Vehicle drive device

Abstract

A vehicle drive unit is provided. The vehicle drive unit (100) includes: a rotary motor (1), an input shaft (2), a pair of output components (3), a reduction mechanism (4), a differential gear mechanism (5), and a housing (9). The reduction mechanism (4) reduces the rotation of the rotary motor (1). The input shaft (2) is integrally connected to the rotary motor (1) and rotates. The differential gear mechanism (5) includes a differential input component (51) and distributes the rotation transmitted from the reduction mechanism (4) to the differential input component to the pair of output components (3). The differential input component (51) is rotatable relative to the housing (9) by being supported via a first bearing (B31). The input shaft (2) is rotatable relative to the differential input component (51) by being supported via a second bearing (B12). The first bearing (B31) is configured to overlap with the second bearing (B12) when viewed radially (R).

Description

Technical Field

[0001] The present invention relates to a drive device for a vehicle, comprising a rotary motor having a rotor and a deceleration mechanism for reducing the rotation of the rotor. Background Technology

[0002] An example of such a drive system for a vehicle is disclosed in Patent Document 1 below. In the following description of the background art, reference numerals and names from Patent Document 1 will be enclosed in parentheses.

[0003] The vehicle drive unit (rear drive axle 10) described in Patent Document 1 includes: a rotary motor (electric motor 1), a reduction gear mechanism (first reduction gear pair 14, second reduction gear pair 16), a differential gear mechanism (differential mechanism 17), a housing (20) housing these components, and a pair of output components (a pair of rear axles 18). In this vehicle drive unit (rear drive axle 10), the rotary motor (electric motor 1) and the differential gear mechanism (differential mechanism 17) are arranged on the same axis, while the intermediate gear mechanism constituting the reduction gear mechanism (first reduction gear pair 14, second reduction gear pair 16) is arranged on a different axis from the rotary motor (electric motor 1) and the differential gear mechanism (differential mechanism 17). The rotation of the rotor (11a) of the rotary motor (electric motor 1) is reduced by the reduction gear mechanism (first reduction gear pair 14, second reduction gear pair 16) and transmitted to the pair of output components (a pair of rear axles 18) via the differential gear mechanism (differential mechanism 17).

[0004] In the vehicle drive unit (rear drive axle 10) described in Patent Document 1, the rotor (11a) of the rotary motor (motor 1) is rotatable by a housing (20) via an input shaft (output shaft 12) that rotates integrally with the rotor (11a) and a pair of bearings (output shaft bearing 21). Furthermore, the differential gear mechanism (differential mechanism 17) is rotatable by a housing (20) via a pair of bearings (27).

[0005] Patent Document 1: Japanese Patent Application Publication No. 2014-025491

[0006] In the vehicle drive unit (rear drive axle 10) described in Patent Document 1, since the rotary motor (motor 1) and the differential gear mechanism (differential mechanism 17) are arranged on the same axis, the bearings supporting the rotor (11a) (output shaft bearing 21) and the bearings supporting the differential gear mechanism (differential mechanism 17) are arranged side by side axially on the same axis. Therefore, space is required in the axial direction for arranging these bearings (output shaft bearing 21, bearing 17), which correspondingly tends to lead to an increase in the axial size of the vehicle drive unit (rear drive axle 10). Summary of the Invention

[0007] Therefore, it is desirable to realize a vehicle drive unit that is easy to miniaturize in axial dimensions.

[0008] The characteristic structure of the drive unit for this vehicle, in view of the above, comprises: a rotary motor having a rotor; an input shaft integrally connected to the rotor for rotation; a pair of output components, each connected to a wheel for drive; a reduction mechanism for reducing the rotation of the input shaft; a differential gear mechanism having a differential input component and distributing the rotation transmitted from the reduction mechanism to the differential input component to the pair of output components; and a housing housing the rotary motor, the input shaft, the reduction mechanism, and the differential gear mechanism, wherein the rotor, the input shaft, the pair of output components, and the differential gear mechanism are arranged on a first shaft center, and the reduction mechanism includes: a first gear arranged on the first shaft center and connected to the input shaft for drive. The gear mechanism comprises a second gear meshing with the first gear and a third gear connected to the second gear and rotating integrally, and is disposed on a second axis that is not aligned with the first axis; and a fourth gear disposed on the first axis, meshing with the third gear and rotating integrally with the differential input component, the differential input component being rotatable relative to the housing via a first bearing, and the input shaft being rotatable relative to the differential input component via a second bearing, with the direction orthogonal to the first axis as the radial direction, and the first bearing and the second bearing being arranged to overlap when viewed radially along the radial direction.

[0009] According to this characteristic structure, the differential input component employing a differential gear mechanism is supported by the housing via a first bearing, and the input shaft is supported by the differential input component via a second bearing. This structure allows the first and second bearings to be arranged in an overlapping configuration when viewed radially, while avoiding a more complex housing shape. Furthermore, by arranging the first and second bearings in an overlapping configuration when viewed radially, compared to arranging these components in a non-overlapping positional relationship when viewed radially, it is easier to achieve miniaturization of the axial dimensions of the vehicle drive unit. Attached Figure Description

[0010] Figure 1 This is a cross-sectional view of the vehicle drive unit according to the embodiment.

[0011] Figure 2 This is a frame diagram of the vehicle drive unit involved in the implementation method.

