Drive device for vehicles

Abstract

To provide a drive device for vehicles which is equipped with a speed reduction mechanism, with which it is possible to secure a large reduction ratio of the speed reduction mechanism and yet facilitate downsizing.SOLUTION: A drive device (100) for vehicles comprises a rotary electric machine (1), a pair of output members (3), a speed reduction mechanism (4), and a differential gear mechanism (5). The speed reduction mechanism (4) reduces the rotation of the rotary electric machine (1). The differential gear mechanism (5) distributes the rotation transmitted from the speed reduction mechanism (4) to the pair of output members (3). The speed reduction mechanism (4) comprises a first gear (4A) rotated by the rotary electric machine (1), a first counter gear mechanism (41), a second counter gear mechanism (42), and a sixth gear (4F). The first counter gear mechanism (41) is connected to the first gear (4A). The second counter gear mechanism (42) is connected to the first counter gear mechanism (41). The sixth gear (4F) connects the drive between the second counter gear mechanism (42) and the differential gear mechanism (5).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a vehicle drive device including a rotating electrical machine having a rotor and a speed reduction mechanism for reducing the rotation of the rotor.

Background Art

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

[0003] The vehicle drive device (vehicle electric drive unit 1) described in Patent Document 1 includes a rotating electrical machine (motor 3), a speed reduction mechanism (T), a differential transmission mechanism (differential device D), and a pair of output members (left and right output shafts 10L, 10R). The rotation of the rotor (rotor shaft 4) of the rotating electrical machine (motor 3) is reduced by the speed reduction mechanism (T) and transmitted to the pair of output members (left and right output shafts 10L, 10R) via the differential gear mechanism (differential device D).

[0004] The speed reduction mechanism (4) of the vehicle drive device (vehicle electric drive unit 1) described in Patent Document 1 is constituted by a pair of counter gear mechanisms arranged parallel to the rotor (rotor shaft 4). Each of the pair of counter gear mechanisms includes a second gear (reduction gear 15) that meshes with a first gear (pinion gear 8) that rotates integrally with the rotor (rotor shaft 4), and a third gear (reduction gear 16) that rotates integrally with the second gear (reduction gear 15) and transmits rotation to the differential gear mechanism (differential device D). The third gear meshes with a fourth gear (ring gear 20) provided in the differential gear mechanism (differential device D) to transmit rotation to the differential gear mechanism (differential device D).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] By the way, in order to increase the reduction ratio of the speed reduction mechanism (T) described in Patent Document 1, it is necessary to secure a large radial dimension for the second gear (reduction gear 15) and the fourth gear (ring gear 20). That is, when a large reduction ratio of the speed reduction mechanism (T) is secured, the vehicle drive device (vehicle electric drive unit 1) is likely to be enlarged in the radial direction.

[0007] Therefore, in a configuration including a speed reduction mechanism, it is desired to realize a vehicle drive device that is easy to miniaturize while securing a large reduction ratio of the speed reduction mechanism.

Means for Solving the Problems

[0008] The characteristic configuration of the vehicle drive device in view of the above is a rotary electric machine including a rotor, a pair of output members each drivingly connected to a wheel, a speed reduction mechanism for reducing the rotation of the rotor, and a differential input member, and a differential gear mechanism for distributing the rotation transmitted from the speed reduction mechanism to the differential input member to the pair of output members. The vehicle drive device is provided with a differential gear mechanism, wherein the rotor, the pair of output members, and the differential gear mechanism are arranged on a first axis, the speed reduction mechanism is arranged on the first axis, and is connected to rotate integrally with the rotor. The speed reduction mechanism includes a first gear, a second gear meshing with the first gear, and a third gear connected to rotate integrally with the second gear. The speed reduction mechanism further includes a first counter gear mechanism arranged on a second axis which is a different axis from the first axis, a fourth gear meshing with the third gear, and a fifth gear connected to rotate integrally with the fourth gear. The speed reduction mechanism further includes a second counter gear mechanism arranged on a third axis which is a different axis from the first axis and the second axis, and a sixth gear arranged on the first axis, meshing with the fifth gear, and connected to rotate integrally with the differential input member.

[0009] According to this characteristic configuration, before transmitting the rotation of the rotor to the differential gear mechanism, the rotation can be decelerated at three locations: the meshing portion between the first gear and the second gear, the meshing portion between the third gear and the fourth gear, and the meshing portion between the fifth gear and the sixth gear. Therefore, compared with a configuration having only one counter gear mechanism from the rotor to the differential gear mechanism, it is easier to reduce the diameters of a plurality of gears while ensuring a sufficient reduction ratio. Therefore, it is easier to reduce the overall size of the vehicle drive device. Further, according to this configuration, since the reduction mechanism can be configured by a relatively simple combination of gears, it is easier to increase the transmission efficiency and reduce the manufacturing cost compared with a configuration using a planetary gear mechanism as the reduction mechanism.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Mode for Carrying Out the Invention

[0011] The vehicle drive device 100 according to the embodiment will be described with reference to FIGS. 1 to 4. As shown in FIGS. 1 and 2, the vehicle drive device 100 includes a rotary electric machine 1 having a rotor 12, a pair of output members 3 each drivingly connected to a vehicle wheel WH, a reduction mechanism 4, a differential gear mechanism 5, and a case 9. The reduction mechanism 4 and the differential gear mechanism 5 drivingly connect the rotor 12 and the output member 3. The case 9 illustrated in FIG. 1 houses the rotary electric machine 1, the reduction mechanism 4, and the differential gear mechanism 5. And, in the present embodiment, the vehicle drive device 100 includes an inverter unit 6 for controlling the rotary electric machine 1. The inverter unit 6 illustrated in FIG. 1 is housed in the case 9.

[0012] Here, in the present application, "driving connection" refers to a state in which two rotating elements are connected so as to be able to transmit a driving force, including a state in which the two rotating elements are connected so as to rotate integrally, or a state in which the two rotating elements are connected so as to be able to transmit a driving force via one or more transmission members. Such transmission members include various members that transmit rotation at the same speed or with speed change, for example, shafts, gear mechanisms, belts, chains, and the like. Note that the transmission members may include engaging devices that selectively transmit rotation and driving force, such as friction engaging devices and meshing engaging devices.

[0013] Further, "connected so as to rotate integrally" means that a state in which two rotating elements are connected so as to rotate integrally (hereinafter referred to as "integral rotation state") can be realized. That is, "connected so as to rotate integrally" includes both a mode in which the integral rotation state is always realized (a mode in which they are connected so as to rotate integrally) and a mode in which the integral rotation state is selectively realized (a mode in which they can be connected so as to rotate integrally).

[0014] The rotating electrical machine 1 functions as a driving power source for the wheel WH. The rotating electrical machine 1 has a function as a motor (electric motor) that generates power upon receiving power supply and a function as a generator (electric generator) that generates power upon receiving power supply. Specifically, the rotating electrical machine 1 is electrically connected to a power storage device (not shown) such as a battery or a capacitor. Then, the rotating electrical machine 1 performs power running by the power stored in the power storage device to generate a driving force. Further, the rotating electrical machine 1 generates electricity by the driving force transmitted from the wheel WH side to charge the power storage device.

[0015] The rotating electrical machine 1 further includes a stator 11. The stator 11 includes a cylindrical stator core 111. The stator core 111 is fixed to a non-rotating member. In the present embodiment, the stator core 111 is fixed to the case 9 as a non-rotating member. The rotor 12 of the rotating electrical machine 1 includes a cylindrical rotor core 121. The rotor core 121 is rotatably supported with respect to the stator core 111.

