Vehicle drive device

Abstract

The present application relates to a vehicle drive device. A vehicle drive device (100) includes a rotary electric machine (MG) that functions as a drive power source for a wheel (W); an input member (1) that is drivingly connected to the rotary electric machine; a pair of output members (4) that are each drivingly connected to the wheel; a differential gear mechanism (3) that distributes rotation transmitted from the rotary electric machine side to the pair of output members; a transmission gear mechanism (2) that drivingly connects the input member and the differential gear mechanism; a hydraulic pump (6) that includes a pump rotor (61) and a pump chamber (62) that houses the pump rotor, and supplies oil to at least the rotary electric machine; and a housing (9) that includes a partition (91) that divides a first housing chamber (A1) that houses the rotary electric machine in an axial direction (L), and a second housing chamber (A2) that houses the transmission gear mechanism and the differential gear mechanism, and the pump chamber is formed in the partition wall in a manner that is located between the first housing chamber and the second housing chamber in the axial direction.

Description

Technical Field

[0001] The present invention relates to a vehicle drive device having a rotary electric motor that functions as a driving force source for wheels, an input component that is driven and connected to the rotary electric motor, a pair of output components that are driven and connected to the wheels respectively, a differential gear mechanism that distributes the rotation transmitted from the rotary electric motor to the pair of output components, and a hydraulic pump that supplies oil to at least the rotary electric motor. Background Technology

[0002] An example of such a vehicle drive system is disclosed in Patent Document 1 below. Reference numerals from Patent Document 1 are cited in parentheses in the following descriptions of the "Background Art" and "Problems to be Solved by the Invention".

[0003] In the vehicle drive system of Patent Document 1, a reversing gear mechanism (22) is provided in the power transmission path between the input component (22a) connected to the rotary motor (12) and the differential gear mechanism (24). Furthermore, the pump input shaft (50) of the hydraulic pump (40) is connected to the secondary shaft (22e) of the reversing gear mechanism (22) in a manner that allows for integral rotation. Therefore, the hydraulic pump (40) is driven as the reversing gear mechanism (22) rotates.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2019-129608

[0005] In the vehicle drive unit of Patent Document 1, a hydraulic pump (40) is disposed outside a housing (18) that houses a rotary motor (12) and the like. Specifically, the pump cover (48) is joined to the outer surface of the side wall portion (36a) of the housing (18). Furthermore, a pump chamber (S3) housing the pump rotors (40a, 40b) is formed between the side wall portion (36a) and the pump cover (48).

[0006] In this structure, to prevent oil from leaking from the pump chamber (S3) to the outside of the housing (18), a sealing component and an overflow valve (56) are provided in the hydraulic pump (40). The sealing component is a component that oil-tightly seals the side wall portion (36a) between the pump cover (48) (see Patent Document 1). Figure 2 The relief valve (56) is a valve that discharges a portion of the oil supplied to the oil passage into the housing (18) when the pressure in the oil passage connected to the pump chamber (S3) becomes abnormally high. Thus, in the vehicle drive device of Patent Document 1, the hydraulic pump (40) has a complex structure.

[0007] Therefore, there is a need for a vehicle drive system that allows the hydraulic pump to be designed with a simple structure. Summary of the Invention

[0008] In view of the above, the characteristic structure of a vehicle drive system includes the following aspects:

[0009] A rotary electric motor functions as the driving force source for wheels;

[0010] The input component is connected to the aforementioned rotary motor drive;

[0011] A pair of output components, each connected to the aforementioned wheel drive;

[0012] A differential gear mechanism that distributes the rotation transmitted from the aforementioned rotary motor to a pair of the aforementioned output components;

[0013] A transmission gear mechanism that drives and connects the input component to the differential gear mechanism.

[0014] A hydraulic pump, comprising a pump rotor and a pump chamber for housing the pump rotor, and supplying oil to at least the aforementioned rotating electric motor; and

[0015] The housing contains the aforementioned rotary motor, the aforementioned input component, the aforementioned differential gear mechanism, the aforementioned transmission gear mechanism, and the aforementioned hydraulic pump.

[0016] Let the direction along the rotation axis of the aforementioned rotary motor be defined as the axial direction.

[0017] The aforementioned housing includes: a dividing wall that divides along the aforementioned axial direction to house a first housing chamber for the aforementioned rotary electric motor, and a dividing wall that divides along the aforementioned axial direction to house a second housing chamber for the aforementioned transmission gear mechanism and the aforementioned differential gear mechanism.

[0018] The pump chamber is formed in the dividing wall in such a way that it is located between the first receiving chamber and the second receiving chamber in the aforementioned axial direction.

[0019] According to this structural feature, the pump chamber of the hydraulic pump is formed by a dividing wall that divides the internal space of the housing into a first receiving chamber and a second receiving chamber. Therefore, even if oil leaks from the pump chamber, the oil only flows into the first or second receiving chamber and does not leak to the outside of the housing. Thus, according to this structural feature, without installing sealing components, relief valves, etc., in the hydraulic pump, it is possible to prevent oil discharged from the hydraulic pump from flowing to the outside of the housing. Therefore, the hydraulic pump can be designed with a simple structure. Attached Figure Description

[0020] Figure 1 This is a cross-sectional view along the axial direction of the vehicle drive unit of the embodiment.

[0021] Figure 2 This is a schematic diagram of the vehicle drive system according to the embodiment.

[0022] Figure 3 This is an enlarged view of the main components of the vehicle drive unit according to the embodiment.

[0023] Figure 4 This is a diagram showing the positional relationship of the components housed in the housing in the vehicle drive system according to the embodiment, viewed along the axial direction. Detailed Implementation

[0024] Hereinafter, the vehicle drive device 100 according to the embodiments will be described with reference to the accompanying drawings. Figure 1 as well as Figure 2 As shown, the vehicle drive unit 100 includes a rotary motor MG, an input component 1, a transmission gear mechanism 2, a differential gear mechanism 3, a pair of output components 4, and a housing 9.

