Vehicle drive device

Abstract

To reduce primary vibration of rotation of a rotor while suppressing increase of torque loss in a power transmission route, in a single-shaft vehicle drive device comprising a two-stage planetary gear mechanism comprising one sun gear as a reducer, two planetary gears supported by a common carrier, and two ring gears.SOLUTION: A rotation electric machine 1, a planetary gear mechanism 4, and an output differential gear device 5 are arranged coaxially. A differential case 51 is supported in a radial direction R relative to a case 9 in a state where the same can rotate freely relative to the case 9 via a bush B5 that is arranged on the opposite side of a differential gear mechanism 50 from the side where the planetary gear mechanism 4 is located, and in a position overlapping with the differential gear mechanism 50 when viewed in an axial direction L. A carrier CR is supported in the radial direction R relative to the case 9 in a state where the same can rotate freely relative to the case 9 via a rolling bearing B4.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a vehicle drive device.

Background Art

[0002] International Publication No. 2023 / 068334 discloses a so-called single-axis type vehicle drive device (100) in which a rotary electric machine (1) serving as a driving force source for a pair of wheels (W1, W2), a planetary gear mechanism (4) functioning as a speed reducer, and a differential gear device (5) for distributing power to the pair of wheels (W1, W2) are arranged coaxially. (In the background art, the reference numerals in parentheses refer to those in the cited document.) The planetary gear mechanism (4) is a two-stage planetary gear mechanism sharing a carrier (CR1), and includes one sun gear (SG1), a first planetary gear (PG1) meshing with the sun gear (SG1), a first ring gear (RG1) meshing with the first planetary gear (PG1), a second planetary gear (PG2) supported by the carrier (CR1) together with the first planetary gear (PG1) and rotating integrally with the first planetary gear (PG1), and a second ring gear (RG2) meshing with the second planetary gear (PG2). When the first ring gear (RG1) is fixed and the carrier (CR1) is free, and the input from the sun gear (SG1) of the planetary gear mechanism is output from the second ring gear (RG2), a high reduction ratio of at least about 20 can be achieved while suppressing the radial dimension to be small. This vehicle drive device (1) is easy to achieve a large reduction ratio, easy to amplify torque, and easy to miniaturize the rotary electric machine (1).

[0003] Further, when using a speed reducer with the above-described planetary gear mechanism (4) in a single-axis type vehicle drive device (100), it is easy to perform a design that cancels the meshing reaction force of the gears in the radial direction, and by omitting the radial bearings, the torque loss in the power transmission path can be reduced. In addition to being easy to miniaturize the rotary electric machine (1), by not providing the radial bearings, it is easy to configure the vehicle drive device (100) to be smaller.

Prior Art Documents

Patent Documents

[0004] Patent Document 1 International Publication No. 2023 / 068334 Summary of the Invention Problems to be Solved by the Invention

[0005] As described above, when the vehicle drive device is miniaturized by reducing the radial bearings, the centrifugal force due to the eccentricity of the rotor of the rotating electric machine tends to increase when the rotating electric machine rotates at high speed. As a result, the planetary gear may be oscillated, and the primary vibration of the rotor rotation may be prominent in the vehicle drive device as a whole. In order to suppress such vibration, either or both of (i) a carrier that supports the planetary gear and (ii) an input rotating element of a differential gear device that rotates integrally with a second ring gear that is an output rotating element of the planetary gear mechanism are supported radially with respect to the case via bearings or the like. can be considered. However, if radial bearings or the like are added easily, the torque loss in the power transmission path increases. In addition, providing such a radial support mechanism may increase the radial dimensions of the vehicle drive device.

