Unit

Abstract

And the designability of the unit is improved. The unit includes a rotating electrical machine, an inverter located on an outer periphery of the rotating electrical machine, a first gear connected downstream of the rotating electrical machine, a second gear engaged with the first gear, a third gear connected downstream of the second gear via a shaft, and a fourth gear engaged with the third gear. In a radial view, the shaft has a portion overlapping with a stator of the rotating electrical machine, and in an axial view, the inverter has a portion overlapping with the second gear.

Description

Technical Field

[0001] The present invention relates to units. Background Art

[0002] A vehicle drive device having a counter gear mechanism for reducing speed is disclosed in Patent Document 1. The vehicle drive device transmits output torque of a rotary electric machine to a pair of wheels via a pair of output members, thereby driving the vehicle.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2021 / 131204 Summary of the invention

[0006] Technical problem to be solved by the invention

[0007] The rotating electric machine can be used in combination with a power transmission mechanism such as a speed reduction mechanism, a speed increase mechanism, and a speed change mechanism. However, when the rotating electric machine and the power transmission mechanism are not unitized but provided separately, an effective design cannot be achieved, and as a result, the overall size may increase. Therefore, a unit with higher design properties is desired.

[0008] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to improve the designability of a unit.

[0009] Technical solutions for solving technical problems

[0010] A unit according to a certain aspect of the present invention comprises: a rotating electric machine, an inverter located on the outer periphery of the rotating electric machine, a first gear connected to the downstream of the rotating electric machine, a second gear meshing with the first gear, a third gear connected to the downstream of the second gear via a shaft, and a fourth gear meshing with the third gear. In radial view, the shaft has a portion overlapping with a stator of the rotating electric machine, and in axial view, the inverter has a portion overlapping with the second gear.

[0011] Effects of the Invention

[0012] According to this method, the second gear and the third gear are configured separately relative to the axis passing through the outer periphery (peripheral space) of the rotating motor body. In other words, the second gear and the third gear are configured separately using the axis extending through the outer periphery of the rotating motor body. As a result, interference between the second gear and the fourth gear or accessories connected to the fourth gear (such as differential gears) can be avoided, and the axial dimension can be reduced. In addition, by making the inverter overlap with the second gear, that is, the more it overlaps with the second gear, the closer the inverter is to the axis, which can help to miniaturize the unit. Therefore, the design of the unit can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG. 1 is a schematic diagram showing the structure of a unit according to the present embodiment.

[0014] FIG. 2 is a first diagram illustrating the configuration of an inverter.

[0015] FIG. 3 is a second diagram illustrating the configuration of the inverter. DETAILED DESCRIPTION

[0016] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0017] FIG1 is a schematic diagram of the structure of a unit 100 of the present embodiment. The unit may be referred to as a motor unit (a unit having at least a motor) or a power transmission device (a device having at least a power transmission mechanism). A motor is a rotating electrical machine having an electric motor function and / or a generator function (at least one of the electric motor function and the generator function). The power transmission mechanism is, for example, a gear mechanism and / or a differential gear mechanism. A device (unit) having a motor and a power transmission mechanism is included in the concepts of both a motor unit and a power transmission device.

[0018] The unit 100 includes a housing 10, a rotating electric machine 20, a speed reduction mechanism 30, and a differential gear 40. The unit 100 is mounted on an electric vehicle, which is an electric vehicle. The housing 10 includes a first cover 11, a second cover 12, a plate 13, and a case 14. The rotating electric machine 20, the speed reduction mechanism 30, and the differential gear 40 are accommodated in the housing 10. The first cover 11 blocks the opening of the cylindrical case 14 from one axial side (the left side of the figure), and the second cover 12 blocks the opening of the case 14 from the other axial side via the plate 13. The rotating electric machine 20 is set in the case 14. The rotating electric machine 20 sets one axial side as the output side.

