Vehicle drive device

Abstract

According to the present invention, a case (9) comprises a first accommodation chamber (C1) in which at least a portion of a rotary electric machine is accommodated, and a second accommodation chamber (C2) that is disposed on a second side (L2) in the axial direction with respect to the first accommodation chamber and in which a power transmission mechanism is accommodated. An intake port (61) of an oil pump is disposed in the second accommodation chamber (C2), and a communication passage (95), which allows communication between the first accommodation chamber (C1) and the second accommodation chamber (C2), is positioned above a lowermost section (B1) of an end on the second side (L2) in the axial direction of the first accommodation chamber (C1), and above a lowermost section (B2) of an end on a first side (L1) in the axial direction of the second accommodation chamber (C2), while the rotor axis (X) is horizontal. In the first accommodation chamber (C1), an oil feeding structure is provided that feeds oil (F) to the communication passage (95) by using the flow, which is generated by the rotation of the rotor, of the oil (F) inside the first accommodation chamber (C1).

Description

Vehicle drive unit

[0001] The present invention relates to a vehicle drive device that includes a rotating electric machine with a rotor, an output member that is drivingly connected to a wheel, a power transmission mechanism that transmits power between the rotor and the output member, a case that houses the rotating electric machine and the power transmission mechanism, and an oil pump that draws oil from the case through an intake port and discharges it.

[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, reference numerals in Patent Document 1 will be cited in parentheses.

[0003] In the vehicle drive device (1) of Patent Document 1, the case has a first storage chamber (4R) that houses a rotating electric machine (4) and a second storage chamber (5M) adjacent to the first storage chamber that houses a power transmission mechanism (5, 6).

[0004] The second storage chamber (5M) is provided with an intake port (5o2) for drawing in oil. The oil pump (10) draws oil stored in the second storage chamber (5M) through the intake port (5o2) and sends it to the catch tank (9). The oil stored in the catch tank (9) is supplied to the rotating electric machine (4) through the first oil passage (8d) and then stored in the first storage chamber (4R), and is also supplied to the power transmission mechanism (5, 6) through the second oil passages (8b, 8c) and then stored in the second storage chamber (5M).

[0005] In the vehicle drive device (1) of Patent Document 1, when the oil level in the case tilts upward from the second storage chamber (5M) toward the first storage chamber (4R), such as when the vehicle equipped with the vehicle drive device (1) is turning, the oil stored in the catch tank (9) is configured to flow preferentially to the second oil passages (8b, 8c) so that oil is preferentially supplied to the second storage chamber (5M) where the intake port (5o2) is located. In this way, even when the oil level in the case tilts as described above, a sufficient amount of oil is ensured in the second storage chamber (5M) where the intake port (5o2) is located.

[0006] Japanese Patent Application Laid-Open No. 2021-148140

[0007] However, the vehicle drive device (1) of Patent Document 1 requires the provision of a catch tank (9), which increases the number of parts.

[0008] Therefore, it is desirable to realize a vehicle drive device that can keep the number of parts to a minimum and ensure a sufficient amount of oil in the second storage chamber where the intake port is located, even when the oil level in the case slopes upward as it moves from the second storage chamber to the first storage chamber.

[0009] In view of the above, a characteristic configuration of a vehicle drive device is a vehicle drive device including: a rotating electric machine having a rotor; an output member drivingly connected to a wheel; a power transmission mechanism for transmitting power between the rotor and the output member; a case accommodating the rotating electric machine and the power transmission mechanism; and an oil pump for drawing in oil from the case through an intake port and discharging it, wherein an axial direction is defined as a direction along a rotor axis that is the rotational axis of the rotor, one side in the axial direction is defined as a first axial side, and the other side in the axial direction is defined as a second axial side, the case including a first housing chamber accommodating at least a part of the rotating electric machine, and a second housing chamber arranged on the second axial side of the first housing chamber and accommodating the power transmission mechanism, the intake port is arranged in the second housing chamber, and the case is provided with a communication passage that communicates the first housing chamber with the second housing chamber, The communicating passage is arranged so as to be located above both the lowest point of the end of the first accommodating chamber on the second axial side and the lowest point of the end of the second accommodating chamber on the first axial side when the rotor axis is horizontal, and the first accommodating chamber is provided with an oil supply structure that uses the flow of oil in the first accommodating chamber generated by the rotation of the rotor to send oil in the first accommodating chamber to the communicating passage.