[0006] In view of the above background, in a single-shaft type vehicle drive device including a planetary gear mechanism having a two-stage configuration including two planetary gears and two ring gears supported by a common carrier with one sun gear as a speed reducer, it is possible to suppress an increase in torque loss in the power transmission path while reducing the primary vibration of the rotor rotation. It is desired to make it smaller. Means for Solving the Problems

[0007] The vehicle drive device in view of the above includes a rotary electric machine having a rotor, a first output member drivingly connected to a first wheel, a second output member drivingly connected to a second wheel, a planetary gear mechanism that decelerates the rotation of the rotor, a differential case, and a differential gear mechanism housed in the differential case, and an output differential gear device that distributes the rotation transmitted from the planetary gear mechanism to the differential case to the first output member and the second output member, and a case that houses the rotary electric machine, the planetary gear mechanism, and the output differential gear device. The rotary electric machine, the first output member, the second output member, the planetary gear mechanism, and the output differential gear device are arranged coaxially. The planetary gear mechanism includes a sun gear, a carrier, a first ring gear, and a second ring gear. The sun gear is connected so as to rotate integrally with the rotor. The first ring gear is connected to a non-rotating member. The second ring gear is connected so as to rotate integrally with the differential case. The carrier rotatably supports a first pinion gear and a second pinion gear that rotate integrally with each other. The first pinion gear meshes with the sun gear and the first ring gear. The second pinion gear has a smaller diameter than the first pinion gear and meshes with the second ring gear. With the direction along the rotation axis of the rotor as the axial direction and the direction orthogonal to the rotation axis as the radial direction, the differential case is supported by the case in a rotatable state with respect to the case in the radial direction via a bush disposed on the side opposite to the side where the planetary gear mechanism is located with respect to the differential gear mechanism and overlapping the differential gear mechanism in the axial view. The carrier is supported by the case in a rotatable state with respect to the case in the radial direction via a rolling bearing.

[0008] According to this configuration, a carrier that supports the first pinion gear and the second pinion gear is stably supported in the radial direction with respect to the case via a rolling bearing. Thereby, even if vibration caused by the eccentricity of the rotor is transmitted through the first pinion gear, vibration of the carrier is suppressed. The output differential gear device is supported by automatic centering due to the meshing of the second ring gear on the side of the planetary gear mechanism, and is supported on the side opposite to the planetary gear mechanism with a slight radial clearance with respect to the case via a bush. Even if the output differential gear device is not strongly supported in the radial direction, since vibration of the carrier is suppressed, transmission of vibration caused by the eccentricity to the output differential gear device through the second pinion gear is suppressed. Since the additional support structure in the radial direction is substantially limited to the rolling bearing that supports the carrier, an increase in torque loss in the power transmission path from the rotating electrical machine to the output member is also suppressed. Thus, according to this configuration, in a single-shaft type vehicle drive device including a planetary gear mechanism having a two-stage configuration including one sun gear, two planetary gears supported by a common carrier, and two ring gears as a speed reducer, an increase in torque loss in the power transmission path can be suppressed while reducing the primary vibration of the rotation of the rotor.

[0009] Further features and advantages of the vehicle drive device will become apparent from the following description of exemplary and non-limiting embodiments with reference to the drawings.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0011] Hereinafter, with reference to the drawings, two embodiments of a vehicle drive device will be exemplified and described in two aspects, a first example and a second example. In the first example and the second example, the configuration of the power transmission mechanism is common, and the skeleton diagram of FIG. 1 is common to the first example and the second example. FIG. 2 shows a schematic cross-sectional view of the vehicle drive device 100 of the first example, and FIG. 3 shows a schematic cross-sectional view of the vehicle drive device 100 of the second example. Matters common to the first example and the second example will be described without distinguishing between the first example and the second example.

[0012] As shown in FIGS. 1 to 3, the vehicle drive device 100 includes a rotary electric machine 1 that serves as a driving force source for a pair of wheels, a first output member 2 drivingly connected to the first wheel W1, a second output member 3 drivingly connected to the second wheel W2, a planetary gear mechanism 4, an output differential gear device 5, and a case 9. At least one of a first differential side gear 54 and a first drive shaft DS1, which will be described later, corresponds to the first output member 2, and at least one of a second differential side gear 56, a second drive shaft DS2, and a connecting shaft 30, which will be described later, corresponds to the second output member 3. The case 9 houses the rotary electric machine 1, the planetary gear mechanism 4, and the output differential gear device 5. The first differential side gear 54, the second differential side gear 56, and the connecting shaft 30 are also housed in the case 9, and when these correspond to the first output member 2 and the second output member 3, respectively, the case 9 also houses the first output member 2 and the second output member 3. When the first drive shaft DS1 and the second drive shaft DS2 correspond to the first output member 2 and the second output member 3, respectively, the case 9 houses a part of the first drive shaft DS1 and the second drive shaft DS2.