[0019] The rotating electric machine 20 includes a rotor 21, a stator 22, and a rotating shaft 23, and constitutes a driving source of the vehicle. The rotor 21 is disposed on the outer periphery of the rotating shaft 23. The stator 22 is disposed in the housing 14 and accommodates the rotor 21. The rotating shaft 23 protrudes from the rotor 21 to both sides in the axial direction and is supported by a bearing 51 disposed in the first housing 11 and a bearing 52 disposed in the plate 13.

[0020] The rotating shaft 23 has a hollow structure. The first transmission shaft 61 penetrates the rotating shaft 23 from one side in the axial direction. The first transmission shaft 61 further penetrates the plate body 13 and is installed on the differential gear 40. A bearing retaining hole is formed in the plate body 13 at the portion where the first transmission shaft 61 penetrates. In the bearing retaining hole, a bearing 52 is provided from one end side in the axial direction, and a bearing 55 is provided from the other end side in the axial direction.

[0021] The speed reduction mechanism 30 is a gear mechanism, and has: a first gear 31, a second gear 32, a third gear 33, a fourth gear 34, and a long shaft 35. The first gear 31 and the fourth gear 34 are arranged on the first axis AX1 together with the rotating motor 20. In other words, the rotating motor 20, the first gear 31 and the fourth gear 34 are arranged coaxially with respect to the first axis AX1. In other words, the arrangement of multiple main components (accessories, parts, etc.) on the Nth axis (N is a natural number) is the same as the arrangement of multiple main components coaxially with respect to the Nth axis. Similarly, the second gear 32 and the third gear 33 are arranged on the second axis AX2.

[0022] The first axis AX1 and the second axis AX2 both constitute the axis of the unit 100 and extend in the same direction. Therefore, the extension direction of the first axis AX1 and the second axis AX2 is equivalent to the axial direction of the unit 100. In other words, the axial direction refers to the axial direction of the rotating shaft of the accessories (such as motors, gear mechanisms, differential gear mechanisms) that constitute the unit. The radial direction of the unit 100 is a direction orthogonal to the first axis AX1 or the second axis AX2. The first axis AX1 constitutes the axis of the rotating shaft 23 and the differential gear 40, and the second axis AX2 constitutes the axis of the long axis 35.

[0023] The first gear 31 is connected to the downstream of the rotating motor 20. The downstream is the power output side, and with respect to the rotating motor 20, the rotor 21 and the stator 22 that generate power are used as reference. Therefore, the downstream of the rotating motor 20 can also be said to be the downstream of the stator 22. Alternatively, with respect to the positional relationship of power transmission, the rotating shaft 23 may not be understood as a main structural component of the rotating motor 20. With respect to the downstream being the power output side, the upstream is the power input side.

[0024] The first gear 31 is connected to the downstream of the rotating electric machine 20 so as to be transferable. The connection may also be a connection via other structures (e.g., a clutch or other gear mechanisms). The first gear 31 is disposed on the rotating shaft 23 closer to one axial side than the rotor 21 and disposed between the rotor 21 and the bearing 51. The first gear 31 is formed integrally with the rotating shaft 23.

[0025] The second gear 32 meshes with the first gear 31. The number of teeth of the second gear 32 is set larger than that of the first gear 31, and together with the first gear 31, the second gear 32 forms a first reduction gear. The second gear 32 is provided on the long shaft 35. The second gear 32 is formed integrally with the long shaft 35 by being pressed against the long shaft 35. The long shaft 35 extends along the rotating shaft 23 and passes through the outer periphery (peripheral space) of the stator 22.

[0026] Therefore, the major axis 35 has a portion that overlaps with the stator 22 in the radial view. This portion overlaps with the stator 22 in the radial view along the plane including the first axis AX1 and the second axis AX2, for example. Overlapping in a specified direction viewing angle including a radial view or an axial view means overlapping in a specified direction, indicating that a plurality of main components are arranged side by side in a specified direction. Accordingly, the drawings illustrate a situation where a plurality of main components are arranged side by side in a specified direction, and it can also be regarded as having content in the specification that explains the situation where a plurality of main components overlap in a specified direction viewing angle.