[0010] According to this characteristic configuration, the communication passage is located above the lowest part of the second housing chamber at the end on the first axial side. As a result, even if the oil level in the case tilts upward from the second housing chamber to the first housing chamber due to factors such as tilting the vehicle drive device or acceleration acting on the vehicle drive device, only the oil in the second housing chamber located above the communication passage flows through the communication passage toward the first housing chamber, while the remaining oil remains in the second housing chamber. Furthermore, according to this characteristic configuration, the oil supply structure of the first housing chamber allows the oil in the first housing chamber to be sent to the communication passage by utilizing the flow of oil in the first housing chamber caused by rotation of the rotor. This reduces the amount of oil in the first housing chamber, reducing the agitation resistance of the rotor and ensuring a large amount of oil in the second housing chamber. Thus, according to this characteristic configuration, oil can be appropriately supplied to the second housing chamber, where the intake port is located, without providing a catch tank or the like. Therefore, while keeping the number of parts to a minimum, even if the oil level in the case slopes upward as it moves from the second storage chamber to the first storage chamber, a sufficient amount of oil can be secured in the second storage chamber where the intake port is located.

[0011] A cross-sectional view along the axial direction of the vehicle drive device according to the embodiment. A skeleton diagram of the vehicle drive device according to the embodiment. A schematic diagram showing the configuration of the case when the rotor axis is horizontal. A schematic diagram showing the configuration of the case when the oil level in the case is inclined upward as it moves from the second housing chamber to the first housing chamber. A diagram showing the communication passage and the oil feed structure as seen from the axial direction.

[0012] Hereinafter, a vehicle drive device 100 according to an embodiment will be described with reference to the drawings.

[0013] As shown in Figures 1 and 2, the vehicle drive device 100 includes a rotating electric machine 1 having a stator 11 and a rotor 12, an output member 2 that is drivingly connected to a wheel W (see Figure 2), a power transmission mechanism 3 that transmits power between the rotor 12 and the output member 2, and a case 9 that houses the rotating electric machine 1 and the power transmission mechanism 3.

[0014] Here, in this application, the term "driving connection" refers to a state in which two rotating elements are connected so as to be able to transmit a driving force, and includes a state in which the two rotating elements are connected so as to rotate integrally, or a state in which the two rotating elements are connected so as to be able to transmit a driving force via one or more transmission members. Such transmission members include various members that transmit rotation at the same speed or at a variable speed, such as a shaft, a gear mechanism, a belt, a chain, etc. Note that the transmission members may also include engagement devices that selectively transmit rotation and driving force, such as friction engagement devices and meshing engagement devices.

[0015] In the following description, the direction along the rotor axis X, which is the rotation axis of the rotor 12, is referred to as the "axial direction L." One side of the axial direction L is referred to as the "axial first side L1," and the other side of the axial direction L is referred to as the "axial second side L2." The direction perpendicular to the rotor axis X is referred to as the "radial direction R." In the radial direction R, the side of the rotor axis X is referred to as the "radial inner side R1," and the opposite side is referred to as the "radial outer side R2."

[0016] The rotating electric machine 1 functions as a driving force source for the pair of wheels W. The rotating electric machine 1 has a function as a motor (electric motor) that receives a supply of electric power to generate power, and a function as a generator that receives a supply of power to generate electric power. Specifically, the rotating electric machine 1 is electrically connected to an electric storage device (not shown), such as a battery or a capacitor. The rotating electric machine 1 generates driving force by running using electric power stored in the electric storage device. The rotating electric machine 1 also generates power using driving force transmitted from the pair of wheels W, thereby charging the electric storage device.

[0017] As shown in FIG. 1 , the stator 11 of the rotating electric machine 1 includes a stator core 11a. The stator core 11a is fixed to a case 9. The stator core 11a is formed in a cylindrical shape. The rotor 12 of the rotating electric machine 1 includes a rotor core 12a. The rotor core 12a is supported rotatably relative to the stator core 11a. The rotor core 12a is formed in a cylindrical shape. The rotor core 12a is disposed adjacent to the stator core 11a in the radial direction R. In this embodiment, the rotor core 12a is coupled to a rotor shaft 12b formed to extend along the axial direction L so as to rotate integrally with the rotor shaft 12b.

[0018] In this embodiment, the stator core 11a is disposed on the radially outer side R2 of the rotor core 12a (rotor 12). The rotor shaft 12b is disposed on the radially inner side R1 of the rotor core 12a. Thus, in this embodiment, the rotating electric machine 1 is an inner rotor type rotating electric machine.

[0019] In this embodiment, the rotating electric machine 1 is a rotating field type rotating electric machine. Therefore, the stator 11 includes a stator coil. In this embodiment, the stator coil is wound around the stator core 11a so as to form a first coil end portion 11b that protrudes toward a first axial side L1 relative to the stator core 11a and a second coil end portion 11c that protrudes toward a second axial side L2 relative to the stator core 11a. Although not shown, the rotor 12 includes a permanent magnet embedded in the rotor core 12a.

