Unit

Abstract

[Problem] To provide a unit capable of contributing to miniaturization. [Solution] This unit comprises: a rotating electrical machine; a planetary gear mechanism that is connected downstream from the rotating electrical machine; a first gear that is connected downstream from the planetary gear mechanism; a second gear that engages the first gear; and a third gear that is connected downstream from the second gear. The rotating electrical machine, the planetary gear mechanism, and the first gear are disposed at a first shaft. The second gear and the third gear are disposed at a second shaft. The third gear includes a portion interposed between the planetary gear mechanism and the second gear.

Description

Technical Field

[0001] The present invention relates to a unit.

Background Art

[0002] Patent Document 1 discloses a unit provided with a speed reduction mechanism.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a unit that can contribute to miniaturization.

Means for Solving the Problems

[0005] According to an aspect of the present invention, there is provided a unit including a rotating electrical machine, a planetary gear mechanism connected downstream of the rotating electrical machine, a first gear connected downstream of the planetary gear mechanism, a second gear meshing with the first gear, and a third gear connected downstream of the second gear, wherein the rotating electrical machine, the planetary gear mechanism, and the first gear are arranged on a first axis, the second gear and the third gear are arranged on a second axis, and the third gear has a portion sandwiched between the planetary gear mechanism and the second gear.

Effects of the Invention

[0006] According to an aspect of the present invention, it is possible to contribute to miniaturization of the unit.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

[0008] Hereinafter, embodiments of the present invention (hereinafter simply referred to as the present embodiments) will be described with reference to the accompanying drawings.

[0009] First, the unit 1 according to the present embodiment will be described with reference to FIGS. 1 and 2. In the present specification, the same reference numerals are given to the same elements throughout.

[0010] FIG. 1 is a schematic configuration diagram of the unit 1 according to the present embodiment. FIG. 2 is a longitudinal sectional view showing the positional relationship between the inverter 4 and the planetary gear mechanism 51.

[0011] The unit 1 shown in FIGS. 1 and 2 is used for driving the drive wheels (not shown) of a vehicle, but is not limited thereto, and may be used for driving, for example, an electric product. The unit 1 is also called a motor unit (a unit having at least a motor), a power transmission device (a device having at least a power transmission mechanism (for example, a gear mechanism and / or a differential gear mechanism, etc.)). Note that a device (unit) having a motor and a power transmission mechanism belongs to both the concepts of a motor unit and a power transmission device. Specifically, the unit 1 includes a housing 2, a motor 3 as a rotating electric machine, an inverter 4, a reduction gear group 5 as a power transmission mechanism, and a drive shaft 6.

[0012] The housing 2 is a housing member that houses the motor 3, the inverter 4, the reduction gear group 5, and the drive shaft 6. The housing 2 is composed of one or more cases. Specifically, the housing 2 is composed of a first case 21, a second case 22, a third case 23 as a third wall portion, a fourth case 24, and a fifth case 25 (see FIG. 2).

[0013] The first case 21 is a 3-in-1. A 3-in-1 means a form in which a part of the motor case that houses the motor 3 and the drive shaft 6 and a part of the inverter case that houses the inverter 4 are integrally formed.

[0014] The first case 21 has a cylinder 211 provided to open at the front end as at least one end, a front flange 212 provided to protrude to the outer peripheral side at the front end of the cylinder 211, a rear flange 213 provided to protrude to the outer peripheral side at the rear end as the other end of the cylinder 211, and a support frame 214 disposed on the inner peripheral side of the cylinder 211 so as to be located at the rear end of the cylinder 211. Here, the axial direction X means the axial direction X of the rotation axis of the components constituting the unit 1. The components are, for example, the motor 3, the gear mechanism, and the differential gear mechanism.

[0015] The support frame 214 has an annular wall 214a as a first wall portion that fixes the ring gear 513 of the planetary gear mechanism 51 of the reduction gear group 5 described later, a first support wall 214b that is located on the front end side of the cylinder 211 with respect to the annular wall 214a and is arranged to support the bearing B1, and a second support wall 214c as a second wall portion that is arranged side by side with the annular wall 214a in the lateral direction Y as the first radial direction and supports the bearing B2 as the first bearing.

