Friction clutch and method for assembling same

Abstract

A friction clutch device 7 comprises: a retaining ring 32 externally fitted to a second member 102; a pressing plate 36 that faces a lateral surface on one axial side of a friction plate which is either a first friction plate 45 or a second friction plate 46 located furthest on said one axial side, and is externally fitted to the second member 102 in a manner capable of moving axially toward or away from the friction plate located furthest on said one axial side; an elastic member 37 that is sandwiched between the retaining ring 32 and the pressing plate 36 and that elastically biases the pressing plate 36 toward the other axial side; and a spacer 33 and a fastening ring 34 that are locked to a locking groove 15 of the second member 102 and that prevent the retaining ring 32 from being displaced toward said one axial side.

Description

Friction clutch and method of assembling same

[0001] The present disclosure relates to a 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, and a method for assembling the same.

[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] WO 2022 / 074958 describes a normally closed type friction clutch device. The conventional friction clutch device described in WO 2022 / 074958 includes a friction engagement portion having at least one first friction plate and one second friction plate supported to allow relative axial displacement, a pressure plate supported to allow axial movement toward or away from the first friction plate or the second friction plate, a disc spring that elastically presses the first friction plate and the second friction plate in a direction pressing them against each other via the pressure plate, and a pressing device that presses the pressure plate in a direction to release the force pressing the first friction plate and the second friction plate against each other.

[0005] In a conventional friction clutch device, the first friction plate and the second friction plate are connected by the disc spring pressing the first friction plate and the second friction plate together via the pressure plate when the pressure device is not exerting a pressing force. In contrast, the friction clutch device is disconnected by pressing the pressure plate against the elastic force of the disc spring in a direction that releases the force pressing the first friction plate and the second friction plate together.

[0006] International Publication No. 2022 / 074958

[0007] In order to ensure an appropriate torque capacity in a friction clutch device, it is necessary to ensure an appropriate pressing force between the first friction plate and the second friction plate.

[0008] In the conventional friction clutch device described in WO 2022 / 074958, the disc spring that presses the first friction plate and the second friction plate toward each other is elastically sandwiched between a small-diameter flange portion provided on the rotating member and a pressure plate that is supported so as to be able to move axially relative to the small-diameter flange portion. The axial distance between the small-diameter flange portion and the pressure plate varies due to manufacturing errors and assembly errors of the components that make up the friction clutch device.

[0009] Therefore, in order to adjust the pressing force of the disc spring to an appropriate level, a disc spring having an appropriate free height is selected from multiple types of disc springs with different free heights depending on the axial distance between the small diameter flange portion and the pressing plate, and the disc spring is elastically sandwiched between the small diameter flange portion and the pressing plate. In other words, it is necessary to prepare multiple types of disc springs with different free heights, which may increase manufacturing costs.

[0010] 10(d), a structure may be considered in which the disc spring 200 is elastically sandwiched between a retaining ring 202 fitted onto the shaft member 201 and a pressure plate 203. The retaining ring 202 is prevented from being displaced to one axial side (upper side in FIG. 10(d)), that is, away from the pressure plate 203, by a retaining ring 205 engaged with a locking groove 204 provided on the outer circumferential surface of the shaft member 201.

[0011] 10(d), the pressing force of the disc spring 200 can be adjusted by adjusting the axial thickness of the retaining ring 202. This adjustment can be performed, for example, as follows.

[0012] First, as shown in Figure 10 (a), a first distance L1, which is the axial distance between the inner surface of the engagement groove 204 facing the other axial side and the end face on one axial side of the shaft member 201, is measured.

[0013] 10(b), the pressing plate 203 and the disc spring 200 are fitted onto the shaft member 201, and then the disc spring 200 is pressed from one axial side with a predetermined load using a pressing jig 206. In this state, a second distance L2, which is the axial distance between the end face on one axial side of the shaft member 201 and the end portion on one axial side of the disc spring 200, is determined. Then, ΔL (= L2 - L1), which is the difference between the second distance L2 and the first distance L1, is determined.

[0014] 10(c), the axial thickness t of the retaining ring 205 is measured. Then, the retaining ring 202 is selected such that the thickness T of the portion of the retaining ring 202 that is disposed adjacent to the other axial side of the retaining ring 205 has a size (=ΔL−t) obtained by subtracting the axial thickness T of the retaining ring 205 from the difference ΔL between the second distance L2 and the first distance L1.

[0015] As shown in Figures 10(c) and 10(d) in that order, the retaining ring 202 is fitted onto the shaft member 201, and a retaining ring 205 is further engaged with the engaging groove 204, thereby preventing the retaining ring 202 from displacing to one side in the axial direction.

[0016] The cost of preparing a plurality of types of retainer rings 202 with different axial thicknesses can be kept lower than the cost of preparing a plurality of types of disc springs with different free heights.

[0017] 10(a) to 10(d), however, there is a problem in that it is difficult to measure the first distance L1, which is the axial distance between the inner surface of the locking groove 204, which has a small axial width and faces the other axial side, and the end face on one axial side of the shaft member 201. In addition, it is necessary to measure the dimensions of three locations for each device: the first distance L1, the second distance L2, and the axial thickness t of the retaining ring 205. This may increase the number of work steps and the manufacturing cost.

[0018] An object of the present disclosure is to provide a friction clutch device and an assembly method thereof that can appropriately adjust the pressing force of an elastic member while reducing manufacturing costs.

[0019] A friction clutch device according to one aspect of the present disclosure includes a first member, a second member, a retaining ring, a spacer, a retaining ring, a friction engagement portion, a pressure plate, an elastic member, and a pressure device.

[0020] The second member has a locking groove on its outer circumferential surface, and is supported coaxially with the first member so as to be rotatable relative to the first member.

[0021] The retaining ring is fitted onto the second member.

