 70 on the second axial side L2 without being connected to the oil hole 60. Here, four first non-connection grooves 12 are formed on the inner circumferential surface of the rotor shaft 70 at equal intervals in the circumferential direction C, with the phases shifted by 90 degrees. In this embodiment, the first non-connection groove 12 is formed so as to extend in the axial direction L from the end of the rotor shaft 70 on the first axial side L1 to the end of the rotor shaft 70 on the second axial side L2.

[0039] The multiple first grooves 10 may be arranged at equal intervals in the circumferential direction C, or may be arranged at unequal intervals in the circumferential direction C. In this embodiment, the multiple first grooves 10 are arranged at equal intervals in the circumferential direction C. Specifically, as shown in FIG. 6 , 12 first grooves 10 including eight first connection grooves 11 and four first non-connection grooves 12 are arranged at equal intervals in the circumferential direction C with a phase shift of 30 degrees.

[0040] As shown in Figures 3 to 5, in this embodiment, a first circumferential groove 13 extending in the circumferential direction C is formed in the end of the inner peripheral surface of the rotor shaft 70 on the first axial side L1. The first circumferential groove 13 is formed so as to be recessed from the inner peripheral surface of the rotor shaft 70 toward the radially outer side R2. The first circumferential groove 13 is formed over the entire area in the circumferential direction C. Therefore, the multiple first recessed grooves 10 communicate with each other in the circumferential direction C via the first circumferential groove 13 at the end of the rotor shaft 70 on the first axial side L1.

[0041] 3 to 5, in this embodiment, a second circumferential groove 14 extending in the circumferential direction C is formed in the end portion of the inner peripheral surface of the rotor shaft 70 on the second axial side L2. The second circumferential groove 14 is formed so as to be recessed from the inner peripheral surface of the rotor shaft 70 toward the radially outer side R2. The second circumferential groove 14 is formed over the entire area in the circumferential direction C. Therefore, the multiple first non-connection recessed grooves 12 communicate with each other in the circumferential direction C via the second circumferential groove 14 at the end portion of the rotor shaft 70 on the second axial side L2.

[0042] In this embodiment, the connecting shaft 72 has an oil hole (hereinafter, sometimes referred to as a "communicating oil hole" to distinguish it from the oil hole 60 formed in the rotor shaft 70) that communicates between the internal space of the connecting shaft 72 and the outer circumferential surface of the connecting shaft 72. The communicating oil hole is formed so as to penetrate the connecting shaft 72 in the radial direction R. Here, the connecting shaft 72 has communicating oil holes at two locations in the axial direction L. Here, the communicating oil holes provided at the two locations in the axial direction L are referred to as a fifth oil hole 65 and a sixth oil hole 66, in that order from the first axial side L1. The fifth oil hole 65 and the sixth oil hole 66 are arranged at different positions from each other in the circumferential direction C.

[0043] In this embodiment, a second groove 20 extending in the axial direction L is formed on the inner circumferential surface of the connecting shaft 72. The second groove 20 is formed to extend at least in the axial direction L. As shown in FIG. 3 , in this embodiment, the second groove 20 is formed to extend parallel to the axial direction L. The second groove 20 is formed to be recessed radially outward R2 from the inner circumferential surface of the connecting shaft 72. Therefore, as shown in FIGS. 4 and 5 , the second cylindrical space S2 formed between the outer circumferential surface of the shaft member 71 and the inner circumferential surface of the connecting shaft 72 expands radially outward R2 at the location where the second groove 20 is formed. Note that in FIG. 5 , a second connecting groove 21 and a second non-connecting groove 22, which will be described later, correspond to the second groove 20. The size of the gap in the radial direction R between the outer peripheral surface of the shaft member 71 and a reference inner peripheral surface, which is a portion of the inner peripheral surface of the connecting shaft 72 where the second grooves 20 are not formed, is set to be smaller than, for example, the depth of the deepest part of the second grooves 20 (the depth from the reference inner peripheral surface). The cross-sectional shape of the second grooves 20 can be various shapes such as a U-shape, a semicircular shape, a V-shape, a rectangular shape, etc.