[0012] Figure 3 yes Figure 1 Enlarged view of the reduction mechanism and differential gear mechanism shown. Detailed Implementation

[0013] Reference Figures 1 to 3 The vehicle drive unit 100 according to the embodiment will be described below. Figure 1 and Figure 2 As shown, the vehicle drive unit 100 includes: a rotary motor 1 with a rotor 12, an input shaft 2 connected to the rotor 12 in a manner that rotates integrally with the rotor 12, a pair of output components 3 respectively drivenly connected to the wheels W, a reduction mechanism 4, a differential gear mechanism 5, and a housing 9. The reduction mechanism 4 and the differential gear mechanism 5 drively connect the input shaft 2 and the output components 3. The housing 9 houses the rotary motor 1, the input shaft 2, the reduction mechanism 4, and the differential gear mechanism 5. In this embodiment, the rotor 12 of the rotary motor 1, the input shaft 2, the pair of output components 3, and the differential gear mechanism 5 are arranged on the same axis (first axis X1).

[0014] In this application, "drive connection" refers to a state in which two rotating elements are connected in a manner capable of transmitting driving force, including a state in which the two rotating elements are connected in a manner capable of rotating as a whole, or a state in which the two rotating elements are connected via one or more transmission components in a manner capable of transmitting driving force. Such transmission components include various components that transmit rotation at constant or variable speeds, such as shafts, gear mechanisms, belts, chains, etc. Furthermore, transmission components may also include engagement devices that selectively transmit rotation and driving force, such as friction engagement devices, meshing engagement devices, etc.

[0015] In the following description, the direction along the first axis X1 will be referred to as the "axial direction L" of the vehicle drive unit 100. The direction orthogonal to the first axis X1 will be referred to as the "radial direction R". Furthermore, one side of the axial direction L will be referred to as the first axial side L1, and the other side of the axial direction L will be referred to as the second axial side L2.

[0016] The rotary motor 1 functions as the driving force source for the wheel W. The rotary motor 1 functions as both a motor (electric motor) that receives and generates power from a power supply and a generator that receives and generates power from a power supply. Specifically, the rotary motor 1 is electrically connected to an energy storage device (not shown) such as a battery or capacitor. Furthermore, the rotary motor 1 generates driving force by utilizing the electricity stored in the energy storage device. In addition, the rotary motor 1 generates electricity using the driving force transmitted from the wheel W side, thereby charging the energy storage device.

[0017] The rotary electric motor 1 also includes a stator 11. The stator 11 has a cylindrical stator core 111. The stator core 111 is fixed to a non-rotating component. In this embodiment, the stator core 111 is fixed to a housing 9, which is a non-rotating component. The rotor 12 of the rotary electric motor 1 has a cylindrical rotor core 121. The rotor core 121 is supported so that it is rotatable relative to the stator core 111.

[0018] The reduction mechanism 4 reduces the rotational speed of the input shaft 2. The reduction mechanism 4 includes: a first gear 4A integrally rotated with the input shaft 2; an intermediate gear mechanism 41 including a second gear 4B and a third gear 4C; and a fourth gear 4D. The first gear 4A is disposed on a first shaft X1. The intermediate gear mechanism 41 is drivenly connected to the first gear 4A via the second gear 4B. Furthermore, the intermediate gear mechanism 41 is disposed on a second shaft X2 that is on a different axis from the first shaft X1. In this example, the first shaft X1 and the second shaft X2 are parallel to each other. In this embodiment, the fourth gear 4D is drivenly connected to the differential input component 51. Figure 1 The fourth gear 4D shown is configured on the first shaft X1.

[0019] In this embodiment, such as Figure 1 and Figure 2 As shown, the first gear 4A is connected to the rotor 12 via the input shaft 2. The input shaft 2 includes a shaft component that is integrally rotated with the rotor 12. The connection structure between the input shaft 2 and the rotor 12 in this embodiment will be described below.

[0020] The intermediate gear mechanism 41 includes a second gear 4B and a third gear 4C. The second gear 4B meshes with a first gear 4A. The third gear 4C is integrally connected to the second gear 4B and rotates together. In this embodiment, the third gear 4C is connected to the second gear 4B via a countershaft 411. The countershaft 411 includes a shaft member that is integrally connected to and rotates with both the second gear 4B and the third gear 4C. Figure 1 and Figure 3 In the example shown, the secondary shaft 411 is formed to extend along the second axis X2. At least one of the second gear 4B or the third gear 4C is a component independent of the secondary shaft 411, but is integrally connected to the secondary shaft 411 for rotation. Furthermore, the other of the second gear 4B or the third gear 4C is integrally formed with the secondary shaft 411. In this example, the second gear 4B is a component independent of the secondary shaft 411, and the third gear 4C is integrally formed with the secondary shaft 411.

[0021] Here, "independent component" refers to each independent component that separates from the component state before becoming the final product, including both components that can be separated in the final product state and components that are inseparably joined together in the final product state. Furthermore, it includes both cases where multiple components constituting a "independent component" are made of the same material and cases where they are made of different materials.

[0022] exist Figure 1In the example shown, the second gear 4B is formed with a diameter larger than that of the first gear 4A. Furthermore, although not shown, the second gear 4B has more teeth than the first gear 4A. Therefore, if the rotation of the first gear 4A is transmitted to the second gear 4B, the rotational speed of the countershaft 411 is lower than the rotational speed of the first gear 4A.