[0016] The first support wall 214b supports the rear end as the other end of the rotation shaft 31 of the motor 3 described later via the bearing B1. The second support wall 214c rotatably supports the front end as one end of the differential gear 56 as the differential gear mechanism of the reduction gear group 5 described later (specifically, the front end of the differential case 561 of the differential gear 56 described later) via the bearing B2.

[0017] Note that the annular wall 214a, the first support wall 214b, and the second support wall 214c are integrally formed. Thereby, an increase in the number of parts can be suppressed without forming the parts constituting the support frame 214 individually.

[0018] The second case 22 is connected to the front end of the cylinder 211 of the first case 21. Specifically, the outer periphery of the second case 22 is connected to the front flange 212 by bolt tightening. Also, the second case 22 supports both of the bearings B3 and B4. And the second case 22 rotatably supports both the front end as one end of the rotating shaft 31 of the motor 3 and the front end as one end of the drive shaft 6 (specifically, the first drive shaft 61 that constitutes the drive shaft 6) via the bearing B3 and the bearing B4, respectively.

[0019] The third case 23 is disposed on the inner peripheral side of the cylinder 211 so as to be located at the rear end of the cylinder 211. The third case 23 is formed separately from the support frame 214. Also, the third case 23 is connected to the support frame 214. Specifically, the outer periphery of the third case 23 is connected to the rear end of the annular wall 214a of the support frame 214 by bolt tightening so as to be located in the region within the first case 21.

[0020] The third case 23 supports the bearing B5 as the second bearing that supports the front end as one end of the first shaft 7 that rotates integrally with the first gear 52 of the reduction gear group 5 described later, and the bearing B6 as the third bearing that supports the front end as one end of the second shaft 8 that rotates integrally with the third gear 54 of the reduction gear group 5 described later. And the third case 23 rotatably supports the front end of the first shaft 7 and the front end of the second shaft 8 via the bearing B5 and the bearing B6, respectively.

[0021] The fourth case 24 houses the reduction gear group 5. The fourth case 24 is composed of a bottomed cylinder that opens at the front end as one end and is closed at the rear end as the other end. Also, the fourth case 24 is connected to the rear end of the cylinder 211. Specifically, the outer periphery of the front end of the fourth case 24 is connected to the rear flange 213 by bolt tightening.

[0022] The fourth case 24 supports a bearing B7 that supports the rear end as the other end of the first shaft 7, a bearing B8 that supports the rear end as the other end of the second shaft 8, and a bearing B9 that supports the rear end (specifically, the rear end of the differential case 551) as the other end of the differential gear 56. And the fourth case 24 rotatably supports the rear end of the first shaft 7, the rear end of the second shaft 8, and the rear end of the differential gear 56 via the bearing B7, the bearing B8, and the bearing B9, respectively.

[0023] The bearing B3, the bearing B1, the bearing B5, and the bearing B7 are arranged in order in the axial direction X from the front side to the rear side. The bearing B6 and the bearing B8 are arranged in order in the axial direction X from the front side to the rear side. The bearing B4, the bearing B2, and the bearing B9 are arranged in order in the axial direction X from the front side to the rear side.

[0024] The bearing B2 is arranged to be located between the bearing B1 and the bearing B5. The bearing B9 is arranged to be located between the bearing B5 (or B6) and the bearing B7 (or B8).

[0025] As shown in FIG. 2, the fifth case 25 closes the opening of the inverter accommodation chamber S1 that is surrounded by the cylinder 211, the front flange 212, and the rear flange 213 of the first case 21 and accommodates the inverter 4. The fifth case 25 is connected to the front flange 212, the rear flange 213, etc. by bolt tightening.