[0020] As shown in FIGS. 1 and 2 , in this embodiment, the power transmission mechanism 3 includes a speed reducer 4 and a differential gear mechanism 5 .

[0021] In this embodiment, the reducer 4 and the differential gear mechanism 5 are arranged on the rotor axis X. That is, in this embodiment, the rotor 12 of the rotating electric machine 1, the reducer 4, and the differential gear mechanism 5 are arranged coaxially. In the illustrated example, the rotor 12, the reducer 4, and the differential gear mechanism 5 are arranged in the order shown from the first axial side L1 toward the second axial side L2.

[0022] The reducer 4 is configured to reduce the rotation speed of the rotor 12. In this embodiment, the reducer 4 is a planetary gear mechanism including a sun gear SG, a carrier CR, a first ring gear RG1, and a second ring gear RG2.

[0023] The sun gear SG is connected to the rotor 12 so as to rotate integrally with the rotor 12. In the example shown in Fig. 1, the sun gear SG is connected to the rotor shaft 12b by welding so as to rotate integrally with the rotor shaft 12b.

[0024] The carrier CR is configured to rotatably support the first pinion gear PG1 and the second pinion gear PG2. The first pinion gear PG1 and the second pinion gear PG2 are connected to rotate integrally with each other. The first pinion gear PG1 meshes with the sun gear SG and the first ring gear RG1. The second pinion gear PG2 meshes with the second ring gear RG2. In this embodiment, the second pinion gear PG2 is disposed on the second axial side L2 relative to the first pinion gear PG1. The second pinion gear PG2 is formed to have a smaller diameter than the first pinion gear PG1.

[0025] The first ring gear RG1 is fixed to the case 9. The second ring gear RG2 is supported by the case 9 so as to be rotatable.

[0026] The differential gear mechanism 5 is configured to distribute the driving force transmitted from the reducer 4 to a pair of output members 2, each of which is drivingly connected to a wheel W. In this embodiment, the differential gear mechanism 5 includes a differential case 51, a shaft member 52, a first bevel gear 53, and a pair of second bevel gears 54.

[0027] The differential case 51 is configured to rotate about the rotor axis X. The differential case 51 is an input element of the differential gear mechanism 5. In this embodiment, the differential case 51 is connected to the second ring gear RG2 of the reducer 4 so as to rotate integrally therewith.

[0028] The shaft member 52 is supported by the differential gear case 51 so as to rotate integrally with the differential gear case 51. The shaft member 52 is formed to extend along the radial direction R. In the present embodiment, the shaft member 52 is configured to be formed radially along the radial direction R (for example, configured to be formed in a cross shape when viewed in the axial direction along the axial direction L).

[0029] The first bevel gear 53 is rotatably supported by the shaft member 52. More specifically, the first bevel gear 53 is configured to be rotatable (spin) about its own axis and to be rotatable (revolve) about the rotor axis X. In this embodiment, a plurality of first bevel gears 53 are arranged along the direction of their revolution.

[0030] The pair of second bevel gears 54 are arranged separately on both sides of the shaft member 52 in the axial direction L. The pair of second bevel gears 54 mesh with the first bevel gear 53. The pair of second bevel gears 54 are configured to rotate about the rotor axis X. The pair of second bevel gears 54 are respectively connected to the pair of output members 2 so as to rotate integrally with them.

[0031] In the following description, of the pair of output members 2, the output member 2 arranged on the first axial side L1 will be referred to as the "first output member 2A," and the output member 2 arranged on the second axial side L2 will be referred to as the "second output member 2B."

[0032] In this embodiment, the first output member 2A includes an output shaft portion 21A and a first connecting portion 22A.

[0033] The output shaft portion 21A is formed to extend along the axial direction L. In this embodiment, the output shaft portion 21A is disposed to penetrate the sun gear SG of the reducer 4 and the rotor shaft 12b of the rotating electrical machine 1 in the axial direction L on the radially inner side R1. In this embodiment, the output shaft portion 21A is coupled to rotate integrally with a first drive shaft DS1 (see FIG. 2 ) that is drivingly coupled to a wheel W on a first axial side L1.

[0034] The first connecting portion 22A is connected to the output shaft portion 21A so as to rotate integrally with the output shaft portion 21A. In this embodiment, the first connecting portion 22A is formed in a cylindrical shape having an axis along the axial direction L. The first connecting portion 22A is arranged to cover the output shaft portion 21A from the radially outer side R2. In the example shown in FIG. 1 , the output shaft portion 21A is inserted into the radially inner side R1 of the first connecting portion 22A from the axially first side L1, and they are connected to each other by spline engagement.