[0022] The spacer and the retaining ring are engaged with the engaging groove in order from one axial side, thereby preventing the retaining ring from being displaced to one axial side.

[0023] The friction engagement portion has at least one first friction plate supported on the inner peripheral surface of the first member, and at least one second friction plate supported on the outer peripheral surface of the second member so as to allow relative axial displacement with respect to the at least one first friction plate.

[0024] The pressure plate faces the side surface on one axial side of the friction plate that is located furthest axially from the first friction plate and the second friction plate, and is externally fitted onto the second member to enable movement toward and away from the friction plate located furthest axially from the friction plate that is located furthest axially from the second friction plate.

[0025] The elastic member is sandwiched between the retaining ring and the pressure plate, and elastically biases the pressure plate toward the other axial side.

[0026] The pressing device presses the pressing plate toward one axial side.

[0027] In one aspect of the friction clutch device of the present disclosure, by releasing the force pressing the pressure plate toward one axial side by the pressing device, the first friction plate and the second friction plate are pressed against each other based on the elastic force of the elastic member, thereby switching to a connection mode in which the first member and the second member rotate as a unit; and by pressing the pressure plate toward one axial side by the pressing device, the force pressing the first friction plate and the second friction plate against each other based on the elastic force of the elastic member is released, thereby switching to a disconnection mode in which the first member and the second member rotate relative to each other.

[0028] In one embodiment of the friction clutch device of the present disclosure, the retaining ring has a base portion that is fitted onto the second member, and a visor portion that protrudes from the radially outer portion of the base toward one axial side and covers the spacer and the retaining ring.

[0029] In a friction clutch device according to one aspect of the present disclosure, the elastic member includes a disc spring.

[0030] A method for assembling a friction clutch device according to one aspect of the present disclosure includes a temporary assembly step, a measurement step, and a spacer assembly step.

[0031] In the temporary assembly step, the pressing plate, the elastic member, and the retaining ring are fitted onto the second member in this order from the other axial side, and the retaining ring is engaged with the engaging groove.

[0032] In the measurement process, after the preliminary assembly process, a load of a predetermined magnitude is applied to the end face on one axial side of the retaining ring, facing the other axial side, thereby displacing the retaining ring to the other axial side, and the amount of displacement of the retaining ring to the other axial side is measured.

[0033] In the spacer assembling step, the spacer having the same thickness as the displacement amount is locked in the locking groove from one axial side.

[0034] According to the friction clutch device and the assembly method thereof of the present disclosure, it is possible to appropriately adjust the pressing force of the elastic member while suppressing manufacturing costs.

[0035] FIG. 1 is a schematic cross-sectional view of a drive system incorporating a two-speed transmission equipped with a friction clutch device according to an embodiment of the present disclosure. FIG. 2(a) is a schematic cross-sectional view showing a torque transmission path in a low reduction ratio mode of the two-speed transmission, and FIG. 2(b) is a schematic cross-sectional view showing a torque transmission path in a high reduction ratio mode of the two-speed transmission. FIG. 3 is a cross-sectional view of the two-speed transmission. FIG. 4 is a cross-sectional view of the friction clutch device. FIG. 5 is an exploded perspective view showing first and second friction plates constituting the friction clutch device. FIG. 6 is an enlarged view of a portion X in FIG. 4. FIG. 7 is a perspective view showing a drive cam removed from a pressing device constituting the friction clutch device. FIG. 8 is an exploded perspective view showing a driven cam and rolling elements removed from a pressing device constituting the friction clutch device. FIGS. 9(a) to 9(d) are partially enlarged cross-sectional views illustrating a method of assembling the friction clutch device in sequence. 10(a) to 10(d) are partially enlarged cross-sectional views illustrating the assembly method of the friction clutch device of the prior invention in the order of steps.

[0036] An example of an embodiment of the present disclosure will be described with reference to FIGS. 1 to 9(d).

[0037] Hereinafter, a friction clutch device according to one embodiment of the present disclosure will be described based on an example in which the friction clutch device is incorporated into an automotive two-speed transmission 1. The two-speed transmission 1 is disposed between a drive source 2 such as an electric motor or an engine and a differential device 3, and transmits the output torque of the drive source 2 to the differential device 3 while increasing (decelerating) or without increasing it.

[0038] However, the friction clutch device of one embodiment of the present disclosure can be incorporated and used in the portion between a pair of rotating members or between a rotating member and a fixed member that constitutes various mechanical devices, not limited to two-speed transmissions for automobiles.

[0039] The two-speed transmission 1 includes an input member 4 , an output member 5 , a rotating member 6 , a friction clutch device 7 , an engagement device 8 , and a planetary reduction mechanism 9 .

[0040] 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 input member 4. The axial direction, radial direction, and circumferential direction of the input member 4 coincide with the axial direction, radial direction, and circumferential direction of the output member 5 and also coincide with the axial direction, radial direction, and circumferential direction of the rotating member 6. Furthermore, one axial side refers to the right side in Figures 1 to 4 and the upper side in Figures 9(a) to 9(d), and the other axial side refers to the left side in Figures 1 to 4 and the lower side in Figures 9(a) to 9(d).

[0041] The input member 4 is formed of a housing that accommodates the two-speed transmission 1, and is rotatably supported by a fixed portion 70 that does not rotate even during use, by a rolling bearing (not shown). In this example, the input member 4 is cylindrical (hollow). The input member 4 also has an input gear 12 at one axial end that meshes with a drive gear 11 provided on an output shaft 10 of the drive source 2. In other words, the input member 4 can be rotationally driven by the drive source 2.