[0025] In the following explanation, the direction along the rotation axis of the rotary electric machine MG will be designated as "axial direction L". Furthermore, one side of axial direction L will be designated as "first axial direction L1", and the other side as "second axial direction L2". Additionally, the direction orthogonal to the rotation axis of the rotary electric machine MG and other rotating components will be designated as "radial direction R" with each rotation axis as a reference. Moreover, when it is not necessary to distinguish which rotation axis is used as a reference, or when it is necessary to specify which rotation axis is used as a reference, it is sometimes simply referred to as "radial direction R".

[0026] The housing 9 houses the rotary motor MG, the input component 1, the transmission gear mechanism 2, and the differential gear mechanism 3. In this embodiment, the housing 9 also houses a pair of output components 4.

[0027] like Figure 1 As shown, the housing 9 includes a dividing wall 91. The dividing wall 91 is formed to divide the internal space of the housing 9. Specifically, the dividing wall 91 is formed along the axial direction L to divide a first housing chamber A1 for housing the rotary motor MG and a second housing chamber A2 for housing the transmission gear mechanism 2 and the differential gear mechanism 3. In this embodiment, the first housing chamber A1 houses not only the rotary motor MG but also a portion of the input component 1. Furthermore, the second housing chamber A2 houses not only the transmission gear mechanism 2 and the differential gear mechanism 3 but also a portion of the input component 1 and a pair of output components 4.

[0028] In this embodiment, the housing 9 further includes a first peripheral wall portion 92, a first side wall portion 93, a second peripheral wall portion 94, and a second side wall portion 95.

[0029] The first peripheral wall portion 92 is formed as a cylinder having an axis along the axial direction L. The first side wall portion 93 is formed to close the opening on the axial first side L1 of the first peripheral wall portion 92. The second peripheral wall portion 94 is formed as a cylinder having an axis along the axial direction L. The second side wall portion 95 is formed to close the opening on the axial second side L2 of the second peripheral wall portion 94. In this embodiment, the dividing wall 91 is formed to close the opening on the axial second side L2 of the first peripheral wall portion 92 and the opening on the axial first side L1 of the second peripheral wall portion 94. That is, the first peripheral wall portion 92 is formed to extend from the dividing wall 91 towards the axial first side L1, and the second peripheral wall portion 94 is formed to extend from the dividing wall 91 towards the axial second side L2. Figure 1 In the example shown, the dividing wall 91 is integrally formed with the first peripheral wall portion 92 and the second peripheral wall portion 94.

[0030] In this embodiment, the space inside the housing 9, enclosed by the dividing wall 91, the first peripheral wall portion 92, and the first side wall portion 93, is formed as a first storage chamber A1. Furthermore, the space inside the housing 9, enclosed by the dividing wall 91, the second peripheral wall portion 94, and the second side wall portion 95, is formed as a second storage chamber A2.

[0031] The rotary electric motor MG functions as the driving force source for the wheel W. The rotary electric motor MG functions as both a motor (electric motor) that receives and generates power from an electrical supply, and a generator (generator) that receives and generates power from an electrical supply. Specifically, the rotary electric motor MG is electrically connected to an energy storage device (not shown) such as a battery or capacitor. Furthermore, the rotary electric motor MG generates driving force by using the electricity stored in the energy storage device. Additionally, the rotary electric motor MG generates electricity using the driving force transmitted from the wheel W side, thereby charging the energy storage device.

[0032] The rotating electric machine MG has a stator ST and a rotor RT. The stator ST has a stator core STC fixed to a non-rotating component (here, housing 9). The rotor RT has a rotor core RTC supported so as to be rotatable relative to the stator ST, and a rotor shaft RTS integrally rotatably connected to the rotor core RTC.

[0033] In this embodiment, the rotary motor MG is a rotary excitation type rotary motor. Therefore, coils C are wound in the stator core STC such that coil ends protrude from both sides (the first axial side L1 and the second axial side L2) of the stator core STC in the axial direction L. Furthermore, a permanent magnet PM is provided in the rotor core RTC. In this embodiment, the rotary motor MG is also an inner rotor type rotary motor. Therefore, the rotor core RTC is positioned radially inner than the stator core STC. Moreover, the rotor core RTC supports the rotor shaft RTS from radially outer side R.

[0034] The rotor shaft RTS is formed to extend along the axial direction L. In this embodiment, the rotor shaft RTS is formed as a cylinder having an axis along the axial direction L. Furthermore, the rotor shaft RTS is supported by a first rotor bearing B11 and a second rotor bearing B12 disposed on a second axial side L2 closer to the first rotor bearing B11, enabling it to rotate relative to the housing 9. Figure 1 In the example shown, the axial first side L1 end of the rotor shaft RTS is supported by a first rotor bearing B11 so that it can rotate relative to the first sidewall 93 of the housing 9. Furthermore, the axial second side L2 end of the rotor shaft RTS is supported by a second rotor bearing B12 so that it can rotate relative to the second sidewall 95 of the housing 9. In this example, both the first rotor bearing B11 and the second rotor bearing B12 are ball bearings.

[0035] Input component 1 is driven and connected to the rotary motor MG. In this embodiment, input component 1 is disposed along the axial direction L, passing through the dividing wall 91 of the housing 9, and extending throughout the first storage chamber A1 and the second storage chamber A2. Furthermore, input component 1 is coaxially disposed with the rotor shaft RTS of the rotary motor MG, and is integrally rotatable with the rotor shaft RTS within the first storage chamber A1. Figure 1 In the example shown, the portion of the input component 1 on the first axial side L1 of the dividing wall 91 is positioned inside the rotor shaft RTS on the second axial side L2 of the rotor core RTC. Furthermore, these portions are interconnected by spline engagement in a manner that allows them to rotate as a single unit.

[0036] Here, in this application, "drive connection" refers to a state in which two rotating components are connected to transmit driving force, including a state in which the two rotating components are connected in a manner that allows them to rotate as a whole, or a state in which the two rotating components are connected to transmit driving force via one or more transmission components. Such transmission components include various components that transmit rotation at the same speed or at varying speeds, such as shafts, gear mechanisms, belts, chains, etc. In addition, transmission components may also include engagement devices that selectively transmit rotation and driving force, such as friction engagement devices, meshing engagement devices, etc. However, in the differential gear mechanism 3, when each rotating component is referred to as "drive connection," it means a state in which they are connected to each other without being driven by other rotating components.