[0026] The motor 3 is a rotating electric machine having a motor function and / or a generator function. Further, the motor 3 includes a rotating shaft 31 rotatably supported by the first case 21 and the second case 22 via the bearings B3 and B1, a rotor 32 located on the outer peripheral side of the rotating shaft 31 and rotating integrally with the rotating shaft 31, and a stator 33 fixed to the inner peripheral side of the cylinder 211 so as to be located on the outer peripheral side of the rotor 32.

[0027] The inverter 4 is a controller for controlling the drive of the motor 3. The inverter 4 is housed in the inverter housing chamber S1 so as to extend along the axial direction X.

[0028] The reduction gear group 5 is a power transmission mechanism that reduces the power of the motor 3 and transmits it to the drive shaft 6, and is composed of a plurality of gears. The reduction gear group 5 is power-connected downstream of the motor 3 and power-connected upstream of the drive shaft 6. Further, the reduction gear group 5 is housed in the reduction gear group housing chamber S2 formed by the connected first case 21, third case 23, and fourth case 24.

[0029] As shown in FIG. 1, the reduction gear group 5 has a planetary gear mechanism 51 as a first element or a second element, a first gear 52, a second gear 53, a third gear 54, a fourth gear 55, and a differential gear 56, which are arranged in order from upstream to downstream. And the power from the motor 3 is transmitted to the drive shaft 6 through the planetary gear mechanism 51, the first gear 52, the second gear 53, the third gear 54, the fourth gear 55, and the differential gear 56 in sequence.

[0030] Hereinafter, the second element (component, part, etc.) connected to the first element (component, part, etc.) / the second element (component, part, etc.) connected downstream of the first element (component, part, etc.) / the second element (component, part, etc.) connected upstream of the first element (component, part, etc.) means that the first element and the second element are power-transmittably connected. The power input side is the upstream, and the power output side is the downstream. Also, they may be connected via other mechanisms (for example, clutches, other gear mechanisms, etc.).

[0031] The planetary gear mechanism 51 is connected downstream of the motor 3. The planetary gear mechanism 51 is housed on the inner peripheral side of the annular wall 214a so that the front side and the rear side face the first support wall 214b and the third case 23, respectively. That is, the planetary gear mechanism 51 is arranged in a region surrounded by the annular wall 214a, the first support wall 214b, and the third case 23.

[0032] As a result, after the planetary gear mechanism 51 is attached to the annular wall 214a, the third case 23, the first gear 52, the second gear 53, the third gear 54, etc., which are separate from the first case 21, can be attached, so that a case structure that is easy to assemble can be achieved.

[0033] Further, since the planetary gear mechanism 51 is located only in the region within the first case 21 and not in the region within the fourth case 24, the first gear 52 and the second gear 53 can be arranged closer to the motor 3 side in the axial direction X compared to the configuration in which the planetary gear mechanism 51 is arranged in the region within the fourth case 24. As a result, it is possible to contribute to the miniaturization of the unit 1 (particularly in the axial direction X).

[0034] Also, in a radial view, the planetary gear mechanism 51 overlaps with the inverter accommodation chamber S1. That is, the planetary gear mechanism 51 and the inverter accommodation chamber S1 are arranged side by side in the vertical direction Z as the second radial direction orthogonal to the lateral direction Y.

[0035] In other words, in a radial view, the inverter accommodation chamber S1 has a portion that overlaps with the planetary gear mechanism 51. As a result, a space is generated outside the planetary gear mechanism 51 in the radial direction of the space where the planetary gear mechanism 51 is arranged, and by forming the inverter accommodation chamber S1 in the space, the space can be effectively utilized, so that it is possible to contribute to the miniaturization of the entire unit 1.

[0036] The planetary gear mechanism 51 includes a sun gear 511, a carrier 512, and a ring gear 513. Between the sun gear 511 and the ring gear 513, a pinion gear group 514 that meshes with both the sun gear 511 and the ring gear 513 is arranged. The ring gear 513 is fixed to the inner circumference of the annular wall 214a in a non-rotatable manner. The pinion gear group 514 is rotatably supported by the carrier 512.