[0044] In this embodiment, a plurality of second grooves 20 are formed on the inner circumferential surface of the connecting shaft 72. The plurality of second grooves 20 includes a second connecting groove 21 connected to the fifth oil hole 65, a second connecting groove 21 connected to the sixth oil hole 66, and a second non-connecting groove 22 that is not connected to a communicating oil hole and extends in the axial direction L to the end of the connecting shaft 72 on the second axial side L2. Although not shown in the figures, the plurality of second grooves 20 are arranged, for example, at equal intervals in the circumferential direction C.

[0045] In the present embodiment, the second connection groove 21 is formed to extend in the axial direction L from the end of the connecting shaft 72 on the first axial side L1 to the position where the connecting oil hole to which it is connected is formed. Also, in the present embodiment, the second non-connection groove 22 is formed to extend in the axial direction L from the end of the connecting shaft 72 on the first axial side L1 to the end of the connecting shaft 72 on the second axial side L2. In this way, the second groove 20 (specifically, the second connection groove 21 and the second non-connection groove 22) is formed to extend from the end of the connecting shaft 72 on the first axial side L1 toward the second axial side L2. The first non-connection groove 12 and the second groove 20 communicate with each other via the second circumferential groove 14 formed in the end of the second axial side L2 on the inner circumferential surface of the rotor shaft 70.

[0046] As shown in FIG. 2, the vehicle drive device 100 includes an oil supply unit 6 that supplies oil to the rotor shaft 70. In this embodiment, the oil supply unit 6 supplies oil supplied from an oil pump OP to the rotor shaft 70. The oil pump OP is an electric pump driven by an electric motor (a dedicated electric motor separate from the rotating electric machine 5). The oil pump OP may also be a mechanical pump driven by power transmitted through a power transmission path between the rotating electric machine 5 and the output member 30 (in other words, the driving force of the rotating electric machine 5).

[0047] The oil supply unit 6 is configured to supply oil to an internal space S of the rotor shaft 70 on a first axial side L1 with respect to the rotor 50 (specifically, the rotor core 50a). In the present embodiment, a shaft member 71 is disposed in the internal space S of the rotor shaft 70. Therefore, the oil supply unit 6 is configured to supply oil between the inner circumferential surface of the rotor shaft 70 and the outer circumferential surface of the shaft member 71 in the radial direction R (in other words, to the first cylindrical space S1). In the present embodiment, the oil supply unit 6 includes an oil passage 7 formed in the case 9 (specifically, the shaft end wall). The oil passage 7 supplies oil supplied from the oil pump OP to the internal space S of the rotor shaft 70 (specifically, between the inner circumferential surface of the rotor shaft 70 and the outer circumferential surface of the shaft member 71 in the radial direction R). In the example shown in FIG. 2, the oil passage 7 is formed to open to the inner circumferential surface of a through-hole formed in the case 9. A cylindrical member 8 is disposed on the inner peripheral surface of this, and oil in the oil passage 7 is supplied to the internal space S of the rotor shaft 70 through a hole formed in the cylindrical member 8.

[0048] 2, the opening of the oil passage 7 in the inner peripheral surface of the case 9 is disposed on the first axial side L1 relative to the end of the rotor shaft 70 on the first axial side L1. Here, this opening is disposed between the first bearing B1 and the second bearing B2 in the axial direction L. The oil in the oil passage 7 is supplied to the internal space S of the rotor shaft 70 from the opening on the first axial side L1 of the rotor shaft 70. Alternatively, for example, a through-hole communicating the internal space S with the outer peripheral surface of the rotor shaft 70 may be formed in a portion of the rotor shaft 70 disposed on the first axial side L1 relative to the rotor core 50a, and the oil in the oil passage 7 may be supplied to the internal space S of the rotor shaft 70 from this through-hole.