[0037] In this embodiment, the input component 1 is supported by a first input bearing B21 and a second input bearing B22 disposed on a second axial side L2 relative to the first input bearing B21, enabling it to rotate relative to the housing 9. Figure 1In the example shown, a portion of the dividing wall 91 of the through-shell 9 in the input component 1 is supported by a first input bearing B21 so that it can rotate relative to the dividing wall 91. Furthermore, the end of the axial second side L2 of the input component 1 is supported by a second input bearing B22 so that it can rotate relative to the second sidewall 95 of the shell 9. In this example, both the first input bearing B21 and the second input bearing B22 are ball bearings.

[0038] The transmission gear mechanism 2 drives and connects the input component 1 and the differential gear mechanism 3. That is, the transmission gear mechanism 2 transmits the rotation from the input component 1 to the differential gear mechanism 3. In this embodiment, the transmission gear mechanism 2 includes a first gear 21 and a reversing gear mechanism 22.

[0039] The first gear 21 is disposed on the first shaft X1. Specifically, the first gear 21 is configured to rotate about the first shaft X1 as the axis of rotation. The first shaft X1 is the axis of rotation of the input component 1. As described above, in this embodiment, the input component 1 is disposed coaxially with the rotor shaft RTS of the rotary motor MG. Therefore, the first shaft X1 is disposed along the axial direction L, which is the direction along the axis of rotation of the rotary motor MG.

[0040] The first gear 21 is connected to the input component 1 in a rotating manner. Figure 1 In the example shown, the first gear 21 is integrally formed with the input component 1. Furthermore, the first gear 21 is disposed between the first input bearing B21 and the second input bearing B22 in the axial direction L.

[0041] The reversing gear mechanism 22 is disposed on a second shaft X2, which is different from the first shaft X1. The second shaft X2 is the rotation axis of the reversing gear mechanism 22. In this embodiment, the second shaft X2 is disposed parallel to the first shaft X1. That is, in this embodiment, the second shaft X2 is disposed along the axial direction L.

[0042] The reversing gear mechanism 22 includes a second gear 23 that meshes with the first gear 21, a third gear 24 that rotates integrally with the second gear 23, and a countershaft 25 that connects the second gear 23 and the third gear 24. The second gear 23, the third gear 24, and the countershaft 25 are arranged on the second shaft X2.

[0043] The second gear 23 and the third gear 24 are each connected to the countershaft 25 in a manner that allows them to rotate as a single unit. Figure 1 In the example shown, the second gear 23 is connected to the countershaft 25 via a spline engagement. Furthermore, the third gear 24 is integrally formed with the countershaft 25. Additionally, the diameter of the third gear 24 is smaller than the diameter of the second gear 23.

[0044] The secondary shaft 25 is formed to extend along the second axis X2. In this embodiment, the secondary shaft 25 is supported by a first secondary bearing B31 and a second secondary bearing B32 disposed on an axially second side L2 relative to the first secondary bearing B31, enabling it to rotate relative to the housing 9. Figure 1 In the example shown, the axial first side L1 end of the secondary shaft 25 is supported by a first secondary bearing B31, allowing it to rotate relative to the dividing wall 91 of the housing 9. Furthermore, the axial second side L2 end of the secondary shaft 25 is supported by a second secondary bearing B32, allowing it to rotate relative to the second side wall 95 of the housing 9. In this example, both the first secondary bearing B31 and the second secondary bearing B32 are tapered roller bearings.

[0045] The differential gear mechanism 3 is configured to distribute the rotation transmitted from the rotary motor MG side to a pair of output components 4. In this embodiment, the differential gear mechanism 3 includes a fourth gear 31 that meshes with the third gear 24 of the reversing gear mechanism 22. Therefore, in this embodiment, the differential gear mechanism 3 distributes the rotation of the fourth gear 31 to the pair of output components 4.

[0046] The fourth gear 31 is disposed on a third shaft X3, which is different from the first shaft X1 and the second shaft X2. The third shaft X3 is the rotation axis of the fourth gear 31. In this embodiment, the third shaft X3 is disposed parallel to both the first shaft X1 and the second shaft X2. That is, in this embodiment, the third shaft X3 is disposed along the axial direction L.

[0047] In this embodiment, the differential gear mechanism 3 further includes a differential housing 32, a pair of pinions 33, a first side gear 34, and a second side gear 35. Here, the pair of pinions 33, the first side gear 34, and the second side gear 35 are all bevel gears.

[0048] The differential housing 32 is a hollow component that houses a pair of pinions 33, a first side gear 34, and a second side gear 35. The differential housing 32 is integrally rotatably connected to the fourth gear 31. Figure 1 In the example shown, bolts are used to connect the fourth gear 31 to the differential housing 32.

[0049] In this embodiment, the differential housing 32 is supported by a first differential bearing B41 and a second differential bearing B42 disposed on the axial second side L2 of the first differential bearing B41, enabling it to rotate relative to the housing 9. In the illustrated example, the end of the differential housing 32 on the axial first side L1 is supported by the first differential bearing B41 to rotate relative to the dividing wall 91 of the housing 9. Furthermore, the end of the differential housing 32 on the axial second side L2 is supported by the second differential bearing B42 to rotate relative to the second sidewall 95 of the housing 9. In this example, both the first differential bearing B41 and the second differential bearing B42 are tapered roller bearings.

[0050] A pair of pinions 33 are arranged to face each other at a distance on a radial axis R with the third axis X3 as the reference. Moreover, the pair of pinions 33 are mounted on a pinion shaft 36 supported and rotated integrally with the differential housing 32. Each of the pair of pinions 33 is configured to be able to rotate (rotate) about the pinion shaft 36 and to rotate (revolve) about the third axis X3.

[0051] The first side gear 34 and the second side gear 35 mesh with a pair of pinions 33. The first side gear 34 and the second side gear 35 are configured to rotate about a third shaft X3. The first side gear 34 and the second side gear 35 are configured to be spaced apart from each other along the axial direction L and sandwich the pinion shaft 36. The first side gear 34 is positioned on the first side L1 axially closer than the second side gear 35.

