Clutch device

Abstract

A cylindrical fork base portion (51) is provided on a radially outer side of a nut (42), and is capable of moving relative to the nut in an axial direction. Movement restricting portions (501, 502) are capable of restricting the axial-direction movement of the fork base portion (51) relative to the nut (42). An electric actuator (20) includes a spring (201) that is provided between the nut (42) and the fork base portion (51), and that is capable of urging the fork base portion (51) toward the nut (42) in the axial direction. A control portion (100) controls the operation of a rotary electric motor (30), thereby enabling a dog clutch (90) to be moved to a position at which contact with a first transmission portion (70) starts. A load of the spring (201) is set such that, after the dog clutch (90) and the first transmission portion (70) have started to come into contact with one another, the dog clutch (90) and the first transmission portion (70) can mesh with one another under the load of the spring (201).

Description

Clutch device CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Patent Application No. 2022-151720, filed on September 22, 2022, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a clutch device.

[0003] Conventionally, clutch devices capable of permitting or interrupting torque transmission between a first transmission part and a second transmission part that are rotatable relative to each other have been known. For example, a clutch device disclosed in Patent Document 1 is provided in a vehicle and is used to permit or interrupt torque transmission between an input shaft connected to the first transmission part and an output shaft connected to the second transmission part. In the clutch device disclosed in Patent Document 1, when a clutch sleeve moves toward the first transmission part and the internal teeth of the clutch sleeve mesh with the external teeth of the first transmission part, torque transmission between the first transmission part and the second transmission part is permitted.

[0004] Korean Patent No. 10-1666867

[0005] In the clutch device of Patent Document 1, the clutch sleeve is movable in translation, i.e., in the axial direction, as the fork translates. A weighting damper is provided between the fork and a translation member that translates when driven by the rotary motor. The weighting damper has first and second spring sleeves that are movable in the axial direction relative to the fork, and a waiting spring provided between the first and second spring sleeves.

[0006] The clutch device of Patent Document 1 uses a standby spring to prevent the occurrence of a phenomenon in which the internal teeth of the clutch sleeve and the external teeth of the first transmission part have difficulty engaging due to a difference in rotational speed between the first transmission part and the second transmission part. However, with the clutch device of Patent Document 1, if the load is reduced by waiting the stroke of the translation member while frictional force is generated when the internal teeth of the clutch sleeve and the external teeth of the first transmission part engage, the internal teeth of the clutch sleeve and the external teeth of the first transmission part may remain engaged for a long time. This may reduce the responsiveness of the clutch device and affect the vehicle's driving performance.

[0007] An object of the present disclosure is to provide a clutch device with high responsiveness.

[0008] A clutch device according to the present disclosure includes an electric actuator unit and a clutch unit. The electric actuator unit has a rotary electric motor, a rotary-translation unit, and a fork. The rotary-translation unit is capable of converting rotational motion caused by torque from the rotary electric motor into translational motion. The fork is capable of translational motion due to the translational motion of the rotary-translation unit.

[0009] The clutch unit includes a first transmission unit, a second transmission unit, and a dog clutch. The second transmission unit is rotatable relative to the first transmission unit. The dog clutch translates with translation of the fork and engages with the first transmission unit, thereby allowing torque transmission between the first transmission unit and the second transmission unit.

[0010] The rotation-translation unit includes a shaft and a nut. The shaft rotates when torque is input from the rotary electric motor. The annular or cylindrical nut is provided radially outside the shaft and moves axially relative to the shaft by translation when the shaft rotates.

[0011] The fork has a fork base and a movement restricting portion. The annular or cylindrical fork base is provided radially outward of the nut and is movable axially relative to the nut. The movement restricting portion restricts axial movement of the fork base relative to the nut.

[0012] The electric actuator unit has a spring that is disposed between the nut and the fork base and is capable of axially biasing the fork base against the nut.

[0013] In the present disclosure, while frictional force is generated when the dog clutch and the first transmission part are engaged, the movement restricting part restricts the relative axial movement of the fork base relative to the nut, thereby allowing torque from the rotary motor to be transmitted to the dog clutch via the nut, the movement restricting part, and the fork, without passing through a spring. This allows the rotary motor to apply a thrust force greater than the frictional force to the dog clutch, thereby shortening the waiting time due to meshing impact. This improves the responsiveness of the clutch device.

[0014] The clutch device according to the present disclosure further includes a control unit that controls the supply of electricity to the rotary electric motor, thereby controlling the operation of the rotary electric motor and the electric actuator unit.

[0015] In the present disclosure, the control unit controls the operation of the rotary motor to move the dog clutch to a position where it starts to contact the first transmission part. The spring load is set so that the dog clutch and the first transmission part can engage with each other under the spring load after the dog clutch and the first transmission part start to contact each other. This allows for a reduction in the power supplied to the rotary motor and a reduction in the power consumption of the clutch device.

[0016] The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which Fig. 1 is a schematic diagram showing a clutch device according to a first embodiment and a vehicle to which the same is applied, Fig. 2 is a cross-sectional view showing the clutch device according to the first embodiment, Fig. 3 is a cross-sectional view showing an electric actuator unit of the clutch device according to the first embodiment, Fig. 4 is a cross-sectional view showing a clutch unit of the clutch device according to the first embodiment, Fig. 5 is an exploded perspective view showing the clutch device according to the first embodiment, Fig. 6 is a schematic diagram showing an operating state of the clutch device according to the first embodiment, Fig. 7 is a schematic diagram showing an operating state of the clutch device according to the first embodiment, Fig. 8 is a schematic diagram showing an operating state of the clutch device according to the first embodiment, Fig. 9 is a schematic diagram showing an operating state of the clutch device according to the first embodiment, and Fig. 10 is a schematic diagram showing an operating state of the clutch device according to a comparative embodiment. 11 is a schematic diagram showing the operating state of the clutch device according to the first embodiment, FIG. 12 is a schematic diagram showing the operating state of the clutch device according to a comparative embodiment, FIG. 13 is a schematic diagram showing the operating state of the clutch device according to the first embodiment, FIG. 14 is a diagram showing an example of operation of the clutch device according to the first embodiment, FIG. 15 is a cross-sectional view showing the clutch device according to the second embodiment, FIG. 16 is a cross-sectional view showing the clutch device according to the third embodiment, FIG. 17 is a cross-sectional view showing the clutch device according to the fourth embodiment, FIG. 18 is a cross-sectional view showing a part of the clutch device according to the fourth embodiment, FIG. 19 is a cross-sectional view showing a part of the clutch device according to the fourth embodiment, and FIG. 20 is a cross-sectional view showing a part of the clutch device according to the fourth embodiment.

[0017] Hereinafter, clutch devices according to a number of embodiments will be described with reference to the drawings. Note that substantially the same components in the number of embodiments will be denoted by the same reference numerals, and descriptions thereof will be omitted.

[0018] First Embodiment A clutch device according to a first embodiment and a vehicle to which the clutch device is applied are shown in Fig. 1. The clutch device 10 is mounted on a vehicle 1 such as an electric vehicle.

[0019] The vehicle 1 is equipped with a motor generator 2, a reducer 17, a differential 9, a differential shaft 11, an axle case 16, a clutch device 10, wheel shafts 12, wheels 13, wheel shafts 14, wheels 15, an electronic control unit (hereinafter referred to as "ECU") 100 as a "control unit", and the like.

[0020] The motor generator 2 is used as a drive source for driving the vehicle 1, and is capable of outputting torque when energized. The motor generator 2 is capable of generating electricity through regenerative operation. The speed reducer 17 is capable of reducing the torque from the motor generator 2. The differential 9 is a differential device that distributes the torque from the speed reducer 17 to the wheels 13 and 15. The clutch device 10 is provided between the differential 9 and the wheels 13, and is used to allow or block the transmission of torque between the differential 9 and the wheels 13.

[0021] More specifically, the reducer 17 has a first gear shaft 3, a second gear shaft 4, a first small-diameter gear 5, a first large-diameter gear 6, a second small-diameter gear 7, and a second large-diameter gear 8. The first gear shaft 3 is connected to the motor generator 2 and is rotatable integrally with the motor generator 2. The first small-diameter gear 5 is coaxial with the first gear shaft 3 so as to be rotatable integrally with the first gear shaft 3. The second gear shaft 4 is parallel to the first gear shaft 3. The first large-diameter gear 6 has an outer diameter larger than that of the first small-diameter gear 5 and is capable of meshing with the first small-diameter gear 5, and is coaxial with the second gear shaft 4 so as to be rotatable integrally with the second gear shaft 4. The second small-diameter gear 7 has an outer diameter smaller than that of the first large-diameter gear 6, and is provided coaxially with the second gear shaft 4 so as to be rotatable integrally with the second gear shaft 4. The second large-diameter gear 8 has an outer diameter smaller than that of the second small-diameter gear 7, and is provided so as to be able to mesh with the second small-diameter gear 7. With this configuration, the torque from the motor generator 2 is reduced by the reducer 17 and output from the second large-diameter gear 8.

[0022] Here, "coaxial" does not necessarily mean that the axes of both are strictly aligned, but also includes a state in which they slightly intersect within the scope of error or common technical knowledge, and a state in which they are approximately parallel (the same applies below).

[0023] The differential 9 is provided to be connected to the second large diameter gear 8. One end of a differential shaft 11 is provided to be connected to the differential 9. The clutch device 10 is provided so that a first transmission part 70 (described later) is connected to the other end of the differential shaft 11. A second transmission part 80 (described later) of the clutch device 10 is connected to one end of a wheel shaft 12. The other end of the wheel shaft 12 is connected to a wheel 13. Here, the wheel 13 is, for example, the wheel on the rear left side of the vehicle 1.

[0024] One end of the wheel shaft 14 is connected to the differential 9. The other end of the wheel shaft 14 is connected to a wheel 15. Here, the wheel 15 is, for example, a wheel on the rear right side of the vehicle 1.

[0025] The axle case 16 is formed to be able to accommodate, for example, the motor generator 2, the reducer 17, the differential 9, the differential shaft 11, etc., and is provided on the vehicle 1. The axle case 16 has an axle case opening 160 and an axle case extension cylinder portion 161. The axle case opening 160 is formed coaxially with and on the axis of the differential shaft 11 so as to connect the internal space of the axle case 16 with the outside. The axle case extension cylinder portion 161 is formed to extend cylindrically from the axle case opening 160.