[0016] The speed reduction mechanism 4 reduces the rotation speed of the rotor 12. The speed reduction mechanism 4 includes a first gear 4A that is connected to rotate integrally with the rotor 12, a first counter gear mechanism 41, a second counter gear mechanism 42, and a differential input gear 4F. In the present embodiment, the first gear 4A is connected to rotate integrally with the rotor 12, and a state in which the rotor 12 and the first gear 4A are connected to rotate integrally is always realized. The first gear 4A is disposed on the first axis X1. The first counter gear mechanism 41 is connected to the first gear 4A. Further, the first counter gear mechanism 41 is disposed on a second axis X2 that is a different axis from the first axis X1. The second counter gear mechanism 42 is connected to the first counter gear mechanism 41. Further, the second counter gear mechanism 42 is disposed on a third axis X3 that is a different axis from the first axis X1 and the second axis X2. In this example, the first axis X1, the second axis X2, and the third axis X3 are parallel to each other. The differential input gear 4F is connected to the second counter gear mechanism 42. Further, the differential input gear 4F is disposed on the first axis X1. Also, the differential input gear 4F is drivingly connected to the differential gear mechanism 5. Note that the differential input gear 4F corresponds to the "sixth gear".

[0017] In the following description, the direction along the first axis X1 is defined as the "axial direction L" of the vehicle drive device 100. Also, as shown in FIG. 3, the direction orthogonal to the first axis X1 in the vertical view is defined as the "width direction W" of the vehicle drive device 100. Here, the vertical direction is the direction along the vertical direction (the vertical direction in FIGS. 3 and 4) when the vehicle drive device 100 is mounted on the vehicle. In this example, both the second axis X2 and the third axis X3 are arranged on one side in the width direction W with respect to the first axis X1. In this example, the second axis X2 is arranged above the third axis X3, and the first axis X1 is arranged between the second axis X2 and the third axis X3 in the vertical direction. Also, the direction orthogonal to the rotation axis of the rotating member such as the rotor 12 is defined as the "radial direction R" based on each rotation axis. When there is no need to distinguish which rotation axis is the reference or when it is clear which rotation axis is the reference, it may be simply referred to as the "radial direction R". Then, one side in the axial direction L is defined as the first axial side L1. The other side in the axial direction L is defined as the second axial side L2.

[0018] In the present embodiment, the rotor 12, the pair of output members 3, and the differential gear mechanism 5 are arranged on the first axis X1. Also, in the present embodiment, both the first counter gear mechanism 41 and the second counter gear mechanism 42 are arranged so as to overlap the rotary electric machine 1 in the axial direction L view. In addition, the first counter gear mechanism 41 and the second counter gear mechanism 42 are arranged so as to overlap each other in the axial direction L view. Regarding the arrangement of two elements, "overlapping in a specific direction view" means that when a virtual straight line parallel to the line-of-sight direction is moved in each direction orthogonal to the virtual straight line, there is at least a part of the region where the virtual straight line intersects both of the two elements.

[0019] In this embodiment, as shown in FIGS. 1 and 2, the first gear 4A is connected to the rotor 12 by the rotor shaft 2. The rotor shaft 2 includes a shaft member that is connected so as to rotate integrally with the rotor 12. The rotor shaft 2 is fixed to the rotor 12. The first gear 4A is fixed to the rotor shaft 2. In this example, the first gear 4A is a separate member from the rotor shaft 2 and is a member connected to the rotor shaft 2 so as to rotate integrally with the rotor shaft 2. Here, the "separate member" refers to separate members that are separated in the state of the parts before becoming the final product, and includes both those that can be separated in the state of the final product and those that are joined inseparably in the state of the final product. Also, both the case where the plurality of members constituting the "separate member" are of the same material and the case where they are of different materials from each other are included. For example, the connection between the rotor shaft 2 and the first gear 4A includes spline connection, fastening by fastening members such as bolts, and joining by welding. Note that the first gear 4A may be integrally formed with the rotor shaft 2.

[0020] The first counter gear mechanism 41 includes a second gear 4B and a third gear 4C. The second gear 4B meshes with the first gear 4A. The third gear 4C is connected so as to rotate integrally with the second gear 4B. In this embodiment, the third gear 4C is connected so as to rotate integrally with the second gear 4B, and a state in which the second gear 4B and the third gear 4C are connected so as to rotate integrally is always realized. In this embodiment, the third gear 4C is connected to the second gear 4B via the first counter shaft 411. The first counter shaft 411 includes a shaft member that is connected so as to rotate integrally with the second gear 4B and the third gear 4C. At least one of the second gear 4B or the third gear 4C is a separate member from the first counter shaft 411 and is connected to the first counter shaft 411 so as to rotate integrally therewith. And the remainder of the second gear 4B or the third gear 4C is integrally formed with the first counter shaft 411. In this example, the second gear 4B is a separate member from the first counter shaft 411, and the third gear 4C is integrally formed with the first counter shaft 411.

[0021] In the example shown in FIG. 1, the second gear 4B is formed with a larger diameter than the first gear 4A. Also, although not shown, the number of teeth of the second gear 4B is larger than the number of teeth of the first gear 4A. Therefore, when the rotation of the first gear 4A is transmitted to the second gear 4B, the rotational speed of the first countershaft 411 becomes slower than the rotational speed of the first gear 4A. Further, in the example shown in FIG. 1, the third gear 4C is formed with a smaller diameter than the second gear 4B. Therefore, in the axial direction L view, a fourth gear 4D (described later) that meshes with the third gear 4C can also be arranged at a position overlapping the second gear 4B. For this reason, it is easy to form the fourth gear 4D with a large diameter without increasing the dimension in the width direction W of the vehicle drive device 100.

[0022] The second counter gear mechanism 42 includes a fourth gear 4D and a fifth gear 4E. The fourth gear 4D meshes with the third gear 4C. The fifth gear 4E is connected so as to rotate integrally with the fourth gear 4D. In the present embodiment, the fifth gear 4E is connected so as to rotate integrally with the fourth gear 4D, and a state where the fourth gear 4D and the fifth gear 4E are connected so as to rotate integrally is always realized. In the present embodiment, the fourth gear 4D is connected to the fifth gear 4E via the second countershaft 421. The second countershaft 421 includes a shaft member that is connected so as to rotate integrally with the fourth gear 4D and the fifth gear 4E. At least one of the fourth gear 4D or the fifth gear 4E is a separate member from the second countershaft 421 and is connected so as to rotate integrally with the second countershaft 421. And the remainder of the fourth gear 4D or the fifth gear 4E is integrally formed on the second countershaft 421. In this example, the fourth gear 4D is a separate member from the second countershaft 421, and the fifth gear 4E is integrally formed on the second countershaft 421. The fifth gear 4E meshes with the differential input gear 4F. In the example shown in FIG. 1, the differential input gear 4F is formed with a larger diameter than the fifth gear 4E. Also, although not shown, the number of teeth of the differential input gear 4F is larger than the number of teeth of the fifth gear 4E. Therefore, when the rotation of the fifth gear 4E is transmitted to the differential input gear 4F, the rotational speed of the differential input gear 4F becomes slower than the rotational speed of the fifth gear 4E.

[0023] In the example shown in FIG. 1, the fourth gear 4D is formed with a larger diameter than the third gear 4C. Also, although not shown, the number of teeth of the fourth gear 4D is larger than the number of teeth of the third gear 4C. Therefore, when the rotation of the third gear 4C is transmitted to the fourth gear 4D, the rotational speed of the second countershaft 421 becomes slower than the rotational speed of the first countershaft 411. Further, in the example shown in FIG. 1, the fifth gear 4E is formed with a smaller diameter than the fourth gear 4D. Thus, in the axial direction L view, the differential input gear 4F that meshes with the fifth gear 4E can also be arranged at a position overlapping the fourth gear 4D. For this reason, it is easy to form the differential input gear 4F with a large diameter without increasing the dimension in the width direction W of the vehicle drive device 100.

[0024] In the present embodiment, the third gear 4C and the fourth gear 4D are arranged on the second side L2 in the axial direction with respect to the first gear 4A and the second gear 4B. Also, the fifth gear 4E and the differential input gear 4F are arranged on the second side L2 in the axial direction with respect to the third gear 4C and the fourth gear 4D. Therefore, the differential input gear 4F is arranged at a position farther from the rotating electrical machine 1 than the first gear 4A, the second gear 4B, the third gear 4C, and the fourth gear 4D. Therefore, in the axial direction L view, the differential input gear 4F can overlap with the second gear 4B, the third gear 4C, and the fourth gear 4D. For this reason, the differential input gear 4F can be formed with a large diameter without increasing the dimension (for example, the dimension in the width direction W) of the entire vehicle drive device 100 in the axial direction L view. In other words, without increasing the dimension (for example, the dimension in the width direction W) of the entire vehicle drive device 100 in the axial direction L view, it is easy to configure the reduction ratio of the speed reduction mechanism 4 to be large.