[0023] The fourth gear, 4D, meshes with the third gear, 4C. Figure 1 In the example shown, the fourth gear 4D is formed with a larger diameter than the third gear 4C. Furthermore, although not shown, the fourth gear 4D has more teeth than the third gear 4C. Additionally, in... Figure 1 In the example shown, the third gear 4C is formed with a smaller diameter than the second gear 4B. Therefore, when viewed in the axial direction L, a fourth gear 4D (described later) that meshes with the third gear 4C can also be arranged at a position overlapping with the second gear 4B. Therefore, even without increasing the radial dimension of the vehicle drive unit 100, it is easy to form the fourth gear 4D with a large diameter.

[0024] like Figure 1 As shown, the differential gear mechanism 5 includes a differential input component 51. The differential gear mechanism 5 distributes the rotation transmitted from the reduction mechanism 4 to the differential input component 51 to a pair of output components 3. In this embodiment, the fourth gear 4D is integrally connected to the differential input component 51 and rotates as a single unit.

[0025] In this embodiment, the rotor 12, the first gear 4A, a pair of output components 3, 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 shaft X1. Furthermore, the radially arranged area of ​​the differential gear mechanism 5 overlaps with the radially arranged area of ​​the second gear 4B. Therefore, compared to a situation where the radially arranged area of ​​the differential gear mechanism 5 does not overlap with the radially arranged area of ​​the second gear 4B, the overall radial dimension of the vehicle drive unit 100 is smaller.

[0026] Here, regarding the configuration of the two elements, "overlapping when viewed from a specific direction" means that when an imaginary line parallel to its line of sight is moved along directions orthogonal to the imaginary line, the area where the imaginary line intersects with both elements exists at least locally.

[0027] In this embodiment, such as Figure 3 As shown, the differential gear mechanism 5 also includes a pair of pinions 52 and a pair of half-shaft gears 53. Here, both the pinions 52 and the half-shaft gears 53 are bevel gears.

[0028] In this embodiment, the differential input component 51 is a hollow component that houses a pair of pinions 52 and a pair of half-shaft gears 53. The differential input component 51 is connected to the fourth gear 4D and rotates as a single unit.

[0029] A pair of pinions 52 are arranged to be spaced apart and facing each other in a radial direction R with the first axis X1 as a reference. Furthermore, the pair of pinions 52 are mounted on a pinion shaft 52a supported and rotated integrally with the differential input component 51. Each of the pair of pinions 52 is configured to be able to rotate (rotate) about the pinion shaft 52a and to rotate (revolve) about the first axis X1.

[0030] A pair of half-shaft gears 53 mesh with a pair of pinions 52. The pair of half-shaft gears 53 are configured to rotate about a first axis X1. The pair of half-shaft gears 53 are configured to be spaced apart from each other in the axial direction L and are positioned opposite each other across the pinion shaft 52a.

[0031] As previously described, housing 9 houses the rotary motor 1, input shaft 2, reduction mechanism 4, and differential gear mechanism 5. In this embodiment, housing 9 also houses a pair of output components 3.

[0032] like Figure 1 As shown, in this embodiment, the housing 9 has a first receiving section A1 and a second receiving section A2 inside. The first receiving section A1 contains space for accommodating the rotary motor 1. The second receiving section A2 contains space for accommodating the reduction mechanism 4 and the differential gear mechanism 5.

[0033] In this embodiment, the housing 9 includes a partition wall portion 91, a first peripheral wall portion 92a, a first side wall portion 92b, a second peripheral wall portion 93a, a second side wall portion 93b, and a support wall portion 94.

[0034] The partition 91 is configured to separate the first receiving portion A1 and the second receiving portion A2. In this embodiment, the partition 91 is configured to extend in the radial direction R. That is, the partition 91 separates the first receiving portion A1 and the second receiving portion A2 in the axial direction L.

[0035] The first circumferential wall portion 92a is formed to cover the rotating motor 1 from the outer side of the radial direction R. In Figure 1 In the example shown, the stator 11 of the rotary motor 1 is fixed to the first peripheral wall portion 92a. In this embodiment, the rotary motor 1 is an inner rotor type. That is, the stator 11 is disposed on the outer side of the radial direction R compared to the rotor 12. Therefore, the stator core 111 is disposed on the outer side of the radial direction R compared to the rotor core 121.

[0036] Furthermore, in this embodiment, the rotary motor 1 is a rotating magnetic field type. Therefore, a stator coil is wound around the stator core 111. The stator coil is wound around the stator core 111 in such a way that a pair of coil ends 112 protrude from the stator core 111 toward the first axial side L1 and the second axial side L2. In addition, a permanent magnet 122 is provided on the rotor core 121.

[0037] The first sidewall portion 92b is formed to cover the first axial side L1 of the rotary motor 1. In this embodiment, the first peripheral wall portion 92a is formed as a cylinder with an opening on the first axial side L1. Furthermore, the opening on the first axial side L1 of the first peripheral wall portion 92a is blocked by the first sidewall portion 92b. On the other hand, a partition wall portion 91 is integrally provided on the portion of the first peripheral wall portion 92a that is closer to the second axial side L2 than the rotary motor 1.