[0013] Here, in this specification, "driving connection" refers to a state in which two rotating elements are connected so as to be able to transmit a driving force, including a state in which the two rotating elements are connected so as to rotate integrally, or a state in which the two rotating elements are connected so as to be able to transmit a driving force via one or more transmission members. Such transmission members include various members that transmit rotation at the same speed or with speed change, for example, shafts, gear mechanisms, belts, chains, etc. Note that as the transmission member, an engagement device that selectively transmits rotation and a driving force, for example, a friction engagement device, a meshing engagement device, etc. may be included.

[0014] In the following description, the direction along the rotation axis center of the rotating electrical machine 1 (the rotation axis center of the rotor 12 (rotor axis A)) is defined as the "axial direction L". And one side of the axial direction L is defined as the "first axial side L1", and the other side of the axial direction L is defined as the "second axial side L2". Also, the direction orthogonal to the rotor axis A is defined as the "radial direction R". And in the radial direction R, the side of the rotor axis A is defined as the "radial inner side R1", and the opposite side is defined as the "radial outer side R2". Also, the direction of orbiting around the rotor axis A is defined as the "circumferential direction".

[0015] The rotating electrical machine 1, the first output member 2, the second output member 3, the planetary gear mechanism 4, and the output differential gear device 5 are arranged coaxially. In the present embodiment, they are arranged in the order of the rotating electrical machine 1, the planetary gear mechanism 4, and the output differential gear device 5 from the second axial side L2 toward the first axial side L1. Regarding the arrangement of two elements, "overlapping in a specific direction view" means that when a virtual straight line parallel to the line-of-sight direction is moved in each direction orthogonal to the virtual straight line, there is at least a part of a region where the virtual straight line intersects both of the two elements.

[0016] As shown in FIGS. 2 and 3, in the present embodiment, the case 9 includes a peripheral wall portion 91, a first side wall portion 92, a second side wall portion 93, and a support wall portion 94.

[0017] The peripheral wall portion 91 is formed in a cylindrical shape that covers the radially outer side R2 of the rotating electrical machine 1, the first output member 2, the second output member 3, the planetary gear mechanism 4, and the output differential gear device 5. Each of the first side wall portion 92, the second side wall portion 93, and the support wall portion 94 is formed to extend in the radial direction R and the circumferential direction. In the present embodiment, the first side wall portion 92 is formed to cover the first axial side L1 of the output differential gear device 5. And the second side wall portion 93 is formed to cover the second axial side L2 of the rotating electrical machine 1. Further, the support wall portion 94 is disposed between the rotating electrical machine 1 and the planetary gear mechanism 4 in the axial direction L so as to partition the accommodation space of the rotating electrical machine 1 and the accommodation spaces of the planetary gear mechanism 4 and the output differential gear device 5.

[0018] As shown in FIGS. 2 and 3, the peripheral wall portion 91 is formed by two case members that abut in the axial direction L. And in the first example of the vehicle drive device 100 shown in FIG. 2, the first side wall portion 92 is integrally formed with the peripheral wall portion 91 so as to close the opening on the first axial side L1 of the peripheral wall portion 91. In the second example of the vehicle drive device 100 shown in FIG. 3, the first side wall portion 92 is formed by a member different from the member forming the peripheral wall portion 91, and abuts on the member forming the peripheral wall portion 91 from the first axial side L1 so as to close the opening on the first axial side L1 of the peripheral wall portion 91. Also, as shown in FIGS. 2 and 3, the second side wall portion 93 is formed by a member different from the member forming the peripheral wall portion 91, and abuts on the member forming the peripheral wall portion 91 from the second axial side L2 so as to close the opening on the second axial side L2 of the peripheral wall portion 91.

[0019] The rotating electrical machine 1 is a driving force source for the first wheel W1 and the second wheel W2. The rotating electrical machine 1 has a function as a motor (electric motor) that receives power supply and generates power, and a function as a generator (electric generator) that receives power supply and generates electric power. Specifically, the rotating electrical machine 1 is electrically connected to a power storage device (not shown) such as a battery or a capacitor. The rotating electrical machine 1 generates a driving force by the electric power stored in the power storage device (power running). Also, the rotating electrical machine 1 generates electricity by the driving force transmitted from the sides of the first wheel W1 and the second wheel W2 to charge the power storage device (regeneration).