[0052] Each of the pair of output components 4 is driven to the wheel W. In this embodiment, the pair of output components 4 are arranged side by side along the third axis X3. In the following description, the output component 4 on the first side L1 of the pair of output components 4 will be referred to as "first output component 41", and the output component 4 on the second side L2 of the pair will be referred to as "second output component 42".

[0053] In this embodiment, the second output component 42 is connected to the second side gear 35 in a rotatable manner. Figure 1 In the example shown, the second output component 42 is integrally formed with the second side gear 35. Furthermore, in this embodiment, the second output component 42 is integrally rotatably connected to the drive shaft DS on the axial second side L2. Figure 1 In the example shown, the second output component 42 is formed as a cylinder having a shaft along the axial direction L, and is disposed on the inner side of the radial direction R relative to the second side gear 35. Moreover, the drive shaft DS is inserted into the second output component 42 from the axial second side L2 toward the inner side of the radial direction R, and they are connected to each other by spline engagement.

[0054] In this embodiment, the first output component 41 is connected to the first side gear 34 in a rotatable manner. Figure 1 In the example shown, the first output component 41 is integrally formed with the first side gear 34. Furthermore, in this embodiment, the first output component 41 is connected to the drive shaft DS axially on the first side L1 via the transmission shaft 5 in a manner that allows for integral rotation. Figure 1 In the example shown, the first output component 41 is formed as a cylinder with an axis along the axial direction L, and is disposed on the inner side of the radial direction R relative to the first side gear 34. Moreover, the transmission shaft 5 is inserted into the first output component 41 from the axial first side L1 to the inner side of the radial direction R, and they are connected to each other by spline engagement.

[0055] The transmission shaft 5 is a shaft component with the third shaft X3 as its rotation axis. In this embodiment, the transmission shaft 5 is arranged along the axial direction L, passing through the dividing wall 91 of the housing 9, and extending throughout the first storage chamber A1 and the second storage chamber A2. Furthermore, the transmission shaft 5 is integrally rotatably connected to the drive shaft DS on the first side L1 along the axial direction. Figure 1 In the example shown, the portion of the transmission shaft 5 from the end face of the first axial side L1 to the center of the first axial side L1 is formed into a cylindrical shape that opens toward the first axial side L1. Furthermore, the first drive shaft DS1 is inserted into the cylindrical portion of the transmission shaft 5 from the first axial side L1 toward the radial R inside, and they are connected to each other by spline engagement.

[0056] In this embodiment, the transmission shaft 5 is supported by the output bearing B5 and is rotatable relative to the housing 9. Figure 1 In the example shown, the end of the first axial side L1 of the transmission shaft 5 is supported by the output bearing B5 so that it can rotate relative to the first sidewall 93 of the housing 9.

[0057] like Figure 1 as well as Figure 2 As shown, the vehicle drive unit 100 includes a hydraulic pump 6. The hydraulic pump 6 is housed in a housing 9. The hydraulic pump 6 is configured to supply oil to at least the rotary motor MG. In this embodiment, the hydraulic pump 6 supplies oil to the coil end of the coil C and the inner circumferential surface of the rotor shaft RTS in the rotary motor MG. Furthermore, the hydraulic pump 6 supplies oil to various bearings, gear meshing parts, etc., of the vehicle drive unit 100. That is, in this embodiment, the oil discharged from the hydraulic pump 6 is used only for cooling the rotary motor MG and lubricating various bearings, gear meshing parts, etc.

[0058] like Figure 3 As shown, the hydraulic pump 6 includes a pump rotor 61 and a pump chamber 62 for housing the pump rotor 61. In this embodiment, the hydraulic pump 6 also includes a pump cover 63 that engages with the dividing wall 91 of the housing 9, and a pump input shaft 64 that is integrally rotatably connected to the pump rotor 61.

[0059] In this embodiment, the hydraulic pump 6 is an internal gear pump. Therefore, the pump rotor 61 includes an inner rotor 611 and an outer rotor 612 disposed radially outside the inner rotor 611. The outer teeth of the outer circumferential surface of the inner rotor 611 mesh with the inner teeth formed on the inner circumferential surface of the outer rotor 612.

[0060] Pump chamber 62 is formed in the dividing wall 91 of housing 9. Furthermore, pump chamber 62 is disposed between the first receiving chamber A1 and the second receiving chamber A2 along the axial direction L. Pump chamber 62 is formed using the object surface S of the dividing wall 91 of housing 9. Object surface S is the side of the dividing wall 91 facing the axial direction L. In this embodiment, object surface S is the side of the dividing wall 91 facing the first receiving chamber A1 (here, the first axial side L1).

[0061] In this embodiment, the pump chamber 62 is formed by a recessed portion formed inwardly from the object surface S of the dividing wall 91. Specifically, the pump chamber 62 is a space enclosed by a first inner surface 9a and a second inner surface 9b of the dividing wall 91. The first inner surface 9a is formed in a cylindrical shape covering the outer peripheral surface of the outer rotor 612. The second inner surface 9b is formed in a planar shape covering the surfaces of the inner rotor 611 and the axial second side L2 of the outer rotor 612. In this embodiment, the first inner surface 9a is formed to extend from the side surface 9c of the axial first side L1 of the dividing wall 91 towards the axial second side L2. Furthermore, the second inner surface 9b is formed to extend radially inward from the end of the axial second side L2 of the first inner surface 9a. In this embodiment, the second inner surface 9b and the first side surface 9c correspond to the object surface S. In addition, in this example, the axial dimension L of the first inner surface 9a is slightly larger than the axial dimension L of the outer rotor 612.

[0062] In this way, the pump chamber 62 of the hydraulic pump 6 is formed on the dividing wall 91 that divides the internal space of the housing 9 into a first receiving chamber A1 and a second receiving chamber A2. Therefore, even if oil leaks from the pump chamber 62, the oil will only flow into the first receiving chamber A1 or the second receiving chamber A2, and will not leak to the outside of the housing 9. Thus, according to this structure, the leakage of oil discharged from the hydraulic pump 6 to the outside of the housing 9 can be avoided without the need to install sealing components, relief valves, etc. in the hydraulic pump 6. Therefore, the hydraulic pump 6 can be designed with a simple structure.

