Vehicle drive device

Abstract

To reduce a physical constitution of an entire part of a vehicle drive device in a vertical direction.SOLUTION: A vehicle drive device includes: a rotary electric machine; a transmission mechanism; an inverter device; a case having a first case part which houses the rotary electric machine; and a rotor shaft to which a rotor is fixed. The rotary electric machine and a pair of output members are disposed having two axes. The transmission mechanism includes an output gear, which is connected to at least one of the pair of output members in a drivable manner, coaxially with the pair of output members. The output gear is arranged so as to overlap with the rotary electric machine and the inverter device when viewed in an axial direction. The inverter device is arranged so as to overlap with a first output member, which is one of the pair of output members, when viewed in a vertical direction. The first output member is arranged so as to overlap with the rotor shaft when viewed in a horizontal direction, and the inverter device is arranged below an uppermost position of the first case part in a second direction. The vehicle drive device is disclosed.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a vehicle drive device. [Background technology]

[0002] A technology is known in which an output member that is drivingly connected to a wheel is positioned offset in the vertical direction relative to a rotor shaft to which the rotor of a rotating electric machine is fixed, without overlapping horizontally, thereby utilizing a space lower than the highest point in the case and on one side and above the rotating electric machine in the horizontal direction (see, for example, Figure 4 of Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Patent Publication No. 2021 / 140712 Brochure Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-described conventional technology, the output member that is drivingly connected to the wheels is arranged offset in the vertical direction relative to the rotor shaft without overlapping when viewed horizontally, making it difficult to reduce the vertical size of the vehicle drive device as a whole.

[0005] Therefore, in one aspect, an object of the present disclosure is to reduce the overall vertical size of a vehicle drive device. [Means for solving the problem]

[0006] According to one aspect of the present disclosure, there is provided a rotating electric machine having a rotor and a stator; a first output member that is one of a pair of output members that are drivingly connected to the pair of wheels, respectively; a transmission mechanism that transmits a driving force between the rotary electric machine and the pair of output members; an inverter device that receives power from a battery and supplies power to the rotating electric machine; a case having a first case portion that houses the rotating electric machine, a second case portion that houses the transmission mechanism, and a third case portion that houses the inverter device; a rotor shaft to which the rotor is fixed so as not to rotate and which is supported by the case, The rotating electric machine and the pair of output members are arranged on two parallel shafts, the transmission mechanism includes an output gear drivingly connected to at least one of the pair of output members, the output gear being coaxial with the pair of output members; the output gear is disposed so as to overlap with each of the rotating electric machine and the inverter device when viewed in the axial direction, the inverter device is disposed so as to overlap with the transmission mechanism or the first output member when viewed in the up-down direction, A vehicle drive device is provided in which the pair of output members are arranged so as to overlap with the axis of the rotor shaft when viewed in the direction along the vehicle fore-and-aft direction, and the inverter device is arranged below the uppermost position of the first case portion in the vertical direction. [Effects of the Invention]

[0007] According to one aspect, the present disclosure makes it possible to reduce the overall size of the vehicle drive device in the vertical direction. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic top view showing a state in which a vehicle drive device is mounted in a vehicle. [Figure 2] 1 is a cross-sectional view of a main part of a vehicle drive device. [Figure 2A] FIG. 1 is a skeleton diagram showing a vehicle drive device. [Figure 3] 1A and 1B are three-view diagrams schematically illustrating a vehicle drive device according to a first embodiment. [Figure 4] 1 is a diagram schematically illustrating a vehicle drive device according to a first embodiment as viewed in the axial direction. [Figure 5] 1 is a diagram schematically illustrating a vehicle drive device according to a first embodiment as viewed in an axial direction from a first axial side. [Figure 6] FIG. 6 is an explanatory diagram of a modification of FIG. 5. [Figure 7] 2 is a diagram showing a schematic view of the inside of the vehicle drive device according to the first embodiment as viewed from a first axial side. FIG. [Figure 8] 10A and 10B are two-sided views schematically illustrating a vehicle drive device according to a second embodiment. [Figure 9] 9 is a diagram schematically illustrating a vehicle drive device according to a second embodiment as viewed in a direction perpendicular to two directions of the two-plane view of FIG. 8. FIG. [Figure 10] FIG. 10 is an explanatory diagram of a modified example of FIG. 9. [Figure 11] 10 is a diagram schematically illustrating a vehicle drive device according to a second embodiment as viewed in the axial direction from a first axial side. FIG. [Figure 12] 10 is a diagram showing a schematic view of the inside of a vehicle drive device according to a second embodiment as viewed from a first axial side. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] Each embodiment will be described in detail below with reference to the accompanying drawings. Note that the dimensional ratios in the drawings are merely examples and are not intended to limit the scope of the invention. In addition, shapes and the like in the drawings may be partially exaggerated for the sake of explanation.

[0010] In the following description, the vertical direction V (see FIG. 2, etc.) refers to the vertical direction when the vehicle drive device 100 is in use, i.e., the vertical direction when the vehicle drive device 100 is oriented in its use state. Because the vehicle drive device 100 is mounted on a vehicle VC (see FIG. 1) for use, the vertical direction V corresponds to the vertical direction when the vehicle drive device 100 is mounted on the vehicle VC (hereinafter referred to as the "vehicle-mounted state"), more specifically, the vertical direction when the vehicle VC is stopped on a flat road (a road along a horizontal surface) in the vehicle-mounted state. The upper side V1 and the lower side V2 refer to the upper side and the lower side in this vertical direction V. In the following description, the directions of each component refer to the directions when the component is assembled in the vehicle drive device 100. Terms related to the dimensions, arrangement direction, arrangement position, etc. of each component are concepts that include differences due to errors (errors that are acceptable in manufacturing).

[0011] In this specification, "driving connection" refers to a state in which two rotating elements are connected so as to be able to transmit a driving force (synonymous with torque), 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 (e.g., shafts, gear mechanisms, belts, chains, etc.) that transmit rotation at a constant speed or at variable speeds. Note that the transmission members may also include engagement devices (e.g., friction engagement devices, meshing engagement devices, etc.) that selectively transmit rotation and driving force.

[0012] In this specification, the term "rotating electric machine" is used to refer to a motor (electric motor), a generator (electric generator), and a motor-generator that functions as both a motor and a generator as needed. Furthermore, in this specification, with respect to the arrangement of two components, "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 portion of an area where the imaginary line intersects with both of the two components. Furthermore, in this specification, with respect to the arrangement of two components, "their arrangement areas in a specific direction overlap" means that the arrangement area of ​​one component in a specific direction includes at least a portion of the arrangement area of ​​the other component in a specific direction.

[0013] Fig. 1 is a schematic top view showing a state in which a vehicle drive device 100 is mounted in a vehicle VC. Fig. 2 is a cross-sectional view of a main part of the vehicle drive device 100. Fig. 2A is a skeleton diagram showing the vehicle drive device 100. Fig. 3 is a three-sided view showing a schematic view of the vehicle drive device 100 according to this embodiment, with a portion shown in perspective so that the interior can be seen.

[0014] As shown schematically in Fig. 1, the vehicle drive device 100 includes a rotating electric machine 1, a pair of output members 6 drivingly connected to a pair of wheels W (see Fig. 1), a transmission mechanism 3 that transmits driving force between the rotating electric machine 1 and the pair of output members 6, and an inverter device 90 that drives and controls the rotating electric machine 1. The vehicle drive device 100 further includes a case 2 that houses the rotating electric machine 1 and the inverter device 90. The case 2 also houses the pair of output members 6 and the transmission mechanism 3.

[0015] The first output member 61, which is one of the pair of output members 6, is drivingly connected to the first wheel W1, which is one of the pair of wheels W, and the second output member 62, which is the other of the pair of output members 6, is drivingly connected to the second wheel W2, which is the other of the pair of wheels W. As shown in FIG. 1 , a vehicle VC on which the vehicle drive device 100 is mounted includes a first drive shaft 63 that rotates integrally with the first wheel W1 and a second drive shaft 64 that rotates integrally with the second wheel W2. The first drive shaft 63 is connected to the first wheel W1 via, for example, a constant velocity joint, and the second drive shaft 64 is connected to the second wheel W2 via, for example, a constant velocity joint. The first output member 61 is connected to the first drive shaft 63 so as to rotate integrally therewith, and the second output member 62 is connected to the second drive shaft 64 so as to rotate integrally therewith.

[0016] The vehicle drive device 100 transmits the output torque of the rotating electric machine 1 to a pair of wheels W via a pair of output members 6, thereby driving the vehicle VC on which the vehicle drive device 100 is mounted. In other words, the rotating electric machine 1 is a driving force source for the pair of wheels W. The pair of wheels W is a pair of left and right wheels of the vehicle VC (for example, a pair of left and right front wheels or a pair of left and right rear wheels). The rotating electric machine 1 may be, for example, an AC rotating electric machine driven by three-phase AC (an example of polyphase AC). The rotating electric machine 1 is electrically connected to a battery BA (including a power storage device such as a capacitor) via an inverter device 90 that performs power conversion between DC power and AC power, and is powered by receiving power from the battery BA, or supplies power generated by the inertial force of the vehicle VC to the power storage device for storage.

[0017] As shown in FIG. 2, the rotating electric machine 1 and the pair of output members 6 are arranged on two parallel axes (specifically, a first axis C1 and a second axis C2). Specifically, the rotating electric machine 1 is arranged on the first axis C1, and the pair of output members 6 are arranged on a second axis C2 different from the first axis C1. The first axis C1 and the second axis C2 are axes (virtual axes) arranged parallel to each other. The transmission mechanism 3 includes an output gear 30 drivingly connected to at least one of the pair of output members 6, coaxially with the pair of output members 6 (i.e., on the second axis C2).

[0018] As shown in FIG. 1, the vehicle drive device 100 is mounted on the vehicle VC with the axial direction A oriented along the left-right direction of the vehicle. The axial direction A is a direction parallel to the first axis C1 and the second axis C2, in other words, an axial direction common to the first axis C1 and the second axis C2. That is, the axial direction A is the direction in which the rotational axis of the rotary electric machine 1 extends and also the direction in which the rotational axis of the pair of output members 6 extends. Here, one side of the axial direction A is referred to as the first axial side A1, and the other side of the axial direction A (the side opposite to the first axial side A1 in the axial direction A) is referred to as the second axial side A2. The first axial side A1 is the side on which the rotary electric machine 1 is disposed with respect to the transmission mechanism 3 in the axial direction A. As shown in FIG. 2, the first output member 61 is the output member 6 of the pair of output members 6 that is disposed on the first axial side A1, and the second output member 62 is the output member 6 of the pair of output members 6 that is disposed on the second axial side A2.