[0020] The rotating electrical machine 1 is an inner rotor type rotating electrical machine having a rotor 12 on the radially inner side R1 of a stator 11. Further, the rotating electrical machine 1 is a rotating field type rotating electrical machine, the stator 11 includes a stator coil, and the rotor 12 includes a permanent magnet. The rotor 12 is connected to a hollow rotor shaft 13 through which a connecting shaft 30 passes on the radially inner side R1, and the rotor 12 and the rotor shaft 13 rotate integrally. On the outer peripheral side of the rotor shaft 13, a sun gear SG which is an input rotating element of a planetary gear mechanism 4 constituting a speed reducer is arranged to rotate integrally with the rotor shaft 13. The sun gear SG may be integrally formed by the same member as the rotor shaft 13, or may be formed by a separate member from the rotor shaft 13 and connected to the rotor shaft 13 by welding or the like. The rotor shaft 13 is rotatably supported with respect to a support wall portion 94 via a first rotor bearing B1 on the first axial side L1, and is rotatably supported with respect to a second side wall portion 93 via a second rotor bearing B2 on the second axial side L2.

[0021] The planetary gear mechanism 4 that functions as a speed reducer includes an input rotating element (sun gear SG) that rotates integrally with the rotor shaft 13, a fixed element (first ring gear RG1) fixed to the case 9 that is a non-rotating member, an output rotating element (second ring gear RG2) that rotates integrally with a differential input element (differential case 51), and planetary gears (first pinion gear PG1, second pinion gear PG2). In the present embodiment, the planetary gear mechanism 4 is a composite planetary gear mechanism including one sun gear SG, two ring gears (first ring gear RG1, second ring gear RG2), and two planetary gears (first pinion gear PG1, second pinion gear PG2) that are rotatably supported by a common carrier CR and rotate integrally. The two planetary gears rotate about the rotor axis A, which is the axis of rotation of the planetary gear mechanism 4, while rotating about the pinion shaft fixed to the carrier CR as the axis of rotation and revolving around the carrier CR. In the present embodiment, the second pinion gear PG2 is formed with a smaller diameter than the first pinion gear PG1. The first pinion gear PG1 meshes with the sun gear SG and the first ring gear RG1, and the second pinion gear PG2 rotates integrally with the first pinion gear PG1 and meshes with the second ring gear RG2. The carrier CR is not connected to any of the rotating elements and the fixed elements.

[0022] In this embodiment, the first ring gear RG1 is fixed to a support wall portion 94 disposed between the rotating electrical machine 1 and the planetary gear mechanism 4 in the axial direction L in the case 9. That is, the non-rotating member that fixes the first ring gear RG1 is the support wall portion 94 and the case 9. As shown in FIGS. 2 and 3, the support wall portion 94 includes a protruding portion 41 that protrudes from the support wall portion 94 toward the first side L1 in the axial direction. The protruding portion 41 is, for example, an annular member. The protruding portion 41 overlaps the first ring gear RG1 and the first pinion gear PG1 in a radial view. The protruding portion 41 may be integrally formed with the support wall portion 94, or may be formed of a member different from the support wall portion 94 and connected to the support wall portion 94 by welding or the like. In this embodiment, the protruding portion 41 is connected to the support wall portion 94 via a support member 42 extending in the radial direction R. The first ring gear RG1 is formed, for example, as a tooth portion (such as a spline engagement portion) on the inner side R1 in the radial direction of the protruding portion 41. Therefore, at least one of the protruding portion 41 and the support member 42 can be referred to as a connecting portion between the first ring gear RG1 and the support wall portion 94.

[0023] Naturally, the first ring gear RG1 may be fixed not to the support wall portion 94 but to the inner wall surface 9a of the peripheral wall portion 91 or a radially protruding portion that protrudes from the inner wall surface 9a of the peripheral wall portion 91 in the radial direction R. This radially protruding portion may also be integrally formed with the peripheral wall portion 91, or may be formed of a member different from the peripheral wall portion 91 and connected to the support wall portion 94 by welding or the like.

