Vehicle drive device

Abstract

A vehicle drive device (100) comprises: a rotating electric machine (1); a drive transmission mechanism (10) provided on a power transmission path (P) connecting a rotor shaft (122) of the rotating electric machine (1) and a wheel (W); a first hydraulic pump (71) driven by a driving force transmitted in the power transmission path (P); a second hydraulic pump (72) driven by a driving force source (72a) independent of the power transmission path (P); a first oil path (91) for supplying oil discharged from the first hydraulic pump (71) to a rotor bearing (B1) supporting the rotor shaft (122) in a rotatable manner; and a second oil path (92) for supplying oil discharged from the second hydraulic pump (72) to an inner peripheral surface (122d) of the rotor shaft (122).

Description

Technical Field

[0001] The present invention relates to a vehicle drive device having a rotating electric machine serving as a driving force source for wheels, a drive transmission mechanism arranged in a power transmission path connecting the rotating electric machine and the wheels, a first hydraulic pump driven by the driving force transmitted in the power transmission path, and a second hydraulic pump driven by a driving force source independent of the power transmission path. Background Art

[0002] An example of such a vehicle drive device is disclosed in the following Patent Document 1. In the following description of the background art, the reference numerals of Patent Document 1 are cited in parentheses.

[0003] The vehicle drive device (1) of Patent Document 1 includes a first oil passage (91) through which oil discharged from a first hydraulic pump (51) flows, and a second oil passage (92) through which oil discharged from a second hydraulic pump (52) flows.

[0004] Patent Document 1: International Publication No. 2018 / 061443 (FIG. 6)

[0005] In the vehicle drive device (1) of Patent Document 1, the first oil circuit (91) includes an inner cooling oil circuit (93) for cooling a rotating electric machine (10) from the inner side in the radial direction (R), and the second oil circuit (92) includes an outer cooling oil circuit (65) for cooling the rotating electric machine (10) from the outer side in the radial direction (R). That is, the first oil circuit (91) and the second oil circuit (92) each include an oil circuit for cooling the rotating electric machine (10). Therefore, even when cooling of the rotating electric machine (10) is not required, oil is supplied to at least one of the inner cooling oil circuit (93) and the outer cooling oil circuit (65).

[0006] Furthermore, in the vehicle drive device (1) of Patent Document 1, although lubricating oil is supplied to the bearing (B) that rotatably supports the rotating parts such as the rotor shaft (16) of the rotating electric machine (10), there is no regulation on the timing of lubricating the bearing (B). That is, in the vehicle drive device (1) of Patent Document 1, oil is often supplied to the bearing (B) even when lubrication of the bearing (B) is not required.

[0007] As described above, in the vehicle drive device (1) of Patent Document 1, the energy required to drive the hydraulic pumps (51, 52) for supplying unnecessary oil becomes unnecessary loss, and there is a problem that the energy efficiency of the vehicle drive device (1) is reduced accordingly.

[0008] Therefore, it is desired to realize a vehicle drive device that can suppress energy loss caused by driving an unnecessary hydraulic pump to a minimum and improve energy efficiency. Summary of the invention

[0009] In view of the above, the characteristic structure of the vehicle drive device is the following aspects, which has:

[0010] A rotating electric machine, which is a driving force source for wheels, and includes a stator core, a rotor core rotatably supported relative to the stator core, and a cylindrical rotor shaft connected to the rotor core so as to rotate integrally therewith;

[0011] a drive transmission mechanism provided in a power transmission path connecting the rotor shaft and the wheel;

[0012] a first hydraulic pump driven by the driving force transmitted in the power transmission path;

[0013] a second hydraulic pump driven by a driving force source independent of the power transmission path;

[0014] a first oil passage that supplies oil discharged from the first hydraulic pump to a rotor bearing that rotatably supports the rotor shaft; and

[0015] The second oil passage supplies the oil discharged from the second hydraulic pump to the inner peripheral surface of the rotor shaft.

[0016] According to this characteristic structure, a first oil circuit and a first hydraulic pump are provided as a hydraulic circuit for lubricating a rotor bearing that supports the rotor shaft of the rotating electric machine so that it can rotate, and a second oil circuit and a second hydraulic pump are provided as a hydraulic circuit for cooling the inner circumferential surface of the rotor shaft. As a result, the lubrication of the rotor bearing and the cooling of the inner circumferential surface of the rotor shaft can be performed independently. Therefore, when the vehicle is stopped, when the lubrication of the rotor bearing is not required, the supply of oil from the first hydraulic pump to the rotor bearing can be stopped, and when the temperature of the rotating electric machine is low, when the cooling of the inner circumferential surface of the rotor shaft is not required, the supply of oil from the second hydraulic pump to the inner circumferential surface of the rotor shaft can be stopped. That is, when the supply of oil to either the inner circumferential surface of the rotor shaft or the rotor bearing is not required, the supply of oil to both of them can be avoided. As a result, the energy loss caused by the driving of the unnecessary hydraulic pump can be suppressed to a small level, and the energy efficiency of the vehicle drive device can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a cross-sectional view along the axial direction of the vehicle drive device according to the embodiment.

[0018] Figure 2 It is a schematic diagram of a vehicle drive device according to an embodiment.

[0019] Figure 3It is a diagram showing a part of a first oil passage and a second oil passage of the vehicle drive device according to the embodiment.

[0020] Figure 4 It is a diagram showing a part of a first oil passage of the vehicle drive device according to the embodiment. DETAILED DESCRIPTION

[0021] Hereinafter, a vehicle drive device 100 according to an embodiment will be described with reference to the accompanying drawings. Figure 1 as well as Figure 2 As shown, the vehicle drive device 100 includes a rotary electric machine 1 that is a driving force source for the wheels W, and a drive transmission mechanism 10 that is provided in a power transmission path P that connects the rotary electric machine 1 and the wheels W. In the present embodiment, the rotary electric machine 1 and the drive transmission mechanism 10 are accommodated in a housing 2. In addition, in the present embodiment, the drive transmission mechanism 10 includes an input member 3, a counter gear mechanism 4, a differential gear mechanism 5, a first output member 61, and a second output member 62.

[0022] The rotating electric machine 1 is arranged on the first axis A1 as the rotation axis thereof. In the present embodiment, the input member 3 is also arranged on the first axis A1. The reverse gear mechanism 4 is arranged on the second axis A2 as the rotation axis thereof. The differential gear mechanism 5 is arranged on the third axis A3 as the rotation axis thereof. In the present embodiment, the first output member 61 and the second output member 62 are also arranged on the third axis A3. The first axis A1, the second axis A2 and the third axis A3 are different imaginary axes and are arranged parallel to each other.

[0023] In the following description, the direction parallel to the above-mentioned axes A1 to A3 is referred to as the "axial direction L" of the vehicle drive device 100. Moreover, in the axial direction L, the side where the rotary electric machine 1 is arranged relative to the input member 3 is referred to as the "axial first side L1", and the opposite side is referred to as the "axial second side L2". In addition, the direction orthogonal to each of the above-mentioned first axis A1, second axis A2, and third axis A3 is referred to as the "radial direction R" with respect to each axis as a reference. In addition, when it is not necessary to distinguish which axis is used as a reference, or when it is clear which axis is used as a reference, it may be simply referred to as the "radial direction R".

[0024] like Figure 1As shown, in the present embodiment, the housing 2 includes a peripheral wall portion 21, a first side wall portion 22, a second side wall portion 23, and a partition wall portion 24. The peripheral wall portion 21 is formed in a cylindrical shape surrounding the outer side of the radial direction R of the rotating electrical machine 1 and the drive transmission mechanism 10. The first side wall portion 22 and the second side wall portion 23 are formed to extend along the radial direction R. The first side wall portion 22 is fixed to the end portion of the axial first side L1 of the peripheral wall portion 21 in a manner that closes the opening of the axial first side L1 of the peripheral wall portion 21. The second side wall portion 23 is fixed to the end portion of the axial second side L2 of the peripheral wall portion 21 in a manner that closes the opening of the axial second side L2 of the peripheral wall portion 21.