[0019] As shown in Fig. 1, the vehicle drive system 100 may be mounted on the vehicle VC with the first axial side A1 facing the right side of the vehicle and the second axial side A2 facing the left side of the vehicle. In this case, the first wheel W1 to which the first output member 61 is drivingly connected is the right wheel, and the second wheel W2 to which the second output member 62 is drivingly connected is the left wheel. Fig. 1 assumes that the vehicle drive system 100 is a front-wheel drive system that drives a pair of left and right front wheels. Therefore, in the example shown in Fig. 1, the first wheel W1 is the right front wheel, and the second wheel W2 is the left front wheel.

[0020] 2, the rotating electric machine 1 includes a rotor 10 and a stator 11. The stator 11 is fixed to a case 2, and the rotor 10 is supported by the case 2 so as to be rotatable relative to the stator 11. The rotating electric machine 1 may be an inner rotor type rotating electric machine, in which case the rotor 10 may be disposed radially inside the stator 11 so as to overlap with the stator 11 as viewed in the radial direction. The radial direction here is a radial direction based on the first axis C1, in other words, a radial direction based on the rotational axis of the rotating electric machine 1.

[0021] The stator 11 includes a stator core 12 and coil end portions 13 that protrude from the stator core 12 in the axial direction A. A coil is wound around the stator core 12, and the portions of the coil that protrude from the stator core 12 in the axial direction A form the coil end portions 13. The coil end portions 13 are formed on both sides of the stator core 12 in the axial direction A.

[0022] The transmission mechanism 3 includes a reduction gear mechanism 34 in a power transmission path between the rotating electric machine 1 and the output gear 30. The reduction gear mechanism 34 is optional and may include a reduction gear mechanism using a counter gear, a reduction gear mechanism using a planetary gear, or the like. In this embodiment, as an example, the reduction gear mechanism 34 includes a planetary gear mechanism, and is disposed coaxially with the rotating electric machine 1. An output gear (carrier) 342 of the reduction gear mechanism 34 radially meshes with the output gear 30 of the differential gear mechanism 5. Such a vehicle drive device 100 can have a compact configuration consisting of two shafts (a first shaft C1 and a second shaft C2). In a modified example, the vehicle drive device 100 may have three or more shafts.

[0023] In this embodiment, the reduction mechanism 34 is arranged coaxially with the rotating electric machine 1 (i.e., on the first axis C1) in a manner that the reduction mechanism 34 is drivingly connected to the rotating electric machine 1. The input member 16, which meshes with the sun gear 341 of the reduction mechanism 34, is connected to the rotor 10 so as to rotate integrally with the rotor 10. In the example shown in FIG. 2, the vehicle drive device 100 includes a rotor shaft 15 to which the rotor 10 is fixed, and the input member 16 is connected to the rotor shaft 15 so as to rotate integrally with the rotor shaft 15. Specifically, a portion of the input member 16 on the first axial side A1 may be connected (here, spline-connected) to a portion of the rotor shaft 15 on the second axial side A2. Alternatively, the vehicle drive device 100 may have a configuration in which the rotor shaft 15 and the input member 16 are integrally formed as a single piece.

[0024] The transmission mechanism 3 further includes a differential gear mechanism 5. The differential gear mechanism 5 distributes the driving force transmitted from the rotating electric machine 1 side to the pair of output members 6. The differential gear mechanism 5 may be arranged coaxially with the pair of output members 6 (i.e., on the second axis C2). The differential gear mechanism 5 distributes the driving force transmitted from the rotating electric machine 1 side to the output gear 30 to the pair of output members 6. In other words, the output gear 30 is drivingly connected to both of the pair of output members 6 via the differential gear mechanism 5. The differential gear mechanism 5 may be a bevel gear type differential gear mechanism, and the output gear 30 may be connected to a differential case portion 50 included in the differential gear mechanism 5 so as to rotate integrally therewith.

[0025] In the example shown in FIG. 2 , the differential gear mechanism 5 distributes the rotation of the output gear 30 to a first side gear 51 and a second side gear 52. The first side gear 51 rotates integrally with a first output member 61, and the second side gear 52 rotates integrally with a second output member 62. The first side gear 51 may be formed on a member separate from a member (here, a shaft member) constituting the first output member 61, and may be coupled (here, spline-coupled) to the first output member 61 so as to rotate integrally therewith. At least a portion of the first axial side A1 of the first output member 61 is formed in a tubular shape (specifically, a cylindrical shape) extending in the axial direction A, and the first drive shaft 63 (see FIG. 1 ) may be inserted into the interior of the first output member 61 (a space surrounded by the inner circumferential surface) from the first axial side A1. The second output member 62 may be coupled to the second side gear 52. The second output member 62 may be realized by a second drive shaft 64.

[0026] In this embodiment, the output gear 30 of the differential gear mechanism 5 is preferably disposed near the end of the case 2 on the second axial side A2. In this case, a gear (not shown) of the reduction mechanism 34 that meshes with the output gear 30 may be disposed closest to the second axial side A2 of the reduction mechanism 34. In this case, the output gear 30 can be disposed closer to the second axial side A2 of the entire vehicle drive device 100.

[0027] In this embodiment, the case 2 includes an integrated motor case 21, a transmission mechanism case 22, an output shaft case 23, and an inverter case 24. Here, "integrated" includes an integrated configuration using fastening members such as bolts, and an integrated configuration using integral molding (for example, casting or pouring using aluminizing).

[0028] The motor case 21 forms a motor accommodating chamber S1 that accommodates the rotating electric machine 1, the transmission mechanism case 22 forms a transmission mechanism accommodating chamber S2 that accommodates the transmission mechanism 3, the output shaft case 23 forms an output shaft accommodating chamber S3 that accommodates the first output member 61, and the inverter case 24 forms an inverter accommodating chamber S4 that accommodates the inverter device 90. Note that "the motor case 21 forms the motor accommodating chamber S1" means that the wall portions that bound the motor accommodating chamber S1 form the motor case 21. The same applies to the transmission mechanism accommodating chamber S2, the output shaft case 23, and the inverter case 24.

[0029] In this embodiment, since the output shaft case portion 23 is provided, the first output member 61 can be more effectively protected from the external environment (for example, flying stones) than when the first output member 61 is provided outside the case 2. In addition, the clearance that must be secured between the first output member 61 and peripheral components can be reduced.

[0030] The case 2 may be formed by joining multiple members (case members and cover members). Therefore, one case member forming the case 2 may form two or more case members among the motor case 21, the transmission mechanism case 22, the output shaft case 23, and the inverter case 24.

[0031] Furthermore, the motor accommodating chamber S1, the transmission mechanism accommodating chamber S2, the output shaft accommodating chamber S3, and the inverter accommodating chamber S4 formed by the case 2 may be completely isolated from one another, may be partially in communication with one another, or may be shared without any boundaries. For example, the motor accommodating chamber S1 and the output shaft accommodating chamber S3 may be shared without any partition wall separating them. In this case, the rotating electric machine 1 and the first output member 61 are accommodated in the shared accommodation chamber (specifically, the motor accommodating chamber S1 and the output shaft accommodating chamber S3) formed by the case 2.

[0032] In the following description, as an example, the case 2 is formed by joining a case member 200, a motor cover member 201, a differential cover member 202, and an inverter cover member 203. The joining method may be fastening with bolts or the like.

[0033] The case member 200 may be formed as a one-piece member (for example, a single member made of a common material formed by die casting). In this case, the motor accommodating chamber S1 and the transmission mechanism accommodating chamber S2 may be separated by a single partition wall 26.

[0034] The case member 200 is open in the axial direction A on a first axial side A1 and is also open in the axial direction A on a second axial side A2.

[0035] The motor cover member 201 is provided so as to cover the opening on the first axial side A1 of the case member 200 (i.e., the opening on the first axial side A1 of the motor accommodating chamber S1). The motor cover member 201 may be formed as a one-piece member. The motor cover member 201 may be joined to an end face (joint surface) on the first axial side A1 of the case member 200. In this case, the joint surface (mating surface) 221 between the motor cover member 201 and the case member 200 may extend in a plane perpendicular to the axial direction A.

[0036] The differential cover member 202 is provided so as to cover the opening on the second axial side A2 of the case member 200 (i.e., the opening on the second axial side A2 side of the transmission mechanism accommodating chamber S2). The differential cover member 202 may be formed as a one-piece member. The differential cover member 202 may be joined to an end face (joint surface) of the case member 200 on the second axial side A2. In this case, the joint surface (mating surface) 222 between the differential cover member 202 and the case member 200 may extend in a plane perpendicular to the axial direction A.

[0037] The inverter cover member 203 is provided so as to cover the opening of the inverter accommodating chamber S4 in the case member 200. The inverter cover member 203 may be formed as a one-piece member.

[0038] The inverter device 90 may be in the form of a module and may be fixed to a wall portion forming the inverter case 24 with bolts or the like. The inverter device 90 includes a power module PM (described later) including a plurality of switching elements that constitute an inverter circuit, a control board SB (described later) on which a control device that controls the inverter circuit is mounted, and a smoothing capacitor CM (described later) that smoothes the voltage between the positive and negative poles on the DC side of the inverter circuit. The inverter device 90 may further include various sensors such as a current sensor, a filter (not shown) such as a Y capacitor, various wiring (including connectors and bus bars), and the like. The inverter device 90 may also include a cooling water channel (described later) for cooling the power module PM. The smoothing capacitor CM may be in the form of a module formed by molding a plurality of capacitor elements and terminals with resin.

[0039] 3, the direction in which the rotating electric machine 1 and the inverter device 90 are aligned as viewed in the axial direction along the axial direction A is defined as a first direction X, and the direction perpendicular to both the axial direction A and the first direction X is defined as a second direction Y. One side of the first direction X is defined as a first direction first side X1, the other side of the first direction X (the side opposite to the first direction first side X1 in the first direction X) is defined as a first direction second side X2, one side of the second direction Y is defined as a second direction first side Y1, and the other side of the second direction Y (the side opposite to the second direction first side Y1 in the second direction Y) is defined as a second direction second side Y2. The first direction first side X1 is the side on which the rotating electric machine 1 is arranged with respect to the inverter device 90 in the first direction X.