[0049] 2, the oil supplied from the oil supply unit 6 to the first cylindrical space S1 flows through the first cylindrical space S1 toward the second axial side L2. At this time, the oil present in the first cylindrical space S1 is subjected to a force toward the inner circumferential surface of the rotor shaft 70 due to centrifugal force generated by the rotation of the rotor shaft 70, and the first connecting groove 11 connected to the first oil hole 61, the second oil hole 62, the third oil hole 63, and the fourth oil hole 64 are formed on this inner circumferential surface. Therefore, the oil supplied from the oil supply unit 6 to the first cylindrical space S1 can be divided and circulated through the multiple first connecting grooves 11 connected to the first oil hole 61, the second oil hole 62, the third oil hole 63, and the fourth oil hole 64, respectively. This allows oil to be appropriately supplied to each of the first oil hole 61, the second oil hole 62, the third oil hole 63, and the fourth oil hole 64.

[0050] In this embodiment, oil supplied to the first oil hole 61 is discharged from the first oil hole 61 and supplied to the coil end portion 51b (see FIG. 1) on the first axial side L1, and oil supplied to the second oil hole 62 is discharged from the second oil hole 62 and supplied to the coil end portion 51b (see FIG. 1) on the second axial side L2. Oil supplied to the third oil hole 63 is discharged from the third oil hole 63 and supplied to the third bearing B3, and oil supplied to the fourth oil hole 64 is discharged from the fourth oil hole 64 and supplied to the fourth bearing B4 and the bearings supporting the pinion gears (PG1, PG2), which are parts of the planetary gear mechanism 3 that require lubrication. In this way, in this embodiment, at least a portion of the multiple oil holes 60 (here, the fourth oil hole 64) communicates with parts of the gear mechanism 2 that require lubrication (here, the planetary gear mechanism 3). As will be described later, in this embodiment, the end of the first non-connection groove 12 on the second axial side L2 also communicates with parts of the gear mechanism 2 that require lubrication.

[0051] In the present embodiment, the oil supplied from the oil supply unit 6 to the first cylindrical space S1 can also flow through the first non-connection groove 12. Therefore, a portion of the oil supplied from the oil supply unit 6 to the first cylindrical space S1 can be made to flow appropriately to the end of the rotor shaft 70 on the second axial side L2. Then, in the present embodiment, the oil that has flowed to the end of the rotor shaft 70 on the second axial side L2 is supplied to the internal space (here, the second cylindrical space S2) of the connecting shaft 72. In the present embodiment, the second circumferential groove 14 described above is formed at the end of the second axial side L2 on the inner circumferential surface of the rotor shaft 70, which facilitates smooth flow of oil from the first cylindrical space S1 to the second cylindrical space S2. The second grooves 20 extending further from the second circumferential groove 14 toward the second axial side L2 do not necessarily have to be provided in the same straight line as the first grooves 10. For example, the second grooves 20 may be formed to extend from the second circumferential groove 14 toward the second axial side L2 at a position in the circumferential direction C different from that of the first grooves 10. The number of second grooves 20 may be set to a number different from the number of first grooves 10. In other words, the second grooves 20 may be formed to newly branch off from the second circumferential groove 14 and extend toward the second axial side L2.

[0052] The oil supplied to the second cylindrical space S2 flows through the second cylindrical space S2 toward the second axial side L2. At this time, a centrifugal force generated by the rotation of the connecting shaft 72 acts on the oil present in the second cylindrical space S2, causing a force toward the inner circumferential surface of the connecting shaft 72, and the second connection groove 21 connected to the fifth oil hole 65, the second connection groove 21 connected to the sixth oil hole 66, and the second non-connection groove 22 are formed on this inner circumferential surface. Therefore, the oil supplied to the second cylindrical space S2 can be divided and circulated through the second connection groove 21 connected to the fifth oil hole 65, the second connection groove 21 connected to the sixth oil hole 66, and the second non-connection groove 22. This allows the oil to be appropriately supplied to each of the fifth oil hole 65 and the sixth oil hole 66, and allows a portion of the oil supplied to the second cylindrical space S2 to appropriately flow to the end of the connecting shaft 72 on the second axial side L2.

