Electric friction clutch device

Abstract

To sufficiently and reliably maintain an amount of expansion in the axial dimension of a cam device, and to enable speedy switching to a cur-off mode when an electric actuators fails, for example.SOLUTION: A cam device 5 includes: a drive cam 37 having a cam surface 40 on an axial one side surface and supported such that the drive cam is rotatable with respect to a fixed part, which does not rotate even during use, and is axially non-displaceable; and a holder 38 supported in such a manner that it is axially displaceable with respect to the fixed part and is unrotatable; a plurality of rotors 39 having a rotation surface 69 which makes rolling contact with the cam surface 40 and held in the holder 38; and a twist coil spring 80 which spans between the drive cam 37 and the fixed part, and which applies to the drive cam 37 a resilience in a direction of rotating the drive cam 37 in a direction of decreasing a gap with the holder 38.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to an electric friction clutch device that switches between a connected mode in which a first member and a second member rotate integrally, and a disconnected mode in which the first member and the second member rotate relative to each other. [Background technology]

[0002] In rotating machinery such as automobiles and machine tools, a transmission is provided between a power source, such as an engine or an electric motor, and a driven object to efficiently utilize the output of the power source. When a gear-type transmission with multiple stages is used as such a transmission, a clutch device is installed between the power source and the transmission to switch between a locked state in which the output torque of the power source can be transmitted to the transmission and an unlocked state in which it cannot be transmitted. Examples of such clutch devices include a friction clutch that transmits power through friction between a pair of opposing friction surfaces, and a dog clutch that transmits power through meshing pawls.

[0003] The friction clutch can switch between a connected mode in which torque can be transmitted and a disconnected mode in which torque cannot be transmitted, regardless of the phase difference or rotational speed difference between a pair of opposing engaging members.

[0004] 35 shows a clutch device 100 described in WO 2008 / 096438. The clutch device 100 is disposed between an input member (rear wheel output shaft) 101 and an output member (sprocket) 102, and switches between a connected mode in which torque is transmitted between the input member 101 and the output member 102, and a disconnected mode in which torque is not transmitted between the input member 101 and the output member 102. The clutch device 100 includes a first member 103, a second member 104, a friction engagement portion 105, a cam device 106, an electric actuator 107, a pressing member 108, a rolling bearing 109, and an elastic member 110.

[0005] The first member 103 is coupled and fixed to the input member 101 and rotates integrally with the input member 101. The first member 103 has a small-diameter cylindrical portion 103a fitted and fixed to the outside of the input member 101, a side plate portion 103b bent radially outward from an end portion on one axial side (the left side in FIG. 35) of the small-diameter cylindrical portion 103a, and a large-diameter cylindrical portion 103c protruding radially outward from a radially intermediate portion of the other axial side surface (the right side surface in FIG. 35) of the side plate portion 103b. That is, the first member 103 has a substantially F-shaped cross section.

[0006] The second member 104 is coupled and fixed to the output member 102, and rotates integrally with the output member 102. The second member 104 has a circular ring portion 104a that is fitted and fixed to the outside of the output member 102, and a cylindrical portion 104b that is bent from the radially outer end of the circular ring portion 104a toward the other axial side.

[0007] The friction engagement portion 105 includes a plurality of first friction plates 105a and a plurality of second friction plates 105b stacked alternately in the axial direction. Each first friction plate 105a is fitted externally to the large-diameter cylindrical portion 103c of the first member 103 so as to be displaceable in the axial direction but not to rotate relative thereto. Each second friction plate 105b is fitted internally to the cylindrical portion 104b of the second member so as to be displaceable in the axial direction but not to rotate relative thereto.

[0008] The cam device 106 includes a drive cam 106a, a cam plate 106b, and a plurality of balls 106c.

[0009] The drive cam 106a has a drive-side cam surface 106a1 on the other axial side surface and a gear portion 106a2 on the outer circumferential surface. The drive cam 106a is disposed around the input member 101 so as to be capable of relative rotation with respect to the input member 101 and displacement in the axial direction.

[0010] Cam plate 106b has a fixed cam surface 106b1 on one axial side surface. Cam plate 106b is disposed around input member 101 so as to be capable of rotating relative to input member 101 but not capable of moving in the axial direction.

[0011] Each ball 106c is held between a driving side cam surface 106a1 and a fixed side cam surface 106b1 in a rollable manner.

[0012] The electric actuator 107 rotates and drives the drive cam 106a of the cam device 106. The electric actuator 107 has an electric motor 107a and a reducer 107b that increases the output torque of the electric motor 107a and transmits it to the drive cam 106a. For this purpose, an output gear 107b1 of the reducer 107b is meshed with a gear portion 106a2 provided on the outer circumferential surface of the drive cam 106a.

[0013] The pressing member 108 is disposed opposite to the other axial side of the friction plate located furthest from the other axial side among the plurality of first friction plates 105a and second friction plates 105b, and is supported so as to be movable toward and away from the friction plate located furthest from the other axial side. The pressing member 108 is fitted around the periphery of the input member 101 so as to be movable in the axial direction relative to the input member 101.

[0014] The rolling bearing 109 is disposed between the driving cam 106a and the pressing member 108.

[0015] The elastic member 110 is sandwiched between the first member 103 and the pressing member 108 in an elastically compressed state, and elastically biases the pressing member 108 toward the other axial direction. The elastic member 110 is made of a compression coil spring.

[0016] When switching the clutch device 100 to the connection mode, the electric actuator 107 rotates the drive cam 106a, and the ball 106c is positioned between the tip surface of the convex portion of the drive-side cam surface 106a1 and the tip surface of the convex portion of the fixed-side cam surface 106b1, thereby widening the gap between the drive cam 106a and the cam plate 106b and pressing the pressing member 108 toward one side in the axial direction. As a result, the first friction plate 105a and the second friction plate 105b are pressed against each other, connecting the friction engagement portion 105 and causing the first member 103 and the second member 104 to rotate integrally.

[0017] When the clutch device 100 is switched to the disengagement mode, the electric actuator 107 rotates the drive cam 106a, and the ball 106c is positioned between the bottom of the recess in the drive-side cam surface 106a1 and the bottom of the recess in the fixed-side cam surface 106b1. The elastic force of the elastic member 110, which tries to return to its original position, presses the pressing member 108 toward the other axial direction, thereby reducing the gap between the drive cam 106a and the cam plate 106b. As a result, the force pressing the first friction plate 105a and the second friction plate 105b against each other is released, the friction engagement portion 105 is disengaged, and the first member 103 and the second member 104 begin to rotate relative to each other. [Prior art documents] [Patent documents]

[0018] [Patent Document 1] International Publication No. 2008 / 096438 Brochure Summary of the Invention [Problem to be solved by the invention]

[0019] In the clutch device 100 described in International Publication No. 2008 / 096438, slippage occurs between the driving-side cam surface 106a1 and / or the fixed-side cam surface 106b1 and the rolling surfaces of the balls 106c, which can cause variations in the amount of lift of the balls 106c from the bottom of the recesses of the driving-side cam surface 106a1 and / or the fixed-side cam surface 106b1. Such variations can result in an insufficient amount of axial displacement of the pressing member 108. As a result, when the clutch device 100 is switched to the engagement mode, the fastening force of the frictional engagement portion 105 cannot be sufficiently secured. When the clutch device 100 is switched to the disengagement mode, the first friction plate 105a and the second friction plate 105b cannot be sufficiently separated, resulting in drag.

[0020] Furthermore, to ensure safety, if the electric actuator 107 should fail, it is desirable to quickly switch the clutch device 100 to the disengagement mode regardless of the mode of the clutch device 100 at the time the failure occurred.

[0021] The present disclosure aims to realize a structure for an electric friction clutch that can sufficiently and reliably ensure the amount of expansion and contraction of the axial dimension of the cam device, and that can quickly switch to a disconnection mode in the event of a failure of the electric actuator, etc. [Means for solving the problem]

[0022] An electric friction clutch device according to a first aspect of the present disclosure includes a first member, a second member, a friction engagement portion, a cam device, an electric actuator, a pressing member, a rolling bearing, and an elastic member.

[0023] The second member is supported coaxially with the first member and rotatable relative to the first member.

