Torque transmission device

Abstract

A torque transmission device (10) for transmitting torque between a first member (11) and a second member (12) comprises: a differential gear mechanism (7) configured such that a first rotary element (E1), a second rotary element (E2), and a third rotary element (E3) are arranged in the order of rotational speed; a first input member (1) fixed to the first member (11) and the first rotary element (E1); a second input member (2) fixed to the second member (12) and the third rotary element (E3); a reaction force support member (3) supported by a support member that is provided separately from a torque transmission path, and fixed to the second rotary element (E2); and a differential limiting mechanism (5) for limiting the differential between the first input member (1) and the second input member (2), and also for changing the limitation state of the differential.

Description

Torque Transmission Device

[0001] The present invention relates to a torque transmission device that transmits torque between a first member and a second member.

[0002] As an example of a device using such a torque transmission device, Japanese Patent Application Laid-Open Publication No. 2007-162758 discloses a stabilizer mounted on a vehicle. This stabilizer is configured with a cylindrical housing (10), a first stabilizer bar (14), a second stabilizer bar (15), a motor (20), and a reduction gear (G) arranged coaxially (reference numerals in parentheses in the Background Art section refer to those in the referenced documents). The rotation of the output shaft (23) of the motor (20) is reduced by the reduction gear (G), causing the first stabilizer bar (14) to rotate relative to the housing (10). In this stabilizer, the torque of the motor (20) is amplified by the reduction gear (G) and converted into torsional torque in the stabilizer, thereby changing the rigidity of the vehicle body against forces that tilt the vehicle left and right (roll).

[0003] Japanese Patent Application Laid-Open No. 2007-162758

[0004] In the case of torque transmission devices with the above-described structure, there is a tendency for the motor to become larger and the reduction ratio of the reduction mechanism to become higher in order to obtain the torque required to change the rigidity of the vehicle body, i.e., the torque transmission mechanism tends to become larger in size in order to appropriately change the torque transmitted in the torque transmission device.

[0005] Therefore, it is desirable to realize a torque transmission mechanism that can appropriately change the transmitted torque while preventing the mechanism from becoming large.

[0006] In view of the above, a torque transmission device is a torque transmission device that transmits torque between a first member and a second member, and includes a differential gear mechanism that includes a first rotating element, a second rotating element, and a third rotating element, and is configured so that the rotational speeds of the first rotating element, the second rotating element, and the third rotating element are in the order described above; a first input member that is fixed to the first member and fixed to the first rotating element; a second input member that is fixed to the second member and fixed to the third rotating element; a reaction force support member that is supported by a support member provided separately from the torque transmission path and fixed to the second rotating element; and a differential limiting mechanism that limits the differential between the first input member and the second input member and is capable of changing the limited state of the differential.

[0007] According to this configuration, by disposing the first member and the second member via a differential gear mechanism and limiting the differential movement of the differential gear mechanism with a differential limiting mechanism, the rigidity of the torque transmission structure between the first member and the second member can be changed. Specifically, limiting the differential movement with the differential limiting mechanism increases the rigidity of the torque transmission structure, while not limiting the differential movement with the differential limiting mechanism decreases the rigidity of the torque transmission structure. When the differential movement is not limited at all, in the case of an out-of-phase input, in which the input to the first input member and the input to the second input member are in opposite directions, the first input member and the second input member freely rotate relative to each other, resulting in the lowest rigidity of the torque transmission structure. When the input to the first input member and the input to the second input member are in the same direction, the first input member and the second input member are less likely to rotate relative to each other, resulting in high rigidity. Furthermore, when the differential limiting mechanism completely limits the differential movement, the first input member and the second input member cannot rotate relative to each other, resulting in the highest rigidity of the torque transmission structure, regardless of whether the input is an out-of-phase input or an in-phase input. In this way, with this configuration, it is possible to realize a torque transmission mechanism that can appropriately change the transmitted torque while preventing the mechanism from becoming large.

[0008] Further features and advantages of the torque transmission device will become apparent from the following description of exemplary, non-limiting embodiments thereof, which are given with reference to the drawings.

[0009] Schematic axial cross-sectional view of the torque transmission device of the first example Schematic orthogonal cross-sectional view of the torque transmission device of the first example Velocity diagram of the torque transmission device Schematic axial cross-sectional view of the torque transmission device of the second example Schematic explanatory top view showing an example of mounting the torque transmission device to a vehicle Schematic explanatory side view showing an example of mounting the torque transmission device to a vehicle Schematic explanatory top view showing another example of mounting the torque transmission device to a vehicle Schematic explanatory side view showing another example of mounting the torque transmission device to a vehicle

[0010] Hereinafter, embodiments of a torque transmission device will be described with reference to the drawings. Fig. 1 is a schematic axial cross-sectional view showing a first example of a torque transmission device 10. Fig. 2 is a schematic orthogonal cross-sectional view showing the first example of the torque transmission device 10. Fig. 1 is a cross-sectional view taken along line I-I in Fig. 2, and Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. As will be described later with reference to Figs. 5 to 8, the torque transmission device 10 is used in, for example, a stabilizer device or suspension device in a vehicle, and is connected to members (a first member 11, a second member 12) that transmit torque in the stabilizer device or suspension device.