[0053] In the present embodiment, oil supplied to the fifth oil hole 65 is discharged from the fifth oil hole 65 and supplied to the sun gear SG, and oil supplied to the sixth oil hole 66 is discharged from the sixth oil hole 66 and supplied to the fifth bearing B5. Furthermore, oil that has flowed to the end of the connecting shaft 72 on the second axial side L2 is supplied to the differential gear mechanism 4. In this manner, in the present embodiment, at least some of the multiple communicating oil holes (here, the fifth oil hole 65 and the sixth oil hole 66) communicate with parts of the gear mechanism 2 (here, the planetary gear mechanism 3) that require lubrication. Furthermore, the end of the second non-connection groove 22 on the second axial side L2 communicates with parts of the gear mechanism 2 (here, the differential gear mechanism 4) that require lubrication. That is, in this embodiment, the end of the first non-connecting groove 12 formed on the inner surface of the rotor shaft 70 on the second axial side L2 is connected to the parts of the gear mechanism 2 that require lubrication via the second groove 20 formed on the inner surface of the connecting shaft 72.

[0054] In this vehicle drive device 100, oil supplied to the internal space S of the rotor shaft 70 by the oil supply unit 6 can be appropriately supplied to each of the locations requiring oil, as described above. Therefore, it is not necessary to form an oil passage in the shaft member 71 for supplying oil to the oil hole 60 formed in the rotor shaft 70 (and in this embodiment, a communicating oil hole formed in the connecting shaft 72), making it easy to reduce the diameter of the shaft member 71 while ensuring the strength of the shaft member 71. By reducing the diameter of the shaft member 71, it is possible to reduce the diameter of each component arranged on the radially outer side R2 of the shaft member 71, and the overall size of the vehicle drive device 100 can be reduced.

[0055] From the viewpoint of reducing oil drag resistance due to the difference in rotational speed between the rotor shaft 70 and the shaft member 71, it is desirable that the oil supply flow rate from the oil supply unit 6 to the internal space S of the rotor shaft 70 be such that the oil in the first cylindrical space S1 flows mainly through the first groove 10 and an air layer is formed between the inner circumferential surface of the rotor shaft 70 and the outer circumferential surface of the shaft member 71. In this embodiment, it is further desirable that the oil supply flow rate be such that the oil in the second cylindrical space S2 flows mainly through the second groove 20 and an air layer is formed between the inner circumferential surface of the connecting shaft 72 and the outer circumferential surface of the shaft member 71. The oil supply flow rate at which the air layer is formed may vary depending on the vehicle conditions, such as the rotational speed of the rotor 50. Therefore, for example, a control device that controls the oil pump OP may be configured to control the oil supply flow rate from the oil supply unit 6 to the internal space S of the rotor shaft 70 depending on the vehicle conditions, so that the air layer is formed.

[0056] Other Embodiments (1) In the above embodiment, a configuration has been described as an example in which the plurality of second grooves 20 include both the second connecting groove 21 and the second non-connecting groove 22. However, the present disclosure is not limited to such a configuration, and the plurality of second grooves 20 may not include either the second connecting groove 21 or the second non-connecting groove 22. Furthermore, a configuration in which only one second groove 20 is formed on the inner circumferential surface of the connecting shaft 72, or a configuration in which no second groove 20 is formed on the inner circumferential surface of the connecting shaft 72 may also be used.

[0057] (2) In the above embodiment, a configuration has been described as an example in which the plurality of first grooves 10 includes the first non-connecting groove 12. However, the present disclosure is not limited to such a configuration, and the plurality of first grooves 10 may also be configured not to include the first non-connecting groove 12. For example, the plurality of first grooves 10 may be configured to include only the first connecting groove 11.