[0025] The partition wall portion 24 is a space on the inner side of the radial direction R of the peripheral wall portion 21, and is formed to divide the space between the first side wall portion 22 and the second side wall portion 23 in the axial direction L. In the present embodiment, the rotating electrical machine 1 is arranged between the partition wall portion 24 and the first side wall portion 22. Furthermore, the drive transmission mechanism 10 is arranged between the partition wall portion 24 and the second side wall portion 23.

[0026] The rotating electrical machine 1 has a stator 11 and a rotor 12. Here, in the present application, the term "rotating electrical machine" is used as a concept including a motor (electric motor), a generator, and a motor / generator that functions as both a motor and a generator as necessary.

[0027] The stator 11 has a stator core 111 fixed to a non-rotating member (for example, a housing 2). The rotor 12 has a rotor core 121 that can rotate relative to the stator 11 (stator core 111), and a rotor shaft 122 that is connected to the rotor core 121 in a manner that rotates integrally. In the present embodiment, the rotary electric machine 1 is a rotary excitation type rotary electric machine. Therefore, a coil is wound around the stator core 111 so as to form coil ends 112 that protrude from the stator core 111 to both sides of the axial direction L (the first axial side L1 and the second axial side L2). In addition, a permanent magnet 123 is provided on the rotor core 121. In addition, in the present embodiment, the rotary electric machine 1 is an inner rotor type rotary electric machine, so the rotor core 121 is arranged on the inner side of the radial direction R than the stator core 111. In addition, the rotor shaft 122 is connected to the inner circumferential surface of the rotor core 121.

[0028] The rotor shaft 122 is a rotating member that rotates around the first axis A1. The rotor shaft 122 is formed in a cylindrical shape extending along the axial direction L. The rotor shaft 122 is supported by the rotor bearing B1 so as to be rotatable. In the present embodiment, the rotor shaft 122 is configured to protrude from the rotor core 121 to both sides of the axial direction L. Moreover, the rotor bearing B1 includes a first rotor bearing B1a that supports the portion of the rotor shaft 122 that protrudes from the rotor core 121 to the axial first side L1 so as to be rotatable, and a second rotor bearing B1b that supports the portion of the rotor shaft 122 that protrudes from the rotor core 121 to the axial second side L2 so as to be rotatable. In the illustrated example, the end of the rotor shaft 122 on the axial first side L1 is supported by the first side wall portion 22 of the housing 2 via the first rotor bearing B1a so as to be rotatable. Moreover, the end of the rotor shaft 122 on the axial second side L2 is supported by the partition portion 24 of the housing 2 via the second rotor bearing B1b so as to be rotatable.

[0029] In addition, in the present embodiment, both end surfaces of the rotor shaft 122 are open in the axial direction L. Furthermore, the internal space of the rotor shaft 122 functions as a rotor shaft oil passage 122a through which oil flows.

[0030] The input member 3 is an input component of the drive transmission mechanism 10 . The input member 3 has an input shaft 31 and an input gear 32 .

[0031] The input shaft 31 is a rotating member that rotates around the first axis A1. The input shaft 31 is formed to extend along the axial direction L. In the present embodiment, the input shaft 31 is inserted into a through hole that penetrates the partition wall portion 24 of the housing 2 along the axial direction L. Moreover, the end portion of the input shaft 31 on the axial first side L1 is connected to the end portion of the axial second side L2 of the rotor shaft 122. In the example shown in the figure, the end portion of the input shaft 31 on the axial first side L1 is inserted into the end portion of the axial second side L2 of the rotor shaft 122 in such a manner that the input shaft 31 is located on the inner side of the radial direction R of the rotor shaft 122, and the ends are connected to each other by spline engagement.

[0032] In the present embodiment, the input shaft 31 is rotatably supported relative to the housing 2 via the first input bearing B3a and the second input bearing B3b. Specifically, a portion of the input shaft 31 closer to the first axial side L1 than the center portion in the axial direction L and closer to the second axial side L2 than the connection portion with the rotor shaft 122 is rotatably supported by the partition wall portion 24 of the housing 2 via the first input bearing B3a. Furthermore, an end portion of the input shaft 31 on the second axial side L2 is rotatably supported by the second side wall portion 23 of the housing 2 via the second input bearing B3b.

[0033] In the present embodiment, the input shaft 31 is formed in a cylindrical shape with its end surface on the second axial side L2 being open. The internal space of the input shaft 31 functions as an input shaft oil passage 31a through which oil flows.

[0034] The input gear 32 is a gear that transmits the driving force from the rotating electric machine 1 to the counter gear mechanism 4. The input gear 32 is connected to the input shaft 31 so as to rotate integrally with the input shaft 31. In the present embodiment, the input gear 32 is formed integrally with the input shaft 31. In addition, in the present embodiment, the input gear 32 is arranged between the first input bearing B3a and the second input bearing B3b.

[0035] The counter gear mechanism 4 is disposed between the input member 3 and the differential gear mechanism 5 in the power transmission path P. The counter gear mechanism 4 includes a counter shaft 41 , a first counter gear 42 , and a second counter gear 43 .

[0036] The secondary shaft 41 is a rotating member that rotates around the second axis A2. The secondary shaft 41 is formed to extend along the axial direction L. In the present embodiment, the secondary shaft 41 is rotatably supported by the housing 2 via the first secondary bearing B4a and the second secondary bearing B4b. Specifically, the end of the secondary shaft 41 on the axial first side L1 is rotatably supported by the partition wall portion 24 of the housing 2 via the first secondary bearing B4a. Furthermore, the end of the secondary shaft 41 on the axial second side L2 is rotatably supported by the second side wall portion 23 of the housing 2 via the second secondary bearing B4b.

[0037] In the present embodiment, the counter shaft 41 is formed in a cylindrical shape with both end surfaces opened in the axial direction L. The internal space of the counter shaft 41 functions as a counter shaft oil passage 41 a through which oil flows.

[0038] The first reverse gear 42 is an input member of the reverse gear mechanism 4. The first reverse gear 42 meshes with the input gear 32 of the input member 3. The first reverse gear 42 is connected to the secondary shaft 41 in a manner that it rotates integrally with the secondary shaft 41. In the present embodiment, the first reverse gear 42 is connected to the secondary shaft 41 by spline engagement. In addition, in the present embodiment, the first reverse gear 42 is arranged between the first secondary bearing B4a and the second secondary bearing B4b, and is closer to the second axial side L2 than the second reverse gear 43.

[0039] The second reverse gear 43 is an output member of the reverse gear mechanism 4. In the present embodiment, the second reverse gear 43 is formed to have a smaller diameter than the first reverse gear 42. The second reverse gear 43 is connected to the countershaft 41 in such a manner that it rotates integrally with the countershaft 41. In the present embodiment, the second reverse gear 43 is formed integrally with the countershaft 41. In addition, in the present embodiment, the second reverse gear 43 is arranged between the first counterbearing B4a and the second counterbearing B4b, and is closer to the first axial side L1 than the first reverse gear 42.

[0040] The differential gear mechanism 5 distributes the driving force transmitted from the rotating electric machine 1 side to the first output member 61 and the second output member 62. The differential gear mechanism 5 includes a differential input gear 51, a differential case 52, a pinion shaft 53, a pair of pinion gears 54, a first side gear 55, and a second side gear 56. In the present embodiment, the pair of pinion gears 54, the first side gear 55, and the second side gear 56 are all bevel gears.

[0041] The differential input gear 51 is an input member of the differential gear mechanism 5. The differential input gear 51 meshes with the second counter gear 43 of the counter gear mechanism 4. The differential input gear 51 is connected to the differential case 52 in such a manner as to rotate integrally with the differential case 52. In the present embodiment, the outer peripheral edge portion of the differential input gear 51 corresponds to the largest portion in the radial direction R of the differential gear mechanism 5, that is, the "maximum diameter portion". In addition, in the present embodiment, the rotary electric machine 1 is arranged on the first axial side L1 relative to the differential input gear 51.