[0027] The long shaft 35 extends through the plate 13 toward the other end axially beyond the stator 22. The plate 13 has an insertion hole for the long shaft 35 in the portion through which the long shaft 35 passes. The long shaft 35 is supported by a bearing 53 provided in the first housing 11 and a bearing 54 provided in the second housing 12.

[0028] The third gear 33 is provided on the long shaft 35. The long shaft 35 is located downstream of the second gear 32, and the third gear 33 is connected to the downstream of the second gear 32 via the long shaft 35. The third gear 33 is connected to the downstream of the second gear 32 via a portion of the long shaft 35. The third gear 33 is provided on the long shaft 35 at a portion extending further to the other axial side than the stator 22. This portion is a portion closer to the other axial end side than the plate body 13. The third gear 33 is provided in a portion between the stator 22 and the bearing 54, and is formed integrally with the long shaft 35.

[0029] The second gear 32 is arranged on one end side of the axial direction, and the third gear 33 is arranged on the other end side of the axial direction on the long shaft 35. That is, the second gear 32 and the third gear 33 are arranged at both ends relative to the long shaft 35, and are separated and arranged by the long shaft 35 extending through the outer periphery of the stator 22. As a result, it is possible to avoid interference between the second gear 32 and the fourth gear 34 or the differential gear 40, an example of an accessory connected to the fourth gear 34, and reduce the axial dimension of the unit 100. For example, compared with the case where the first gear 31 to the fourth gear 34 are concentratedly arranged on one side of the axial direction relative to the stator 22, the axial dimension can be reduced. The second gear 32 and the third gear 33 are arranged between the bearing 53 and the bearing 54 in the axial direction.

[0030] The fourth gear 34 meshes with the third gear 33. The fourth gear 34 is a final gear, and is provided on the differential gear 40. The power from the rotary electric machine 20 is transmitted from the fourth gear 34 to the differential gear 40. Therefore, the differential gear 40 is connected to the downstream of the fourth gear 34.

[0031] The fourth gear 34 has a larger number of teeth than the third gear 33, and together with the third gear 33, it forms a second reduction gear. Therefore, in the reduction mechanism 30, two-speed reduction is performed using the first gear 31 and the second gear 32, and the third gear 33 and the fourth gear 34. Thus, when ensuring the reduction ratio, the reduction gear diameter can be reduced compared to the case of reducing the speed by one gear. As a result, it is possible to alleviate the design limitation that the unit 100 is limited to be compact because the distance between axes corresponding to the larger reduction gear diameter must be ensured.

[0032] The differential gear 40 is a differential gear mechanism, and is disposed on the first axis AX1. The differential gear 40 has a differential case 41 and a differential portion 42. The differential case 41 is supported by a bearing 55 provided on the plate body 13 and a bearing 56 provided on the second cover body 12, and rotates together with the fourth gear 34. The fourth gear 34 is coaxially fixed to the outer wall portion of the differential case 41, and the differential case 41 accommodates the differential portion 42. The differential portion 42 distributes the power input to the differential case 41 via the fourth gear 34 and outputs it to each driving wheel in the left and right directions of the vehicle.

[0033] The differential gear 40 protrudes in a direction away from the stator 22 relative to the fourth gear 34. The differential gear 40 protrudes in such a way that a portion that further protrudes in the axial direction from the fourth gear 34 is used as a protruding portion. Therefore, in other words, the differential gear 40 protrudes in a direction further away from the fourth gear 34 than in a direction approaching the stator 22, and is arranged in a direction approaching and away from the stator 22 relative to the fourth gear 34.

[0034] Thus, compared with the case where the differential gear 40 further protrudes in the opposite direction, the fourth gear 34 can be arranged closer to the stator 22, thereby suppressing the growth of the major axis 35. As a result, the influence of the distortion of the major axis 35 can be reduced, compared with the case where the influence of the distortion increases as the major axis 35 becomes longer. In addition, the expansion of the axial dimension of the unit 100 can also be suppressed.