[0025] In addition, in the present embodiment, among the gears included in the first counter gear mechanism 41, the gear with the larger outer diameter (large-diameter gear), and among the gears included in the second counter gear mechanism 42, the gear with the larger outer diameter (large-diameter gear) overlap with the rotating electric machine 1 in the axial direction L view. In the example shown in FIG. 1, the second gear 4B and the fourth gear 4D overlap with the rotating electric machine 1 in the axial direction L view. Therefore, it is easy to form the dimension in the width direction W of the entire vehicle drive device 100 to be small. Further, in the present embodiment, the large-diameter gear of the first counter gear mechanism 41 overlaps with the large-diameter gear of the second counter gear mechanism 42 in the axial direction L view. In the example shown in FIG. 1, the second gear 4B and the fourth gear 4D overlap in the axial direction L view. Therefore, it is easy to form the dimension in the width direction W of the entire vehicle drive device 100 to be small.

[0026] In the present embodiment, as shown in FIG. 3, the entire first counter gear mechanism 41 and the entire second counter gear mechanism 42 are arranged on one side in the width direction W with respect to the first axis X1. In the example shown in FIG. 3, the entire first counter gear mechanism 41 and the entire second counter gear mechanism 42 are arranged on the left side toward the paper surface with respect to the first axis X1. Therefore, compared with the case where the entire first counter gear mechanism 41 is arranged at a position opposite to the entire second counter gear mechanism 42 with the first axis X1 interposed therebetween, the distance from the second axis X2 to the third axis X3 in the width direction W becomes smaller. Therefore, it is easy to form the dimension in the width direction W of the entire vehicle drive device 100 to be small.

[0027] As shown in FIG. 1, the differential gear mechanism 5 includes a differential input member 51. The differential gear mechanism 5 distributes the rotation transmitted from the speed reduction mechanism 4 to the differential input member 51 to the pair of output members 3. In the present embodiment, the differential input gear 4F is connected so as to rotate integrally with the differential input member 51.

[0028] In the present embodiment, the rotor 12, the first gear 4A, and the differential gear mechanism 5 are arranged in the described order from the first axial side L1 to the second axial side L2 on the first axis X1. Further, the axial L arrangement region of the differential gear mechanism 5 overlaps with the axial L arrangement regions of the third gear 4C and the fourth gear 4D. Therefore, compared with the case where the axial L arrangement region of the differential gear mechanism 5 does not overlap with the axial L arrangement regions of the third gear 4C and the fourth gear 4D, the axial L dimension of the entire vehicle drive device 100 becomes smaller.

[0029] In the present embodiment, the differential gear mechanism 5 further includes a pair of pinion gears 52 and a pair of side gears 53. Here, both the pair of pinion gears 52 and the pair of side gears 53 are bevel gears.

[0030] The differential input member 51 of the present embodiment is a hollow member that houses a pair of pinion gears 52 and a pair of side gears 53. The differential input member 51 is connected so as to rotate integrally with the differential input gear 4F.

[0031] The pair of pinion gears 52 are arranged to face each other with a space in the radial direction R with respect to the first axis X1. And the pair of pinion gears 52 are attached to a pinion shaft 52a supported so as to rotate integrally with the differential input member 51. Each of the pair of pinion gears 52 is configured to be rotatable (self-rotate) about the pinion shaft 52a and rotatable (revolve) about the first axis X1.

[0032] The pair of side gears 53 mesh with the pair of pinion gears 52. The pair of side gears 53 are arranged to rotate about the first axis X1 as the rotation axis. The pair of side gears 53 are arranged with a space in the axial direction L from each other and facing each other with the pinion shaft 52a interposed therebetween.

[0033] The inverter unit 6 of the present embodiment includes a modularized configuration including an inverter circuit (not shown) connected to a battery (not shown) that stores power, a rotation motor control unit (not shown), a driver (not shown), and a heat sink for cooling the inverter circuit.

[0034] The inverter circuit includes a plurality of switching elements. The inverter circuit includes a plurality of sets of arms for one phase of alternating current configured by a series circuit of an upper-stage switching element on the positive electrode side of direct current and a lower-stage switching element on the negative electrode side. A freewheel diode is provided in parallel with each switching element with the direction from the negative electrode to the positive electrode as the forward direction. As the switching element, for example, a power semiconductor element such as an IGBT (Insulated Gate Bipolar Transistor), a power MOSFET (Metal Oxide Semiconductor Field Effect Transistor), a SiC-MOSFET (Silicon Carbide - Metal Oxide Semiconductor FET), a SiC-SIT (SiC - Static Induction Transistor), and a GaN-MOSFET (Gallium Nitride - MOSFET) can be used.

[0035] For example, a smoothing capacitor (not shown) is provided between the inverter circuit and the battery. The smoothing capacitor smoothes the voltage on the direct current side of the inverter circuit. The smoothing capacitor may or may not be included in the inverter unit 6. Also, a booster converter may be provided, and in this case, the booster converter may be included in the inverter unit 6. The inverter unit 6 includes, for example, a plurality of connection terminals (not shown) respectively corresponding to the stator coils (not shown) of each phase of the stator 11 in the rotation motor 1. The inverter unit 6 is connected to the stator coils of each phase via these plurality of connection terminals.

[0036] The rotation electric machine control unit performs switching control on a plurality of switching elements that constitute an inverter circuit, and converts DC power supplied from a battery into AC power of a plurality of phases. The rotation electric machine control unit performs current feedback control based on the rotation position of the rotor 12 (the magnetic pole position of the permanent magnet 122), the rotation speed of the rotor 12, and the current flowing through the stator coils of each of the three phases. The rotation position of the rotor 12 is detected by a rotation sensor (not shown) such as a resolver or an inductive position sensor. The current flowing through the stator coil is detected by a current sensor (not shown). The driver amplifies the voltage of the switching control signal output from the rotation electric machine control unit, increases the driving force, and supplies it to the inverter circuit.

[0037] In the present embodiment, at least a part of the inverter unit 6 (for example, the smoothing capacitor described above) is between the axial direction L of the rotation electric machine 1 and the differential input gear 4F, and in a view along the axial direction L, it is arranged so as to overlap both the rotation electric machine 1 and the differential input gear 4F. In the example shown in FIG. 1, the inverter unit 6 is between the stator 11 of the rotation electric machine 1 and the differential input gear 4F, and in a view along the axial direction L, it is arranged so as to overlap both the stator 11 and the differential input gear 4F. Further, in detail, in the example shown in FIG. 1, the inverter unit 6 is between the coil end portion 112 of the stator 11 and the differential input gear 4F, and in a view along the axial direction L, it is arranged so as to overlap both the coil end portion 112 and the differential input gear 4F.

[0038] As described above, the case 9 houses the rotation electric machine 1, the speed reduction mechanism 4, and the differential gear mechanism 5. In the present embodiment, the case 9 also houses a pair of output members 3.

[0039] As shown in FIG. 1, in the present embodiment, the case 9 includes an inner portion with a first housing portion A1, a second housing portion A2, and a third housing portion A3. The first housing portion A1 includes a space for housing the rotating electric machine 1. The second housing portion A2 includes a space for housing the speed reduction mechanism 4 and the differential gear mechanism 5. The third housing portion A3 includes a space for housing the inverter unit 6.

[0040] In the present embodiment, the case 9 includes a partition wall portion 91, a first peripheral wall portion 92a, a first side wall 92b, a second peripheral wall portion 93a, a second side wall portion 93b, an intermediate wall portion 94, a third side wall portion 95a, and a wall portion 95b.

[0041] The partition wall portion 91 is formed so as to partition the first housing portion A1 and the second housing portion A2. In the present embodiment, the partition wall portion 91 is formed to extend in the radial direction R. That is, the partition wall portion 91 partitions the first housing portion A1 and the second housing portion A2 in the axial direction L.