[0042] In the present embodiment, the differential input gear 51 is equivalent to a "lifting gear G" that lifts up the oil in the oil storage portion 2a formed inside the housing 2. The oil stored in the oil storage portion 2a is lifted up by the rotation of the differential input gear 51. Moreover, the oil lifted up by the differential input gear 51 is supplied to the gear meshing portion of the plurality of gears included in the drive transmission mechanism 10. In the present embodiment, the gear meshing portion of the plurality of gears included in the drive transmission mechanism 10 includes a meshing portion between the input gear 32 and the first reverse gear 42, a meshing portion between the second reverse gear 43 and the differential input gear 51, and a meshing portion between a pair of pinion gears 54 and the first side gear 55 and the second side gear 56.

[0043] The differential case 52 is a rotating member that rotates around the third axis A3. In the present embodiment, the differential case 52 is rotatably supported by the case 2 via the first differential bearing B5a and the second differential bearing B5b. Specifically, the end of the differential case 52 on the axial first side L1 is rotatably supported by the partition wall portion 24 of the case 2 via the first differential bearing B5a. Furthermore, the end of the differential case 52 on the axial second side L2 is rotatably supported by the second side wall portion 23 of the case 2 via the second differential bearing B5b.

[0044] The differential case 52 is a hollow member. A pinion shaft 53 , a pair of pinion gears 54 , a first side gear 55 , and a second side gear 56 are accommodated inside the differential case 52 .

[0045] The pinion shaft 53 extends along the radial direction R based on the third axis A3. The pinion shaft 53 is inserted through a pair of pinion gears 54, and supports them so as to be rotatable. The pinion shaft 53 is configured to penetrate the differential case 52. The pinion shaft 53 is locked with the differential case 52 by the locking member 53a, and rotates integrally with the differential case 52. In the example shown in the figure, the locking member 53a is a rod-shaped pin inserted through both the differential case 52 and the pinion shaft 53.

[0046] The pair of pinion gears 54 are mounted on the pinion shaft 53 in a state of being opposed to each other with a gap in the radial direction R based on the third axis A3. The pair of pinion gears 54 are configured to be rotatable (autorotational) about the pinion shaft 53 and rotatable (revolutional) about the third axis A3.

[0047] The first side gear 55 and the second side gear 56 are allocated rotating members in the differential gear mechanism 5. The first side gear 55 and the second side gear 56 are arranged to be opposite to each other with a gap in the axial direction L, sandwiching the pinion shaft 53. The first side gear 55 is arranged on the first axial side L1 of the second side gear 56. The first side gear 55 and the second side gear 56 are configured to rotate in the circumferential direction in the internal space of the differential case 52, respectively. The first side gear 55 and the second side gear 56 are meshed with a pair of pinion gears 54. The first side gear 55 is connected to the first output member 61 in a manner that rotates as a whole. On the other hand, the second side gear 56 is connected to the second output member 62 in a manner that rotates as a whole.

[0048] Each of the first output member 61 and the second output member 62 is drivingly coupled to the wheels W. Each of the first output member 61 and the second output member 62 transmits the driving force distributed by the differential gear mechanism 5 to the wheels W.

[0049] In the present embodiment, the first output member 61 includes a first axle 611 and a relay member 612. The first axle 611 is drivingly connected to the wheel W on the first axial side L1. The relay member 612 is a rotating member that rotates around the third axis A3. The relay member 612 is a shaft member extending in the axial direction L. The relay member 612 is inserted through a through hole that penetrates the partition wall portion 24 of the housing 2 in the axial direction L. The relay member 612 is supported by the first side wall portion 22 of the housing 2 via the output bearing B6 so as to be rotatable. The end of the relay member 612 on the first axial side L1 is exposed to the outside of the housing 2 through the through hole that penetrates the first side wall portion 22 of the housing 2 in the axial direction L. The end of the relay member 612 on the first axial side L1 is connected to the first axle 611 in a manner that rotates integrally. In the present embodiment, the relay member 612 is formed in a cylindrical shape with an open end surface on the first axial side L1. Furthermore, corresponding splines are formed on the inner circumferential surface of the relay component 612 and the outer circumferential surface of the end portion on the axial second side L2 of the first axle 611, and these splines are engaged with each other, thereby connecting the relay component 612 and the first axle 611 in a manner that rotates as a whole. On the other hand, the end portion on the axial second side L2 of the relay component 612 is connected to the first side gear 55 of the differential gear mechanism 5 in a manner that rotates as a whole. In the present embodiment, corresponding splines are formed on the outer circumferential surface of the end portion on the axial second side L2 of the relay component 612 and the inner circumferential surface of the first side gear 55, and these splines are engaged with each other, thereby connecting the relay component 612 and the first side gear 55 in a manner that rotates as a whole.

[0050] In the present embodiment, the second output member 62 includes a second axle 621. The second axle 621 is drivingly connected to the wheel W on the second axial side L2. The second axle 621 is connected to the second side gear 56 in a manner of integral rotation. In the present embodiment, corresponding splines are formed on the outer peripheral surface of the end portion of the second axle 621 on the first axial side L1 and the inner peripheral surface of the second side gear 56, and these splines are engaged with each other, thereby connecting the second axle 621 and the second side gear 56 in a manner of integral rotation.

[0051] like Figure 1 as well as Figure 3 As shown, the vehicle drive device 100 includes a first hydraulic pump 71 driven by a driving force transmitted in a power transmission path P, and a second hydraulic pump 72 driven by a dedicated driving force source independent of the power transmission path P. Each of the first hydraulic pump 71 and the second hydraulic pump 72 is a pump that draws oil from an oil storage portion 2a stored in the housing 2 and discharges the drawn oil.

[0052] In the present embodiment, the first hydraulic pump 71 is accommodated in the housing 2. In addition, in the present embodiment, the first hydraulic pump 71 is a so-called mechanical hydraulic pump that is driven by the rotation of a rotating member provided in the drive transmission mechanism 10. The first hydraulic pump 71 includes a pump input gear 711, a pump drive shaft 712, an inner rotor 713, an outer rotor 714, and a pump cover 715.

[0053] The pump input gear 711 is an input member of the first hydraulic pump 71. The pump input gear 711 meshes with the pump drive gear 57 connected to the differential case 52 in a manner of integral rotation. The pump drive shaft 712 is connected to the pump input gear 711 in a manner of integral rotation. In the present embodiment, the pump input gear 711 is arranged at the end of the second axial side L2 of the pump drive shaft 712. The inner rotor 713 is connected to the pump drive shaft 712 in a manner of integral rotation. In the present embodiment, the inner rotor 713 is arranged at the end of the first axial side L1 of the pump drive shaft 712. The outer rotor 714 is arranged on the outer side of the radial direction R relative to the inner rotor 713. The inner teeth formed on the inner circumferential surface of the outer rotor 714 mesh with the outer teeth formed on the outer circumferential surface of the inner rotor 713, and the outer rotor 714 rotates along with the rotation of the inner rotor 713. The pump cover 715 is arranged to cover the inner rotor 713 and the outer rotor 714. The pump cover 715 rotatably supports the pump drive shaft 712. Specifically, the pump drive shaft 712 is inserted into a through hole that penetrates the pump cover 715 in the axial direction L.

[0054] Thus, in the present embodiment, the first hydraulic pump 71 is driven by the rotation of the differential case 52 of the differential gear mechanism 5. The rotation speed of the differential case 52 is lower than the rotation speed of the rotary electric machine 1 and the rotation speed of the counter gear mechanism 4. Therefore, according to the structure in which the first hydraulic pump 71 is driven by the rotation of the differential case 52, the rotation speed of the first hydraulic pump 71 can be suppressed to be lower than the structure in which the first hydraulic pump 71 is driven by the rotary electric machine 1 or the counter gear mechanism 4. As a result, the energy loss caused by the high-speed rotation of the first hydraulic pump 71 can be suppressed to be smaller, and the energy efficiency of the vehicle drive device 100 can be improved.