[0035] With respect to the differential gear 40 thus arranged, the bearing 54 supporting the long shaft 35 overlaps with the differential gear 40 in a radial view (e.g., in a radial view along a plane including the first axis AX1 and the second axis AX2). Therefore, it is also possible to reduce the axial dimension of the unit 100 on a straight line passing through the second axis AX2.

[0036] The differential portion 42 is provided with a first transmission shaft 61 from one axial side and a second transmission shaft 62 from the other axial side. The power from the rotating electric machine 20 is transmitted from the differential portion 42 to the driving wheel on one side via the first transmission shaft 61, and is transmitted to the driving wheel on the other side via the second transmission shaft 62. The first transmission shaft 61 is longer than the second transmission shaft 62, thereby being able to obtain a distance between the driving wheel and the differential gear 40, thereby being able to suppress a bending angle. The first transmission shaft 61 is supported by a bearing 57 provided on the first cover 11.

[0037] The fourth gear 34 can also be understood as a part of the differential gear 40. That is, the fourth gear 34 can be understood as a main structural component of the differential gear 40. In this case, it can also be understood that the differential gear 40 is connected downstream of the fourth gear 34 in the form of connecting a part of the differential gear 40 including the differential portion 42 that outputs the power from the rotary electric machine 20 to the downstream of the fourth gear 34.

[0038] FIG. 2 and FIG. 3 are explanatory diagrams of the configuration of the inverter 70. In FIG. 2, the appearance of the unit 100 is shown in a radial view without showing the housing 10. FIG. 3 shows the configuration of the main structure required for the explanation in an axial view (when viewed from the right side of FIG. 2). As shown in FIG. 2 and FIG. 3, the unit 100 also has an inverter 70. The inverter 70 can be arranged on the outside of the housing 10. The inverter 70 can also be accommodated in the housing 10. The inverter 70 has a portion that overlaps with the second gear 32 in an axial view. Therefore, the more the inverter 70 overlaps with the second gear 32, the closer the inverter 70 is arranged to the major axis 35, and as a result, the unit 100 can be miniaturized.

[0039] 3 , for example, the major axis 35 has a portion overlapping the stator 22. The view A is an example of a predetermined direction viewing angle, and the predetermined direction viewing angle illustrated by the view A is, for example, a radial view along a plane including the first axis AX1 and the second axis AX2.

[0040] In addition, the major axis 35 and the inverter 70 deviate from each other in the predetermined direction of view exemplified by the view A. Deviating from the predetermined direction of view means that the plurality of main components are not arranged in parallel in the predetermined direction. According to the above description, the drawings illustrate the situation where the plurality of main components are not arranged in parallel in the predetermined direction, which can be regarded as the content in the specification that explains the situation where the plurality of main components deviate from the predetermined direction of view.

[0041] By making the long axis 35 disposed on the outer periphery of the stator 22 and the inverter 70 deviate from each other in the predetermined direction as exemplified by the view A, the inverter 70 is disposed not in the direction in which the main body of the rotating electrical machine 20 and the long axis 35 are parallel, but in a direction offset from the direction. As a result, it is possible to suppress the expansion of the dimension in the direction in which the stator 22 and the long axis 35 are parallel. By increasing the gear diameter of the second gear 32, it is easy to secure a space for arranging the inverter 70.

[0042] Next, the main effects of this embodiment will be described.

[0043] (1) The unit 100 includes a rotating electrical machine 20, an inverter 70 located on the outer periphery of the rotating electrical machine 20, a first gear 31 connected to the downstream of the rotating electrical machine 20, a second gear 32 meshing with the first gear 31, a third gear 33 connected to the downstream of the second gear 32 via a long shaft 35, and a fourth gear 34 meshing with the third gear 33. In radial view, the long shaft 35 has a portion overlapping with the stator 22 of the rotating electrical machine 20, and in axial view, the inverter 70 has a portion overlapping with the second gear 32.