[0042] The output member 5 is supported coaxially with the input member 4 and rotatably relative to the input member 4. In this example, the output member 5 is supported radially inside the cylindrical input member 4 via a ring gear 95, a planetary gear 97, and a carrier 96 that constitute the planetary reduction mechanism 9 so as to be rotatable relative to the input member 4. The output member 5 also has an output gear 13 at one axial end. The output gear 13 meshes with a gear provided at the input portion of the differential device 3. In other words, the output member 5 is connected to the input portion of the differential device 3 so as to be able to transmit torque.

[0043] The rotating member 6 is supported coaxially with the input member 4 and the output member 5 and is capable of relative rotation with respect to the input member 4 and the output member 5. In this example, the rotating member 6 is rotatably supported with respect to the fixed part 70 via the ring gear, planetary gears, and sun gear that constitute the planetary reduction mechanism 9, the pressing device 38 that constitutes the friction clutch device 7, the bearing device 14, etc.

[0044] The rotary member 6 has an engaging groove 15 formed on the outer peripheral surface of the axially intermediate portion thereof over the entire circumference.

[0045] In this example, the rotating member 6 has a flange portion 16 that protrudes radially outward at a portion located on the other axial side of the locking groove 15 .

[0046] The flange portion 16 has an inner diameter side circular ring portion 17 in the form of a hollow circular plate, a cylindrical portion 18 bent from the radially outer end of the inner diameter side circular ring portion 17 toward the other axial side, and an outer diameter side circular ring portion 19 in the form of a hollow circular plate bent from the axially outer end of the cylindrical portion 18 toward the radially outer side.

[0047] The inner diameter side circular ring portion 17 has through holes 20 penetrating in the axial direction at a plurality of circumferential positions in a radially intermediate portion.

[0048] In this example, the rotary member 6 is configured by connecting and fixing a shaft member 21 and a flange element 22 .

[0049] The shaft member 21 has a stepped cylindrical shape. Specifically, the shaft member 21 has, in order from one axial end, a first small-diameter cylindrical portion 23, a large-diameter cylindrical portion 24, a medium-diameter cylindrical portion 25, and a second small-diameter cylindrical portion 26. The shaft member 21 also has a through-hole 27 that passes through the center of the shaft member 21 in the axial direction and allows lubricating oil to flow through.

[0050] The locking groove 15 is formed around the entire outer circumferential surface of one axial side portion of the large-diameter cylindrical portion 24 .

[0051] In this example, the large-diameter cylindrical portion 24 has a protruding portion 28 at its end on the other axial side, which protrudes radially outward beyond the portion adjacent to the one axial side, around the entire circumference. The protruding portion 28 has a fitting surface portion 29 provided on the outer peripheral surface of the one axial side portion, and a step surface 30 that bends radially outward from the end on the other axial side of the fitting surface portion 29 and faces the one axial side.

[0052] The flange element 22 has an inner diameter side circular ring portion 17 , a cylindrical portion 18 , and an outer diameter side circular ring portion 19 .

[0053] The shaft member 21 and the flange element 22 are joined and fixed by welding or the like, with the radially inner portion of the side surface on the other axial side of the inner diameter side circular ring portion 17 abutting against the step surface 30 and the inner peripheral surface of the inner diameter side circular ring portion 17 being externally fitted onto the mating surface portion 29.

[0054] The friction clutch device 7 is provided between a pair of rotating members, the input member 4 and the rotating member 6, and switches between a connected mode in which the input member 4 and the rotating member 6 rotate together, and a disconnected mode in which the input member 4 and the rotating member 6 rotate relative to each other. When the friction clutch device 7 is incorporated between a rotating member and a fixed member, the friction clutch device 7 switches between a rotation mode in which the rotating member is allowed to rotate, and a braking mode in which the rotation of the rotating member is stopped or slowed down.

[0055] The friction clutch device 7 includes a first member 31, a second member 102, a retaining ring 32, a spacer 33, a retaining ring 34, a friction engagement portion 35, a pressure plate 36, an elastic member 37, and a pressure device 38. The friction engagement portion 35 has at least one first friction plate 45 and at least one second friction plate 46 that are arranged so as to be capable of relative displacement in the axial direction.

[0056] The first member 31 is coupled to one of a pair of rotating members, or to one of a rotating member and a fixed member, or is configured integrally with one of the members. In this example, the first member 31 is coupled and fixed to the input member 4, which is one of the pair of rotating members, and rotates integrally with the input member 4.

[0057] The first member 31 may have any structure depending on the application and configuration of the device to which the friction clutch device 7 is applied, as long as it can support the first friction plate 45 on its inner circumferential surface. In this example, the first member 31 has a stepped cylindrical shape. Specifically, the first member 31 is configured by connecting a large-diameter cylindrical portion 39 on one axial side and a small-diameter cylindrical portion 40 on the other axial side by a connecting cylindrical portion 41 having a substantially triangular cross-sectional shape.

[0058] The first member 31 is connected and fixed to the input member 4 so as to be rotatable integrally with the input member 4 by externally fitting and fixing the large diameter cylindrical portion 39 to a ring gear 95 that is integral with the input member 4 so as not to be rotatable relative to the ring gear 95 .

[0059] The first member 31 has a first inner peripheral uneven portion 42 on the inner peripheral surface of the small diameter cylindrical portion 40, which is made up of recesses and protrusions arranged alternately in the circumferential direction.

[0060] The second member 102 is coupled to the other of the pair of rotating members, or the other of the rotating member and the fixed member, or is configured integrally with the other member. The second member 102 is supported coaxially with the first member 31 and capable of relative rotation with respect to the first member 31. The second member 102 has an engaging groove 15 on its outer circumferential surface, and can have any structure depending on the application and configuration of the device to which the friction clutch device 7 is applied, as long as it can accommodate the pressure plate 36 and the retaining ring 32 and can support the second friction plate 46.

[0061] In this example, the second member 102 is the other of the pair of rotating members, and is constituted by a rotating member 6 having a locking groove 15 and a flange portion 16 on its outer circumferential surface.