[0063] Furthermore, as mentioned above, in this embodiment, the oil discharged from the hydraulic pump 6 is used only for cooling the rotary motor MG and lubricating various bearings, gear meshing parts, etc. Here, if the oil discharged from the hydraulic pump 6 is used to control the engagement device, in a structure without the aforementioned sealing components, relief valves, etc., there is a possibility that the hydraulic pressure used to control the engagement device cannot be adequately supplied. However, in this embodiment, the oil discharged from the hydraulic pump 6 is not used to control the engagement device, so even if oil leaks from the pump chamber 62, it will not affect the vehicle's operation.

[0064] In this embodiment, the discharge port 6a and the suction port (not shown) of the hydraulic pump 6 are formed to open toward the second inner surface 9b. The discharge port 6a is a hole for the pump rotor 61 to discharge oil to the outside of the pump chamber 62, and is connected to the discharge oil passage (here, the first oil passage P1 described later). The suction port is a hole for the pump rotor 61 to draw oil from the outside of the pump chamber 62, and is connected to the suction oil passage.

[0065] The pump cover 63 is engaged with the dividing wall 91 in a manner that it is opposed to the object surface S along the axial direction L. Moreover, a pump chamber 62 is formed between the pump cover 63 and the dividing wall 91 along the axial direction L. In this embodiment, the pump cover 63 is engaged with the dividing wall 91 from the first axial side L1 in a manner that it covers the pump rotor 61 housed in the pump chamber 62 formed by the first inner surface 9a and the second inner surface 9b of the dividing wall 91.

[0066] Thus, in this embodiment, the hydraulic pump 6 also includes a pump cover 63 that engages with the dividing wall 91.

[0067] Pump chamber 62 is formed between the dividing wall 91 in the axial direction L and the pump cover 63.

[0068] According to this structure, by engaging the pump cover 63 with the partition wall 91 of the housing 9, a portion of the partition wall 91 can be used to properly form the pump chamber 62. This reduces the amount of oil leaking from the pump chamber 62. Therefore, it prevents oil discharged from the hydraulic pump 6 from flowing out of the housing 9, and allows for a simpler structure for the hydraulic pump 6.

[0069] The pump input shaft 64 is the input component of the hydraulic pump 6. In this embodiment, the pump input shaft 64 is configured to pass through the dividing wall 91 along the axial direction L. That is, in this embodiment, the pump input shaft 64 is configured to extend throughout the first receiving chamber A1 and the second receiving chamber A2. Moreover, in this embodiment, the pump input shaft 64 is driven to the shaft of the transmission gear mechanism 2 within the second receiving chamber A2. Here, the pump input shaft 64 is disposed on the second shaft X2 and is connected to the auxiliary shaft 25 in an integral rotatable manner. In the illustrated example, the portion of the pump input shaft 64 that protrudes from the dividing wall 91 toward the axial second side L2 is inserted into an opening formed such that it is recessed from the end face of the auxiliary shaft 25 toward the axial second side L2. Furthermore, they are connected to each other by spline engagement.

[0070] Thus, in this embodiment, the hydraulic pump 6 also includes a pump input shaft 64 that is integrally rotatably connected to the pump rotor 61.

[0071] The pump input shaft 64 is configured to pass through the dividing wall 91 along the axial direction L, and is driven to connect with the transmission gear mechanism 2 in the second receiving chamber A2.

[0072] According to this structure, the pump input shaft 64 can be supported so that it can rotate relative to the dividing wall 91 of the housing 9, and the pump rotor 61 can be driven to rotate appropriately by means of the rotation of the transmission gear mechanism 2.

[0073] Furthermore, in this embodiment, the transmission gear mechanism 2 includes: a first gear 21 disposed on a first shaft X1, which serves as the rotation axis of the input component 1, and connected to the input component 1 in a manner that allows it to rotate integrally; and a reversing gear mechanism 22 disposed on a second shaft X2, which is different from the first shaft X1.

[0074] The reversing gear mechanism 22 includes: a second gear 23 that meshes with the first gear 21, a third gear 24 that rotates integrally with the second gear 23, and a countershaft 25 that connects the second gear 23 and the third gear 24.

[0075] The differential gear mechanism 3 includes a fourth gear 31 located on a third shaft X3, which is different from the first shaft X1 and the second shaft X2, and meshes with the third gear 24.

[0076] The hydraulic pump 6 also has a pump input shaft 64 that is integrally rotatably connected to the pump rotor 61. The pump input shaft 64 is configured on the second shaft X2 and integrally rotatably connected to the auxiliary shaft 25.

[0077] In this structure, the rotational speed of the reversing gear mechanism 22 is typically lower than the rotational speed of the rotary motor MG. Therefore, as described above, the structure that drives the hydraulic pump 6 via the rotation of the secondary shaft 25 reduces the rotational speed of the pump rotor 61 compared to the structure that drives the hydraulic pump 6 via the rotary motor MG. Consequently, energy loss caused by the high-speed rotation of the hydraulic pump 6 can be minimized, thereby improving the energy efficiency of the vehicle drive unit 100.

[0078] In this embodiment, the first oil passage P1, the second oil passage P2, the third oil passage P3 and the fourth oil passage P4 are formed in the dividing wall 91 of the housing 9.

[0079] The first oil passage P1 is formed inside the partition wall 91 in communication with the pump chamber 62. The second oil passage P2 is formed to connect the first oil passage P1 and the third oil passage P3. In this embodiment, the second oil passage P2 is formed to extend along the axial direction L from the first oil passage P1 to the side of the partition wall 91 on the axial second side L2, i.e., the second side 9d. The third oil passage P3 is formed to connect the second oil passage P2 and the fourth oil passage P4. In this embodiment, the third oil passage P3 is formed between the second side 9d of the partition wall 91 and the first auxiliary bearing B31 and the auxiliary shaft 25 on the axial direction L. The fourth oil passage P4 is formed to connect the third oil passage P3 to the second receiving chamber A2. In this embodiment, the fourth oil passage P4 is formed in the cylindrical portion of the partition wall 91 that supports the first auxiliary bearing B31, with an opening toward the second receiving chamber A2.

