Rotating electric machine and vehicle drive device

Abstract

To provide a rotary electric machine and vehicle drive device capable of stably supplying oil to a spline fitting part related to a rotor shaft.SOLUTION: A rotary electric machine includes: a stator; a rotor with a hollow rotor shaft 314; and an oil formation member forming an oil path for supplying oil to a hollow inside of the rotor shaft. The rotor shaft has an inner-peripheral surface, which includes a weir section projecting toward inward in the radial direction over the whole periphery in the peripheral direction and a female spline 71 meshing with a male spline 72 of a rotating shaft member 31 for rotational torque transmission. The oil path supplies oil between the weir section and the spline in the axial direction, and the inside diameter r2 of the weir section is smaller than a large diameter r1 of the female spline of the rotor shaft.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to a rotating electric machine and a vehicle drive device. [Background technology]

[0002] A technology is known in which a spline for power transmission (female spline) is formed on the inner surface of a hollow rotor shaft, a spline for power transmission (male spline) is formed on the outer surface of an input shaft, and the two are spline-fitted together, thereby enabling the rotational torque of a rotating electric machine to be transmitted to wheels via the input shaft. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-129608 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the above-described conventional technology, it is difficult to stably supply oil to the spline-fitted portion between the input shaft and the rotor shaft.

[0005] Therefore, in one aspect, an object of the present disclosure is to stably supply oil to a spline fitting portion of a rotor shaft. [Means for solving the problem]

[0006] In one aspect, a rotor includes a stator; a rotor having a hollow rotor shaft; an oil passage forming member that forms an oil passage for supplying oil to a hollow interior of the rotor shaft, the rotor shaft has, on an inner peripheral surface thereof, a dam portion that protrudes radially inward over the entire circumferential direction, and a female spline that meshes with a male spline of a rotating shaft member for transmitting rotational torque, the oil passage supplies oil between the dam portion and the spline in an axial direction, A rotating electric machine is provided, in which an inner diameter of the dam portion is smaller than a large diameter of the female spline of the rotor shaft. Effect of the Invention

[0007] According to one aspect, the present disclosure makes it possible to stably supply oil to a spline fitting portion of a rotor shaft. [Brief description of the drawings]

[0008] [Figure 1] 1 is a skeleton diagram of a vehicle drive system including a rotating electric machine. [Diagram 2] 1 is a cross-sectional view showing a schematic view of a main part of a rotating electric machine; [Diagram 3] FIG. 3 is an enlarged view of part Q1 in FIG. [Figure 4] FIG. 3 is an enlarged view of part Q2 in FIG. [Diagram 5] FIG. 3 is an enlarged view of part Q3 in FIG. 2. [Figure 6] FIG. 4 is a cross-sectional view of a portion of a spline fitting portion. [Figure 7] FIG. 11 is a cross-sectional view showing a fitting portion according to a first modified example. [Figure 7A] FIG. 8 is an enlarged view of part Q4 in FIG. [Figure 8] FIG. 11 is a cross-sectional view showing a fitting portion according to a second modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] In the following, first, a vehicle drive system 100 to which the rotating electric machine 1 according to this embodiment can be suitably applied will be described, and then the rotating electric machine 1 according to this embodiment will be described in detail.

[0010] [Entire drive system] Fig. 1 is a skeleton diagram of a vehicle drive system 100 including a rotating electric machine 1. In Fig. 1, an X direction and an X1 side and an X2 side along the X direction are defined. The X direction is parallel to the direction of a first axis A1 (hereinafter also referred to as the "axial direction").

[0011] 1, a vehicle drive system 100 includes a rotating electric machine 1 that serves as a drive source for wheels W, and a power transmission mechanism 7 provided in a power transmission path that connects the rotating electric machine 1 and the wheels W. The power transmission mechanism 7 includes an input member 3, a counter gear mechanism 4, a differential gear mechanism 5, and left and right output members 6A, 6B.