[0038] The second peripheral wall portion 93a is formed to cover the reduction mechanism 4 and the differential gear mechanism 5 from the outer side of the radial direction R. The second side wall portion 93b is formed to cover the reduction mechanism 4 and the differential gear mechanism 5 from the second axial side L2. In this embodiment, the second peripheral wall portion 93a is formed as a cylinder with an opening on the second axial side L2. Furthermore, the opening on the second axial side L2 of the second peripheral wall portion 93a is blocked by the second side wall portion 93b. On the other hand, a partition wall portion 91 is integrally provided on the portion of the second peripheral wall portion 93a closer to the first axial side L1 than the first gear 4A.

[0039] In this embodiment, the first receiving portion A1 is formed by a partition wall portion 91, a first peripheral wall portion 92a, and a first side wall portion 92b. That is, the space inside the housing 9 surrounded by the partition wall portion 91, the first peripheral wall portion 92a, and the first side wall portion 92b is formed as the first receiving portion A1.

[0040] Furthermore, in this embodiment, the second receiving section A2 is formed by a partition wall 91, a second peripheral wall 93a, and a second side wall 93b. That is, the space inside the housing 9 surrounded by the partition wall 91, the second peripheral wall 93a, and the second side wall 93b is formed as the second receiving section A2.

[0041] In this embodiment, the support wall portion 94 includes a portion that supports the input shaft 2 and the differential gear mechanism 5. The support wall portion 94 is disposed inside the housing 9. Figure 1 In the example shown, the support wall portion 94 is disposed inside the second receiving portion A2 and extends from the outer side to the inner side in the radial direction R. Additionally, Figure 1The support wall portion 94 shown is a separate component from the second side wall portion 93b and is fixed to the second side wall portion 93b. When viewed in the axial direction L, the support wall portion 94 overlaps with the configuration area of ​​at least one of the rotor 12 and the differential gear mechanism 5. Alternatively, the support wall portion 94 can be integrally formed with the second side wall portion 93b, provided that the housing 9 can support the input shaft 2 and the differential gear mechanism 5. Furthermore, the support wall portion 94 can also be fixed to the second peripheral wall portion 93a, or it can be integrally formed with the second peripheral wall portion 93a.

[0042] In this embodiment, the input shaft 2, on 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 housing 9. Furthermore, the reduction mechanism 4 and the differential gear mechanism 5 are housed in the second housing portion A2 and are rotatably supported by the housing 9. The support structure for the input shaft 2, the reduction mechanism 4, and the differential gear mechanism 5 will be described below.

[0043] In this embodiment, such as Figure 1 and Figure 3 As shown, the input 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. In this embodiment, the second shaft end portion 25 corresponds to the "second supported portion". 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.

[0044] The first shaft end 21 is the portion supported by the first input bearing B11, which will be described later. Figure 1 In the example shown, the first shaft end 21 is formed as a cylinder with an axis along the axial direction L.

[0045] The rotor 12 is fixed at the rotor fixing part 22. The rotor fixing part 22 is formed as a cylinder having an axis along the axial direction L. Figure 1 In the example shown, the rotor fixing part 22 is configured to protrude from the rotor 12 toward the first axial side L1 and the second axial side L2, respectively.

[0046] The bearing fitting part 23 is fitted with the third input bearing B13, which will be described later. Figure 1 In the example shown, the bearing fitting part 23 is formed as a cylinder with an axis along the axial direction L.

[0047] The first gear connecting part 24 includes a portion to which the first gear 4A is connected. Figure 1 and Figure 3 The illustrated first gear 4A is integrally formed on the outer peripheral surface of the first gear connecting portion 24. Furthermore, Figure 1 and Figure 3The illustrated first gear connecting portion 24 is a component independent of the first shaft end portion 21, the rotor fixing portion 22, and the bearing fitting portion 23, and is formed into a cylindrical shape with an axis along the axial direction L. The first gear connecting portion 24 is a structure that fits into the bearing fitting portion 23 and engages with the bearing fitting portion 23 via splines.

[0048] The second shaft end 25 is the portion supported by the second input bearing B12, which will be described later. Figure 1 and Figure 3 In the example shown, the second shaft end 25 is a portion that protrudes axially to the second side L2 relative to the first gear 4A. In detail, the second shaft end 25 is a component integral with the first gear connection portion 24, and is formed into a cylindrical shape having an axis along the axial direction L.

[0049] like Figure 1 As shown, the rotor 12 and the input shaft 2 are connected to each other with the inner circumferential surface of the rotor 12 in contact with the outer circumferential surface of the input shaft 2. In this embodiment, the inner circumferential surface of the rotor 12 is the inner circumferential surface of the rotor core 121. In this embodiment, the outer circumferential surface of the input shaft 2 is the outer circumferential surface of the rotor fixing part 22.

[0050] like Figure 1 and Figure 2 As shown, the input shaft 2 is supported at three different positions along the axial direction L by the first input bearing B11, the second input bearing B12, and the third input bearing B13, allowing it to rotate relative to the housing 9. In this embodiment, the second input bearing B12 is equivalent to "the second bearing".

[0051] The first input bearing B11 is disposed on the first axial side L1 relative to the rotor 12. The first input bearing B11 rotatably supports the input shaft 2. In this embodiment, the first input bearing B11 is configured to support the outer peripheral surface of the first shaft end 21 of the input shaft 2 from the outer side in a radial direction R. Figure 1 In the example shown, the first sidewall portion 92b of the housing 9 includes a first bearing support portion 92c. The first bearing support portion 92c is formed as a cylinder extending axially along L, overlapping the first shaft end portion 21 radially R further inward than the first shaft end portion 21 when viewed radially R. Furthermore, a first input bearing B11 is disposed between the inner circumferential surface of the first bearing support portion 92c and the outer circumferential surface of the first shaft end portion 21.

