Oil pump shaft structure

Abstract

To provide an oil pump shaft structure which facilitates positioning of an oil pump shaft in an axial direction relative to a motor and an oil pump to improve assemblability of the oil pump shaft in the oil pump shaft connected to a rotor shaft of the motor and the oil pump disposed coaxially with the rotor shaft.SOLUTION: An oil pump shaft structure has an oil pump shaft 18 which connects a drive motor 10 with an oil pump 31. The oil pump shaft 18 includes: a shaft part 18C rotatably supported by a through hole 5e of a side cover 5; an engagement part 18A configured to engage with a rotor shaft 10C; an engagement part 18B configured to engage with the oil pump 31; an oil passage hole 18e which penetrates through a shaft center of the oil pump shaft 18 to allow an oil to flow therethrough; and a flange part 18D which protrudes from the oil pump shaft 18 to the radial outer side so as to contact with an end surface in an axial direction of the rotor shaft 10C.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an oil pump shaft structure. [Background technology]

[0002] BACKGROUND ART Conventionally, there is known a drive device in which an oil pump is housed in a cover attached to a main body, and the oil pump is rotationally driven by an oil pump drive shaft (see Patent Document 1).

[0003] The oil pump of the drive device described in Patent Document 1 is arranged coaxially with the rotor shaft of the rotating electric machine, and the oil pump drive shaft is rotationally driven by the input shaft of the engine or the rotor shaft of the rotating electric machine. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-89636 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the drive device described in Patent Document 1, when assembling the oil pump drive shaft to the rotor shaft of the rotating electric machine and the oil pump, no consideration is given to a configuration that can position the oil pump shaft in the axial direction to improve the ease of assembling the oil pump shaft.

[0006] The present invention has been made in light of the above-mentioned circumstances, and aims to provide an oil pump shaft structure for an oil pump shaft connected to a rotor shaft of a motor and an oil pump arranged coaxially with the rotor shaft, which facilitates axial positioning of the oil pump shaft relative to the motor and oil pump, thereby improving the ease of assembly of the oil pump shaft. [Means for solving the problem]

[0007] The present invention provides an oil pump shaft structure that connects a rotor shaft of a motor and an oil pump arranged coaxially with the rotor shaft and transmits rotation of the rotor shaft to the oil pump, the oil pump shaft being rotatably supported in a case member, the case member having a through hole and a wall portion separating the motor and the oil pump, the oil pump shaft comprising: a shaft portion rotatably supported in the through hole; a first engaging portion provided at one end of the oil pump shaft and engaging with the rotor shaft so as to rotate integrally with the rotor shaft; a second engaging portion provided at the other end of the oil pump shaft and engaging with the oil pump so as to rotate integrally with the oil pump; an oil passage hole that passes through the center of the shaft from one end to the other end of the oil pump shaft and through which oil flows; and a flange portion that is provided closer to the rotor shaft than the shaft portion and protrudes radially outward from the oil pump shaft so as to abut against the axial end face of the rotor shaft. [Effects of the Invention]

[0008] Thus, according to the present invention, in an oil pump shaft connected to a rotor shaft of a motor and an oil pump arranged coaxially with the rotor shaft, the axial positioning of the oil pump shaft relative to the motor and oil pump can be facilitated, thereby improving the ease of assembly of the oil pump shaft. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a vertical cross-sectional view of a drive unit equipped with an oil pump shaft structure according to one embodiment of the present invention. [Figure 2] FIG. 2 is an enlarged vertical cross-sectional view of an oil pump shaft and its surroundings in a drive device equipped with an oil pump shaft structure according to one embodiment of the present invention. [Figure 3] FIG. 3 is an exploded perspective view of a rotor shaft, an oil pump shaft, and an inner rotor of an oil pump shaft structure according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] An oil pump shaft structure according to one embodiment of the present invention has an oil pump shaft that connects a rotor shaft of a motor and an oil pump arranged coaxially with the rotor shaft and transmits rotation of the rotor shaft to the oil pump, the oil pump shaft being rotatably supported in a case member, the case member having a through hole and a wall portion separating the motor and the oil pump, the oil pump shaft having a shaft portion rotatably supported in the through hole, a first engaging portion provided at one end of the oil pump shaft and engaging with the rotor shaft so as to rotate integrally with the rotor shaft, a second engaging portion provided at the other end of the oil pump shaft and engaging with the oil pump so as to rotate integrally with the oil pump, an oil passage hole that passes through the center of the oil pump shaft from one end to the other end and through which oil flows, and a flange portion that is provided closer to the rotor shaft than the shaft portion and protrudes radially outward from the oil pump shaft so as to abut the axial end face of the rotor shaft.