[0055] In addition, in the present embodiment, the first hydraulic pump 71 is arranged at a position overlapping with the differential gear mechanism 5 when viewed in the axial direction of the axial direction L. Specifically, the inner rotor 713 and the outer rotor 714 as the pump rotors of the first hydraulic pump 71 are arranged at a position overlapping with the differential gear mechanism 5 when viewed in the axial direction. Moreover, in the present embodiment, the first hydraulic pump 71 is arranged on the side of the rotary electric machine 1 in the axial direction L (the first axial side L1) of the differential input gear 51 of the differential gear mechanism 5 and on the side of the differential gear mechanism 5 in the axial direction L (the second axial side L2) of the central part in the axial direction L of the rotary electric machine 1. Specifically, the components constituting the first hydraulic pump 71 (here, the pump input gear 711, the pump drive shaft 712, the inner rotor 713, the outer rotor 714, and the pump cover 715) are arranged in the axial direction L between the differential input gear 51 and the central part in the axial direction L of the rotary electric machine 1. Here, regarding the arrangement of two members, "overlapping when viewed from a specific direction" means that when an imaginary line parallel to the line of sight is moved in directions orthogonal to the imaginary line, there is at least a portion of the region where the imaginary line intersects both members.

[0056] like Figure 3 As shown, in the present embodiment, the second hydraulic pump 72 is an electric hydraulic pump driven by an electric motor 72a. That is, in the present embodiment, the electric motor 72a is equivalent to a driving force source independent of the power transmission path P. The electric motor 72a can use, for example, an AC rotary motor driven by multi-phase AC power. In this case, although the illustration is omitted, the electric motor 72a is connected to a DC power supply via an inverter that performs power conversion between DC power and AC power, and the drive of the electric motor 72a is controlled via the inverter.

[0057] In the present embodiment, the second hydraulic pump 72 is stopped when the temperature of the inner peripheral surface 122 d of the rotor shaft 122 is equal to or lower than a predetermined value.

[0058] like Figure 3 as well as Figure 4 As shown, the vehicle drive device 100 includes a first oil passage 91 and a second oil passage 92 that are independent of each other.

[0059] The first oil passage 91 is an oil passage for supplying the oil discharged from the first hydraulic pump 71 to the rotor bearing B1 that rotatably supports the rotor shaft 122. In the present embodiment, the first oil passage 91 includes an oil passage for supplying the oil discharged from the first hydraulic pump 71 to a plurality of bearings that rotatably supports a plurality of rotating components provided in the drive transmission mechanism 10. That is, the first oil passage 91 supplies the oil discharged from the first hydraulic pump 71 to the first rotor bearing B1a and the second rotor bearing B1b that rotatably supports the rotor shaft 122, the first input bearing B3a and the second input bearing B3b that rotatably supports the input shaft 31, the first auxiliary bearing B4a and the second auxiliary bearing B4b that rotatably supports the auxiliary shaft 41, the first differential bearing B5a and the second differential bearing B5b that rotatably supports the differential case 52, and the output bearing B6 that rotatably supports the relay member 612. In this way, the first oil passage 91 and the first hydraulic pump 71 constitute a hydraulic circuit for lubrication.

[0060] The second oil circuit 92 is an oil circuit for supplying the oil discharged from the second hydraulic pump 72 to the inner peripheral surface 122d of the rotor shaft 122. The second oil circuit 92 and the second hydraulic pump 72 constitute a hydraulic circuit for cooling the rotary electric machine 1. In this way, the second oil circuit 92 is configured to supply to the cooling target part CP of the rotary electric machine 1. In the present embodiment, the cooling target part CP includes the outer peripheral surface 111a of the stator core 111 and the coil end 112 in addition to the inner peripheral surface 122d of the rotor shaft 122. That is, in the present embodiment, the second oil circuit 92 includes an oil circuit for supplying the oil discharged from the second hydraulic pump 72 to the outer peripheral surface 111a of the stator core 111, and an oil circuit for supplying to the coil end 112.

[0061] Below, refer to Figure 3 as well as Figure 4 The flow of oil in the first oil passage 91 of this embodiment will be described. Figure 3 as well as Figure 4 The solid line and dashed arrows in FIG. 8 show the flow of oil.

[0062] like Figure 3 As shown, a portion of the oil discharged from the first hydraulic pump 71 flows along the inner surface of the peripheral wall portion 21 of the housing 2 toward the first axial side L1 and reaches the output bearing B6. In addition, another portion of the oil discharged from the first hydraulic pump 71 passes through the lubricating oil passage 22a formed in the first side wall portion 22 of the housing 2 and reaches the first rotor bearing B1a.

[0063] On the other hand, Figure 4As shown, another part of the oil discharged from the first hydraulic pump 71 flows toward the second axial side L2 and reaches the first differential bearing B5a. In addition, a part of the oil discharged from the first hydraulic pump 71 and flowing toward the second axial side L2 is supplied to each of the first lubricating oil passage 23a and the second lubricating oil passage 23b formed in the second side wall portion 23 of the housing 2. The oil supplied to the first lubricating oil passage 23a passes through the first lubricating oil passage 23a and reaches the second differential bearing B5b. On the other hand, the oil supplied to the second lubricating oil passage 23b flows into each of the first branch oil passage 23c, the second branch oil passage 23d, and the third branch oil passage 23e branched from the second lubricating oil passage 23b.

[0064] The first branch oil passage 23c is connected to the countershaft oil passage 41a via the opening on the axial second side L2 of the countershaft 41. Therefore, the oil flowing into the first branch oil passage 23c is supplied to the countershaft oil passage 41a via the first branch oil passage 23c. The oil supplied to the countershaft oil passage 41a flows toward the axial first side L1 in the countershaft oil passage 41a, and flows out to the outside of the countershaft 41 via the opening on the axial first side L1 of the countershaft 41. Then, the oil flowing out to the outside of the countershaft 41 reaches the first auxiliary bearing B4a.

[0065] On the other hand, the oil flowing into the second branch oil passage 23d passes through the second branch oil passage 23d and reaches the second auxiliary bearing B4b. In addition, part of the oil supplied to the auxiliary shaft oil passage 41a also passes through the gap between the auxiliary shaft 41 and the second side wall portion 23 and reaches the second auxiliary bearing B4b.

[0066] The third branch oil passage 23e communicates with the input shaft oil passage 31a via an opening on the second axial side L2 of the input shaft 31. Therefore, the oil flowing into the third branch oil passage 23e is supplied to the input shaft oil passage 31a through the third branch oil passage 23e.

[0067] A part of the oil supplied to the input shaft oil passage 31a flows toward the axial first side L1 in the input shaft oil passage 31a. Then, the oil reaching the end of the axial first side L1 of the input shaft oil passage 31a flows out to the outside of the input shaft 31 through the supply oil passage 31b formed in a manner penetrating the input shaft 31 in the radial direction R. Here, the supply oil passage 31b is formed so as to communicate the space surrounded by the second rotor bearing B1b, the first input bearing B3a, the housing 2, and the input shaft 31 with the input shaft oil passage 31a. Therefore, the oil flowing out to the outside of the input shaft 31 reaches each of the second rotor bearing B1b and the first input bearing B3a.

[0068] On the other hand, the remaining portion of the oil supplied to the input shaft oil passage 31 a passes through the gap between the input shaft 31 and the second side wall portion 23 and reaches the second input bearing B3 b .

[0069] As described above, in the present embodiment, the first oil passage 91 includes the lubricating oil passage 22a, the first lubricating oil passage 23a, the second lubricating oil passage 23b, the first branch oil passage 23c, the second branch oil passage 23d, the third branch oil passage 23e, the countershaft oil passage 41a, the input shaft oil passage 31a, and the supply oil passage 31b. The lubricating oil passage 22a corresponds to "the oil passage formed in the first side wall portion 22". The first lubricating oil passage 23a, the second lubricating oil passage 23b, the first branch oil passage 23c, the second branch oil passage 23d, and the third branch oil passage 23e correspond to "the oil passage formed in the second side wall portion 23". In addition, the first lubricating oil passage 23a, the second branch oil passage 23d, the input shaft oil passage 31a, the supply oil passage 31b, and the countershaft oil passage 41a correspond to "the oil passage for supplying the oil discharged from the first hydraulic pump 71 to the plurality of bearings that rotatably support the plurality of rotating parts provided in the drive transmission mechanism 10".

[0070] Below, refer to Figure 3 The flow of oil in the second oil passage 92 according to the present embodiment will be described.