[0052] The second input bearing B12 is disposed on the second axial side L2 relative to the first gear 4A. The second input bearing B12 is configured to rotatably support the second shaft end 25 of the input shaft 2. In this embodiment, the second input bearing B12 is configured to support the outer peripheral surface of the second shaft end 25 from the outer side of the radial direction R. Furthermore, the second input bearing B12 is supported by the housing 9 via the first end 511 and the first differential bearing B31, which will be described later.

[0053] like Figure 1 As shown, the third input bearing B13 is axially positioned between the rotor 12 and the first gear 4A. The third input bearing B13 supports the input shaft 2, allowing it to rotate. In this embodiment, the third input bearing B13 is configured to support the bearing mating portion 23 from the outer side in the radial direction R. In this example, the third input bearing B13 is configured to support the outer peripheral surface of the bearing mating portion 23 from the outer side in the radial direction R. Figure 1 In the example shown, the housing 9 has a third bearing support portion 91a that supports the third input bearing B13 from the outer side of the radial direction R. Furthermore, the third input bearing B13 is supported by the third bearing support portion 91a. The third bearing support portion 91a is formed as a cylindrical shape extending axially along L such that it overlaps with the bearing engagement portion 23 of the input shaft 2 at a location radially outer of the bearing engagement portion 23 when viewed radially R.

[0054] The intermediate gear mechanism 41 is supported by the first secondary shaft bearing B21 and the second secondary shaft bearing B22, allowing it to rotate relative to the housing 9. Figure 1 and Figure 3 In the example shown, the first countershaft bearing B21 and the second countershaft bearing B22 support the countershaft 411 so that it can rotate. The first countershaft bearing B21 is positioned axially to the first side L1 above the second gear 4B. The second countershaft bearing B22 is positioned axially to the second side L2 above the third gear 4C. In this embodiment, the second countershaft bearing B22 is equivalent to the "fourth bearing".

[0055] In this embodiment, the first secondary shaft bearing B21 is configured to support the outer peripheral surface of the end of the secondary shaft 411 near the axial first side L1 from the radially outer side R. Figure 1 and Figure 3 In the example shown, the partition wall portion 91 of the housing 9 includes a first secondary shaft bearing support portion 91b. The first secondary shaft bearing support portion 91b is formed as a cylinder extending axially along L such that, when viewed radially R, it overlaps with the axially first side L1 end of the secondary shaft 411 at a location radially outside the radial direction of L. Furthermore, a first secondary shaft bearing B21 is disposed between the inner circumferential surface of the first secondary shaft bearing support portion 91b and the outer circumferential surface of the axially first side L1 end of the secondary shaft 411.

[0056] In this embodiment, the second auxiliary shaft bearing B22 is configured to support the outer peripheral surface of the auxiliary shaft 411 from the radially outer side R, near the axially second side L2. Figure 1 and Figure 3In the example shown, the housing 9 includes a second secondary shaft bearing support 93c. The second secondary shaft bearing support 93c is formed as a cylinder extending axially along L such that, when viewed radially R, it overlaps with the end of the secondary shaft 411 on the radially second side L2, located radially outside the end of the secondary shaft 411 on the radially second side L2. Furthermore, a second secondary shaft bearing B22 is disposed between the inner circumferential surface of the end of the second secondary shaft bearing support 93c on the axially second side L2 and the outer circumferential surface of the secondary shaft 411.

[0057] In this embodiment, the differential gear mechanism 5 is supported by a first differential bearing B31 and a second differential bearing B32, allowing it to rotate relative to the housing 9. In this embodiment, the first differential bearing B31 is equivalent to "first bearing". Furthermore, in this embodiment, the second differential bearing B32 is equivalent to "third bearing". Figure 3 In the example shown, the differential input component 51 is supported by a first differential bearing B31 and a second differential bearing B32, allowing it to rotatably relative to the housing 9. Specifically, the differential input component 51 is rotatably supported by the housing 9 via the first differential bearing B31 at a position axially L1 further along the first side than the center position (differential gear center position) of the differential gear mechanism 5. Furthermore, in... Figure 1 In the example shown, the center position of the differential gear is the position of the axis of the pinion 52. In addition, the differential input component 51 is supported by the second differential bearing B32 at a position axially second to L2 above the center of the differential gear, and is rotatable relative to the housing 9.

[0058] The first differential bearing B31 is configured to overlap with the second input bearing B12 when viewed radially (R). Figure 1 In the example shown, the second input bearing B12 is contained within the axial L-positioned area of ​​the first differential bearing B31. Therefore, compared to configuring the first differential bearing B31 and the second input bearing B12 such that the axial L-positioned area of ​​the first differential bearing B31 partially overlaps with the axial L-positioned area of ​​the second input bearing B12, it is possible to... Figure 1 The size of the vehicle drive unit 100 shown in the axial direction L is miniaturized.

[0059] In this embodiment, the first differential bearing B31 is configured to support a first end 511 located at the center position of the differential gear in the differential input component 51, on the axial first side L1. In this embodiment, the first end 511 corresponds to the "first supported portion". Figure 3 In the example shown, the first end 511 becomes the portion of the differential input component 51 that protrudes axially toward the first side L1. Furthermore, Figure 3 The first end 511 shown is formed as a cylindrical shape extending along the axial direction L.