[0026] With the above-described configuration, when the clutch device 10 provides torque transmission between the first transmission part 70 connected to the differential shaft 11 and the second transmission part 80 connected to the wheel shaft 12, torque transmission between the motor generator 2 and the wheels 13 and 15 is permitted, allowing the vehicle 1 to run using the torque of the motor generator 2, or allowing the motor generator 2 to operate in a regenerative manner.

[0027] The ECU 100 is a small computer having a CPU as a calculation means, a ROM, a RAM, etc. as storage means, and an I / O as an input / output means. The ECU 100 executes calculations in accordance with a program stored in the ROM, etc., based on information such as signals from various sensors provided in various parts of the vehicle 1, and controls the operation of various devices and equipment of the vehicle 1. In this way, the ECU 100 executes a program stored in a non-transitory tangible recording medium. Execution of this program results in the execution of a method corresponding to the program.

[0028] The ECU 100 can control the operation of the motor generator 2 based on information such as signals from various sensors. The ECU 100 can also control the operation of the clutch device 10 by controlling the operation of a rotary electric motor 30 (described later).

[0029] <1> As shown in Figure 2, the clutch device 10 includes an electric actuator unit 20, a clutch unit 60, etc. The electric actuator unit 20 has a rotary motor 30, a rotary-translation unit 40, and a fork 50. The rotary-translation unit 40 is capable of converting rotational motion due to torque from the rotary motor 30 into translational motion. The fork 50 is capable of translational motion due to the translational motion of the rotary-translation unit 40.

[0030] The clutch unit 60 has a first transmission unit 70, a second transmission unit 80, and a dog clutch 90. The second transmission unit 80 is rotatable relative to the first transmission unit 70. The dog clutch 90 translates as the fork 50 translates and engages with the first transmission unit 70, thereby allowing torque to be transmitted between the first transmission unit 70 and the second transmission unit 80.

[0031] The rotation-translation unit 40 has a shaft 41 and a nut 42. The shaft 41 rotates when torque is input from the rotary motor 30. The cylindrical nut 42 is provided coaxially with the shaft 41 and radially outward of the shaft 41, and moves axially relative to the shaft 41 through translation when the shaft 41 rotates.

[0032] The fork 50 has a fork base 51 and movement restricting portions 501 and 502. The cylindrical fork base 51 is provided coaxially with the nut 42 and radially outward of the nut 42, and is movable in the axial direction relative to the nut 42. The movement restricting portions 501 and 502 are capable of restricting the relative axial movement of the fork base 51 with respect to the nut 42.

[0033] The electric actuator unit 20 has a spring 201 that is provided between the nut 42 and the fork base 51 and is capable of axially biasing the fork base 51 against the nut 42 .

[0034] 3 , the electric actuator unit 20 includes an actuator case 21, a bearing unit 22, an O-ring 23, a bearing 24, a bearing 25, a bearing 26, etc. The actuator case 21 is formed, for example, from metal, into a cylindrical shape with an internal space. The actuator case 21 has an axial opening 211 and a radial opening 212. The axial opening 211 is formed to open in the axial direction at one axial end of the actuator case 21 so as to connect the internal space of the actuator case 21 with the outside. The radial opening 212 is formed to open in the radial direction at the other axial end of the actuator case 21 so as to connect the internal space of the actuator case 21 with the outside.

[0035] The bearing portion 22 is formed into a cylindrical shape from, for example, metal. One axial end of the bearing portion 22 is located in the internal space of the actuator case 21, and the outer peripheral wall of the other end is fitted into the axial opening 211 of the actuator case 21. The O-ring 23 is formed into an annular shape from an elastic material such as rubber, and is provided between the other axial end of the bearing portion 22 and the axial opening 211. This provides an airtight or liquid-tight seal between the actuator case 21 and the bearing portion 22.

[0036] The bearings 24, 25, and 26 are, for example, ball bearings. The bearing 24 is provided so that its outer peripheral wall fits into the inner peripheral wall at the other axial end of the bearing portion 22. The bearing 25 is provided so that its outer peripheral wall fits into the inner peripheral wall at one axial end of the bearing portion 22. The bearing 26 is provided at the end of the actuator case 21 opposite the axial opening 211.

[0037] The rotary motor 30 includes a motor case 31, a stator 32, a coil 33, a motor shaft 34, a rotor 35, a magnet 36, and a bearing 37. The motor case 31 is formed of, for example, a metal in a cylindrical shape with a bottom, and the open end of the motor case 31 is connected to the other axial end of the bearing 22 so as to be coaxial with the bearing 22.

[0038] The stator 32 is formed into a cylindrical shape from a magnetic material such as laminated steel plate, and is fixed to the motor case 31 so that its outer peripheral wall fits into the inner peripheral wall of the motor case 31. The coil 33 is wound around a plurality of teeth (not shown) that protrude radially inward from the stator 32. The motor shaft 34 is formed into a substantially cylindrical rod shape from, for example, metal, and one axial end is supported by a bearing 37 and the motor case 31, and the other axial end is supported by a bearing 24 and the bearing portion 22.

[0039] The rotor 35 is formed in a cylindrical shape from a magnetic material such as an iron-based metal, and its inner peripheral wall is fitted onto the outer peripheral wall of the motor shaft 34, making it coaxial with the motor shaft 34. This allows the rotor 35 to rotate integrally with the motor shaft 34. The magnets 36 are provided on the outer peripheral wall of the rotor 35 so as to face the teeth of the stator 32. A plurality of magnets 36 are provided at equal intervals around the circumference of the rotor 35 so that their magnetic poles alternate.

[0040] The ECU 100 can control the operation of the rotary motor 30 by controlling the power supplied to the coil 33. When power is supplied to the coil 33, a rotating magnetic field is generated in the stator 32, causing the rotor 35 to rotate. This causes torque to be output from the rotor 35 and the motor shaft 34. In this way, the rotary motor 30 has the stator 32 and the rotor 35 that is rotatable relative to the stator 32, and can output torque from the rotor 35 when power is supplied.

[0041] The rotor 35 is disposed radially inside the stator 32 and is rotatable relative to the stator 32. The rotary motor 30 is an inner rotor type brushless DC motor.

[0042] The rotation-translation unit 40 includes a shaft 41, a nut 42, balls 43, etc. The shaft 41 is formed, for example, from metal in a substantially cylindrical rod shape, with one end supported by the bearing 25 and the bearing unit 22 and the other end supported by the bearing 26 and the actuator case 21. One end of the shaft 41 is formed in a cylindrical shape and is connected to the motor shaft 34 so as to be spline-coupled with the other axial end of the motor shaft 34. This causes the shaft 41 to rotate about its axis as the rotary motor 30 rotates. A shaft ball screw groove 411 is formed between the bearing 25 and the bearing 26 on the outer circumferential wall of the shaft 41, extending spirally from the bearing 25 side toward the bearing 26 side.

[0043] <4> The nut 42 has a cylindrical inner nut portion 44 that moves axially relative to the shaft 41 when the shaft 41 rotates, and a cylindrical outer nut portion 45 that is coaxial with the inner nut portion 44 and is located radially outside the inner nut portion 44 so as to be unable to rotate relative to the inner nut portion 44, and that can move and slide axially relative to the fork base 51.

[0044] <2> The nut 42 has a rotation restricting portion 400 that can restrict the relative rotation of the nut 42 with respect to the fork base portion 51 .

[0045] More specifically, the inner nut portion 44 has an inner nut tubular portion 441, an inner nut flange portion 442, and a nut ball screw groove 443. The inner nut tubular portion 441 is formed in a substantially cylindrical shape from, for example, metal. The inner nut flange portion 442 is formed integrally with the inner nut tubular portion 441 from the same material as the inner nut tubular portion 441 so as to extend radially outward from one end of the inner nut tubular portion 441. The nut ball screw groove 443 is formed so as to extend spirally along the inner circumferential wall of the inner nut tubular portion 441 from the inner nut flange portion 442 side to the opposite side of the inner nut flange portion 442. The inner nut portion 44 is disposed between the bearing 25 and the bearing 26 so that the inner nut tubular portion 441 is positioned coaxially with the shaft 41 and radially outward from the shaft 41.

[0046] The outer nut portion 45 has a first outer nut portion 46 and a second outer nut portion 47. The first outer nut portion 46 has a first outer nut body 461 and a nut external spline 462. The first outer nut body 461 is formed in a substantially cylindrical shape from, for example, metal. The nut external spline 462 is formed integrally with the first outer nut body 461 from the same material as the first outer nut body 461 so as to protrude radially outward from the outer peripheral wall of the first outer nut body 461 and extend linearly from one end to the other end in the axial direction. A plurality of nut external splines 462 are formed at equal intervals around the circumferential direction of the first outer nut body 461.

[0047] The first outer nut portion 46 is provided such that the inner peripheral wall of the first outer nut body 461 fits into the outer peripheral wall of the inner nut cylindrical portion 441 and is unable to rotate relative to the inner nut portion 44. Here, one end of the first outer nut portion 46 can abut against the inner edge portion of the inner nut flange portion 442.

[0048] The second outer nut portion 47 has a second outer nut cylindrical portion 471 and a second outer nut plate portion 472. The second outer nut cylindrical portion 471 is formed in a generally cylindrical shape from, for example, metal. The second outer nut plate portion 472 is formed integrally with the second outer nut cylindrical portion 471 from the same material as the second outer nut cylindrical portion 471 in an annular, plate-like shape and extends radially inward from one end of the second outer nut cylindrical portion 471.

[0049] The second outer nut portion 47 is provided such that the inner peripheral wall of the second outer nut cylinder portion 471 fits into the outer peripheral wall of the inner nut flange portion 442, making it unable to rotate relative to the inner nut portion 44. One axial end face of the second outer nut plate portion 472 can abut against the outer edge portion of the inner nut flange portion 442.

[0050] A plurality of balls 43 are provided between the shaft ball screw groove 411 of the shaft 41 and the nut ball screw groove 443 of the nut 42. The balls 43 are provided to be able to roll between the shaft ball screw groove 411 and the nut ball screw groove 443.