[0080] Here, the flow of oil during the forward movement of a vehicle equipped with the vehicle drive unit 100 of this embodiment will be described. In this embodiment, when the vehicle is moving forward, if the hydraulic pump 6 is driven along with the rotation of the countershaft 25, the pump rotor 61 rotates in the forward direction (the direction of rotation when the vehicle is moving forward). As a result, oil is drawn from the storage section provided in the housing 9 through the suction oil passage (not shown) and the aforementioned suction hole into the pump chamber 62, and discharged from the discharge hole 6a into the first oil passage P1. A portion of the oil discharged into the first oil passage P1 flows through the second oil passage P2 to the third oil passage P3. The oil flowing into the third oil passage P3 lubricates the first secondary bearing B31 constituting the third oil passage P3, then lubricates other components and returns to the storage section. Thus, when the vehicle is moving forward, the pump rotor 61 is always in a lubricated state because oil is supplied to the pump chamber 62.

[0081] The flow of oil during reverse travel of a vehicle equipped with the vehicle drive unit 100 of this embodiment will be explained. When the vehicle is traveling in reverse, the pump rotor 61 rotates in the reverse direction (opposite to the forward direction), thus the flow of oil generated by the hydraulic pump 6 is reversed. Therefore, oil is not drawn from the storage section provided in the housing 9 to the pump chamber 62. However, in this embodiment, the fourth gear 31 of the differential gear mechanism 3 is configured to lift the oil stored inside the housing 9. Furthermore, it is configured such that, at least when the pump rotor 61 rotates in the reverse direction, the oil lifted by the fourth gear 31 is supplied to the third oil passage P3 through the fourth oil passage P4 opening toward the second storage chamber A2. Specifically, the opening of the fourth oil passage P4 is configured to be located in the passage of the oil lifted by the fourth gear 31. Thus, the oil supplied to the third oil passage P3 through the fourth oil passage P4 is drawn toward the pump chamber 62 through the second oil passage P2 and the first oil passage P1 as the pump rotor 61 rotates in the reverse direction (the direction of rotation when the vehicle is traveling forward). Figure 3(The dashed arrow in the diagram). Thus, even when the vehicle is moving backward, oil is supplied to the pump chamber 62, so the pump rotor 61 is always lubricated. Furthermore, in this embodiment, to facilitate the supply of oil lifted by the fourth gear 31 to the fourth oil passage P4, the fourth oil passage P4 is opened at least upwards within the second receiving chamber A2. Figure 3 In the example shown, the fourth oil passage P4 is located inside the second receiving chamber A2, facing upwards and opening axially to the second side L2.

[0082] Thus, when the vehicle equipped with the vehicle drive unit 100 of this embodiment is moving forward, the pump rotor 61 is lubricated because oil is drawn from the storage section of the housing 9 to the pump chamber 62. On the other hand, when the vehicle equipped with the vehicle drive unit 100 of this embodiment is moving backward, the oil lifted by the fourth gear 31 is supplied to the pump chamber 62 in sequence through the fourth oil passage P4, the third oil passage P3, the second oil passage P2, and the first oil passage P1, so the pump rotor 61 is also lubricated. Thus, in this embodiment, the pump rotor 61 can be properly lubricated regardless of the driving state of the vehicle equipped with the vehicle drive unit 100. Furthermore, in this embodiment, the first oil passage P1, the second oil passage P2, the third oil passage P3, and the fourth oil passage P4 function as "supply oil passages P" for supplying the oil lifted by the fourth gear 31 to the pump chamber 62.

[0083] Thus, in this embodiment, the fourth gear 31 is configured to lift the oil stored inside the housing 9.

[0084] When the hydraulic pump 6 supplies oil to the rotary motor MG, the rotation direction of the pump rotor 61 is defined as the forward rotation direction, and the opposite direction of this forward rotation direction is defined as the reverse rotation direction.

[0085] The vehicle drive unit 100 has a supply oil passage P that supplies oil to the pump chamber 62 by the oil lifted by the fourth gear 31 at least when the pump rotor 61 rotates in the reverse direction.

[0086] According to this structure, when the pump rotor 61 rotates in the reverse direction, that is, when the vehicle equipped with the vehicle drive unit 100 is moving backward, the oil lifted by the fourth gear 31 is supplied to the pump chamber 62 via the oil supply passage P. Here, when the pump rotor 61 rotates in the forward direction, that is, when the vehicle equipped with the vehicle drive unit 100 is moving forward, the oil stored inside the housing 9 is drawn in and supplied to the pump chamber 62 along with the rotation of the pump rotor 61. Therefore, according to this structure, the pump rotor 61 can be properly lubricated regardless of the driving state of the vehicle equipped with the vehicle drive unit 100.

[0087] The following describes the positional relationships of the components housed in the casing 9 when viewed axially along axis L. Furthermore, Figure 4 The reference numeral "V" in the attached figure indicates the vertical direction of the vehicle drive unit 100 mounted on a vehicle.

[0088] like Figure 4 As shown, in this embodiment, a second axis X2 is disposed above both the first axis X1 and the third axis X3. In this example, the first axis X1 is disposed above the third axis X3, and the second axis X2 is disposed above the first axis X1.

[0089] [Other Implementation Methods]

[0090] (1) In the above embodiment, the structure of the pump chamber 62 formed by a recess formed in the object surface S of the dividing wall 91 was described as an example. However, it is not limited to that structure. The pump chamber 62 may also be formed by both the recess formed in the object surface S of the dividing wall 91 and the recess formed in the surface of the pump cover 63 opposite to the object surface S. Alternatively, the above-mentioned recess may not be formed in the dividing wall 91, and the pump chamber 62 may also be formed by the recess formed in the surface of the pump cover 63 opposite to the object surface S.

