unit

Abstract

[Problem] To reduce the effects of looseness on a common member between planetary gear mechanisms. [Solution] This unit includes: a first planetary gear mechanism having a first sun gear, a first carrier, and a first ring gear; a second planetary gear mechanism having a second sun gear, a second carrier, and a second ring gear; and a shaft passing through the inner circumference of the first sun gear and the second sun gear. The first planetary gear mechanism and the second planetary gear mechanism have a common member having a configuration such that one of the first carrier and the first ring gear and one of the second carrier and the second ring gear rotate integrally. The common member is supported by the shaft, by means of a bearing, at a position between the first sun gear and the second sun gear.

Description

[Technical Field]

[0001] The present invention relates to a unit. [Background technology]

[0002] Patent Document 1 discloses a transmission in which one ring gear of two planetary gear mechanisms is connected to the other carrier. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Chinese Patent Application Publication No. 105443707 Summary of the Invention [Problem to be solved by the invention]

[0004] In a unit in which a specific element, such as a ring gear on one side and a carrier on the other side, rotates integrally as a common member between planetary gear mechanisms, the common member has a larger mass than each of its constituent elements. As a result, the common member is more likely to become eccentric and to run out more due to the influence of backlash in the gears, play in the splines, and other factors, which can easily cause vibration.

[0005] The present invention has been made in view of the above-mentioned problems, and has an object to reduce the influence of backlash on members common to planetary gear mechanisms. [Means for solving the problem]

[0006] A unit according to one aspect of the present invention includes a first planetary gear mechanism having a first sun gear, a first carrier, and a first ring gear, a second planetary gear mechanism having a second sun gear, a second carrier, and a second ring gear, and a shaft passing through the inner peripheries of the first sun gear and the second sun gear. The first planetary gear mechanism and the second planetary gear mechanism have a common member configured so that one of the first carrier and the first ring gear and one of the second carrier and the second ring gear rotate integrally. The common member is supported by the shaft via a bearing at a position between the first sun gear and the second sun gear. The shaft has a protrusion sandwiched between the first sun gear and the second sun gear in the axial direction, and the common member is supported by the protrusion via the bearing. . [Effects of the Invention]

[0007] According to this aspect, a common member is configured such that one of two elements (carrier, ring gear) located around the sun gear between the planetary gear mechanisms rotates integrally with the other (e.g., the first ring gear and the second carrier), and the common member is supported on the shaft via a bearing. That is, the common member is supported by providing support between the shaft and the common member in the radial direction, such as by extending the support radially from the shaft side to the inner diameter side of the common member. This suppresses rattle of the common member, thereby reducing the effect of rattle of the unit on the common member. Furthermore, placing a bearing between the first sun gear and the second sun gear means that the common member is supported via the bearing near the center of the common member, rather than at its end. Therefore, by supporting the common member via the bearing at a position that is well-balanced in the axial direction, rattle of the common member is suppressed, thereby further reducing the effect of rattle of the unit on the common member. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram of the unit according to this embodiment. [Figure 2] FIG. 2 is a skeleton diagram of the unit. [Figure 3] FIG. 3 is an enlarged view of the main part of the unit. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0010] Fig. 1 is a schematic diagram of a unit 100 according to this embodiment. Fig. 2 is a skeleton diagram of the unit 100. Fig. 3 is an enlarged view of the main part of the unit 100.

[0011] Regarding the term "unit," a unit can also be called, for example, 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 electric machine having an electric motor function and / or a generator function (at least one of an electric motor function and a generator function). A 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.

[0012] As shown in Fig. 1, the unit 100 includes a housing 10 and a transmission mechanism 20. The unit 100 is mounted on a vehicle, which is an electric vehicle. Power is input to the unit 100 from an MG 40. The MG 40 is a rotating electric machine that functions as a motor generator, and the unit 100 can also be understood as a configuration that further includes the MG 40.

[0013] The housing 10 accommodates the transmission mechanism 20. The transmission mechanism 20 includes a case 21, a rotating shaft 22, a first planetary gear mechanism PGM1, a second planetary gear mechanism PGM2, a first brake B1, a second brake B2, and a clutch CL. The case 21 is cylindrical and fixed to the inner periphery of the housing 10. The first planetary gear mechanism PGM1 is provided within the case 21 via the first brake B1, and the second planetary gear mechanism PGM2 is provided within the case 21 via the second brake B2. The rotating shaft 22 is connected to the MG4 and rotates by power from the MG40. The extending direction of the rotating shaft 22 corresponds to the axial direction of the unit 100, and this axial direction refers to the axial direction of the rotating shafts of the components that make up the unit (for example, a motor, a gear mechanism, or a differential gear mechanism).