[0051] The rotation-translation unit 40 has end caps 401 and 402. The end caps 401 and 402 are formed into annular shapes from an elastic material such as rubber. The end cap 401 is provided between the end of the inner nut cylindrical portion 441 on the bearing 25 side and the shaft 41. The end cap 402 is provided between the end of the inner nut cylindrical portion 441 on the bearing 26 side and the shaft 41.

[0052] The fork 50 includes a fork base 51, a fork extension 52, a fork engagement portion 55, etc. The fork base 51 includes a fork base tubular portion 53, a fork base plate portion 54, a fork internal tooth spline 541, etc. The fork base tubular portion 53 is formed into a substantially cylindrical shape from, for example, metal. The inner diameter of one axial end of the fork base tubular portion 53 is larger than the inner diameter of the other axial end. Therefore, an annular, flat fork base step surface 531 is formed on the inner wall of the fork base tubular portion 53.

[0053] The fork base plate 54 is formed integrally with the fork base tubular portion 53 in an annular, plate-like shape from the same material as the fork base tubular portion 53 so as to extend radially inward from the other axial end of the fork base tubular portion 53. The fork internal splines 541 are formed integrally with the fork base plate 54 from the same material as the fork base plate 54 so as to protrude radially inward from the inner circumferential wall of the fork base plate 54 and extend linearly from one axial end to the other axial end. A plurality of fork internal splines 541 are formed at equal intervals around the circumferential direction of the fork base plate 54.

[0054] The fork extension 52 is formed integrally with the fork tubular base 53 from the same material as the fork tubular base 53 in a plate shape, extending radially outward from the outer peripheral wall of the fork tubular base 53. Here, the direction perpendicular to the surface of the fork extension 52 is parallel to the axial direction of the fork tubular base 53. The fork engagement 55 is formed integrally with the fork extension 52 from the same material as the fork extension 52, extending from the end of the fork extension 52 opposite the fork tubular base 53. The fork engagement 55 is formed to have a substantially semicircular shape when viewed from the axial direction of the fork tubular base 53. The fork engagement 55 is positioned so that the center of the semicircular shape connects to the fork extension 52.

[0055] A rotation prevention portion 56 is formed on the fork extension portion 52. The rotation prevention portion 56 is formed in the shape of a hole that passes through the fork extension portion 52 in the plate thickness direction.

[0056] The fork 50 is arranged so that the fork base 51 is located coaxially with the nut 42 and radially outward of the nut 42, and the fork extension 52 is located inside the radial opening 212 of the actuator case 21. Here, the nut 42 and the fork 50 are arranged so that the nut external spline 462 and the fork internal spline 541 are spline-coupled. As a result, the nut 42 and the fork 50 are arranged so that they can move relative to each other in the axial direction but cannot rotate relative to each other in the circumferential direction.

[0057] Here, the rotation restricting portion 400 is formed on the nut external spline 462 and, when engaged with the fork internal spline 541 , is capable of restricting the relative rotation of the nut 42 with respect to the fork base 51 .

[0058] An annular, flat fork step surface 532 is formed on the inner wall of the end of the fork tubular base portion 53 opposite the fork base plate portion 54. On the opposite side of the fork step surface 532 of the fork tubular base portion 53 from the fork base plate portion 54, a fork annular groove portion 533 is formed, recessed radially outward from the inner circumferential wall.

[0059] A washer 57 is provided on the end of the fork base tubular portion 53 opposite the fork base plate portion 54. The washer 57 is formed, for example, from a metal, in an annular, plate-like shape. The washer 57 is provided inside the fork base tubular portion 53 so that the outer edge of one end surface can abut against the fork step surface 532. A C-ring 58 is provided on the side of the washer 57 opposite the fork step surface 532. The C-ring 58 is formed, for example, from a metal, in a substantially C-shape. The C-ring 58 is provided on the fork base 51 so that its outer edge fits into the fork annular groove 533. This holds the washer 57 between the fork step surface 532 and the C-ring 58, preventing it from falling off the fork base 51.

[0060] The end of the second outer nut portion 47 of the nut 42 facing the second outer nut plate portion 472 can abut against the fork base stepped surface 531. The end of the second outer nut portion 47 of the nut 42 opposite the second outer nut plate portion 472 and the outer edge of the end face of the inner nut flange portion 442 opposite the second outer nut plate portion 472 can abut against the washer 57. Therefore, the nut 42 can move axially relative to the fork base 51 of the fork 50 within a range from the position where it abuts against the fork base stepped surface 531 to the position where it abuts against the washer 57.

[0061] Movement restricting portion 501 is formed on fork base step surface 531, and when it abuts against nut 42, is capable of restricting relative axial movement of fork base 51 toward bearing 22 with respect to nut 42. Movement restricting portion 502 is formed on washer 57, and when it abuts against nut 42, is capable of restricting relative axial movement of fork base 51 toward the opposite side of bearing 22 with respect to nut 42.

[0062] When the outer nut portion 45 of the nut 42 and the fork base 51 of the fork 50 move relative to each other in the axial direction, the nut external spline 462 of the outer nut portion 45 slides against the fork internal spline 541 of the fork base 51, and the outer peripheral wall of the second outer nut cylindrical portion 471 of the outer nut portion 45 slides against the inner peripheral wall of the fork base cylindrical portion 53 of the fork base 51.

[0063] The electric actuator unit 20 has a rotation-preventing shaft 27. The rotation-preventing shaft 27 is inserted into a rotation-preventing portion 56 formed on the fork extension portion 52 and is provided in the actuator case 21 with both ends fixed to the radial openings 212. This allows the fork 50 to move axially relative to the actuator case 21, the shaft 41, and the nut 42, while restricting its rotation relative to the actuator case 21. Furthermore, the rotation of the nut 42 relative to the fork base 51 of the fork 50 is restricted by a rotation-restricting portion 400.

[0064] The spring 201 is, for example, a coil spring formed by winding a flat metal plate into a coil. The spring 201 is disposed radially outward of the first outer nut portion 46 and radially inward of the fork base tubular portion 53, between the second outer nut plate portion 472 of the nut 42 and the fork base plate portion 54 of the fork base 51. One end of the spring 201 abuts against the second outer nut plate portion 472. The other end of the spring 201 abuts against the fork base plate portion 54. The spring 201 has a force that stretches in the axial direction. This allows the spring 201 to press the second outer nut portion 47 and the inner nut flange portion 442 against the washer 57 and to axially bias the fork base 51 against the nut 42.

[0065] With the above-described configuration, when rotary motor 30 rotates, motor shaft 34 rotates, and shaft 41 rotates. This causes balls 43 to roll between shaft ball screw groove 411 and nut ball screw groove 443. Because the rotation prevention shaft 27 restricts the relative rotation of fork 50 with respect to actuator case 21, and the rotation restriction unit 400 restricts the relative rotation of nut 42 with respect to fork 50, when balls 43 roll, nut 42 moves axially relative to shaft 41.

[0066] When the nut 42 moves relative to the shaft 41 in the axial direction opposite the bearing portion 22, the fork 50 moves relative to the shaft 41 in the axial direction opposite the bearing portion 22 due to the biasing force of the spring 201 until the nut 42 abuts against the movement restricting portion 501. When the nut 42 abuts against the movement restricting portion 501, the fork 50 moves relative to the shaft 41 in the axial direction opposite the bearing portion 22 due to the thrust of the nut 42, i.e., the thrust of the rotary motor 30.

[0067] On the other hand, when the nut 42 moves relative to the shaft 41 toward the bearing portion 22 in the axial direction, if the nut 42 abuts against the movement restricting portion 502, the fork 50 moves relative to the shaft 41 toward the bearing portion 22 in the axial direction due to the thrust of the nut 42, i.e., the thrust of the rotary motor 30.

[0068] In addition, the ball 43 that rolls in the nut ball screw groove 443 and reaches the end of the nut ball screw groove 443 on the end cap 401 side or the end cap 402 side passes through a circulation member not shown and is returned to the end of the nut ball screw groove 443 on the end cap 402 side or the end cap 401 side.

[0069] As shown in FIG. 4 , the clutch unit 60 includes a clutch case 61, a bearing 62, a C-ring 63, a bearing 64, a bearing 65, a sealing member 66, an oil seal 67, etc. The clutch case 61 is made of, for example, metal and is formed into a cylindrical shape with an internal space. The clutch case 61 includes an axial opening 611, an axial opening 612, a radial opening 613, a clutch case extension cylindrical portion 614, a clutch case stepped surface 615, a clutch case annular groove portion 616, etc. The axial opening 611 is formed to open in the axial direction at one axial end of the clutch case 61 so as to connect the internal space of the clutch case 61 with the outside. The axial opening 612 is formed to open in the axial direction at the other axial end of the clutch case 61 so as to connect the internal space of the clutch case 61 with the outside. The radial opening 613 is formed to open in the radial direction at the other axial end of the clutch case 61 so as to connect the internal space of the clutch case 61 with the outside. The clutch case extending cylindrical portion 614 is formed so as to extend cylindrically in the axial direction of the clutch case 61 from the axial opening portion 612 .

[0070] Clutch case step surface 615 is formed in an annular, flat shape at the axial center of the inner wall of clutch case 61. Clutch case annular groove 616 is formed on clutch case step surface 615 of clutch case 61 on the axial opening 611 side so as to be recessed annularly from the inner peripheral wall radially outward.

[0071] The bearings 62, 64, and 65 are, for example, ball bearings. The bearing 62 is provided so that its outer peripheral wall fits into the inner peripheral wall of the end of the clutch case 61 that is closer to the axial opening 611. Two bearings 62 are provided side by side in the axial direction. One of the bearings 62 is provided so that its outer edge can abut against the clutch case stepped surface 615. The number of bearings 62 is not limited to two, and only one may be provided.

[0072] The C-ring 63 is made of, for example, metal and is formed in a generally C-shape. The C-ring 63 is provided on the clutch case 61 so that its outer edge fits into the clutch case annular groove 616. The other bearing 62 is provided so that its outer edge can abut against the C-ring 63. As a result, the two bearings 62 are held between the clutch case stepped surface 615 and the C-ring 63, preventing them from falling off the clutch case 61.

[0073] <3> The first transmitting part 70 has a first external spline 74 at its end on the second transmitting part 80 side. The second transmitting part 80 has a second external spline 83 at its end on the first transmitting part 70 side. The dog clutch 90 has a cylindrical clutch sleeve 91 that is provided radially outward from the end of the second transmitting part 80 on the first transmitting part 70 side and is movable in the axial direction relative to the second transmitting part 80. The clutch sleeve 91 has an internal spline 93 that meshes with the second external spline 83 and can mesh with the first external spline 74 when it moves axially relative to the second external spline 83 toward the first external spline 74.