[0042] The first peripheral wall portion 92a is formed so as to cover the outside in the radial direction R of the rotating electric machine 1. In the example shown in FIG. 1, the stator 11 of the rotating electric machine 1 is fixed to the first peripheral wall portion 92a. In the present embodiment, the rotating electric machine 1 is of an inner rotor type. That is, the stator 11 is disposed outside in the radial direction R with respect to the rotor 12. Therefore, the stator core 111 is disposed outside in the radial direction R with respect to the rotor core 121.

[0043] Further, in the present embodiment, the rotating electric machine 1 is of a rotating field type. Therefore, a stator coil is wound around the stator core 111. The stator coil is wound around the stator core 111 such that a pair of coil end portions 112 protruding axially on the first side L1 and the second side L2 with respect to the stator core 111 are formed. Further, a permanent magnet 122 is provided on the rotor core 121.

[0044] The first side wall 92b is formed so as to cover the first side L1 in the axial direction of the rotating electrical machine 1. In the present embodiment, the first peripheral wall portion 92a is formed in a cylindrical shape with the first side L1 in the axial direction being open. And the opening of the first side L1 in the axial direction of the first peripheral wall portion 92a is blocked by the first side wall 92b. On the other hand, a partition portion 91 is integrally provided at a portion of the first peripheral wall portion 92a on the second side L2 in the axial direction with respect to the rotating electrical machine 1.

[0045] The second peripheral wall portion 93a is formed so as to cover the outside in the radial direction R of the speed reduction mechanism 4 and the differential gear mechanism 5. The second side wall portion 93b is formed so as to cover the second side L2 in the axial direction of the speed reduction mechanism 4 and the differential gear mechanism 5. In the present embodiment, the second peripheral wall portion 93a is formed in a cylindrical shape with the second side L2 in the axial direction being open. And the opening of the second side L2 in the axial direction of the second peripheral wall portion 93a is blocked by the second side wall portion 93b. On the other hand, a partition portion 91 is integrally provided at a portion of the second peripheral wall portion 93a on the first side L1 in the axial direction with respect to the first gear 4A.

[0046] In the present embodiment, the first accommodation portion A1 is formed by the partition portion 91, the first peripheral wall portion 92a, and the first side wall 92b. That is, a space surrounded by the partition portion 91, the first peripheral wall portion 92a, and the first side wall 92b inside the case 9 is formed as the first accommodation portion A1.

[0047] Also, in the present embodiment, the second accommodation portion A2 is formed by the partition portion 91, the second peripheral wall portion 93a, and the second side wall portion 93b. That is, a space surrounded by the partition portion 91, the second peripheral wall portion 93a, and the second side wall portion 93b inside the case 9 is formed as the second accommodation portion A2.

[0048] In this embodiment, the intermediate wall portion 94 is a portion that supports at least any one of the rotor 12, the speed reduction mechanism 4, and the differential gear mechanism 5 inside the case 9. The intermediate wall portion 94 extends from the outside to the inside in the radial direction R inside the second housing portion A2. In the example shown in FIG. 1, the intermediate wall portion 94 is fixed to the second peripheral wall portion 93a. The intermediate wall portion 94 overlaps with the arrangement region in the axial direction L of at least any one of the rotor 12, the first counter gear mechanism 41, the second counter gear mechanism 42, and the differential gear mechanism 5. Note that if the case 9 can support the rotor 12, the speed reduction mechanism 4, and the differential gear mechanism 5, the intermediate wall portion 94 may not be provided.

[0049] The third side wall portion 95a is formed so as to cover the outside in the axial direction L and the width direction W of the inverter unit 6. In the example shown in FIG. 1, the third side wall portion 95a is formed so as to extend from the outer peripheral surfaces of the first peripheral wall portion 92a and the second peripheral wall portion 93a toward the outside in the radial direction R. And the wall portion 95b covers the inverter unit 6 from the outside in the radial direction R (here, the upper side). In this embodiment, the third housing portion A3 is formed by the first peripheral wall portion 92a, the second peripheral wall portion 93a, the third side wall portion 95a, and the wall portion 95b. That is, a space surrounded by the first peripheral wall portion 92a, the second peripheral wall portion 93a, the third side wall portion 95a, and the wall portion 95b inside the case 9 is formed as the third housing portion A3. In the example shown in FIG. 1, the inverter unit 6 is housed in the third housing portion A3 so as to face both the first peripheral wall portion 92a and the second peripheral wall portion 93a.

[0050] In this embodiment, the rotor shaft 2 to which the rotor 12 is fixed is housed in the first housing portion A1 and the second housing portion A2, and is rotatably supported by the case 9. Further, the speed reduction mechanism 4 and the differential gear mechanism 5 are housed in the second housing portion A2, and are rotatably supported by the case 9. Hereinafter, the support structure of the rotor shaft 2, the speed reduction mechanism 4, and the differential gear mechanism 5 will be described.

[0051] In this embodiment, the rotor shaft 2 includes a first shaft end portion 21, a rotor fixing portion 22, a bearing fitting portion 23, a first gear connecting portion 24, and a second shaft end portion 25. The first shaft end portion 21, the rotor fixing portion 22, the bearing fitting portion 23, the first gear connecting portion 24, and the second shaft end portion 25 are arranged in the described order along the axial direction L from the first axial side L1 to the second axial side L2.

[0052] The first shaft end portion 21 is a portion supported by a first bearing B1 described later. In the example shown in FIG. 1, the first shaft end portion 21 is formed in a cylindrical shape having an axis along the axial direction L. The rotor 12 is fixed to the rotor fixing portion 22. In this embodiment, the rotor fixing portion 22 is formed in a cylindrical shape having an axis along the axial direction L. In the example shown in FIG. 1, the rotor fixing portion 22 is arranged so as to protrude from the rotor 12 toward each of the first axial side L1 and the second axial side L2 in the axial direction. Further, the outer diameter of the rotor fixing portion 22 is formed to be smaller than that of the first shaft end portion 21. The bearing fitting portion 23 is for fitting a third bearing B3 described later. The first gear connecting portion 24 is a portion to which the first gear 4A is connected. In this example, the first gear 4A is spline-engaged with the first gear connecting portion 24. The second shaft end portion 25 is a portion supported by a second bearing B2 described later. In the example shown in FIG. 1, the second shaft end portion 25 is formed in a cylindrical shape having an axis along the axial direction L.

[0053] As shown in FIG. 1, the rotor 12 and the rotor shaft 2 are connected to each other in a state where the inner peripheral surface of the rotor 12 and the outer peripheral surface of the rotor shaft 2 are in contact. In this embodiment, the inner peripheral surface of the rotor 12 is the inner peripheral surface of the rotor core 121. In this embodiment, the outer peripheral surface of the rotor shaft 2 is the outer peripheral surface of the rotor fixing portion 22. Also, the rotor 12 and the first gear 4A are arranged at different positions in the axial direction L. And the first gear 4A is arranged on the second axial side L2 with respect to the rotor 12.

[0054] As shown in FIGS. 1 and 2, the rotor shaft 2 is rotatably supported with respect to the case 9 at three positions in the axial direction L by the first bearing B1, the second bearing B2, and the third bearing B3.

[0055] The first bearing B1 is disposed on the first axial side L1 with respect to the rotor 12. The first bearing B1 rotatably supports the rotor shaft 2. In the present embodiment, the first bearing B1 is disposed so as to support the inner peripheral surface of the first axial end portion 21 of the rotor shaft 2 from the inner side in the radial direction R. In the example shown in FIG. 1, the first side wall 92b of the case 9 includes a first bearing support portion 92c. The first bearing support portion 92c is formed in a cylindrical shape protruding in the second axial side L2 so as to overlap the first axial end portion 21 in a view in the radial direction R along the radial direction R inside the first axial end portion 21. And the first bearing B1 is disposed between the outer peripheral surface of the first bearing support portion 92c and the inner peripheral surface of the first axial end portion 21.