[0011] As shown in FIG. 1 , the torque transmission device 10 transmits torque between a first member 11 and a second member 12. When the torque transmission device 10 is used in a vehicle, the first member 11 and the second member 12 are vehicle-side members. The torque transmission device 10 includes a first input member 1 fixed to the first member 11, a second input member 2 fixed to the second member 12, a reaction force support member 3, a differential gear mechanism 7, and a differential limiting mechanism 5. The first input member 1, the second input member 2, the reaction force support member 3, the differential gear mechanism 7, and the differential limiting mechanism 5 are arranged coaxially (on a transmission axis X1). Hereinafter, the direction along the transmission axis X1 will be referred to as the axial direction L. The reaction force support member 3 is supported by a support member provided separately from the torque transmission path of the torque transmission device 10. When the torque transmission device 10 is used in a vehicle, the support member is a vehicle body 300 (see FIGS. 6 to 8 , etc.). The support member is not limited to a non-rotating member such as the vehicle body 300, but may also be a rotating member (for example, a power transmission shaft) that rotates at the same rotational speed as the first member 11 and the second member 12.

[0012] The differential gear mechanism 7 includes a first rotating element E1, a second rotating element E2, and a third rotating element E3. FIG. 3 shows a speed diagram of the differential gear mechanism 7. As shown in FIG. 3, the differential gear mechanism 7 is configured so that the rotational speeds of the rotating elements are in the order of the first rotating element E1, the second rotating element E2, and the third rotating element E3. The first rotating element E1 is connected to the first input member 1, the second rotating element E2 is connected to the reaction force support member 3, and the third rotating element E3 is connected to the second input member 2. That is, the first input member 1 is fixed to the first member 11 and also to the first rotating element E1. The second input member 2 is fixed to the second member 12 and also to the third rotating element E3. The reaction force support member 3 is supported by a support member provided separately from the torque transmission path and is fixed to the second rotating element E2. Here, "fixed" includes not only separate members being integrally formed by welding, fastening, etc., but also a form in which the same member is integrally formed.

[0013] 1 and 2, the planetary gear mechanism of the torque transmission device 10 of the first example is a double-pinion type, and a carrier CA rotatably supports a first pinion gear PG1 and a second pinion gear PG2. As shown in Fig. 2, the first pinion gear PG1 meshes with a sun gear SG and a second pinion gear PG2, and the second pinion gear PG2 meshes with the first pinion gear PG1 and a ring gear RG. As shown in Figs. 1 and 3, in the torque transmission device 10 of the first example, the first rotating element E1 is the sun gear SG, the second rotating element E2 is the ring gear RG, and the third rotating element E3 is the carrier CA.

[0014] When rotational forces in different directions are input to the first input member 1 and the second input member 2, so-called reverse phase input occurs, as shown in FIG. 3 , the first input member 1 and the second input member 2 rotate relative to each other in opposite directions. That is, the first rotating element E1 (sun gear SG) and the third rotating element E3 (carrier CA) rotate relative to each other in opposite directions, with the second rotating element E2 (ring gear RG) as the fulcrum. That is, the first input member 1 and the second input member 2 are free to rotate relative to each other, and the rigidity of the torque transmission structure is at its lowest. When rotational forces in the same direction are input to the first input member 1 and the second input member 2, so-called in-phase input occurs, the first input member 1 and the second input member 2 do not rotate or rotate in the same direction (as will be described later with respect to the movable mechanism 30, in this embodiment, the second rotating element E2 is rotatable within a range in which it rotates relative to the housing 4).

[0015] The differential limiting mechanism 5 is configured to limit the differential between the first input member 1 and the second input member 2, and to be able to change the state of limiting the differential between the first input member 1 and the second input member 2. In this embodiment, the differential limiting mechanism 5 includes an engagement device 50 that engages the first input member 1 and the second input member 2. In this embodiment, the engagement device 50 is configured to include at least a pair of friction engagement members 53. The pair of friction engagement members 53 includes a first friction engagement member 51 and a second friction engagement member 52. As shown in FIG. 1 (as well as FIG. 4 ), in this embodiment, the engagement device 50 is configured to include a plurality of first friction engagement members 51 and a plurality of second friction engagement members 52, and a plurality of pairs of friction engagement members 53.

[0016] As described above, the limited slip differential mechanism 5 is disposed on the transmission shaft X1. The opposing direction, in which the friction engagement members (first friction engagement member 51, second friction engagement member 52) face each other, is the axial direction L. The engagement device 50 includes a pressing member 54 that presses the first friction engagement member 51 and the second friction engagement member 52 along the opposing direction, that is, the axial direction L, and a drive device that drives the pressing member 54 in the opposing direction. In this embodiment, the drive device that drives the engagement device 50 is exemplified by a drive motor 60 that is an electric actuator. In this embodiment, the pressing member 54 is connected to the drive motor 60 via a speed reduction mechanism 65 that reduces the rotation of the drive motor 60 and a rotation-to-linear motion conversion mechanism 66 that converts the rotation of the drive motor 60 into linear motion along the opposing direction. The electric actuator is not limited to this configuration, and the pressing member 54 may be connected to a movable iron core (plunger) of the solenoid.