[0058] (3) In the above embodiment, the first connection groove 11 has been described as having a configuration in which the depth of the connection portion 11a connected to the oil hole 60 is set to be the same as the depth of the other portions. However, the present disclosure is not limited to such a configuration, and at least some of the multiple first connection grooves 11 may have a depth of the connection portion 11a connected to the oil hole 60 that is greater than the depth of the other portions. The first connection groove 11 shown in FIG. 8 is the first connection groove 11 connected to the first oil hole 61, and this first connection groove 11 has a depth of the connection portion 11a that is greater than the depth of the other portions (specifically, the portion closer to the first axial side L1 than the connection portion 11a). Similarly, with respect to the second connection groove 21, the depth of the connection portion connected to the communicating oil hole (in the above embodiment, the fifth oil hole 65 or the sixth oil hole 66) may be set to be the same as or greater than the depth of the other portions.

[0059] (4) In the above embodiment, a configuration has been described as an example in which each of the multiple first grooves 10 is formed to extend parallel to the axial direction L. However, the present disclosure is not limited to such a configuration, and at least some of the multiple first grooves 10 may be formed to extend in a direction inclined with respect to the axial direction L. For example, each of the multiple first grooves 10 may be formed in a spiral shape along the inner circumferential surface of the rotor shaft 70. In this case, the spiral direction is set, for example, to a direction that promotes the flow of oil to the second axial side L2 when the rotor shaft 70 is rotating in a direction that moves the vehicle forward. Similarly, each of the multiple second grooves 20 may be formed in a spiral shape along the inner circumferential surface of the connecting shaft 72.

[0060] (5) In the above embodiment, the power transmission mechanism 1 includes a connecting shaft 72 connected to the rotor shaft 70 so as to extend from the rotor shaft 70 toward the second axial side L2, and a gear (sun gear SG in the above embodiment) that rotates integrally with the rotor shaft 70 is provided on the connecting shaft 72. However, the present disclosure is not limited to such a configuration, and the power transmission mechanism 1 may also be configured without the connecting shaft 72. In this case, for example, a gear may be formed on a cylindrical member connected to the outer circumferential surface of the rotor shaft 70, or a gear may be formed on the outer circumferential surface of the rotor shaft 70.

[0061] (6) In the above embodiment, the shaft member 71, which is arranged to extend in the axial direction L in the internal space S of the rotor shaft 70, is a member for connecting the first output member 31 and the first drive shaft DS1. However, the present disclosure is not limited to such a configuration. For example, when the first output member 31 and the first drive shaft DS1 are directly connected, the first output member 31 may be the shaft member 71. Furthermore, the shaft member 71 may not be a member connected to the first drive shaft DS1, but may be a member provided in the vehicle drive device 100 for another purpose. Furthermore, a configuration in which the shaft member 71 is not arranged in the internal space S of the rotor shaft 70 is also possible.

[0062] (7) Note that the configurations disclosed in the above-described embodiments can be applied in combination with configurations disclosed in other embodiments (including combinations of embodiments described as other embodiments) as long as no contradictions arise. Regarding other configurations, the embodiments disclosed in this specification are merely examples in all respects. Therefore, various modifications can be made as appropriate within the scope of the present disclosure.

[0063] [Summary of this embodiment] The above-described embodiment of the vehicle drive device will be summarized below.