[0074] More specifically, the first transmission part 70 includes a first transmission part main body 71, a first transmission part flange part 72, a first annular plate part 73, a first external spline 74, etc. The first transmission part main body 71 is formed, for example, from a metal in a substantially cylindrical shape. The first transmission part flange part 72 is formed integrally with the first transmission part main body 71 in an annular and plate-like shape from the same material as the first transmission part main body 71 so as to extend radially outward from the outer peripheral wall at one end of the first transmission part main body 71. The first annular plate part 73 is formed integrally with the first transmission part flange part 72 in an annular and plate-like shape from the same material as the first transmission part flange part 72 so as to extend radially outward from the outer peripheral wall at one axial end of the first transmission part flange part 72.

[0075] The first external splines 74 are formed integrally with the first transmission part flange 72 from the same material as the first transmission part flange 72 so as to protrude radially outward from the outer peripheral wall of the other axial end of the first transmission part flange 72 and extend linearly to the first annular plate part 73. A plurality of first external splines 74 are formed at equal intervals around the circumferential direction of the first transmission part flange 72.

[0076] The bearing 64 is provided so that its outer peripheral wall fits into the axial opening 612 of the clutch case 61 and the inner peripheral wall of the clutch case extension tubular portion 614. Two bearings 64 are provided side by side in the axial direction. Note that the number of bearings 64 is not limited to two, and only one bearing 64 may be provided.

[0077] The first transmission part 70 is arranged so that the end of the first transmission part main body 71 opposite the first transmission part flange part 72 is located outside the clutch case 61, and the axial center of the first transmission part main body 71 is supported by the bearing 64 and the clutch case 61.

[0078] A first spline portion 711 is formed on the outer peripheral wall of the first transmission part body 71 on the side opposite to the first transmission part flange portion 72. The first spline portion 711 is formed so as to be spline-connectable to the end of the differential shaft 11 on the side opposite to the differential 9.

[0079] The second transmission part 80 has a second transmission part main body 81, a second annular plate part 82, a second external spline 83, etc. The second transmission part main body 81 is formed in a substantially cylindrical shape from, for example, a metal. The second annular plate part 82 is formed in an annular and plate-like shape integrally with the second transmission part main body 81 from the same material as the second transmission part main body 81 so as to extend radially outward from the outer peripheral wall at the axial center of the second transmission part main body 81.

[0080] The second external splines 83 are formed integrally with the second transmission part body 81 from the same material as the second transmission part body 81 so as to protrude radially outward from the outer peripheral wall of one axial end of the second transmission part body 81 and extend linearly up to the vicinity of the second annular plate part 82. A plurality of second external splines 83 are formed at equal intervals around the circumference of the second transmission part body 81.

[0081] The second transmitting part 80 is provided coaxially with the first transmitting part 70 such that the end face of the second transmitting part body 81 on the second external spline 83 side faces the end face of the first transmitting part flange part 72 opposite the first spline part 711. The second transmitting part 80 is supported by the bearing 62 and the clutch case 61 on the axial side opposite the second external spline 83 with respect to the second annular plate part 82. Here, the second annular plate part 82 can abut against the inner edge part of one of the two bearings 62. This prevents the second transmitting part 80 from falling off the clutch case 61.

[0082] The bearing 65 is provided so that its inner peripheral wall fits into the outer peripheral wall of the end of the first transmission part body 71 opposite the first spline part 711, and its outer peripheral wall fits into the inner peripheral wall of the end of the second transmission part body 81 on the second external spline 83 side. As a result, the end of the first transmission part body 71 opposite the first spline part 711 is supported by the bearing 65, the second transmission part body 81, the bearing 62, and the clutch case 61.

[0083] The outer diameter of the first transmission part flange 72 of the first transmission part 70 is approximately the same as the outer diameter of the end of the second transmission part body 81 of the second transmission part 80 on the first transmission part 70 side. Furthermore, the number of first external splines 74 in the circumferential direction of the first transmission part flange 72 is the same as the number of second external splines 83 in the circumferential direction of the second transmission part body 81.

[0084] A second spline portion 811 is formed on the inner peripheral wall at the axial center of the second transmission part body 81. The second spline portion 811 is formed so as to be spline-connectable to the end of the wheel shaft 12 opposite to the wheel 13.

[0085] The sealing member 66 is formed of, for example, a metal in a substantially circular plate shape. The sealing member 66 is provided on the first transmission part 70 side with respect to the second spline part 811 of the second transmission part body 81 so that its outer peripheral wall fits into the inner peripheral wall of the second transmission part body 81. The sealing member 66 can prevent liquid such as lubricating oil from leaking from the differential shaft 11 side to the wheels 13 side via the inside of the first transmission part body 71 and the inside of the second transmission part body 81.

[0086] The oil seal 67 is formed into an annular shape from an elastic material such as rubber, a metal ring, or the like. The outer peripheral wall of the oil seal 67 fits into the inner peripheral wall of the axial opening 611 of the clutch case 61, and the inner edge is provided so as to be able to slide against the outer peripheral wall of the end of the second transmission part body 81 opposite to the second external spline 83. This provides an airtight or liquidtight seal between the axial opening 611 of the clutch case 61 and the second transmission part body 81.

[0087] The dog clutch 90 includes a clutch sleeve 91. The clutch sleeve 91 includes a sleeve body 92, an internal spline 93, a fork engagement recess 94, and the like. The sleeve body 92 is formed, for example, from a metal and has a generally cylindrical shape. The internal spline 93 is formed integrally with the sleeve body 92 from the same material as the sleeve body 92 so as to protrude radially inward from the inner circumferential wall at one axial end of the sleeve body 92 and extend linearly to the other end. A plurality of internal splines 93 are formed at equal intervals around the circumference of the sleeve body 92. The number of internal splines 93 around the circumference of the sleeve body 92 is the same as the number of first external splines 74 around the circumference of the first transmission part flange 72, and the number of second external splines 83 around the circumference of the second transmission part body 81.

[0088] The fork engagement recess 94 is formed in an annular shape so as to be recessed radially inward from the outer peripheral wall on one axial end side of the sleeve body 92. An annular, flat annular surface 941 is formed on one axial side of the fork engagement recess 94 on the sleeve body 92. An annular, flat annular surface 942 is formed on the other axial side of the fork engagement recess 94 on the sleeve body 92.

[0089] The dog clutch 90 is provided so that the clutch sleeve 91 is coaxial with the second transmission part body 81 and is located radially outward from the end of the second transmission part body 81 on the first transmission part 70 side. The dog clutch 90 is spline-coupled to the second transmission part 80 by the internal spline 93 meshing with the second external spline 83. This allows the dog clutch 90 to move axially relative to the second transmission part 80 but not rotate circumferentially relative to the second transmission part 80.

[0090] When the clutch sleeve 91 of the dog clutch 90 moves axially relative to the second transmission part body 81 toward the first transmission part 70, the internal spline 93 meshes with the first external spline 74. When the internal spline 93 meshes with the first external spline 74, the dog clutch 90 restricts relative rotation between the first transmission part 70 and the second transmission part 80, and allows torque transmission between the first transmission part 70 and the second transmission part 80.

[0091] On the other hand, when the clutch sleeve 91 moves axially relative to the first transmitting part 70 toward the second transmitting part 80, the internal spline 93 is disengaged from the first external spline 74. When the internal spline 93 is disengaged from the first external spline 74, relative rotation between the first transmitting part 70 and the second transmitting part 80 is permitted, and the transmission of torque between the first transmitting part 70 and the second transmitting part 80 is interrupted.

[0092] The axial length of the clutch sleeve 91 is shorter than the length from the end of the second transmission part body 81 on the first transmission part 70 side to the second annular plate part 82, and longer than the length from the end of the first transmission part flange part 72 on the second transmission part 80 side to the first annular plate part 73. The clutch sleeve 91 is movable in the axial direction relative to the second transmission part 80 and the first transmission part 70, between the first annular plate part 73 and the second annular plate part 82. When the clutch sleeve 91 abuts against the first annular plate part 73, the internal spline 93 meshes with the first external spline 74 and the second external spline 83. When the clutch sleeve 91 abuts against the second annular plate part 82, the internal spline 93 meshes with the second external spline 83 but does not mesh with the first external spline 74.

[0093] "9" The electric actuator unit 20 and the clutch unit 60 are integrally provided so that the radial opening 212 communicates with the radial opening 613 of the clutch case 61. Here, the actuator case 21 and the clutch case 61 are fastened together by, for example, bolts or the like (not shown).

[0094] In this way, by assembling the electric actuator unit 20 and the clutch unit 60 separately and configuring them so that they can be attached to each other, it becomes easier to replace the electric actuator unit 20 or the clutch unit 60 in the event of a malfunction.

[0095] When the electric actuator unit 20 and the clutch unit 60 are provided integrally, the fork engagement portion 55 of the fork 50 is fitted into the fork engagement recess 94 of the dog clutch 90. Therefore, when the rotary motor 30 rotates in the forward direction and the nut 42 moves relative to the shaft 41 in the opposite direction from the bearing unit 22, the fork 50 also moves relative to the shaft 41 in the opposite direction from the bearing unit 22. As a result, the fork engagement portion 55 comes into contact with the annular surface 942 of the fork engagement recess 94, pressing the dog clutch 90 toward the first transmission unit 70. As a result, the dog clutch 90 moves toward the first transmission unit 70, and the internal spline 93 meshes with the first external spline 74.

[0096] On the other hand, when the rotary motor 30 rotates in the reverse direction and the nut 42 moves toward the bearing 22 relative to the shaft 41, the fork 50 also moves toward the bearing 22 relative to the shaft 41. This causes the fork engagement portion 55 to come into contact with the annular surface 941 of the fork engagement recess 94, pressing the dog clutch 90 toward the side opposite the first transmitting portion 70. This causes the dog clutch 90 to move toward the side opposite the first transmitting portion 70, and the internal spline 93 and the first external spline 74 are disengaged from each other.