[0035] In the present embodiment, the second output member 2B includes a second coupling portion 22B. The second coupling portion 22B is coupled to a second drive shaft DS2 (see FIG. 2 ) that is drivingly coupled to a wheel W on a second axial side L2 so as to rotate integrally with the second coupling portion 22B. In the present embodiment, the second coupling portion 22B is formed in a cylindrical shape with an axis along the axial direction L. In the example shown in FIG. 1 , the second coupling portion 22B is configured such that the second drive shaft DS2 is inserted from the second axial side L2 to the radially inner side R1 of the second coupling portion 22B, and the second drive shaft DS2 and the second coupling portion 22B are coupled to each other by spline engagement.

[0036] The case 9 accommodates the rotating electric machine 1 and the power transmission mechanism 3. The case 9 also accommodates oil F used to cool and lubricate the rotating electric machine 1 and the power transmission mechanism 3. The case 9 includes a first accommodation chamber C1 and a second accommodation chamber C2. In other words, the first accommodation chamber C1 and the second accommodation chamber C2 are formed inside the case 9. The first accommodation chamber C1 accommodates at least a portion of the rotating electric machine 1. The second accommodation chamber C2 accommodates the power transmission mechanism 3. The second accommodation chamber C2 is disposed on a second axial side L2 relative to the first accommodation chamber C1.

[0037] In this embodiment, the case 9 includes a first housing member 91 , a second housing member 92 , a support member 93 , and a cover member 94 .

[0038] The first housing member 91 includes a first peripheral wall portion 911 and a pressure contact portion 912 .

[0039] The first peripheral wall portion 911 is formed in a cylindrical shape having an axis along the axial direction L. The first peripheral wall portion 911 is disposed so as to cover the rotating electrical machine 1 from the radial outside R2.

[0040] The press-contact portion 912 is configured to be in press contact with the stator core 11a from the radially outer side R2. In this embodiment, the press-contact portion 912 is formed in a cylindrical shape that protrudes from the first peripheral wall portion 911 toward the radially inner side R1. The inner circumferential surface of the press-contact portion 912 and the outer circumferential surface of the stator core 11a are in press contact with each other. In this example, the stator core 11a is press-fitted into the press-contact portion 912 from the axial second side L2.

[0041] The second accommodating member 92 is disposed on the second axial side L2 with respect to the first accommodating member 91. The second accommodating member 92 includes a second peripheral wall portion 921 and a side wall portion 922.

[0042] The second circumferential wall portion 921 is formed in a cylindrical shape with an axis aligned with the axial direction L. The second circumferential wall portion 921 is disposed so as to cover the reducer 4 and the differential gear mechanism 5 from the radial outer side R2. The second circumferential wall portion 921 is joined to the first circumferential wall portion 911 from the second axial side L2.

[0043] The side wall portion 922 is formed to extend along the radial direction R. The side wall portion 922 is arranged to cover the differential gear mechanism 5 from the second axial side L2. In the present embodiment, the second connecting portion 22B of the second output member 2B is arranged to penetrate the side wall portion 922 in the axial direction L. In the example shown in FIG. 1 , the second circumferential wall portion 921 and the side wall portion 922 are integrally formed such that an end portion of the second axial side L2 of the second circumferential wall portion 921 and an end portion of the side wall portion 922 on the radially outer side R2 are connected. That is, in the present example, the second accommodating member 92 is formed in a cylindrical shape with a bottom that opens to the first axial side L1.

[0044] The support member 93 is formed to extend along the radial direction R. In this embodiment, the support member 93 rotatably supports the rotor shaft 12b of the rotating electric machine 1 from the radial outside R2, and rotatably supports the carrier CR of the speed reducer 4 from the first axial side L1. Furthermore, the support member 93 non-rotatably supports the first ring gear RG1. In this embodiment, the support member 93 is fixed to the second housing member 92. In the illustrated example, the support member 93 is fixed to the second circumferential wall portion 921 of the second housing member 92 from the first axial side L1 by bolts.

[0045] The cover member 94 is formed to close the opening on the first axial side L1 of the first housing member 91. The cover member 94 is joined to the first axial side L1 of the first peripheral wall portion 911 of the first housing member 91. In the present embodiment, the output shaft portion 21A of the first output member 2A is arranged to pass through the cover member 94 in the axial direction L.

[0046] As described above, in this embodiment, the press-contact portion 912 of the case 9 is in press-contact with the stator core 11a from the radially outer side R2. The rotor core 12a is disposed adjacent to the stator core 11a from the radially inner side R1. Therefore, in this embodiment, the internal space of the case 9 is partitioned in the axial direction L by the press-contact portion 912, the stator core 11a, and the rotor core 12a.

