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

unit

[0001] The present invention relates to a unit.

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

[0003] Japanese Patent Application Laid-Open No. 2022-33113

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

[0005] According to one aspect of the present invention, there is provided a unit comprising a rotating electric machine, a planetary gear mechanism connected downstream of the rotating electric 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 electric machine, the planetary gear mechanism, and the first gear are arranged on a first shaft, the second gear and the third gear are arranged on a second shaft, and the third gear has a portion sandwiched between the planetary gear mechanism and the second gear.

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

[0007] Fig. 1 is a schematic diagram of a unit according to this embodiment, and Fig. 2 is a vertical cross-sectional view showing the positional relationship between the inverter and the planetary gear mechanism.

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

[0009] First, a unit 1 according to this embodiment will be described with reference to Figures 1 and 2. Note that in this specification, the same elements are denoted by the same reference numerals throughout.

[0010] Fig. 1 is a schematic diagram of a unit 1 according to this embodiment. Fig. 2 is a vertical cross-sectional view showing the positional relationship between an inverter 4 and a planetary gear mechanism 51.

[0011] 1 and 2 is used to drive the drive wheels (not shown) of a vehicle, but is not limited thereto and may be used to drive, for example, an electrical appliance. 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 (e.g., a gear mechanism and / or a differential gear mechanism)), etc. Note that a device (unit) having a motor and a power transmission mechanism falls under the concepts of both 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, and a group of reduction gears 5 and a drive shaft 6 as a power transmission mechanism.

[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 made up of one or more cases. Specifically, the housing 2 is made up of a first case 21, a second case 22, and a third case 23, a fourth case 24, and a fifth case 25 (see FIG. 2 ) that serve as a third wall portion.

[0013] The first case 21 is a 3-in-1 case. The 3-in-1 case means that 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 that is open at at least one end, i.e., a front end, i.e., a front flange 212 that protrudes outward from the front end of the cylinder 211, a rear flange 213 that protrudes outward from the other end, i.e., a rear ... support frame 214 that is disposed on the inner periphery of the cylinder 211 so as to be positioned at the rear end of the cylinder 211. Here, the axial direction X refers to the axial direction X of the rotation shaft of a component that constitutes the unit 1. The component is, for example, a motor 3, a gear mechanism, a differential gear mechanism, etc.

[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, which will be described later; a first support wall 214b that is located closer to the front end of the cylinder 211 than the annular wall 214a and is arranged to support bearing B1; and a second support wall 214c as a second wall portion that is aligned with the annular wall 214a in the lateral direction Y, which is the first radial direction, and is arranged to support bearing B2, which is the first bearing.

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

[0017] The annular wall 214a, the first support wall 214b, and the second support wall 214c are integrally formed, which eliminates the need to individually form the components that make up the support frame 214, thereby preventing an increase in the number of components.

[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 bolts. The second case 22 also supports both bearings B3 and B4. The second case 22 rotatably supports both the front end of one end of the rotating shaft 31 of the motor 3 and the front end of one end of the drive shaft 6 (specifically, the first drive shaft 61 that constitutes the drive shaft 6) via the bearings B3 and B4, respectively.

[0019] The third case 23 is disposed on the inner circumferential 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. The third case 23 is also 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 bolts so as to be located in the region inside the first case 21.

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

[0021] The fourth case 24 houses the reduction gear group 5. The fourth case 24 is configured as a bottomed cylinder that is open at one end (front end) and closed at the other end (rear end). 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 bolts.

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

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

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

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

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

[0027] The inverter 4 is a controller for controlling the driving of the motor 3. The inverter 4 is accommodated in the inverter accommodating 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 operatively connected downstream of the motor 3 and operatively connected upstream of the drive shaft 6. The reduction gear group 5 is housed in a reduction gear group housing chamber S2 formed by the first case 21, third case 23, and fourth case 24 that are connected together.

[0029] 1 , the reduction gear group 5 has, arranged in this order from upstream to downstream, 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. Power from the motor 3 is transmitted to the drive shaft 6 via 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 this order.

[0030] Hereinafter, a second element (component, part, etc.) connected to a first element (component, part, etc.), a second element (component, part, etc.) connected downstream of a first element (component, part, etc.), or a second element (component, part, etc.) connected upstream of a first element (component, part, etc.) means that the first element and the second element are connected so that power can be transmitted. The power input side is upstream, and the power output side is downstream. They may also be connected via another mechanism (e.g., a clutch, another gear mechanism, etc.).