[0097] 1, for example, the clutch device 10 is provided between the axle case 16 and the wheel 13 so as to abut against the outer wall of the axle case 16. Here, the clutch device 10 is provided on the axle case 16 so that the outer peripheral wall of the clutch case extension tubular portion 614 fits into the inner peripheral wall of the axle case extension tubular portion 161. This allows the clutch device 10 to be easily positioned relative to the axle case 16.

[0098] Here, for example, the axle case 16 may not be provided with the axle case extension tubular portion 161, and the clutch device 10 may be provided so that the outer peripheral wall of the clutch case extension tubular portion 614 fits into the inner peripheral wall of the axle case opening 160. Even in this case, the clutch device 10 can be easily positioned relative to the axle case 16.

[0099] FIG. 5 shows an exploded perspective view of the clutch device 10, which clarifies the shape and arrangement of each member that constitutes the clutch device 10.

[0100] <3> Chamfered portions 741, 742, 931, and 932 are formed on the end of the first external spline 74 on the second external spline 83 side and the end of the internal spline 93 on the first external spline 74 side.

[0101] 6 , at the end of the first external spline 74 on the second external spline 83 side, a chamfered portion 741 is formed on one circumferential side of the first transmitting part 70, and a chamfered portion 742 is formed on the other circumferential side of the first transmitting part 70. Here, the chamfered portion 741 and the chamfered portion 742 are each formed in a flat shape inclined at approximately 45 degrees with respect to a straight line L1 along the extension direction of the first external spline 74. Therefore, when viewed from the radial outside of the first transmitting part 70, the first external spline 74 is formed in a shape that is line-symmetrical with respect to the straight line L1.

[0102] At the end of the internal spline 93 on the first external spline 74 side, a chamfered portion 931 is formed on one circumferential side of the second transmitting part 80, and a chamfered portion 932 is formed on the other circumferential side of the second transmitting part 80. Here, the chamfered portion 931 and the chamfered portion 932 are each formed in a flat shape inclined at approximately 45 degrees with respect to a straight line L2 along the extension direction of the internal spline 93. Therefore, when viewed from the radial outside of the second transmitting part 80, the internal spline 93 is formed in a shape that is line-symmetrical with respect to the straight line L2.

[0103] Next, the operation of the clutch device 10 will be described with reference to FIGS.

[0104] 6 to 9 show the shape and arrangement of each member constituting the clutch device 10 in a schematic manner, and differ from the actual shape and arrangement of each member.

[0105] 6 , when the rotary motor 30 is not energized, the nut 42 abuts against the movement restricting portion 502, and the internal spline 93 is spaced apart from the first external spline 74. Therefore, the internal spline 93 is not engaged with the first external spline 74, and transmission of torque between the first transmitting portion 70 and the second transmitting portion 80 is interrupted.

[0106] 7 , when the rotary motor 30 is energized, the shaft 41 rotates, and the nut 42 translates and moves to one side in the axial direction relative to the shaft 41. As a result, the nut 42 moves away from the movement restricting portion 502 and compresses the spring 201. As a result, the spring 201 biases the fork 50 and the dog clutch 90, and the internal spline 93 moves toward the first external spline 74. As a result, the end of the internal spline 93 on the first external spline 74 side comes into contact with the end of the first external spline 74 on the internal spline 93 side.

[0107] "10" Here, while a clearance is formed between the nut 42 and the movement restricting portion 501, the biasing force of the spring 201 acts on the internal spline 93. Therefore, when the end of the internal spline 93 collides with the end of the first external spline 74, the impact force can be prevented from being transmitted to the nut 42, the shaft 41, and the rotary motor 30, thereby protecting these components.

[0108] Furthermore, while a clearance is formed between the nut 42 and the movement restricting portion 501, when the differential rotation, which is the difference in rotational speed between the first transmitting portion 70 and the second transmitting portion 80, is equal to or greater than a predetermined value, the internal spline 93 and the first external spline 74 are ratcheted together to prevent the internal spline 93 from meshing with the first external spline 74. This makes it possible to suppress the impact that would otherwise be generated when the clutch device 10 is activated and transmitted to the driver of the vehicle 1, for example.

[0109] Furthermore, while a clearance is formed between the nut 42 and the movement restricting portion 501, when the differential rotation between the first transmission portion 70 and the second transmission portion 80 decreases to a predetermined value or less, the spring force of the spring 201 causes the fork 50 and the dog clutch 90 to move in a parallel direction, thereby allowing the internal spline 93 to mesh with the first external spline 74.

[0110] As described above, in this embodiment, at the contact start position between the end of the internal spline 93 and the end of the first external spline 74, ratcheting is possible by the spring 201 serving as a "waiting spring," and the nut 42 and the fork 50 are set to an intermediate floating position, which is a position between the movement restricting portion 501 and the movement restricting portion 502, so that the internal spline 93 and the first external spline 74 can mesh with each other under the load of the spring 201. This makes it possible to achieve both ratcheting between the internal spline 93 and the first external spline 74 and meshing by the spring 201.

[0111] 8 , when the nut 42 and fork 50 move further in translation due to the rotation of the rotary motor 30 and the shaft 41, the nut 42 comes into contact with the movement restricting portion 501 while compressing the spring 201. Therefore, torque from the rotary motor 30 can be transmitted to the dog clutch 90 via the nut 42, the movement restricting portion 501, and the fork 50 without passing through the spring 201. As a result, even when the differential rotation between the first transmitting portion 70 and the second transmitting portion 80 is greater than or equal to a predetermined value and a large frictional force is generated between the side surface of the internal spline 93 and the side surface of the first external spline 74 after the internal spline 93 and the first external spline 74 have started to mesh, a thrust greater than the frictional force can be applied from the rotary motor 30 to the dog clutch 90, and the internal spline 93 can be reliably and quickly meshed with the first external spline 74.

[0112] 9 , when the internal spline 93 and the first external spline 74 are engaged, if the supply of electricity to the rotary motor 30 is stopped, the urging force of the spring 201 causes the nut 42 to move relative to the fork 50 toward the rotary motor 30 and come into contact with the movement restricting portion 502. In this state, if the rotary motor 30 is energized to rotate the shaft 41 in the reverse direction, the nut 42 translates toward the rotary motor 30 while still in contact with the movement restricting portion 502. As a result, the fork 50 and the dog clutch 90 also move in a direction away from the first transmission part 70, and the engagement between the internal spline 93 and the first external spline 74 is released.

[0113] In this manner, in the present embodiment, when the internal spline 93 and the first external spline 74 are engaged, i.e., when the engagement of the dog clutch 90 is maintained, the power supplied to the rotary motor 30 is reduced and the urging force of the spring 201 keeps the nut 42 in contact with the movement restricting portion 502, thereby improving the responsiveness of the disengagement of the dog clutch 90. Furthermore, by reducing the power supplied to the rotary motor 30 when the engagement of the dog clutch 90 is maintained, the power consumption of the clutch device 10 can be reduced.

[0114] "2" In this embodiment, the ECU 100 controls the operation of the rotary motor 30 to quickly move the internal spline 93 of the dog clutch 90 to a position where it starts to contact the first external spline 74 (see FIGS. 6 and 7). Furthermore, the load of the spring 201 is set so that the internal spline 93 and the first external spline 74 can mesh with each other under the load of the spring 201 after the internal spline 93 and the first external spline 74 start to contact each other (see FIG. 7). Furthermore, after the internal spline 93 and the first external spline 74 start to mesh with each other, the nut 42 is brought into contact with the movement restricting portion 501, thereby applying a thrust force greater than or equal to the frictional force from the rotary motor 30 to the dog clutch 90, thereby further moving the internal spline 93 relative to the first external spline 74 (see FIG. 8). This allows the internal spline 93 and the first external spline 74 to reliably and quickly complete meshing.

[0115] Next, the present embodiment will be compared with a comparative embodiment to clarify the advantages of the present embodiment over the comparative embodiment.

[0116] 10 , the comparative example differs from the present embodiment in that the internal spline 93 does not have a chamfered portion 931, a chamfered portion 932, and the first external spline 74 does not have a chamfered portion 741, a chamfered portion 742. The comparative example also differs from the present embodiment in that the fork 50 does not have a movement restricting portion 501. When the nut 42 abuts against a movement restricting portion 505 formed on the actuator case 21, translation of the nut 42 in the direction opposite to the rotary motor 30 is restricted.

[0117] 10 , in the comparative example, the internal spline 93 does not have a chamfered portion 931, a chamfered portion 932, and the first external spline 74 does not have a chamfered portion 741, a chamfered portion 742. Therefore, the distance D1 between the ends of the first external splines 74 that are adjacent in the circumferential direction of the first transmitting part 70 on the internal spline 93 side is relatively small, and the dimension D2 of the end of the internal spline 93 that is adjacent to the first external spline 74 in the circumferential direction of the second transmitting part 80 is relatively large. Therefore, the insertion allowance D3, which is the difference between D1 and D2, is small. Therefore, when the differential rotation between the first transmitting part 70 and the second transmitting part 80 is equal to or greater than a predetermined value, it may be difficult to insert the internal spline 93 between the first external splines 74, i.e., to mesh the internal spline 93 with the first external spline 74.

[0118] Furthermore, in the comparative example, although the biasing force of the spring 201 acts on the internal spline 93, the internal spline 93 does not have the chamfered portions 931 and 932, and the first external spline 74 does not have the chamfered portions 741 and 742, which may make it difficult to ratchet the internal spline 93 and the first external spline 74. When the differential rotation between the first transmitting part 70 and the second transmitting part 80 is equal to or greater than a predetermined value, if the internal spline 93 and the first external spline 74 mesh with each other, there is a risk of a large shock occurring at the time of meshing.

[0119] 11 , in this embodiment, the internal spline 93 is formed with chamfered portions 931 and 932, and the first external spline 74 is formed with chamfered portions 741 and 742. Therefore, of two first external splines 74 adjacent to each other in the circumferential direction of the first transmitting part 70, an insertion allowance D6, which is the difference between a distance D4 from a side surface 743 on the chamfered portion 741 side of one first external spline 74 to an end of the chamfered portion 742 on the chamfered portion 741 side of the other first external spline 74, and a distance D5 from the side surface 933 on the chamfered portion 931 side of one internal spline 93 to the chamfered portion 932, is larger than the insertion allowance D3 in the comparative embodiment. Therefore, even if the differential rotation between the first transmission part 70 and the second transmission part 80 is equal to or greater than a predetermined value, it is easy to insert the internal spline 93 between the first external splines 74, i.e., to mesh the internal spline 93 with the first external spline 74.