[0062] The retaining ring 32 is fitted onto the rotating member 6, which is the second member 102. The spacer 33 and the retaining ring 34 are engaged with the engaging groove 15 provided in the rotating member 6 in order from one axial side, thereby preventing the retaining ring 32 from being displaced to one axial side.

[0063] The retaining ring 32 may have any structure depending on the configuration of the elastic member 37, as long as it can support one axial side of the elastic member 37 arranged between the retaining ring 32 and the pressing plate 36. In this example, the retaining ring 32 has a substantially L-shaped cross section. Specifically, the retaining ring 32 includes a base 43 having a substantially rectangular cross section, and a canopy 44 that protrudes from the radially outer portion of the base 43 along the entire circumference toward one axial side.

[0064] The base 43 is fitted onto the outer peripheral surface of the large diameter cylindrical portion 24 of the rotating member 6, in a portion located on the other axial side of the locking groove 15, without any radial play and allowing relative axial displacement.

[0065] The eaves portion 44 covers the spacer 33 and the retaining ring 34 that are locked in the locking groove 15. In other words, the inner peripheral surface of the eaves portion 44 abuts against the outer peripheral surface of the spacer 33 and the outer peripheral surface of the retaining ring 34, thereby preventing the spacer 33 and / or the retaining ring 34 from accidentally slipping out of the locking groove 15.

[0066] The spacer 33 is engaged with the locking groove 15, restricts the retaining ring 32 to a predetermined position in the axial direction, and, together with the retaining ring 34, functions to prevent the retaining ring 32 from being displaced to one side in the axial direction. In this example, the spacer 33 has a substantially rectangular cross-sectional shape and a substantially C-shaped end face when viewed from the axial direction. That is, the spacer 33 is configured as a segmented ring having a discontinuous portion at one location in the circumferential direction. This facilitates installation of the spacer 33 in the locking groove 15. Note that the cross-sectional shape of the spacer 33 may be any shape other than rectangular, as long as it is possible for the spacer 33 to be engaged with the locking groove 15 and the function is not impaired.

[0067] The spacer 33 has a radially inner portion disposed on one radial side of the inside of the locking groove 15. The spacer 33 also has a radially inner portion of its side surface on one axial side abutting against the inner surface of the locking groove 15 that faces the other axial side. This restricts the spacer 33 from being displaced toward one axial side.

[0068] The retaining ring 34 is engaged with the engagement groove 15 and functions to prevent the retaining ring 32 and the spacer 33 from displacing in one axial direction. The retaining ring 34 is disposed adjacent to the other axial side of the spacer 33. The retaining ring 34 has a substantially rectangular cross-sectional shape and a substantially C-shaped end face when viewed from the axial direction. That is, the retaining ring 34 is configured as a segmented ring having a discontinuous portion at one location in the circumferential direction. This facilitates installation of the retaining ring 34 in the engagement groove 15. Note that the cross-sectional shape of the retaining ring 34 may be any shape other than rectangular, as long as it is possible for the retaining ring 34 to be engaged with the engagement groove 15 and its function is not impaired.

[0069] The retaining ring 34 has a radially inner portion disposed inside the locking groove 15. The retaining ring 34 has a radially outer portion of its side surface on the other axial side abutted against a side surface on one axial side of the base 43, and its side surface on one axial side abutted against a side surface on the other axial side of the spacer 33. In other words, the retaining ring 34 is sandwiched in the axial direction between the side surface on one axial side of the base 43 and the side surface on the other axial side of the spacer 33.

[0070] The friction engagement portion 35 has at least one first friction plate 45 and one second friction plate 46 supported to allow relative axial displacement. The at least one first friction plate 45 is supported on the inner circumferential surface of the first member 31. The at least one second friction plate 46 is supported on the outer circumferential surface of the second member 102 to allow relative axial displacement with respect to the at least one first friction plate 45.

[0071] For example, the friction engagement portion 35 can be configured to support at least one first friction plate 45 on the inner circumferential surface of the first member 31 so as to prevent axial displacement, and to support at least one second friction plate 46 on the outer circumferential surface of the second member 102 so as to allow axial displacement. Alternatively, the friction engagement portion 35 can be configured to support at least one first friction plate 45 on the inner circumferential surface of the first member 31 so as to allow axial displacement, and to support at least one second friction plate 46 on the outer circumferential surface of the second member 102 so as to prevent axial displacement.

[0072] Alternatively, the friction engagement portion 35 can be configured to support at least one first friction plate 45 on the inner circumferential surface of the first member 31 so as to be capable of axial displacement, and to support at least one second friction plate 46 on the outer circumferential surface of the second member 102 so as to be capable of axial displacement. However, even in this case, one of the at least one first friction plate 45 and the at least one second friction plate 46 can be supported so as not to be capable of axial displacement with respect to the first member 31 or the second member 102.

[0073] In this example, the friction engagement portion 35 is configured by stacking a plurality of first friction plates 45 and a plurality of second friction plates 46 alternately.

[0074] In this example, the first friction plate 45 has a substantially hollow circular end face shape when viewed in the axial direction. The first friction plate 45 has a first outer circumferential uneven portion 47 on its outer circumferential surface, which is formed by alternately arranging recesses and protrusions in the circumferential direction. The first outer circumferential uneven portion 47 engages with the first inner circumferential uneven portion 42 of the first member 31, thereby supporting the first friction plate 45 so as to be able to move axially with respect to the small-diameter cylindrical portion 40 of the first member 31 but not to rotate relative to it.