[0011] As a result, the oil pump shaft structure according to one embodiment of the present invention facilitates the axial positioning of the oil pump shaft relative to the motor and oil pump in an oil pump shaft connected to the rotor shaft of a motor and an oil pump arranged coaxially with the rotor shaft, thereby improving the ease of assembly of the oil pump shaft. [Example]

[0012] An oil pump shaft structure according to an embodiment of the present invention will now be described with reference to the drawings. 1 to 3 are diagrams showing an oil pump shaft structure according to one embodiment of the present invention.

[0013] 1 to 3, the up-down, front-rear, left-right directions are defined as follows: the axial direction of the oil pump shaft is the horizontal direction, the axial direction of the oil pump shaft is the left-right direction, the direction perpendicular to the axial direction of the oil pump shaft in a horizontal plane is the front-rear direction, and the vertical direction is the up-down direction. Furthermore, the directions used in the explanations of each figure shall conform to the directions indicated by the coordinates attached to each figure.

[0014] First, the configuration will be described. 1, a drive unit 1 includes a drive case 2, which is provided with, from right to left, a right case 3, a left case 4, and a side cover 5. The drive case 2 of this embodiment constitutes a case member.

[0015] The light case 3 has a right side wall 3A and a peripheral wall 3B. The right side wall 3A is connected to the cylinder block of the engine by bolts (not shown).

[0016] The left case 4 has a partition wall 4A and a peripheral wall 4B. The peripheral wall 3B of the right case 3 is connected to the peripheral wall 4B of the left case 4 by bolts 22A, and the side cover 5 is fastened to the peripheral wall 4B of the left case 4 by bolts (not shown).

[0017] A gear chamber 6 is formed between the right side wall 3A, the peripheral wall 3B and the partition wall 4A, and a motor chamber 7 is formed between the partition wall 4A, the peripheral wall 4B and the side cover 5.

[0018] The gear chamber 6 houses a reduction gear mechanism 8. The reduction gear mechanism 8 includes an input shaft 15A connected to a rotor shaft 10C of the drive motor 10, a drive gear 15B provided on the input shaft 15A, and an output shaft 15C having a driven gear 15D meshing with the drive gear 15B and a drive gear 15E meshing with a final driven gear 9A of the differential device 9.

[0019] A drive motor 10 is housed in the motor chamber 7. A generator motor (not shown) is also housed in the motor chamber 7. The drive motor 10 of this embodiment constitutes a motor.

[0020] The drive motor 10 includes an annular stator 10A, an annular rotor 10B disposed radially inward of the stator 10A, and a rotor shaft 10C attached to the inner periphery of the rotor 10B and rotating integrally with the rotor 10B.

[0021] The drive motor 10 is connected to a battery via an inverter and a boost converter, both of which are not shown, and receives power from the battery and the power generation motor to rotate the rotor shaft 10C.

[0022] As a result, the driving force of the drive motor 10 is transmitted to the reduction mechanism 8 and the differential device 9, and then transmitted from the differential device 9 to the left and right drive wheels (not shown) via the left and right drive shafts (not shown), causing the vehicle to move.

[0023] Specifically, the driving force of the drive motor 10 is transmitted from the rotor shaft 10C to the output shaft 15C via the input shaft 15A, drive gear 15B and driven gear 15D by the rotation of the rotor shaft 10C, and then transmitted from the drive gear 15E to the final driven gear 9A of the differential device 9.

[0024] The differential device 9 includes a differential case 9B, and when the final driven gear 9A rotates, the differential case 9B rotates integrally with the final driven gear 9A.

[0025] A differential mechanism (not shown) is provided inside the differential case 9B, and when the differential case 9B rotates integrally with the final driven gear 9A, the differential mechanism distributes the driving force of the drive motor 10 to the left and right drive wheels via the left and right drive shafts.