[0012] The input member 3 has an input shaft 31 and an input gear 32. The input shaft 31 is a rotating member that rotates around the first axis A1. The input gear 32 is a gear that transmits rotational torque (driving force) from the rotating electric machine 1 to the counter gear mechanism 4. The input gear 32 is provided on the input shaft 31 of the input member 3 so as to rotate integrally with the input shaft 31 of the input member 3.

[0013] The counter gear mechanism 4 is disposed in the power transmission path between the input member 3 and the differential gear mechanism 5. The counter gear mechanism 4 has a counter shaft 41, a first counter gear 42, and a second counter gear 43.

[0014] The counter shaft 41 is a rotating member that rotates around the second shaft A2. The second shaft A2 extends parallel to the first shaft A1. The first counter gear 42 is an input element of the counter gear mechanism 4. The first counter gear 42 meshes with the input gear 32 of the input member 3. The first counter gear 42 is connected to the counter shaft 41 so as to rotate integrally therewith.

[0015] The second counter gear 43 is an output element of the counter gear mechanism 4. In the present embodiment, for example, the second counter gear 43 is formed to have a smaller diameter than the first counter gear 42. The second counter gear 43 is provided on the counter shaft 41 so as to rotate integrally with the counter shaft 41.

[0016] The differential gear mechanism 5 is disposed on a third axis A3 serving as the rotation axis thereof. The third axis A3 extends parallel to the first axis A1. The differential gear mechanism 5 distributes the driving force transmitted from the rotating electric machine 1 to left and right output members 6A and 6B. The differential gear mechanism 5 includes a differential input gear 51 that meshes with the second counter gear 43 of the counter gear mechanism 4. The differential gear mechanism 5 also includes a differential case 52 that houses a pinion shaft, a pinion gear, left and right side gears, etc. The left and right side gears are connected to the left and right output members 6A and 6B so as to rotate integrally therewith, respectively.

[0017] The left and right output members 6A, 6B are drivingly connected to the left and right wheels W, respectively. The left and right output members 6A, 6B transmit the driving force distributed by the differential gear mechanism 5 to the wheels W. Note that the left and right output members 6A, 6B may be constituted by two or more members.

[0018] In this way, the rotating electric machine 1 drives the wheels W via the power transmission mechanism 7. However, in other embodiments, the vehicle drive system 100 may be configured not to include the power transmission mechanism 7. In other embodiments, other power transmission mechanisms such as a planetary gear mechanism may be used.

[0019] [Details of rotating electric machines] FIG. 2 is a cross-sectional view that shows a schematic view of a main part of the rotating electric machine 1. FIG. 3 is an enlarged view of a Q1 part in FIG. 2. FIG. 4 is an enlarged view of a Q2 part in FIG. 2. FIG. 5 is an enlarged view of a Q3 part in FIG. 2. FIG. 6 is a cross-sectional view of a part of the spline fitting part 70, taken along a line A4-A4 in FIG. 5. FIG. 2 defines a Z direction and a Z1 side and a Z2 side along the Z direction. The Z direction is a direction perpendicular to the axial direction and corresponds to the up-down direction. Here, the Z1 side is the upper side, and the Z2 side is the lower side. However, the Z direction does not need to be strictly parallel to the direction of gravity, and may be a direction that is slightly inclined with respect to the direction of gravity. In the following description, terms such as a radial direction and a circumferential direction are based on the first axis A1, and unless otherwise specified, an inner diameter is an inner diameter based on the first axis A1.

[0020] The rotating electric machine 1 has a rotor 310 and a stator 320 in a case 2 .

[0021] The case 2 may be made of aluminum, for example. The case 2 may be formed by casting or the like. The case 2 includes a motor case 250 and a cover member 252. The case 2 houses the rotating electric machine 1. In the case of the vehicle drive system 100 shown in FIG. 1, the case 2 may further house a power transmission mechanism 7, as shown typically in FIG. 1.