[0075] In this example, the second friction plate 46 has a substantially hollow circular end face shape when viewed in the axial direction. The second friction plate 46 has a second inner peripheral uneven portion 48 on its inner peripheral surface, which is formed by alternately arranging recesses and protrusions in the circumferential direction. The second inner peripheral uneven portion 48 is engaged with a second outer peripheral uneven portion provided on the outer peripheral surface of the cylindrical portion 18 of the rotating member 6, which is the second member, so that the second friction plate 46 is supported so as to be able to move axially with respect to the cylindrical portion 18 of the rotating member 6 but not to rotate relative to it.

[0076] The second friction plate 46 located furthest to the other axial side among the second friction plates 46 has a protrusion portion 49 around its entire circumference that protrudes from the radial middle portion of the side surface on the other axial side toward the other axial side, and the tip of the protrusion portion 49 abuts against the side surface on one axial side of the outer diameter side circular ring portion 19 of the rotating member 6, thereby preventing displacement to the other axial side.

[0077] The friction engagement portion 35 may include a return spring that elastically biases the first friction plate 45 and the second friction plate 46 in a direction separating them from each other.

[0078] The pressure plate 36 faces one axial side surface of the friction plate (the second friction plate 46 in the illustrated example) that is located furthest axially from the first friction plate 45 and the second friction plate 46, and is fitted onto the rotating member 6, which is the second member 102, so as to be capable of axial movement toward and away from the friction plate located furthest axially from the friction plate that is located furthest axially from the first friction plate.

[0079] The pressure plate 36 can have any structure depending on the configuration and arrangement of the friction engagement portion 35, the elastic member 37, and the pressing device 38, as long as it has a structure on one axial side that supports the other axial side of the elastic member 37 arranged between the retaining ring 32 and the pressure plate 36 and is biased by the elastic member 37, and a structure on the other axial side that is pressed toward one axial side by the pressing device 38.

[0080] In this example, the pressure plate 36 comprises a circular ring portion 50 having an end face shape that is approximately hollow and circular when viewed from the axial direction, and a cylindrical portion 51 that is bent from the radially outer end of the circular ring portion 50 toward the other axial side.

[0081] The circular ring portion 50 is fitted onto the axially intermediate portion of the large-diameter cylindrical portion 24 of the rotating member 6 so as to allow relative axial displacement. The radially inner end of the side surface on the other axial side of the circular ring portion 50 faces the side surface on one axial side of the protruding portion 28. This prevents excessive displacement of the pressing plate 36 toward the other axial side.

[0082] The cylindrical portion 51 has an end surface on the other axial side opposed to a side surface on one axial side of the second friction plate 46 located closest to one axial side.

[0083] The elastic member 37 is sandwiched between the retaining ring 32 and the pressure plate 36, and elastically biases the pressure plate 36 toward the other axial direction. That is, the elastic member 37 applies elastic force to the first friction plate 45 and the second friction plate 46 in a direction in which they press against each other by pressing the second friction plate 46, which is located furthest to one side, toward the other axial direction using the pressure plate 36.

[0084] The elastic member 37 can be composed of one or more disc springs 52, or one or more torsion coil springs. In this example, the disc spring 52 is used as the elastic member 37, and is composed of two disc springs 52 stacked in series in two stages. Specifically, the elastic member 37 is composed of two disc springs 52 stacked in opposite axial directions so that their large-diameter ends face each other.

[0085] However, the two disc springs 52 may be stacked in opposite axial directions with their smaller diameter ends facing each other, or may be stacked in two stages in parallel. Alternatively, the elastic member 37 may be composed of one disc spring or three or more disc springs. When the elastic member is composed of three or more disc springs, the disc springs may be stacked in series, in parallel, or in a combination of series and parallel stacking.

[0086] In the friction clutch device 7 of this example, the elastic member 37 that applies elastic force to the first friction plate 45 and the second friction plate 46 in the direction of pressing them against each other is sandwiched between the pressure plate 36 and the retaining ring 32 that is fitted onto the rotating member 6, and the spacer 33 and the retaining ring 34 that are engaged with the engaging groove 15 of the rotating member 6 prevent the retaining ring 32 from being displaced to one side in the axial direction.

[0087] 9(a) to 9(d) will be used to explain a method of assembling the friction clutch device 7, i.e., a method of assembling the pressure plate 36, elastic member 37, retaining ring 32, snap ring 34, and spacer 33 to the rotating member 6, which is the second member 102. The assembly method of the friction clutch device 7 includes a temporary assembly step, a measurement step, and a spacer assembling step.

[0088] First, in the preliminary assembly process shown in FIG. 9( a), the pressing plate 36, the elastic member 37, and the retaining ring 32 are fitted onto the rotating member 6 (second member 102), in this example, onto the large-diameter cylindrical portion 24 of the rotating member 6, in that order from the other axial side, and the retaining ring 34 is engaged with the engaging groove 15.

[0089] Next, in the measurement process shown in Figure 9 (b), a load F of a predetermined magnitude facing the other axial side is applied to the end face on one axial side of the retaining ring 32, thereby displacing the retaining ring 32 to the other axial side, and the displacement amount Δd of the retaining ring 32 to the other axial side is measured.

[0090] Specifically, a large-diameter pressing surface 100 provided at the tip of a cylindrical pressing jig 99 presses against one axial end face of the overhang portion 44 of the pressing ring 32 with a predetermined load F, thereby displacing the pressing ring 32 toward the other axial side against the elastic force of the elastic member 37. The displacement Δd of the pressing ring 32 is measured based on the stroke of the pressing jig 99.

[0091] The magnitude of the load F pressing against the retaining ring 32 is determined appropriately according to the magnitude of the pressing force to be applied between the first friction plate 45 and the second friction plate 46 based on the elasticity of the elastic member 37 when the force pressing the pressure plate 36 toward one axial side by the pressing device 38 is released.