[0060] In this embodiment, the first end 511 is rotatably supported from the outer side of the radial R by the first differential bearing B31. Figure 3 In the example shown, the housing 9 includes a first differential bearing support 94a. The first differential bearing support 94a is formed in the support wall portion 94. The first differential bearing support 94a is formed as a cylinder extending axially along L, overlapping the first end portion 511 radially outward when viewed radially R. Furthermore, a first differential bearing B31 is disposed between the inner circumferential surface of the first differential bearing support 94a and the outer circumferential surface of the first end portion 511. Therefore, the aforementioned second input bearing B12 is supported by the first differential bearing support 94a via the first end portion 511 and the first differential bearing B31.

[0061] In this embodiment, the second differential bearing B32 is configured to support a second end portion 512 located on the second axial side L2 of the differential gear center in the differential input component 51. In this embodiment, the second end portion 512 corresponds to the "third supported portion". Figure 1 In the example shown, the second end 512 becomes a portion of the differential input component 51 that protrudes axially to the second side L2. Furthermore, the second end 512 is formed as a cylinder having a shaft along the axial direction L. Additionally, in Figure 1 and Figure 3 In the example shown, the second sidewall portion 93b of the housing 9 includes a second differential bearing support portion 93d. The second differential bearing support portion 93d is formed as a cylinder extending axially along L, overlapping the second end portion 512 radially outward when viewed radially R. Furthermore, a second differential bearing B32 is disposed between the inner circumferential surface of the second differential bearing support portion 93d and the outer circumferential surface of the second end portion 512.

[0062] The second differential bearing B32 is configured to overlap with the second auxiliary shaft bearing B22 when viewed radially R. Furthermore, the second auxiliary shaft bearing B22 is configured to overlap with the portion of the differential input component 51 that is closer to the axial first side L1 than the second end 512 when viewed radially R. Figure 1 and Figure 3 In the example shown, the second differential bearing B32 and the second countershaft bearing B22 are configured such that a portion of the configuration area of ​​the second differential bearing B32 in the axial direction L (the portion on the first axial side L1) overlaps with a portion of the configuration area of ​​the second countershaft bearing B22 in the axial direction L (the portion on the second axial side L2).

[0063] Preferred options Figure 1 and Figure 3As illustrated, at least partially, the second countershaft bearing B22 is positioned radially inside the fourth gear 4D. Furthermore, the second countershaft bearing B22 is configured to overlap with the radially extending extension 54 of the differential input component 51 when viewed axially along the L direction. Figure 3 In the example shown, extension 54 includes a fastening member for passing the fourth gear 4D through the fastening member. Figure 3 In the example shown, the portion is bolted to the differential input member 51. With this structure, the second countershaft bearing B22 can be configured using the space created on the second axial side L2 of the differential input member 51. Therefore, miniaturization of the radial R dimension of the vehicle drive unit 100 is easily achieved. Furthermore, the extension 54 can be any portion of the differential input member 51 extending radially R, and is not limited to the portion where the fourth gear 4D is fixed to the differential input member 51. For example, the extension 54 could be the portion of the differential input member 51 supporting the pinion shaft 52a, or a wall portion formed around the pinion 52 or half-shaft gear 53.

[0064] In this embodiment, each of the pair of output components 3 is integrally connected to the half-shaft gear 53 and rotates together. Furthermore, each of the pair of output components 3 is integrally connected to the drive shaft DS, which is driven to the wheel W, and rotates together. Figure 1 In the example shown, each of the pair of output components 3 is formed as a cylindrical shape with the first axis X1 as its axis. Furthermore, with the drive shaft DS positioned radially inside the pair of output components 3, they are interconnected by spline engagement.

[0065] [Other Implementation Methods]

[0066] (1) In the above embodiment, the input shaft 2 is described as having the first shaft end 21, rotor fixing part 22, and bearing fitting part 23 as well as the first gear connecting part 24 and the second shaft end 25 as independent components. However, the first shaft end 21, rotor fixing part 22, bearing fitting part 23, first gear connecting part 24, and second shaft end 25 may also be integrally formed. Conversely, the various structures constituting the input shaft 2 may also be arbitrarily separable.

[0067] (2) In the above embodiment, the case where the first gear 4A and the first gear connecting portion 24 are integrally formed has been described. However, the first gear 4A and the first gear connecting portion 24 may also be separate components. In this case, the connection method between the first gear 4A and the first gear connecting portion 24 may include, for example, spline connection, fastening by fastening components such as bolts, and joint formed by welding.

[0068] (3) In the above embodiment, a bevel gear type differential gear mechanism 5 was described as an example. However, the differential gear mechanism 5 may also be a planetary gear type. Furthermore, the differential gear mechanism 5 may also be a planetary gear type with two pinions. In this case, the differential input component 51 becomes a component that rotates integrally with the gear ring. When the differential gear mechanism 5 is a planetary gear type, the center position of the differential gear becomes the center position in the width direction of the pinion.

[0069] (4) In the above embodiment, the case where the first axis X1 and the second axis X2 are parallel to each other was described. However, it is also possible for some axes to be in a three-dimensional intersecting position relative to other axes. For example, it is also possible for the first axis X1 and the second axis X2 to be in a three-dimensional intersecting position.