[0040] In the following description, the second direction is assumed to have a vertical component. In this case, the second direction may be parallel to the direction of gravity (vertical direction) or may be inclined with respect to the direction of gravity (vertical direction) when the vehicle drive device 100 is mounted on the vehicle VC. For example, the vehicle drive device 100 may be mounted on the vehicle VC with the second direction first side Y1 being the upper side V1 and the second direction second side Y2 being the lower side V2. Furthermore, the vehicle drive device 100 may be mounted on the vehicle VC with the first direction first side X1 being the front side L1 (the front side in the vehicle longitudinal direction L) and the first direction second side X2 being the rear side L2 (the rear side in the vehicle longitudinal direction L). As shown in FIG. 1, the vehicle drive device 100 may be mounted on the vehicle VC on the front side L1 of the center of the vehicle VC in the vehicle longitudinal direction L. When the vehicle driving device 100 is mounted on the vehicle VC on the rear side L2 of the center of the vehicle in the vehicle longitudinal direction L, the vehicle driving device 100 can be mounted on the vehicle VC with the first direction first side X1 being the rear side L2 and the first direction second side X2 being the front side L1, so that the inverter device 90 is positioned closer to the center of the vehicle in the vehicle longitudinal direction L than the rotating electric machine 1. When the vehicle driving device 100 is mounted on the vehicle VC on the rear side L2 of the center of the vehicle in the vehicle longitudinal direction L in this way, the pair of wheels W driven by the vehicle driving device 100 may be, for example, a pair of left and right rear wheels.

[0041] When the vehicle VC has a pair of left and right front wheels and a pair of left and right rear wheels, one of the pair of left and right front wheels or the pair of left and right rear wheels that is not driven by the vehicle drive device 100 (the pair of left and right rear wheels in the example shown in FIG. 1 ) may be configured to be driven by a drive device other than the vehicle drive device 100. The drive device other than the vehicle drive device 100 may be, for example, a drive device configured to transmit the output torque of an internal combustion engine (an example of a driving force source other than a rotating electric machine) to a pair of wheels to be driven, a drive device configured to transmit the output torque of a rotating electric machine (a rotating electric machine different from the rotating electric machine 1 provided in the vehicle drive device 100) to a pair of wheels to be driven, or a drive device configured to transmit the output torque of both an internal combustion engine and a rotating electric machine (a rotating electric machine different from the rotating electric machine 1 provided in the vehicle drive device 100) to a pair of wheels to be driven. The drive device other than the vehicle drive device 100 may also be a drive device with the same configuration as the vehicle drive device 100.

[0042] Incidentally, the rotating electric machine 1 of the vehicle drive device 100 may have the largest physical size in the second direction as viewed in the axial direction. The physical size of the rotating electric machine 1 is determined depending on the required output, etc. Therefore, in order to reduce the physical size of the vehicle drive device 100 as a whole in the second direction, it is useful to arrange the main components of the vehicle drive device 100 (main components other than the rotating electric machine 1) so that they overlap the rotating electric machine 1 as viewed in the first direction X. In particular, when the vehicle drive device 100 includes an output gear 30 having a relatively large outer diameter, the positional relationship between the output gear 30 and the rotating electric machine 1 can significantly affect the physical size of the vehicle drive device 100 as a whole in the second direction.

[0043] In consideration of this point, in this embodiment, the output gear 30 is preferably disposed with respect to the rotating electric machine 1 so as not to significantly affect the overall size of the vehicle drive device 100 in the second direction. That is, the offset amount in the second direction Y between the central axis of the output gear 30 (i.e., the second axis C2) and the central axis of the rotating electric machine 1 (i.e., the first axis C1) is set to be relatively small. Specifically, a pair of output members 6 concentric with the central axis of the output gear 30 are disposed so as to overlap with the rotor shaft 15 of the vehicle drive device 100 when viewed in the first direction. In this case, the positional relationship between the output gear 30 and the rotating electric machine 1 may be set so that the outer shape (e.g., circular outer shape portion) of the output member 6 overlaps with the outer shape (e.g., circular outer shape portion) of the rotor shaft 15 when viewed in the first direction. Alternatively, the positional relationship between the output member 6 and the rotor shaft 15 may be set so that the central axis of the output member 6 (i.e., the second axis C2) overlaps with the rotor shaft 15 when viewed in the first direction, or the positional relationship between the output gear 30 and the rotary electric machine 1 may be set so that the central axis of the rotor shaft 15 (i.e., the first axis C1, which is the axis of the rotor shaft 15) overlaps with the pair of output members 6 when viewed in the first direction. By arranging the output gear 30 and the rotary electric machine 1 in such a positional relationship, the influence of the output gear 30 on the overall size of the vehicle drive device 100 in the second direction can be reduced or eliminated. In other words, the overall size of the vehicle drive device 100 in the second direction is substantially determined by the size of the rotary electric machine 1 (and therefore the size of the motor case 21), so that the overall size of the vehicle drive device 100 in the second direction can be minimized under the same size conditions of the rotary electric machine 1.

[0044] Next, with further reference to FIG. 4 and subsequent figures, a characteristic configuration regarding the arrangement of the inverter device 90 according to this embodiment will be described.

[0045] Fig. 4 is a diagram showing a schematic view of the vehicle drive device 100 in an axial direction, showing different portions offset in the axial direction A with a line 400 as a boundary. Fig. 5 is a diagram showing a schematic view of the vehicle drive device 100 in an axial direction as seen from the first axial side A1, with a portion shown in perspective so that the interior can be seen. Fig. 6 is an explanatory diagram of a modification of Fig. 5.

[0046] In this embodiment, the inverter case 24 has an L-shape when viewed in the axial direction, and includes an upper case 241 and a side case 242. The upper case 241 and the side case 242 form a housing space that communicates with each other.

[0047] Specifically, the upper case portion 241 extends in the first direction X and the axial direction A and defines a first inverter accommodating chamber S41 therein. The side case portion 242 extends in the second direction Y and the axial direction A and defines a second inverter accommodating chamber S42 therein. In this case, the inverter case portion 24 extends in the axial direction A around the differential case portion 50 and the first output member 61 (in a manner facing the differential case portion 50 and the first output member 61 in the first direction X and the second direction Y). That is, the inverter case portion 24 forms a peripheral wall portion 250 (a peripheral wall portion relating to a part of the entire circumference around the second axis C2) that extends to surround the differential case portion 50 and the first output member 61 in the output shaft case portion 23. The peripheral wall portion 250 extends in a manner to separate the inverter accommodating chamber S4 from the output shaft accommodating chamber S3. In this case, the peripheral wall portion 250 includes a first wall portion 251 extending in the first direction X and the axial direction A, and a second wall portion 252 extending in the second direction Y and the axial direction A, and the first wall portion 251 and the second wall portion 252 overlap the output gear 30 when viewed in the axial direction. This makes it possible to separate the inverter accommodating chamber S4 from the output shaft accommodating chamber S3 without increasing the physical size of the vehicle drive device 100 as a whole in the first direction X and the second direction Y due to the peripheral wall portion 250.

[0048] The first inverter accommodating chamber S41 and the second inverter accommodating chamber S42 may be in communication with each other and may be perpendicular to each other at a corner between the second side in the first direction X2 and the first side in the second direction Y1. In this case, the inverter case 24 has a corner 249 (see FIG. 4) between the second side in the first direction X2 and the first side in the second direction Y1.

[0049] The first inverter accommodating chamber S41 and the second inverter accommodating chamber S42 overlap in their extending ranges in the axial direction A. For example, the first inverter accommodating chamber S41 and the second inverter accommodating chamber S42 may have substantially the same extending range in the axial direction A. Alternatively, one of the first inverter accommodating chamber S41 and the second inverter accommodating chamber S42 may be set to have a shorter axial extending range than the other.

[0050] The inverter case section 24 is preferably formed so as not to affect the size of the case 2 as a whole in the second direction Y, in order to prevent an increase in the size of the case 2 as a whole. In this embodiment, the size of the case 2 as a whole in the second direction Y is determined by the size of the rotating electric machine 1 in the second direction Y (see lines P0 and P2 in FIGS. 3 and 4), and more specifically, by the size of the motor case section 21 in the second direction Y. Therefore, the inverter case section 24 is disposed closer to the second side Y2 in the second direction than the position of the motor case section 21 closest to the first side Y1 in the second direction (see line P2 in FIGS. 3 and 4). In this case, the size of the case 2 as a whole in the second direction Y can be reduced.

[0051] Furthermore, the upper case portion 241 of the inverter case portion 24 is preferably disposed between both end faces of the case member 200 in the axial direction A. That is, the inverter case portion 24 is preferably disposed between a joint surface (mating surface) 221 between the motor cover member 201 and the case member 200 and a joint surface (mating surface) 222 between the differential cover member 202 and the case member 200 in the axial direction A. In this case, compared to when the inverter case portion 24 is formed to protrude from both end faces of the case member 200 in the axial direction A, it is easier to dispose the inverter case portion 24 on the second direction second side Y2 of the differential cover member 202 than the position closest to the second direction first side Y1. That is, since the second direction second side Y2 of the inverter case portion 24 can be disposed closer to the second direction second side Y2 than the flanges related to the mating surfaces 221 and 222, it is easier to dispose the inverter case portion 24 on the second direction second side Y2 of the differential cover member 202 than the position closest to the second direction first side Y1.

[0052] Furthermore, the inverter case 24 is preferably formed so as not to affect the size of the case 2 as a whole in the first direction X, in order to prevent an increase in the size of the case 2 as a whole. In this embodiment, the boundary (outline) of the size of the case 2 as a whole in the first direction X on the first direction second side X2 is determined by the size of the differential gear mechanism 5, and more specifically, by the size of the transmission mechanism case 22 in the first direction X. Therefore, the inverter case 24 is disposed closer to the first direction first side X1 (the side closer to the rotating electric machine 1) than the position of the transmission mechanism case 22 closest to the first direction second side X2 (the end position of the first direction second side X2; see line P1 in FIGS. 3 and 4 ). In this case, the size of the case 2 as a whole in the first direction X can be reduced.

[0053] In this embodiment, the inverter accommodating chamber S4 may have the first direction second side X2 open in the first direction X, in which case the inverter cover member 203 may extend in the axial direction A and the second direction Y. In this case, the inverter cover member 203 may extend toward the first direction first side X1 (the side closer to the rotating electric machine 1) than the position of the transmission mechanism case portion 22 closest to the first direction second side X2.