[0022] The motor case 250 forms a motor accommodation chamber SP1 that accommodates the rotating electric machine 1. The motor accommodation chamber SP1 may be an oil-tight space that contains oil for cooling and / or lubricating the rotating electric machine 1 (and / or the power transmission mechanism 7). The motor case 250 has a peripheral wall that surrounds the radial outside of the rotating electric machine 1. The motor case 250 may be realized by combining a plurality of members. Furthermore, the motor case 250 may be integrated with another case member 254 that forms a gear accommodation chamber SP2 that accommodates the power transmission mechanism 7 on the X-direction X1 side.

[0023] The cover member 252 is coupled to the X2 side of the motor case 250 in the X direction. The cover member 252 is in the form of a cover that covers the X2 side of the motor housing chamber SP1 in the X direction. In this case, the cover member 252 may cover the motor housing chamber SP1 in such a manner that the opening on the X2 side in the X direction of the motor case 250 is completely or almost completely blocked. Note that a portion of the motor housing chamber SP1 may be formed by the cover member 252.

[0024] The cover member 252 is provided with a bearing 240 that rotatably supports the rotor 310. That is, the cover member 252 has a bearing support portion 2524 that supports the bearing 240.

[0025] 2, bearing 240 is provided on the radially outer side of the end portion on the X2 side of rotor shaft 314. Specifically, the radially outer side of the outer race of bearing 240 is supported by cover member 252, and the radially inner side of the inner race is supported by the outer circumferential surface of rotor shaft 314. Note that in a modified example, the opposite may be true, where the radially inner side of the inner race of bearing 240 is supported by cover member 252, and the radially outer side of the outer race is supported by the inner circumferential surface of rotor shaft 314.

[0026] 2, the cover member 252 includes a circular bottom 2521 centered on the first axis A1, and a peripheral wall 2522 protruding from the outer periphery of the bottom 2521 toward the X1 side in the X-direction, and an end face of the peripheral wall 2522 on the X1 side in the X-direction is joined to the motor case 250. On the X1 side in the X-direction of the bottom 2521 having a thickness in the X-direction, a cylindrical bearing support 2524 protruding toward the X1 side in the X-direction is formed in a central portion (a portion centered on the first axis A1) as viewed in the axial direction. The bearing support 2524 is formed concentrically with the first axis A1 as the center.

[0027] 2, an axial protrusion 2525 is formed on the radial inside of the cylindrical bearing support portion 2524 at a central portion (portion centered on the first axis A1) on the X1 side of the bottom portion 2521 in the X direction when viewed in the axial direction. The axial protrusion 2525 is formed at the central portion (portion centered on the first axis A1) on the X1 side of the bottom portion 2521 in the X direction so as to protrude toward the X1 side in the X direction.

[0028] In the cover member 252, a cover oil passage 80, a first oil passage 81, and a second oil passage 82 are formed.

[0029] The cover oil passage 80 is formed in the bottom 2521 of the cover member 252. The cover oil passage 80 communicates with the discharge side of an oil pump (not shown). In this case, oil discharged from the oil pump is supplied to the cover oil passage 80. The oil pump may be a mechanical type, or an electric type driven by an electric motor.

[0030] The first oil passage 81 is formed in the axial protruding portion 2525 of the cover member 252, and extends linearly in the axial direction. The end of the first oil passage 81 on the X-direction X2 side communicates with the cover oil passage 80, and the end on the X-direction X1 side is open. The first oil passage 81 on the X-direction X1 side extends to the hollow interior 314A of the rotor shaft 314. Note that, as shown in FIG. 3, the center axis I1 of the first oil passage 81 may be offset upward with respect to the first axis A1 so that the distance L1 (see FIG. 2) to the landing position P1 of the oil discharged from the first oil passage 81 can be made relatively long.

[0031] The second oil passage 82 is formed in the axial protruding portion 2525 of the cover member 252, and communicates with the cover oil passage 80 via the first oil passage 81. The second oil passage 82 branches off from the first oil passage 81, and extends obliquely downward toward the X1 side in the X-direction.