[0070] (5) In the above embodiment, it is explained that the second input bearing B12 is included within the axial L-positioning region of the first differential bearing B31. However, it is also possible that the first differential bearing B31 is included within the axial L-positioning region of the second input bearing B12 when the axial L-position of the second input bearing B12 is larger than the axial L-position of the first differential bearing B31. In this case, similar to the case where the axial L-position of the first differential bearing B31 is larger than the axial L-position of the second input bearing B12, it is also possible to... Figure 1 The vehicle drive unit 100 shown is miniaturized in the axial direction L. Alternatively, the first differential bearing B31 and the second input bearing B12 may be configured such that a portion of the configuration area of ​​the first differential bearing B31 in the axial direction L partially overlaps with a portion of the configuration area of ​​the second input bearing B12 in the axial direction L.

[0071] (6) In the above embodiment, it is described that the second differential bearing B32 and the second countershaft bearing B22 are configured such that a portion of the arrangement region of the second differential bearing B32 in the axial direction L partially overlaps with a portion of the arrangement region of the second countershaft bearing B22 in the axial direction L. However, the second differential bearing B32 may also be included within the arrangement region of the second countershaft bearing B22 in the axial direction L. Conversely, it is also possible that when the dimension of the second differential bearing B32 in the axial direction L is larger than the dimension of the second countershaft bearing B22 in the axial direction L, the second countershaft bearing B22 is included within the arrangement region of the second differential bearing B32 in the axial direction L.

[0072] (7) In the above embodiment, the second auxiliary shaft bearing B22 is described as being configured to overlap with the portion of the differential input component 51 that is closer to the first axial side L1 than the second end 512 (hereinafter referred to as the "object portion") when viewed radially R. However, it is also possible to configure the second auxiliary shaft bearing B22 at a position closer to the second axial side L2 than the object portion in order to prevent the second auxiliary shaft bearing B22 from overlapping with the object portion when viewed radially R.

[0073] (8) In the above embodiment, a structure in which the second differential bearing B32 and the second countershaft bearing B22 are arranged to overlap when viewed radially R is described. However, it is also possible that, in order to prevent the second differential bearing B32 and the second countershaft bearing B22 from overlapping when viewed radially R, the second differential bearing B32 and the second countershaft bearing B22 are arranged at different positions in the axial direction L.

[0074] (9) Furthermore, the structures disclosed in the above embodiments can also be combined with structures disclosed in other embodiments, provided that no contradiction arises. 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.

[0075] [Summary of this implementation method]

[0076] The following is a summary of the embodiments of the vehicle drive device (100) described above.

[0077] A vehicle drive unit (100) includes: a rotary motor (1) having a rotor (12); an input shaft (2) integrally rotated with the rotor (12); a pair of output components (3) respectively driven connected to wheels (W); a reduction mechanism (4) that reduces the rotation of the input shaft (2); a differential gear mechanism (5) having a differential input component (51) and distributing the rotation transmitted from the reduction mechanism (4) to the differential input component (51) to the pair of output components (3); and a housing (9) that houses the rotary motor (1), the input shaft (2), the reduction mechanism (4), and the differential gear mechanism (5), wherein the rotor (12), the input shaft (2), the pair of output components (3), and the differential gear mechanism (5) are arranged on a first shaft (X1), and the reduction mechanism (4) includes: a first gear (4A) arranged on the first shaft (X1) and connected to the input shaft (12). The shaft (2) is connected to rotate as a whole; the intermediate gear mechanism (41) has a second gear (4B) meshing with the first gear (4A) and a third gear (4C) connected to the second gear (4B) and rotating as a whole, and is arranged on a second shaft (X2) that is on a different axis from the first shaft (X1); and a fourth gear (4D) is arranged on the first shaft (X1) and meshes with the third gear (4C) and is connected to the differential input component (51). The differential input component (51) is rotatable relative to the housing (9) by being supported by the first bearing (B31), and the input shaft (2) is rotatable relative to the differential input component (51) by being supported by the second bearing (B12) with the direction orthogonal to the first axis (X1) as the radial direction (R). When viewed along the radial direction (R), the first bearing (B31) and the second bearing (B12) are configured to overlap.

[0078] According to this structure, the differential input component (51) employing the differential gear mechanism (5) is supported by the housing (9) via the first bearing (B31), and the input shaft (2) is supported by the differential input component (51) via the second bearing (B12). This structure allows the first bearing (B31) and the second bearing (B12) to be arranged overlapping when viewed radially (R) without complicating the shape of the housing (9). Furthermore, by arranging the first bearing (B31) and the second bearing (B12) overlapping when viewed radially (R), compared to arranging these components in a non-overlapping positional relationship when viewed radially (R), it is easier to achieve miniaturization of the axial (L) dimension of the vehicle drive unit (100).

[0079] In the vehicle drive unit (100), the direction along the first axis (X1) is taken as the axial direction (L), one side of the axial direction (L) is taken as the first axial side (L1), the other side of the axial direction (L) is taken as the second axial side (L2), and the center position of the differential gear mechanism (5) on the axial direction (L) is taken as the center position of the differential gear. The rotor (12), the first gear (4A), and the differential gear mechanism (5) are located on the first axis (X1) from the... The first axial side (L1) is arranged in the order described to the second axial side (L2). The first bearing (B31) is configured to support a first supported portion (511) of the differential input component (51) located on the first axial side (L1) at a position closer to the center of the differential gear than the center of the differential gear. The second bearing (B12) is configured to support a second supported portion (25) of the input shaft (2) located on the second axial side (L2) closer to the first gear (4A) than the center of the differential gear.