[0026] A parking gear 15F is attached to the input shaft 15A so as to be rotatable integrally therewith, and the parking gear 15F engages with a parking pole (not shown) to restrict the rotation of the input shaft 15A and maintain the vehicle in a stopped state.

[0027] A bearing support portion 4a is formed in the partition wall 4A, and the right end portion of the rotor shaft 10C is rotatably supported by the bearing support portion 4a via a bearing 20A.

[0028] A bearing support portion 5a is formed on the side cover 5, and the left end portion of the rotor shaft 10C is rotatably supported by the bearing support portion 5a via a bearing 20B.

[0029] Specifically, the rotor shaft 10C has a large-diameter cylindrical portion 10a that fits into the rotor 10B, a right-side small-diameter cylindrical portion 10b that protrudes to the right from the large-diameter cylindrical portion 10a and has a smaller diameter than the large-diameter cylindrical portion 10a, and a left-side small-diameter cylindrical portion 10c that protrudes to the left from the large-diameter cylindrical portion 10a and has a smaller diameter than the large-diameter cylindrical portion 10a.

[0030] The rotor shaft 10C has a right small diameter cylindrical portion 10b rotatably supported by the bearing support portion 4a via a bearing 20A, and a left small diameter cylindrical portion 10c rotatably supported by the bearing support portion 5a via a bearing 20B.

[0031] 2 and 3, an engagement groove 10d is formed in the left end of the left small-diameter cylindrical portion 10c, and the engagement groove 10d extends axially around the axis of the left small-diameter cylindrical portion 10c. As shown in Fig. 3, the engagement groove 10d is formed in a two-flat shape having a pair of flat inner surfaces 10m, 10n.

[0032] In detail, the flat inner surfaces 10m, 10n consist of a pair of flat surfaces that are the same distance from the axis, parallel to the axis, and parallel to each other, and the engagement groove 10d is formed in the shape of a hole extending in the axial direction and having the flat inner surfaces 10m, 10n.

[0033] 1 and 2, a first oil passage hole 10e is formed on the left side of the left small-diameter cylindrical portion 10c and the left side of the large-diameter cylindrical portion 10a, and the first oil passage hole 10e is connected to the engagement groove 10d. A second oil passage hole 10f is formed in the large-diameter cylindrical portion 10a, and the second oil passage hole 10f is connected to the first oil passage hole 10e.

[0034] As shown in FIG. 1, an engagement hole 10g is formed on the right side of the right small-diameter cylindrical portion 10b and the large-diameter cylindrical portion 10a.

[0035] The engagement hole 10g is a splined hole with splines formed on its inner diameter. The left end of the input shaft 15A is a splined shaft, and the left end of the input shaft 15A is inserted into the engagement hole 10g and the splines mesh with each other, thereby connecting the rotor shaft 10C and the input shaft 15A so that they can rotate together.

[0036] A first radial hole 10h is formed in the first oil passage hole 10e. The first radial hole 10h communicates the first oil passage hole 10e with the outside of the left small-diameter cylindrical portion 10c, and the first radial hole 10h opens toward the coil end of the stator 10A.

[0037] A second radial hole 10i is formed in the second oil passage hole 10f. The second radial hole 10i communicates the second oil passage hole 10f with the outside of the right small-diameter cylindrical portion 10b, and extends obliquely from near the deep end of the spline hole toward the bearing 20A and opens at the inner diameter position of the coil end of the stator 10A. In this embodiment, the first radial hole 10h and the second radial hole 10i constitute a radial hole.

[0038] 2, a trochoid oil pump 31 is provided on the side cover 5. A pump rotor accommodating groove 5b is formed in the side cover 5, and an inner rotor 31A and an outer rotor 31B of the oil pump 31 are accommodated in the pump rotor accommodating groove 5b.

[0039] A pump cover 17 is attached to the side cover 5 with bolts (not shown), and the pump rotor accommodating groove 5b is closed by the pump cover 17. As a result, the inner rotor 31A and the outer rotor 31B are accommodated in the pump rotor accommodating groove 5b.

[0040] The inner rotor 31A is connected to the rotor shaft 10C via the oil pump shaft 18, and rotates in conjunction with the rotor shaft 10C. The outer rotor 31B is provided radially outward of the inner rotor 31A, and rotates in conjunction with the rotation of the inner rotor 31A.