[0092] 9(c), a spacer 33 having the same thickness as the displacement Δd is engaged from one axial side into the engagement groove 15. Specifically, from among a plurality of types of spacers 33 having different axial thicknesses T, a spacer 33 having the same axial thickness T (= Δd) as the displacement Δd of the retaining ring 32 measured in the measurement step is selected, and the spacer 33 is engaged from one axial side into the engagement groove 15.

[0093] More specifically, the spacer 33 is elastically expanded in diameter and fitted onto an end of the large-diameter cylindrical portion 24 that is located on one axial side of the locking groove 15. Then, the side surface on one axial side of the spacer 33 is pressed toward the other axial side by a small-diameter pressing surface 101 provided at the tip of a pressing jig 99. When the axial positions of the spacer 33 and the locking groove 15 match, the spacer 33 elastically returns to its original shape (reduced in diameter), and as shown in FIG. 9D, the spacer 33 is locked into the locking groove 15.

[0094] The cost of preparing multiple types of spacers 33 with different axial thicknesses T can be kept lower than the cost of preparing multiple types of disc springs with different free heights. Therefore, according to the friction clutch device 7 of this example and the assembly method thereof, it is easier to appropriately adjust the pressing force of the elastic member 37 while keeping manufacturing costs lower than the conventional friction clutch device described in WO 2022 / 074958.

[0095] Furthermore, in the assembly method of the friction clutch device 7 of this example, it is not necessary to measure the axial distance between the surface of the inner surface of the locking groove 15, which has a smaller axial width and faces the other axial side, and the end face on one axial side of the second member, the rotating member 6. Therefore, the assembly work can be made easier compared to the prior invention shown in Figures 10(a) to 10(d).

[0096] Furthermore, in the method of assembling the friction clutch device 7 of this example, it is possible to select a spacer 33 having an appropriate axial thickness T simply by measuring the amount of displacement Δd of the retaining ring 32 toward the other axial side when a predetermined load F is applied. This makes it possible to reduce the number of steps required to assemble the friction clutch device 7, thereby reducing manufacturing costs.

[0097] A feature of the friction clutch device 7 of this embodiment and its assembly method is that the axial thickness of the spacer 33 is adjusted so that the magnitude of the pressing force to be applied between the first friction plate 45 and the second friction plate 46 based on the elasticity of the elastic member becomes a desired magnitude. Therefore, as long as the features of this embodiment can be realized, the cross-sectional shape and axial thickness of the spacer 33 and the cross-sectional shape and axial thickness of the retaining ring are not particularly limited.

[0098] For example, the spacer 33 and the retaining ring 34 may be made of the same material, or different materials. Specifically, the cross-sectional shape of the spacer 33 and the cross-sectional shape of the retaining ring 34 may be the same as or different from each other. Furthermore, the thickness of the spacer 33 may be the same as the axial thickness of the retaining ring 34, or may be different from the axial thickness of the retaining ring 34. The spacer 33 may also be made up of a plurality of spacers 33.

[0099] The pressing device 38 presses the pressing plate 36 toward one side in the axial direction. The pressing device 38 includes at least a pressing member 73 capable of pressing the pressing plate 36 and a mechanism for displacing the pressing member 73 in the axial direction.

[0100] In this example, the pressing device 38 includes a cam device 53 , an electric actuator 54 , a pressing member 73 , and a thrust bearing 74 .

[0101] The cam device 53 includes a driving cam 55 , a driven cam 56 , and a plurality of rolling elements 57 .

[0102] 8, in this example, rollers are used as the rolling elements 57, and the rolling elements 57 are supported so as to be able to rotate (spin) freely around a rotation axis C that faces in a radial direction from the central axis of the driven cam 56. In order to make it easier to understand the invention, the cam device 53 is shown schematically in FIGS.

[0103] As shown in Fig. 7, the drive cam 55 has a drive cam surface 58 on the radially inner portion of one axial side surface, in which an equal number of recesses 58a and protrusions 58b are arranged alternately in the circumferential direction. The drive cam 55 is supported by a support member 60, a bearing device 14, and a radial bearing 61 so as to be rotatable relative to the rotating member 6. Note that the support member 60 and the bearing device 14 are not shown in Figs. 1 to 2(b).

[0104] The support member 60 includes a circular ring portion 83 having a hollow circular end face shape when viewed in the axial direction, and a cylindrical portion 84 bent from the radially inner end of the circular ring portion 83 toward one side in the axial direction.

[0105] The support member 60 is supported and fixed to the fixed portion 70 by bolts (not shown) that are inserted into or screwed into mounting holes 98 provided at a plurality of locations in the circumferential direction of the circular ring portion 83 .

[0106] The bearing device 14 is composed of a double-row ball bearing and includes an inner ring 85 fitted onto the second small diameter cylindrical portion 26 of the rotating member 6, an outer ring 86 fitted onto the cylindrical portion 84 of the support member 60, and a plurality of rolling elements 87 arranged to roll freely between the inner ring 85 and the outer ring 86.

[0107] The radial bearing 61 is composed of an angular ball bearing and includes an inner ring 88 fitted onto the cylindrical portion 84 of the support member 60, an outer ring 89 fitted onto the drive cam 55, and a plurality of balls 90 arranged to roll freely between the inner ring 88 and the outer ring 89.

[0108] In this example, the drive cam 55 has wheel teeth 62, which are helical gears, on its outer circumferential surface, and also has pin portions 63 that protrude toward one axial direction at multiple locations (three locations in the illustrated example) in the circumferential direction at the radially middle portion of its side surface on one axial side. The tip portions of the pin portions 63 are engaged (fitted with play) with engagement holes provided in a select plate 93 that constitutes the engagement device 8. This causes the drive cam 55 and the select plate to rotate integrally (at the same speed and in the same direction).