[0080] According to this structure, the input shaft (2) and the differential input component (51) can be properly supported respectively, and the first bearing (B31) and the second bearing (B12) for supporting them can be properly configured using the space surrounded by the first gear (4A), the second gear (4B) and the differential gear mechanism (5).

[0081] In the vehicle drive unit (100), the differential input component (51) is rotatable relative to the housing (9) by a third bearing (B32) at a position on the second axial side (L2) of the differential gear, and the intermediate gear mechanism is rotatable relative to the housing (9) by a fourth bearing (B22) at a position on the second axial side (L2) of the third gear (4C), and the third bearing (B32) and the fourth bearing (B22) are configured to overlap when viewed radially (R).

[0082] According to this structure, the third bearing (B32) and the fourth bearing (B22) are arranged to overlap when viewed radially (R). Thus, compared with this structure in which these components are arranged in a positional relationship that does not overlap when viewed radially (R), it is easier to achieve miniaturization of the axial (L) dimension of the vehicle drive unit (100).

[0083] In the vehicle drive unit (100), the third bearing (B32) is configured to support the third supported portion (512) of the differential input component (51) located on the second axial side (L2) of the differential gear, and the fourth bearing (B22) is configured to overlap with the portion of the differential input component (51) located on the first axial side (L1) of the differential input component (51) when viewed radially (R).

[0084] According to this structure, the fourth bearing (B22) is configured to overlap with both the third bearing (B32) and the portion of the differential input component (51) that is axially closer to the first side (L1) than the third supported portion (512) when viewed radially (R). Therefore, the fourth bearing (B22) can be configured using the space created on the radially (R) outer side of the differential gear mechanism (5). As a result, miniaturization of the vehicle drive unit (100) can be easily achieved.

[0085] Industrial applicability

[0086] The technology disclosed herein can be used in vehicle drive systems that include a rotary motor having a rotor and a speed reduction mechanism for slowing down the rotation of the rotor.

[0087] Explanation of reference numerals in the attached figures

[0088] 100...Vehicle drive unit; 1...Rotary motor; 12...Rotor; 2...Input shaft; 25...Second shaft end (second supported part); 3...Output component; 4...Reduction mechanism; 4A...First gear; 41...Intermediate gear mechanism; 4B...Second gear; 4C...Third gear; 4D...Fourth gear; 5...Differential gear mechanism; 51...Differential input component; 511...First end (first supported part); 512...Second end (third supported part); 9...Housing; B12...Second input bearing (second bearing); B22...Second auxiliary shaft bearing (fourth bearing); B31...First differential bearing (first bearing); B32...Second differential bearing (third bearing); L...Axial; L1...First side of axial direction; L2...Second side of axial direction; R...Radial; WH...Wheel; X1...First axle center; X2...Second axle center.

Claims

1. A drive device for a vehicle, comprising: an electric rotating machine including a rotor; an input shaft connected to the rotor so as to rotate integrally with the rotor; a pair of output members each connected to a wheel so as to drive the wheel; a reduction mechanism that reduces rotation of the input shaft; a differential gear mechanism including a differential input member and distributing rotation transmitted from the reduction mechanism to the differential input member to the pair of output members; and a housing that houses the electric rotating machine, the input shaft, the reduction mechanism, and the differential gear mechanism, wherein the drive device for a vehicle is characterized in that: the rotor, the input shaft, the pair of output members, and the differential gear mechanism are arranged on a first axis line; the reduction mechanism includes: a first gear arranged on the first axis line and connected to the input shaft so as to rotate integrally with the input shaft; an intermediate gear mechanism including a second gear engaged with the first gear and a third gear connected to the second gear so as to rotate integrally with the second gear, and arranged on a second axis line different from the first axis line; and a fourth gear arranged on the first axis line, engaged with the third gear, and connected to the differential input member so as to rotate integrally with the differential input member; the differential input member is rotatably supported with respect to the housing via a first bearing; the input shaft is rotatably supported with respect to the differential input member via a second bearing; a direction orthogonal to the first axis line is a radial direction; and the first bearing and the second bearing are arranged so as to overlap each other when viewed in the radial direction.

2. The drive device for a vehicle according to claim 1, wherein: a direction along the first axis line is an axial direction, one side of the axial direction is an axial first side, the other side of the axial direction is an axial second side, and a center position of the differential gear mechanism in the axial direction is a differential gear center position; the rotor, the first gear, and the differential gear mechanism are arranged on the first axis line in the order from the axial first side to the axial second side; the first bearing supports a first supported portion provided at the differential input member on the axial first side of the differential gear center position; and the second bearing supports a second supported portion provided at the input shaft on the axial second side of the first gear.

3. The drive device for a vehicle according to claim 2, wherein: the differential input member is rotatably supported with respect to the housing via a third bearing at a position on the axial second side of the differential gear center position; the intermediate gear mechanism is rotatably supported with respect to the housing via a fourth bearing at a position on the axial second side of the third gear; and the third bearing and the fourth bearing are arranged so as to overlap each other when viewed in the radial direction.

4. The drive device for a vehicle according to claim 3, wherein: the third bearing supports a third supported portion provided at the differential input member on the axial second side of the differential gear center position. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The fourth bearing is configured to overlap, in radial view, the portion of the differential input component that is closer to the axial first side than the third supported portion.

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