[0056] The second bearing B2 is disposed on the second axial side L2 with respect to the first gear 4A. The second bearing B2 rotatably supports the second axial end portion 25 provided on the rotor shaft 2. In the present embodiment, the second bearing B2 is disposed so as to support the outer peripheral surface of the second axial end portion 25 from the outer side in the radial direction R. In the example shown in FIG. 1, the case 9 includes a second bearing support portion 94a. The second bearing support portion 94a is formed in the intermediate wall portion 94. The second bearing support portion 94a is formed in a cylindrical shape protruding in the first axial side L1 so as to overlap the second axial end portion 25 in a view in the radial direction R along the radial direction R outside the second axial end portion 25. And the second bearing B2 is disposed between the inner peripheral surface of the second bearing support portion 94a and the outer peripheral surface of the second axial end portion 25.

[0057] The third bearing B3 is disposed between the rotor 12 and the first gear 4A in the axial direction L. The third bearing B3 rotatably supports the rotor shaft 2. In the present embodiment, the third bearing B3 is arranged to support the bearing fitting portion 23 from the outer side in the radial direction R. In this example, the third bearing B3 is arranged to support the outer peripheral surface of the bearing fitting portion 23 from the outer side in the radial direction R. In the example shown in FIG. 1, the case 9 includes a third bearing support portion 91a that supports the third bearing B3 from the outer side in the radial direction R. And the third bearing B3 is supported by the third bearing support portion 91a. The third bearing support portion 91a is formed in a cylindrical shape extending along the axial direction L so as to overlap the bearing fitting portion 23 in a view in the radial direction R along the radial direction R outside the bearing fitting portion 23 of the rotor shaft 2 in the radial direction R.

[0058] The first countershaft 411 is formed to extend along the second axis X2. In the present embodiment, the first countershaft 411 is rotatably supported by the case 9 by the first counter bearing B11 and the second counter bearing B12.

[0059] In the present embodiment, the first counter bearing B11 is disposed on the first side L1 in the axial direction with respect to the second gear 4B. In the example shown in FIG. 1, the first counter bearing B11 is disposed inside the radial direction R with respect to the second gear 4B with the second axis X2 as a reference.

[0060] Also, in the present embodiment, the first counter bearing B11 is arranged to support the outer peripheral surface of the first countershaft 411 from the outer side in the radial direction R. In the example shown in FIG. 1, the partition wall portion 91 of the case 9 has a first counter bearing support portion 91b. The first counter bearing support portion 91b is formed in a cylindrical shape protruding toward the second side L2 in the axial direction inside the radial direction R from the second gear 4B. And the first counter bearing B11 is disposed between the inner peripheral surface of the first counter bearing support portion 91b and the outer peripheral surface of the first countershaft 411.

[0061] In this embodiment, the second counter bearing B12 is arranged on the second axial side L2 with respect to the third gear 4C in the axial direction. Further, in this embodiment, the second counter bearing B12 is arranged to support the outer peripheral surface of the first counter shaft 411 from the outer side in the radial direction R. In the example shown in FIG. 1, the case 9 includes a second counter bearing support portion 94c. The second counter bearing support portion 94c is formed in the intermediate wall portion 94. The second counter bearing support portion 94c is formed in a cylindrical shape having an axis along the axial direction L, and is arranged on the second axial side L2 with respect to the third gear 4C so as to be separated from the third gear 4C. Thereby, the second counter bearing support portion 94c is formed in a cylindrical shape that overlaps the first counter shaft 411 in a radial view along the radial direction R outside the first counter shaft 411 in the radial direction R. And the second counter bearing B12 is arranged between the inner peripheral surface of the second counter bearing support portion 94c and the outer peripheral surface of the first counter shaft 411. Thus, in this embodiment, the second counter bearing B12 is arranged on the second axial side L2 with respect to the second bearing B2.

[0062] The second counter shaft 421 is formed to extend along the third axis X3. In this embodiment, the second counter shaft 421 is rotatably supported by the case 9 by the third counter bearing B13 and the fourth counter bearing B14.

[0063] In this embodiment, the third counter bearing B13 is arranged on the first axial side L1 with respect to the fourth gear 4D. In the example shown in FIG. 1, the third counter bearing B13 is arranged inside the radial direction R with respect to the fourth gear 4D based on the third axis X3.

[0064] In addition, in the present embodiment, the third counter bearing B13 is arranged to support the outer peripheral surface of the second counter shaft 421 from the outer side in the radial direction R. In the example shown in FIG. 1, the case 9 includes a third counter bearing support portion 94d. The third counter bearing support portion 94d is formed in the intermediate wall portion 94. Further, the third counter bearing support portion 94d is formed in a cylindrical shape protruding toward the second axial side L2 on the inner side in the radial direction R than the fourth gear 4D. And the third counter bearing B13 is arranged between the inner peripheral surface of the third counter bearing support portion 94d and the outer peripheral surface of the second counter shaft 421.

[0065] In the present embodiment, the fourth counter bearing B14 is arranged on the second axial side L2 with respect to the fifth gear 4E. Also, in the present embodiment, the fourth counter bearing B14 is arranged to support the outer peripheral surface of the second counter shaft 421 from the outer side in the radial direction R. In the example shown in FIG. 1, the case 9 has a fourth counter bearing support portion 93d. The fourth counter bearing support portion 93d is formed in the second side wall portion 93b. The fourth counter bearing support portion 93d is formed in a cylindrical shape having an axis along the axial direction L, and is arranged on the second axial side L2 with respect to the fifth gear 4E so as to be separated from the fifth gear 4E. Thereby, the fourth counter bearing support portion 93d is formed in a cylindrical shape overlapping the second counter shaft 421 in a view in the radial direction R along the radial direction R on the outer side in the radial direction R than the second counter shaft 421. And the fourth counter bearing B14 is arranged between the inner peripheral surface of the fourth counter bearing support portion 93d and the outer peripheral surface of the second counter shaft 421.

[0066] In the present embodiment, the differential gear mechanism 5 is rotatably supported with respect to the case 9 by the first differential bearing B21 and the second differential bearing B22. In the example shown in FIG. 1, the differential input member 51 is rotatably supported with respect to the case 9 by the first differential bearing B21 and the second differential bearing B22.

[0067] In this embodiment, the first differential bearing B21 is arranged to support the end portion of the differential input member 51 on the first axial side L1 from the outside in the radial direction R. In the example shown in FIG. 1, the case 9 includes a first differential bearing support portion 94b. The first differential bearing support portion 94b is formed in the intermediate wall portion 94. The first differential bearing support portion 94b is formed in a cylindrical shape having an axis along the axial direction L, and is arranged so as to overlap the end portion of the differential input member 51 on the first axial side L1 in the radial direction R view along the radial direction R outside the end portion of the differential input member 51 on the first axial side L1 in the axial direction. Then, the first differential bearing B21 is arranged between the inner peripheral surface of the first differential bearing support portion 94b and the outer peripheral surface of the end portion of the differential input member 51 on the first axial side L1.

[0068] Also, in this embodiment, the second differential bearing B22 is arranged to support the end portion of the differential input member 51 on the second axial side L2 from the outside in the radial direction R. In the example shown in FIG. 1, the second side wall portion 93b of the case 9 includes a second differential bearing support portion 93c. The second differential bearing support portion 93c is formed in a cylindrical shape having an axis along the axial direction L, and is arranged so as to overlap the end portion of the differential input member 51 on the second axial side L2 in the radial direction R view along the radial direction R outside the end portion of the differential input member 51 on the second axial side L2 in the axial direction. Then, the second differential bearing B22 is arranged between the inner peripheral surface of the second differential bearing support portion 93c and the outer peripheral surface of the end portion of the differential input member 51 on the second axial side L2.

[0069] In this embodiment, each of the pair of output members 3 is connected so as to rotate integrally with the side gear 53. And each of the pair of output members 3 is connected so as to rotate integrally with a drive shaft DS that is drivingly connected to the wheel WH. In the example shown in FIG. 1, each of the pair of output members 3 is formed in a cylindrical shape having the first axis X1 as the axis. And they are connected to each other by spline engagement with the drive shaft DS arranged inside in the radial direction R with respect to each of the pair of output members 3.

[0070] The vehicle drive device 100 of the present embodiment includes a supply mechanism 7 that supplies cooled oil to various locations within the case 9. Hereinafter, the supply mechanism 7 will be described with reference to FIG. 4.