[0071] like Figure 3 As shown, the oil discharged from the second hydraulic pump 72 is cooled by the oil cooler 73. The oil cooler 73, for example, includes a pipe through which the oil flows, and is configured to perform heat exchange between a refrigerant (for example, cooling water, air, etc.) flowing outside the pipe and the oil in the pipe, thereby cooling the oil. Thus, in this embodiment, the oil cooler 73 for cooling the oil is provided in the second oil circuit 92. On the other hand, the oil cooler for cooling the oil is not provided in the first oil circuit 91.

[0072] The oil cooled by the oil cooler 73 is supplied to the cooling oil passage 22b formed in the first side wall portion 22 of the housing 2. The oil supplied to the cooling oil passage 22b flows into each of the first connecting oil passage 22c connected to the inner supply oil passage 81a and the second connecting oil passage 22d connected to the outer supply oil passage 82a.

[0073] The oil flowing into the first connecting oil passage 22c is supplied to the inner supply oil passage 81a through the first connecting oil passage 22c. The inner supply oil passage 81a is an oil passage formed in the inner supply member 81. The inner supply member 81 is arranged on the inner side of the radial direction R of the rotating electric machine 1. Specifically, the inner supply member 81 is arranged on the inner side of the radial direction R of the rotor shaft 122. That is, the inner supply member 81 is arranged inside the rotor shaft oil passage 122a. The inner supply member 81 is formed to extend in the axial direction L. The inner supply member 81 is formed in a cylindrical shape with an end face opened on the first axial side L1. Moreover, the internal space of the inner supply member 81 functions as the inner supply oil passage 81a. The end of the inner supply member 81 on the first axial side L1 is fixed to the first side wall portion 22 of the housing 2 so that the inner supply oil passage 81a is connected to the first connecting oil passage 22c.

[0074] The oil supplied to the inner supply oil passage 81a flows in the inner supply oil passage 81a toward the second axial side L2. The oil in the inner supply oil passage 81a flows out to the outside of the inner supply member 81 through the supply hole 81b formed so as to penetrate the inner supply member 81 in the radial direction R. A plurality of supply holes 81b are arranged at intervals in the circumferential direction of the inner supply member 81 so as to connect the inner supply oil passage 81a with the rotor shaft oil passage 122a.

[0075] The oil flowing out of the inner supply member 81 is supplied to the rotor shaft oil passage 122a. In other words, the oil flowing out of the inner supply member 81 is supplied to the inner circumferential surface 122d of the rotor shaft 122 forming the rotor shaft oil passage 122a. The oil supplied to the inner circumferential surface 122d of the rotor shaft 122 exchanges heat with the permanent magnet 123 via the rotor shaft 122 and the rotor core 121, thereby cooling the permanent magnet 123. In this way, the cooling target portion CP of the rotary electric machine 1 to which the oil discharged from the second hydraulic pump 72 is supplied includes the inner circumferential surface 122d of the rotor shaft 122.

[0076] A portion of the oil supplied to the rotor shaft oil passage 122a flows into each of the first supply oil passage 122b and the second supply oil passage 122c formed in a manner penetrating the rotor shaft 122 in the radial direction R. Here, the first supply oil passage 122b is formed at a position overlapping with the coil end 112 on the first axial side L1 when viewed in the radial direction of the radial direction R of the rotor shaft 122. In addition, the second supply oil passage 122c is formed at a position overlapping with the coil end 112 on the second axial side L2 when viewed in the radial direction of the radial direction R of the rotor shaft 122. Therefore, as the rotor shaft 122 rotates, oil is ejected from each of the first supply oil passage 122b and the second supply oil passage 122c toward the corresponding coil end 112. And the coil end 112 is cooled by the oil adhering to the coil end 112. In this way, the cooling target portion CP of the rotary electric machine 1 to which the oil discharged from the second hydraulic pump 72 is supplied includes the coil end 112.

[0077] On the other hand, the oil flowing into the second connecting oil passage 22d is supplied to the outer supply oil passage 82a through the second connecting oil passage 22d. The outer supply oil passage 82a is an oil passage formed in the outer supply member 82. The outer supply member 82 is arranged on the upper side in the vertical direction relative to the rotating electric machine 1. Specifically, the outer supply member 82 is arranged on the upper side in the vertical direction than the portion of the coil end 112 and the stator core 111 that overlaps with the outer supply member 82 when viewed in the vertical direction. The outer supply member 82 is formed to extend in the axial direction L. The outer supply member 82 is formed in a cylindrical shape with an open end face on the first axial side L1. Moreover, the internal space of the outer supply member 82 functions as the outer supply oil passage 82a. The end of the outer supply member 82 on the first axial side L1 is supported by the first side wall portion 22 of the housing 2 so that the outer supply oil passage 82a is connected to the second connecting oil passage 22d. On the other hand, the end of the outer supply member 82 on the second axial side L2 is supported by the partition wall portion 24 of the housing 2.

[0078] The oil supplied to the outer supply oil passage 82a flows toward the axial second side L2 in the outer supply oil passage 82a. The oil in the outer supply oil passage 82a falls through the first supply hole 82b and the second supply hole 82c formed in the radial direction R through the outer supply member 82.

[0079] The first supply holes 82b are arranged at a plurality of positions (two positions in the illustrated example) in the axial direction L so as to overlap the coil end 112 on the first axial side L1 and the coil end 112 on the second axial side L2 when viewed from the vertical direction, and a plurality of the first supply holes 82b are arranged at intervals along the circumferential direction of the outer supply member 82. Therefore, a portion of the oil in the outer supply oil passage 82a drips toward the coil end 112 through the first supply holes 82b. In addition, the coil end 112 is cooled by the oil adhering to the coil end 112.

[0080] In addition, the second supply hole 82c is arranged at a position overlapping with the stator core 111 when viewed from the vertical direction. In the example shown in the figure, the second supply hole 82c is arranged at multiple positions (two positions in the example shown in the figure) in the axial direction L, and multiple supply holes 82c are arranged at intervals along the circumferential direction of the outer supply member 82. Therefore, a part of the oil in the outer supply oil path 82a drips onto the outer peripheral surface 111a of the stator core 111 through the second supply hole 82c. The oil dripping onto the outer peripheral surface 111a of the stator core 111 exchanges heat with the coil wound on the stator core 111 through the stator core 111, thereby cooling the coil. In this way, the cooling target part CP of the rotating electric machine 1 to which the oil discharged from the second hydraulic pump 72 is supplied includes the outer peripheral surface 111a of the stator core 111.

[0081] As described above, in the present embodiment, the second oil passage 92 includes the cooling oil passage 22b, the first connecting oil passage 22c, the second connecting oil passage 22d, the inner supply oil passage 81a, the supply hole 81b, the rotor shaft oil passage 122a, the first supply oil passage 122b, the second supply oil passage 122c, the outer supply oil passage 82a, the first supply hole 82b, and the second supply hole 82c. The outer supply oil passage 82a, the first supply hole 82b, and the second supply hole 82c correspond to "the oil passage for supplying the oil discharged from the second hydraulic pump 72 to the outer peripheral surface 111a of the stator core 111".

[0082] As described above, the first oil circuit 91 and the second oil circuit 92 are independently provided outside the oil storage section 2a. In other words, the first oil circuit 91 and the second oil circuit 92 are not connected to each other outside the oil storage section 2a and are separated. Therefore, in the vehicle drive device 100, the hydraulic circuit for lubrication and the hydraulic circuit for cooling are independent of each other. Thus, when it is not necessary to supply oil to any one of the cooling target part CP of the rotating electrical machine 1 and the plurality of bearings B1a, B1b, B3a, B3b, B4a, B4b, B5a, B5b, and B6, it is possible to avoid supplying oil to both of them. For example, when a vehicle equipped with the vehicle drive device 100 is traveling at a high speed, when the rotating electrical machine 1 is under a low load, the supply of oil from the second hydraulic pump 72 to the cooling target part CP can be stopped. As a result, the energy loss caused by the unnecessary driving of the second hydraulic pump 72 can be suppressed to a small extent, and the energy efficiency of the vehicle drive device 100 can be improved.