[0017] Furthermore, the drive device that drives the pressing member 54 in the opposing direction is not limited to an electric actuator, but may be a hydraulic circuit and a pump that generates hydraulic pressure in the hydraulic circuit. Also, although a friction engagement device is exemplified as the engagement device 50 here, a meshing engagement device may also be used. Even when the engagement device 50 is a meshing engagement device, the drive device may be either electric or hydraulic.

[0018] The differential limiting mechanism 5 of this embodiment, which is equipped with a friction engagement device, is capable of changing whether or not to limit the differential between the first input member 1 and the second input member 2, and is also capable of changing the degree of limitation (limited state) when limiting the differential. Limiting the differential increases the rigidity of the torque transmission structure. When the differential between the first input member 1 and the second input member 2 is completely limited, the first input member 1 and the second input member 2 are connected so as to rotate integrally. When the differential limiting mechanism 5 completely limits the differential, the first input member 1 and the second input member 2 cannot rotate relative to each other, regardless of whether the input is in-phase or out-of-phase, and the rigidity of the torque transmission structure is maximized.

[0019] 1 , the first input member 1 is a shaft-shaped member with at least a portion in the axial direction L disposed on a first axial side L1, which is one side in the axial direction L, relative to the second input member 2. The second input member 2 is a hook-shaped cylindrical member with at least a portion in the axial direction L disposed on a second axial side L2, which is the opposite side in the axial direction L from the first axial side L1, relative to the first input member 1, and the first input member 1 penetrates the second input member 2 radially inward. Therefore, the first input member 1 and the second input member 2 at least partially overlap when viewed in the radial direction.

[0020] The second member 12 includes a small-diameter cylindrical portion 25 on the first axial side L1 and a large-diameter cylindrical portion 22 on the second axial side L2. A connecting member 21 for fixing the second input member 2 to the second member 12 is connected to the second axial side L2 of the large-diameter cylindrical portion 22. The connecting member 21 includes a bottom portion 21b that closes the opening of the large-diameter cylindrical portion 22 on the second axial side L2, and a shaft-shaped engaging portion 21a that protrudes from the bottom portion 21b toward the second axial side L2. The second input member 2 is fixed to the second member 12 by connecting the engaging portion 21a to the second member 12.

[0021] The large-diameter cylindrical portion 22 is provided on the first axial side L1 with a side wall portion 23 extending radially inward to close the opening of the large-diameter cylindrical portion 22 on the first axial side L1, and a cylindrical connecting portion 24 protruding from the side wall portion 23 toward the first axial side L1. The side wall portion 23 is formed to cover the radially outer region of the opening of the large-diameter cylindrical portion 22 on the first axial side L1, with the radially inner region remaining open. The cylindrical connecting portion 24 is formed to protrude from the radially inner end of the side wall portion 23 toward the first axial side L1. The radially inner side of the connecting portion 24 engages with the radially outer side of the small-diameter cylindrical portion 25, thereby connecting the large-diameter cylindrical portion 22 and the small-diameter cylindrical portion 25.

[0022] The first input member 1, which is a shaft-shaped member, is fixed to the first member 11 by being connected to the first member 11 at the first axial side L1. As described above, the first input member 1 is fixed to the sun gear SG of the planetary gear mechanism. However, in this embodiment, the sun gear SG is formed integrally with the first input member 1 using the same member as the first input member 1. Of course, the sun gear SG may be formed as a separate member from the first input member 1 and integrated with the first input member 1 by welding or fastening. As shown in FIG. 1 , the first input member 1 is disposed radially inside the cylindrical second input member 2, and the first input member 1 and the second input member 2 are disposed coaxially on the transmission shaft X1. Furthermore, an inner arrangement portion 15, which is disposed in an internal space radially inside the large-diameter cylindrical portion 22 of the second input member 2, is connected to the end of the shaft-shaped portion of the first input member 1 on the second axial side L2. The inner disposed portion 15 is formed in a hook shape (an angular C-shape) with an opening facing the second axial side L2.

[0023] A first friction engagement member 51 of the engagement device 50 is disposed radially inside the inner disposed portion 15. The first friction engagement member 51 is fixed to the inner disposed portion 15, and thereby the first friction engagement member 51 is fixed to the first input member 1. The inner disposed portion 15 can also be referred to as a first friction member support member. The second friction engagement member 52 is fixed to and supported by a second friction member support member 59. The second friction member support member 59 is fixed to the inner wall of the large-diameter cylindrical portion 22, and thereby fixed to the second input member 2. As a result, the second friction engagement member 52 is fixed to the second input member 2. The engagement device 50, which engages the first friction engagement member 51 and the second friction engagement member 52, can connect the first input member 1 and the second input member 2 by engaging the large-diameter cylindrical portion 22 with the inner disposed portion 15.