[0071] The supply mechanism 7 includes an oil pump 71 that circulates the oil within the case 9, and an oil cooler 72 for cooling the oil circulated by the oil pump 71. The oil pump 71 of the present embodiment sucks the oil within the case 9 and discharges it toward various locations within the case 9. The oil pump 71 includes, for example, a gear pump, a vane pump, or the like. In the present embodiment, the suction port (not shown) through which the oil pump 71 sucks the oil is immersed in the oil stored in the storage portion 73. On the other hand, the discharge port of the oil pump 71 is connected to an oil passage 74 formed in the case 9. The oil passage 74 leads to the locations that require the oil. The oil discharged from the oil pump 71 reaches each mechanical element through the oil passage 74. The oil discharged from the oil pump 71 is used, for example, for cooling the rotating electric machine 1 and lubricating each mechanical element within the case 9. Here, each mechanical element includes gears and bearings. Further, the oil cooler 72 of the present embodiment performs heat exchange between the oil discharged from the oil pump 71 and a refrigerant described later. In the example shown in FIG. 4, the oil cooler 72 includes a water-cooled heat exchanger that performs heat exchange between the cooling water for cooling and the oil. In the present embodiment, the oil cooler 72 is housed in the case 9.

[0072] In the present embodiment, at least one of the first counter gear mechanism 41 and the second counter gear mechanism 42 is arranged so as to overlap at least one of the oil pump 71 and the oil cooler 72 in a view along the axial direction L. In the example shown in FIG. 4, the oil pump 71 overlaps with the second counter gear mechanism 42 in a view along the axial direction L. And the oil cooler 72 overlaps with both the first counter gear mechanism 41 and the second counter gear mechanism 42 in a view along the axial direction L.

[0073] Hereinafter, a cooling mechanism 8 for cooling the rotating electrical machine 1 and the inverter unit 6 will be described. The cooling mechanism 8 circulates a refrigerant inside the case 9, the rotating electrical machine 1, or the inverter unit 6. The refrigerant includes a liquid refrigerant such as cooling water and outside air outside the case 9. Such a refrigerant exchanges heat with the rotating electrical machine 1 and the inverter unit 6. Thereby, the rotating electrical machine 1 and the inverter unit 6 are cooled. In the example shown in FIG. 4, the liquid refrigerant exchanges heat with the rotating electrical machine 1 and the inverter unit 6.

[0074] The cooling mechanism 8 of the present embodiment includes a first heat exchange portion 81, a storage portion 73, a second heat exchange portion 82, and a refrigerant flow path 80. The first heat exchange portion 81 exchanges heat between the inverter unit 6 and the refrigerant. The storage portion 73 is provided at the lower part of the case 9. Oil is stored in the storage portion 73. The second heat exchange portion 82 exchanges heat between the oil stored in the storage portion 73 and the refrigerant. The refrigerant flow path 80 is provided in the case 9. The refrigerant flow path 80 is configured such that the refrigerant flows in the order of the first heat exchange portion 81, the oil cooler 72, and the second heat exchange portion 82. In the present embodiment, the oil cooler 72 exchanges heat between the oil and the refrigerant.

[0075] The refrigerant flow path 80 includes a first refrigerant flow path 80A and a second refrigerant flow path 80B. The first refrigerant flow path 80A connects the first heat exchange portion 81 and the oil cooler 72. The second refrigerant flow path 80B connects the oil cooler 72 and the second heat exchange portion 82. In the example shown in FIG. 4, the first refrigerant flow path 80A and the second refrigerant flow path 80B are formed inside the wall of the case 9. Since the first refrigerant flow path 80A and the second refrigerant flow path 80B are formed inside the wall of the case 9, an intermediate hose required in the case of an external structure is not necessary, and it is easy to form the entire vehicle drive device 100 into a small configuration.

[0076] In this embodiment, the refrigerant flow path 80 further includes a supply flow path 80C for supplying refrigerant to the inverter unit 6 and a discharge flow path 80D for discharging the refrigerant supplied to the second heat exchange portion 82. The supply flow path 80C communicates from the outside to the inside of the third housing portion A3. Further, the discharge flow path 80D communicates the inside of the second heat exchange portion 82 with the outside. In the example shown in FIG. 4, the discharge flow path 80D is a pipe for flowing the refrigerant inside the case 9 to the outside of the case 9. In the example shown in FIG. 4, in order to allow the refrigerant to circulate outside the case 9 as well, the supply flow path 80C and the discharge flow path 80D communicate the inside and the outside of the case 9. However, the refrigerant flow path 80 may be configured to flow the refrigerant only inside the case 9. In this case, the refrigerant flow path 80 is formed only inside the case 9.

[0077] In this embodiment, the first heat exchange portion 81 includes a flow path (for example, a water path) formed in the inverter unit 6 housed in the third housing portion A3. The first heat exchange portion 81 is formed inside the inverter unit 6 such that refrigerant (for example, cooling water) flows along a heat sink thermally connected to a plurality of switching elements constituting an inverter circuit (not shown). Thereby, it is possible to satisfactorily cool the switching elements having a relatively large heat generation amount during vehicle travel.

[0078] In this embodiment, the second heat exchange portion 82 is arranged in the case 9 in parallel with the storage portion 73. The refrigerant flowing through the second heat exchange portion 82 cools the oil stored in the storage portion 73 by heat exchange inside the case 9. In the example shown in FIG. 4, the second heat exchange portion 82 is arranged in the first housing portion A1. The second heat exchange portion 82 is arranged in contact with the storage portion 73 with a wall therebetween so that the oil stored in the storage portion 73 and the refrigerant flowing through the second heat exchange portion 82 do not mix at the lower part of the first housing portion A1.

[0079] In this embodiment, the first refrigerant flow path 80A is disposed at a position overlapping at least one of the first counter gear mechanism 41 and the second counter gear mechanism 42 in the axial direction L view. Further, the second refrigerant flow path 80B is disposed at a position overlapping at least the other of the first counter gear mechanism 41 and the second counter gear mechanism 42 in the axial direction L view. In this embodiment, the first refrigerant flow path 80A overlaps the first counter gear mechanism 41 in the axial direction L view. Further, the second refrigerant flow path 80B overlaps the second counter gear mechanism 42 in the axial direction L view.

[0080] 〔Other Embodiments〕 (1) In the above embodiment, the bevel gear type differential gear mechanism 5 has been described by way of example. However, the differential gear mechanism 5 may be a planetary gear type. Further, the differential gear mechanism 5 may be a planetary gear type including a double pinion. In this case, the differential input member 51 becomes a member that rotates integrally with the ring gear.

[0081] (2) In the above embodiment, it has been described that the entire first counter gear mechanism 41 is disposed on one side in the width direction W with respect to the first axis X1. However, a part of the first counter gear mechanism 41 may be disposed on the other side in the width direction W with respect to the first axis X1. Similarly, in the above embodiment, it has been described that the entire second counter gear mechanism 42 is disposed on one side in the width direction W with respect to the first axis X1. However, a part of the second counter gear mechanism 42 may be disposed on the other side in the width direction W with respect to the first axis X1.

[0082] (3) In the above embodiment, it has been described that the first axis X1, the second axis X2, and the third axis X3 are parallel to each other. However, a positional relationship in which some of the axes are three-dimensionally intersecting with respect to other axes may be acceptable. For example, the first axis X1 may have a positional relationship of three-dimensionally intersecting with respect to the second axis X2.

[0083] (4) In the above-described embodiment, it was explained that the inverter unit 6 is arranged so as to overlap both the rotating electric machine 1 and the differential input gear 4F in the axial direction L view along the axial direction L. However, the inverter unit 6 may overlap only the rotating electric machine 1 in the axial direction L view along the axial direction L. Conversely, the inverter unit 6 may overlap only the differential input gear 4F in the axial direction L view along the axial direction L.

[0084] (5) In the above-described embodiment, it was explained that the oil discharged from the oil pump 71 cools the rotating electric machine 1 and each mechanical element in the case 9. However, the oil discharged from the oil pump 71 may be used only for cooling the rotating electric machine 1. In this case, the supply of lubricating oil for lubricating the gear mechanism and bearings includes immersing a part of the gear mechanism and the like in the lubricating oil and scraping up the lubricating oil by the rotation of the gear mechanism and the like. Conversely, the oil discharged from the oil pump 71 may be used only for lubricating various mechanical elements. In this case, the cooling structure of the rotating electric machine 1 is a water-cooled type or an air-cooled type.