[0083] However, the electric motor 72a that generally drives the second hydraulic pump 72 is a small rotary motor compared to the rotary motor 1 for driving the wheel W, and the maximum value of the torque that can be output is smaller than the rotary motor 1. Therefore, in a low-temperature environment with high viscosity of oil, there is a possibility that the second hydraulic pump 72 cannot properly draw oil after the vehicle equipped with the vehicle drive device 100 starts to travel. In particular, in order to improve the energy efficiency of the vehicle drive device 100, such a problem is likely to occur when a small motor is used as the electric motor 72a for the second hydraulic pump 72. However, usually in a low-temperature environment with high viscosity of oil, the temperature of the cooling target part CP of the rotary motor 1 is also low, and the necessity of cooling the cooling target part CP is low. Therefore, even with a structure such as the present embodiment, there is almost no influence caused by the inability of the second hydraulic pump 72 to properly draw oil.

[0084] [Other implementation methods]

[0085] (1) In the above embodiment, the structure in which oil is supplied to all of the plurality of bearings that rotatably support the plurality of rotating components provided in the drive transmission mechanism 10 through the first oil passage 91 is described as an example. However, the present invention is not limited to such a structure, and the structure in which oil is not supplied to a part or all of the plurality of bearings that rotatably support the plurality of rotating components provided in the drive transmission mechanism 10 through the first oil passage 91 may also be used.

[0086] (2) In the above embodiment, the structure in which the first oil circuit 91 includes the oil circuit (lubricating oil circuit 22a) formed in the first side wall portion 22 and the oil circuit (first lubricating oil circuit 23a, second lubricating oil circuit 23b, first branch oil circuit 23c, second branch oil circuit 23d, third branch oil circuit 23e) formed in the second side wall portion 23 is described as an example. However, the present invention is not limited to such a structure, and the first oil circuit 91 may include only one of the oil circuit formed in the first side wall portion 22 and the oil circuit formed in the second side wall portion 23. Alternatively, the first oil circuit 91 may not include either the oil circuit formed in the first side wall portion 22 or the oil circuit formed in the second side wall portion 23.

[0087] (3) In the above embodiment, the structure in which the cooling target portion CP includes the coil end portion 112, the outer peripheral surface 111a of the stator core 111, and the inner peripheral surface 122d of the rotor shaft 122 is described as an example. However, the present invention is not limited to such a structure, and the cooling target portion CP may be configured not to include one or both of the coil end portion 112 and the outer peripheral surface 111a of the stator core 111. In addition, the cooling target portion CP may include, for example, a surface of an oil path formed inside the rotor core 121 so as to pass through the vicinity of the permanent magnet 123.

[0088] (4) In the above embodiment, the rotor bearing B1 includes, as an example, a first rotor bearing B1a that rotatably supports a portion of the rotor shaft 122 protruding from the rotor core 121 to the first axial side L1, and a second rotor bearing B1b that rotatably supports a portion of the rotor shaft 122 protruding from the rotor core 121 to the second axial side L2. However, the present invention is not limited to such a structure, and for example, at least one of the first rotor bearing B1a and the second rotor bearing B1b may support, from the inner side in the radial direction R, a portion of the rotor shaft 122 that overlaps with the rotor core 121 when viewed radially along the radial direction R. In addition, the rotor bearing B1 may be composed of only one bearing, or may include three or more bearings.

[0089] (5) In the above embodiment, the structure in which the oil in the oil reservoir 2a lifted up by the differential input gear 51 as the lifting gear G is supplied to the gear meshing parts of the plurality of gears included in the drive transmission mechanism 10 is described as an example. However, instead of or in addition to this structure, a structure in which the oil in the first oil passage 91 is supplied to the gear meshing parts may be used. In addition, the lifting gear G may be a gear other than the differential input gear 51.

[0090] (6) In the above embodiment, the first hydraulic pump 71 is driven by the rotation of the differential case 52. However, the present invention is not limited to such a structure. For example, the first hydraulic pump 71 may be driven by the rotation of the input shaft 31 or the rotation of the countershaft 41.

[0091] (7) In the above embodiment, the differential input gear 51 is described as an example of the largest diameter portion of the differential gear mechanism 5. However, the present invention is not limited to such a structure, and for example, a part of the differential case 52 may be the largest diameter portion of the differential gear mechanism 5.

[0092] (8) In the above embodiment, the structure in which the first hydraulic pump 71 is arranged at a position overlapping with the differential gear mechanism 5 when viewed in the axial direction along the axial direction L is described as an example. However, the present invention is not limited to such a structure, and the first hydraulic pump 71 may be arranged at a position not overlapping with the differential gear mechanism 5 when viewed in the axial direction. In this case, the structure in which the first hydraulic pump 71 is arranged at a position overlapping with the differential gear mechanism 5 when viewed in the radial direction along the radial direction R of the differential gear mechanism 5 may also be used.

[0093] (9) In the above embodiment, the first hydraulic pump 71 is described as an example of a configuration in which the first hydraulic pump 71 is disposed on the side of the rotary electric machine 1 in the axial direction L (the first axial direction side L1) relative to the differential input gear 51 of the differential gear mechanism 5, and is disposed on the side of the differential gear mechanism 5 in the axial direction L (the second axial direction side L2) relative to the center portion in the axial direction L of the rotary electric machine 1. However, the configuration is not limited thereto, and for example, the first hydraulic pump 71 may be disposed on the second axial direction side L2 relative to the differential input gear 51, or may be disposed on the first axial direction side L1 relative to the center portion in the axial direction L of the rotary electric machine 1.

[0094] (10) In the above embodiment, a structure in which the second hydraulic pump 72 is stopped when the temperature of the inner circumferential surface 122d of the rotor shaft 122 is below a specified value is described as an example. However, the present invention is not limited to such a structure, and for example, a structure in which the second hydraulic pump 72 is stopped when the temperature of the cooling target part CP of the rotary electric machine 1 is below a specified value may be used. Here, "the temperature of the cooling target part CP" refers to an average value, a maximum value, etc. when the cooling target part CP includes a plurality of parts. In addition, the second hydraulic pump 72 may be always driven. In this case, for example, if the temperature of the cooling target part CP of the rotary electric machine 1 is below a specified value, control may be performed in a manner that reduces the discharge amount of oil from the second hydraulic pump 72.

[0095] (11) In the above embodiment, the oil cooler 73 is provided in the second oil passage 92, and the oil cooler for cooling oil is not provided in the first oil passage 91. However, the present invention is not limited to such a structure, and for example, the oil cooler for cooling oil may be provided in the first oil passage 91. In addition, since the second oil passage 92 is an oil passage for cooling the cooling target part CP of the rotary electric machine 1, it is preferable to provide the oil cooler 73 at least in the second oil passage 92.

[0096] (12) In the above embodiment, the rotating electrical machine 1 and the input member 3 are arranged on the first axis A1, the counter gear mechanism 4 is arranged on the second axis A2, and the differential gear mechanism 5, the first output member 61, and the second output member 62 are arranged on the third axis A3. However, the present invention is not limited to such a structure, and a structure in which part or all of the above are arranged on a common axis may be adopted. For example, the rotating electrical machine 1, the input member 3, the counter gear mechanism 4, the differential gear mechanism 5, and the first output member 61 and the second output member 62 may be arranged on the same axis.

[0097] (13) In addition, the structures disclosed in the above-mentioned embodiments can be combined with the structures disclosed in other embodiments for application as long as no contradiction occurs. With regard to other structures, the embodiments disclosed in this specification are merely examples in all aspects. Therefore, various changes can be appropriately made without departing from the scope of the purpose of the present invention.

[0098] [Overview of the above-mentioned embodiment]

[0099] Hereinafter, the outline of the vehicle drive device (100) described above will be described.