[0032] The rotor 310 includes a rotor core 312 and a rotor shaft 314 .

[0033] Rotor core 312 may be made of, for example, laminated steel plates of a magnetic material having a circular ring shape. Permanent magnets (not shown) may be embedded inside rotor core 312. Alternatively, permanent magnets (not shown) may be attached to the outer circumferential surface of rotor core 312. The arrangement of permanent magnets (not shown) is optional. Rotor core 312 is fixed to the outer circumferential surface of rotor shaft 314 and rotates integrally with rotor shaft 314.

[0034] The rotor shaft 314 defines a first axis A1 which is a rotation axis of the rotating electric machine 1. The rotor shaft 314 is rotatably supported by a cover member 252 of the case 2 via a bearing 240 on the X2 side of a portion to which the rotor core 312 is fixed. The rotor shaft 314 is rotatably supported by the case 2 via a bearing 241 on the other axial end side (X1 side) of the rotating electric machine 1. In this manner, the rotor shaft 314 may be rotatably supported by the case 2 at both axial ends.

[0035] As shown in Fig. 5, the rotor shaft 314 is connected to the input shaft 31 on the X1 side in the X direction so as to be capable of transmitting power. In this embodiment, as an example, a spline (hereinafter referred to as a "female spline 71") is formed on the inner peripheral surface of the rotor shaft 314, and is spline-fitted (loose fit) in a manner that it meshes with a spline (hereinafter referred to as a "male spline 72") formed on the outer peripheral surface of the input shaft 31. For example, in this embodiment, as shown in Fig. 6, the meshing of the female spline 71 and the male spline 72 may be realized by a large diameter fitting in which the tooth tip (large diameter surface 721) of the male spline 72 is abutted against the tooth base (large diameter surface 711) of the female spline 71 in the radial direction. Hereinafter, the entire portion where the rotor shaft 314 and the input shaft 31 are connected by spline fitting in this manner is referred to as a "spline fitting portion 70".

[0036] In this embodiment, the major diameter r1 of the female spline 71 (= the inner diameter of the large diameter surface 711) is set to be slightly larger than the inner diameter r2 (see FIG. 3) of the dam portion 89 described later, as shown in Figures 5 and 6. The technical significance of this relationship between the inner diameters will be described later. Note that the detailed shape of the female spline 71 (as well as the male spline 72) is arbitrary, so long as the major diameter r1 of the female spline 71 is larger than the inner diameter r2 of the dam portion 89 described later.

[0037] In this embodiment, since the large diameter is matched as described above, the large diameter r1 of the female spline 71 is substantially the same as the large diameter r1' (= the inner diameter of the large diameter surface 721) of the male spline 72. Therefore, in the following description, the "large diameter r1 of the female spline 71" can also be read as the "large diameter r1' of the male spline 72."

[0038] The rotor shaft 314 is, for example, in the form of a hollow tube, and has a hollow interior 314A. The hollow interior 314A may extend over the entire axial length of the rotor shaft 314. In this embodiment, as an example, the inner circumferential surface of the rotor shaft 314 has a constant inner diameter r0 except for a section where the female spline 71 is formed. However, in other embodiments, the rotor shaft 314 may have a form in which the diameter is reduced at both axial ends or one end, in which case the inner circumferential surface of the rotor shaft 314 may have a constant inner diameter r0 in a portion where the rotor core 312 is fixed, and may have an inner diameter smaller than the inner diameter r0 at both axial ends or one end.

[0039] The hollow interior 314A of the rotor shaft 314 functions as the axial oil passage 83. That is, oil is supplied to the hollow interior 314A via a cover oil passage 80, which will be described later. This allows the rotor shaft 314 to be cooled, thereby cooling the rotor core 312 (and the permanent magnets, if any,) from the radially inner side.