[0041] In the trochoid oil pump 31, multiple internal teeth formed on the outer rotor 31B come into contact with multiple external teeth 31a (see Figure 3) formed on the inner rotor 31A, thereby forming multiple working chambers that store oil between the external teeth 31a and the internal teeth.

[0042] The side cover 5 and the pump cover 17 are respectively formed with an intake port 5c and an intake passage 17a which communicate with the working chamber, and a discharge port 5d and a discharge passage 17b which communicate with the working chamber.

[0043] In the oil pump 31, when the driving force of the drive motor 10 is transmitted from the rotor shaft 10C to the inner rotor 31A via the oil pump shaft 18, the inner rotor 31A and the outer rotor 31B rotate in one direction, causing the volume of the working chamber to increase and decrease continuously, thereby drawing oil from the suction passage 17a through the suction port 5c into the working chamber, and discharging the oil pressurized by the working chamber to the discharge port 5d and the discharge passage 17b.

[0044] An oil passage communicating with the discharge passage 17b is formed in the side cover 5, and oil discharged from the oil pump 31 is supplied to the oil tank 19 (see FIG. 1) from the discharge port 5d and the discharge passage 17b through the oil passage.

[0045] 1, oil tank 19 is provided above drive motor 10 and supplies oil to the coil ends of stator 10A of drive motor 10. As a result, stator 10A is cooled by the oil.

[0046] 3, an engagement portion 18A is formed at the right end of the oil pump shaft 18. The engagement portion 18A is formed in a two-flat shape having a pair of flat outer surfaces 18a, 18b. In detail, the flat outer surfaces 18a, 18b are a pair of flat surfaces that are the same distance from the axis, parallel to the axis, and parallel to each other, and the engagement portion 18A is formed in a shaft shape that extends in the axial direction and has the flat outer surfaces 18a, 18b.

[0047] Engagement portion 18A is inserted into engagement groove 10d in left small-diameter cylindrical portion 10c of rotor shaft 10C, and flat outer surfaces 18a, 18b engage with flat inner surfaces 10m, 10n of engagement groove 10d. This prevents relative rotation between rotor shaft 10C and oil pump shaft 18, and power is transmitted from rotor shaft 10C to oil pump shaft 18, causing rotor shaft 10C and oil pump shaft 18 to rotate integrally.

[0048] An engagement hole 31b is formed in the inner rotor 31A, and the engagement hole 31b is formed in a two-face shape having a pair of flat inner surfaces 31c, 31d.

[0049] In detail, the flat inner surfaces 31c and 31d consist of a pair of flat surfaces that are the same distance from the axis, parallel to the axis, and parallel to each other, and the engagement hole 31b is formed in the shape of a hole extending in the axial direction and having the flat inner surfaces 31c and 31d.

[0050] An engagement portion 18B is formed at the left end of the oil pump shaft 18. The engagement portion 18B is formed in a two-flat shape having a pair of flat outer surfaces 18c, 18d. In detail, the flat outer surfaces 18c, 18d are a pair of flat surfaces that are the same distance from the axis, parallel to the axis, and parallel to each other, and the engagement portion 18B is formed in the shape of a hole that extends in the axial direction and has the flat outer surfaces 18c, 18d.

[0051] Engagement portion 18B is inserted into engagement hole 31b of inner rotor 31A, and flat outer surfaces 18c, 18d engage with flat inner surfaces 31c, 31d of engagement hole 31b. This prevents relative rotation between inner rotor 31A and oil pump shaft 18, and power is transmitted from oil pump shaft 18 to inner rotor 31A, causing inner rotor 31A and oil pump shaft 18 to rotate integrally.

[0052] In this embodiment, the engagement portion 18A constitutes a first engagement portion provided at the right end (one end) of the oil pump shaft 18, and the engagement portion 18B constitutes a second engagement portion provided at the left end (other end) of the oil pump shaft 18.

[0053] The side cover 5 of this embodiment forms a wall that separates the oil pump 31 and the drive motor 10 .

[0054] 2, a through hole 5e is formed in the side cover 5. The oil pump shaft 18 has a shaft portion 18C formed between the engagement portions 18A and 18B, and the shaft portion 18C is rotatably supported in the through hole 5e. In the drive unit 1 of this embodiment, the rotor shaft 10C, the oil pump 31, and the oil pump shaft 18 are coaxially arranged.