[0037] The sun gear 511 is connected to the rear end of the rotating shaft 31 so as to rotate integrally with the rotating shaft 31. The carrier 512 is connected to the front end of the first shaft 7 so as to rotate integrally with the first shaft 7. The first shaft 7 is rotatably supported by the third case 23 and the fourth case 24 via bearings B5 and B7. The axes of the rotating shaft 31 and the first shaft 7 are both the axis C1 as the first axis. In this way, by arranging the planetary gear mechanism 51 coaxially with the rotating shaft 31 of the motor 3, a high reduction ratio can be achieved, and the unit 1 can be prevented from expanding in the radial direction compared with a configuration in which the planetary gear mechanism 51 is arranged non - coaxially with the rotating shaft 31.

[0038] The first gear 52 is connected downstream of the planetary gear mechanism 51 so as to be closer to the bearing B7 than to the bearing B5. The first gear 52 is formed on the outer periphery of the first shaft 7 so as to rotate integrally with the first shaft 7. The motor 3, the planetary gear mechanism 51, and the first gear 52 are arranged coaxially with the axis C1. Thereby, by providing the planetary gear mechanism 51 coaxially between the first gear 52 as the first - stage gear and the motor 3, the unit 1 can be prevented from expanding in the radial direction.

[0039] The second gear 53 meshes with the first gear 52. The second gear 53 is set to have more teeth than the first gear 52 and constitutes the first reduction gear stage together with the first gear 52. The second gear 53 is connected to the outer periphery of the second shaft 8 so as to rotate integrally with the second shaft 8. The second shaft 8 is parallel to the first shaft 7 and is rotatably supported by the third case 23 and the fourth case 24 via bearings B6 and B8 so as to be located between the first shaft 7 and the drive shaft 6.

[0040] The third gear 54 is connected downstream of the second gear 53 so as to be closer to the bearing B6 than to the bearing B8. The third gear 54 is formed on the outer periphery of the second shaft 8 so as to rotate integrally with the second shaft 8. That is, the second gear 53 and the third gear 54 are arranged coaxially with the axis C2 of the second shaft 8 as the second axis.

[0041] Further, the third gear 54 is positioned between the planetary gear mechanism 51 and the second gear 53. That is, the third gear 54 has a portion sandwiched between the planetary gear mechanism 51 and the second gear 53. Thereby, compared with a configuration in which the second gear 53 is positioned between the planetary gear mechanism 51 and the third gear 54, expansion of the unit 1 in the axial direction X and the radial directions Y, Z can be suppressed.

[0042] In the axial direction view, the planetary gear mechanism 51 overlaps with the second gear 53 and the third gear 54. That is, the planetary gear mechanism 51, the second gear 53, and the third gear 54 are arranged side by side in the axial direction X.

[0043] In other words, in the axial direction view, the planetary gear mechanism 51 has a portion overlapping with the second gear 53 and the third gear 54. Thereby, since the space of the reduction gear group accommodation chamber S2 can be effectively utilized, it is possible to contribute to downsizing of the entire unit 1.

[0044] The fourth gear 55 meshes with the third gear 54. The fourth gear 55 is set to have more teeth than the third gear 54, and together with the third gear 54, constitutes a second reduction gear stage. In the reduction gear group 5, two-stage reduction is performed by the first gear 52 and the second gear 53, and the third gear 54 and the fourth gear 55. Thereby, in securing the reduction ratio, the diameter of the reduction gear can be made smaller compared with single-stage reduction.

[0045] The differential gear 56 is connected downstream of the fourth gear 55. The differential gear 56 has a differential case 561 and a differential portion 562.

[0046] The differential case 561 houses the differential portion 562. The differential case 561 is rotatably supported by the first case 21 and the fourth case 24 via bearings B2 and B9. Further, the differential case 561 is connected to the inner periphery of the fourth gear 55 so as to rotate integrally with the fourth gear 55.

[0047] The differential unit 562 transmits the power transmitted to the differential case 561 via the fourth gear 55 to the drive shaft 6.