[0100] A vehicle driving device (100) comprises:

[0101] A rotating electric machine (1) which serves as a driving force source for a wheel (W), comprising a stator core (111), a rotor core (121) supported to be rotatable relative to the stator core (111), and a cylindrical rotor shaft (122) connected to the rotor core (121) in a manner that allows it to rotate integrally with the rotor core;

[0102] A drive transmission mechanism (10) provided in a power transmission path (P) connecting the rotor shaft (122) and the wheel (W);

[0103] a first hydraulic pump (71) driven by the driving force transmitted in the power transmission path (P);

[0104] a second hydraulic pump (72) driven by a driving force source (72a) independent of the power transmission path (P);

[0105] a first oil passage (91) for supplying oil discharged from the first hydraulic pump (71) to a rotor bearing (B1) for rotatably supporting the rotor shaft (122); and

[0106] The second oil passage (92) supplies the oil discharged from the second hydraulic pump (72) to the inner peripheral surface (122d) of the rotor shaft (122).

[0107] According to this structure, a first oil circuit (91) and a first hydraulic pump (71) are provided as a hydraulic circuit for lubricating a rotor bearing (B1) that rotatably supports a rotor shaft (122) of a rotating electric machine (1), and a second oil circuit (92) and a second hydraulic pump (72) are provided as a hydraulic circuit for cooling an inner peripheral surface (122d) of the rotor shaft (122). Thus, the lubrication of the rotor bearing (B1) and the cooling of the inner peripheral surface (122d) of the rotor shaft (122) can be performed independently. Therefore, when the vehicle is stopped and lubrication of the rotor bearing (B1) is not required, the supply of oil from the first hydraulic pump (71) to the rotor bearing (B1) can be stopped, and when the temperature of the rotating electric machine (1) is low and cooling of the inner peripheral surface (122d) of the rotor shaft (122) is not required, the supply of oil from the second hydraulic pump (72) to the inner peripheral surface (122d) of the rotor shaft (122) can be stopped. That is, when it is not necessary to supply oil to either the inner peripheral surface (122d) of the rotor shaft (122) or the rotor bearing (B1), it is possible to avoid supplying oil to both of them. As a result, energy loss caused by driving an unnecessary hydraulic pump can be suppressed to a minimum, and the energy efficiency of the vehicle drive device (100) can be improved.

[0108] Here, it is preferred that the first oil circuit (91) includes oil circuits (31a, 31b, 41a, 23a, 23d) for supplying oil discharged from the first hydraulic pump (71) to a plurality of bearings (B3a, B3b, B4a, B4b, B5a, B5b, B6) that support a plurality of rotating parts (31, 41, 52, 612) of the drive transmission mechanism (10) so as to be rotatable.

[0109] According to this structure, oil can be supplied to a plurality of bearings (B3a, B3b, B4a, B4b, B5a, B5b, B6) that support a plurality of rotating parts (31, 41, 52, 612) that rotate during the travel of the vehicle so as to be rotatable. That is, when lubrication of the plurality of bearings (B3a, B3b, B4a, B4b, B5a, B5b, B6) is required, they can be lubricated appropriately. On the other hand, when the lubrication of the plurality of bearings (B3a, B3b, B4a, B4b, B5a, B5b, B6) is not required, the supply of oil to them can be stopped, etc. Therefore, the energy loss caused by the driving of the unnecessary hydraulic pump can be suppressed to a smaller extent.

[0110] In addition, it is preferred that the device further comprises a housing (2) for accommodating the rotating electrical machine (1) and the drive transmission mechanism (10).

[0111] The housing (2) includes: a cylindrical peripheral wall portion (21) formed to surround the rotating electrical machine (1) and the drive transmission mechanism (10) in a radial direction (R) on the outside, a first side wall portion (22) arranged to close an opening on one side of the peripheral wall portion (21) in an axial direction (L), and a second side wall portion (23) arranged to close an opening on the other side of the peripheral wall portion (21) in the axial direction (L).

[0112] The first oil passage (91) includes an oil passage (22a) formed in the first side wall portion (22), and oil passages (23a, 23b, 23c, 23d, 23e) formed in the second side wall portion (23).

[0113] According to this structure, even if the lubricated objects including the rotor bearing (B1) are arranged in the axial (L) both side regions inside the housing (2), oil can be easily supplied from the first oil passage (91) to the lubricated objects.

[0114] Furthermore, the second oil passage (92) preferably includes oil passages (82a, 82b, 82c) for supplying oil discharged from the second hydraulic pump (72) to the outer peripheral surface (111a) of the stator core (111).

[0115] According to this structure, oil is supplied from the second oil passage (92) to the outer peripheral surface (111a) of the stator core (111) in addition to the inner peripheral surface (122d) of the rotor shaft (122). That is, the rotating electrical machine (1) is cooled from both the inner side and the outer side in the radial direction (R). Therefore, when the rotating electrical machine (1) needs to be cooled, the rotating electrical machine (1) can be cooled efficiently.

[0116] In addition, the rotor shaft (122) is preferably configured to protrude from the rotor core (121) to both sides in the axial direction (L).

[0117] The rotor bearing (B1) includes: a first rotor bearing (B1a) that rotatably supports a portion of the rotor shaft (122) that protrudes from the rotor core (121) to one side (L1) in the axial direction (L); and a second rotor bearing (B1b) that rotatably supports a portion of the rotor shaft (122) that protrudes from the rotor core (121) to the other side (L2) in the axial direction (L).

[0118] According to this structure, the rotor shaft (122) is rotatably supported by the first rotor bearing (B1a) and the second rotor bearing (B1b) at two positions that are relatively far apart in the axial direction (L). Furthermore, during the running of the vehicle, oil is supplied from the first oil passage (91) to both the first rotor bearing (B1a) and the second rotor bearing (B1b). Thus, according to this structure, the rotor shaft (122) can be appropriately supported by the first rotor bearing (B1a) and the second rotor bearing (B1b), and both can be appropriately lubricated as needed.

[0119] In addition, it is preferred that the housing (2) further comprises an oil storage portion (2a) in which oil is stored, and the housing (2) houses the rotating electrical machine (1) and the drive transmission mechanism (10).

[0120] To the gear meshing portion of the plurality of gears (32, 42, 43, 51, 54, 55, 56) included in the drive transmission mechanism (10), at least one of the oil in the first oil passage (91) and the oil in the oil reservoir (2a) lifted up by the lifting gear (G) included in the plurality of gears (32, 42, 43, 51, 54, 55, 56) is supplied.

[0121] According to this structure, while the vehicle is running, oil is supplied to the gear meshing parts of the plurality of gears (32, 42, 43, 51, 54, 55, 56) provided in the drive transmission mechanism (10) by at least one of the first oil passage (91) through which the oil discharged from the first hydraulic pump (71) flows and the lifting gear (G) that lifts up the oil stored in the oil storage part (2a). Therefore, when the gear meshing parts need to be lubricated, the gear meshing parts can be properly lubricated. On the other hand, when the gear meshing parts do not need to be lubricated, such as when the vehicle is stopped, the supply of oil to the gear meshing parts can be stopped. Therefore, the energy loss caused by supplying unnecessary oil to the gear meshing parts can be suppressed to a small extent.

[0122] In addition, the drive transmission mechanism (10) preferably includes a pair of output members (61, 62) drivingly connected to the wheels (W), and a differential gear mechanism (5) for distributing the driving force transmitted from the rotating electric machine (1) to the pair of output members (61, 62).

[0123] The differential gear mechanism (5) comprises a hollow differential case (52).

[0124] The first hydraulic pump (71) is driven by the rotation of the differential case (52).

[0125] According to this structure, the differential case (52) always rotates during the rotation of the wheel (W), that is, during the driving of the vehicle. Therefore, during the driving of the vehicle, the first hydraulic pump (71) is always in a driven state. As a result, during the driving of the vehicle, oil can be supplied from the first oil passage (91) to the rotor bearing (B1), and the rotor bearing (B1) can be properly lubricated. Therefore, it is possible to avoid insufficient lubrication of the rotor bearing (B1) during the driving of the vehicle.

[0126] In addition, the drive transmission mechanism (10) preferably includes a pair of output members (61, 62) drivingly connected to the wheels (W), and a differential gear mechanism (5) for distributing the driving force transmitted from the rotating electric machine (1) to the pair of output members (61, 62).