[0055] In the side cover 5, the intake port 5c and the discharge port 5d are formed radially outward from the through hole 5e, and the intake port 5c, the discharge port 5d and the through hole 5e are formed at the same position in the axial direction of the oil pump shaft 18.

[0056] In other words, the intake port 5c, the discharge port 5d and the through hole 5e are aligned in a radial direction perpendicular to the axial direction of the oil pump shaft 18.

[0057] An oil passage hole 18e is formed in the oil pump shaft 18. The oil passage hole 18e penetrates the shaft center from the right end to the left end of the oil pump shaft 18. In other words, the oil passage hole 18e is open at both the right end and the left end of the oil pump shaft 18.

[0058] The right end of the oil passage hole 18e communicates with the first oil passage hole 10e of the left small diameter cylindrical portion 10c, and the left end of the oil passage hole 18e communicates with the discharge passage 17b of the pump cover 17.

[0059] A first radial hole 18f and a second radial hole 18g are formed in the oil pump shaft 18. The first radial hole 18f and the second radial hole 18g extend radially outward from the oil passage hole 18e and open outward, connecting the oil passage hole 18e with the outside of the oil pump shaft 18.

[0060] The first radial hole 18f is open between the through hole 5e and the shaft portion 18C. The second radial hole 18g is formed closer to the rotor shaft 10C than the shaft portion 18C, and is formed at a position outside the through hole 5e and opens toward the bearing 20B.

[0061] Oil discharged from the oil pump 31 through the discharge port 5d to the discharge passage 17b is supplied to the oil tank 19 through the oil passage, and is also supplied through the discharge passage 17b to the oil passage hole 18e of the oil pump shaft 18 and flows through the oil passage hole 18e.

[0062] The oil flowing through the oil passage hole 18e is supplied from the first radial hole 18f to between the through hole 5e and the shaft portion 18C. As a result, an oil film is formed between the through hole 5e and the shaft portion 18C, and the shaft portion 18C is rotatably supported in the through hole 5e via the oil film.

[0063] The oil flowing through the oil passage hole 18e is discharged from the second radial hole 18g and flows along the inner surface of the side cover 5 to be supplied to the bearing 20B, whereby the bearing 20B is lubricated by the oil.

[0064] The oil flowing through the oil passage hole 18e flows to the first oil passage hole 10e and is supplied to the coil end of the stator 10A through the first radiation hole 10h.

[0065] As a result, the coil ends are cooled from the outside by oil supplied from oil tank 19, and from the inside by oil supplied from first radiation holes 10h. As a result, the cooling performance of stator 10A can be more effectively improved.

[0066] Furthermore, the oil flowing through the first oil passage hole 10e is supplied to the bearing 20A from the second radial hole 10i and falls onto the coil ends of the stator 10A, thereby lubricating the bearing 20A with the oil and cooling the coil ends of the stator 10A.

[0067] The oil pump shaft 18 is formed with a flange 18D, which is provided at the left end of the engagement portion 18A and closer to the rotor shaft 10C than the shaft portion 18C.

[0068] The flange portion 18D projects radially outward from the oil pump shaft 18 and abuts against the left end face (end face) of the rotor shaft 10C in the axial direction.

[0069] The flange portion 18D is formed with a larger diameter than the open end of the engagement groove 10d in the left small-diameter cylindrical portion 10c of the oil pump shaft 18, and by abutting against the left axial end face of the rotor shaft 10C, the oil pump shaft 18 is positioned in the axial direction so that it does not enter excessively into the engagement groove 10d.

[0070] Specifically, the flange portion 18D is located on the left end edge of the flat outer surfaces 18a, 18b, and by forming the flat outer surfaces 18a, 18b, the flange portion 18D protrudes radially outward from the flat outer surfaces 18a, 18b.

[0071] The flange portion 18D is formed with a diameter larger than the inner diameter of the through hole 5e of the side cover 5, and when the oil pump shaft 18 attempts to pass through the through hole 5e and slip out, it abuts against the outer peripheral edge of the through hole 5e, preventing the oil pump shaft 18 from passing through the side cover 5 and slipping out to the outside of the drive case 2.