[0085] (6) In the above-described embodiment, it was explained that the oil passage 74 is formed in the case 9. However, the oil passage 74 may be formed by a pipe or the like which is a separate member from the case 9. In this case, since there is no need to form the oil passage 74 in the case 9, the structure of the case 9 becomes simple. Further, the oil passage 74 may be formed by combining the case 9 and the pipe.

[0086] (7) The driving method of the oil pump 71 may be either a mechanical type or an electric type. The mechanical oil pump 71 may be operated, for example, by drivingly connecting it to a driving source by a transmission element such as a gear mechanism. Examples of such a driving source include the rotating electric machine 1 and an internal combustion engine. Further, in the case of an electric oil pump 71, for example, a motor for driving the oil pump 71 may be provided separately from the rotating electric machine 1 and operated by drivingly connecting the motor.

[0087] (8) In the above-described embodiment, it has been described that the oil pump 71 overlaps with the second counter gear mechanism 42 in the axial direction L view. However, the oil pump 71 may overlap with the first counter gear mechanism 41 in the axial direction L view. Further, the oil pump 71 may overlap with both the first counter gear mechanism 41 and the second counter gear mechanism 42 in the axial direction L view. Also, it has been described that the oil cooler 72 overlaps with both the first counter gear mechanism 41 and the second counter gear mechanism 42 in the axial direction L view. However, the oil cooler 72 may overlap with either one of the first counter gear mechanism 41 or the second counter gear mechanism 42 in the axial direction L view.

[0088] (9) In the above-described embodiment, it has been described that the oil cooler 72 includes a water-cooled type. In addition, as the oil cooler 72, there is an air-cooled heat exchanger that performs heat exchange between oil and air. Examples of this air include the air outside the case 9. Further, the oil cooler 72 includes a heat exchanger or the like that performs heat exchange between the refrigerant used in the air conditioner and oil.

[0089] (10) In the above-described embodiment, it has been described that the first refrigerant flow path 80A overlaps with the first counter gear mechanism 41 in the axial direction L view, and the second refrigerant flow path 80B overlaps with the second counter gear mechanism 42 in the axial direction L view. However, the first refrigerant flow path 80A may overlap with the second counter gear mechanism 42. Further, the first refrigerant flow path 80A may overlap with both the first counter gear mechanism 41 and the second counter gear mechanism 42 in the axial direction L view. Similarly, the second refrigerant flow path 80B may overlap with the first counter gear mechanism 41. Further, the second refrigerant flow path 80B may overlap with both the first counter gear mechanism 41 and the second counter gear mechanism 42 in the axial direction L view.

[0090] (11) In the above-described embodiment, it has been described that the first refrigerant flow path 80A is formed inside the wall of the case 9. However, the first refrigerant flow path 80A may be formed by a pipe that is a separate member from the case 9. In this case, the pipe may be provided either outside the case 9 or inside the case 9. Similarly, the second refrigerant flow path 80B may also be formed by a pipe as described above.

[0091] (12) Incidentally, the configurations disclosed in the above-described embodiments can be applied in combination with the configurations disclosed in other embodiments as long as there is no contradiction. Regarding other configurations as well, all the embodiments disclosed in this specification are merely examples in all respects. Therefore, various modifications can be made as appropriate within the scope not departing from the gist of the present disclosure.

[0092] [Summary of this Embodiment] The summary of the embodiment related to the vehicle drive device (100) described above will be described below.

[0093] The vehicle drive device (100) includes a rotary electric machine (1) having a rotor (12), a pair of output members (3) each drivingly connected to a wheel (WH), a speed reduction mechanism (4) for reducing the rotation of the rotor (12), and a differential input member (51), and a differential gear mechanism (5) for distributing the rotation transmitted from the speed reduction mechanism (4) to the differential input member (51) to the pair of output members (3). The vehicle drive device (100) is provided with a first counter gear mechanism (41) disposed on a second axis (X2) which is an axis different from the first axis (X1), a fourth gear (4D) meshing with the third gear (4C), and a fifth gear (4E) connected to rotate integrally with the fourth gear (4D). The vehicle drive device (100) is provided with a second counter gear mechanism (42) disposed on a third axis (X3) which is an axis different from the first axis (X1) and the second axis (X2), a sixth gear (4F) disposed on the first axis (X1), meshing with the fifth gear (4E), and connected to rotate integrally with the differential input member (51).

[0094] According to this configuration, before transmitting the rotation of the rotor (12) to the differential gear mechanism (5), the rotation can be decelerated at three locations: the meshing portion between the first gear (4A) and the second gear (4B), the meshing portion between the third gear (4C) and the fourth gear (4D), and the meshing portion between the fifth gear (4E) and the sixth gear (4F). Therefore, compared with a configuration having only one counter gear mechanism from the rotor (12) to the differential gear mechanism (5), it is easier to reduce the diameters of a plurality of gears while ensuring a sufficient reduction ratio. Therefore, it is easier to reduce the overall size of the vehicle drive device (100). Also, according to this configuration, since the reduction mechanism (4) can be configured by a relatively simple combination of gears, it is easier to increase the transmission efficiency and reduce the manufacturing cost compared with a configuration using a planetary gear mechanism as the reduction mechanism (4).

[0095] Here, the first axis (X1), the second axis (X2), and the third axis (X3) are parallel to each other. Taking the direction along the first axis (X1) as the axial direction (L) and the direction perpendicular to the first axis (X1) in a top - down view as the width direction (W), both the second axis (X2) and the third axis (X3) are arranged on one side of the width direction (W) with respect to the first axis (X1). Both the first counter gear mechanism (41) and the second counter gear mechanism (42) are arranged so as to overlap the rotary electric machine (1) in the axial direction (L) view, and it is preferable that the first counter gear mechanism (41) and the second counter gear mechanism (42) overlap each other in the axial direction (L) view.

[0096] According to this configuration, it is easy to keep the size of the vehicle drive device (100) small in the axial direction (L) view.

[0097] Also, with the direction along the first axis (X1) being the axial direction (L), one side of the axial direction (L) being the first axial side (L1), and the other side of the axial direction (L) being the second axial side (L2), the rotor (12), the first gear (4A), and the differential gear mechanism (5) are arranged in the described order from the first axial side (L1) to the second axial side (L2) on the first axis (X1). The third gear (4C) and the fourth gear (4D) are arranged on the second axial side (L2) relative to the first gear (4A) and the second gear (4B). The fifth gear (4E) and the sixth gear (4F) are arranged on the second axial side (L2) relative to the third gear (4C) and the fourth gear (4D). It is preferable that the axial direction (L) arrangement region of the differential gear mechanism (5) overlaps with the axial direction (L) arrangement region of the third gear (4C) and the fourth gear (4D).

[0098] According to this configuration, the rotor (12) is arranged on the first axial side (L1) with respect to the first gear (4A), and the differential gear mechanism (5) is arranged on the second axial side (L2) with respect to the first gear (4A). The third gear (4C) and the fourth gear (4D) are arranged on the second axial side (L2) with respect to the first gear (4A) and the second gear (4B). The fifth gear (4E) and the sixth gear (4F) are arranged on the second axial side (L2) with respect to the third gear (4C) and the fourth gear (4D). The sixth gear (4F) is connected so as to rotate integrally with the differential input member (51). Therefore, the transmission of the driving force from the rotor (12) to the differential input member (51) can be made to proceed from the first axial side (L1) to the second axial side (L2). Therefore, it is easy to simplify the gear arrangement of the speed reduction mechanism (4). Also, according to this configuration, since the axial direction (L) arrangement region of the differential gear mechanism (5) overlaps with the axial direction (L) arrangement region of the third gear (4C) and the fourth gear (4D), it is easy to reduce the axial direction (L) dimension of the vehicle drive device (100) compared to the case where they do not overlap.

[0099] Furthermore, an inverter unit (6) for driving and controlling the rotating electric machine (1) is further provided. Taking the direction along the first axis (X1) as the axial direction (L), at least a part of the inverter unit (6) is located between the rotating electric machine (1) and the sixth gear (4F) in the axial direction (L), and is preferably arranged so as to overlap both the rotating electric machine (1) and the sixth gear (4F) in the axial direction (L) view along the axial direction (L).