[0024] The friction engagement portion has at least one, and preferably a plurality of, first and second friction plates that are supported to allow relative displacement in the axial direction.

[0025] The cam device includes a drive cam, a holder, a plurality of rolling elements, and a torsion coil spring.

[0026] The drive cam has a cam surface on one side surface in the axial direction, and is supported so as to be rotatable relative to a fixed portion that does not rotate even during use, but so as not to be displaceable in the axial direction.

[0027] The holder is supported so as to be movable axially relative to the fixed member but not to be rotatable.

[0028] The rolling element has a rolling surface that comes into rolling contact with the cam surface, and is held by the holder.

[0029] The torsion coil spring is stretched between the drive cam and the fixed portion, and applies a resilient force to the drive cam in a direction that rotates the drive cam in a direction that reduces the gap between the drive cam and the holder.

[0030] The electric actuator rotates the drive cam.

[0031] The pressing member is disposed opposite the other axial side surface of the friction plate that is located furthest in the axial direction out of the first friction plate and the second friction plate, and is supported so as to be movable toward and away from the friction plate located furthest in the axial direction.

[0032] The rolling bearing is disposed between the holder and the pressing member.

[0033] The elastic member elastically biases the pressing member toward the other axial direction.

[0034] The electric friction clutch device of the first aspect of the present disclosure switches to a connection mode in which the first member and the second member rotate as a unit by displacing the holder in a direction that increases the distance from the drive cam by rotating the drive cam with the electric actuator, thereby pressing the first friction plate and the second friction plate against each other, and switches to a disconnection mode in which the first member and the second member rotate relative to each other by displacing the holder in a direction that decreases the distance from the drive cam, thereby releasing the force pressing the first friction plate and the second friction plate against each other.

[0035] In the electric friction clutch device of the second aspect of the present disclosure, in the electric friction clutch device of the first aspect of the present disclosure, the torsion coil spring has a pair of arm portions and an elastic deformation portion connecting the pair of arm portions, one of the pair of arm portions is engaged with the drive cam, and the other arm portion is engaged with the fixed portion.

[0036] In the electric friction clutch device of the third aspect of the present disclosure, the electric friction clutch device of the second aspect of the present disclosure has a cam side locking hole that opens to at least the other axial side surface, and the tip end of the arm portion is locked (inserted) into the cam side locking hole.

[0037] In a fourth aspect of the electric friction clutch device of the present disclosure, in the electric friction clutch device of the second aspect of the present disclosure, the electric actuator has an electric motor and a drive gear that is rotationally driven by the electric motor directly or via a reducer, and the drive cam includes a main body having the cam surface on one axial side surface, and a protrusion that protrudes radially outward from one circumferential position of the main body and has a gear portion that meshes with the drive gear on its radially outer surface, and in this case, the one arm portion is elastically pressed against an end face on one circumferential side of the protrusion.

[0038] In a fifth aspect of the electric friction clutch device of the present disclosure, in the electric friction clutch device of any one of the second to fourth aspects of the present disclosure, the fixed portion includes a support member having a fixed-side locking hole penetrating in the axial direction, and the support member is positioned relative to a portion of the fixed portion other than the support member by a positioning pin inserted into the fixed-side locking hole. In this case, a tip end of the other arm portion is locked to the positioning pin.

[0039] In a sixth aspect of the electric friction clutch device of the present disclosure, in the electric friction clutch device of any one of the second to fourth aspects of the present disclosure, the fixed portion includes a support member having a fixed-side locking hole penetrating in the axial direction, and the tip end of the other arm portion is inserted into the fixed-side locking hole and a tubular member. In this case, the tubular member positions the fixed portion relative to the portion other than the support member.

[0040] An electric friction clutch device according to a seventh aspect of the present disclosure is the electric friction clutch device according to any one of the first to sixth aspects of the present disclosure, The rolling element has a cylindrical shape, and The cam device includes a plurality of support shafts, each of which has its end portion supported on both axial sides in the holder, and a plurality of rollers, each of which is freely rollable, arranged between the inner circumferential surface of the rolling element and the outer circumferential surface of the support shaft.

[0041] In an electric friction clutch device of an eighth aspect of the present disclosure, in the electric friction clutch device of the seventh aspect of the present disclosure, the cam device is provided with a retaining member that prevents the support shaft from being displaced in the axial direction of the support shaft relative to the holder.

[0042] In a ninth aspect of the present disclosure, in the electric friction clutch device of any one of the first to eighth aspects of the present disclosure, the first member has a first cylindrical portion, and the first friction plate is supported on an outer peripheral surface of the first cylindrical portion. In this case, the elastic member, a part of the pressing member, and the rolling bearing are disposed radially inside the first cylindrical portion.

[0043] In an electric friction clutch device according to a tenth aspect of the present disclosure, in the electric friction clutch device according to any one of the first to ninth aspects of the present disclosure, the first member comprises a flange member having a first cylindrical portion and a circular ring portion bent radially inward from one axial end of the first cylindrical portion, and a shaft body coupled and fixed to the inner circumferential surface of the circular ring portion. In this case, the first friction plate is supported on the outer circumferential surface of the first cylindrical portion.

[0044] An electric friction clutch device of an eleventh aspect of the present disclosure is the electric friction clutch device of the tenth aspect of the present disclosure, wherein the flange member is a pressed product and the shaft body is a forged product.

[0045] In an electric friction clutch device according to a twelfth aspect of the present disclosure, in the electric friction clutch device according to any one of the ninth to eleventh aspects of the present disclosure, the first member includes a snap ring engaged with an outer peripheral surface of the first cylindrical portion. In this case, the first friction plate is supported on the outer peripheral surface of the first cylindrical portion so as to be able to move axially, and the snap ring prevents the first friction plate from moving axially to one side.

[0046] An electric friction clutch device according to a thirteenth aspect of the present disclosure is the electric friction clutch device according to any one of the first to twelfth aspects of the present disclosure, wherein the elastic member is formed of a disc spring.

[0047] In an electric friction clutch device of a fourteenth aspect of the present disclosure, in the electric friction clutch device of any one of the first to thirteenth aspects of the present disclosure, the drive cam and / or the holder are made of sintered metal. [Effects of the Invention]

[0048] According to the electric friction clutch device of the present disclosure, the amount of expansion / contraction of the axial dimension of the cam device can be sufficiently and reliably ensured, and in the event of a failure of the electric actuator, the device can be quickly switched to the disconnection mode. [Brief explanation of the drawings]