[0014] The first planetary gear mechanism PGM1 includes a first sun gear S1, a first carrier C1, a first ring gear R1, and a first pinion gear P1. The first sun gear S1 is coaxially fixed to the rotary shaft 22. The first carrier C1 rotatably supports the first pinion gear P1. The first pinion gear P1 meshes with both the first sun gear S1 and the first ring gear R1. The same applies to the second planetary gear mechanism PGM2, which includes a second sun gear S2, a second carrier C2, a second ring gear R2, and a second pinion gear P2.

[0015] A rotation shaft 22 passes through the inner peripheries of the first sun gear S1 and the second sun gear S2, and the second planetary gear mechanism PGM2 is arranged axially alongside the first planetary gear mechanism PGM1. Therefore, the first planetary gear mechanism PGM1 has a portion that overlaps with the second planetary gear mechanism PGM2 when viewed in the axial direction. "Overlapping" when viewed in a predetermined direction, including radial and axial views, refers to overlapping in a predetermined direction, meaning that multiple elements are aligned in the predetermined direction. Therefore, when a drawing shows multiple elements aligned in a predetermined direction, it can be assumed that the specification contains a statement explaining that multiple elements overlap when viewed in the predetermined direction. The second planetary gear mechanism PGM2 is located on the side away from the MG40 relative to the first planetary gear mechanism PGM1. The rotation shaft 22 corresponds to a shaft.

[0016] In the first planetary gear mechanism PGM1 and the second planetary gear mechanism PGM2, the first ring gear R1 and the second carrier C2 constitute a common member CM that rotates integrally. In other words, the first planetary gear mechanism PGM1 and the second planetary gear mechanism PGM2 have a common member CM in which the first ring gear R1 and the second carrier C2 rotate integrally. In the common member CM, the first ring gear R1 and the second carrier C2, which are components of the common member CM, always rotate integrally during rotation. The first ring gear R1 and the second carrier C2 are integrally formed and connected to each other to form the common member CM. The second carrier C2 constitutes the output element of the second planetary gear mechanism PGM2. In contrast, the first carrier C1 constitutes the output element of the first planetary gear mechanism PGM1 and also constitutes the output element of the entire first planetary gear mechanism PGM1 and the entire second planetary gear mechanism PGM2, thereby constituting the output element of the entire transmission mechanism 20.

[0017] The first brake B1 is provided on the outer periphery of the first ring gear R1 and is connected to the first planetary gear mechanism PGM1. The second brake B2 is provided on the outer periphery of the second ring gear R2 and is connected to the second planetary gear mechanism PGM2. Therefore, the first brake B1 has a portion that overlaps with the first planetary gear mechanism PGM1 when viewed in the radial direction, and the second brake B2 has a portion that overlaps with the second planetary gear mechanism PGM2 when viewed in the radial direction.

[0018] The first brake B1 and the second brake B2 are both meshing engagement elements and have a meshing fastening structure. When the first brake B1 is engaged, the first ring gear R1 is fixed to the case 21 together with the second carrier C2. As a result, the first ring gear R1 is fixed to the housing 10 together with the second carrier C2. In other words, the common member CM is fixed to the housing 10. When the second brake B2 is engaged, the second ring gear R2 is fixed to the case 21. As a result, the second ring gear R2 is fixed to the housing 10.

[0019] The clutch CL is arranged axially alongside the second planetary gear mechanism PGM2 from the side away from the MG40. The clutch CL is provided for the rotary shaft 22 and the second carrier C2, and connects and disconnects them. The clutch CL is a friction engagement element and is a multi-plate clutch. The clutch CL is, for example, an electric clutch, and includes a hub 23, a drum 24, a plurality of drive plates 25, a plurality of driven plates 26, and a piston 27.

[0020] The hub 23 is fixed coaxially to the rotary shaft 22. The hub 23 has an inner cylindrical portion 23a, an outer cylindrical portion 23b, and a bottom wall portion 23c connecting these, and is fixed coaxially to the rotary shaft 22 at the inner cylindrical portion 23a. The drum 24 has a cylindrical portion 24a and a bottom wall portion 24b, and is provided coaxially with the rotary shaft 22. The drum 24 opens in a direction away from the MG 40. The hub 23 is housed within the drum 24, and the outer periphery of the outer cylindrical portion 23b of the hub 23 faces the inner periphery of the cylindrical portion 24a of the drum 24. The drum 24 is fixedly connected to the second carrier C2 at the ring-plate-shaped bottom wall portion 24b.