[0044] According to such a structure, the second gear 32 and the third gear 33 are configured separately relative to the long axis 35 passing through the outer periphery of the stator 22. That is, the second gear 32 and the third gear 33 are configured separately using the long axis 35 extending through the outer periphery of the stator 22. As a result, interference between the second gear 32 and the fourth gear 34 or accessories (such as the differential gear 40) connected to the fourth gear 34 can be avoided, and the axial dimension can be reduced. In addition, by overlapping the inverter 70 with the second gear 32, that is, the closer the inverter 70 is to the long axis 35, the more it overlaps with the second gear 32, which can contribute to the miniaturization of the unit 100. Therefore, the design of the unit 100 can be improved.

[0045] (2) In the unit 100, in a predetermined direction of view exemplified by the arrow view A, the major axis 35 has a portion overlapping the stator 22, and the major axis 35 and the inverter 70 are offset from each other. According to such a structure, the inverter 70 can be arranged in a direction offset from the stator 22 and the major axis 35, rather than in a direction parallel to the stator 22 and the major axis 35. As a result, the expansion of the dimension in this direction can be suppressed.

[0046] (3) In the unit 100, the rotating electrical machine 20, the first gear 31, and the fourth gear 34 are arranged on the first axis AX1, and the second gear 32 and the third gear 33 are arranged on the second axis AX2. According to such a structure, the gears of the speed reduction mechanism 30 are arranged coaxially with respect to the first axis AX1 and the second axis AX2, thereby making the unit 100 compact in the radial direction. In addition, by also arranging the rotating electrical machine 20 on the first axis AX1, further compactness can be achieved. In particular, when the outer diameter of the stator 22 is close to the gear diameter of the fourth gear 34 provided on the differential gear 40, the above arrangement is conducive to compactness.

[0047] (4) The unit 100 further includes a differential gear 40 connected to the downstream of the fourth gear 34. The differential gear 40 is arranged on the first axis AX1 and protrudes in a direction away from the stator 22 relative to the fourth gear 34. According to such a structure, compared with the case where the differential gear 40 protrudes in the opposite direction, the growth of the major axis 35 can be suppressed. Therefore, the influence of the distortion of the major axis 35 can be reduced, and the expansion of the axial dimension of the unit 100 can also be suppressed.

[0048] (5) In the unit 100, the bearing 54 supporting the major shaft 35 overlaps with the differential gear 40 in the radial view. According to such a structure, the axial dimension of the unit 100 on the straight line passing through the second axis line AX2 can also be reduced.

[0049] Although the embodiments of the present invention have been described above, the above embodiments merely represent a part of application examples of the present invention and are not intended to limit the technical scope of the present invention to the specific structures of the above embodiments.

[0050] Description of Reference Numerals

[0051] 10 housing; 20 rotating motor; 21 rotor; 22 stator; 23 rotating shaft; 30 reduction mechanism; 31 first gear; 32 second gear; 33 third gear; 34 fourth gear; 35 long shaft (shaft); 40 differential gear; 54 bearing (bearing); 70 inverter; 100 unit; AX1 first axis; AX2 second axis.

Claims

1. A unit, characterized in that have: Rotating electrical machines; an inverter located at the periphery of the rotating electrical machine; A first gear connected to the downstream of the rotating motor; a second gear meshing with the first gear; A third gear connected to the downstream of the second gear via a shaft; a fourth gear meshing with the third gear; In radial view, the shaft has a portion overlapping with the stator of the rotating electrical machine, In an axial view, the inverter has a portion overlapping with the second gear.

2. The unit according to claim 1, characterized in that In a predetermined direction viewing angle, the shaft has a portion overlapping with the stator, and the shaft and the inverter are offset from each other.

3. The unit according to claim 1, characterized in that The rotating motor, the first gear, and the fourth gear are arranged on a first axis. The second gear and the third gear are arranged on a second axis.

4. The unit according to claim 3, characterized in that further having a differential gear connected downstream of the fourth gear, The differential gear is arranged on the first axis. The differential gear protrudes in a direction away from the stator relative to the fourth gear.

5. The unit according to claim 4, characterized in that In a radial view, the bearings supporting the shaft overlap with the differential gear.

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