[0024] That is, in the torque transmission device 10, the second input member 2 includes a cylindrical portion (large diameter cylindrical portion 22) formed in a cylindrical shape, the first input member 1 includes an inner-arrangement portion 15 that is arranged in the internal space of the cylindrical portion (large diameter cylindrical portion 22) on a transmission axis X1 that is coaxial with the cylindrical portion (large diameter cylindrical portion 22), and the differential limiting mechanism 5 includes an engagement device 50 that is arranged in the internal space of the cylindrical portion (large diameter cylindrical portion 22) on the transmission axis X1 that is coaxial with the cylindrical portion (large diameter cylindrical portion 22) and engages the cylindrical portion (large diameter cylindrical portion 22) and the inner-arrangement portion 15.

[0025] As described above, the reaction force support member 3 fixed to the second rotating element E2 is supported by a support member (such as the vehicle body 300) that is provided separately from the torque transmission path of the torque transmission device 10. In this embodiment, the reaction force support member 3 is supported by the support member via a movable mechanism 30 that allows relative rotation between the support member (such as the vehicle body 300) and the reaction force support member 3. As shown in FIG. 1 , the movable mechanism 30 is provided between the reaction force support member 3 and the housing 4, which is a fixed support member fixed to the support member. In the torque transmission device 10, the movable mechanism 30 is provided between the housing 4 (fixed support member) and the reaction force support member 3, and is a mechanism that allows relative rotation between the housing 4 and the reaction force support member 3.

[0026] The movable mechanism 30 allows relative rotation between the housing 4 and the reaction force support member 3, thereby changing the relative phase between the housing 4 and the ring gear RG (second rotating element E2) fixed to the reaction force support member 3. That is, the fulcrum changes as shown by the hollow arrow in the velocity diagram of FIG.

[0027] The movable mechanism 30 includes a movable support mechanism 34 that supports the reaction force support member 3 so that the housing 4 and the reaction force support member 3 are rotatable relative to each other, and a biasing mechanism 36 that biases the housing 4 and the reaction force support member 3 so that the phase of the relative rotation between them becomes a predetermined reference phase. The differential gear mechanism 7, the movable mechanism 30, and the limited slip differential mechanism 5 are arranged coaxially with the rotation axis (transmission axis X1) of the first rotating element E1. That is, in this embodiment, the first input member 1, the second input member 2, the differential gear mechanism 7, the movable mechanism 30, and the limited slip differential mechanism 5 are arranged coaxially.

[0028] The movable support mechanism 34 includes a helical spline 31 formed on the reaction force support member 3, a linear spline 33 formed on the housing 4 (fixed support member) along the axial direction L, and a movable member 32. The movable member 32 engages with both the helical spline 31 and the linear spline 33 to drively connect the housing 4 and the reaction force support member 3. That is, the movable support mechanism 34 includes the movable member 32 that is movable in the axial direction L along the transmission axis X1, which is the rotation axis of the reaction force support member 3. The movable support mechanism 34 functions as a rotation-linear motion conversion mechanism that converts the movement direction between rotation of the movable member 32 guided by the helical spline 31 and linear motion of the movable member 32 guided by the linear spline 33. That is, the movable support mechanism 34 converts the relative rotation between the housing 4 (fixed support member) and the reaction force support member 3 into movement of the movable member 32 in the axial direction L.

[0029] The biasing mechanism 36 also includes a biasing spring 35 that biases the movable member 32 in the axial direction L. In this embodiment, the biasing spring 35 is a compression coil spring, but it may also be a tension coil spring. In this embodiment, the reference phase is the phase of relative rotation between the housing 4 and the reaction force support member 3 when the movable member 32 is most biased toward the first axial side L1 by the compression spring. That is, in this embodiment, the reference phase is a phase corresponding to one end (here, the end on the first axial side L1) of the range of movement of the movable member 32 caused by the rotary-to-linear motion conversion mechanism. However, this does not preclude the reference phase from being the middle of the range of movement of the movable member 32 instead of the end. For example, if the biasing spring 35 is a torsion coil spring that biases the reaction force support member 3 in the rotational direction, the middle of the range of movement of the movable member 32 may also be the reference phase.

[0030] Here, the movable support mechanism 34 is exemplified as a rotary-linear conversion mechanism including a helical spline 31 formed on the reaction force support member 3, a linear spline 33 formed on the housing 4, and a movable member 32. However, the present invention is not limited to this configuration, and may be configured such that the reaction force support member 3 is rotatably supported relative to the housing 4 by a bearing or the like.

[0031] Next, a second example of the torque transmission device 10 will be described with reference to Fig. 4. Descriptions of the same configuration as the first example and points that can be easily inferred from the above description of the first example will be omitted as appropriate.

[0032] As shown in FIG. 4 , the torque transmission device 10 of the second example also transmits torque between a first member 11 and a second member 12. When the torque transmission device 10 is used in a vehicle, the first member 11 and the second member 12 are vehicle-side members. The torque transmission device 10 includes a first input member 1 fixed to the first member 11, a second input member 2 fixed to the second member 12, a reaction force support member 3, a differential gear mechanism 7, and a differential limiting mechanism 5. The first input member 1, the second input member 2, the reaction force support member 3, the differential gear mechanism 7, and the differential limiting mechanism 5 are arranged coaxially (on the transmission axis X1). The reaction force support member 3 is supported by a support member provided separately from the torque transmission path of the torque transmission device 10. As with the first example, when the torque transmission device 10 of the second example is used in a vehicle, the support member is a vehicle body 300 (see FIGS. 6 to 8 , etc.). The support member is not limited to a non-rotating member such as the vehicle body 300, but may also be a rotating member (for example, a power transmission shaft) that rotates at the same rotational speed as the first member 11 and the second member 12.