[0021] A plurality of drive plates 25 are provided on the hub 23. The plurality of drive plates 25 are ring-shaped and are provided on the outer periphery of the outer cylindrical portion 23b so as to be slidable in the axial direction. A plurality of driven plates 26 are provided on the drum 24. The plurality of driven plates 26 are ring-shaped and are provided on the inner periphery of the cylindrical portion 24a so as to be slidable in the axial direction. The plurality of drive plates 25 and the plurality of driven plates 26 are provided alternately arranged one by one in the axial direction.

[0022] The piston 27 is provided inside the drum 24. The piston 27 is slidably provided on the inner periphery of the open end of the drum 24. The piston 27 is, for example, an electric piston driven by an electric actuator of the clutch CL, and moves in the engagement direction (leftward in FIG. 1) and disengagement direction (rightward in FIG. 1) of the clutch CL to engage and disengage the plurality of drive plates 25 and the plurality of driven plates 26.

[0023] When the plurality of drive plates 25 and the plurality of driven plates 26 are pushed in the engagement direction by the piston 27 and engage, the clutch CL enters an engaged state. As a result, the rotating shaft 22 and the second carrier C2 are connected via the clutch CL. Furthermore, when the piston 27 moves from this state in the disengagement direction and the plurality of drive plates 25 and the plurality of driven plates 26 are no longer engaged, the clutch CL enters a disengaged state. As a result, the connection between the rotating shaft 22 and the second carrier C2 via the clutch CL is cut off.

[0024] The unit 100 further includes a drive device 30. The drive device 30 is a drive device for the first brake B1 and the second brake B2, and includes an actuator 31 and a worm wheel 32. In Fig. 1, the actuator 31 is schematically indicated by a two-dot dashed line.

[0025] The actuator 31 is an electric motor and has a worm gear 311. The worm gear 311 forms the rotation axis of the actuator 31 and meshes with the worm wheel 32. The worm axis of the worm gear 311 and the central axis of the worm wheel 32 are perpendicular to each other, and the worm wheel 32 is provided so as to be rotatable around the axis of the unit 100 by power from the actuator 31. Therefore, the longitudinal direction of the worm gear 311, which is the worm axis direction, intersects with the axial direction of the unit 100. The worm gear 311 and the worm wheel 32 are provided between the first brake B1 and the second brake B2 in the axial direction of the unit 100, and have a portion sandwiched between the first brake B1 and the second brake B2.

[0026] The first brake B1 is provided with a first switching mechanism SWM1, and the second brake B2 is provided with a second switching mechanism SWM2. Both the first switching mechanism SWM1 and the second switching mechanism SWM2 have a ring-shaped appearance. The first switching mechanism SWM1 has a portion that overlaps with the first brake B1 in the axial direction. Similarly, the second switching mechanism SWM2 is provided with the second brake B2 and has a portion that overlaps with the second brake B2 in the axial direction. The first switching mechanism SWM1 switches the engagement state of the first brake B1, and the second switching mechanism SWM2 switches the engagement state of the second brake B2. The first switching mechanism SWM1 switches the engagement state of the first brake B1 between a bidirectional restriction state that restricts bidirectional rotation of the first ring gear R1, a unidirectional restriction state that restricts unidirectional rotation, and a release state that does not restrict rotation. The same applies to the second switching mechanism SWM2.

[0027] The actuator 31 activates the first brake B1 by driving the first switching mechanism SWM1 via the worm gear 311 and the worm wheel 32. Similarly, the actuator 31 activates the second brake B2 by driving the second switching mechanism SWM2 via the worm gear 311 and the worm wheel 32. The first brake B1 and the second brake B2 correspond to engagement elements, and the first switching mechanism SWM1 and the second switching mechanism SWM2 both correspond to operating mechanisms.

[0028] The unit 100 further includes a bearing 40 and an extension member 41. The bearing 40 is a radial needle bearing and abuts against the rotating shaft 22 on the inner peripheral side. The bearing 40 is not limited to a bearing and may be, for example, a bushing. The bearing 40 is provided between the common member CM and the rotating shaft 22 in the radial direction. The bearing 40 is disposed at an axial position where it radially overlaps with the first switching mechanism SWM1 and the second switching mechanism SWM2. In other words, the first switching mechanism SWM1 and the second switching mechanism SWM2 have portions that radially overlap with the bearing 40.