[0049] [Figure 1] FIG. 1 is an end view of an electric friction clutch device according to a first example of an embodiment of the present disclosure, as viewed from one axial side. [Figure 2] FIG. 2 is an end view of the electric friction clutch device of the first example, as viewed from the other axial side. [Figure 3] FIG. 3 is a cross-sectional view taken along line AA in FIG. 1, with the second member omitted. [Figure 4] FIG. 4 is an exploded perspective view showing the electric friction clutch device of the first example, with the torsion coil spring omitted. [Figure 5] FIG. 5 is a perspective view of the electric friction clutch device of the first example, seen from one axial side, with the second member omitted. [Figure 6] FIG. 6 is a perspective view of the electric friction clutch device of the first example, seen from the other axial side, with the second member omitted. [Figure 7] FIG. 7 is a perspective view showing the first member. [Figure 8] FIG. 8 is a cross-sectional view showing the first member. [Figure 9] FIG. 9 is a perspective view showing the support member. [Figure 10] FIG. 10 is a side view showing the cam device in a state where the distance between the drive cam and the holder is shortened. [Figure 11] FIG. 11 is a side view showing the cam device in a state where the distance between the drive cam and the holder is widened. [Figure 12] FIG. 12 is a perspective view showing the drive cam. [Figure 13] FIG. 13 is a perspective view showing the drive cam and the worm. [Figure 14] FIG. 14 is a perspective view showing the holder and the rolling element in an assembled state. [Figure 15] FIG. 15 is an end view of the holder and rolling elements assembled together, as viewed from the other axial side. [Figure 16] FIG. 16 is a cross-sectional view taken along the line BB in FIG. [Figure 17] FIG. 17 is an exploded perspective view showing the assembly of the rolling elements to the holder. [Figure 18] FIG. 18 is an end view showing the torsion coil spring. [Figure 19] FIG. 19 is an end view showing the frictional engagement portion. [Figure 20] FIG. 20 is a cross-sectional view taken along CC in FIG. [Figure 21] FIG. 21 is an exploded perspective view showing the frictional engagement portion. [Figure 22] FIG. 22 is a perspective view showing another example of the support shaft. [Figure 23] FIG. 23 is a diagram showing the relationship between the rotation angle of the drive cam and the amount of axial displacement in the modified example of the first example. [Figure 24] FIG. 24 is a diagram corresponding to FIG. 6 and relating to a second example of an embodiment of the present disclosure. [Figure 25] FIG. 25 is a diagram corresponding to FIG. 6 and relating to a third example of an embodiment of the present disclosure. [Figure 26]FIG. 26 is a diagram corresponding to FIG. 6 and relating to a fourth example of an embodiment of the present disclosure. [Figure 27] FIG. 27 is a diagram corresponding to FIG. 6 and relating to a fifth example of an embodiment of the present disclosure. [Figure 28] FIG. 28 is an end view showing a torsion coil spring that constitutes the electric friction clutch device of the fifth example. [Figure 29] FIG. 29 is a diagram corresponding to FIG. 6 and relating to a sixth example of an embodiment of the present disclosure. [Figure 30] FIG. 30 is an end view showing the torsion coil spring and the cylindrical member that constitute the electric friction clutch device of the sixth embodiment. [Figure 31] FIG. 31 is a view corresponding to an enlarged view of a portion D in FIG. 3, illustrating an electric friction clutch device according to a seventh example of an embodiment of the present disclosure. [Figure 32] FIG. 32 is a view showing an end plate of the electric friction clutch device of the seventh example. [Figure 33] FIG. 33 is a view corresponding to an enlarged view of a portion E in FIG. 3, illustrating an electric friction clutch device according to an eighth example of an embodiment of the present disclosure. [Figure 34] FIG. 34 shows the nut of the electric friction clutch device of the eighth example, where (A) is a perspective view seen from one axial side, and (B) is a perspective view seen from the other axial side. [Figure 35] FIG. 35 is a cross-sectional view showing an example of a clutch device with a conventional structure. DETAILED DESCRIPTION OF THE INVENTION

[0050] [Example 1] 1 to 21 show a first example of an embodiment of the present disclosure. The electric friction clutch device 1 of this example includes a first member 2, a second member 3, a friction engagement portion 4, a cam device 5, an electric actuator 6, a pressing member 7, a rolling bearing 8, and an elastic member 9.

[0051] The electric friction clutch device 1 is disposed, for example, in a portion of the drive system of an automobile between a drive source such as an electric motor or an engine and a transmission, or between the transmission and a differential. However, the electric friction clutch device of the present disclosure can be disposed between a pair of rotating members or between a rotating member and a fixed member in various mechanical devices, regardless of the drive system of the automobile.

[0052] In the following description, unless otherwise specified, the axial direction, radial direction, and circumferential direction refer to the axial direction, radial direction, and circumferential direction of the first member 2. One axial side refers to the left side in Fig. 3, and the other axial side refers to the right side in Fig. 3.

[0053] The first member 2 is rotatably supported by a support member 10, which is a part of a fixed portion that does not rotate even during use. The first member 2 is connected to a first rotating member 72 (see FIG. 4), such as the output shaft of a drive source or the output shaft of a transmission, so as to be able to transmit torque.

[0054] As shown in FIG. 9, the support member 10 includes a fixed cylindrical portion 11 and a flange portion 12 bent radially outward from the other axial end of the fixed cylindrical portion 11.

[0055] The fixed cylinder portion 11 has a male spline portion 13 on the outer peripheral surface of one end portion in the axial direction.

[0056] The flange portion 12 has a fixed-side locking hole 70 that penetrates in the axial direction at one location in the circumferential direction.

[0057] The support member 10 is supported and fixed to the fixed part other than the support member 10, such as the housing, by a positioning pin (not shown) engaged in the fixed side engagement hole 70 of the flange portion 12, and does not rotate or displace during use.

[0058] As shown in FIGS. 7 and 8, the first member 2 includes a flange member 14 and a shaft body 15.

[0059] The flange member 14 has a first cylindrical portion 16 and a circular ring portion 17 bent radially inward from one axial end of the first cylindrical portion 16. In this example, the flange member 14 is made by pressing a metal plate having sufficient strength and rigidity, such as a steel plate, and then nitriding the surface.

[0060] The first cylindrical portion 16 has an inner diameter side concave-convex portion 18 on its outer circumferential surface, in which concave portions and convex portions are alternately arranged in the circumferential direction.

[0061] Shaft body 15 is joined and fixed to the inner circumferential surface of circular ring portion 17 of flange member 14. In this example, shaft body 15 has a stepped cylindrical shape. Specifically, shaft body 15 is constructed by connecting a large-diameter cylindrical portion 19 on one axial side and a small-diameter cylindrical portion 20 on the other axial side by a hollow circular plate-like side plate portion 21. In this example, shaft body 15 is made by forging a hard metal material such as medium carbon steel and then nitriding the surface.

[0062] The small-diameter cylindrical portion 20 has a locking groove 22 formed around the entire circumference on the outer circumferential surface of the other axial side portion, and has a female spline portion 71 on the inner circumferential surface of the other axial end portion.

[0063] In this example, first member 2 is constructed by fitting one axial end of large-diameter cylindrical portion 19 of shaft body 15 into circular ring portion 17 of flange member 14, and then joining and fixing flange member 14 and shaft body 15 together by welding. First member 2 is connected to first rotating member 72 (see Figure 4) so as to be able to transmit torque by spline-engaging male spline portion 73 of first rotating member 72 with female spline portion 71.

[0064] The first member 2 is rotatably supported relative to the support member 10 by a radial rolling bearing 23 .

[0065] The radial rolling bearing 23 includes an inner ring 24, an outer ring 25, and a plurality of rolling elements 26 disposed between the inner ring 24 and the outer ring 25 so as to be freely rollable.

[0066] The inner ring 24 is fitted onto one axial side portion of the small diameter cylindrical portion 20 and is axially sandwiched between the other axial side surface of the side plate portion 21 and a retaining ring 27 engaged in the engaging groove 22.

[0067] The outer ring 25 is fitted into the other axial side portion of the fixed cylindrical portion 11 and is provided on the inner surface of the axial middle portion of the fixed cylindrical portion 11, and is axially sandwiched between a step surface 28 facing the other axial side and a retaining ring 29 engaged with the inner surface of the end portion on the other axial side of the fixed cylindrical portion 11.

[0068] The radial rolling bearing 23 in this example is a single-row angular contact ball bearing that uses balls as rolling elements 26 and has a contact angle. However, the radial rolling bearing for rotatably supporting the first member relative to the fixed member is not particularly limited as long as it can support radial and thrust loads, and can also be a single-row deep groove ball bearing or a tapered roller bearing.

[0069] The second member 3 is supported coaxially with the first member 2 and capable of relative rotation with respect to the first member 2. The second member 3 is connected to a second rotating member (not shown) such as an input shaft of a transmission or an input shaft of a differential device so as to be capable of transmitting torque. In this example, the second member 3 has a second tubular portion 30.

[0070] The second cylindrical portion 30 has an outer diameter side concave-convex portion 31 on its inner circumferential surface, in which concave portions and convex portions are alternately arranged in the circumferential direction.

[0071] The friction engagement portion 4 has at least one, and preferably multiple, first friction plates 32 and second friction plates 33 that are supported so as to be capable of relative axial displacement. In this example, the friction engagement portion 4 is configured by alternately stacking six first friction plates 32 and five second friction plates 33.

[0072] Each of the first friction plates 32 is configured in a substantially hollow circular plate shape. Each of the first friction plates 32 has an outer diameter side uneven portion 34 on its inner circumferential surface, where concave and convex portions are alternately arranged in the circumferential direction. Each of the first friction plates 32 is supported with respect to the first cylindrical portion 16 so as to be able to move axially but not to rotate relative to the first cylindrical portion 16 by engaging the outer diameter side uneven portion 34 with the inner diameter side uneven portion 18 of the first member 2.