[0047] In this embodiment, the first housing chamber C1 corresponds to an area in the internal space of the case 9 on the first axial side L1 relative to the press-contact portion 912, the stator core 11a, and the rotor core 12a, i.e., an area surrounded by the first circumferential wall portion 911, the press-contact portion 912, the stator core 11a, the rotor core 12a, and the cover member 94. Therefore, in this embodiment, the first housing chamber C1 houses the first coil end portion 11b as part of the rotating electric machine 1.

[0048] In addition, in this embodiment, the area in the internal space of the case 9 on the second axial side L2 relative to the pressure contact portion 912, the stator core 11a, and the rotor core 12a, that is, the area surrounded by the first circumferential wall portion 911, the pressure contact portion 912, the stator core 11a, the rotor core 12a, the second circumferential wall portion 921, and the side wall portion 922, corresponds to the second accommodating chamber C2.

[0049] 1 , the vehicle drive system 100 includes an oil pump 6. The oil pump 6 is configured to draw in oil F from a suction port 61 in a case 9 and discharge the oil. In this embodiment, the oil pump 6 is driven by a dedicated driving power source (e.g., an electric motor) that is independent of the power transmission path between the rotor 12 and the output member 2.

[0050] The suction port 61 is disposed in the second storage chamber C2. More specifically, the suction port 61 is disposed in a lower portion of the second storage chamber C2 so as to be able to draw in the oil F stored in the second storage chamber C2. The suction port 61 may be opened to the case 9 so as to communicate with a strainer disposed in a location separate from the second storage chamber C2, or may be opened to the strainer disposed in the second storage chamber C2 itself. The strainer is a filter that removes foreign matter contained in the oil F drawn in through the suction port 61.

[0051] The vehicle drive device 100 does not include a storage unit such as a catch tank for temporarily storing the oil F drawn from the intake port 61 by the oil pump 6. In this embodiment, an oil passage is provided so that the oil F drawn from the intake port 61 by the oil pump 6 passes through an oil cooler (not shown) that cools the oil F, and is then supplied to objects to be cooled and lubricated (e.g., coil end portions 11b, 11c, gears, bearings, etc.) of the rotating electric machine 1 and the power transmission mechanism 3.

[0052] 3 and 4, the case 9 is provided with a communication passage 95 that connects the first storage chamber C1 and the second storage chamber C2. Each of Fig. 3 and Fig. 4 is a schematic diagram showing the configuration of the case 9. In Fig. 3 and Fig. 4, the direction indicated by "V" is the vertical direction.

[0053] As shown in Figure 3, when the rotor axis X is horizontal, the communicating passage 95 is positioned above both the first lowest point B1, which is the lowest point of the end of the first accommodating chamber C1 on the second axial side L2, and the second lowest point B2, which is the lowest point of the end of the second accommodating chamber C2 on the first axial side L1.

[0054] Therefore, as shown in Fig. 4, when the oil level (surface of the oil F) in the case 9 tilts upward as it moves from the second storage chamber C2 to the first storage chamber C1 due to the tilt of the vehicle drive device 100 or acceleration acting on the vehicle drive device 100, only the oil F in the second storage chamber C2 that is located above the communication passage 95 flows through the communication passage 95 toward the first storage chamber C1, and the remaining oil F remains in the second storage chamber C2. At this time, the intake port 61 is positioned so as to be located below the surface of the oil F that remains in the second storage chamber C2. Note that in the example shown in Fig. 4, the vehicle drive device 100 is tilted so that the first storage chamber C1 is located below the second storage chamber C2.

[0055] This allows the total amount of oil F in the case 9 to be reduced while locating the intake port 61 in the oil F, compared to a configuration in which oil F does not remain in the second storage chamber C2 when the oil level in the case 9 slopes upward as it moves from the second storage chamber C2 to the first storage chamber C1.

[0056] The first storage chamber C1 and the second storage chamber C2 may be formed so that the first lowest portion B1 and the second lowest portion B2 are at the same height or at different heights when the rotor axis X is horizontal. However, in a configuration in which the second lowest portion B2 is located below the first lowest portion B1 when the rotor axis X is horizontal, if the first storage chamber C1 and the second storage chamber C2 are connected without the communication passage 95, the relative positions of the first lowest portion B1 and the second lowest portion B2 are set such that when the oil level (surface of the oil F) in the case 9 slopes upward from the second storage chamber C2 toward the first storage chamber C1, not enough oil F remains in the second storage chamber C2 (the entire suction port 61 is not located in the oil F).

[0057] In this embodiment, the communication passage 95 includes a first opening 951 , a second opening 952 , and a communication hole 953 .

[0058] The first opening 951 opens to the first housing chamber C1. In the present embodiment, the first opening 951 opens to a surface of the pressure contact portion 912 that constitutes the first housing chamber C1, the surface facing the first axial side L1.