[0054] The capacities of the first inverter accommodating chamber S41 and the second inverter accommodating chamber S42 are arbitrary and may be determined depending on the components of the inverter device 90 to be accommodated therein. In this embodiment, as an example, since the size of the rotating electric machine 1 as viewed in the axial direction is larger than the size of the output gear 30, a dead space (a space on the first direction first side X1 that is closer to the position of the transmission mechanism case portion 22 closest to the first direction second side X2 and a space on the second direction second side Y2 that is closer to the position of the motor case portion 21 closest to the second direction first side Y1) is more likely to be formed around the second axis C2 than on the first direction first side X2. Therefore, the dimension (e.g., maximum dimension or average dimension) of the first inverter accommodating chamber S41 in the second direction Y may preferably be set larger than the dimension of the second inverter accommodating chamber S42 in the first direction X. In this case, it becomes easy to position the inverter case portion 24 closer to the second direction second side Y2 than the position closest to the second direction first side Y1 of the motor case portion 21, and closer to the first direction first side X1 (the side closer to the rotating electric machine 1) than the position closest to the first direction second side X2 of the transmission mechanism case portion 22.

[0055] Hereinafter, among the components of the inverter device 90, the components arranged in the upper case portion 241 will be referred to as the first inverter portion 91, and the components arranged in the side case portion 242 will be referred to as the second inverter portion 92. The first inverter portion 91 may preferably include a smoothing capacitor CM, and the second inverter portion 92 may preferably include a power module PM. This arrangement is suitable when the thickness (height) of the required mounting space for the smoothing capacitor CM is greater than that of the power module PM.

[0056] As shown in FIG. 4 , in this embodiment, the rotating electric machine 1 and the first inverter unit 91 or the upper case unit 241 of the inverter device 90 are arranged so that their respective arrangement areas in the vertical direction V overlap. Therefore, as an example, a horizontal direction H perpendicular to the axial direction A (in other words, a direction perpendicular to the axial direction A and the vertical direction V) can be defined as the first direction X. In this case, as shown in FIG. 4 , the second direction Y is parallel to the vertical direction V. As another example, the direction along an imaginary line passing through the first axis C1 and the center of the first inverter unit 91 or the upper case unit 241 in the axial direction can also be defined as the first direction X. Here, the center of the first inverter unit 91 or the upper case unit 241 in the axial direction can be the center of gravity of a figure that forms the outer shape (outer edge) of the first inverter unit 91 or the upper case unit 241 in the axial direction. In the example shown in FIG. 4 , the horizontal direction H perpendicular to the axial direction A and the direction along the imaginary line in the axial direction are parallel to each other. That is, in the example shown in FIG. 4, the first direction X is defined as the same direction in either of the two definitions above.

[0057] 4, the first output member 61 is disposed at a position in the second direction Y where both the rotating electric machine 1 and the inverter device 90 (or the second inverter section 92 or the side case section 242 of the inverter device 90) are disposed, and is sandwiched between the rotating electric machine 1 and the inverter device 90 in the first direction X. The portion of the first output member 61 sandwiched between the rotating electric machine 1 and the inverter device 90 in the first direction X is disposed so that the arrangement area of ​​the rotating electric machine 1 overlaps with the arrangement area of ​​the inverter device 90 in the axial direction A, and the arrangement area of ​​the inverter device 90 overlaps with the arrangement area of ​​the inverter device 90 in the axial direction A (see FIG. 3). As shown in FIG. 4, the output gear 30 may be disposed so as to overlap with both the rotating electric machine 1 and the inverter device 90 in the axial direction. Specifically, the output gear 30 may be disposed so that a portion of the output gear 30 on the first direction first side X1 overlaps with the rotating electric machine 1 in the axial direction, and a portion of the output gear 30 on the first direction second side X2 overlaps with the inverter device 90 in the axial direction. As shown in FIG. 3, the output gear 30 is disposed on one side in the axial direction A (specifically, on the second axial side A2) relative to the rotary electric machine 1 and the inverter device 90.

[0058] In this embodiment, the rotating electric machine 1 and the inverter device 90 may be arranged such that their respective arrangement areas in the axial direction A do not overlap. That is, the inverter device 90 or the inverter case unit 24 may be arranged on the second side X2 in the first direction relative to the rotating electric machine 1. However, the arrangement area of ​​the inverter device 90 or the inverter case unit 24 on a part of the first axial side A1 may overlap with a part of the second axial side A2 of the rotating electric machine 1 in the axial direction A. This also applies to the first direction X. Specifically, the inverter device 90 or the inverter case unit 24 may be arranged on the second side X2 in the first direction relative to the rotating electric machine 1. That is, the inverter device 90 or the inverter case unit 24 may be arranged in an area that overlaps with a part of the transmission mechanism 3 around the second axis C2 (a part of the transmission mechanism 3 excluding the reduction mechanism 34) when viewed in the second direction. However, the inverter device 90 or the inverter case portion 24 may have a placement area in the first direction X that overlaps a portion of the first direction first side X1 with a portion of the first direction second side X2 of the rotating electric machine 1 or the reduction mechanism 34.

[0059] In this embodiment, when the inverter device 90 is mounted on the vehicle, at least a portion (only a portion in the example shown in FIG. 4) of the side case portion 242 of the inverter device 90 is disposed on the side V2 below the second axis C2. Note that when the inverter device 90 is mounted on the vehicle, the entire side case portion 242 of the inverter device 90 may be disposed on the side V1 above the second axis C2, as long as the position of the side case portion 242 of the inverter device 90 in the second direction Y overlaps the position of the first output member 61 in the second direction Y when viewed in the axial direction.

[0060] In this embodiment, the first output member 61 is disposed between the rotating electric machine 1 and the inverter device 90 in the first direction X at a position in the second direction Y where both the rotating electric machine 1 and the inverter device 90 are disposed. Therefore, the arrangement areas in the second direction Y of the rotating electric machine 1, the inverter device 90, and the output gear 30 disposed coaxially with the first output member 61 are overlapped, thereby reducing the overall size of the vehicle drive device 100 in the second direction Y. In this embodiment, the output gear 30 is disposed so as to overlap with both the rotating electric machine 1 and the inverter device 90 in the axial direction. Therefore, while the first output member 61 is configured to be disposed between the rotating electric machine 1 and the inverter device 90 in the first direction X as described above, the space overlapping with the output gear 30 in the axial direction can be effectively utilized, allowing the rotating electric machine 1 and the inverter device 90 to be disposed close to each other in the first direction X. This also reduces the overall size of the vehicle drive device 100 in the first direction X.

[0061] In this way, according to this embodiment, it is possible to reduce the size of the vehicle drive device 100 as a whole in the first direction X and the second direction Y, that is, to reduce the dimensions as viewed in the axial direction of the vehicle drive device 100. This makes it possible to improve the mountability of the vehicle drive device 100 in the vehicle VC.

[0062] In this embodiment, the rotating electric machine 1 and the second inverter section 92 or the side case section 242 of the inverter device 90 are arranged separately on both sides in the first direction of the first output member 61, which is arranged coaxially with the output gear 30. This makes it easier to increase both the degree to which the rotating electric machine 1 overlaps with the output gear 30 in the axial view and the degree to which the second inverter section 92 or the side case section 242 of the inverter device 90 overlaps with the output gear 30 in the axial view, which makes it easier to reduce the dimensions of the vehicle drive device 100 in the axial view.

[0063] Furthermore, according to this embodiment, the inverter case 24 accommodating the inverter device 90 includes the upper case 241 and the side case 242, and therefore the overall capacity (volume of the inverter accommodating chamber S4) can be increased more efficiently than when the inverter case 24 is composed of only the upper case 241 or only the side case 242. This allows for an efficient arrangement (layout) of the inverter device 90 without increasing the overall size of the vehicle drive device 100 in the first direction X and the second direction Y due to the inverter device 90.

[0064] In particular, according to this embodiment, the first inverter unit 91 or the upper case portion 241 of the inverter device 90 extends over a relatively wide range in the first direction X while overlapping the second axis C2 of the first output member 61 when viewed in the second direction. In the illustrated example, the first inverter unit 91 or the upper case portion 241 of the inverter device 90 extends beyond the second axis C2 to the first side X1 in the first direction when viewed in the axial direction. This makes it possible to arrange a first inverter unit 91 having a relatively large size in the first direction X in the first inverter unit 91 or the upper case portion 241. Note that, although the first inverter unit 91 is a smoothing capacitor CM in this embodiment, it may be a power module PM, or may include both the first inverter unit 91 and the smoothing capacitor CM.

[0065] Furthermore, according to this embodiment, various wirings related to the inverter device 90 (for example, bus bar B1 as shown in FIG. 4 ) can be aggregated by utilizing a region (corner region) overlapping a corner 249 of the inverter case 24 in the axial view. Since this region overlapping the corner 249 of the inverter case 24 in the axial view includes a region overlapping the output gear 30 in the axial view, various wirings can be aggregated without increasing the axial size of the vehicle drive device 100. Therefore, connectors and the like may be disposed in the region overlapping the corner 249 of the inverter case 24 in the axial view. The various wirings to be aggregated are arbitrary and may include, for example, high-voltage wiring (power supply wiring) for receiving power from the high-voltage battery BA (see FIG. 1 ) and low-voltage wiring for the control system. Furthermore, some or all of the various wirings disposed in the region overlapping the corner 249 of the inverter case 24 in the axial view may be disposed outside the case 2 (inverter case 24). For example, in the example shown in FIG. 3, the connectors CN10 and CN11 are arranged in an area overlapping a corner 249 of the inverter case 24 in an axial view. In this case, the connector CN10 is arranged on the second axial side A2, and the connector CN11 is arranged on the first axial side A1. The connectors CN10 and CN11 may have their male or female sides fixed to the inverter case 24. The connectors CN10 and CN11 may form a wiring section for electrically connecting a wiring cable (not shown) arranged outside the case 2 to the inverter device 90. One of the connectors CN10 and CN11 may be for high-voltage wiring for receiving power from a high-voltage battery BA (see FIG. 1), and the other may be for low-voltage wiring for a control system. In this case, an appropriate insulation distance can be easily ensured between the connectors CN10 and CN11. In a modified example, one of the connectors CN10 and CN11 may be omitted.