[0120] Furthermore, in the present embodiment, the internal spline 93 is formed with the chamfered portions 931 and 932, the first external spline 74 is formed with the chamfered portions 741 and 742, and while a clearance is formed between the nut 42 and the movement restricting portion 501, the biasing force of the spring 201 acts on the internal spline 93. Therefore, when the differential rotation between the first transmitting portion 70 and the second transmitting portion 80 is greater than or equal to a predetermined value, the internal spline 93 and the first external spline 74 are ratcheted together, thereby preventing the internal spline 93 from meshing with the first external spline 74. This makes it possible to suppress abnormal meshing, which is a phenomenon in which the internal spline 93 meshes with the first external spline 74 when the differential rotation between the first transmitting portion 70 and the second transmitting portion 80 is greater than or equal to a predetermined value.

[0121] In this embodiment, when the rotational speed of the first transmitting part 70 is higher than the rotational speed of the second transmitting part 80, the internal spline 93 moves toward the first external spline 74, causing the chamfered portion 931 of the internal spline 93 to come into contact with the chamfered portion 741 of the first external spline 74. At this time, if the differential rotation between the first transmitting part 70 and the second transmitting part 80 is equal to or greater than a predetermined value, the internal spline 93 moves in a direction away from the first external spline 74 while the chamfered portion 931 slides on the chamfered portion 741, thereby allowing the internal spline 93 and the first external spline 74 to ratchet together.

[0122] On the other hand, when the rotational speed of the first transmitting part 70 is lower than the rotational speed of the second transmitting part 80, as the internal spline 93 moves toward the first external spline 74, the chamfered portion 932 of the internal spline 93 comes into contact with the chamfered portion 742 of the first external spline 74. At this time, if the differential rotation between the first transmitting part 70 and the second transmitting part 80 is greater than or equal to a predetermined value, the chamfered portion 932 slides against the chamfered portion 742, and the internal spline 93 moves in a direction away from the first external spline 74, thereby causing the internal spline 93 and the first external spline 74 to ratchet together.

[0123] In the present embodiment, the chamfered portions 741 and 742 are each formed in a flat shape inclined at approximately 45 degrees with respect to a straight line L1 along the extension direction of the first external spline 74. The chamfered portions 931 and 932 are each formed in a flat shape inclined at approximately 45 degrees with respect to a straight line L2 along the extension direction of the internal spline 93 (see FIG. 6). Therefore, whether the rotational speed of the first transmitting part 70 is higher or lower than the rotational speed of the second transmitting part 80, the internal spline 93 and the first external spline 74 can be easily ratcheted together.

[0124] Furthermore, in this embodiment, the first external spline 74 is formed in a shape that is line-symmetrical about the straight line L1 when viewed from the radial outside of the first transmitting part 70. The internal spline 93 is formed in a shape that is line-symmetrical about the straight line L2 when viewed from the radial outside of the second transmitting part 80 (see FIG. 6). Therefore, the first external spline 74 and the internal spline 93 can be easily machined, and the clutch device 10 can be easily manufactured.

[0125] 12 , in the comparative example, when the internal spline 93 and the first external spline 74 start to mesh, if the differential rotation between the first transmitting part 70 and the second transmitting part 80 is equal to or greater than a predetermined value, a large frictional force is generated between the side surface of the internal spline 93 and the side surface of the first external spline 74. Here, only the biasing force of the spring 201 acts on the internal spline 93. Therefore, if the frictional force between the internal spline 93 and the first external spline 74 is greater than the biasing force of the spring 201, the internal spline 93 cannot be moved further relative to the first external spline 74. This may make it difficult to reliably mesh the internal spline 93 and the first external spline 74.

[0126] 13 , in this embodiment, by bringing the nut 42 into contact with the movement restricting portion 501, the thrust of the rotary motor 30 can be applied to the dog clutch 90 via the fork 50. Therefore, even if the differential rotation between the first transmitting portion 70 and the second transmitting portion 80 is greater than or equal to a predetermined value and a large frictional force is generated between the side surface of the internal spline 93 and the side surface of the first external spline 74 when the internal spline 93 and the first external spline 74 have started to mesh, the rotary motor 30 can apply a thrust greater than the frictional force to the dog clutch 90, thereby allowing the internal spline 93 to further move relative to the first external spline 74. This allows the internal spline 93 to mesh with the first external spline 74 reliably and quickly.

[0127] Next, an example of the operation of the clutch device 10 according to this embodiment will be described.

[0128] At time t0 in FIG. 14, the rotation speed of the wheel 13 and the second transmission part 80 is R0.

[0129] 14, when the motor generator 2 starts to rotate at time t1, the rotation speed of the first transmission unit 70 increases, thereby reducing the differential rotation speed between the first transmission unit 70 and the second transmission unit 80 after time t1.

[0130] When the rotary motor 30 of the clutch device 10 starts to rotate at time t2, the stroke amount, which is the axial movement of the dog clutch 90, increases. Here, the stroke amount of the dog clutch 90 in a state (initial position) in contact with the second annular plate portion 82 is set to 0. When the dog clutch 90 in a state in contact with the second annular plate portion 82 moves toward the first annular plate portion 73, the stroke amount increases.

[0131] At time t3, when the rotation speed of the first transmission part 70 becomes R1 and the differential rotation between the first transmission part 70 and the second transmission part 80 becomes equal to or less than the target differential rotation, the stroke amount becomes S1 and the end of the internal spline 93 on the first external spline 74 side comes into contact with the end of the first external spline 74 on the internal spline 93 side (see Figure 7).

[0132] In this embodiment, the internal spline 93 is formed with chamfered portions 931 and 932, and the first external spline 74 is formed with chamfered portions 741 and 742. Therefore, even if the differential rotation between the first transmitting part 70 and the second transmitting part 80 is equal to or greater than a predetermined value below the target differential rotation, the internal spline 93 can be inserted between the first external splines 74 (see FIG. 11 ). Therefore, engagement, i.e., meshing, at a high differential rotation is possible. Therefore, the target differential rotation can be set large, and the target differential rotation can be expanded.

[0133] After time t3, the dog clutch 90 moves toward the first annular plate portion 73 due to the biasing force of the spring 201. Therefore, the stroke amount increases in accordance with the movement of the dog clutch 90.

[0134] At time t4, the stroke amount becomes S2, and the internal spline 93 and the first external spline 74 begin to mesh with each other, causing the nut 42 to come into contact with the movement restricting portion 501 (see FIG. 8 ). At this time (time t4), a frictional force N1 acts as a load between the internal spline 93 and the first external spline 74 due to the differential rotation between the first transmitting portion 70 and the second transmitting portion 80.

[0135] In this embodiment, after time t4, a thrust force equal to or greater than the friction force N1 is applied from the rotary motor 30 to the dog clutch 90, thereby increasing the stroke amount of the dog clutch 90. In this way, in this embodiment, engagement, i.e., meshing, is possible under a high load.

[0136] After time t4, the rotation speed of the first transmission part 70 coincides with the rotation speed R0 of the second transmission part 80.

[0137] At time t5, the stroke amount becomes S3, the dog clutch 90 contacts the first annular plate portion 73, and the meshing between the internal spline 93 and the first external spline 74 is completed.

[0138] An example of operation of the comparative embodiment is shown by a dashed line in Fig. 14. At time t3, the differential rotation between the first transmitting part 70 and the second transmitting part 80 is equal to or greater than a predetermined value, so in the comparative embodiment, the internal spline 93 cannot be inserted between the first external splines 74, i.e., the internal spline 93 cannot be meshed with the first external spline 74 (see Fig. 10). Therefore, the state in which the internal spline 93 cannot be meshed with the first external spline 74 continues even after time t3.

[0139] Another example of operation of the comparative embodiment is shown by the two-dot chain line in FIG. 14 . At time t4, when the internal spline 93 and the first external spline 74 begin to mesh, the differential rotation between the first transmitting part 70 and the second transmitting part 80 is greater than a predetermined value, generating a frictional force N1 between the internal spline 93 and the first external spline 74. In the comparative embodiment, only the biasing force of the spring 201 acts on the internal spline 93. Therefore, the frictional force N1 between the internal spline 93 and the first external spline 74 is greater than the biasing force of the spring 201, preventing the internal spline 93 from moving further relative to the first external spline 74 (see FIG. 12 ). Therefore, the state in which the internal spline 93 cannot move further relative to the first external spline 74 continues even after time t4.

[0140] At time t6, the frictional force between the internal spline 93 and the first external spline 74 becomes equal to or less than N2 (a value smaller than N1) and becomes smaller than the biasing force of the spring 201, and the internal spline 93 can be further moved relative to the first external spline 74. As a result, the stroke amount increases after time t6, and at time t7, the meshing between the internal spline 93 and the first external spline 74 is completed.

[0141] Thus, in the comparative example, after the internal spline 93 and the first external spline 74 start to mesh (time t4), it is necessary to wait until the frictional force between the internal spline 93 and the first external spline 74 becomes smaller than the biasing force of the spring 201 (time t6) before operating to complete the meshing between the internal spline 93 and the first external spline 74.

[0142] On the other hand, in this embodiment, after the internal spline 93 and the first external spline 74 start to mesh with each other (time t4), an operation for completing the meshing between the internal spline 93 and the first external spline 74 can be started immediately, thereby shortening the waiting time (t6-t4).

[0143] As described above, in <1> this embodiment, the fork 50 has the fork base 51 and the movement restricting portions 501 and 502. The cylindrical fork base 51 is provided radially outward of the nut 42 and is movable axially relative to the nut 42. The movement restricting portions 501 and 502 are capable of restricting the axial movement of the fork base 51 relative to the nut 42. The electric actuator unit 20 has a spring 201 that is provided between the nut 42 and the fork base 51 and is capable of axially biasing the fork base 51 against the nut 42.