[0091] (2) In the above embodiment, the structure described is exemplified by a transmission gear mechanism 2 having a reversing gear mechanism 22, and the pump input shaft 64 being integrally rotatably connected to the secondary shaft 25 of the reversing gear mechanism 22. However, the structure is not limited to that. For example, if the transmission gear mechanism 2 has multiple shafts, the pump input shaft 64 may be integrally rotatably connected to any one of the multiple shafts. Alternatively, the pump input shaft 64 may not be integrally connected to the shaft of the transmission gear mechanism 2, for example, it may be integrally rotatably connected to the input component 1.

[0092] (3) In the above embodiment, the example described is that the object surface S is the surface of the dividing wall 91 facing the first storage chamber A1, and the pump input shaft 64 is configured to penetrate the dividing wall 91 along the axial direction L. However, it is not limited to that structure. The object surface S may also be the surface of the dividing wall 91 facing the second storage chamber A2, and the pump input shaft 64 may also be configured not to penetrate the dividing wall 91 along the axial direction L.

[0093] (4) In the above embodiment, the structure in which the second axis X2 is disposed above both the first axis X1 and the third axis X3 has been described as an example. However, it is not limited to that structure, and the second axis X2 may also be disposed below at least one of the first axis X1 and the third axis X3.

[0094] (5) In the above embodiment, an example of a structure in which the dividing wall 91 is integrally formed with the first peripheral wall portion 92 and the second peripheral wall portion 94 has been described. However, the structure is not limited to that; the dividing wall 91 may also be composed of components different from both the first peripheral wall portion 92 and the second peripheral wall portion 94, and fixed to them by fastening components such as bolts. Furthermore, in the above embodiment, an example of a structure in which the first peripheral wall portion 92 and the second peripheral wall portion 94 are integrally formed has been described. However, the structure is not limited to that; the first peripheral wall portion 92 and the second peripheral wall portion 94 may also be composed of different components. In this case, the dividing wall 91 may be integrally formed with either the first peripheral wall portion 92 or the second peripheral wall portion 94, or it may be composed of different components.

[0095] (6) Furthermore, the structures disclosed in the above embodiments can be combined with structures disclosed in other embodiments, provided that they do not create contradictions. Regarding other structures, the embodiments disclosed in this specification are merely illustrative in all respects. Therefore, various modifications can be appropriately made without departing from the spirit of the invention.

[0096] [Summary of the above embodiments]

[0097] The following is a summary of the vehicle drive unit (100) described above.

[0098] The vehicle drive unit (100) includes:

[0099] The rotating motor (MG) functions as the driving force source for the wheel (W);

[0100] Input component (1), which is connected to the aforementioned rotary motor (MG) drive;

[0101] A pair of output components (4) are respectively connected to the aforementioned wheel (W) drive;

[0102] The differential gear mechanism (3) distributes the rotation transmitted from the rotary motor (MG) to a pair of output components (4);

[0103] The transmission gear mechanism (2) drives and connects the input component (1) to the differential gear mechanism (3);

[0104] A hydraulic pump (6) having a pump rotor (61) and a pump chamber (62) housing the pump rotor (61), and supplying oil to at least the aforementioned rotary electric motor (MG); and

[0105] The housing (9) houses the rotary motor (MG), the input component (1), the differential gear mechanism (3), the transmission gear mechanism (2), and the hydraulic pump (6).

[0106] Let the direction along the rotation axis of the aforementioned rotary motor (MG) be defined as the axial direction (L).

[0107] The aforementioned housing (9) includes: a dividing wall (91) that divides along the aforementioned axial direction (L) to house the aforementioned rotary motor (MG) and a second housing (A2) to house the aforementioned transmission gear mechanism (2) and the aforementioned differential gear mechanism (3).

[0108] The pump chamber (62) is formed on the dividing wall (91) in such a way that it is located between the first receiving chamber (A1) and the second receiving chamber (A2) on the axial direction (L).

[0109] According to this structure, the pump chamber (62) of the hydraulic pump (6) is formed on the dividing wall (91) that divides the internal space of the housing (9) into a first receiving chamber (A1) and a second receiving chamber (A2). Therefore, even if oil leaks from the pump chamber (62), the oil will only flow into the first receiving chamber (A1) or the second receiving chamber (A2) and will not leak to the outside of the housing (9). Thus, according to this structure, without installing sealing components, relief valves, etc. in the hydraulic pump (6), it is possible to prevent the oil discharged from the hydraulic pump (6) from flowing to the outside of the housing (9). Therefore, the hydraulic pump (6) can be designed with a simple structure.

[0110] Here, preferably, the hydraulic pump (6) also includes a pump cover (63) that engages with the dividing wall (91).

[0111] The pump chamber (62) is formed between the dividing wall (91) and the pump cover (63) on the axial direction (L).

[0112] According to this structure, by joining the pump cover (63) to the partition wall (91) of the housing (9), a portion of the partition wall (91) can be used to properly form the pump chamber (62). This allows for a reduction in the amount of oil leaking from the pump chamber (62). Therefore, it is possible to prevent oil discharged from the hydraulic pump (6) from flowing outside the housing (9), and the hydraulic pump (6) can be designed with a simpler structure.

[0113] Furthermore, the hydraulic pump (6) preferably also includes a pump input shaft (64) that is integrally rotatably connected to the pump rotor (61).

[0114] The pump input shaft (64) is configured to pass through the dividing wall (91) along the axial direction (L) and be driven to the shaft of the transmission gear mechanism (2) in the second receiving chamber (A2).

[0115] According to this structure, the pump input shaft (64) can be supported so that it can rotate relative to the dividing wall (91) of the housing (9), and the pump rotor (61) can be rotated appropriately by means of the rotation of the transmission gear mechanism (2).

[0116] Furthermore, the aforementioned transmission gear mechanism (2) preferably includes: a first gear (21) disposed on a first shaft (X1) which serves as the rotation axis of the aforementioned input component (1) and connected to the aforementioned input component (1) in a manner that allows for integral rotation; and a reversing gear mechanism (22) disposed on a second shaft (X2) different from the aforementioned first shaft (X1).

[0117] The aforementioned reversing gear mechanism (22) includes: a second gear (23) meshing with the first gear (21), a third gear (24) rotating integrally with the second gear (23), and a countershaft (25) connecting the second gear (23) and the third gear (24).