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

[0032] This allows 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, to be attached after the planetary gear mechanism 51 is attached to the annular wall 214a, resulting in a case structure that is easy to assemble.

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

[0034] In addition, when viewed in the radial direction, the planetary gear mechanism 51 overlaps with the inverter accommodating chamber S1. That is, the planetary gear mechanism 51 and the inverter accommodating chamber S1 are aligned in the vertical direction Z, which serves as a second radial direction perpendicular to the horizontal direction Y.

[0035] In other words, when viewed in the radial direction, the inverter accommodating chamber S1 has a portion that overlaps with the planetary gear mechanism 51. This creates space radially outward from the space in which the planetary gear mechanism 51 is disposed, and by forming the inverter accommodating chamber S1 in this space, the space can be used effectively, which can contribute to making the entire unit 1 more compact.

[0036] The planetary gear mechanism 51 has a sun gear 511, a carrier 512, and a ring gear 513. A group of pinion gears 514 that meshes with both the sun gear 511 and the ring gear 513 is disposed between the sun gear 511 and the ring gear 513. The ring gear 513 is fixed to the inner periphery of the annular wall 214a so as not to rotate. The group of pinion gears 514 is supported by the carrier 512 so as to be rotatable.

[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 axis of the rotating shaft 31 and the axis of the first shaft 7 both coincide with the axis C1 of the first shaft. By arranging the planetary gear mechanism 51 coaxially with the rotating shaft 31 of the motor 3 in this manner, a high gear ratio is achieved, and radial expansion of the unit 1 can be suppressed compared to 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 bearing B7 than to 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, planetary gear mechanism 51, and first gear 52 are arranged coaxially on the axis C1. By providing the planetary gear mechanism 51 coaxially between the first gear 52, which serves as the first-stage gear, and the motor 3, it is possible to prevent the unit 1 from expanding in the radial direction.

[0039] The second gear 53 meshes with the first gear 52. The second gear 53 has a larger number of teeth than the first gear 52 and constitutes a 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. In other words, the second gear 53 and the third gear 54 are arranged coaxially with the axis C2 of the second shaft 8 serving as the second shaft.

[0041] Furthermore, the third gear 54 is located 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. This makes it possible to suppress expansion of the unit 1 in the axial direction X and the radial directions Y and Z, compared to a configuration in which the second gear 53 is located between the planetary gear mechanism 51 and the third gear 54.

[0042] When viewed in the axial direction, 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 aligned in the axial direction X.

[0043] In other words, when viewed in the axial direction, the planetary gear mechanism 51 has a portion that overlaps with the second gear 53 and the third gear 54. This allows the space in the reduction gear group housing chamber S2 to be used effectively, which contributes to making the entire unit 1 more compact.

[0044] The fourth gear 55 meshes with the third gear 54. The fourth gear 55 has a larger number of teeth than the third gear 54 and constitutes a second reduction gear stage together with the third gear 54. 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. This allows the reduction gear diameter to be smaller to ensure a reduction ratio compared to one-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 a differential part 562. The differential case 561 is rotatably supported by the first case 21 and the fourth case 24 via bearings B2 and B9. The differential case 561 is also coupled to the inner periphery of the fourth gear 55 so as to rotate integrally with the fourth gear 55.

[0047] The differential portion 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. The drive shaft 6 also includes 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 axis C3, which serves as the third axis.

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

[0050] This creates space radially outside the space in which the planetary gear mechanism 51 is arranged, and by placing the differential gear 56 in this space, the space can be used effectively, which contributes to making the unit 1 smaller.

[0051] When viewed in the radial direction, the differential gear 56 overlaps with the third case 23. That is, the differential gear 56 and the third case 23 are aligned in the lateral direction Y.

[0052] In other words, when viewed in the radial direction, the differential gear 56 has a portion that overlaps 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 radially outward from the space in which the third case 23 is disposed, and by forming the differential gear 56 to pass through this opening (i.e., by arranging the differential gear 56 in both the area within the first case 21 and the area within the fourth case 24), the space created by this opening can be effectively utilized, which can contribute to a reduction in size of the unit 1 (particularly in the axial direction X) compared to a configuration in which the differential gear 56 is disposed only in the area within the fourth case 24.