[0048] The drive shaft 6 rotates integrally with the drive wheels of the vehicle. The drive shaft 6 is connected downstream of the differential gear 56 so as to be parallel to the rotation axis 31. Further, the drive shaft 6 has a first drive shaft 61 connected to one drive wheel and a second drive shaft 62 connected to the other drive wheel. The axis of the first drive shaft 61 and the axis of the second drive shaft 62 are both the axis C3 as the third axis.

[0049] And the fourth gear 55 and the differential gear 56 are coaxially arranged on the axis C3. The differential gear 56 is arranged closer to the planetary gear mechanism 51 side than the fourth gear 55. That is, the differential gear 56 has a portion located between the planetary gear mechanism 51 and the fourth gear 55.

[0050] As a result, a space is generated outside the radial direction of the space where the planetary gear mechanism 51 is arranged, and by arranging the differential gear 56 in this space, the space can be effectively utilized, so that it can contribute to the miniaturization of the unit 1.

[0051] In the radial view, the differential gear 56 overlaps with the third case 23. That is, the differential gear 56 and the third case 23 are arranged side by side in the lateral direction Y.

[0052] In other words, in the radial view, the differential gear 56 has a portion overlapping with the third case 23. As a result, an opening is generated as a space surrounded by the first case 21 and the third case 23 on the radially outer side of the space where the third case 23 is disposed. By forming the differential gear 56 to pass through the opening (that is, by disposing the differential gear 56 in both the region within the first case 21 and the region within the fourth case 24), the space formed by the opening can be effectively utilized. Therefore, compared with a configuration in which the differential gear 56 is disposed only in the region within the fourth case 24, it is possible to contribute to downsizing of the unit 1 (particularly in the axial direction X).

[0053] By increasing the overall gear ratio of the reduction gear group 5 (since the gear ratio and the reduction ratio are in an inverse proportional relationship, the reduction ratio becomes smaller), the maximum torque required for the motor 3 can be reduced, which can contribute to downsizing of the motor 3. In addition, in order to increase the gear ratio, a planetary gear mechanism 51 is added to increase the number of reduction stages. Therefore, the differential diameter (proportional to the diameter of the fourth gear 55 as a reduction gear that rotates integrally with the differential gear 56) can be reduced, making the layout easier.

[0054] (Function and Effect) Next, the main function and effect of the present embodiment will be described.

[0055] (1) The unit 1 according to the present embodiment includes a motor 3 (rotary electric machine), a planetary gear mechanism 51 connected downstream of the motor 3 (rotary electric machine), a first gear 52 connected downstream of the planetary gear mechanism 51, a second gear 53 meshing with the first gear 52, and a third gear 54 connected downstream of the second gear 53. The motor 3 (rotary electric machine), the planetary gear mechanism 51, and the first gear 52 are disposed on the axis C1 (first axis), the second gear 53 and the third gear 54 are disposed on the axis C2 (second axis), and the third gear 54 has a portion sandwiched between the planetary gear mechanism 51 and the second gear 53.

[0056] According to this configuration, by coaxially providing the planetary gear mechanism 51 between the first gear 52 as the first-stage gear and the motor 3, it is possible to suppress the radial expansion of the unit 1. Further, since the third gear 54 is disposed sandwiched between the planetary gear mechanism 51 and the second gear 53, it is possible to suppress the expansion of the unit 1 in the axial direction X and the radial directions Y and Z. As a result, it is possible to contribute to the miniaturization of the unit 1.

[0057] (2) The unit 1 further includes a fourth gear 55 that meshes with the third gear 54, a differential gear 56 connected downstream of the fourth gear 55, and a drive shaft 6 connected downstream of the differential gear 56. The fourth gear 55 and the differential gear 56 are disposed on the axis C3, and the differential gear 56 is disposed closer to the planetary gear mechanism 51 than the fourth gear 55.

[0058] According to this configuration, a space is generated outside the radial direction of the space in which the planetary gear mechanism 51 is disposed, and by disposing the differential gear 56 in the space, the space can be effectively utilized, so that it is possible to contribute to the miniaturization of the unit 1.