[0024] The carrier CR is supported in the radial direction R with respect to the case 9 in a rotatable state with respect to the case 9 via the carrier bearing B4. The carrier bearing B4 is a rolling bearing. Common to the first example and the second example, the carrier bearing B4 supports the carrier CR from the radially outer side R2. As shown in FIG. 2, in the vehicle drive device 100 of the first example, the carrier CR is supported from the radially outer side R2 at a position radially inward R1 of the pinion shaft supported by the carrier CR. Therefore, by arranging the carrier bearing B4, an increase in the radial dimension of the planetary gear mechanism 4 is suppressed. Further, in the vehicle drive device 100 of the second example, as shown in FIG. 3, the carrier bearing B4 is arranged on the radially outer side R2 of the carrier CR. However, as will be described later, by arranging the carrier bearing B4 in a space where the distance in the radial direction R is likely to increase between the inner wall surface 9a of the case 9 and the planetary gear mechanism 4, an increase in the radial dimension is suppressed.

[0025] In the vehicle drive device 100 of the first example shown in FIG. 2, the carrier bearing B4 is supported by the support wall portion 94. As described above, the protruding portion 41 protrudes from the support wall portion 94 toward the first side L1 in the axial direction. Further, the protruding portion 41 is supported by the support wall portion 94 via the support member 42 from the radially inner side R1. The carrier bearing B4 is arranged at a position overlapping the protruding portion 41 and the support member 42 in a radial view along the radial direction R. As described above, at least one of the protruding portion 41 and the support member 42 is a connecting portion between the first ring gear RG1 and the support wall portion 94. Therefore, it can be said that the carrier bearing B4 is arranged at a position overlapping the connecting portion between the first ring gear RG1 and the support wall portion 94.

[0026] As described above, the second pinion gear PG2 is formed to have a smaller diameter than the first pinion gear PG1. Therefore, in the radial direction R, it is easier to secure a space between the second pinion gear PG2 and the inner wall surface 9a of the peripheral wall portion 91 of the case 9 than between the first pinion gear PG1 and the inner wall surface 9a. For this reason, in the vehicle drive device 100 of the second example shown in FIG. 3, the carrier CR is configured to include an outer edge portion 43 that is located further radially outward R2 with respect to the second ring gear RG2 that meshes with the second pinion gear PG2. The outer edge portion 43 overlaps the second ring gear RG2 and the second pinion gear PG2 in a radial view. And the carrier CR is supported in a rotatable state with respect to the inner wall surface 9a of the case 9 at this outer edge portion 43. The carrier bearing B4 is disposed between the inner wall surface 9a of the case 9 and the outer edge portion 43 of the carrier CR in the radial direction R and at a position that overlaps the second ring gear RG2 in a radial view.

[0027] Incidentally, in common to the first example and the second example, a form in which the carrier CR is directly supported by the case 9 (including the support wall portion 94) via the carrier bearing B4 is illustrated. However, it does not prevent a form in which the carrier bearing B4 is supported by another member such as a bracket fixed to the case 9 and is indirectly supported by the case 9.

[0028] The output differential gear device 5 is configured by housing in the differential case 51 a bevel gear type differential gear mechanism 50 including a plurality of differential pinion gears 53, a pair of differential side gears (first differential side gear 54, second differential side gear 56), and a plurality of differential pinion shafts 52. The differential case 51 is a differential input element that is connected to the second ring gear RG2, which is an output rotation element of the planetary gear mechanism 4, and rotates integrally. For example, the second ring gear RG2 and the differential case 51 are integrally connected by welding.

[0029] The differential pinion gear 53 is supported by the differential case 51 and is rotatably supported by a plurality of differential pinion shafts 52 arranged radially (e.g., in a cross shape) about the rotation axis of the differential case 51 (rotor axis A). The first differential side gear 54 and the second differential side gear 56 mesh with respective ones of the plurality of differential pinion gears 53 and rotate about the rotation axis of the differential case 51 (rotor axis A). The first differential side gear 54 is drivingly connected to the first wheel W1 via the first drive shaft DS1. The second differential side gear 56 is drivingly connected to the second wheel W2 via the second drive shaft DS2. Incidentally, since the planetary gear mechanism 4 and the rotating electric machine 1 are arranged between the second differential side gear 56 and the second wheel W2 in the axial direction L, the second differential side gear 56 is connected to a connecting shaft 30 that penetrates the planetary gear mechanism 4 and the rotating electric machine 1 in the axial direction L, the connecting shaft 30 is connected to the second drive shaft DS2, and the second drive shaft DS2 is connected to the second wheel W2. In common to the first example and the second example, the connecting shaft 30 is rotatably supported with respect to the second side wall portion 93 via the output bearing B3.