[0053] By increasing the gear ratio of the entire reduction gear group 5 (because the gear ratio and the reduction ratio are inversely proportional, the reduction ratio becomes smaller), the maximum torque required for the motor 3 can be reduced, which contributes to the miniaturization of the motor 3. Furthermore, since the number of reductions is increased by adding the planetary gear mechanism 51 in order to increase the gear ratio, the differential diameter (proportional to the diameter of the fourth gear 55, which serves as a reduction gear that rotates integrally with the differential gear 56) can be reduced, making the layout easier.

[0054] (Operations and Effects) Next, the main operations and effects of this embodiment will be described.

[0055] (1) The unit 1 according to this embodiment includes a motor 3 (rotating electric machine), a planetary gear mechanism 51 connected downstream of the motor 3 (rotating 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 (rotating electric machine), the planetary gear mechanism 51, and the first gear 52 are arranged on an axis C1 (first axis), the second gear 53 and the third gear 54 are arranged on an 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 providing the planetary gear mechanism 51 coaxially between the first gear 52, which serves as a first-stage gear, and the motor 3, it is possible to suppress radial expansion of the unit 1. Furthermore, since the third gear 54 is sandwiched and disposed between the planetary gear mechanism 51 and the second gear 53, it is possible to suppress 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, and the fourth gear 55 and the differential gear 56 are arranged on the axis C3, and the differential gear 56 is arranged closer to the planetary gear mechanism 51 than the fourth gear 55.

[0058] According to this configuration, space is created radially outside the space in which the planetary gear mechanism 51 is arranged, and by placing the differential gear 56 in this space, the space can be used effectively, which contributes to making the unit 1 smaller.

[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 the bearing B2 (first bearing) on ​​which the differential gear 56 is supported, and the annular wall 214a (first wall portion) and the second support wall 214c (second wall portion) are integrally formed.

[0060] According to this configuration, the components that make up the support frame 214 do not need to be individually formed, and an increase in the number of components can be suppressed.

[0061] (4) The 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 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, resulting in a case structure that is easy to assemble.

[0063] (5) The unit 1 further includes the inverter 4. When viewed in the radial direction, the inverter accommodating chamber S1 that accommodates the inverter 4 has a portion that overlaps with the planetary gear mechanism 51.

[0064] According to this configuration, space is generated radially outside the space in which the planetary gear mechanism 51 is arranged, and by forming the inverter accommodating chamber S1 in this space, the space can be utilized effectively, thereby contributing to the miniaturization of the entire unit 1.

[0065] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above embodiments.

[0066] DESCRIPTION OF SYMBOLS 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 shaft) C2 Axis (second shaft) C3 Axis (third shaft) S1 Inverter accommodating chamber

Claims

1. A rotating electric machine; a planetary gear mechanism connected downstream of the rotating electric machine; A first gear connected downstream of the planetary gear mechanism; A second gear that meshes with the first gear; a third gear connected downstream of the second gear, the rotating electric machine, the planetary gear mechanism, and the first gear are disposed on a first shaft, the second gear and the third gear are disposed on a second shaft, the third gear has a portion that is sandwiched between a ring gear of the planetary gear mechanism and the second gear in the axial direction, The third gear has a portion overlapping with the ring gear when viewed in the axial direction. unit.

2. a fourth gear that meshes with the third gear; a differential gear connected downstream of the fourth gear; A drive shaft connected downstream of the differential gear, the fourth gear and the differential gear are disposed on a third shaft, The differential gear is disposed closer to the planetary gear mechanism than the fourth gear. The unit according to claim 1.

3. A first wall portion that fixes a ring gear of the planetary gear mechanism; A second wall portion supporting a first bearing on which the differential gear is supported, The first wall portion and the second wall portion are integrally formed. The unit according to claim 2.

4. A third wall portion facing the planetary gear mechanism is further provided. The third wall portion is formed separately from the first wall portion and the second wall portion, A second bearing supporting a first shaft that rotates integrally with the first gear and a third bearing supporting a second shaft that rotates integrally with the third gear are supported on the third wall portion. A unit as claimed in claim 3.

5. Further comprising an inverter; When viewed in the radial direction, an inverter accommodating chamber that accommodates the inverter has a portion that overlaps with the planetary gear mechanism. A unit according to any one of claims 1 to 4.