[0073] The first friction plate 32 located furthest to one side in the axial direction among the six first friction plates 32 is prevented from displacing to one side in the axial direction by a retaining ring 35 engaged with the outer peripheral surface of the one side axial portion of the first cylindrical portion 16.

[0074] Each second friction plate 33 is configured in a substantially hollow circular plate shape. Each second friction plate 33 has an inner diameter side uneven portion 36 on its outer circumferential surface, where concave and convex portions are alternately arranged in the circumferential direction. Each second friction plate 33 is supported with respect to the second cylindrical portion 30 so as to be able to move axially but not to rotate relative to the second cylindrical portion 30 by engaging the inner diameter side uneven portion 36 with the outer diameter side uneven portion 31 of the second member 3.

[0075] The frictional engagement portion 4 may include a return spring that elastically biases the first friction plate 32 and the second friction plate 33 in a direction that separates them from each other.

[0076] The cam device 5 includes a drive cam 37, a holder 38, a plurality of rolling elements 39 (three in the illustrated example), and a torsion coil spring 80.

[0077] The drive cam 37 has a cam surface 40, which is a circumferentially uneven surface, on one axial side surface, and a gear portion 41 on a circumferential portion of the outer circumferential surface. In this example, the drive cam 37 has a main body portion 42 formed in a hollow circular shape, and a generally fan-shaped protrusion 43 that protrudes radially outward from one circumferential location of the main body portion 42.

[0078] The cam surface 40 is provided on one axial side surface of the main body portion 42. The cam surface 40 is configured by repeatedly arranging a bottom portion 44, an inclined surface portion 45a, a flat surface portion 46, and an inclined surface portion 45b in this order multiple times (three times in the illustrated example). Of the cam surface 40, the flat surface portion 46 is located furthest on one axial side, and the bottom portion 44 is located furthest on the other axial side. The inclined surface portions 45a and 45b are inclined in opposite directions, and have the same absolute value of the inclination angle with respect to an imaginary plane perpendicular to the central axis of the drive cam 37.

[0079] The gear portion 41 is provided on the radially outer surface of the protrusion 43 .

[0080] The drive cam 37 has a cam-side locking hole 81 that opens at least to the other axial side surface. In this example, the cam-side locking hole 81 is provided so as to open to a circumferentially intermediate portion and a radially intermediate portion of the other axial side surface of the protrusion 43. That is, in this example, the cam-side locking hole 81 is configured as a bottomed hole that opens only to the other axial side surface of the drive cam 37.

[0081] However, when implementing the electric friction clutch device of the present disclosure, the cam-side locking hole may be provided so as to axially penetrate the protrusion, or may be provided in a portion of the drive cam other than the protrusion.

[0082] The drive cam 37 is supported by a radial rolling bearing 47 so as to be rotatable relative to the support member 10 but not to be displaced in the axial direction. The radial rolling bearing 47 is disposed between the inner peripheral surface of the main body 42 and the outer peripheral surface of the other axial end of the fixed cylinder 11.

[0083] The radial rolling bearing 47 includes an inner ring 48, an outer ring 49, and a plurality of rolling elements 50 disposed between the inner ring 48 and the outer ring 49 so as to be freely rollable.

[0084] The inner ring 48 is fitted onto the other axial end of the fixed cylindrical portion 11 , and the other axial side surface thereof abuts against one axial side surface of the flange portion 12 .

[0085] The outer ring 49 is fitted into the main body 42, and one axial side surface thereof abuts against a stepped surface 51 provided on the inner peripheral surface of the main body 42 and facing the other axial side.

[0086] Radial rolling bearing 47 uses balls as rolling elements 50 and is configured as a single-row angular contact ball bearing with a contact angle. However, the radial rolling bearing for supporting the drive cam rotatably relative to the fixed member is not particularly limited as long as it can support radial and thrust loads, and can also be configured as a single-row deep groove ball bearing, tapered roller bearing, etc.

[0087] The holder 38 is supported so as to be unable to rotate relative to the support member 10 but to be movable in the axial direction. For this purpose, the holder 38 has a female spline portion 52 on its inner circumferential surface. The female spline portion 52 of the holder 38 is spline-engaged with the male spline portion 13 of the support member 10 so as to be movable relative to the male spline portion 13 in the axial direction.

[0088] 14 to 17, holder 38 is configured in the shape of a hollow circular plate, and has rectangular holes 53 penetrating in the axial direction at a plurality of locations (three locations in the illustrated example) around a radially middle portion, and has support plate portions 54a and 54b in the shape of approximately semicircular plates that protrude toward the other axial direction from both radially opposite portions of rectangular holes 53. Support plate portions 54a and 54b each have support holes 55a and 55b that are circular holes penetrating in the radial direction.

[0089] Each rolling body 39 has a rolling surface 69 on its outer surface that is in rolling contact with the cam surface 40, and is held in the holder 38 so as to be able to freely rotate (spin) around its own central axis (spinning axis) C, which is arranged in a radial direction around the central axis of the holder 38.

[0090] In this example, each rolling element 39 has a cylindrical shape and is rotatably supported relative to the holder 38 by a columnar support shaft 57 and a plurality of rollers 58. Specifically, the rolling elements 39 are arranged around an axially intermediate portion of the support shaft 57 (a radially intermediate portion of the support shaft 57 centered on the central axis of the holder 38), and each roller 58 is rollably arranged between the outer peripheral surface of the support shaft 57 and the inner peripheral surface of the rolling elements 39. Furthermore, both axial ends of the support shaft 57, i.e., both radially intermediate ends of the support shaft 57 centered on the central axis of the holder 38, are fitted into support holes 55a, 55b of the support plate portions 54a, 54b.

[0091] Furthermore, in this example, the cam device 5 is provided with a retaining member 60 that prevents the support shaft 57 from being displaced in the axial direction of the support shaft 57 (radial direction about the central axis of the holder 38) relative to the holder 38. In this example, the retaining member 60 is configured as a cylindrical pin. The retaining member 60 is press-fitted into a through-hole 59 that penetrates a portion of the support shaft 57 that is radially inward of the holder 38 in the axial direction of the holder 38, and into a locking hole 56 that penetrates a support plate portion 54a on the radially inner side of the holder 38 in the axial direction of the holder 38. This prevents the support shaft 57 from being displaced relative to the holder 38.

[0092] It should be noted that when implementing the present disclosure, the shape of the retaining member, the engagement of the retaining member with the holder and the support shaft, and other aspects are not limited to those of this example and can be determined as desired. For example, as shown in Fig. 22, a locking groove 79 can be formed around the entire circumference of the support shaft 57a on the inner side in the radial direction of the holder 38, and the middle portion of the retaining member 60 press-fitted into the locking hole 56 can be positioned inside the locking groove 79 to prevent displacement of the support shaft 57a with respect to the holder 38. According to the alternative example shown in Fig. 22, when assembling the support shaft 57a to the holder 38, it is not necessary to align the phase of the support shaft 57a in the rotational direction, thereby reducing assembly costs.

[0093] With the rolling elements 39 held in the holder 38 so as to be free to rotate (spin) about the rotation axis C, one axial side portion of the rolling elements 39 is disposed inside the rectangular hole 53. Also, each of the rolling elements 39 has a rolling surface 69 provided on its outer circumferential surface in rolling contact with a cam surface 40 provided on one axial side surface of the drive cam 37.

[0094] The torsion coil spring 80 is stretched between the drive cam 37 and a fixed part that does not rotate during use, and applies elastic force in a direction that rotates the drive cam 37 in a direction that shortens the gap between the drive cam 37 and the holder 38.

[0095] Torsion coil spring 80 is formed by bending an elastic metal wire. In this example, torsion coil spring 80 has a pair of arms 83 a, 83 b and an elastic deformation portion 82 that connects the pair of arms 83 a, 83 b to each other.

[0096] The elastic deformation portion 82 is curved in an arc shape when viewed from the axial direction. In this example, the elastic deformation portion 82 is curved in an approximately 3 / 4 arc shape when viewed from the axial direction in a free state before being assembled between the drive cam 37 and the fixed portion.