[0118] The differential gear mechanism (3) described above includes: a third shaft (X3) disposed on a different shaft from the first shaft (X1) and the second shaft (X2), and a fourth gear (31) meshing with the third gear (24).

[0119] The aforementioned hydraulic pump (6) also includes a pump input shaft (64) that is integrally rotatably connected to the aforementioned pump rotor (61).

[0120] The pump input shaft (64) is mounted on the second shaft (X2) and is connected to the auxiliary shaft (25) in a rotating manner.

[0121] In such a structure, the rotational speed of the reversing gear mechanism (22) is typically lower than that of the rotary motor (MG). Therefore, as described above, the structure that drives the hydraulic pump (6) by rotating the secondary shaft (25) reduces the rotational speed of the pump rotor (61) compared to the structure that drives the hydraulic pump (6) by rotating the rotary motor (MG). Consequently, the energy loss caused by the high-speed rotation of the hydraulic pump (6) can be minimized, thereby improving the energy efficiency of the vehicle drive unit (100).

[0122] Preferably, in the structure where the transmission gear mechanism (2) includes the first gear (21) and the reversing gear mechanism (22),

[0123] The aforementioned fourth gear (31) is configured to lift the oil stored inside the aforementioned housing (9).

[0124] When the hydraulic pump (6) supplies oil to the rotary motor (MG), the rotation direction of the pump rotor (61) is defined as the forward rotation direction, and the direction opposite to the forward rotation direction is defined as the reverse rotation direction.

[0125] It is equipped with an oil supply passage (P) that supplies oil to the pump chamber (62) by the oil lifted by the fourth gear (31) at least when the pump rotor (61) rotates in the reverse direction.

[0126] According to this structure, when the pump rotor (61) rotates in the reverse direction, that is, when the vehicle equipped with the vehicle drive unit (100) is moving backward, the oil lifted by the fourth gear (31) is supplied to the pump chamber (62) via the oil supply passage (P). Here, when the pump rotor (61) rotates in the forward direction, that is, when the vehicle equipped with the vehicle drive unit (100) is moving forward, the oil stored inside the housing (9) is drawn in and supplied to the pump chamber (62) along with the rotation of the pump rotor (61). Therefore, according to this structure, the pump rotor (61) can be properly lubricated regardless of the driving state of the vehicle equipped with the vehicle drive unit (100).

[0127] Industrial applications

[0128] The technology of the present invention can be used in a vehicle drive device having a rotating electric motor that functions as a driving force source for wheels, an input component that is driven and connected to the rotating electric motor, a pair of output components that are driven and connected to the wheels respectively, a differential gear mechanism that distributes the rotation transmitted from the rotating electric motor side to the pair of output components, and a hydraulic pump that supplies oil to the rotating electric motor at least.

[0129] Explanation of reference numerals in the attached figures

[0130] 100: Vehicle drive unit; 1: Input component; 2: Transmission gear mechanism; 3: Differential gear mechanism; 4: Output component; 6: Hydraulic pump; 61: Pump rotor; 62: Pump chamber; 9: Housing; 91: Dividing wall; A1: First storage chamber; A2: Second storage chamber; MG: Rotary motor; W: Wheel; L: Axial axis.

Claims

1. A drive device for a vehicle, comprising: an electric rotating machine that functions as a drive power source for a wheel; an input member that is drivingly connected to the electric rotating machine; a pair of output members that are each drivingly connected to the wheel; a differential gear mechanism that distributes rotation transmitted from the electric rotating machine side to the pair of output members; a transmission gear mechanism that drivingly connects the input member and the differential gear mechanism; a hydraulic pump that includes a pump rotor and a pump chamber that houses the pump rotor, and supplies oil to the electric rotating machine, a bearing, or a gear meshing portion; and a housing that houses the electric rotating machine, the input member, the differential gear mechanism, the transmission gear mechanism, and the hydraulic pump, wherein an axial direction along a rotational axis of the electric rotating machine is defined as an axial direction, the housing includes a partition wall that divides a first housing chamber that houses the electric rotating machine and a second housing chamber that houses the transmission gear mechanism and the differential gear mechanism in the axial direction, the pump chamber is formed in the partition wall between the first housing chamber and the second housing chamber in the axial direction, the hydraulic pump further includes a pump input shaft that is connected to the pump rotor so as to rotate integrally with the pump rotor, and the pump input shaft is disposed so as to pass through the partition wall in the axial direction and be drivingly connected to a shaft of the transmission gear mechanism in the second housing chamber.

2. The drive device for a vehicle according to claim 1, wherein the hydraulic pump further includes a pump cover that is joined to the partition wall from an axial first side (LI), and the pump chamber is formed between the partition wall and the pump cover in the axial direction.

3. The drive device for a vehicle according to claim 1 or 2, wherein the transmission gear mechanism includes a first gear that is disposed on a first shaft that is a rotational axis of the input member and is connected to the input member so as to rotate integrally with the input member, and a reverse gear mechanism that is disposed on a second shaft that is different from the first shaft, the reverse gear mechanism includes a second gear that is meshed with the first gear, a third gear that rotates integrally with the second gear, and a lay shaft that connects the second gear and the third gear, the differential gear mechanism includes a fourth gear that is disposed on a third shaft that is different from the first shaft and the second shaft and is meshed with the third gear, the hydraulic pump further includes a pump input shaft that is connected to the pump rotor so as to rotate integrally with the pump rotor, and the pump input shaft is disposed on the second shaft and is connected to the lay shaft so as to rotate integrally with the lay shaft.

4. The drive device for a vehicle according to claim 3, wherein the fourth gear is disposed so as to lift up oil stored inside the housing, a rotational direction of the pump rotor in a case where the hydraulic pump supplies oil to the electric rotating machine is defined as a forward rotation direction, and a direction opposite to the forward rotation direction is defined as a reverse rotation direction, and the hydraulic pump includes a supply oil passage that supplies oil lifted up by the fourth gear to the pump chamber at least in a case where the pump rotor rotates in the reverse rotation direction. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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