[0040] A dam portion 89 for oil storage is formed in the hollow interior 314A of the rotor shaft 314. That is, the rotor shaft 314 has the dam portion 89 on the inner circumferential surface thereof, which protrudes radially inward over the entire circumference. In the example shown in FIG. 2, the dam portion 89 is formed by an annular plug fitted into the hollow interior 314A of the rotor shaft 314, as an example. However, in a modified example, the dam portion 89 may be realized by the shape of the rotor shaft 314 itself. For example, the rotor shaft 314 may have a shape in which the diameter is reduced at the end on the X2 side in the X direction. In this case, the dam portion 89 may be realized by a step portion on the inner circumferential surface caused by the diameter reduction. In addition, a convex shape corresponding to the dam portion 89 may be realized by utilizing a flow forming process, a hydroforming process, or the like, or may be realized by using a shaft member of two or more pieces.

[0041] Weir portion 89 is preferably disposed on the X2 side in the X-direction relative to third oil passage 831A, which will be described later. This allows oil to be stably supplied to third oil passage 831A by oil (described later with reference to FIG. 4, etc.) stored in weir portion 89. In this case, weir portion 89 may be formed at a position overlapping axial protruding portion 2525 when viewed in the radial direction, as shown in FIG. 2. This allows weir portion 89 to be disposed on the X2 side in the X-direction relative to third oil passage 831A, by utilizing the radial space between axial protruding portion 2525 and the inner circumferential surface of rotor shaft 314.

[0042] In rotor shaft 314, third oil passage 831A and fourth oil passage 831B are formed in the radial direction for discharging oil to coil end portions 322A, 322B of stator 320, respectively.

[0043] The third oil passage 831A has an opening facing the coil end portion 322A in the radial direction, and supplies oil in the axial oil passage 83 toward the coil end portion 322A. Note that, although the third oil passage 831A extends linearly parallel to the radial direction in the example shown in Fig. 2, it may extend linearly in an oblique direction that is slightly inclined with respect to the radial direction.

[0044] The fourth oil passage 831B has an opening facing the coil end portion 322B in the radial direction, and supplies oil in the axial oil passage 83 toward the coil end portion 322B. Note that, although the fourth oil passage 831B extends linearly parallel to the radial direction in the example shown in Fig. 2, it may extend linearly in an oblique direction that is slightly inclined with respect to the radial direction.

[0045] The stator 320 includes a stator core 321 and a stator coil 322 .

[0046] Stator core 321 may be made of, for example, laminated steel plates of a magnetic material having a circular ring shape. Teeth (not shown) are formed radially on the inner periphery of stator core 321 and protrude radially inward.

[0047] The stator coil 322 may be in the form of, for example, a conductor having a rectangular or circular cross section with an insulating coating. The stator coil 322 is wound around teeth (not shown) of the stator core 321. The stator coils 322 may be electrically connected in a Y-connection or a Δ-connection in parallel with one or more coils.

[0048] Stator coil 322 has coil end portions 322A and 322B that protrude axially outward from slots in stator core 321. Coil end portion 322A is located on the X1 side, and coil end portion 322B is located on the X2 side.

[0049] Here, the flow of oil in the oil passage structure of this embodiment will be generally described, and the principle of supplying oil to the spline fitting portion 70 will be described with reference to Figures 3, 4, and 5. In Figures 3 and 4, oil 800 related to an oil sump that may be formed on the inner peripheral surface of the rotor shaft 314 due to the influence of centrifugal force accompanying the rotation of the rotor shaft 314 is typically shown by hatching. Also, in Figure 4, the flow of oil is typically shown by arrows R10 to R32.

[0050] The oil supplied to the cover oil passage 80 (see arrow R10) flows into the first oil passage 81 and flows in the axial direction through the first oil passage 81 (see arrow R12). A part of the oil flowing in the axial direction through the first oil passage 81 is discharged to the landing position P2 on the inner circumferential surface of the rotor shaft 314 (or the surface of the oil 800 accumulated on the inner circumferential surface) through the discharge hole 821 of the second oil passage 82 as described above (see arrow R22). Moreover, the remaining whole of the oil flowing in the axial direction through the first oil passage 81 is discharged to the landing position P1 on the inner circumferential surface of the rotor shaft 314 (or the surface of the oil 800 accumulated on the inner circumferential surface) through the discharge hole 811 of the first oil passage 81 as described above (see arrow R21).