[0066] Furthermore, in this embodiment, the high-voltage connector CN1 (see FIG. 4) for receiving power supply from the battery BA may be disposed on the first side Y1 in the second direction of the reduction mechanism 34. In this case, the connector CN1 can be disposed by utilizing a dead space that is likely to be formed on the first side Y1 in the second direction of the reduction mechanism 34 (a dead space that does not affect the size of the vehicle drive device 100 in the second direction Y). In this case, the high-voltage connector CN1 (see FIG. 4) may be disposed in place of the high-voltage connector of the connectors CN10 and CN11 shown in FIG. 3.

[0067] Incidentally, in the differential gear mechanism 5, the output gear 30 tends to be the largest in terms of size around the second axis C2 among the components of the differential gear mechanism 5. Therefore, when the output gear 30 of the differential gear mechanism 5 is arranged closer to the second axial side A2, the space around the second axis C2 on the first axial side A1 side of the output gear 30 can be secured in a manner that is relatively wide in the radial direction and continuous in the axial direction A, allowing other components (for example, water channels, etc., which will be described later) to be arranged efficiently.

[0068] More specifically, in this embodiment, the output gear 30, the differential case 50, and the first output member 61 are mainly provided around the second axis C2, in this order from the second axial side A2 to the first axial side A1. In this case, the mounting space (mounting space for other members) around the second axis C2 gradually increases from the second axial side A2 to the first axial side A1. That is, the mounting space (mounting space for other members) around the second axis C2 gradually increases from the second axial side A2 to the first axial side A1. Therefore, in this embodiment, the vehicle drive system 100 may have a mount MT (mounting portion) for mounting on the vehicle body VC at a position in the axial direction A of the differential case 50 around the second axis C2. In this case, as shown in FIG. 4, the mount MT may be disposed in an area overlapping the output gear 30 and the inverter device 90 (or the inverter case 24) in the axial view. This allows the mount MT to be efficiently established by utilizing the space that tends to become dead space around the second axis C2. The mount MT may be provided outside the case 2.

[0069] Furthermore, in this embodiment, as described above, the mounting space around the second axis C2 (mounting space for other components) gradually increases from the second axial side A2 toward the first axial side A1. Therefore, the dimension in the second direction Y of the upper case portion 241 of the inverter device 90 (the dimension in the second direction Y of the second inverter accommodating chamber S42) can also gradually increase from the second axial side A2 toward the first axial side A1 without changing the position of the upper case portion 241 closest to the first axial side Y1. In this case, various components of the inverter device 90 may be arranged in the upper case portion 241 such that the dimension in the second direction Y of the components located on the first axial side A1 is smaller than that of the components located on the second axial side A2.

[0070] In this embodiment, the control board of the inverter device 90 may be disposed on the first side Y1 in the second direction of the output gear 30. In this case, the control board may be disposed in a direction normal to the second direction Y. In this case, since the dimension of the control board in the second direction Y is relatively small, it may still be possible to dispose the inverter case portion 24 on the differential cover member 202 closer to the second side Y2 in the second direction than the position closest to the first side Y1 in the second direction.

[0071] Next, the oil lubrication structure and cooling structure of the vehicle drive device 100 of this embodiment will be outlined with reference to FIGS.

[0072] FIG. 6 is a diagram that schematically shows the vehicle drive device 100 in an axial view seen from the first axial side A1, with a portion shown in perspective so that the interior can be seen. FIG. 6 corresponds to a modified example of a water-cooled structure compared to the oil-cooled structure shown in FIG. 5. FIG. 7 is a diagram that schematically shows the interior of the vehicle drive device 100 in an axial view seen from the first axial side A1 (the interior in a cross-sectional view taken along line QQ in FIG. 3), with different portions offset in the axial direction A with line 700 as the boundary. FIG. 7 also schematically shows a water pump W / P. In FIG. 7, the outer periphery of the output gear 30 is shown by a dashed line to explain the positional relationship.

[0073] In this embodiment, the rotating electric machine 1 may be oil-cooled, water-cooled, or a combination thereof. In the oil-cooled type, the inverter accommodation chamber S4 may be sealed so as not to be fluidly connected to the motor accommodation chamber S1, the transmission mechanism accommodation chamber S2, and the output shaft accommodation chamber S3. In this case, as shown in FIG. 5 , a partition wall may not be formed between the motor accommodation chamber S1 and the output shaft accommodation chamber S3, and the compartments may be in communication with each other. In this case, the wiring connection portion 600 between the rotating electric machine 1 and the inverter device 90 may be provided so as to penetrate the partition wall 29 in the axial direction A that separates the motor accommodation chamber S1 or the output shaft accommodation chamber S3 from the inverter accommodation chamber S4. The wiring connection portion 600 may be in the form of a high-voltage connector or terminal block for connecting the rotating electric machine 1 and the power module PM of the inverter device 90. The wiring connection portion 600 may be arranged in a region overlapping the output gear 30 when viewed in the axial direction.

[0074] On the other hand, in the case of a water-cooled inverter, the inverter accommodating chamber S4 may be fluidly connected to the motor accommodating chamber S1, etc. In this case, for example, as shown in FIG. 6, a part or all of the wall (such as the partition wall 29 in FIG. 5) separating the inverter accommodating chamber S4 and the motor accommodating chamber S1 may be eliminated, facilitating the routing of wires between the rotating electric machine 1 and the inverter device 90. For example, in the example shown in FIG. 6, a wire connection portion 600 between the rotating electric machine 1 and the inverter device 90 is provided in a manner that communicates with both the inverter accommodating chamber S4 and the motor accommodating chamber S1. In this case, a partition wall 28 may be formed between the motor accommodating chamber S1 and the output shaft accommodating chamber S3, as shown in FIG.

[0075] If the rotating electric machine 1 is a water-cooled type, a cooling water passage (hereinafter referred to as a "motor cooling water passage 129" for the sake of distinction) may be formed around the outer periphery of the stator core 12. In this case, the motor cooling water passage 129 may be formed in the case member 200, or may be formed in a separate support member 204 (a component of the motor case portion 21 of the case 2) connected to the case member 200. In this case, the separate support member 204 may be cylindrical and made of a material with high thermal conductivity, such as aluminum, and may be integrated with the radially outer side of the stator core 12 by shrink fitting, casting, or the like. This reduces thermal resistance between the support member 204 and the stator core 12, allowing the coils and the like to be efficiently cooled via the stator core 12. In this case, the separate support member 204 may be integrated with the case member 200 by fastening, or the like. If the rotor shaft 15 is hollow and has an axial hole, the motor cooling water passage 129 may be connected to the axial hole of the rotor shaft 15.

[0076] In this embodiment, the inverter case portion 24 of the case 2 has a cooling water passage (hereinafter referred to as the "inverter cooling water passage 99" for the sake of distinction) through which cooling water (e.g., cooling water containing long-life coolant) that cools the inverter device 90 passes.

[0077] The inverter cooling water passage 99 may be arranged in a region that overlaps with the output gear 30 when viewed in the axial direction. In this case, the inverter cooling water passage 99 can be efficiently arranged (layout) without increasing the overall size of the vehicle drive device 100 in the first direction X and the second direction Y due to the inverter cooling water passage 99.

[0078] When the smoothing capacitor CM of the inverter device 90 is disposed in the upper case portion 241, the inverter cooling water passage 99 may have a water passage portion (hereinafter also referred to as the "upper water passage portion") (not shown) that extends to an area that overlaps with all or part of the smoothing capacitor CM when viewed in the second direction. In this case, the upper water passage portion may be disposed on the second side Y2 in the second direction relative to the smoothing capacitor CM. Also, in this case, the upper water passage portion may be formed in the first wall portion 251 of the peripheral wall portion 250 described above.

[0079] When the power module PM of the inverter device 90 is disposed in the side case portion 242, the inverter cooling water channel 99 may have a water channel portion (hereinafter also referred to as a "side water channel portion 9902") that extends in an area that overlaps with all or part of the power module PM when viewed in the first direction. In this case, the side water channel portion 9902 may be disposed on the first side X1 in the first direction relative to the power module PM. Also, in this case, the side water channel portion 9902 may be formed in the second wall portion 252 of the peripheral wall portion 250 described above. Note that the power module PM may have a plurality of fins F formed on a surface of the housing on the first side X1 in the first direction (a surface that comes into contact with the cooling water in the inverter cooling water channel 99).

[0080] Furthermore, when the power module PM of the inverter device 90 is disposed in the side case portion 242, the side water channel portion 9902 may extend in the second direction Y together with the power module PM from a second direction second side Y2 of the central axis of the first output member 61 (i.e., the second axis C2) to a second direction first side Y1 of the central axis (i.e., the second axis C2). Here, the separation distance in the first direction X between the side case portion 242 extending in the axial direction A and the second direction Y and the differential case portion 50 is smallest at a position overlapping with the central axis of the differential case portion 50 (i.e., the second axis C2) as viewed in the first direction, and increases with increasing distance from the overlapping position toward the second direction first side Y1 or the second direction second side Y2. Taking advantage of this, the side water passage portion 9902 of the inverter cooling water passage 99 may have an inlet portion 991 and a chamber portion 992 in a region where the distance from the differential case portion 50 in the first direction X is relatively large (for example, a region on the second side Y2 in the second direction relative to the first output member 61 when viewed in the axial direction). The inlet portion 991 is a portion into which the cooling water discharged from the water pump W / P (see FIG. 7) is introduced. Note that, hereinafter, the terms "upstream side" and "downstream side" are used with reference to the flow of the cooling water.

[0081] The chamber portion 992 may extend axially over the entire axial direction A of the side water channel portion 9902 of the inverter cooling water channel 99. The chamber portion 992 has a cross-sectional area significantly larger than that of the inlet portion 991, and a resistance significantly smaller than that of the flow channel portion in contact with the power module PM (for example, the flow channel around the fins F). Note that the cross-sectional area of ​​the inverter cooling water channel 99 at each position along the second direction is the cross-sectional area when cut by a plane perpendicular to the flow direction, and in this case corresponds to the cross-sectional area when cut by a plane perpendicular to the second direction.

[0082] Therefore, by providing such chamber portion 992 adjacent to the inlet portion 991 on the downstream side, it is possible to effectively ensure the necessary flow rate of the cooling water introduced into the inverter cooling water passage 99. Note that a chamber room 993 similar to the chamber portion 992 may be provided downstream of the flow path portion in contact with the power module PM in the side water passage portion 9902 of the inverter cooling water passage 99.