[0097] In addition, when implementing the present disclosure, the elastic deformation portion can also be configured in a spiral shape by winding a metal wire multiple times.

[0098] Of the pair of arm portions 83a, 83b, one arm portion 83a is bent and extends from one end of the elastic deformation portion 82 toward one side in the axial direction, and the other arm portion 83b is bent and extends from the other end of the elastic deformation portion 82 toward the other side in the axial direction.

[0099] The torsion coil spring 80 is assembled between the drive cam 37 and the fixed portion in a state in which the elastically deforming portion 82 is disposed on the other axial side of the drive cam 37 and the pair of arm portions 83a, 83b are elastically deformed so as to approach each other in the circumferential direction, as shown by the two-dot chain line in Fig. 18. Specifically, one arm portion 83a is engaged (inserted) into a cam-side engaging hole 81 provided in the drive cam 37 from the other axial side, and the other arm portion 83b is engaged (inserted) into a portion of the fixed portion other than the support member 10, for example, a fixed-side engaging hole provided in the housing. This applies an elastic force to the drive cam 37 in a direction that rotates the drive cam 37 in a direction that reduces the gap between the drive cam 37 and the holder 38.

[0100] The magnitude of the elastic force of the torsion coil spring 80 is appropriately set so that when the electric motor constituting the electric actuator 6 is de-energized, the drive cam 37 can be rotated in a direction that shortens the gap between it and the holder 38, and so that the force required to rotate the drive cam 37 in a direction that lengthens the gap between it and the holder 38 by energizing the electric motor in order to connect the friction engagement portion 4 is not excessively large.

[0101] In the cam device 5, as the drive cam 37 rotates, the amount by which the rolling element 39 rides up from the bottom 44 of the cam surface 40 increases or decreases, thereby displacing the holder 38 in the axial direction.

[0102] There are no particular limitations on the materials that make up the drive cam 37, holder 38, and rolling elements 39, but for example, the drive cam 37 and / or holder 38 can be made as a single unit from sintered metal, which allows drive cams 37 and / or holders 38 with complex shapes to be manufactured at low cost.

[0103] The electric actuator 6 drives and rotates the drive cam 37. In this example, the electric actuator 6 includes an electric motor (not shown) and a reducer 61. The reducer 61 is configured by meshing a worm 62, which is driven and rotated by the electric motor, with a gear portion 41 provided on the outer circumferential surface of the drive cam 37.

[0104] In this example, the reducer 61 does not have a self-locking function.

[0105] The pressing member 7 faces the friction plate that is located furthest from the other axial side among the first friction plate 32 and the second friction plate 33, i.e., the first friction plate 32 that is furthest from the other axial side in this example, and is arranged so as to be able to move toward and away from the first friction plate 32 that is furthest from the other axial side in the axial direction.

[0106] In this example, the pressing member 7 is formed by bending a metal plate having sufficient strength and rigidity, such as a steel plate, into a generally crank-shaped cross section. Specifically, the pressing member 7 has a hollow circular plate-like side plate portion 63, a cylindrical portion 64 bent from the radially outer end of the side plate portion 63 toward the other axial side, and a pressing plate portion 65 bent from the axially outer end of the cylindrical portion 64 toward the radially outer side.

[0107] Side plate portion 63 is fitted onto first member 2 so as to allow relative displacement in the axial direction. Specifically, side plate portion 63 is fitted onto one axial side portion of large-diameter cylindrical portion 19 of shaft body 15 without rattle and so as to allow relative displacement in the axial direction. In this way, pressing member 7 is supported onto first member 2 so as to allow relative displacement in the axial direction.

[0108] The pressing plate portion 65 has a generally S-shaped cross section, and one axial side surface of the radially outer portion faces the other axial side surface of the first friction plate 32 on the other axial side furthest to the other axial side.

[0109] The rolling bearing 8 is disposed between the holder 38 and the pressing member 7 .

[0110] In this example, the rolling bearing 8 is a single-row angular contact ball bearing capable of supporting radial and thrust loads. That is, the rolling bearing 8 includes an outer ring 66, an inner ring 67, and balls 68 arranged to roll freely between the outer ring 66 and the inner ring 67. The rolling bearing 8 is sandwiched between one axial side surface of the holder 38 and the other axial side surface of the side plate 63 of the pressing member 7. In other words, one axial side surface of the outer ring 66 abuts against the other axial side surface of the side plate 63, and the other axial side surface of the inner ring 67 abuts against one axial side surface of the holder 38.

[0111] The elastic member 9 elastically biases the pressing member 7 toward the other axial direction. For this reason, the elastic member 9 is sandwiched in an elastically compressed state between the pressing member 7 and the first member 2. As a result, regardless of the axial dimension of the cam device 5, a preload is applied to the rolling elements 39 of the cam device 5 and the rolling bearings 8, 23, 47, preventing harmful slippage at the rolling contact points.

[0112] It is preferable that the magnitude of the elastic force of elastic member 9 is small, regardless of the axial dimension of cam device 5, as long as it is possible to prevent harmful slippage at the rolling contact portions of cam device 5 and rolling bearings 8, 23, 47. In other words, the magnitude of the elastic force of elastic member 9 is not so large that, when power is cut off to the electric motor that constitutes electric actuator 6, the elastic force of elastic member 9 elastically presses holder 38 toward the other axial side, which is the direction in which the axial distance from drive cam 37 is reduced, thereby reducing the axial dimension of cam device 5.

[0113] In this example, the elastic member 9 is configured by combining two disc springs in series with their smaller diameter ends facing each other. However, the elastic member can also be configured by combining two disc springs in series with their larger diameter ends facing each other. Alternatively, the elastic member can be configured by one or three or more disc springs.

[0114] In the electric friction clutch device 1 of this example, the elastic member 9, a portion of the pressing member 7, and the rolling bearing 8 are arranged radially inside the first cylindrical portion 16 of the first member 2, regardless of the axial dimension of the cam device 5.

[0115] In this example, even when the rolling elements 39 are located at the bottom 44 and the axial dimension of the cam device 5 is at its smallest, the elastic member 9, one axial side portion and side plate portion 63 of the cylindrical portion 64 of the pressing member 7, the rolling bearing 8, and one axial side portion of the holder 38 are located radially inside the first cylindrical portion 16. More specifically, in the electric friction clutch device 1 of this example, the rolling bearing 8 and one axial side portion of the holder 38 are disposed radially inside the cylindrical portion 64 of the pressing member 7, and the first cylindrical portion 16 is disposed around the one axial side portion and side plate portion 63 of the cylindrical portion 64, and the elastic member 9.

[0116] The electric friction clutch device 1 of this example controls the supply of electricity to the electric motor that constitutes the electric actuator 6 and adjusts the rotational phase of the drive cam 37 of the cam device 5, thereby switching between a connection mode in which the first member 2 and the second member 3 rotate together, and a disconnection mode in which the first member 2 and the second member 3 rotate relative to each other.

[0117] To switch the electric friction clutch device 1 to the engagement mode, the electric motor is energized to rotate the drive cam 37 against the elastic force of the torsion coil spring 80, causing the rolling elements 39 to be positioned on the flat surface portion 46 or to increase the amount of movement of the rolling elements 39 onto the inclined surface portion 45a (or 45b). This displaces the holder 38 toward one axial side, which increases the axial distance between the holder 38 and the drive cam 37, and presses the pressing member 7 and the rolling bearing 8 toward one axial side against the elastic force of the elastic member 9. Furthermore, the pressing member 7 presses the first friction plate 32, which is closest to the other axial side, toward one axial side against the elastic forces of the elastic member 9 and the return spring. This presses the first friction plate 32 and the second friction plate 33 against each other, connecting the friction engagement portions 4, causing the first member 2 and the second member 3 to rotate integrally.

[0118] In the electric friction clutch device 1 of this embodiment, when the connected mode is maintained, the electric motor continues to be energized in order to maintain the phase of the drive cam 37 regardless of the elastic force of the torsion coil spring 80.