[0033] The differential gear mechanism 7 includes a first rotating element E1, a second rotating element E2, and a third rotating element E3. In the second example, the first rotating element E1 is connected to the first input member 1, the second rotating element E2 is fixed to the reaction force support member 3, and the third rotating element E3 is connected to the second input member 2. That is, the first input member 1 is fixed to the first member 11 and also to the first rotating element E1. The second input member 2 is fixed to the second member 12 and also to the third rotating element E3. The reaction force support member 3 is supported by a support member provided separately from the torque transmission path and is fixed to the second rotating element E2.

[0034] As shown in FIG. 4 , the planetary gear mechanism of the torque transmission device 10 of the second example is a compound planetary gear mechanism (a so-called 2KH-type compound planetary gear mechanism) that includes two sun gears (a first sun gear S1 and a second sun gear S2) and two pinion gears (a first pinion gear PG1 and a second pinion gear PG2) of different diameters that rotate integrally and are supported by a common carrier CA. The first sun gear S1 meshes with the first pinion gear PG1, and the second pinion gear PG2 meshes with the second sun gear S2. This planetary gear mechanism does not include a ring gear. As shown in FIGS. 3 and 4 , in the torque transmission device 10 of the second example, the first rotating element E1 is the first sun gear S1, the second rotating element E2 is the second sun gear S2, and the third rotating element E3 is the carrier CA.

[0035] When rotational forces in different directions are input to the first input member 1 and the second input member 2, so-called reverse phase input occurs, as shown in FIG. 3 , the first input member 1 and the second input member 2 rotate relative to each other in opposite directions. That is, the first rotating element E1 (first sun gear S1) and the third rotating element E3 (carrier CA) rotate relative to each other in opposite directions, with the second rotating element E2 (second sun gear S2) as the fulcrum. That is, the first input member 1 and the second input member 2 are free to rotate relative to each other, and the rigidity of the torque transmission structure is at its lowest. When rotational forces in the same direction are input to the first input member 1 and the second input member 2, so-called in-phase input occurs, the first input member 1 and the second input member 2 do not rotate or rotate in the same direction (as described above for the movable mechanism 30, in this embodiment, the second rotating element E2 is rotatable within the range of relative rotation with the housing 4).

[0036] The configurations of the differential limiting mechanism 5 and the movable mechanism 30 are the same as those described above for the first example, and therefore a description thereof will be omitted.

[0037] According to the torque transmission device 10 described above with reference to the first and second examples, the first member 11 and the second member 12 are disposed via the differential gear mechanism 7, and the differential by the differential gear mechanism 7 is limited by the differential limiting mechanism 5, thereby changing the rigidity of the torque transmission structure between the first member 11 and the second member 12. Specifically, the rigidity of the torque transmission structure can be changed to be higher by limiting the differential by the differential limiting mechanism 5, and lower by not limiting the differential by the differential limiting mechanism 5. When the differential is not limited at all, in the case of an out-of-phase input in which the input to the first input member 1 and the input to the second input member 2 are in opposite directions, the first input member 1 and the second input member 2 rotate freely relative to each other, and the rigidity of the torque transmission structure is lowest. When the input to the first input member 1 and the input to the second input member 2 are in the same direction, the first input member 1 and the second input member 2 are less likely to rotate relative to each other, and the rigidity is high. Furthermore, when the differential limiting mechanism 5 completely limits the differential, the first input member 1 and the second input member 2 cannot rotate relative to each other, regardless of whether the input is in-phase or out-of-phase, and the rigidity of the torque transmission structure becomes the highest.

[0038] Such a torque transmission device 10 can be used in a stabilizer device or a suspension device for a vehicle. Figures 5 and 6 show an example in which the torque transmission device 10 is applied to a stabilizer device 100, and Figures 7 and 8 show an example in which the torque transmission device 10 is applied to a suspension device.

[0039] FIG. 5 is a schematic explanatory diagram from a top view showing an example of mounting the torque transmission device 10 to a stabilizer device 100 of a vehicle. FIG. 6 is a schematic explanatory diagram showing an example of mounting the torque transmission device 10 as viewed from a side from a cross section taken along line VI-VI in FIG. 5. In FIGS. 5 and 6, reference numerals 200, 201, 202, 203, 204, 210, and 220 denote suspension arms that support wheels W. Reference numeral 210 denotes a suspension arm that supports a first wheel (wheel W shown in FIG. 6), and reference numeral 220 denotes a suspension arm that supports a second wheel. Xw denotes a wheel axle that is the rotation axis of wheel W. The stabilizer device 100 includes a stabilizer arm that connects the suspension arm (210) of the first wheel to the suspension arm (220) of the second wheel. The torque transmission device 10 is disposed midway along the stabilizer arm so that the suspension arm (210) of the first wheel and the suspension arm (220) of the second wheel are connected via the torque transmission device 10.