[0144] In this embodiment, while frictional force is generated when the dog clutch 90 and the first transmission part 70 are engaged, the movement restricting part 501 restricts the relative axial movement of the fork base 51 with respect to the nut 42. This allows torque from the rotary motor 30 to be transmitted to the dog clutch 90 via the nut 42, the movement restricting part 501, and the fork 50, without passing through the spring 201. This allows the rotary motor 30 to apply a thrust force greater than or equal to the frictional force to the dog clutch 90, thereby reducing the waiting time due to meshing impact. Furthermore, because the rotary motor 30 can apply a thrust force greater than or equal to the frictional force to the dog clutch 90, the dog clutch 90 can be reliably and quickly engaged with the first transmission part 70. This improves the responsiveness of the clutch device 10.

[0145] In addition, in this embodiment, when the engagement of the meshing clutch 90 is maintained, the power supplied to the rotary motor 30 is reduced, and the nut 42 is kept in contact with the movement restricting portion 502 by the biasing force of the spring 201, thereby improving the responsiveness of the meshing clutch 90 when it is disengaged.

[0146] Furthermore, in this embodiment, while a clearance is formed between the nut 42 and the movement restricting portion 501, the biasing force of the spring 201 acts on the dog clutch 90. Therefore, when the end of the internal teeth of the dog clutch 90 collides with the end of the external teeth of the first transmitting portion 70, the impact force can be prevented from being transmitted to the nut 42, the shaft 41, and the rotary motor 30, thereby protecting these components.

[0147] Furthermore, in the clutch device of Patent Document 1 (Korean Patent Specification No. 10-1666867), the frictional force generated when the internal teeth of the clutch sleeve mesh with the external teeth of the first transmission part causes the rotary motor to generate a high load, which may crush the standby spring and result in the spring compression (strength) design becoming invalid.

[0148] In contrast to this, in this embodiment, the nut 42 is configured to abut against the movement restricting portion 501, so that the spring 201 is not completely crushed, and it is easy to establish a spring compression (strength) design.

[0149] <2> In this embodiment, the nut 42 has a rotation restricting portion 400 that can restrict the relative rotation of the nut 42 with respect to the fork base portion 51 .

[0150] Therefore, the structure for preventing the nut 42 from rotating relative to the actuator case 21 can be realized without relying on the anti-rotation shaft 27 or the like, and the structure of the clutch device 10 can be simplified.

[0151] <3> <1-3> In this embodiment, the first transmitting part 70 has a first external spline 74 at its end on the second transmitting part 80 side. The second transmitting part 80 has a second external spline 83 at its end on the first transmitting part 70 side. The dog clutch 90 has a cylindrical clutch sleeve 91 that is provided radially outward from the end of the second transmitting part 80 on the first transmitting part 70 side and is movable axially relative to the second transmitting part 80. The clutch sleeve 91 has an internal spline 93 that meshes with the second external spline 83 and can mesh with the first external spline 74 when it moves axially relative to the second external spline 83 toward the first external spline 74. As described above, this embodiment includes a sleeve-type clutch in which the internal spline 93 of the sleeve-shaped clutch sleeve 91 meshes with the first external spline 74 of the first transmitting part 70.

[0152] The end of the first external spline 74 on the second external spline 83 side and the end of the internal spline 93 on the first external spline 74 side are formed with chamfered portions 741, 742, 931, and 932.

[0153] Therefore, even if the differential rotation between the first transmission part 70 and the second transmission part 80 is equal to or greater than a predetermined value, it is easy to insert the internal spline 93 between the first external spline 74, i.e., to mesh the internal spline 93 with the first external spline 74.

[0154] Furthermore, when the differential rotation between the first transmitting part 70 and the second transmitting part 80 is equal to or greater than a predetermined value, the internal spline 93 can be easily ratcheted with the first external spline 74. Therefore, when the differential rotation between the first transmitting part 70 and the second transmitting part 80 is equal to or greater than a predetermined value, the internal spline 93 can be prevented from meshing with the first external spline 74, thereby suppressing abnormal meshing, which is a phenomenon in which the internal spline 93 meshes with the first external spline 74 and causes a large shock when the differential rotation between the first transmitting part 70 and the second transmitting part 80 is equal to or greater than a predetermined value.

[0155] <4> In this embodiment, the nut 42 has a cylindrical inner nut portion 44 that moves axially relative to the shaft 41 when the shaft 41 rotates, and a cylindrical outer nut portion 45 that is provided radially outside the inner nut portion 44 so as not to rotate relative to the inner nut portion 44 and can move and slide axially relative to the fork base 51.

[0156] In this way, by dividing the nut 42 into the inner nut portion 44, which is a member having a "rotational-translation conversion function," and the outer nut portion 45, which is a member having a "sliding function relative to the fork 50," it can be manufactured easily and manufacturing costs can be reduced.

[0157] In this embodiment, the outer nut portion 45 is composed of a first outer nut portion 46, which is a member having a "rotation prevention function and a sliding function relative to the fork 50," and a second outer nut portion 47, which is a member having a "sliding function and a movement restriction function relative to the fork 50." This makes it easier to manufacture the nut 42, reducing manufacturing costs.

[0158] <5> In this embodiment, the rotary motor 30, the shaft 41, the nut 42, the fork base 51, and the spring 201 are arranged coaxially.

[0159] Therefore, the size of the clutch device 10 in the radial direction can be reduced.

[0160] For example, in the fork drive mechanism described in U.S. Patent No. 5,517,876, the rotary motor and rotary-translation unit are coaxially arranged, and the sleeve, spring, and fork are coaxially arranged, and are each mounted on a separate shaft. This may increase the radial size of the fork drive mechanism. Furthermore, the sleeve, spring, and fork are arranged in series in the axial direction. This may increase the axial size of the fork drive mechanism.

[0161] In contrast, in this embodiment, the rotary motor 30, the shaft 41 and nut 42 of the rotation-translation unit 40, the fork base 51, and the spring 201 are arranged coaxially, and the fork base 51 and the spring 201 are arranged radially outward of the rotation-translation unit 40. This allows the radial and axial sizes of the clutch device 10 to be reduced.

[0162] <1-1> This embodiment further includes an ECU 100 as a “controller.” The ECU 100 controls the supply of electricity to the rotary motor 30, thereby controlling the operation of the rotary motor 30 and the electric actuator unit 20.

[0163] In this embodiment, the ECU 100 controls the operation of the rotary motor 30 to move the dog clutch 90 to a position where the dog clutch 90 starts to come into contact with the first transmission part 70. The load of the spring 201 is set so that the dog clutch 90 and the first transmission part 70 can engage with each other under the load of the spring 201 after the dog clutch 90 and the first transmission part 70 start to come into contact with each other. This makes it possible to reduce the power supplied to the rotary motor 30 and the power consumption of the clutch device 10.

[0164] Furthermore, <1-2> In this embodiment, after the dog clutch 90 and the first transmission part 70 start to mesh, the ECU 100 controls the operation of the rotary motor 30 to bring the nut 42 into contact with the movement restricting part 501, and applies thrust from the rotary motor 30 to the dog clutch 90 without passing through the spring 201, thereby moving the dog clutch 90 relative to the first transmission part 70. Therefore, the dog clutch 90 and the first transmission part 70 can be reliably and quickly completed to mesh with each other.

[0165] Second Embodiment A clutch device according to a second embodiment is shown in Fig. 15. The second embodiment differs from the first embodiment in the configuration of the electric actuator unit 20 and the like.

[0166] [3] In this embodiment, the electric actuator unit 20 further includes a return spring 202. The return spring 202 is a coil spring formed by winding a metal wire, for example, in a coil shape.

[0167] In this embodiment, the fork 50 has a fork extension tubular portion 534. The fork extension tubular portion 534 is formed integrally with the fork base 51 from the outer edge of the end face of the fork base 51 opposite the rotary motor 30, and is cylindrically extending.

[0168] The return spring 202 is provided radially outside the shaft 41, with one axial end abutting the end face of the fork base 51 opposite the rotary motor 30, and the other axial end abutting the inner wall of the actuator case 21. Here, one axial end of the return spring 202 is located radially inside the fork extension tubular portion 534. This makes it possible to prevent one axial end of the return spring 202 from shifting relative to the end face of the fork base 51.

[0169] The return spring 202 has a force that stretches in the axial direction. Therefore, when the rotary motor 30 is not energized, the fork 50 is urged toward the rotary motor 30 by the urging force of the return spring 202. This presses the dog clutch 90 against the second annular plate portion 82.

[0170] The biasing force of the return spring 202 is set to be smaller than the biasing force of the spring 201 .

[0171] In this embodiment, the return spring 202 allows the dog clutch 90 to be in a state of not engaging with the first transmission part 70 when the rotary electric motor 30 is not energized. Therefore, when the clutch device 10 is applied to a vehicle 1 in which the period during which the transmission of torque between the first transmission part 70 and the second transmission part 80 is interrupted is long, the power consumption of the clutch device 10 can be reduced.

[0172] Furthermore, for example, if the rotating motor 30 fails while the vehicle 1 is running, a fail-safe measure can be taken by stopping the supply of electricity to the rotating motor 30, thereby disengaging the meshing clutch 90 from the first transmission unit 70 and cutting off the transmission of torque between the first transmission unit 70 and the second transmission unit 80.

[0173] (Third Embodiment) A clutch device according to a third embodiment is shown in Fig. 16. The third embodiment differs from the first embodiment in the configuration of the electric actuator unit 20 and the like.

[0174] [3] In this embodiment, the electric actuator unit 20 further includes a return spring 203. The return spring 203 is, for example, a coil spring formed by winding a metal wire into a coil.

[0175] In this embodiment, the bearing portion 22 has a bearing portion step surface 221. The bearing portion step surface 221 is formed in an annular, flat shape on the outer wall of the bearing portion 22 so as to face the washer 57 of the fork 50.

[0176] The return spring 203 is provided radially outside the shaft 41 so that one axial end abuts against the bearing portion stepped surface 221 and the other axial end abuts against the washer 57 .

[0177] The return spring 203 has a force that stretches in the axial direction. Therefore, when the rotary motor 30 is not energized, the fork 50 is urged in the opposite direction from the rotary motor 30 by the urging force of the return spring 203. This presses the dog clutch 90 against the first annular plate portion 73.

[0178] The biasing force of the return spring 203 is set to be smaller than the biasing force of the spring 201 .

[0179] In this embodiment, the return spring 203 allows the dog clutch 90 to be in a state of being engaged with the first transmission part 70 when the rotary electric motor 30 is not energized. Therefore, when the clutch device 10 is applied to a vehicle 1 in which the allowable period for torque transmission between the first transmission part 70 and the second transmission part 80 is long, the power consumption of the clutch device 10 can be reduced.