[0051] Here, during operation of the rotating electric machine 1, the oil discharged onto the inner surface of the rotor shaft 314 in this manner flows axially along the inner surface of the rotor shaft 314 while running along the inner surface of the rotor shaft 314 due to the influence of the centrifugal force accompanying the rotation of the rotor shaft 314.

[0052] In this embodiment, since the dam portion 89 is provided on the inner circumferential surface of the rotor shaft 314 on the X2 side in the X direction, the oil flowing toward the X2 side in the X direction is blocked by the dam portion 89. Therefore, in this embodiment, as shown typically in Figures 3 and 4, an oil pool having a thickness t1 that does not extend radially inward beyond the innermost diameter position of the dam portion 89 is likely to be formed on the inner circumferential surface of the rotor shaft 314.

[0053] In this way, part of the oil that accumulates to a thickness t1 on the inner circumferential surface of rotor shaft 314 is discharged to coil end portion 322A via third oil passage 831A (see arrow R31) or to coil end portion 322B via fourth oil passage 831B (see arrow R32) by the centrifugal force accompanying the rotation of rotor shaft 314. This makes it possible to efficiently cool coil end portion 322A and coil end portion 322B.

[0054] According to this embodiment, another portion of the oil that accumulates on the inner circumferential surface of the rotor shaft 314 to a thickness t1 is supplied to the spline fitting portion 70. In Fig. 5, the axial line segment that passes through the innermost diameter position of the dam portion 89 (i.e., the line segment of the inner diameter r2) is indicated by a two-dot chain line 890.

[0055] This allows a stable supply of oil from within the rotor shaft 314 as lubricant to the splined engagement portion 70, which is a power transmission portion, and increases the reliability (eg, wear resistance, etc.) of the splined engagement portion 70.

[0056] Specifically, in this embodiment, the inner circumferential surface of the rotor shaft 314 is not provided with a dam portion such as the dam portion 89 (or a dam portion having an inner diameter smaller than that of the dam portion 89) in a section from the third oil passage 831A to the spline fitting portion 70 on the X1 side in the X direction. That is, the rotor shaft 314 has an inner diameter r0 larger than the inner diameter r2 (see FIG. 3) of the dam portion 89 in a section from the third oil passage 831A (or the landing position P1) to the spline fitting portion 70 on the X1 side in the X direction. As a result, when the thickness t1 when the oil pool with the above-mentioned thickness t1 exceeds the dam portion 89 radially inward on the X2 side in the X direction is set to the maximum thickness (=r0-r2), the oil pool can extend to the spline fitting portion 70 on the X1 side in the X direction in a state of having the maximum thickness. In this case, by arranging multiple protruding portions forming the spline fitting portion 70 along the circumferential direction, they function as dam portions similar to the dam portion 89, and can maintain the oil reservoir of thickness t1 at the maximum thickness.

[0057] In this manner, according to the present embodiment, the spline fitting portion 70 comes into axial contact with the oil pool having the thickness t1, and can receive a stable supply of oil forming the oil pool. Also, the oil pool having the thickness t1 can increase in thickness up to a maximum thickness according to the inner diameter r2 of the dam portion 89, and therefore oil can be steadily supplied to the spline fitting portion 70 extending radially inward relative to the inner circumferential surface of the rotor shaft 314 having the inner diameter r0.