[0109] As shown in FIG. 8 , the driven cam 56 is configured as a hollow circular plate, and has rectangular holes 64 penetrating in the axial direction at a plurality of circumferential locations (three locations in the illustrated example) in a radially intermediate portion. The driven cam 56 also has support plate portions 65 a, 65 b, each having a substantially semicircular plate shape, protruding from both radially opposite sides of the rectangular holes 64 toward the other axial direction. Each of the radially outer support plate portions 65 a has a support hole 66, which is a circular hole penetrating in the radial direction, and each of the radially inner support plate portions 65 b has a support recess 67, which has a circular opening, on its radially outer surface. The driven cam 56 is disposed around the rotating member 6 so as to be displaceable only in the axial direction. Specifically, the driven cam 56 is supported axially displaceable relative to the fixed portion 70 by spline-engaging a female spline portion 68 provided on the inner peripheral surface with a male spline portion 69 provided on the outer peripheral surface of a cylindrical portion 84 of the support member 60, which is supported and fixed to the fixed portion 70.

[0110] Each of the multiple rolling elements 57 has a cylindrical shape and is rotatably supported on the support plate portions 65a, 65b via a columnar support shaft 71 and multiple rollers 72. That is, one axial end of the support shaft 71 (the outer end in the radial direction centered on the central axis of the driven cam 56) is fitted and fixed in the support hole 66 of the radially outer support plate portion 65a, and the other axial end of the support shaft 71 (the inner end in the radial direction centered on the central axis of the driven cam 56) is fitted and fixed in the support recess 67 of the radially inner support plate portion 65b. The multiple rollers 72 are rollably sandwiched between the inner circumferential surface of the rolling element 57 and the outer circumferential surface of the axially middle portion of the support shaft 71. As a result, the rolling element 57 is supported by the driven cam 56 so as to be able to rotate (spin) around a rotation axis C that faces in the radial direction centered on the central axis of the driven cam 56.

[0111] 6, with rolling element 57 supported by driven cam 56, most of rolling element 57 is disposed inside rectangular hole 64 and between support plate portions 65a, 65b. The other axial end of the outer circumferential surface of each rolling element 57 is in rolling contact with drive cam surface 58 provided on one axial side of drive cam 55.

[0112] Alternatively, the rolling elements 57 constituting the cam device 53 may be balls. In this case, in addition to or instead of the driving cam surface provided on one axial side of the driving cam, a driven cam surface is formed on the other axial side of the driven cam, with the same number of recesses and protrusions alternately arranged in the circumferential direction.

[0113] In the cam device 53, as the driving cam 55 rotates, the amount by which the rolling element 57 rides up from the bottom of the recess 58a that constitutes the driving cam surface 58 increases or decreases, thereby displacing the driven cam 56 in the axial direction.

[0114] The driven cam 56 presses the pressure plate 36 toward one side in the axial direction via the pressure member 73 and the thrust bearing 74 .

[0115] The pressing member 73 has a base 75 and a plurality of pressing arms 76 .

[0116] The base portion 75 has an end face shape that is generally hollow and circular when viewed in the axial direction. The base portion 75 is fitted onto the medium-diameter cylindrical portion 25 of the rotating member 6 without any play in the radial direction and so as to allow relative displacement in the axial direction.

[0117] Each pressing arm 76 protrudes toward one axial side from the radially outer end of the base 75. Each pressing arm 76 is inserted into a through-hole 20 provided in the inner diameter side circular ring portion 17, and its tip end surface faces a radially intermediate portion of the side surface on the other axial side of the circular ring portion 50 that constitutes the pressing plate 36.

[0118] The thrust bearing 74 is configured by arranging a plurality of rolling elements 78 freely rollably between a pair of raceways 77 a, 77 b that are coaxially arranged and spaced apart in the axial direction. The thrust bearing 74 is arranged between a side surface on one axial side of the driven cam 56 and a side surface on the other axial side of the base 75 of the pressing member 73.

[0119] In the friction clutch device 7 of this example, the pressing device 38 includes the thrust bearing 74, and therefore includes a preload applying member 79 for applying a preload to the thrust bearing 74, regardless of the axial dimension of the cam device 53. The preload applying member 79 is made up of one or more disc springs or one or more torsion coil springs. In the example shown in the figure, the preload applying member 79 is made up of multiple disc springs.

[0120] The preload applying member 79 is sandwiched in an elastically compressed state between a side surface on one axial direction side of the base portion 75 of the pressing member 73 and an end surface on the other axial direction side of the large-diameter cylindrical portion 24 of the rotating member 6. The preload applying member 79 elastically attempts to restore its original shape, thereby elastically pressing the pressing member 73 toward the other axial direction side. This applies a preload to the thrust bearing 74 and prevents the thrust bearing 74 from falling out from between the driven cam 56 and the pressing member 73.

[0121] The electric actuator 54 rotates the drive cam 55. In this example, the electric actuator 54 includes an electric motor 80 and a reducer 81. The reducer 81 is configured by meshing a worm 82, which is rotated by the electric motor 80, with wheel teeth 62 provided on the outer circumferential surface of the drive cam 55.

[0122] However, instead of the combination of the electric actuator 54 and the reducer 81, the mechanism for rotating the drive cam 55 can be configured such that a spur gear or bevel gear provided on the output shaft of the electric motor meshes with a spur gear or bevel gear provided on the drive cam 55, or a belt or chain is stretched between the output shaft of the electric motor and the drive cam 55.

[0123] Furthermore, as the cam device 53, instead of the combination of the driving cam 55, driven cam 56, and rolling body 57, it is also possible to use a cam device in which the driving cam surface provided on the driving cam and the driven cam surface provided on the driven cam are directly engaged (slid) with each other, or a cam device having a driven cam that has a guide groove that extends circumferentially on its outer peripheral surface and changes in the axial direction, and a driving cam that has an engaging protrusion that engages with the guide groove to enable displacement along the guide groove.