[0029] As described above, the first switching mechanism SWM1 has a portion that overlaps with the first brake B1 in the axial direction, and the second switching mechanism SWM2 has a portion that overlaps with the second brake B2 in the axial direction. Therefore, the first switching mechanism SWM1 and the second switching mechanism SWM2, which are arranged to have portions that overlap with the bearing 40 in the radial direction, are arranged in a surplus space formed axially adjacent to the first brake B1 and the second brake B2. As a result, the surplus space can be used to provide the first switching mechanism SWM1 and the second switching mechanism SWM2, thereby realizing a layout of the unit 100 that contributes to reducing the axial dimension.

[0030] The common member CM is supported by the rotating shaft 22 via a bearing 40 at a position (axial position) between the first sun gear S1 and the second sun gear S2. This suppresses rattle of the common member CM, thereby reducing the influence of backlash of the unit 100, such as gear backlash and spline rattle, on the common member CM. Furthermore, by disposing the bearing 40 between the first sun gear S1 and the second sun gear S2, the common member CM is supported via the bearing 40 at a position that is well-balanced in the axial direction, thereby suitably suppressing rattle of the common member CM. As a result, the influence of backlash of the unit 100 on the common member CM is further reduced. The common member CM is supported on the rotating shaft 22 via the bearing 40, and further via an extension member 41.

[0031] The extension member 41 has a cylindrical shape and is interposed radially between the bearing 40 and the common member CM. The inner peripheral side of the extension member 41 abuts against the bearing 40, and the outer peripheral side is attached to the common member CM. As shown in FIG. 3, the extension member 41 has an extension portion 41a. The extension portion 41a is provided on the extension member 41 at a portion on the axial side of the second gear mechanism PGM2 and has a flange-like shape. A radial gap formed between the extension member 41 and the common member CM at a portion on the axial side of the extension portion 41a that is closer to the first gear mechanism PGM1 than the extension portion 41a is used as an oil passage.

[0032] The extension member 41 extends support radially from the rotating shaft 22 side to the inner diameter side of the common member CM. The extension portion 41a is fitted into the spigot portion E of the common member CM, thereby supporting the common member CM on the rotating shaft 22 via the bearing 40 and the extension member 41. Other shapes may be applied to the extension member 41, and the extension member 41 may be formed integrally with the common member CM. On the other hand, by providing the extension member 41, support is extended radially from the rotating shaft 22 side to the inner diameter side of the common member CM, making it possible to support the common member CM on the rotating shaft 22 via the bearing 40 without modifying the common member CM. In addition, by partially extending the extension member 41 further in the radial direction using the extension portion 41a, it is also possible to ensure an oil passage.

[0033] The rotary shaft 22 has a protrusion 22a. The protrusion 22a is a portion that protrudes in the radial direction and is formed as an enlarged diameter portion that protrudes around the entire circumference. For example, a plurality of protrusions 22a may be provided partially in the circumferential direction. The protrusion 22a is disposed between the first sun gear S1 and the second sun gear S2 in the axial direction. Therefore, the rotary shaft 22 has the protrusion 22a that is sandwiched between the first sun gear S1 and the second sun gear S2 in the axial direction.

[0034] Protrusion 22a regulates the axial positions of first sun gear S1 and second sun gear S2 at stepped portions at both axial ends, thereby restricting axial displacement of first sun gear S1 toward second sun gear S2 and axial displacement of second sun gear S2 toward first sun gear S1.

[0035] The bearing 40 is disposed on the protrusion 22a, and the common member CM is supported on the protrusion 22a via the bearing 40. The protrusion 22a increases the rigidity of the rotating shaft 22. Therefore, by disposing the bearing 40 on the protrusion 22a, the influence on the deflection of the rotating shaft 22 caused by supporting the common member CM on the rotating shaft 22 via the bearing 40 is reduced.

[0036] Next, the main effects of this embodiment will be described.

[0037] (1) Unit 100 includes a first planetary gear mechanism PGM1 having a first sun gear S1, a first carrier C1, and a first ring gear R1; a second planetary gear mechanism PGM2 having a second sun gear S2, a second carrier C2, and a second ring gear R2; and a rotating shaft 22 passing through the inner peripheries of the first sun gear S1 and the second sun gear S2. The first planetary gear mechanism PGM1 and the second planetary gear mechanism PGM2 include a common member CM configured such that the first ring gear R1, which is one of the first carrier C1 and the first ring gear R1, and the second carrier C2, which is one of the second carrier C2 and the second ring gear R2, rotate integrally. The common member CM is supported on rotating shaft 22 via bearings 40 at a position between the first sun gear S1 and the second sun gear S2.