[0058] In particular, in this embodiment, as described above, the large diameter r1 (see FIGS. 5 and 6) of the female spline 71 of the spline fitting portion 70 is set to be larger than the inner diameter r2 of the dam portion 89. When the large diameter r1 of the female spline 71 of the spline fitting portion 70 is larger than the inner diameter r2 of the dam portion 89, the large diameter surface 711 of the female spline 71 of the spline fitting portion 70 is located radially outward of the innermost diameter position of the dam portion 89. This makes it easier for the oil level that accumulates on the inner circumferential surface of the rotor shaft 314 to exceed the large diameter surface 711 of the female spline 71 of the spline fitting portion 70 radially inward.

[0059] As a result, oil that accumulates on the inner peripheral surface of the rotor shaft 314 can permeate between the large diameter surface 711 of the female spline 71 of the spline fitting portion 70 and the large diameter surface 721 of the input shaft 31 (i.e., the mating surface between the large diameters). Also, the female spline 71 and the male spline 72 themselves are lubricated by a small amount of oil that leaks into the spline fitting portion 70, which is a clearance fit (for example, oil that is pushed out radially inward from within the gap as the gap between the tooth surfaces of the female spline 71 and the male spline 72 decreases, or oil that moves vertically downward as the rotation of the rotor 310 decreases).

[0060] In this way, according to this embodiment, the spline fitting portion 70 can be stably lubricated by the oil supplied from the X2 side in the X direction of the rotor shaft 314 (i.e., the oil supplied through the cover oil passage 80), so the need to form a separate oil passage on the counter gear mechanism 4 side for lubricating the spline fitting portion 70 can be reduced. As a result, for example, as shown in FIG. 2, the input shaft 31 can be realized by a solid rotating shaft member, and in this case, the processing cost of the input shaft 31 can be reduced compared to the case where the input shaft 31 is realized by a hollow rotating shaft member (i.e., a rotating shaft member having a hollow interior that forms an oil passage). Note that the input shaft 31 can also be realized by a hollow rotating shaft member, and in this respect, the degree of freedom in designing the input shaft 31 can be increased.

[0061] 7 and 8, a fitting portion between the rotor shaft 314 and the input shaft 31 that can be realized instead of the above-mentioned spline fitting portion 70 will be described as a modification of the above-mentioned embodiment. In the following, components that may be similar to those in the above-mentioned embodiment will be given the same reference numerals and descriptions thereof may be omitted.

[0062] Fig. 7 is a cross-sectional view showing a fitting portion 70A according to a first modified example, and is a cross-sectional view of a range corresponding to Fig. 5. Fig. 7A is an enlarged view of a portion Q4 in Fig. 7. The fitting portion 70A according to the first modified example includes a spline fitting portion 701 and a non-spline fitting portion 702, and the non-spline fitting portion 702 is set on the X1 side of the spline fitting portion 701 in the X-direction. Unlike the above-described spline fitting portion 70, the spline fitting portion 701 may be in the form of, for example, tooth surface fitting rather than a large diameter fitting. The non-spline fitting portion 702 may be a fitting portion that does not involve meshing of convex ridge portions with each other (a fitting portion by clearance fitting).

[0063] In this modification, the large diameter r3 of the female spline 71A of the rotor shaft 314A forming the spline fitting portion 701 is set to be larger than the inner diameter r2 of the dam portion 89. As a result, similar to the above-described embodiment, oil collected on the inner peripheral surface of the rotor shaft 314 can be permeated between the large diameter surface 711A of the female spline 71A of the spline fitting portion 701 and the large diameter surface 721A (see FIG. 7A) of the male spline 72A of the input shaft 31A. In addition, the oil leaking into the gap between the female spline 71A of the spline fitting portion 701 and the male spline 72A of the input shaft 31A also realizes lubrication of the female spline 71A and the male spline 72A themselves. In addition, the oil leaking into the gap in the spline fitting portion 701 toward the X-direction X1 also realizes lubrication of the non-spline fitting portion 702.