[0119] In contrast, to switch the electric friction clutch device 1 to the disengagement mode, the drive cam 37 is rotated by energizing the electric motor, or the drive cam 37 is rotated by the elastic force of the torsion coil spring 80 by stopping the energization of the electric motor, thereby positioning the rolling elements 39 at the bottom 44 or reducing the amount of riding up onto the inclined surface 45a (or 45b). This displaces the holder 38 toward the other axial side, which is the direction in which the axial distance from the drive cam 37 decreases, thereby reducing the force pressing the pressing member 7 toward one axial side. When the force pressing the pressing member 7 toward one axial side decreases, the pressing member 7 and the rolling bearing 8 are pressed toward the other axial side, mainly due to the elastic restoring force of the elastic member 9. As a result, the force pressing the first friction plate 32 and the second friction plate 33 against each other decreases due to the action of the return spring, and eventually a gap is formed between the first friction plate 32 and the second friction plate 33, and the force pressing the first friction plate 32 and the second friction plate 33 against each other is lost, i.e., released. This cuts the friction engagement portion 4, and allows the first member 2 and the second member 3 to rotate relative to each other.

[0120] In the electric friction clutch device 1 of this example, the torsion coil spring 80 applies elastic force to the drive cam 37 in a direction that rotates the drive cam 37 in a direction that reduces the gap between the drive cam 37 and the holder 38. Therefore, even if the power supply to the electric motor is stopped, the electric friction clutch device 1 can be maintained in the disengagement mode.

[0121] In the electric friction clutch device 1 of this example, the plurality of rolling elements 39 that make up the cam device 5 are rotatably held in the holder 38. Therefore, even if slippage occurs between the cam surface 40 of the drive cam 37 and the rolling surface 69 of the rolling element 39, there is no variation in the amount of lift from the bottom 44 of the cam surface 40 among the plurality of rolling elements 39. Therefore, the amount of axial displacement of the holder 38 can be sufficiently and reliably ensured, and the amount of expansion / contraction in the axial dimension of the cam device 5 can be sufficiently and reliably ensured.

[0122] Therefore, when the electric friction clutch device 1 is switched to the connection mode, a sufficient pressing force between the first friction plates 32 and the second friction plates 33 can be ensured, and a sufficient fastening force can be ensured for the friction engagement portion 4. Furthermore, when the electric friction clutch device 1 is switched to the disconnection mode, the first friction plates 32 and the second friction plates 33 can be sufficiently separated from each other, that is, a gap can be reliably formed between the first friction plates 32 and the second friction plates 33, thereby preventing the occurrence of drag.

[0123] In this example, cylindrical rollers are used as the rolling elements 39. Therefore, compared to the conventional structure shown in Fig. 35, in which balls 106c are used as the rolling elements of the cam device 106, the occurrence of slippage can be suppressed.

[0124] Furthermore, in the electric friction clutch device 1 of this example, a retaining member 60 is press-fitted into a through-hole 59 that penetrates one axial side portion of the support shaft 57 and into a locking hole 56 that penetrates the axial direction of the support plate portion 54b on the radially inner side of the holder 38. This makes it possible to prevent the support shaft 57 from being accidentally displaced relative to the holder 38 in its own axial direction (radial direction centered on the central axis of the holder 38).

[0125] In this example, the cam device 5 includes a torsion coil spring 80 that applies elastic force to the drive cam 37 in a direction that rotates the drive cam 37 in a direction that shortens the gap between the drive cam 37 and the holder 38 .

[0126] For this reason, in the electric friction clutch device 1 of this example, if a malfunction or the like occurs and power supply to the electric motor constituting the electric actuator 6 is stopped, the elastic force of the torsion coil spring 80 causes the drive cam 37 to rotate in a direction that reduces the gap between it and the holder 38. As a result, when the holder 38 is displaced toward the other axial side, the force pressing the pressing member 7 toward one axial side decreases, and the pressing member 7 and the rolling bearing 8 are pressed toward the other axial side mainly by the elastic restoring force of the elastic member 9. Then, based on the action of the return spring, the force pressing the first friction plate 32 and the second friction plate 33 against each other is lost, and the friction engagement portion 4 is cut off.

[0127] As described above, in the electric friction clutch device 1 of this embodiment, if the electric actuator 6 breaks down or the like, the device can be quickly switched to the disengagement mode, making it easy to ensure safety.

[0128] In order to quickly switch the electric friction clutch device 1 to the disengagement mode in the event of a malfunction of the electric actuator 6, it is also possible to adopt a structure in which the elastic force of the elastic member 9 that elastically urges the pressing member 7 toward the other axial direction is increased. However, in this case, a large axial load will always be applied to the rolling contact portions of the cam device 5 and the rolling bearings 8, 23, 47, which may shorten the life of the cam device 5 and / or the rolling bearings 8, 23, 47.

[0129] In contrast, in this example, the function of quickly switching the electric friction clutch device 1 to the disengagement mode in the event of a failure of the electric actuator 6, etc., is achieved by using the torsion coil spring 80 to apply an elastic force to the drive cam 37 in a direction that rotates the drive cam 37 in a direction that reduces the gap between the drive cam 37 and the holder 38. As a result, the magnitude of the elastic force of the elastic member 9 can be kept to a level that prevents harmful slippage from occurring at the rolling contact portions of the cam device 5 and the rolling bearings 8, 23, 47, regardless of the axial dimension of the cam device 5. In other words, it is possible to prevent excessive axial loads from being constantly applied to the rolling contact portions of the cam device 5 and the rolling bearings 8, 23, 47, making it easier to ensure the life of the cam device 5 and / or the rolling bearings 8, 23, 47.

[0130] According to the electric friction clutch device 1 of this embodiment, the manufacturing cost of the first member 2 that supports the first friction plate 32 and is connected to the first rotating member 72 can be reduced.

[0131] 35, a first member 103 having a small diameter cylindrical portion 103a fitted and fixed to the outside of an input member 101 and a large diameter cylindrical portion 103c onto which a first friction plate 105a is fitted so as to be movable in the axial direction is integrally formed as a whole. If a first member 103 having such a substantially F-shaped cross section is to be produced by forging, the processing load will be large, which may increase manufacturing costs.

[0132] In contrast, in this example, the first member 2, which has the first cylindrical portion 16 that supports the first friction plate 32 and is connected to the first rotating member 72, is configured by joining and fixing the flange member 14, which is a pressed product, and the shaft body 15, which is a forged product. This makes it possible to reduce the manufacturing cost of the first member 2.

[0133] 35, the pressing member 108, the rolling bearing 109, and the drive cam 106a are arranged side by side between the first member 103 and the cam plate 106b in the axial direction. This makes the axial dimension of the clutch device 100 of the conventional structure bulky.

[0134] In contrast to this, in this example, the elastic member 9, a portion of the pressing member 7, and the rolling bearing 8 are arranged radially inside the first cylindrical portion 16 of the first member 2, regardless of the axial dimension of the cam device 5. Therefore, according to the electric friction clutch device 1 of this example, the axial dimension can be reduced compared to the clutch device 100 of the conventional structure.

[0135] In this example, the pressing plate portion 65 of the pressing member 7 has a substantially S-shaped cross section. That is, the portion of the pressing member 7 that presses the other axial side surface of the first friction plate 32 that is closest to the other axial side is configured with a convex curved surface. This prevents excessive sensitivity to changes in the pressing force of the pressing member 7 that change in accordance with the axial displacement of the holder 38, thereby improving the controllability of the electric friction clutch device 1.

[0136] In addition, in this example, the elastic member 9 is configured as a disc spring, which makes it easier to reduce the axial dimension compared to when a compression coil spring is used as the elastic member that elastically presses the pressing member toward the other axial direction. Furthermore, because disc springs have nonlinear spring characteristics, they can prevent excessive loads from being applied to the rolling bearings 8, 23, 47 and the meshing portion between the gear portion 41 and the worm 62, thereby improving durability. However, when implementing the present disclosure, a compression coil spring can also be used as the elastic member.