[0040] As shown in Fig. 5, a first stabilizer arm 101 is connected to the suspension arm (210) of the first wheel, and a first input member 1 of the torque transmission device 10 is connected to the first stabilizer arm 101. A second stabilizer arm 102 is connected to the suspension arm (220) of the second wheel, and a second input member 2 of the torque transmission device 10 is connected to the second stabilizer arm 102. The first stabilizer arm 101 corresponds to the first member 11, and the second stabilizer arm 102 corresponds to the second member 12.

[0041] Fig. 7 is a schematic explanatory diagram from a top view showing an example of mounting the torque transmission device 10 to a suspension device of a vehicle. Fig. 8 is a schematic explanatory diagram from a side view taken along the line VIII-VIII in Fig. 7, showing an example of mounting the torque transmission device 10. In Figs. 7 and 8, reference numerals 105 and 106 denote shaft members connected to support members for wheels W (vehicle body 300 including suspension arms, etc.). The torque transmission device 10 is disposed midway along the shaft members so that a first shaft 105 connected to a support member for a first wheel and a second shaft 106 connected to a support member for a second wheel are connected via the torque transmission device 10.

[0042] As shown in Fig. 7 , a first shaft 105 is connected to a support member (vehicle body 300) on the side of the first wheel (corresponding to wheel W in Fig. 8 ), and a first input member 1 of the torque transmission device 10 is connected to the first shaft 105. A second shaft 106 is connected to a support member (vehicle body 300) on the side of the second wheel, and a second input member 2 of the torque transmission device 10 is connected to the second shaft 106. The first shaft 105 corresponds to the first member 11, and the second shaft 106 corresponds to the second member 12.

[0043] When the torque transmission device 10 allows a differential rotation between the first input member 1 and the second input member 2, it can absorb the difference in rotation between the first wheel and the second wheel, thereby improving the ride comfort of the vehicle. On the other hand, when the vehicle turns around a curve or the like, it can increase the roll rigidity of the vehicle by limiting the differential rotation between the first input member 1 and the second input member 2, thereby improving the running stability of the vehicle when turning.

[0044] As described above, in the torque transmission device 10 of this embodiment, the differential limiting mechanism 5 is provided with a drive device, which makes it possible to adjust whether or not to limit the differential between the first input member 1 and the second input member 2, and if so, the degree of limitation. Therefore, it is possible to appropriately switch between an operation mode that prioritizes ride comfort and an operation mode that prioritizes driving stability.

[0045] Other embodiments will be described below. Note that the configurations of the embodiments described below are not limited to being applied independently, and can also be applied in combination with the configurations of other embodiments as long as no contradiction occurs.

[0046] (1) In the above description, a double-pinion planetary gear mechanism (the torque transmission device 10 of the first example) and a 2KH planetary gear mechanism (the torque transmission device 10 of the second example) have been exemplified as planetary gear mechanisms constituting the differential gear mechanism 7. However, the planetary gear mechanism is not limited to these configurations, and may be, for example, a planetary gear mechanism having two sun gears of different diameters, a first pinion gear meshing with the large-diameter sun gear, a second pinion gear meshing with the small-diameter sun gear, a third pinion gear meshing with the second pinion gear and rotating integrally with the first pinion gear, the third pinion gear having a smaller diameter than the first pinion gear, and a common carrier rotatably supporting the first pinion gear, the second pinion gear, and the third pinion gear. In the case of a planetary gear mechanism having this configuration, the large diameter sun gear and the small diameter sun gear are either the first rotating element or the third rotating element, respectively, and the carrier is the second rotating element.

[0047] (2) In the above description, a planetary gear mechanism is used as an example of the differential gear mechanism 7. However, the differential gear mechanism 7 may be a bevel gear mechanism.

[0048] (3) In the above description, an example was given in which the reaction force support member 3 is supported on a support member (such as the vehicle body 300) via the movable mechanism 30. However, this does not preclude an example in which the reaction force support member 3 is fixed to a support member without the movable mechanism 30.

[0049] Summary of the embodiment The torque transmission device (10) described above will be briefly summarized below.

[0050] In one aspect, the torque transmission device (10) is a torque transmission device (10) that transmits torque between a first member (11) and a second member (12), and includes a first rotating element (E1), a second rotating element (E2), and a third rotating element (E3), and the torque transmission device (10) includes a differential gear mechanism (7) that is configured so that the rotational speeds of the first rotating element (E1), the second rotating element (E2), and the third rotating element (E3) are in the order described above; The torque transmission system includes a first input member (1) fixed to a rotating element (E1), a second input member (2) fixed to the second member (12) and fixed to the third rotating element (E3), a reaction force support member (3) supported by a support member (300) provided separately from the torque transmission path and fixed to the second rotating element (E2), and a differential limiting mechanism (5) that limits the differential between the first input member (1) and the second input member (2) and can change the limited state of the differential.