[0059] (3) The unit 1 further includes an annular wall 214a (first wall portion) that fixes the ring gear 513 of the planetary gear mechanism 51, and a second support wall 214c (second wall portion) that supports a bearing B2 (first bearing) on which the differential gear 56 is supported. The annular wall 214a (first wall portion) and the second support wall 214c (second wall portion) are integrally formed.

[0060] According to this configuration, it is possible to suppress an increase in the number of parts without separately forming the parts constituting the support frame 214.

[0061] (4) Unit 1 further includes a third case 23 (third wall portion) facing the planetary gear mechanism 51. The third case 23 (third wall portion) is formed separately from the annular wall 214a (first wall portion) and the second support wall 214c (second wall portion). The third case 23 (third wall portion) supports a bearing B5 (second bearing) that supports the first shaft 7 that rotates integrally with the first gear 52, and a bearing B6 (third bearing) that supports the second shaft 8 that rotates integrally with the third gear 54.

[0062] According to this configuration, after attaching the planetary gear mechanism 51 to the annular wall 214a, it is possible to attach the third case 23, the first gear 52, the second gear 53, the third gear 54, etc., which are separate from the first case 21. Therefore, a case structure that is easy to assemble can be achieved.

[0063] (5) Unit 1 further includes an inverter 4. In a radial view, the inverter housing chamber S1 that houses the inverter 4 has a portion that overlaps with the planetary gear mechanism 51.

[0064] According to this configuration, a space is generated on the radially outer side of the space where the planetary gear mechanism 51 is arranged. By forming the inverter housing chamber S1 in this space, the space can be effectively utilized, which can contribute to downsizing the entire Unit 1.

[0065] As described above, the embodiments of the present invention have been explained. However, the above embodiments merely show a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

Explanation of Reference Numerals

[0066] 1 Unit 3 Motor (Rotating Electric Machine) 4 Inverter 6 Drive Shaft 7 First Shaft 8 Second Shaft 23 Third Case (Third Wall Portion) 51 Planetary Gear Mechanism 52 First Gear 53 Second gear 54 Third gear 55 Fourth gear 56 Differential gear 214a Annular wall (first wall portion) 214c Second support wall (second wall portion) B2 Bearing (first bearing) B5 Bearing (second bearing) B6 Bearing (third bearing) C1 Axis (first axis) C2 Axis (second axis) C3 Axis (third axis) S1 Inverter accommodation chamber

Claims

1. A rotating electrical machine, A planetary gear mechanism connected downstream of the rotating electrical machine, A first gear connected downstream of the planetary gear mechanism, A second gear meshing with the first gear, A third gear connected downstream of the second gear, and comprising: The rotating electrical machine, the planetary gear mechanism, and the first gear are arranged on a first axis, The second gear and the third gear are arranged on a second axis, The third gear has a portion sandwiched axially between the ring gear of the planetary gear mechanism and the second gear, The third gear has a portion overlapping the ring gear in an axial view, Unit.

2. A fourth gear meshing with the third gear, A differential gear connected downstream of the fourth gear, A drive shaft connected downstream of the differential gear, further comprising: The fourth gear and the differential gear are arranged on a third axis, The differential gear is arranged closer to the planetary gear mechanism side than the fourth gear, The unit according to claim 1.

3. A first wall portion for fixing the ring gear of the planetary gear mechanism, A second wall portion for supporting a first bearing supporting the differential gear, further comprising: The first wall portion and the second wall portion are integrally formed, The unit according to claim 2.

4. Further comprising a third wall portion facing the planetary gear mechanism, The third wall portion is formed separately from the first wall portion and the second wall portion, The third wall portion supports a second bearing for supporting a first shaft that rotates integrally with the first gear and a third bearing for supporting a second shaft that rotates integrally with the third gear, The unit according to claim 3.

5. Further comprising an inverter, In a radial view, an inverter housing chamber for housing the inverter has a portion overlapping the planetary gear mechanism, The unit according to any one of claims 1 to 4.

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