[0038] According to this configuration, the common member CM is supported on the rotating shaft 22 via the bearing 40. In other words, the common member CM is supported by providing support between the rotating shaft 22 and the common member CM in the radial direction, for example by extending the support radially from the rotating shaft 22 side to the inner diameter side of the common member CM. This makes it possible to suppress rattle of the common member CM, thereby reducing the effect of rattle of the unit 100 on the common member CM. Furthermore, by arranging the bearing 40 between the first sun gear S1 and the second sun gear S2, the common member CM can be supported via the bearing 40 at a position that is well-balanced in the axial direction, thereby suitably suppressing rattle of the common member CM, thereby further reducing the effect of rattle of the unit 100 on the common member CM.

[0039] (2) The rotary shaft 22 has a protrusion 22a sandwiched between the first sun gear S1 and the second sun gear S2 in the axial direction. The common member CM is supported by the protrusion 22a via a bearing 40.

[0040] With this configuration, the protrusions 22a can suppress axial misalignment of the first sun gear S1 and the second sun gear S2. Furthermore, because the common member CM is supported via the bearings 40 by the protrusions 22a, which increase the rigidity of the rotating shaft 22, the effect on deflection of the rotating shaft 22 caused by supporting the common member CM on the rotating shaft 22 via the bearings 40 can be reduced.

[0041] (3) The unit 100 further includes a first brake B1 connected to the first planetary gear mechanism PGM1, a second brake B2 connected to the second planetary gear mechanism PGM2, and a first switching mechanism SWM1 and a second switching mechanism SWM2 that operate the first brake B1 and the second brake B2. The first switching mechanism SWM1 and the second switching mechanism SWM2 have portions that radially overlap with the bearing 40.

[0042] With this configuration, the first switching mechanism SWM1 and the second switching mechanism SWM2 can be provided by utilizing the extra space formed axially adjacent to the first brake B1 and the second brake B2, thereby realizing a layout of the unit 100 that contributes to reducing the axial dimension.

[0043] 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.

[0044] For example, in the above-described embodiment, the first ring gear R1 and the second carrier C2 are the common member CM. However, the common member CM may be the first carrier C1 and the second ring gear R2, the first carrier C1 and the second carrier C2, or the first ring gear R1 and the second ring gear R2.

[0045] The unit 100 may have either the first brake B1 or the second brake B2 as an engagement element. Even in this case, the first switching mechanism SWM1 or the second switching mechanism SWM2 can be provided using the extra space formed axially adjacent to either the first brake B1 or the second brake B2, thereby realizing a layout of the unit 100 that contributes to reducing the axial dimension. [Explanation of symbols]

[0046] 10. Housing 20 Transmission mechanism 22 Rotating shaft 22a Protrusion 40 Bearings 100 units B1 First brake (engaging element) B2 Second brake (engagement element) C1 First Carrier C2 Second Carrier CM common parts PGM1 First planetary gear mechanism PGM2 2nd planetary gear mechanism R1 1st ring gear R2 Second ring gear S1 1st sun gear S2 Second sun gear SWM1 First switching mechanism (operating mechanism) SWM2 Second switching mechanism (operating mechanism)

Claims

1. a first planetary gear mechanism having a first sun gear, a first carrier, and a first ring gear; a second planetary gear mechanism having a second sun gear, a second carrier, and a second ring gear; a shaft passing through inner peripheries of the first sun gear and the second sun gear; and the first planetary gear mechanism and the second planetary gear mechanism have a common member in which one of the first carrier and the first ring gear and one of the second carrier and the second ring gear rotate integrally, the common member is supported on the shaft via a bearing at a position between the first sun gear and the second sun gear; the shaft has a protrusion sandwiched between the first sun gear and the second sun gear in the axial direction, the common member is supported by the protrusion via the bearing; unit.

2. 2. The unit of claim 1, an engaging element connected to at least one of the first planetary gear mechanism and the second planetary gear mechanism; an actuation mechanism for actuating the engagement element; and the actuation mechanism has a portion that radially overlaps with the bearing; unit.

3. A first planetary gear mechanism having a first sun gear, a first carrier, and a first ring gear; a second planetary gear mechanism having a second sun gear, a second carrier, and a second ring gear; a shaft passing through inner peripheries of the first sun gear and the second sun gear; an engaging element connected to at least one of the first planetary gear mechanism and the second planetary gear mechanism; an actuation mechanism for actuating the engagement element; and the first planetary gear mechanism and the second planetary gear mechanism have a common member in which one of the first carrier and the first ring gear and one of the second carrier and the second ring gear rotate integrally, the common member is supported on the shaft via a bearing at a position between the first sun gear and the second sun gear; the actuation mechanism has a portion that radially overlaps with the bearing; unit.

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