[0059] The second opening 952 opens to the second accommodation chamber C2. In the present embodiment, the second opening 952 opens to a surface of the pressure contact portion 912 that constitutes the second accommodation chamber C2, the surface facing the second axial side L2.

[0060] The communication hole 953 is formed in the case 9 so as to communicate between the first opening 951 and the second opening 952. In this embodiment, the communication hole 953 is formed in the press-contact portion 912 along the rotor axis X (see FIG. 1 ). That is, in this embodiment, the communication hole 953 is formed so that the first opening 951 and the second opening 952 are at the same height when the rotor axis X is horizontal.

[0061] 5, the first storage chamber C1 is provided with an oil feed structure 7. The oil feed structure 7 is configured to feed the oil F in the first storage chamber C1 to the communication passage 95 by utilizing the flow of the oil F in the first storage chamber C1 that is generated by the rotation of the rotor 12.

[0062] In this embodiment, the oil conveying structure 7 includes an arrangement of a first opening 951 of the communication passage 95 .

[0063] 1, in this embodiment, the first opening 951 opens in a region on the first axial side L1 with respect to the stator core 11a. In the example shown in Fig. 1, the first opening 951 is arranged so as to overlap with the first coil end portion 11b when viewed in the radial direction R. Here, with regard to the arrangement of two elements, "overlapping when viewed in a specific direction" means that when an imaginary line parallel to the line of sight is moved in each direction perpendicular to the imaginary line, there is at least a region in which the imaginary line intersects both of the two elements.

[0064] Furthermore, as shown in Fig. 5 , in this embodiment, the first opening 951 is open to a region downstream of the flow of oil F toward the radially outer side R2 caused by the rotation of the rotor 12. In this embodiment, the "downstream side of the flow of oil F toward the radially outer side R2 caused by the rotation of the rotor 12" refers to a region obtained by extending a tangent to the outer peripheral surface of the rotor core 12a toward the side where the contact point of the tangent moves due to the rotation of the rotor 12, as viewed in the axial direction L. In the example shown in Fig. 5 , the rotor 12 rotates clockwise (see the white arrow in Fig. 5 ). The first opening 951 is located on the left side of the rotor 12 in Fig. 5 .

[0065] In the present embodiment, the oil feed structure 7 includes a guide path 71. The guide path 71 is provided in the case 9 so as to guide the flow of oil F generated by the rotation of the rotor 12 to the first opening 951. In the example shown in FIG. 1 , the guide path 71 is a groove formed in the cover member 94 of the case 9.

[0066] As shown in Figure 5, in this embodiment, when the oil level in the case 9 slopes upward as it moves from the second storage chamber C2 to the first storage chamber C1 (see Figure 4), the rotor 12 is positioned and the total amount of oil F in the case 9 is set so that the lower end of the rotor core 12a is located below the oil level in the first storage chamber C1.

[0067] Therefore, in this embodiment, the rotor core 12a stirs the oil F stored in the first storage chamber C1 as the rotor 12 rotates. As a result, the oil F stored in the first storage chamber C1 flows along the guide path 71 toward the first opening 951 (see the black arrows in FIG. 5 ). Then, due to pressure caused by the height of the oil level in a portion where the oil level has risen unevenly due to the rotation of the rotor 12, some of the oil F that has flowed toward the first opening 951 passes through the communication hole 953 and is supplied from the second opening 952 to the second storage chamber C2.

[0068] Other Embodiments (1) In the above embodiment, a configuration has been described as an example in which, when the oil level in the case 9 slopes upward from the second housing chamber C2 to the first housing chamber C1, the lower end of the rotor core 12a is located below the oil level in the first housing chamber C1. However, the present invention is not limited to such a configuration. When the oil level in the case 9 slopes upward from the second housing chamber C2 to the first housing chamber C1, the lower end of the rotor core 12a may be located above the oil level in the first housing chamber C1. In this case, as the rotor 12 rotates, oil F splashes from the rotor core 12a and flows along the guide path 71 toward the first opening 951.

[0069] (2) In the above embodiment, the rotor core 12a is used to generate a flow in the oil F. However, the present invention is not limited to such a configuration, and the flow in the oil F may be generated by a scraping member such as a fin that rotates integrally with the rotor 12.

[0070] (3) In the above embodiment, the guide path 71 is a groove formed on the inner surface of the case 9. However, the present invention is not limited to such a configuration. For example, the guide path 71 may be a protrusion formed on the inner surface of the case 9. Furthermore, the guide path 71 may be formed of a member fixed to the inner surface of the case 9.