[0083] Furthermore, when the above-described motor cooling water passage 129 is provided, the inverter cooling water passage 99 may be connected to the motor cooling water passage 129. In this case, the inverter cooling water passage 99 may be arranged upstream of the motor cooling water passage 129, and in this case, the motor cooling water passage 129 may have an outlet portion (not shown) for returning the cooling water to the water pump W / P. The outlet portion (not shown), together with the above-described inlet portion 991, may be arranged in a region overlapping with the output gear 30 in the axial view. In this case, the inverter cooling water passage 99 can be efficiently arranged without increasing the size of the vehicle drive device 100 as a whole in the first direction X and the second direction Y due to the inverter cooling water passage 99.

[0084] Furthermore, when the above-described motor cooling water passage 129 is provided, a water passage for connecting the inverter cooling water passage 99 and the motor cooling water passage 129 (hereinafter also referred to as the "connecting water passage 1290") may be formed in the case 2. That is, the connecting water passage 1290 may be realized as a water passage within the case, similar to the motor cooling water passage 129 and the inverter cooling water passage 99. The connecting water passage 1290 may extend in the axial direction A and the first direction X. Alternatively, the connecting water passage 1290 may extend in the axial direction A, the first direction X, and the second direction Y. In this case, the connecting water passage 1290 may be formed in a portion of the case 2 that forms the motor case portion 21 and the transmission mechanism case portion 22 or the output shaft case portion 23. Furthermore, the connecting water passage 1290 may be disposed above the first output member 61 in the axial view and in a region that overlaps with the output gear 30 in the axial view.

[0085] Next, a vehicle driving device 100A according to a second embodiment will be described with reference to Figure 8 onwards. In the following description of the second embodiment and the associated drawings, components that may be substantially similar to those in the first embodiment described above will be given the same reference numerals and descriptions thereof may be omitted.

[0086] Fig. 8 is a two-sided view that schematically shows the vehicle driving device 100A according to this embodiment, Fig. 9 is a view that schematically shows the vehicle driving device 100A as viewed in a direction perpendicular to the two directions of the two-sided view of Fig. 8 (i.e., as viewed in a first direction), and Fig. 10 is an explanatory diagram of a modified example of Fig. 9. Figs. 9 and 10 show different portions that are offset in the first direction X with a line 802 as a boundary.

[0087] The vehicle driving device 100A according to the second embodiment differs from the vehicle driving device 100 according to the first embodiment described above mainly in the arrangement of the inverter device and the inverter case unit, etc. Specifically, the vehicle driving device 100A according to the second embodiment differs from the vehicle driving device 100 according to the first embodiment described above in that the case 2 and the inverter device 90 are replaced with a case 2A and an inverter device 90A, respectively.

[0088] Case 2A differs from Case 2 according to the first embodiment in that the inverter case 24 is replaced with an inverter case 24A.

[0089] In this embodiment, the inverter case portion 24A differs from the inverter case portion 24 of the first embodiment described above (which has an L-shaped configuration when viewed in the axial direction) in that it extends only toward the first side Y1 in the second direction beyond the first output member 61 when viewed in the axial direction.

[0090] Specifically, the inverter case portion 24A extends in the first direction X and the axial direction A and defines an inverter accommodating chamber S4 therein. In this case, as shown in FIGS. 8 and 9 , the inverter case portion 24A extends in the axial direction A in a manner facing the differential gear case portion 50 and the first output member 61 in the second direction Y. That is, the inverter case portion 24A extends so as to cover the second direction first side Y1 of the differential gear case portion 50 in the transmission mechanism case portion 22 and the second direction first side Y1 of the first output member 61 in the output shaft case portion 23. In this way, the inverter case portion 24A extends in the first direction X and the axial direction A and overlaps the output gear 30 when viewed in the axial direction.

[0091] The inverter case section 24A is preferably formed so as not to affect the size of the case 2A as a whole in the second direction Y, in order to prevent an increase in the size of the case 2A as a whole. In this embodiment, the size of the case 2A as a whole in the second direction Y is determined by the size of the rotating electric machine 1 in the second direction Y, and more specifically, by the size of the motor case section 21 in the second direction Y. Therefore, the inverter case section 24A is disposed closer to the second side Y2 in the second direction than the position of the motor case section 21 closest to the first side Y1 in the second direction (see line P2 in FIG. 8). In this case, the size of the case 2A as a whole in the second direction Y can be reduced.

[0092] Moreover, the inverter case portion 24A is preferably disposed between both end faces of the case member 200 in the axial direction A. That is, the inverter case portion 24A is preferably disposed between a joint surface (mating surface) 221 between the motor cover member 201 and the case member 200 and a joint surface (mating surface) 222 between the differential cover member 202 and the case member 200 in the axial direction A. In this case, compared to when the inverter case portion is formed to protrude from both end faces of the case member 200 in the axial direction A, it is easier to dispose the inverter case portion 24A on the differential cover member 202 closer to the second direction second side Y2 than the position on the second direction first side Y1. That is, because the inverter case portion 24A can be extended below the flanges associated with the mating surfaces 221 and 222, it is easier to dispose the inverter case portion 24A on the differential cover member 202 closer to the second direction second side Y2 than the position on the second direction first side Y1.

[0093] Furthermore, the inverter case 24A is preferably formed so as not to affect the overall size of the case 2A in the first direction X, in order to prevent an increase in the overall size of the case 2A. In this embodiment, the boundary (outline) of the overall size of the case 2A in the first direction X on the first direction second side X2 is determined by the size of the differential gear mechanism 5, specifically, by the size of the transmission mechanism case 22 in the first direction X. Therefore, the inverter case 24A or the inverter device 90A is disposed closer to the first direction first side X1 (the side closer to the rotating electric machine 1) than the closest position on the first direction second side X2 of the transmission mechanism case 22 (the end position on the first direction second side X2, see line P1 in FIG. 8 ). In this case, the overall size of the case 2A in the first direction X can be reduced.

[0094] In a modified example, a part of the inverter case 24A or a part of the inverter device 90A may protrude toward the first direction second side X2 from the position closest to the first direction second side X2 (the end position of the first direction second side X2) of the transmission mechanism case 22. In this case, however, by arranging the relatively large power module PM and smoothing capacitor CM, among the various components of the inverter device 90A, closer to the first direction first side X1 (the side closer to the rotating electric machine 1) than the position closest to the first direction second side X2 of the transmission mechanism case 22 (the end position of the first direction second side X2), it is possible to minimize an increase in the physical size caused by the protruding part.

[0095] As shown in FIG. 8 , in this embodiment, the rotating electric machine 1 and the inverter device 90A or the inverter case unit 24A are also arranged so that their respective arrangement areas in the vertical direction V overlap. Therefore, as an example, the horizontal direction H perpendicular to the axial direction A (in other words, the direction perpendicular to the axial direction A and the vertical direction V) can be defined as the first direction X. In this case, as shown in FIG. 8 , the second direction Y is parallel to the vertical direction V. As another example, the direction along an imaginary line passing through the first axis C1 and the center of the first inverter unit 91 or the inverter case unit 24A in the axial direction can also be defined as the first direction X. Here, the center of the first inverter unit 91 or the inverter case unit 24A in the axial direction can be the center of gravity of a figure that forms the outer shape (outer edge) of the first inverter unit 91 or the inverter case unit 24A in the axial direction. In the example shown in FIG. 8 , the horizontal direction H perpendicular to the axial direction A and the direction along the imaginary line in the axial direction are parallel to each other. That is, in the example shown in FIG. 8, the first direction X is defined as the same direction in either of the two definitions above.

[0096] 8, the output gear 30 is arranged so as to overlap with both the rotating electric machine 1 and the inverter device 90A in the axial direction. Specifically, the output gear 30 is arranged so that a portion of the output gear 30 on a first direction first side X1 overlaps with the rotating electric machine 1 in the axial direction, and a portion of the output gear 30 on a second direction first side Y1 overlaps with the inverter device 90A in the axial direction. As shown in FIG. 8, the output gear 30 is arranged on one side in the axial direction A (specifically, on a second axial side A2) of the rotating electric machine 1 and the inverter device 90A. The rotating electric machine 1 and the inverter device 90A may be arranged so that their arrangement regions in the axial direction A overlap.

[0097] In this embodiment, the inverter device 90A or the inverter case unit 24A may be arranged on the second side X2 in the first direction relative to the rotating electric machine 1. That is, the inverter device 90A or the inverter case unit 24A may be arranged in a region that overlaps with a portion of the transmission mechanism 3 around the second axis C2 (a portion of the transmission mechanism 3 excluding the reduction mechanism 34) when viewed in the second direction. However, a portion of the first side X1 in the first direction of the inverter device 90A or the inverter case unit 24A may overlap with a portion of the second side X2 in the first direction of the rotating electric machine 1 or the reduction mechanism 34 in the arrangement region in the first direction X.

[0098] According to this embodiment, the respective arrangement areas of the rotating electric machine 1, the inverter device 90A, and the output gear 30 arranged coaxially with the first output member 61 overlap in the axial view, thereby making it possible to reduce the size of the vehicle drive device 100 as a whole in the second direction Y. That is, by effectively utilizing the space overlapping with the output gear 30 in the axial view, the rotating electric machine 1 and the inverter device 90A can be arranged close to each other in the first direction X. This also makes it possible to reduce the size of the vehicle drive device 100 as a whole in the first direction X. Furthermore, by arranging the rotating electric machine 1 and the inverter device 90A close to each other in the first direction X, it becomes easier to arrange wiring for electrical connection between the rotating electric machine 1 and the inverter device 90A.

[0099] In this way, according to this embodiment, it is possible to reduce the size of the vehicle drive device 100 as a whole in the first direction X and the second direction Y, that is, to reduce the dimensions as viewed in the axial direction of the vehicle drive device 100. This makes it possible to improve the mountability of the vehicle drive device 100 in the vehicle VC.

[0100] In this embodiment, as described above, the mounting space around the second axis C2 (the mounting space for other components) gradually increases from the second axial side A2 toward the first axial side A1. Therefore, the dimension in the second direction Y of the inverter case section 24A of the inverter device 90A (the dimension in the second direction Y of the second inverter accommodating chamber S42) can also gradually increase from the second axial side A2 toward the first axial side A1, as shown in FIG. 9 , without changing the position of the inverter case section 24A closest to the first axial side Y1. In this case, various components of the inverter device 90A may be arranged in the inverter case section 24A such that the dimension in the second direction Y of the components located on the first axial side A1 is smaller than that of the components located on the second axial side A2.