[0030] In the planetary gear mechanism 4 of the present embodiment, when the first ring gear RG1 is fixed and the carrier CR is free, and the input from the sun gear SG of the planetary gear mechanism 4 is output from the second ring gear RG2, a high reduction ratio of 20 or more can be achieved while suppressing the dimension in the radial direction R to be small. Further, in the one-axis type vehicle drive device 100 as in the present embodiment, it is easy to perform a design that cancels out the meshing reaction force of the gears in the radial direction R of the planetary gear mechanism 4, and it is easy to reduce the torque loss in the power transmission path by omitting the bearing in the radial direction R. In addition to being easy to miniaturize the rotating electric machine 1, and being easy to reduce the bearings in the radial direction R, it is easy to configure the vehicle drive device 100 to be smaller.

[0031] However, when the number of bearings in the radial direction R decreases, when the rotor 12 of the rotating electrical machine 1 rotates at high speed, the centrifugal force due to the eccentricity of the rotor 12 tends to increase, and the primary vibration of the rotation of the rotor 12 may become prominent in the entire vehicle drive device 100 due to the oscillation of the planetary gear accompanying the centrifugal force. The vehicle drive device 100 of the present embodiment is configured to be able to reduce the primary vibration of the rotation of the rotor 12 while suppressing an increase in torque loss in the power transmission path.

[0032] As shown in FIGS. 2 and 3, in common to the first example and the second example, the differential case 51 is on the first axial side L1 opposite to the side where the planetary gear mechanism 4 is located with respect to the differential gear mechanism 50, and is disposed at a position overlapping the differential gear mechanism 50 in the axial view. It is supported in the radial direction R with respect to the case 9 in a rotatable state with respect to the case 9 via the bush B5. That is, the differential case 51 is gently supported by the case 9 with a slight radial R gap with respect to the case 9 via the bush B5. Further, the carrier CR is supported in the radial direction R with respect to the case 9 in a rotatable state with respect to the case 9 via the carrier bearing B4.

[0033] Since the carrier CR is stably supported in the radial direction R with respect to the case 9 via the carrier bearing B4 which is a rolling bearing, even if the vibration caused by the eccentricity of the rotor 12 is transmitted to the planetary gear mechanism 4 via the first pinion gear PG1, the carrier CR is suppressed from vibrating. The output differential gear device 5 is supported by self-aligning due to the engagement of the second ring gear RG2 on the side of the planetary gear mechanism 4, and is supported by the case 9 via the bush B5 on the side opposite to the planetary gear mechanism 4. Even if the output differential gear device 5 is not strongly supported in the radial direction R, since the vibration of the carrier CR of the planetary gear mechanism 4 is suppressed, the vibration caused by the eccentricity of the rotor 12 is suppressed from being transmitted to the output differential gear device 5. In the power transmission path from the rotating electrical machine 1 to the output member, since the additional rotational support structure from the radial direction R is substantially limited to the carrier bearing B4, an increase in torque loss in the power transmission path is also suppressed.

[0034] Hereinafter, the vehicle drive device (100) described above will be briefly summarized.