[0071] (4) In the above embodiment, the power transmission mechanism 3 includes the reducer 4 and the differential gear mechanism 5, and the rotor 12, the reducer 4, and the differential gear mechanism 5 are arranged coaxially. However, the present invention is not limited to such a configuration. For example, the power transmission mechanism 3 may include elements arranged across multiple axes, or the power transmission mechanism 3 and the rotor 12 may be arranged across multiple axes. Furthermore, the power transmission mechanism 3 may include an engagement device such as a clutch or a brake.

[0072] (5) In the above embodiment, the output member 2 is connected to the second bevel gear 54 of the differential gear mechanism 5 so as to rotate integrally with the second bevel gear 54. However, the present invention is not limited to such a configuration. For example, in a configuration in which the power transmission mechanism 3 does not include a differential gear mechanism 5, the output member 2 may be connected to the wheels W so as to rotate integrally with the wheels W.

[0073] (6) Note that the configurations disclosed in the above-described embodiments can be applied in combination with configurations disclosed in other embodiments, as long as no contradictions arise. Regarding other configurations, the embodiments disclosed in this specification are merely examples in all respects. Therefore, various modifications can be made as appropriate within the scope of the present disclosure.

[0074] Summary of the Present Embodiment The following provides an overview of the vehicle drive device (100) described above.

[0075] The vehicle drive device (100) includes: a rotating electric machine (1) having a rotor (12); an output member (2) drivingly connected to a wheel (W); a power transmission mechanism (3) that transmits power between the rotor (12) and the output member (2); a case (9) that houses the rotating electric machine (1) and the power transmission mechanism (3); and an oil pump (6) that draws in oil (F) in the case (9) from an intake port (61) and discharges it, wherein the direction along a rotor axis (X) that is the rotation axis of the rotor (12) is defined as an axial direction (L), one side of the axial direction (L) is defined as an axial first side (L1), and the other side of the axial direction (L) is defined as an axial second side (L2), the case (9) comprises a first housing chamber (C1) in which at least a part of the rotating electric machine (1) is housed, and a second housing chamber (C2) that is disposed on the second axial side (L2) with respect to the first housing chamber (C1) and houses the power transmission mechanism (3), the suction port (61) is disposed in the second housing chamber (C2), the case (9) is provided with a communication passage (95) that communicates the first housing chamber (C1) and the second housing chamber (C2), and the communication passage (95) is disposed so as to be located above both a bottom part (B1) of an end of the first housing chamber (C1) on the second axial side (L2) and a bottom part (B2) of an end of the second housing chamber (C2) on the first axial side (L1) when the rotor axis center (X) is horizontal, The first storage chamber (C1) is provided with an oil supply structure (7) that uses the flow of oil (F) in the first storage chamber (C1) generated by the rotation of the rotor (12) to supply the oil (F) in the first storage chamber (C1) to the communication passage (95).

[0076] According to this configuration, the communication passage (95) is disposed above the lowermost portion (B2) of the end portion of the second storage chamber (C2) on the first axial side (L1). As a result, even when the oil level in the case (9) tilts upward from the second storage chamber (C2) to the first storage chamber (C1) due to the inclination of the vehicle drive device (100) or acceleration acting on the vehicle drive device (100), only the oil (F) located above the communication passage (95) in the second storage chamber (C2) flows through the communication passage (95) toward the first storage chamber (C1), and the remaining oil (F) remains in the second storage chamber (C2). Furthermore, according to this configuration, the oil supply structure (7) of the first storage chamber (C1) can utilize the flow of oil (F) in the first storage chamber (C1) generated by the rotation of the rotor (12) to supply the oil (F) in the first storage chamber (C1) to the communication passage (95). This reduces the amount of oil (F) in the first storage chamber (C1), reducing the agitation resistance of the oil (F) caused by the rotor (12), and ensuring a large amount of oil (F) in the second storage chamber (C2). Thus, according to this configuration, the oil (F) can be appropriately supplied to the second storage chamber (C2) in which the suction port (61) is located without providing a catch tank or the like. Therefore, even if the oil level in the case (9) slopes upward from the second storage chamber (C2) toward the first storage chamber (C1), the number of parts can be kept small, and a sufficient amount of oil (F) can be ensured in the second storage chamber (C2) in which the suction port (61) is located.

[0077] Here, a direction perpendicular to the rotor axis (X) is defined as a radial direction (R), and the rotating electric machine (1) includes a stator core (11a) arranged on the outside (R2) of the radial direction (R) with respect to the rotor (12), and the communication passage (95) includes a first opening (951) opening to the first accommodating chamber (C1), a second opening (952) opening to the second accommodating chamber (C2), and a communication hole (953) formed in the case (9) so as to communicate between the first opening (951) and the second opening (952), and the oil supply structure (7) preferably includes an arrangement of the first opening (951) on the first axial side (L1) with respect to the stator core (11a), and opening to a region downstream of a flow of oil (F) directed toward the outside (R2) in the radial direction (R) caused by rotation of the rotor (12).