[0064] The vehicle drive device (100) includes an output member (30) drivingly connected to a wheel (W), a rotating electric machine (5) including a rotor (50), a cylindrical rotor shaft (70) that rotates integrally with the rotor (50), a power transmission mechanism (1) that transmits power between the rotor shaft (70) and the output member (30), and an oil supply unit (6) that supplies oil to the rotor shaft (70), wherein a direction along a rotation axis (A) of the rotor (50) is defined as an axial direction (L), one side of the axial direction (L) is defined as an axial first side (L1), and the other side of the axial direction (L) is defined as an axial second side (L2), The oil supply section (6) is configured to supply oil to the internal space (S) of the rotor shaft (70) on the first axial side (L1) of the rotor (50), and the rotor shaft (70) has oil holes (60) that connect the internal space (S) and the outer peripheral surface of the rotor shaft (70) at multiple locations in the axial direction (L) on the second axial side (L2) of the oil supply section (6), and a plurality of grooves (10) extending in the axial direction (L) are formed on the inner peripheral surface of the rotor shaft (70), and the multiple grooves (10) include a plurality of connecting grooves (11) that are connected to different oil holes (60) from each other.

[0065] According to this configuration, oil supplied by the oil supply unit (6) to the internal space (S) of the rotor shaft (70) can be supplied to each of the oil holes (60) provided at multiple locations in the axial direction (L) on the second axial side (L2) of the oil supply unit (6) while flowing toward the second axial side (L2). At this time, a centrifugal force caused by the rotation of the rotor shaft (70) acts on the oil present in the internal space (S) toward the inner circumferential surface of the rotor shaft (70), and multiple connecting grooves (11) connected to different oil holes (60) are formed on this inner circumferential surface. Therefore, the oil supplied by the oil supply unit (6) to the internal space (S) of the rotor shaft (70) can be divided and circulated through the multiple connecting grooves (11) connected to different oil holes (60). Therefore, it is less likely that the amount of oil supplied to the oil holes (60) on the first axial side (L1), which is the side closer to the oil supply section (6), will be too large, resulting in an insufficient amount of oil being supplied to the oil holes (60) on the second axial side (L2), which is the side farther from the oil supply section (6), and oil can be appropriately supplied to each of the oil holes (60) formed at multiple locations in the axial direction (L).

[0066] As described above, according to this configuration, even if an oil passage for supplying oil to the oil holes (60) formed in the rotor shaft (70) is not formed in the shaft member (71) arranged in the internal space (S) of the rotor shaft (70), or even if the shaft member (71) is not arranged in the internal space (S) of the rotor shaft (70), it is possible to appropriately supply oil to each of the oil holes (60) formed at multiple locations in the axial direction (L) of the rotor shaft (70).

[0067] Here, the direction perpendicular to the rotation axis (A) is defined as a radial direction (R), and it is preferable that the power transmission mechanism (1) includes a shaft member (71) arranged to extend in the axial direction (L) in the internal space (S), and the oil supply unit (6) is configured to supply oil between the inner peripheral surface of the rotor shaft (70) and the outer peripheral surface of the shaft member (71) in the radial direction (R).

[0068] According to this configuration, the shaft member (71) can restrict oil from flowing in a region of the internal space (S) of the rotor shaft (70) that is far away radially inward (R1) from the inner circumferential surface of the rotor shaft (70) where the multiple connecting grooves (11) are formed. Therefore, regardless of the magnitude of the centrifugal force caused by the rotation of the rotor shaft (70), it is easy to ensure that the oil supplied from the oil supply portion (6) to the internal space (S) of the rotor shaft (70) flows appropriately toward the oil holes (60), and it is easy to appropriately supply oil to each of the multiple oil holes (60).

[0069] It is also preferable that the plurality of grooves (10) include a non-connected groove (12) that extends in the axial direction (L) to the end of the second axial side (L2) of the rotor shaft (70) without being connected to the oil hole (60).

[0070] This configuration makes it easy to cause a portion of the oil supplied by the oil supply part (6) to the internal space (S) of the rotor shaft (70) to flow to the end of the rotor shaft (70) on the second axial side (L2). Thus, oil can be reliably supplied to the second axial side (L2) beyond the end of the rotor shaft (70) on the second axial side (L2).