[0100] According to this configuration, when the vehicle drive device (100) includes the inverter unit (6), since both the rotating electric machine (1) and the sixth gear (4F) are arranged so as to overlap the inverter unit (6) in the axial direction (L) view, it is easier to suppress the size of the vehicle drive device (100) in the axial direction (L) view as compared with the case where they are arranged so as not to overlap. In addition, at least a part of the inverter unit (6) can be arranged by utilizing the space generated between the rotating electric machine (1) and the sixth gear (4F) in the axial direction (L). Therefore, it is easy to reduce the size of the vehicle drive device (100).

[0101] Furthermore, a case (9) for housing the rotating electric machine (1), the speed reduction mechanism (4), and the differential gear mechanism (5), an oil pump (71) for sucking and circulating the oil in the case (9), and an oil cooler (72) for cooling the oil circulated by the oil pump (71) are further provided. Taking the direction along the first axis (X1) as the axial direction (L), at least one of the first counter gear mechanism (41) and the second counter gear mechanism (42) is preferably arranged so as to overlap at least one of the oil pump (71) and the oil cooler (72) in the axial direction (L) view along the axial direction (L).

[0102] According to this configuration, since at least one of the first counter gear mechanism (41) and the second counter gear mechanism (42) is arranged so as to overlap at least one of the oil pump (71) and the oil cooler (72) when viewed in the axial direction (L), it is easier to suppress the size of the vehicle drive device (100) when viewed in the axial direction (L) compared to the case where they are arranged so as not to overlap.

[0103] Further, an inverter unit (6) for driving and controlling the rotating electric machine (1), a first heat exchange part (81) that performs heat exchange between the inverter unit (6) and the refrigerant, a storage part (73) provided at the lower part of the case (9) where the oil is stored, and a second heat exchange part (82) that performs heat exchange between the oil stored in the storage part (73) and the refrigerant are further provided. The oil cooler (72) performs heat exchange between the oil and the refrigerant. The case (9) is provided with a refrigerant flow path (80) configured such that the refrigerant flows in the order of the first heat exchange part (81), the oil cooler (72), and the second heat exchange part (82). The refrigerant flow path (80) includes a first refrigerant flow path (80A) connecting the first heat exchange part (81) and the oil cooler (72), and a second refrigerant flow path (80B) connecting the oil cooler (72) and the second heat exchange part (82). When viewed in the axial direction (L), the first refrigerant flow path (80A) is arranged at a position overlapping at least one of the first counter gear mechanism (41) and the second counter gear mechanism (42), and when viewed in the axial direction (L), the second refrigerant flow path (80B) is preferably arranged at a position overlapping at least the other of the first counter gear mechanism (41) and the second counter gear mechanism (42).

[0104] According to this configuration, at least a part of the refrigerant flow path (80) can be arranged by utilizing the space overlapping the first counter gear mechanism (41) and the second counter gear mechanism (42) when viewed in the axial direction (L). Therefore, it is easy to reduce the size of the entire vehicle drive device (100).

Industrial Applicability

[0105] The technology according to the present disclosure can be used in a vehicle drive device including a rotating electric machine having a rotor and a speed reduction mechanism for reducing the rotation of the rotor.

Explanation of Signs

[0106] 100: Vehicle drive device, 1: Rotating electric machine, 12: Rotor, 3: Output member, 4: Speed reduction mechanism, 4A: First gear, 41: First counter gear mechanism, 4B: Second gear, 4C: Third gear, 42: Second counter gear mechanism, 4D: Fourth gear, 4E: Fifth gear, 4F: Differential input gear (sixth gear), 5: Differential gear mechanism, 51: Differential input member, 6: Inverter unit, 71: Oil pump, 72: Oil cooler, 73: Storage section, 81: First heat exchange section, 82: Second heat exchange section, 80: Refrigerant flow path, 80A: First refrigerant flow path, 80B: Second refrigerant flow path, 9: Case, L: Axial direction, L1: First axial side, L2: Second axial side, R: Radial direction, WH: Wheel, X1: First axis center, X2: Second axis center, X3: Third axis center

Claims

1. A rotating electrical machine having a rotor, A pair of output members each drivingly connected to a wheel, A speed reduction mechanism for reducing the rotation of the rotor, A differential gear mechanism including a differential input member and distributing the rotation transmitted from the speed reduction mechanism to the differential input member to the pair of output members, the vehicle drive device comprising: The rotor, the pair of output members, and the differential gear mechanism are arranged on a first axis, The speed reduction mechanism is A first gear arranged on the first axis and connected so as to rotate integrally with the rotor, A first counter gear mechanism including a second gear meshing with the first gear and a third gear connected so as to rotate integrally with the second gear, the first counter gear mechanism being arranged on a second axis which is an axis different from the first axis, A second counter gear mechanism including a fourth gear meshing with the third gear and a fifth gear connected so as to rotate integrally with the fourth gear, the second counter gear mechanism being arranged on a third axis which is an axis different from the first axis and the second axis, A sixth gear arranged on the first axis, meshing with the fifth gear, and connected so as to rotate integrally with the differential input member, the vehicle drive device comprising:

2. The first axis, the second axis, and the third axis are parallel to each other, Taking the direction along the first axis as the axial direction and the direction perpendicular to the first axis in a top - down view as the width direction, Both the second axis and the third axis are arranged on one side in the width direction with respect to the first axis, Both the first counter gear mechanism and the second counter gear mechanism are arranged so as to overlap the rotating electrical machine in the axial direction view, and The vehicle drive device according to claim 1, wherein the first counter gear mechanism and the second counter gear mechanism are arranged so as to overlap each other in the axial direction view.

3. Taking the direction along the first axis as the axial direction, one side in the axial direction as the first axial side, and the other side in the axial direction as the second axial side, The rotor, the first gear, and the differential gear mechanism are arranged in the order described from the first axial side to the second axial side on the first axis, The third gear and the fourth gear are arranged on the second axial side with respect to the first gear and the second gear, The fifth gear and the sixth gear are arranged on the second axial side with respect to the third gear and the fourth gear, The axial arrangement region of the differential gear mechanism overlaps with the axial arrangement regions of the third gear and the fourth gear. The vehicle drive device according to claim 1 or 2.

4. The vehicle drive device further includes an inverter unit for driving and controlling the rotary electric machine. Taking the direction along the first axis as the axial direction, At least a part of the inverter unit is axially between the rotary electric machine and the sixth gear, and is arranged so as to overlap both the rotary electric machine and the sixth gear in an axial view along the axial direction. The vehicle drive device according to claim 3.

5. A case for housing the rotary electric machine, the speed reduction mechanism, and the differential gear mechanism; An oil pump for sucking and circulating the oil in the case; The vehicle drive device further includes an oil cooler for cooling the oil circulated by the oil pump. Taking the direction along the first axis as the axial direction, At least one of the first counter gear mechanism and the second counter gear mechanism is arranged so as to overlap at least one of the oil pump and the oil cooler in an axial view along the axial direction. The vehicle drive device according to claim 1 or 2.

6. An inverter unit for driving and controlling the rotary electric machine; A first heat exchange part for performing heat exchange between the inverter unit and the refrigerant; A storage part provided at the lower part of the case for storing the oil; The vehicle drive device further includes a second heat exchange part for performing heat exchange between the oil stored in the storage part and the refrigerant. The oil cooler performs heat exchange between the oil and the refrigerant. A refrigerant flow path is provided in the case and configured such that the refrigerant flows in the order of the first heat exchange part, the oil cooler, and the second heat exchange part. The refrigerant flow path A first refrigerant flow path connecting the first heat exchange part and the oil cooler; And a second refrigerant flow path connecting the oil cooler and the second heat exchange part. In the axial view, the first refrigerant flow path is arranged at a position overlapping at least one of the first counter gear mechanism and the second counter gear mechanism. In the axial view, the second refrigerant flow path is arranged at a position overlapping at least the other of the first counter gear mechanism and the second counter gear mechanism. The vehicle drive device according to claim 5.

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