[0078] This configuration makes it possible to facilitate the flow of the oil (F) in the first storage chamber (C1) into the communication passage (95), thereby enabling the oil (F) in the first storage chamber (C1) to be appropriately sent to the second storage chamber (C2).

[0079] In the above configuration, it is preferable that the oil supply structure (7) includes a guide path (71) provided in the case (9) so as to guide the flow of oil (F) generated by the rotation of the rotor (12) to the first opening (951).

[0080] According to this configuration, the oil (F) in the first storage chamber (C1) can be efficiently caused to flow into the communication passage (95), and therefore the oil (F) in the first storage chamber (C1) can be appropriately sent to the second storage chamber (C2).

[0081] The above-mentioned configuration including the communication passage (95) and the oil supply structure (7) is suitable when the power transmission mechanism (3) includes a reducer (4) that reduces the rotation speed of the rotor (12) and a differential gear mechanism (5) that distributes the driving force transmitted from the reducer (4) to a pair of output members (2) that are each drivingly connected to a wheel (W), and the rotor (12), the reducer (4), and the differential gear mechanism (5) are arranged coaxially.

[0082] This is because, in this configuration, the axial (L) dimension of the case (9) is likely to become large, and the axial (L) deviation of the oil level in the case (9) is likely to become large due to factors such as the inclination of the vehicle drive device (100) and acceleration acting on the vehicle drive device (100).

[0083] The technology disclosed herein can be used in a vehicle drive device that includes a rotating electric machine with a rotor, an output member that is drivingly connected to a wheel, a power transmission mechanism that transmits power between the rotor and the output member, a case that houses the rotating electric machine and the power transmission mechanism, and an oil pump that draws oil from the case through an intake port and discharges it.

[0084] 100: Vehicle drive device, 1: Rotating electric machine, 11: Stator, 11a: Stator core, 12: Rotor, 12a: Rotor core, 2: Output member, 3: Power transmission mechanism, 4: Reducer, 5: Differential gear mechanism, 6: Oil pump, 61: Inlet port, 7: Oil feed structure, 71: Guide path, 9: Case, 95: Communication passage, 951: First opening, 952: Second opening, 953: Communication hole, C1: First housing chamber, C2: Second housing chamber, F: Oil, W: Wheel, X: Rotor axis, L: Axial direction, L1: Axial first side, L2: Axial second side, R: Radial direction

Claims

1. A vehicle drive device comprising: a rotating electric machine having a rotor; an output member drivingly connected to a wheel; a power transmission mechanism for transmitting power between the rotor and the output member; a case accommodating the rotating electric machine and the power transmission mechanism; and an oil pump for drawing in and discharging oil from the case through an intake port, wherein the direction along the rotor axis, which is the rotational axis of the rotor, is defined as the axial direction, one side in the axial direction is defined as the first axial side, and the other side in the axial direction is defined as the second axial side, the case comprising a first housing chamber in which at least a part of the rotating electric machine is accommodated, and a second housing chamber located on the second axial side of the first housing chamber and in which the power transmission mechanism is accommodated, the intake port is located in the second housing chamber, and the case is provided with a communication passage communicating the first housing chamber with the second housing chamber, the communicating passage is arranged so as to be located above both the lowest point of the end of the first accommodating chamber on the second axial side and the lowest point of the end of the second accommodating chamber on the first axial side when the rotor axis is horizontal, and the first accommodating chamber is provided with an oil supply structure that uses the flow of oil in the first accommodating chamber generated by rotation of the rotor to send oil in the first accommodating chamber to the communicating passage.

2. A vehicle drive device as described in claim 1, wherein a direction perpendicular to the rotor axis is defined as a radial direction, the rotating electric machine comprises a stator core arranged radially outward from the rotor, the communication passage comprises a first opening opening into the first accommodating chamber, a second opening opening into the second accommodating chamber, and a communication hole formed in the case so as to communicate the first opening with the second opening, and the oil feed structure includes an arrangement of the first opening on the first axial side of the stator core and opening to a region downstream of the flow of oil directed radially outward caused by rotation of the rotor.

3. A vehicle drive device according to claim 2, wherein the oil supply structure includes a guide path provided in the case so as to guide the flow of oil generated by the rotation of the rotor to the first opening.

4. A vehicle drive device as described in any one of claims 1 to 3, wherein the power transmission mechanism comprises a reducer that reduces the rotation of the rotor, and a differential gear mechanism that distributes the driving force transmitted from the reducer to a pair of output members that are each drivingly connected to wheels, and the rotor, reducer, and differential gear mechanism are arranged coaxially.

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