[0137] In this example, the inclined surface portions 45a, 45b of the cam surface 40 of the drive cam 37 are configured as flat surfaces with a constant inclination angle relative to an imaginary plane perpendicular to the central axis of the drive cam 37. However, when implementing the present disclosure, as shown in FIG. 23 , the inclined surface portion of the cam surface connecting the bottom portion and the flat surface portion can also be configured from a plurality of flat and / or curved surfaces. Specifically, in an initial state before the first and second friction plates are worn, the rolling elements climb up the inclined surface portions from the bottom portions, and as the holder moves toward one axial side, the pressing member moves toward one axial side. Until the pressing member contacts the other axial side surface of the friction plate closest to the other axial side of the first or second friction plate (initial piston touch point), the inclination angle of the inclined surface portions can be made relatively large so that the amount of axial displacement of the holder relative to the rotation angle of the drive cam is large, i.e., so that the time until the initial piston touch point can be shortened. In contrast, after the initial piston touch point is exceeded, the inclination angle of the inclined surface portion can be made relatively small to ensure good control of the fastening force of the frictional engagement portion by the pressing member. Also, the area where the gear portion provided on the outer peripheral surface of the drive cam is formed can be made small, thereby reducing manufacturing costs.

[0138] [Example 2] 24 shows a second example of an embodiment of the present disclosure. In this example, a torsion coil spring 80a is stretched between the drive cam 37 and the support member 10a.

[0139] For this reason, the support member 10a has a slit 84 at one location in the circumferential direction of the flange portion 12a, which opens to the outer circumferential surface of the flange portion 12a and to both side surfaces in the axial direction.

[0140] Of the pair of arms 83a, 83b1 of torsion coil spring 80a, the other arm 83b1, which is engaged with support member 10a, is bent and extends radially inward from the other end of elastic deformation portion 82. The other arm 83b1 is disposed (engaged) inside slit 84 of support member 10a.

[0141] The structure for engaging (supporting) the other arm portion of the torsion coil spring with the support member is not limited to the structure, and for example, the arm portion that is bent and extended in the axial direction can be engaged (inserted) into an engaging hole that passes axially through the flange portion of the support member.

[0142] According to this example, the torsion coil spring 80a can be stretched between the drive cam 37 and the support member 10a before the electric friction clutch device 1 (see FIG. 3, etc.) is assembled into a housing or the like. In other words, the electric friction clutch device 1 including the torsion coil spring 80a can be made into a unit, which improves the ease of handling of the electric friction clutch device 1.

[0143] The configuration and effects of other parts of the second example are the same as those of the first example.

[0144] [Example 3] 25 shows a third example of the embodiment of the present disclosure. In this example, the manner in which one arm portion 83a1 of a pair of arms 83a1, 83b1 of torsion coil spring 80b is engaged with drive cam 37a is different from the structure of the second example.

[0145] In this example, the drive cam 37a does not have a cam-side locking hole 81 that opens to the circumferentially intermediate and radially intermediate portion of the other axial side surface of the protruding portion 43a.

[0146] One arm portion 83a1 is curved in a substantially L-shape when viewed from the radial direction. That is, one arm portion 83a1 has a base half portion 85 that bends and extends from one end of the elastically deforming portion 82 to one side in the axial direction, and a tip half portion 86 that bends from the tip end of the base half portion 85 in the circumferential direction.

[0147] One arm 83a1 is hooked onto an end of one circumferential side of the protruding portion 43a and locked in place. Specifically, the base half 85 is elastically pressed against the end face of one circumferential side of the protruding portion 43a, and the tip half 86 is disposed on one axial side of the protruding portion 43a.

[0148] In this example, there is no need to provide the drive cam 37a with a cam-side locking hole for locking the one arm portion 83a1 of the torsion coil spring 80b, so that the processing cost of the drive cam 37a can be reduced.

[0149] The configuration and effects of other parts of the third example are similar to those of the first and second examples.

[0150] [Example 4] 26 shows a fourth embodiment of the present invention. In this embodiment, the shape of one arm 83a2 of a pair of arms 83a2, 83b1 of torsion coil spring 80c is different from that of the third embodiment.

[0151] Specifically, one arm portion 83a2 is composed of only a base half portion 85 that bends and extends axially to one side from one end of the elastically deforming portion 82. In other words, one arm portion 83a2 has a shape similar to one arm portion 83a1 of the third example without the tip half portion 86.

[0152] One arm portion 83a2 is locked to the drive cam 37a simply by elastically pressing the base half portion 85 against one end face of the protruding portion 43a in the circumferential direction.

[0153] According to this example, the shape of the torsion coil spring 80c can be simplified compared to the structure of the torsion coil spring 80b of the third example, which makes it easier to bend and reduces the manufacturing cost of the torsion coil spring 80c.

[0154] The configuration and effects of other parts of the fourth example are the same as those of the first to third examples.

[0155] [Example 5] 27 and 28 show a fifth example of the embodiment of the present invention. In this example, the manner in which the other arm portion 83b2 of the pair of arm portions 83a2, 83b2 of torsion coil spring 80d is engaged with support member 10 is different from that in the fourth example.

[0156] In this example, the other arm portion 83b2 is locked to a positioning pin 87 that is press-fitted and fixed into a fixed side locking hole 70 (see FIGS. 2, 6, and 9, etc.) provided in the flange portion 12 of the support member 10.

[0157] The other arm portion 83b2 is formed by bending the end of a metal wire that forms the torsion coil spring 80d into a substantially loop shape, as shown in FIG.

[0158] The positioning pin 87 is cylindrical, and its axial middle portion is press-fitted into the fixed-side locking hole 70, thereby supporting and fixing it to the support member 10. One axial end of the positioning pin 87 protrudes to one axial side from one axial side surface of the flange portion 12, and the other axial end of the positioning pin 87 protrudes to the other axial side from the other axial side surface of the flange portion 12.

[0159] The support member 10 is supported and fixed to a part that does not rotate even when in use, such as a housing, by the other axial end of the positioning pin 87 that protrudes to the other axial side from the other axial side of the flange portion 12, and does not rotate or displace even when in use.

[0160] In this example, the other arm portion 83b2 is engaged (fitted) with one axial end of the positioning pin 87 that protrudes from one axial side surface of the flange portion 12 to one axial side.

[0161] According to this example, a structure can be realized in which the torsion coil spring 80d can be stretched between the drive cam 37 and the support member 10 before the electric friction clutch device 1 (see Figure 3, etc.) is assembled to a housing or the like, while reducing the processing costs of the support member 10 compared to the structure of the second example.

[0162] The configuration and effects of other parts of the fifth example are the same as those of the first to fourth examples.

[0163] [Example 6] 29 and 30 show a sixth embodiment of the present invention. In this embodiment, the other arm portion 83b3 of a pair of arms 83a2, 83b3 of torsion coil spring 80e has a base half portion 88 bent radially inward, and a tip half portion 89 bent from the tip of base half portion 88 toward the other axial side.

[0164] The tip half portion 89 is inserted from one axial side through the fixed-side locking hole 70 and the cylindrical member 90 in that order. Specifically, one axial side portion of the tip half portion 89 is loosely fitted into the fixed-side locking hole 70, and the other axial side portion of the tip half portion 89 is press-fit into the cylindrical member 90. This causes the other arm portion 83b3 to be locked to the support member 10.

[0165] The support member 10 is supported and fixed to a part such as a housing that does not rotate even when in use by the cylindrical member 90 in a state where the support member 10 is positioned relative to the part, and does not rotate or displace even when in use.

[0166] According to this example, the shape of the torsion coil spring 80e can be simplified compared to the structure of the torsion coil spring 80d of the fifth example, which makes it possible to facilitate bending and reduce the manufacturing cost of the torsion coil spring 80e.

[0167] The configuration and effects of other parts of the sixth example are the same as those of the first to fifth examples.

[0168] [Example 7] 31 and 32 show a seventh embodiment of the present invention. In this embodiment, the friction engagement portion 4a is formed by alternately stacking five first friction plates 32a and five second friction plates 33.

[0169] The electric friction clutch device of this example includes an end plate 74 having a substantially L-shaped cross section.

[0170] The end plate 74 has a hollow circular plate portion 75 and a protrusion 76 that protrudes from the radially outer portion of one axial side surface of the plate portion 75 toward the one axial side along the entire circumference. The plate portion 75 has an outer diameter side uneven portion 77 on its inner peripheral surface, where recesses and protrusions are arranged alternately in the circumferential direction.