[0071] Preferably, at least some of the plurality of connecting grooves (11) have a connecting portion (11a) connected to the oil hole (60) that has a depth greater than the depth of the other portions.

[0072] According to this configuration, for at least some of the plurality of connecting grooves (11), it is possible to increase the proportion of oil that has flowed through the connecting grooves (11) to the connecting portions (11a) with the oil holes (60) and is supplied to the oil holes (60). Therefore, it is easy to supply a large amount of oil to the oil holes (60).

[0073] Preferably, each of the plurality of recessed grooves (10) is formed in a spiral shape along the inner peripheral surface of the rotor shaft (70).

[0074] According to this configuration, the rotation of the rotor shaft (70) can be utilized to promote the flow of oil in the groove (10) in the axial direction (L).

[0075] Preferably, the power transmission mechanism (1) includes a gear mechanism (2) arranged on the second axial side (L2) of the rotor (50), and at least some of the plurality of oil holes (60) communicate with locations of the gear mechanism (2) that require lubrication.

[0076] According to this configuration, oil supplied from the oil supply unit (6) can also be supplied to the gear mechanism (2) disposed on the second axial side (L2) opposite to the side on which the oil supply unit (6) is disposed with respect to the rotor (50). Therefore, oil can be easily supplied appropriately to the parts of the gear mechanism (2) that require lubrication.

[0077] Preferably, the direction going around the rotation axis (A) is defined as a circumferential direction (C), and the plurality of recessed grooves (10) are arranged at equal intervals in the circumferential direction (C).

[0078] According to this configuration, the variation in the spacing between the recessed grooves (10) in the circumferential direction (C) can be reduced, which makes it easier to ensure the strength of the rotor shaft (70).

[0079] It is sufficient for the vehicle drive device according to the present disclosure to achieve at least one of the above-described effects. [Explanation of symbols]

[0080] 1: power transmission mechanism, 5: rotating electric machine, 6: oil supply portion, 10: first groove (groove), 11: first connecting groove (connecting groove), 11a: connecting portion, 12: first non-connecting groove (non-connecting groove), 30: output member, 50: rotor, 60: oil hole, 70: rotor shaft, 71: shaft member, 100: vehicle drive device, A: rotation axis, L: axial direction, L1: first axial side, L2: second axial side, R: radial direction, S: internal space, W: wheel

Claims

1. A vehicle drive device including: an output member drivingly connected to a wheel; a rotating electric machine including a rotor; a cylindrical rotor shaft rotating integrally with the rotor; a power transmission mechanism for transmitting power between the rotor shaft and the output member; and an oil supply unit for supplying oil to the rotor shaft, A direction along the rotation axis of the rotor is defined as an axial direction, one side of the axial direction is defined as an axial first side, and the other side of the axial direction is defined as an axial second side, the oil supply unit is configured to supply oil to an internal space of the rotor shaft on the first axial side of the rotor, the rotor shaft includes oil holes communicating the internal space with an outer peripheral surface of the rotor shaft at a plurality of locations in the axial direction on the second axial side relative to the oil supply portion, a plurality of grooves extending in the axial direction are formed on the inner peripheral surface of the rotor shaft; The plurality of grooves includes a plurality of connecting grooves connected to different oil holes.

2. The direction perpendicular to the rotation axis is defined as a radial direction, the power transmission mechanism includes a shaft member disposed in the internal space so as to extend in the axial direction, The vehicle drive device according to claim 1 , wherein the oil supply unit is configured to supply oil to a radial gap between an inner peripheral surface of the rotor shaft and an outer peripheral surface of the shaft member.

3. 3. The vehicle drive device according to claim 1, wherein the plurality of grooves include a non-connected groove that extends in the axial direction to the end of the rotor shaft on the second axial side without being connected to the oil hole.

4. 3. The vehicle drive device according to claim 1, wherein at least some of the plurality of connecting grooves have a connecting portion connected to the oil hole that is set to have a depth greater than a depth of other portions.

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