[0051] According to this configuration, by arranging the first member (11) and the second member (12) via the differential gear mechanism (7) and by limiting the differential movement by the differential gear mechanism (7) with the differential limiting mechanism (5), the rigidity of the torque transmission structure between the first member (11) and the second member (12) can be changed. Specifically, by limiting the differential movement with the differential limiting mechanism (5), the rigidity of the torque transmission structure can be changed to be higher, and by not limiting the differential movement with the differential limiting mechanism (5), the rigidity of the torque transmission structure can be changed to be lower. When the differential movement is not limited at all, in the case of an out-of-phase input in which the input to the first input member (1) and the input to the second input member (2) are in opposite directions, the first input member (1) and the second input member (2) rotate freely relative to each other, and the rigidity of the torque transmission structure becomes the lowest. When the input to the first input member (1) and the input to the second input member (2) are in-phase inputs in the same direction, the first input member (1) and the second input member (2) are less likely to rotate relative to each other, resulting in increased rigidity. Furthermore, when the differential limiting mechanism (5) completely limits differential movement, the first input member (1) and the second input member (2) cannot rotate relative to each other, regardless of whether the input is in-phase or out-of-phase, resulting in the highest rigidity of the torque transmission structure. Thus, this configuration makes it possible to realize a torque transmission mechanism that can appropriately change the transmitted torque while minimizing the size of the mechanism.

[0052] In the torque transmission device (10), it is preferable that the differential limiting mechanism (5) comprises an engagement device (50) that engages the first input member (1) and the second input member (2), and an electric actuator (60) that drives the engagement device (50).

[0053] According to this configuration, by changing the engagement state of the engagement device (50) using the actuator (60), it is possible to appropriately change whether or not to limit the differential movement between the first input member (1) and the second input member (2), and also to appropriately change the degree of limitation (limitation state) when limiting the differential movement. Furthermore, in the case of an electric actuator (60), energy can be easily supplied to the actuator (60) via a power line or the like. Therefore, compared to when the engagement device (50) is driven by, for example, hydraulic pressure, the torque transmission device (10) can be easily installed in the target device or the like.

[0054] Furthermore, it is preferable that the torque transmission device (10) is configured such that the differential limiting mechanism (5) includes an engagement device (50) that engages the first input member (1) and the second input member (2), and the engagement device (50) includes at least a pair of friction engagement members (53 (51, 52)), a pressing member (54) that presses the pair of friction engagement members (53 (51, 52)) in an opposing direction (L) in which the friction engagement members (51, 52) face each other, and a drive device (60) that drives the pressing member (54) in the opposing direction (L).

[0055] According to this configuration, by changing the engagement pressure of the engagement device (50) and thereby changing the engagement state of the engagement device (50) using the actuator (60), it is possible to appropriately change whether or not to limit the differential movement between the first input member (1) and the second input member (2), and to appropriately change the degree of limitation (limitation state) if the differential movement is limited. Furthermore, when limiting the differential movement, it is possible to continuously change the amount of differential movement between the first input member (51) and the second input member (52) by changing the engagement pressure of the engagement device (50). Therefore, it is possible to continuously change the rigidity of the torque transmission structure between the first member (11) and the second member (12), and it is also possible to continuously change the characteristics of torque transmission between the first member (11) and the second member (12).

[0056] Furthermore, it is preferable that the torque transmission device (10) is configured such that the second input member (2) comprises a cylindrical portion (22) formed in a cylindrical shape, the first input member (1) comprises an inner-arrangement portion (15) arranged in the internal space of the cylindrical portion (22) and on the same axis (X1) as the cylindrical portion (22), and the differential limiting mechanism (5) comprises an engagement device (50) arranged in the internal space of the cylindrical portion (22) and on the same axis (X1) as the cylindrical portion (22), and engages the cylindrical portion (22) with the inner-arrangement portion (15).

[0057] According to this configuration, there is no need to provide a separate housing for the engagement device (50), and the engagement device (50) that engages the inner portion (15) of the first input member (1) and the cylindrical portion (22) of the second input member (2) can be disposed in the internal space of the cylindrical portion (22) together with the inner portion (15), thereby facilitating the miniaturization of the torque transmission device (10). Furthermore, according to this configuration, the engagement device (50) of the differential limiting mechanism (5) is configured to engage the cylindrical portion (22) and the inner portion (15) inside the cylindrical portion (22), which facilitates the simplification of the coupling structure of the engagement device (50) between the first input member (1) and the second input member (2). Therefore, in this respect as well, the torque transmission device (10) can be easily miniaturized.

[0058] Furthermore, the torque transmission device (10) preferably further comprises a fixed support member (4) fixed to the support member (300), and a movable mechanism (30) provided between the fixed support member (4) and the reaction force support member (3) to allow relative rotation between the fixed support member (4) and the reaction force support member (3), and the movable mechanism (30) preferably comprises a movable support mechanism (34) that supports the reaction force support member (3) so that the fixed support member (4) and the reaction force support member (3) are rotatable relative to each other, and a biasing mechanism (36) that biases the fixed support member (4) and the reaction force support member (3) so that the phase of the relative rotation between them becomes a predetermined reference phase.