[0072] A step 18h is formed on the left end of the oil pump shaft 18. Flat outer surfaces 18c, 18d are formed on the oil pump shaft 18 to the left of the step 18h. In detail, the step 18h is located on the right end edges of the flat outer surfaces 18c, 18d, and by forming the flat outer surfaces 18c, 18d, the step 18h protrudes radially outward from the flat outer surfaces 18c, 18d.

[0073] The step portion 18h abuts against the right end face (end face) of the inner rotor 31A, and positions the oil pump shaft 18 in the axial direction so that the oil pump shaft 18 does not enter excessively into the engagement hole 31b of the inner rotor 31A.

[0074] A resolver 21A is attached to the side cover 5 by bolts 22B, and a resolver rotor 21B is attached to the left small diameter cylindrical portion 10c.

[0075] The resolver 21A detects the resolver rotor 21B to detect the rotation angle of the rotor shaft 10C.

[0076] Next, a method for assembling the oil pump shaft 18 will be described. With the side cover 5 not attached to the left case 4 housing the drive motor 10, the right end of the oil pump shaft 18 is inserted into the engagement groove 10d of the left small diameter cylindrical portion 10c of the rotor shaft 10C.

[0077] That is, the engaging portion 18A of the oil pump shaft 18 is inserted into the engaging groove 10d of the left small diameter cylindrical portion 10c of the rotor shaft 10C, and the flat outer surfaces 18a, 18b are engaged with the flat inner surfaces 10m, 10n of the engaging groove 10d.

[0078] In this state, the side cover 5 is attached so as to cover the left case 4. When attaching the side cover 5, the oil pump shaft 18 is inserted into the through-hole 5e of the side cover 5, and the oil pump shaft 18 penetrates the side cover 5 with the engaging portion 18B protruding into the internal space of the pump rotor accommodating groove 5b.

[0079] Next, the inner rotor 31A and outer rotor 31B are attached to the pump rotor groove 5b, and the left end of the oil pump shaft 18 protruding from the side cover 5 into the pump rotor groove 5b is engaged with the engagement hole 31b of the inner rotor 31A.

[0080] That is, the engaging portion 18B of the oil pump shaft 18 is inserted into the engaging hole 31b of the inner rotor 31A, and the flat outer surfaces 18c and 18d are engaged with the flat inner surfaces 31c and 31d of the engaging hole 31b.

[0081] Next, after attaching the side cover 5 to the left case 4 with bolts, the seal member 25 is placed in the seal groove 5h formed in the side cover 5 at the mating surface between the side cover 5 and the pump cover 17, and the pump cover 17 is attached to the side cover 5 with bolts, completing the assembly of the oil pump shaft 18.

[0082] As described above, the oil pump shaft structure of this embodiment has an oil pump shaft 18 that connects the rotor shaft 10C of the drive motor 10 to the oil pump 31 arranged coaxially with the rotor shaft 10C and transmits the rotation of the rotor shaft 10C to the oil pump 31.

[0083] The oil pump shaft 18 is rotatably supported by the drive case 2, and the drive case 2 has a through hole 5e and is provided with a side cover 5 that separates the drive motor 10 and the oil pump 31.

[0084] The oil pump shaft 18 has a shaft portion 18C that is rotatably supported in the through hole 5e, and an engagement portion 18A that is provided at the right end of the oil pump shaft 18 and engages with the rotor shaft 10C so as to rotate integrally with the rotor shaft 10C.

[0085] In addition, the oil pump shaft 18 is provided with an engagement portion 18B at the left end of the oil pump shaft 18 that engages with the oil pump 31 so as to rotate integrally with the oil pump 31, an oil passage hole 18e that penetrates the axial center from the right end to the left end of the oil pump shaft 18 and through which oil flows, and a flange portion 18D that is provided on the rotor shaft 10C side of the shaft portion 18C and protrudes radially outward from the oil pump shaft 18 so as to abut against the axial end face of the rotor shaft 10C.

[0086] As a result, by abutting the flange portion 18D against the left end surface of the rotor shaft 10C in the axial direction, the oil pump shaft 18 can be positioned in the axial direction so that the oil pump shaft 18 does not enter the engagement groove 10d excessively.