[0127] Based on the axial direction (L) and radial direction (R) of the output components (61, 62),

[0128] The rotating electrical machine (1) is arranged at one side (L1) in the axial direction (L) with respect to the differential gear mechanism (5), wherein the portion having the largest radial dimension (R), namely, the maximum diameter portion (51) is arranged at one side (L1) in the axial direction (L).

[0129] The first hydraulic pump (71) is arranged to overlap with the differential gear mechanism (5) when viewed along the axial direction of the axial direction (L), and is arranged on the side of the rotating electric machine (1) in the axial direction (L) closer to the maximum diameter portion (51) of the differential gear mechanism (5), and on the side of the differential gear mechanism (5) in the axial direction (L) closer to the central portion of the rotating electric machine (1) in the axial direction (L).

[0130] According to this structure, the first hydraulic pump (71) can be arranged using the space overlapping with the differential gear mechanism (5) when viewed from the axial direction, thereby suppressing the radial (R) enlargement of the vehicle drive device (100) caused by the arrangement of the first hydraulic pump (71).

[0131] In addition, according to this structure, the first hydraulic pump (71) is arranged on the side of the rotating electric machine (1) closer to the axial direction (L) than the maximum diameter portion (51) of the differential gear mechanism (5), and on the side of the differential gear mechanism (5) closer to the axial direction (L) than the central portion of the axial direction (L) of the rotating electric machine (1). That is, the first hydraulic pump (71) is arranged in the central area of ​​the vehicle drive device (100) between the rotating electric machine (1) and the maximum diameter portion (51) of the differential gear mechanism (5) which are arranged staggered in the axial direction (L). As a result, the axial (L) extension distance of the first oil passage (91) for supplying oil to the rotor bearing (B1) can be suppressed to a small value. Therefore, it is possible to set a structure in which the first oil passage (91) can easily and appropriately supply oil to the rotor bearing (B1).

[0132] Furthermore, it is preferred that the second hydraulic pump (72) be stopped when the temperature of the inner peripheral surface (122d) of the rotor shaft (122) is equal to or lower than a predetermined value.

[0133] According to this structure, when the inner peripheral surface (122d) of the rotor shaft (122) does not need to be cooled, the second hydraulic pump (72) can be stopped appropriately. Thus, the energy loss caused by the unnecessary driving of the second hydraulic pump (72) can be suppressed to a small level, and the energy efficiency of the vehicle drive device (100) can be improved.

[0134] Furthermore, it is preferred that an oil cooler (73) for cooling oil is provided in the second oil passage (92), and the oil cooler (73) is not provided in the first oil passage (91).

[0135] According to this structure, the oil supplied from the second oil passage (92) to the cooling target part (CP) of the rotating electrical machine (1) can be appropriately cooled by the oil cooler (73). Therefore, the cooling target part (CP) of the rotating electrical machine (1) can be effectively cooled.

[0136] On the other hand, the oil supplied for lubricating the rotor bearing (B1) has a lower requirement for low temperature than the oil supplied to the inner peripheral surface (122d) of the rotor shaft (122). Therefore, according to the present structure, the first oil circuit (91) for supplying oil to the plurality of bearings (B1a, B1b, B3a, B3b, B4a, B4b, B5a, B5b, B6) is not provided with an oil cooler (73), thereby reducing the pressure loss of the oil flowing in the first oil circuit (91). As a result, the energy required for driving the first hydraulic pump (71) can be suppressed to a small level, so that the energy efficiency of the vehicle drive device (100) can be improved.

[0137] Possibility of industrial application

[0138] The technology of the present invention can be used in a vehicle drive device that includes a rotating electric machine that serves as a driving force source for wheels, a drive transmission mechanism arranged in a power transmission path connecting the rotating electric machine and the wheels, a first hydraulic pump driven by the driving force transmitted in the power transmission path, and a second hydraulic pump driven by a dedicated driving force source independent of the power transmission path.

[0139] Description of Reference Numerals

[0140] 100: vehicle drive device, 1: rotating electrical machine, 122: rotor shaft, 10: drive transmission mechanism, 61: first output component, 62: second output component, 71: first hydraulic pump, 72: second hydraulic pump, 91: first oil circuit, 92: second oil circuit, B1: rotor bearing, P: power transmission path, W: wheel, L: axial direction, R: radial direction.

Claims

1. A vehicle drive device, comprising: A rotating electric machine, which is a driving force source for wheels, and includes a stator core, a rotor core rotatably supported relative to the stator core, and a cylindrical rotor shaft connected to the rotor core so as to rotate integrally therewith; a drive transmission mechanism provided in a power transmission path connecting the rotor shaft and the wheel; a first hydraulic pump driven by the driving force transmitted in the power transmission path; a second hydraulic pump driven by a driving force source independent of the power transmission path; a first oil passage that supplies oil discharged from the first hydraulic pump to a rotor bearing that rotatably supports the rotor shaft; and a second oil passage for supplying oil discharged from the second hydraulic pump to the inner peripheral surface of the rotor shaft; The second oil passage includes an oil passage that supplies oil discharged from the second hydraulic pump to the outer peripheral surface of the stator core.

2. The vehicle drive device according to claim 1, wherein: The first oil passage includes an oil passage for supplying oil discharged from the first hydraulic pump to a plurality of bearings that rotatably support a plurality of rotating members included in the drive transmission mechanism.

3. The vehicle drive device according to claim 1 or 2, wherein: It also includes a housing for accommodating the rotating motor and the drive transmission mechanism. The housing includes: a cylindrical peripheral wall portion formed to surround the rotating electrical machine and the drive transmission mechanism in a radial direction on the outside, a first side wall portion arranged to close an opening on one side of the peripheral wall portion in an axial direction, and a second side wall portion arranged to close an opening on the other side of the peripheral wall portion in the axial direction. The first oil passage includes an oil passage formed in the first side wall portion and an oil passage formed in the second side wall portion.

4. The vehicle drive device according to any one of claims 1 to 3, wherein: The rotor shaft is configured to protrude from the rotor core to both sides in the axial direction. The rotor bearing includes a first rotor bearing rotatably supporting a portion of the rotor shaft protruding from the rotor core to one side in the axial direction, and a second rotor bearing rotatably supporting a portion of the rotor shaft protruding from the rotor core to the other side in the axial direction.

5. The vehicle drive device according to any one of claims 1 to 4, wherein: The invention also includes a housing having an oil storage portion for storing oil therein and accommodating the rotating electric machine and the drive transmission mechanism. At least one of the oil in the first oil passage and the oil in the oil reservoir lifted up by a lifting gear included in the plurality of gears is supplied to the gear meshing portion of the plurality of gears included in the drive transmission mechanism.

6. The vehicle drive device according to any one of claims 1 to 5, wherein: The drive transmission mechanism includes a pair of output members drivingly connected to the wheels, and a differential gear mechanism for distributing the driving force transmitted from the rotating electric machine to the pair of output members. The differential gear mechanism includes a hollow differential case. The first hydraulic pump is driven by the rotation of the differential case.

7. The vehicle drive device according to any one of claims 1 to 6, wherein: The drive transmission mechanism includes a pair of output members drivingly connected to the wheels, and a differential gear mechanism for distributing the driving force transmitted from the rotating electric machine to the pair of output members. Taking the axial and radial directions of the output component as the reference, The rotating electrical machine is arranged on one side in the axial direction with respect to the differential gear mechanism, wherein the portion with the largest radial dimension, that is, the maximum diameter portion, is arranged on one side in the axial direction. The first hydraulic pump is configured to overlap with the differential gear mechanism when viewed in the axial direction, and is configured on the rotating electric machine side in the axial direction relative to the maximum diameter portion of the differential gear mechanism, and on the differential gear mechanism side in the axial direction relative to the axial center portion of the rotating electric machine.

8. The vehicle drive device according to any one of claims 1 to 7, wherein: When the temperature of the inner peripheral surface of the rotor shaft is equal to or lower than a predetermined value, the second hydraulic pump is stopped.

9. The vehicle drive device according to any one of claims 1 to 8, wherein: An oil cooler for cooling oil is provided in the second oil passage, but the oil cooler is not provided in the first oil passage.

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