[0059] According to this configuration, elastic rotational vibration of the reaction force support member (3) relative to the support member (300) is permitted. That is, elastic rotational vibration of the first input member (1) and the second input member (2) relative to the support member (300) is permitted. Therefore, it is possible to absorb a part of the vibration component of the torque transmitted through the first member (11) and the second member (12). In addition, it is possible to elastically support the load transmitted to the first input member (1) and the second input member (2).

[0060] Furthermore, it is preferable that the torque transmission device (10) has the movable support mechanism (34) equipped with a movable member (32) movable in an axial direction (L) along the rotation axis (X1) of the reaction force support member (3), and a rotary-to-linear conversion mechanism that converts the relative rotation between the fixed support member (4) and the reaction force support member (3) into movement of the movable member (32) in the axial direction (L), the biasing mechanism (36) equipped with a biasing spring (35) that biases the movable member (32) in the axial direction (L), and the differential gear mechanism (7), the movable mechanism (30), and the differential limiting mechanism (5) are arranged coaxially with the rotation axis (X1) of the first rotating element (E1).

[0061] According to this configuration, the fixed support member (4) and the reaction force support member (3) can be made rotatable relative to each other, and the biasing spring can bias the fixed support member (4) and the reaction force support member (3) so that the phase of the relative rotation between them becomes a reference phase. Furthermore, according to this configuration, the differential gear mechanism (7), the movable mechanism (30), and the limited slip differential mechanism (5) are arranged coaxially with the rotation axis (X1) of the first rotating element (E1), making it easy to keep the radial dimension of the torque transmission device (10) small.

[0062] 1: First input member, 2: Second input member, 3: Reaction force support member, 4: Housing (fixed support member), 5: Limited slip differential mechanism, 7: Differential gear mechanism, 10: Torque transmission device, 11: First member, 12: Second member, 15: Inner arrangement portion, 22: Large diameter cylindrical portion (cylindrical portion), 30: Movable mechanism, 32: Movable member, 34: Movable support mechanism, 35: Biasing spring, 36: Biasing mechanism, 50: Engagement device, 51: First friction engagement member (each of a pair of friction engagement members (one of )), 52: second friction engagement member (each (the other of) the pair of friction engagement members), 53: pair of friction engagement members, 54: pressing member, 60: drive motor (drive device, electric actuator), 66: rotary-to-linear motion conversion mechanism, 300: vehicle body (support member provided separately from the torque transmission path), E1: first rotation element, E2: second rotation element, E3: third rotation element, L: axial direction, X1: transmission shaft (rotation axis of the reaction force support member, rotation axis of the first rotation element)

Claims

1. A torque transmission device that transmits torque between a first member and a second member, comprising a differential gear mechanism including a first rotating element, a second rotating element, and a third rotating element, configured such that the rotational speeds of the first rotating element, the second rotating element, and the third rotating element are in the order described; a first input member fixed to the first member and fixed to the first rotating element; a second input member fixed to the second member and fixed to the third rotating element; a reaction force support member supported by a support member provided separately from the torque transmission path and fixed to the second rotating element; and a differential limiting mechanism that limits the differential between the first input member and the second input member and can change the limiting state of the differential.

2. The torque transmission device according to claim 1, wherein the differential limiting mechanism includes an engaging device that engages the first input member and the second input member, and an electric actuator that drives the engaging device.

3. The torque transmission device according to claim 1, wherein the differential limiting mechanism includes an engaging device that engages the first input member and the second input member, and the engaging device includes at least a pair of friction engaging members, a pressing member that presses the pair of friction engaging members in a facing direction in which the respective friction engaging members face each other, and a driving device that drives the pressing member in the facing direction.

4. The torque transmission device according to claim 1, wherein the second input member includes a cylindrical portion formed in a cylindrical shape, the first input member includes an inner disposed portion disposed coaxially with the cylindrical portion in the internal space of the cylindrical portion, and the differential limiting mechanism includes an engaging device disposed coaxially with the cylindrical portion in the internal space of the cylindrical portion and engaging the cylindrical portion and the inner disposed portion.

5. The torque transmission device according to any one of claims 1 to 4, further comprising a fixed support member fixed to the support member, and a movable mechanism provided between the fixed support member and the reaction force support member and allowing relative rotation between the fixed support member and the reaction force support member, wherein the movable mechanism includes a movable support mechanism that supports the reaction force support member such that the fixed support member and the reaction force support member can rotate relative to each other, and a biasing mechanism that biases the relative rotation phase between the fixed support member and the reaction force support member to a predetermined reference phase.

6. The movable support mechanism includes a movable member that is movable in the axial direction along the rotation axis of the reaction force support member, and includes a rotation-linear motion conversion mechanism that converts the relative rotation between the fixed support member and the reaction force support member into the axial movement of the movable member. The biasing mechanism includes a biasing spring that biases the movable member in the axial direction. The differential gear mechanism, the movable mechanism, and the differential limiting mechanism are arranged coaxially with the rotation axis of the first rotating element. The torque transmission device according to claim 5.

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