[0101] 9, the inverter case 24A has a differential-side case 241A that overlaps with the differential case 50 when viewed in the second direction, and an intermediate-side case 242A that overlaps with the first output member 61 when viewed in the second direction, and the intermediate-side case 242A may be set to have a larger dimension in the second direction Y than the differential-side case 241A. In this case, various components of the inverter device 90A that may have significant differences in dimension in the second direction Y can be efficiently arranged. The differential-side case 241A and the intermediate-side case 242A may be internally connected.

[0102] In this embodiment, as a preferred example, as shown in Fig. 9, the power module PM is arranged in the differential-side case portion 241A, and the smoothing capacitor CM is arranged in the intermediate-side case portion 242A. Such an arrangement is suitable when the smoothing capacitor CM requires a larger mounting space (height) than the power module PM. In the example shown in Fig. 8, the inverter case portion 24A is provided with a bus bar B2 extending in the axial direction A on the first side X1 in the first direction of the power module PM and the smoothing capacitor CM.

[0103] In this embodiment, a high-voltage connector (not shown) for receiving power supply from the battery BA (see FIG. 1 ) may be disposed on the second direction first side Y1 of the reduction gear mechanism 34. In this case, the connector CN1 can be disposed by utilizing a dead space that is likely to be formed on the second direction first side Y1 of the reduction gear mechanism 34 (a dead space that does not affect the size of the vehicle drive device 100 in the second direction Y). Alternatively, the high-voltage connector may be disposed on the first direction second side X2 with respect to the power module PM or the smoothing capacitor CM together with some of the components of the inverter device 90A (relatively small components other than the power module PM or the smoothing capacitor CM, such as a filter). In this case, these components may protrude toward the first direction second side X2 beyond the position of the transmission mechanism case 22 closest to the first direction second side X2 (the end position of the first direction second side X2).

[0104] 10, the control board SB of the inverter device 90A may be disposed on the first side Y1 in the second direction of the output gear 30. That is, the control board SB may be disposed on the first side Y1 in the second direction of the output gear 30 so as to overlap with the output gear 30 when viewed in the second direction. In this case, the control board SB may be disposed in an orientation in which the second direction Y is the normal direction. In this case, since the dimension of the control board SB in the second direction Y is relatively small, it may still be possible to dispose the inverter case portion 24A (inverter cover member 203A) on the differential cover member 202 closer to the second side Y2 in the second direction than the position closest to the first side Y1 in the second direction.

[0105] Next, the oil lubrication structure and cooling structure of the vehicle drive device 100 of this embodiment will be outlined with reference to FIGS.

[0106] Fig. 11 is a diagram showing the vehicle driving device 100A in an axial direction as seen from the first axial side A1, with a portion shown in perspective so that the interior can be seen. Fig. 12 is a diagram showing the interior of the vehicle driving device 100A in an axial direction as seen from the first axial side A1, with different portions offset in the axial direction A with line 800 as the boundary. In Fig. 12, the outer periphery of the output gear 30 is shown with a dashed line to explain the positional relationship.

[0107] In this embodiment, the rotating electric machine 1 may be oil-cooled, water-cooled, or a combination thereof. In the case of an oil-cooled type, the inverter accommodating chamber S4 may be sealed so as not to be fluidly connected to the motor accommodating chamber S1, the transmission mechanism accommodating chamber S2, and the output shaft accommodating chamber S3. In this case, a partition wall may not be formed between the motor accommodating chamber S1 and the output shaft accommodating chamber S3, and the motor accommodating chamber S1 and the output shaft accommodating chamber S3 may be connected to each other. In this case, the wiring connection portion 600 between the rotating electric machine 1 and the inverter device 90A may be provided so as to penetrate a partition wall (not shown) in the axial direction A that separates the motor accommodating chamber S1 or the output shaft accommodating chamber S3 from the inverter accommodating chamber S4. The wiring connection portion 600 may be in the form of a high-voltage connector or terminal block for connecting the rotating electric machine 1 and the power module PM of the inverter device 90A.

[0108] On the other hand, if the inverter accommodating chamber S4 is water-cooled, the inverter accommodating chamber S4 may be fluidly connected to the motor accommodating chamber S1, etc. In this case, for example, as shown in FIG. 6, part or all of the wall separating the inverter accommodating chamber S4 and the motor accommodating chamber S1 may be eliminated, facilitating the routing of wires between the rotating electric machine 1 and the inverter device 90A. For example, in the example shown in FIGS. 11 and 12, the rotating electric machine 1 is water-cooled, and a wire connection portion 600 between the rotating electric machine 1 and the inverter device 90A is provided in a manner that communicates with both the inverter accommodating chamber S4 and the motor accommodating chamber S1. In this case, a partition wall 28 may be formed between the motor accommodating chamber S1 and the output shaft accommodating chamber S3, as shown in FIG.

[0109] 11 and 12, a cooling water passage (hereinafter referred to as "motor cooling water passage 129A" ​​for the sake of distinction) is formed around the outer periphery of stator core 12. In this case, motor cooling water passage 129A may be formed in case member 200, or may be formed in a separate support member 204A (a component of motor case portion 21 of case 2A) joined to case member 200. In this case, support member 204A may be cylindrical and may be integrated with the radially outer side of stator core 12 by shrink fitting, casting, or the like. In this case, support member 204A may be integrated with case member 200 by fastening, or the like. In addition, if rotor shaft 15 is hollow and has an axial hole, motor cooling water passage 129A may be in communication with the axial hole of rotor shaft 15.

[0110] In this embodiment, the inverter case portion 24A of the case 2A has a cooling water passage (hereinafter referred to as "inverter cooling water passage 99A" for the sake of distinction) through which coolant for cooling the inverter device 90A passes.

[0111] The inverter cooling water passage 99A may be arranged in a region that overlaps with the output gear 30 when viewed in the axial direction. In this case, an efficient arrangement (layout) of the inverter cooling water passage 99A can be achieved without increasing the overall size of the vehicle drive device 100 in the first direction X and the second direction Y due to the inverter cooling water passage 99A.

[0112] The inverter cooling water passage 99A may have a water passage portion extending into an area that entirely or partially overlaps with the smoothing capacitor CM when viewed in the second direction, but preferably may extend into an area that entirely or partially overlaps with the power module PM when viewed in the second direction without having a water passage portion extending into an area that entirely or partially overlaps with the smoothing capacitor CM when viewed in the second direction. That is, the inverter cooling water passage 99A may be located on the second axial side A2 of the smoothing capacitor CM. In this case, the inverter cooling water passage 99A may be formed in the partition wall portion 28 of the case 2A that separates the inverter accommodating chamber S4 and the transmission mechanism accommodating chamber S2.

[0113] In this embodiment, the smoothing capacitor CM is disposed in a region overlapping with the first output member 61 as viewed in the second direction, and is disposed relatively far from the rotating electric machine 1, which is the main heat source other than the heat source inside the inverter case portion 24A. Therefore, even if the inverter cooling water passage 99A is disposed so as not to overlap with the smoothing capacitor CM as viewed in the second direction, the smoothing capacitor CM can be appropriately cooled via the inverter case portion 24A, which is cooled by the coolant in the inverter cooling water passage 99A. Therefore, such an arrangement in which the inverter cooling water passage 99A does not overlap with the smoothing capacitor CM as viewed in the second direction allows for an efficient arrangement of the inverter cooling water passage 99A without significantly reducing the cooling performance of the smoothing capacitor CM.

[0114] The inverter cooling water passage 99A may have an inlet portion 991A and a chamber portion 992A in a region where the distance from the differential case portion 50 in the first direction X is relatively large (for example, a region on the second side Y2 in the second direction relative to the first output member 61 when viewed in the axial direction). The inlet portion 991A is a portion into which cooling water discharged from a water pump (not shown) (see water pump W / P in FIG. 7) is introduced.

[0115] The chamber portion 992A may extend axially over the entire length of the inverter cooling water passage 99A in the axial direction A. The chamber portion 992A has a cross-sectional area (and volume) significantly larger than that of the inlet portion 991A, and has significantly smaller resistance than the flow path portion in contact with the power module PM (e.g., the flow path around the fins). Therefore, by providing the chamber portion 992A adjacent to the inlet portion 991A from the downstream side, the required flow rate of the cooling water introduced into the inverter cooling water passage 99A can be effectively ensured. Note that a chamber chamber 993A similar to the chamber portion 992A may be provided downstream of the flow path portion in the inverter cooling water passage 99A that is in contact with the power module PM.

[0116] Furthermore, when the above-described motor cooling water passage 129A is provided, the inverter cooling water passage 99A may be connected to the motor cooling water passage 129A. In this case, the inverter cooling water passage 99A may be arranged upstream of the motor cooling water passage 129A, and in this case, the motor cooling water passage 129A may have an outlet portion (not shown) for returning cooling water to a water pump (not shown). The outlet portion (not shown), together with the above-described inlet portion 991A, may be arranged in a region overlapping with the output gear 30 in an axial view. In this case, the inverter cooling water passage 99A can be efficiently arranged without increasing the size of the vehicle drive device 100 as a whole in the first direction X and the second direction Y due to the inverter cooling water passage 99A.

[0117] Furthermore, when the above-described motor cooling water passage 129A is provided, a water passage for connecting the inverter cooling water passage 99A and the motor cooling water passage 129A (hereinafter also referred to as the "connecting water passage 1290A") may be formed in the case 2A. That is, the connecting water passage 1290A may be realized as a water passage within the case, similar to the motor cooling water passage 129A and the inverter cooling water passage 99A. The connecting water passage 1290A may extend in the axial direction A and the first direction X. Alternatively, the connecting water passage 1290A may extend in the axial direction A, the first direction X, and the second direction Y. In this case, the connecting water passage 1290A may be formed in a portion of the case 2A that forms the motor case portion 21 and the transmission mechanism case portion 22 or the output shaft case portion 23. Furthermore, the connecting water passage 1290A may be disposed above the first output member 61 in the axial view and in a region that overlaps with the output gear 30 in the axial view.

[0118] Although each embodiment has been described in detail above, it is not limited to a specific embodiment, and various modifications and changes are possible within the scope of the claims. It is also possible to combine all or a plurality of components of the above-described embodiments. Furthermore, among the effects of each embodiment, the effects related to the dependent claims are additional effects that are distinct from the generic concept (independent claim).