[0180] Furthermore, for example, if the rotating motor 30 fails while the vehicle 1 is running, a fail-safe response can be taken, such as stopping the supply of electricity to the rotating motor 30, thereby engaging the meshing clutch 90 with the first transmission unit 70 and allowing torque transmission between the first transmission unit 70 and the second transmission unit 80.

[0181] (Fourth embodiment) A clutch device according to a fourth embodiment is shown in Fig. 17. The fourth embodiment differs from the first embodiment in the configuration of the clutch portion 60 and the like.

[0182] [7] In this embodiment, the dog clutch 90 has a detent mechanism 95 .

[0183] 18 , the detent mechanism 95 has a detent hole 96, a detent spring 97, a detent ball 98, a first detent recess 991, and a second detent recess 992. The detent hole 96 is recessed radially outward from the inner circumferential wall of the sleeve body 92. The detent spring 97 is a coil spring formed by winding a metal wire into a coil, for example. The detent spring 97 is accommodated in the detent hole 96 so that one axial end of the detent spring 97 abuts against the bottom surface of the detent hole 96.

[0184] The detent ball 98 is provided in the opening of the detent hole 96 so as to abut against the other axial end of the detent spring 97. The first detent recess 991 and the second detent recess 992 are provided, for example, in the second external spline 83. The first detent recess 991 and the second detent recess 992 are each formed so as to be recessed from the outer wall of one of the second external splines 83 radially inward of the second transmission part body 81.

[0185] The first detent recess 991 is formed on the axis of the detent hole 96 when the sleeve body 92 is in contact with the second annular plate 82 (see FIG. 18 ). The second detent recess 992 is formed on the axis of the detent hole 96 when the sleeve body 92 is in contact with the first annular plate 73 (see FIG. 20 ).

[0186] The first detent recess 991 and the second detent recess 992 are formed to allow the detent ball 98 to fit in. When the detent ball 98 fits in the first detent recess 991 or the second detent recess 992, a portion of the detent ball 98 is positioned inside the opening of the detent hole 96 (see FIGS. 18 and 20 ).

[0187] On the other hand, when the detent ball 98 is not inserted into the first detent recess 991 or the second detent recess 992, the entire detent ball 98 is positioned inside the opening of the detent hole 96 (see FIG. 19).

[0188] With the above configuration, in the initial state in which the dog clutch 90 abuts against the second annular plate portion 82, the detent ball 98 enters the first detent recess 991, and the axial position of the dog clutch 90 relative to the second transmission portion 80 is maintained (see FIG. 18 ). As a result, even when the power supply to the rotary motor 30 is stopped, the transmission of torque between the first transmission portion 70 and the second transmission portion 80 can be maintained in a blocked state.

[0189] 18 , when the rotary motor 30 is energized and the fork 50 translates the dog clutch 90 toward the first transmitting part 70, the detent ball 98 comes out of the first detent recess 991 and is positioned between the first detent recess 991 and the second detent recess 992 (see FIG. 19 ). In this state, even if the energization of the rotary motor 30 is stopped, the axial position of the dog clutch 90 relative to the second transmitting part 80 is not maintained.

[0190] 19 , when the fork 50 further translates the dog clutch 90 toward the first transmission part 70, the dog clutch 90 comes into contact with the first annular plate part 73, the detent ball 98 enters the second detent recess 992, and the axial position of the dog clutch 90 relative to the second transmission part 80 is maintained (see FIG. 20 ). As a result, even when the power supply to the rotary motor 30 is stopped, the state in which torque transmission between the first transmission part 70 and the second transmission part 80 is permitted can be maintained.

[0191] In this embodiment, the detent mechanism 95 maintains the axial position of the dog clutch 90 relative to the second transmission part 80, thereby making it possible to appropriately stop the supply of electricity to the rotary motor 30. This makes it possible to reduce the power consumption of the clutch device 10.

[0192] While the above-described embodiment shows an example in which the nut, fork base, inner nut portion, and outer nut portion are formed in a cylindrical shape, in other embodiments, the nut, fork base, inner nut portion, and outer nut portion may be formed in, for example, an annular shape.

[0193] In the above-described embodiment, the chamfered portions formed on the end of the first external spline facing the second external spline and the end of the internal spline facing the first external spline are flat and inclined at approximately 45 degrees with respect to a straight line along the extension direction of the first external spline or the internal spline. However, in other embodiments, the chamfered portions may be flat and inclined at an angle other than 45 degrees with respect to the straight line, or may be curved. In other embodiments, the end of the first external spline facing the second external spline and the end of the internal spline facing the first external spline may not be chamfered.

[0194] Furthermore, in the above-described embodiment, an example has been shown in which a sleeve-type clutch is applied in which the internal spline 93 of the sleeve-shaped clutch sleeve 91 meshes with the first external spline 74 of the first transmitting part 70. However, in other embodiments, for example, a face-type clutch may be applied in which a drive dog provided at the tip of the dog clutch 90 and a driven dog provided on the first transmitting part 70 face each other in the axial direction and mesh with each other. Even when a face-type clutch is applied, the same effects as when a sleeve-type clutch is applied can be achieved.

[0195] In addition, in the above-described embodiment, an example was shown in which the nut is configured by the inner nut portion and the outer nut portion which are separate bodies. However, in other embodiments, the inner nut portion and the outer nut portion may be integrally formed to form a nut.

[0196] In the above-described embodiment, an example has been shown in which the differential shaft 11 is connected to the first transmission unit 70 and the wheel shafts 12 are connected to the second transmission unit 80. However, in other embodiments, the wheel shafts 12 may be connected to the first transmission unit 70 and the differential shaft 11 may be connected to the second transmission unit 80.

[0197] In the above embodiment, the clutch device 10 is provided outside the axle case 16. However, in other embodiments, the clutch device 10 may be provided inside the axle case 16.

[0198] In the above-described embodiment, the clutch device 10 is provided between the differential shaft 11 and the wheel shafts 12 to control the transmission of torque between the differential shaft 11 and the wheel shafts 12. However, in another embodiment, the clutch device 10 may be applied by dividing the first gear shaft 3 into two shafts between the motor generator 2 and the first small-diameter gear 5, with one shaft connected to the first transmission section 70 and the other shaft connected to the second transmission section 80. In this case, the clutch device 10 can control the transmission of torque between the motor generator 2 and the first small-diameter gear 5.

[0199] In another embodiment, for example, the second gear shaft 4 may be divided into two parts between the first large diameter gear 6 and the second small diameter gear 7, with one part connected to the first transmission part 70 and the other part connected to the second transmission part 80, and the clutch device 10 may be applied in this manner. In this case, the clutch device 10 can control the transmission of torque between the first large diameter gear 6 and the second small diameter gear 7.

[0200] In addition, in the above-described embodiment, an example has been shown in which the clutch device is used to control the transmission of torque between the motor generator and the rear wheels of the vehicle. However, in other embodiments, the clutch device may be used to control the transmission of torque between the motor generator and the front wheels of the vehicle.

[0201] Furthermore, the present disclosure is not limited to electric vehicles, but can also be applied to vehicles that run on drive torque from an internal combustion engine, hybrid vehicles, and the like.

[0202] As such, the present disclosure is not limited to the above-described embodiments, and can be implemented in various forms without departing from the spirit of the present disclosure.

[0203] The present disclosure has been described based on the embodiments. However, the present disclosure is not limited to the embodiments and structures. The present disclosure also encompasses various modifications and variations within the scope of equivalents. Furthermore, various combinations and forms, as well as other combinations and forms including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

Claims

1. an electric actuator unit (20) having a rotary motor (30), a rotary translation unit (40) capable of converting rotary motion caused by torque from the rotary motor into translation motion, and a fork (50) capable of translation by the translation motion of the rotary translation unit; a clutch unit (60) having a first transmission unit (70), a second transmission unit (80) that is rotatable relative to the first transmission unit, and a meshing clutch (90) that translates with the translation of the fork and meshes with the first transmission unit to allow transmission of torque between the first transmission unit and the second transmission unit; a control unit (100) capable of controlling the operation of the rotary motor and the electric actuator unit by controlling the supply of electricity to the rotary motor; the rotation-translation unit includes a shaft (41) that rotates when torque is input from the rotary motor, and an annular or cylindrical nut (42) that is provided radially outside the shaft and moves axially relative to the shaft by translation when the shaft rotates; The fork has an annular or cylindrical fork base (51) that is provided radially outside the nut and is movable in the axial direction relative to the nut, and a movement restricting portion (501, 502) that restricts the axial movement of the fork base relative to the nut, The electric actuator unit has a spring (201) that is provided between the nut and the fork base and is capable of axially biasing the fork base against the nut, The control unit can control the operation of the rotary motor to move the dog clutch to a position where the dog clutch starts to contact the first transmission unit, a load of the spring is set so that the dog clutch and the first transmission part can engage with each other under the load of the spring after the dog clutch and the first transmission part start to come into contact with each other, The movement restricting portion is a clutch device that restricts axial movement of the fork base relative to the nut by abutting against the nut.

2. A clutch device as described in Claim 1, wherein a portion (501) of the movement regulating portion is provided radially outside the spring.

3. The rotary translation part has a shaft (41) that rotates by torque from the rotary motor, 3. The clutch device according to claim 1, wherein the spring is provided coaxially with the shaft.

4. The clutch device according to claim 1 or 2, wherein the control unit controls the operation of the rotary motor after the meshing clutch and the first transmission part start to mesh, thereby causing the nut to abut against the movement restricting part (501), applying thrust from the rotary motor to the meshing clutch without passing through the spring, and moving the meshing clutch relative to the first transmission part.

5. The first transmission part has a first external spline (74) at an end part on the second transmission part side, The second transmission part has a second external spline (83) at an end part on the first transmission part side, The dog clutch has a cylindrical clutch sleeve (91) that is provided radially outward of an end of the second transmission part on the side of the first transmission part and is movable axially relative to the second transmission part, 3. The clutch device according to claim 1, wherein the clutch sleeve has an internal spline (93) that is capable of meshing with the first external spline when the clutch sleeve moves axially relative to the second external spline toward the first external spline while meshing with the second external spline.