[0035] In one aspect, a vehicle drive device (100) includes a rotary electric machine (1) having a rotor (12), a first output member (2) drivingly connected to a first wheel (W1), a second output member (3) drivingly connected to a second wheel (W2), a planetary gear mechanism (4) that decelerates the rotation of the rotor (12), and an output differential gear device (5) including a differential case (51) and a differential gear mechanism (50) housed in the differential case (51) that distributes the rotation transmitted from the planetary gear mechanism (4) to the differential case (51) to the first output member (2) and the second output member (3), and a case (9) that houses the rotary electric machine (1), the planetary gear mechanism (4), and the output differential gear device (5). The rotary electric machine (1), the first output member (2), the second output member (3), the planetary gear mechanism (4), and the output differential gear device (5) are coaxially arranged. The planetary gear mechanism (4) includes a sun gear (SG), a carrier (CR), a first ring gear (RG1), and a second ring gear (RG2). The sun gear (SG) is connected to rotate integrally with the rotor (12). The first ring gear (RG1) is connected to a non-rotating member. The second ring gear (RG2) is connected to rotate integrally with the differential case (51). The carrier (CR) rotatably supports a first pinion gear (PG1) and a second pinion gear (PG2) that rotate integrally with each other. The first pinion gear (PG1) meshes with the sun gear (SG) and the first ring gear (RG1). The second pinion gear (PG2) has a smaller diameter than the first pinion gear (PG1) and meshes with the second ring gear (RG2). With the direction along the rotation axis (A) of the rotor (12) being the axial direction (L) and the direction orthogonal to the rotation axis (A) being the radial direction (R), the differential case (51) is supported by the case (9) in a rotatable state with respect to the case (9) in the radial direction (R) via a bush (B5) disposed on the side opposite to the side where the planetary gear mechanism (4) is located with respect to the differential gear mechanism (50) and overlapping the differential gear mechanism (50) in the axial view. The carrier (CR)It is supported in the radial direction (R) with respect to the case (9) in a rotatable state with respect to the case (9) via a rolling bearing (B4).

[0036] According to this configuration, the carrier that supports the first pinion gear (PG1) and the second pinion gear (PG2) is stably supported in the radial direction (R) with respect to the case (9) via the rolling bearing (B4). Thus, even if vibrations caused by the eccentricity of the rotor (12) are transmitted via the first pinion gear (PG1), the vibration of the carrier (CR) is suppressed. The output differential gear device (5) is supported on the side of the planetary gear mechanism (4) by self-aligning due to the meshing of the second ring gear (RG2), and on the side opposite to the planetary gear mechanism (4), it is supported with a slight radial (R) clearance with respect to the case (9) via a bush (B5). Even though the output differential gear device (5) is not strongly supported in the radial direction (R), since the vibration of the carrier (CR) is suppressed, the transmission of vibrations caused by the eccentricity to the output differential gear device (5) via the second pinion gear (PG2) is suppressed. Since the additional support structure in the radial direction (R) is substantially limited to the rolling bearing (B4) that supports the carrier (CR), an increase in torque loss in the power transmission path from the rotating electrical machine (1) to the output members (2, 3) is also suppressed. Thus, according to this configuration, in a single-shaft type vehicle drive device (100) provided with a two-stage planetary gear mechanism (4) including one sun gear (SG), two planetary gears (PG1, PG2) supported by a common carrier (CR), and two ring gears (RG1, RG2) as a speed reducer, it is possible to reduce the primary vibration of the rotation of the rotor (12) while suppressing an increase in torque loss in the power transmission path.

[0037] Further, in the vehicle drive device (100), the case (9) includes a support wall portion (94) disposed between the axial direction (L) of the rotary electric machine (1) and the planetary gear mechanism (4), the non-rotating member is the support wall portion (94), the rolling bearing (B4) is supported by the support wall portion (94), and it is preferably disposed at a position overlapping the connecting portions (41, 42) of the first ring gear (RG1) and the support wall portion (94) in a radial view along the radial direction (R).

[0038] According to this configuration, it is easy to arrange the vibration transmission path via the rolling bearing (B4) radially inward (R1). Therefore, an increase in the dimensions of the vehicle drive device (100) in the axial direction (L) and the radial direction (R) due to the arrangement of the rolling bearing (B4) can be suppressed to a small extent. Also, it is easy to reduce the diameter of the rolling bearing (B4), and it is easy to reduce the loss of rotational energy such as torque loss due to the bearing.

[0039] Further, in the vehicle drive device (100), the second ring gear (RG2) has a smaller diameter than the first ring gear (RG1), the carrier (CR) includes an outer edge portion (43) located radially outward (R2) of the second ring gear (RG2) in the radial direction (R), and the rolling bearing (B4) is between the inner wall surface (9a) of the case (9) and the outer edge portion (43) in the radial direction (R), and it is preferably disposed at a position overlapping the second ring gear (RG2) in a radial view along the radial direction (R).