[0171] The end plate 74 is fitted onto the first cylindrical portion 16 so as to prevent relative rotation by engaging the outer diameter side uneven portion 77 with the inner diameter side uneven portion 18 provided on the outer peripheral surface of the first cylindrical portion 16 of the first member 2. The inner peripheral surface of the convex portion 76 of the end plate 74 abuts or closely faces the outer peripheral surface of the retaining ring 35, and one axial side surface of the radially inner surface of the plate portion 75 abuts against the other axial side surface of the retaining ring 35.

[0172] In this example, of the first friction plate 32 and the second friction plate 33, the first friction plate 32a located furthest to one side in the axial direction is opposed to a retaining ring 35 engaged with the first cylindrical portion 16 via an end plate 74, thereby preventing the first friction plate 32a located furthest to one side in the axial direction from being displaced to one side in the axial direction.

[0173] In this example, the inner peripheral surface of the protrusion 76 of the end plate 74 fitted onto the first cylindrical portion 16 is in contact with or closely faces the outer peripheral surface of the retaining ring 35. Therefore, even if centrifugal force is applied to the retaining ring 35 as the first member 2 rotates and the retaining ring 35 tries to lift up, the retaining ring 35 can be prevented from accidentally falling off the first cylindrical portion 16.

[0174] The configuration and effects of other parts of the seventh example are the same as those of the first example.

[0175] [Example 8] 33 to 34(B) show a third embodiment of the present invention. In this embodiment, the inner ring 24 of the radial rolling bearing 23 for rotatably supporting the first member 2a relative to the support member 10 is sandwiched in the axial direction between the other axial surface of the side plate portion 21 of the first member 2a and a nut 78 that is threaded onto the other axial end of the small-diameter cylindrical portion 20a.

[0176] According to this example, even when the rotation speed of the first member 2a is high, the inner ring 24 of the radial rolling bearing 23 can be reliably prevented from shifting in the axial direction relative to the small diameter cylindrical portion 20a.

[0177] The other configurations and effects of the eighth example are the same as those of the first example. [Explanation of symbols]

[0178] 1. Electric friction clutch device 2, 2a First member 3 Second member 4, 4a Friction engagement portion 5 Cam device 6 Electric Actuators 7 Pressing member 8. Rolling bearings 9 Elastic member 10, 10a Support member 11 Fixed cylinder part 12, 12a flange 13 Male spline part 14 Flange member 15 Axis body 16 First cylinder part 17 Circular part 18 Inner diameter uneven part 19 Large diameter cylinder 20, 20a Small diameter cylindrical part 21 Side plate part 22 Locking groove 23 Radial rolling bearings 24 Inner Circle 25 outer ring 26 rolling elements 27 Retaining ring 28 Step surface 29 Retaining ring 30 Second cylinder part 31 Outer diameter side uneven part 32 1st friction plate 33 Second friction plate 34 Outer diameter side unevenness 35 retaining ring 36 Inner diameter uneven part 37, 37a Drive cam 38 Holder 39 Rolling elements 40 Cam surface 41 Gear section 42 Main body 43, 43a protrusion 44 Bottom 45a, 45b Slope section 46 Flat surface section 47 Radial Rolling Bearing 48 Inner Circle 49 Outer Ring 50 rolling elements 51 Step surface 52 Female spline part 53 Rectangular hole 54a, 54b Support plate part 55a, 55b support hole 56 Locking hole 57, 57a Support shaft Around 58 59 Through hole 60 Stopper member 61 Reducer 62 Warm 63 Side plate part 64 Cylindrical part 65 Pressure plate 66 Outer ring 67 Inner Circle 68 balls 69 Rolling surface 70 Fixed side locking hole 71 Female spline part 72 First rotating member 73 Male spline part 74 End Plate 75 Plate section 76 Convex part 77 Outer diameter side unevenness 78 Nut 79 Locking groove 80, 80a, 80b, 80c, 80d, 80e Torsion coil springs 81 Cam side locking hole 82 Elastic deformation part 83a, 83a1, 83a2, 83b, 83b1, 83b2, 83b3 Arm section 84 Slit 85 Base half 86 First half 87 Locating pin 88 Base half 89 First half 90 Cylindrical member 100 Clutch device 101 Input member 102 Output member 103 First member 103a Small diameter cylinder part 103b Side plate part 103c Large diameter cylinder 104 Second member 104a Circular part 104b Cylindrical part 105 Friction engagement part 105a 1st friction plate 105b 2nd friction plate 106 Cam device 106a Drive cam 106a1 Drive side cam surface 106a2 Gear section 106b Cam plate 106b1 Fixed side cam surface 106c ball 107 Electric Actuator 107a Electric motor 107b Reducer 107b1 Output gear 108 Pressing member 109 Rolling bearings 110 Elastic member

Claims

1. A first member; a second member supported coaxially with the first member and capable of relative rotation with respect to the first member; a friction engagement portion having at least one first friction plate and one second friction plate supported so as to be capable of relative displacement in the axial direction; a drive cam having a cam surface on one axial side surface, and supported rotatably but not axially displaceable relative to a fixed portion that does not rotate even when in use; a holder supported axially displaceable but not rotatable relative to the fixed portion; a plurality of rolling elements held by the holder, each having a rolling surface that comes into rolling contact with the cam surface; and a torsion coil spring stretched between the drive cam and the fixed portion, and applying to the drive cam an elastic force that rotates the drive cam in a direction that reduces the gap between the drive cam and the holder; an electric actuator that rotates the drive cam; a pressing member that faces the other axial side surface of the friction plate that is located furthest on the other axial side among the first friction plate and the second friction plate, and is supported so as to be movable toward and away from the friction plate located furthest on the other axial side in the axial direction; a rolling bearing disposed between the holder and the pressing member; an elastic member that elastically biases the pressing member toward the other axial direction; Equipped with By driving the drive cam to rotate with the electric actuator, the holder is displaced in a direction that widens the gap between the holder and the drive cam, and the first friction plate and the second friction plate are pressed against each other, thereby switching to a connection mode in which the first member and the second member rotate together; and by displacing the holder in a direction that narrows the gap between the holder and the drive cam, the force pressing the first friction plate and the second friction plate against each other is released, thereby switching to a disconnection mode in which the first member and the second member rotate relative to each other. Electric friction clutch device.

2. the torsion coil spring has a pair of arm portions and an elastic deformation portion connecting the pair of arm portions, one arm portion of the pair of arm portions is locked to the drive cam, and the other arm portion is locked to the fixed portion; 2. The electric friction clutch device according to claim 1.

3. The drive cam has a cam-side locking hole that opens to at least the other side surface in the axial direction, The tip end of the arm portion is engaged with the cam side engaging hole.

3. The electric friction clutch device according to claim 2.

4. the electric actuator has an electric motor and a drive gear that is rotationally driven by the electric motor directly or via a reducer, the drive cam includes a main body portion having the cam surface on one axial side surface, and a protrusion portion having a gear portion on a radially outer surface thereof that meshes with the drive gear, the protrusion portion protruding radially outward from one circumferential position of the main body portion, The one arm portion is elastically pressed against an end surface on one circumferential side of the protrusion.

3. The electric friction clutch device according to claim 2.

5. the fixed portion includes a support member having a fixed-side locking hole passing through in the axial direction, the support member is positioned relative to a portion of the fixed portion other than the support member by a positioning pin inserted into the fixed-side locking hole, The tip end of the other arm portion is engaged with the positioning pin.

3. The electric friction clutch device according to claim 2.

6. the fixed portion includes a support member having a fixed-side locking hole passing through in the axial direction, a tip end of the other arm portion is inserted through the fixed side locking hole and the tubular member, The support member is positioned relative to a portion of the fixed portion other than the support member by the cylindrical member.

3. The electric friction clutch device according to claim 2.

7. The rolling element has a cylindrical shape, The cam device includes a plurality of support shafts, each of which has both axial end portions supported by the holder, and a plurality of rollers, each of which is rollably disposed between the inner peripheral surface of the rolling element and the outer peripheral surface of the support shaft. The electric friction clutch device according to any one of claims 1 to 6.

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