[0087] Therefore, the length of the oil pump shaft 18 from the flange portion 18D to the inner rotor 31A can be set with the oil pump shaft 18 inserted into the engagement groove 10d, and while inserting the oil pump shaft 18 into the through hole 5e, the engagement portion 18B of the oil pump shaft 18 can be easily positioned on the inner rotor 31A and engaged with the inner rotor 31A.

[0088] In this way, the oil pump shaft structure of this embodiment facilitates the axial positioning of the oil pump shaft 18 relative to the drive motor 10 and the oil pump 31 in the oil pump shaft 18 connected to the rotor shaft 10C of the drive motor 10 and the oil pump 31 arranged coaxially with the rotor shaft 10C, thereby improving the ease of assembly of the oil pump shaft 18.

[0089] Furthermore, in the oil pump shaft structure of this embodiment, the engaging portions 18A, 18B of the oil pump shaft 18 have a two-face width shape, so that the oil pump shaft 18 can be easily attached to the rotor shaft 10C and the inner rotor 31A, and the workability of the assembly work of the oil pump shaft 18 can be more effectively improved.

[0090] Furthermore, since the engagement portions 18A and 18B of the oil pump shaft 18 have a two-face width shape, the engagement between the oil pump shaft 18 and the rotor shaft 10C is loose, and the oil pump shaft 18 can be easily positioned in the axial direction when the drive unit 1 is actually operating after the oil pump shaft 18 is assembled.

[0091] Furthermore, when attaching the side cover 5 to the left case 4, the side cover 5 can be moved toward the left case 4 while the oil pump shaft 18 is passing through the through hole 5e, so that the oil pump shaft 18 can be used as a guide when attaching the side cover 5, improving the workability of assembling the side cover 5.

[0092] Furthermore, according to the oil pump shaft structure of this embodiment, the oil pump 31 has the inner rotor 31A with which the engaging portion 18B engages, and the oil pump shaft 18 has the step portion 18h that abuts against the end face of the inner rotor 31A.

[0093] As a result, the step portion 18h can easily position the oil pump shaft 18 in the axial direction relative to the oil pump 31, and the workability of the assembling work of the oil pump shaft 18 can be more effectively improved.

[0094] In other words, the oil pump shaft 18 can move axially until the step portion 18h abuts against the end face of the inner rotor 31A or until the flange portion 18D abuts against the left axial end face of the rotor shaft 10C, and the axial position of the oil pump shaft 18 is restricted by the step portion 18h abutting against the end face of the inner rotor 31A or the flange portion 18D abutting against the left axial end face of the rotor shaft 10C.

[0095] Furthermore, according to the oil pump shaft structure of this embodiment, the oil pump 31 has an intake port 5c that draws in oil and an exhaust port 5d that discharges oil, and the intake port 5c and the exhaust port 5d are formed in the side cover 5 radially outward of the through hole 5e.

[0096] This allows the suction port 5c, the discharge port 5d, and the through hole 5e to be formed at the same axial position on the oil pump shaft 18. Therefore, the axial length of the oil pump shaft 18 can be made shorter than when the suction port 5c, the discharge port 5d, and the through hole 5e are spaced apart in the axial direction of the oil pump shaft 18.

[0097] As a result, the length (thickness) of the side cover 5 in the axial direction of the oil pump shaft 18 can be reduced, and the drive case 2 can be made smaller.

[0098] Furthermore, according to the oil pump shaft structure of this embodiment, the rotor shaft 10C is rotatably supported on the side cover 5 via the bearing 20A, and the oil pump shaft 18 has a first radial hole 18f and a second radial hole 18g that extend radially outward from the oil passage hole 18e and connect the oil passage hole 18e to the outside of the oil pump shaft 18.

[0099] The first radial hole 18f is formed in the shaft portion 18C and supplies oil between the through hole 5e and the shaft portion 18C, and the second radial hole 18g is formed closer to the rotor shaft 10C than the shaft portion 18C and supplies oil to the bearing 20B.

[0100] This allows oil to be supplied from the first radial holes 18f between the through hole 5e and the shaft portion 18C, forming an oil film between the through hole 5e and the shaft portion 18C. Therefore, the shaft portion 18C can be rotatably supported in the through hole 5e via the oil film, and the durability of the oil pump shaft 18 can be improved.