[0040] According to this configuration, since the second ring gear (RG2) has a smaller diameter than the first ring gear (RG1), even if the rolling bearing (B4) is disposed radially outward of the second ring gear (RG2), an increase in the radial dimension (R) of the vehicle drive device (100) can be easily suppressed. Also, since the rolling bearing (B4) is disposed at a position overlapping the second ring gear (RG2) in a radial view, an increase in the axial dimension (L) of the vehicle drive device (100) due to the arrangement of the rolling bearing (B4) can be easily suppressed.

[0041] Further, it is preferable that the differential case (51) and the second ring gear (RG2) of the vehicle drive device (100) are integrally connected by welding.

[0042] According to this configuration, it is easy to construct a structure in which the differential case (51) of the differential gear device (5) for output is supported on the side of the planetary gear mechanism (4) by using the self-aligning by the engagement of the second ring gear (RG2).

Explanation of Reference Numerals

[0043] 1: Rotating electric machine, 2: First output member, 3: Second output member, 4: Planetary gear mechanism, 5: Differential gear device for output, 9: Case (non-rotating member), 9a: Inner wall surface, 12: Rotor, 41: Protrusion (connecting portion), 42: Support member (connecting portion), 43: Outer edge portion, 50: Differential gear mechanism, 51: Differential case, 94: Support wall portion (non-rotating member), 100: Vehicle drive device, A: Rotor axis (rotation axis of rotor), B4: Carrier bearing (rolling bearing), B5: Bush, CR: Carrier, L: Axial direction, PG1: First pinion gear, PG2: Second pinion gear, R: Radial direction, R2: Radial outside (outside in the radial direction), RG1: First ring gear, RG2: Second ring gear, SG: Sun gear, W1: First wheel, W2: Second wheel

Claims

1. A rotating electrical machine having a rotor, A first output member drivingly connected to a first wheel, A second output member drivingly connected to a second wheel, A planetary gear mechanism for reducing the rotation of the rotor, An output differential gear device including a differential case and a differential gear mechanism housed in the differential case for distributing the rotation transmitted from the planetary gear mechanism to the differential case to the first output member and the second output member, A vehicle drive device including a case housing the rotating electrical machine, the planetary gear mechanism, and the output differential gear device, The rotating electrical machine, the first output member, the second output member, the planetary gear mechanism, and the output differential gear device are arranged coaxially, The planetary gear mechanism includes a sun gear, a carrier, a first ring gear, and a second ring gear, The sun gear is connected to rotate integrally with the rotor, The first ring gear is connected to a non-rotating member, The second ring gear is connected to rotate integrally with the differential case, The carrier rotatably supports a first pinion gear and a second pinion gear that rotate integrally with each other, The first pinion gear meshes with the sun gear and the first ring gear, The second pinion gear has a smaller diameter than the first pinion gear and meshes with the second ring gear, Taking the direction along the rotation axis of the rotor as the axial direction and the direction perpendicular to the rotation axis as the radial direction, The differential case is supported rotatably with respect to the case in the radial direction via a bush disposed on the side opposite to the side where the planetary gear mechanism is located with respect to the differential gear mechanism and overlapping the differential gear mechanism in the axial view, The carrier is supported rotatably with respect to the case in the radial direction via a rolling bearing, and is disposed at a position overlapping the connecting portion between the first ring gear and the support wall portion in a radial view along the radial direction. A vehicle drive device.

2. The case includes a support wall portion disposed between the rotating electrical machine and the planetary gear mechanism in the axial direction, The non-rotating member is the support wall portion, The rolling bearing is supported by the support wall portion and is disposed at a position overlapping the connecting portion between the first ring gear and the support wall portion in a radial view along the radial direction. The vehicle drive device according to claim 1.

3. The second ring gear has a smaller diameter than the first ring gear, The carrier includes an outer edge portion located outside the second ring gear in the radial direction, The rolling bearing according to claim 1 is disposed at a position overlapping the second ring gear in a radial view along the radial direction between the inner wall surface of the case and the outer edge portion in the radial direction.

4. The vehicle drive device according to any one of claims 1 to 3, wherein the second ring gear and the differential case are integrally connected by welding.

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