[0119] For example, in the first embodiment described above, the first output member 61 is disposed between the rotating electric machine 1 and the inverter device 90 in the first direction X at a position in the second direction Y where both the rotating electric machine 1 and the inverter device 90 are disposed. However, this is not limited to this. For example, the inverter device 90 may be disposed on the second axial side A2 of the first output member 61. In this case, the differential case 50 may be disposed between the rotating electric machine 1 or the reduction mechanism 34 and the inverter device 90 in the first direction X at a position in the second direction Y where both the rotating electric machine 1 or the reduction mechanism 34 and the inverter device 90 are disposed. Note that even in such a case, the first output member 61 may be disposed between the rotating electric machine 1 and the inverter device 90 in the first direction X at a position in the second direction Y where both the rotating electric machine 1 and the inverter device 90 are located, as viewed in the axial direction.

[0120] Furthermore, in the above-described first embodiment (and also in the second embodiment), the inverter case section 24 extends in the axial direction A around the differential case section 50 and the first output member 61 (in a manner facing the differential case section 50 and the first output member 61 in the first direction X and the second direction Y), but this is not limited to this. For example, in the above-described first embodiment, the inverter case section 24 may extend in the axial direction A around the differential case section 50 of the differential case section 50 and the first output member 61 (in a manner facing the differential case section 50 in the first direction X and the second direction Y). Furthermore, in the above-described second embodiment, the inverter case section 24A may extend in the axial direction A around the differential case section 50 of the differential case section 50 and the first output member 61 (in a manner facing the differential case section 50 in the second direction Y). Furthermore, the following notes are disclosed regarding the above embodiment. [Appendix 1] a rotating electric machine having a rotor and a stator; a first output member that is one of a pair of output members that are drivingly connected to the pair of wheels, respectively; a transmission mechanism that transmits a driving force between the rotary electric machine and the pair of output members; an inverter device that receives power from a battery and supplies power to the rotating electric machine; a case having a first case portion that houses the rotating electric machine, a second case portion that houses the transmission mechanism, and a third case portion that houses the inverter device; a rotor shaft to which the rotor is fixed so as not to rotate and which is supported by the case, The rotating electric machine and the pair of output members are arranged on two parallel shafts, the transmission mechanism includes an output gear drivingly connected to at least one of the pair of output members, the output gear being coaxial with the pair of output members; the output gear is disposed so as to overlap with each of the rotating electric machine and the inverter device when viewed in the axial direction, the inverter device is disposed so as to overlap with the transmission mechanism or the first output member when viewed in the up-down direction, A vehicle drive device, wherein the pair of output members are arranged so as to overlap with the axis of the rotor shaft when viewed in the direction along the vehicle fore-and-aft direction, and the inverter device is arranged below the uppermost position of the first case portion in the vertical direction. [Appendix 2] a rotating electric machine having a rotor and a stator; a first output member that is one of a pair of output members that are drivingly connected to the pair of wheels, respectively; a transmission mechanism that transmits a driving force between the rotary electric machine and the pair of output members; an inverter device that receives power from a battery and supplies power to the rotating electric machine; a case having a first case portion that houses the rotating electric machine, a second case portion that houses the transmission mechanism, and a third case portion that houses the inverter device; a rotor shaft to which the rotor is fixed so as not to rotate and which is supported by the case, The rotating electric machine and the pair of output members are arranged on two parallel shafts, the transmission mechanism includes an output gear drivingly connected to at least one of the pair of output members, the output gear being coaxial with the pair of output members; the output gear is disposed so as to overlap with each of the rotating electric machine and the inverter device when viewed in the axial direction, the inverter device is disposed so as to overlap with the transmission mechanism or the first output member when viewed in the up-down direction, the inverter device includes a power module and a smoothing capacitor; the power module and the smoothing capacitor are arranged side by side along the axial direction, the transmission mechanism includes a differential gear mechanism, the differential gear mechanism includes a differential case portion that rotates integrally with the output gear, and a first side gear that is drivingly connected to the first output member, The vehicle drive device, wherein the power module overlaps with the differential case when viewed in the up-down direction, and the smoothing capacitor overlaps with the first output member when viewed in the up-down direction. [Appendix 3] The case further accommodates the first output member. 3. The vehicle drive device according to claim 1, wherein a first housing chamber in the case that houses the rotating electric machine communicates with a second housing chamber in the case that houses the first output member. [Appendix 4] The vehicle drive device described in Appendix 1 or 2, wherein the inverter device is arranged closer to the rotating electric machine than the end position of the second case portion opposite the rotating electric machine in the fore-and-aft direction of the vehicle. [Appendix 5] A vehicle drive device as described in Appendix 1, wherein a third housing chamber in the case that houses the inverter device extends in the vehicle fore-and-aft direction and in the axial direction, with an area closer to the rotating electric machine in the axial direction having a larger vertical dimension than an area farther from the rotating electric machine in the axial direction. [Appendix 6] the inverter device includes a power module and a smoothing capacitor; 6. The vehicle drive device according to claim 5, wherein the smoothing capacitor is arranged closer to the rotating electric machine in the axial direction than the power module. [Appendix 7] A vehicle drive device as described in Appendix 2, wherein a third housing chamber in the case that houses the inverter device extends in the vehicle fore-and-aft direction and in the axial direction, with an area closer to the rotating electric machine in the axial direction having a larger vertical dimension than an area farther from the rotating electric machine in the axial direction. [Appendix 8] 8. The vehicle drive device according to claim 7, wherein the smoothing capacitor is arranged closer to the rotating electric machine in the axial direction than the power module. [Appendix 9] The inverter device further includes a control board. 3. The vehicle drive device according to claim 1, wherein the control board overlaps with the output gear when viewed in the up-down direction. [Appendix 10] the inverter device includes a power module, the case is formed with a first cooling water passage through which cooling water for cooling the rotating electric machine flows, and a second cooling water passage that is in communication with the first cooling water passage and extends to a region that overlaps with the power module when viewed in a vertical direction; 2. The vehicle drive device according to claim 1, wherein the second cooling water passage overlaps with the output gear when viewed in the axial direction. [Appendix 11] the case is formed with a first cooling water passage through which cooling water for cooling the rotating electric machine flows, and a second cooling water passage that is in communication with the first cooling water passage and extends to a region that overlaps with the power module when viewed in a vertical direction; 3. The vehicle drive device according to claim 2, wherein the second cooling water passage overlaps with the output gear when viewed in the axial direction. [Appendix 12] the first case portion is disposed on one side in the axial direction with respect to the second case portion, the first case portion has a first cover member that covers the opening on the one side in the axial direction, the second case portion has a second cover member that covers an opening on the opposite side to the one side in the axial direction, 3. The vehicle drive device according to claim 1, wherein the inverter device extends between the first case portion and the second cover member in the axial direction. [Appendix 13] The vehicle drive device according to any one of appendixes 1 to 9, wherein the uppermost position and the lowermost position of the case are located in the first case portion. [Explanation of symbols]

[0121] REFERENCE SIGNS LIST 1 Rotating electric machine, 3 Transmission mechanism, 5 Differential gear mechanism, 50 Differential case portion, 51 First side gear, 15 Rotor shaft, 2, 2A Case, 21 Motor case portion (first case portion), 22 Transmission mechanism case portion (second case portion), 23 Output shaft case portion, 24, 24A Inverter case portion (third case portion), 201 Motor cover member (first cover member), 202 Differential cover member (second cover member), 6 Output member, 61 First output member, 30 Output gear, 90, 90A... Inverter device, 99, 99A... Inverter cooling water passage (second cooling water passage), 129, 129A... Motor cooling water passage (first cooling water passage), S1... Motor housing (first housing), S3... Output shaft housing (second housing), S4... Inverter housing (third housing), C1... First shaft (shaft), C2... Second shaft (shaft), BA... Battery, A... Axial direction, X... First direction, Y... Second direction, PM... Power module, CM... Smoothing capacitor, SB... Control board

Claims

1. A rotating electric machine, an output member drivingly connected to the wheels; a transmission mechanism that transmits a driving force between the rotating electric machine and the output member; a control system electrically connected to the rotating electric machine; a case having a first case portion that houses the rotating electric machine, a second case portion that houses the transmission mechanism, and a third case portion that houses the control system, The rotating electric machine and the output member are arranged on two separate shafts, the transmission mechanism includes an output gear drivingly connected to the output member, a rotational axis of the rotary electric machine and a rotational axis of the output gear are separated into two parallel shafts, the output gear is arranged to overlap with the control system when viewed in the axial direction; The control system is arranged so as to overlap with a rotation axis of the output gear when viewed in the up-down direction. Vehicle drive unit.

2. A vehicle drive device as described in claim 1, wherein the vertical position range of the control system includes the vertical position of the rotational axis of the rotating electric machine.

3. A vehicle drive device as described in claim 2, wherein the vertical position range of the control system further includes the vertical position of the rotational axis of the output gear.

4. A rotating electric machine, a transmission mechanism that transmits a driving force of the rotating electric machine; a control system electrically connected to the rotating electric machine; a case having a first case portion that houses the rotating electric machine, a second case portion that houses the transmission mechanism, and a third case portion that houses the control system, the transmission mechanism includes an output gear drivingly connected to a wheel; a rotational axis of the rotary electric machine and a rotational axis of the output gear are arranged on two separate shafts that are not coaxial; a vertical positional range of the third case portion includes a vertical position of a rotation axis of the rotating electric machine, the vertical positional range of the third case portion further includes the vertical position of the rotation axis of the output gear, The vehicle drive device, wherein the third case portion is disposed so as to overlap with a rotation axis of the output gear when viewed in the up-down direction.

5. A vehicle drive device as described in Claim 4, wherein the output gear is arranged so as to overlap at least one of the rotating electric machine and the third case portion when viewed in the axial direction.

6. A vehicle drive device described in any one of claims 1 to 5, wherein the third case portion and the first case portion or the second case portion are formed integrally while being separated from each other by a partition portion.

7. A vehicle drive device described in any one of claims 1 to 6, wherein the rotor of the rotating electric machine is positioned in a vertical range that includes the vertical position of the rotation axis of the output gear.

8. The control system is configured to receive power from a battery and supply power to the rotating electric machine; The vehicle drive device according to claim 1 , wherein the case is provided with one or more connectors for electrically connecting the battery and the control system.

9. A vehicle drive device as described in Claim 8, wherein the one or more connectors are arranged in a distributed manner on both axial sides of the case.

10. A vehicle drive device as described in Claim 8, wherein at least one of the one or more connectors is positioned at a corner of the third case portion when viewed axially along the axial direction.

11. A vehicle drive device described in any one of claims 1 to 10, wherein the control system includes a power conversion device and a control device that controls the power conversion device.

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