[0101] Furthermore, oil can be supplied to the bearing 20B from the second radial hole 18g to lubricate the bearing 20B with the oil, thereby improving the durability of the bearing 20B.

[0102] The oil that lubricates the bearing 20B is supplied to the coil end of the stator 10A because the attachment portion of the resolver rotor 21B of the side cover 5 disposed on the right side of the bearing 20B protrudes toward the inner diameter side of the coil end.

[0103] Here, if the first radial hole 18f is not formed in the shaft portion 18C, it is necessary to supply oil from the discharge passage 17b of the oil pump 31 to between the through hole 5e and the shaft portion 18C.

[0104] To supply oil between the through hole 5e and the shaft portion 18C, it is necessary to increase the gap between the through hole 5e and the shaft portion 18C, which may increase oil leakage from the discharge port 5d and reduce the pumping efficiency of the oil pump 31.

[0105] In the oil pump shaft 18 of this embodiment, by forming the first radial holes 18f in the shaft portion 18C, it is not necessary to increase the gap between the through hole 5e and the shaft portion 18C, and oil leakage from the discharge port 5d can be reduced, thereby improving the pumping efficiency of the oil pump 31.

[0106] While an embodiment of the present invention has been disclosed, it will be apparent to one skilled in the art that modifications may be made thereto without departing from the scope of the present invention, and it is intended that all such modifications and equivalents be included in the following claims. [Explanation of symbols]

[0107] 2 Drive case (case component) 5 Side cover (wall) 5c Intake port 5d Discharge port 5e Through hole 10 Drive motor (motor) 10C rotor shaft 10h First radiation hole (radiation hole) 10i Second Radial Hole (Radial Hole) 18 Oil pump shaft 18A Engagement portion (first engagement portion) 18B Engagement portion (second engagement portion) 18C Shaft 18D Tsubabe 18e Oil passage hole 18h stepped section 31 Oil pump 31A inner rotor

Claims

1. An oil pump shaft structure including an oil pump shaft that connects a rotor shaft of a motor and an oil pump that is arranged coaxially with the rotor shaft and transmits rotation of the rotor shaft to the oil pump, the oil pump shaft being rotatably supported by a case member, the case member has a through hole and a wall portion separating the motor and the oil pump, The oil pump shaft a shaft portion rotatably supported in the through hole; a first engaging portion provided at one end of the oil pump shaft and engaging with the rotor shaft so as to rotate integrally with the rotor shaft; a second engaging portion provided on the other end of the oil pump shaft and engaging with the oil pump so as to rotate integrally with the oil pump; an oil passage hole that passes through the center of the oil pump shaft from one end to the other end and through which oil flows; an oil pump shaft structure comprising: a flange portion provided closer to the rotor shaft than the shaft portion and protruding radially outward from the oil pump shaft so as to abut against an axial end face of the rotor shaft.

2. the oil pump has an inner rotor with which the second engagement portion is engaged, 2. The oil pump shaft structure according to claim 1, wherein the oil pump shaft has a step portion that abuts against the end surface of the inner rotor.

3. The oil pump has a suction port for drawing oil and a discharge port for discharging oil, 3. The oil pump shaft structure according to claim 1, wherein the suction port and the discharge port are formed in the wall portion radially outward of the through hole.

4. the rotor shaft is rotatably supported by the wall portion via a bearing, the oil pump shaft has a radial hole extending radially outward from the oil passage hole and communicating the oil passage hole with the outside of the oil pump shaft, The radiation hole is a first radial hole formed in the shaft portion and configured to supply oil between the through hole and the shaft portion; 3. The oil pump shaft structure according to claim 1, further comprising a second radial hole formed closer to the rotor shaft than the shaft portion and supplying oil to the bearing.

5. the rotor shaft is rotatably supported by the wall portion via a bearing, the oil pump shaft has a radial hole extending radially outward from the oil passage hole and communicating the oil passage hole with the outside of the oil pump shaft, 4. The oil pump shaft structure according to claim 3, wherein the radial holes include a first radial hole formed in the shaft portion and supplying oil between the through hole and the shaft portion, and a second radial hole formed closer to the rotor shaft than the shaft portion and supplying oil to the bearing.

Images