[0064] In this modified example, as shown in Fig. 7A, when the major diameter r3' (= the outer diameter of the large diameter surface 721A) of the male spline 72A of the input shaft 31A is significantly smaller than the major diameter r3 of the female spline 71A of the rotor shaft 314A, the major diameter r3' of the male spline 72A may be set to be larger than the inner diameter r2 of the dam portion 89. In this case, the above-mentioned effects can still be obtained.

[0065] FIG. 8 is a cross-sectional view showing a spline fitting portion 70B according to a second modified example, and is a cross-sectional view of a range corresponding to FIG.

[0066] The spline fitting portion 70B according to the second modified example is realized by the rotor shaft 314B and the input shaft 31B rotatably supported by two bearings 241A, 241B. Specifically, in the above-described embodiment, the rotor shaft 314 and the input shaft 31 are supported by a common bearing 241 at the end portion related to the spline fitting portion 70, whereas in this modified example, the rotor shaft 314B and the input shaft 31B are supported by two bearings 241A, 241B, respectively, at the end portion related to the spline fitting portion 70B.

[0067] In this modified example as well, the major diameter r4 of the female spline 71B (and the major diameter of the male spline of the input shaft 31B) that forms the spline fitting portion 70B is set to be larger than the inner diameter r2 of the dam portion 89. This provides the same effects as in the above-described embodiment.

[0068] Although each embodiment has been described above in detail, it is not limited to the specific embodiment, and various modifications and changes are possible within the scope of the claims. It is also possible to combine all or a plurality of the components of the above-mentioned embodiments. Furthermore, among the effects of each embodiment, the effects related to the dependent claims are additional effects that are distinguished from the generic concept (independent claim).

[0069] For example, in the embodiment described above, the first oil passage 81 and the second oil passage 82 are formed by the cover member 252, but at least one of the first oil passage 81 and the second oil passage 82 may be formed by a tubular member separate from the cover member 252. For example, the first oil passage 81 may be realized by a hollow tubular member separate from the cover member 252. In this case, the second oil passage 82 may be realized by forming a radial hole in the hollow tubular member. Also, the second oil passage 82 may be omitted. [Explanation of symbols]

[0070] 1... rotating electric machine, 7... power transmission mechanism, 31, 31A, 31B... input shaft (rotating shaft member), 320... stator, 310... rotor, 314... rotor shaft, 314A... hollow interior, 252... cover member (oil passage forming member), 71... female spline, 72, 72A... male spline, 721, 721A... large diameter surface, 89... dam portion

Claims

1. A stator; a rotor having a hollow rotor shaft; an oil passage forming member that forms an oil passage for supplying oil to a hollow interior of the rotor shaft, the rotor shaft has, on an inner peripheral surface thereof, a dam portion that protrudes radially inward over the entire circumferential direction, and a female spline that meshes with a male spline of a rotating shaft member for transmitting rotational torque, the oil passage supplies oil between the dam portion and the female spline in the axial direction, an inner diameter of the dam portion is smaller than a major diameter of the female spline of the rotor shaft; The rotating electric machine, wherein oil accumulated between the dam portion and the female spline comes into contact with the female spline.

2. the oil passage forming member extends from an axial opening of the rotor shaft into a hollow interior of the rotor shaft on an axial side opposite to a side on which the female spline is formed, The rotating electric machine according to claim 1 , wherein the dam portion is provided at a position overlapping the oil passage forming member when viewed in a radial direction of the rotor shaft.

3. 3 . The rotating electric machine according to claim 1 , wherein the rotor shaft has an oil hole passing therethrough in a radial direction in an axial section between the female spline and the dam portion.

4. 4. The rotating electric machine according to claim 3, wherein the rotor shaft has an inner diameter larger than an inner diameter of the dam portion over an entire length of a section between the female spline and the oil hole in the axial direction.

5. A rotating electric machine according to any one of claims 1 to 4, a power transmission mechanism including the rotating shaft member fitted to the rotor shaft, the power transmission mechanism transmitting power based on a rotational torque generated by the rotating electric machine to wheels via the rotating shaft member, A vehicle drive device, wherein the rotating shaft member is solid.

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