[0124] Alternatively, instead of the combination of the cam device 53, the electric actuator 54, and the thrust bearing 74 as the pressing device 38, the pressing member 73 may be formed of a piston, and a hydraulic cylinder device, a gas pressure cylinder device (including a pneumatic cylinder device), or the like may be used as a mechanism for displacing the pressing member 73 in the axial direction.

[0125] By controlling the pressing device 38, the friction clutch device 7 switches between a connection mode in which the first member 31 and the second member 102 (i.e., the rotating member 6) rotate integrally and a disconnection mode in which the first member 31 and the rotating member 6 rotate relatively to each other. That is, by releasing the force pressing the pressing plate 36 toward one axial direction by the pressing device 38, the first friction plates 45 and the second friction plates 46 are pressed against each other based on the elastic force of the elastic member 37, thereby switching to the connection mode in which the first member 31 and the rotating member 6 (i.e., the second member 102) rotate integrally. By pressing the pressing plate 36 toward one axial direction by the pressing device 38, the force pressing the first friction plates 45 and the second friction plates 46 against each other based on the elastic force of the elastic member 37 is released, thereby switching to the disconnection mode in which the first member 31 and the rotating member 6 (i.e., the second member 102) rotate relatively to each other.

[0126] In this example, switching between the connection mode and the disconnection mode is performed by controlling the power supply to the electric motor 80 and adjusting the rotation phase of the drive cam 55 .

[0127] More specifically, to switch the friction clutch device 7 to the engagement mode, the electric motor 80 is energized to rotate the drive cam 55, thereby reducing the amount by which the rolling elements 57 ride up from the bottom of the recess 58a of the drive cam surface 58. This causes the driven cam 56 to release the force pressing the pressure plate 36 toward one axial direction via the pressure member 73 and the thrust bearing 74. When the force pressing the pressure plate 36 toward one axial direction is released, the elastic restoring force of the elastic member 37 presses the pressure plate 36, the pressure member 73, and the thrust bearing 74 toward the other axial direction, and the pressure plate 36 presses the second friction plate 46, which is closest to one axial direction, toward the other axial direction. As a result, the first friction plate 45 and the second friction plate 46 press against each other, the friction clutch device 7 is engaged, and the first member 31 and the rotating member 6 rotate integrally.

[0128] To switch the friction clutch device 7 to the disengagement mode, the electric motor 80 is energized to rotate the drive cam 55, thereby increasing the amount by which the rolling elements 57 climb above the bottom of the recess 58a of the drive cam surface 58. This causes the driven cam 56 to press the pressure plate 36 toward one axial direction via the pressure member 73 and thrust bearing 74, elastically contracting the axial dimension of the elastic member 37 and releasing the force pressing the first friction plate 45 and the second friction plate 46 against each other. As a result, the gap between the first friction plate 45 and the second friction plate 46 increases, the friction clutch device 7 is disengaged, and the first member 31 and the rotating member 6 become rotatable relative to each other.

[0129] The engagement device 8 is provided between the fixed portion 70 and the rotating member 6, and switches between a rotatable state and an unrotatable state of the rotating member 6 relative to the fixed portion 70. In this example, the engagement device 8 is provided between the inner circumferential surface of the fixed portion 70 and the outer diameter side circular ring portion 19 of the rotating member 6.

[0130] The engagement device 8 can be configured, for example, as a mesh or friction clutch (brake device) whose mode can be switched by an actuator. The actuator for switching the clutch between engaged and disengaged states is not particularly limited, and a hydraulic actuator, an electromagnetic actuator, or the like can be used. In this example, the engagement device 8 is configured so that its mode can be switched based on the rotation of the drive cam 55 that constitutes the pressing device 38.

[0131] The engagement device 8 comprises an outer diameter side member 91 fitted and fixed to the inside of the fixed portion 70, an inner diameter side member 92 fitted and fixed to the outside of the outer diameter side circular ring portion 19, at least one engagement pin (not shown), and a select plate 93.

[0132] The engagement pin is releasably bridged between the outer diameter side member 91 and the inner diameter side member 92. In this example, the engagement pin protrudes radially inward from the inner peripheral surface of the outer diameter side member 91 and is supported in a state in which it is given an elastic force directed radially inward. The inner diameter side member 92 also has an engagement recess on its outer peripheral surface that can engage with the tip of the engagement pin.

[0133] The select plate 93 has engagement holes that open at multiple locations in the circumferential direction on the side surface on the other axial side. The tip ends of the pins 63 provided on the drive cam 55 are fitted into each engagement hole. This allows the select plate 93 to rotate integrally with the drive cam 55 (in the same direction and at the same speed).

[0134] The select plate 93 has a mode select portion which is a concave and convex portion in the circumferential direction.

[0135] The engagement device 8 switches between a state in which the outer diameter side member 91 and the inner diameter side member 92 are rotatable relative to each other and a state in which they are not, based on the rotation of the select plate 93. That is, based on the rotation of the select plate 93, the convex portion constituting the mode select section pushes the engagement pin radially outward, thereby disengaging the engagement pin from the engagement recess, thereby switching the engagement device 8 to the disconnection mode. This allows rotation of the inner diameter side member 92 relative to the outer diameter side member 91 and allows rotation of the rotating member 6 relative to the fixed part 70. On the other hand, based on the rotation of the select plate 93, the convex portion constituting the mode select section is moved to a position circumferentially offset from the tip of the engagement pin, thereby engaging the engagement pin with the engagement recess, thereby switching the engagement device 8 to the connection mode. This prevents rotation of the inner diameter side member 92 relative to the outer diameter side member 91 and prevents rotation of the rotating member 6 relative to the fixed part 70.

[0136] The planetary reduction mechanism 9 includes a sun gear 94, a ring gear 95, a carrier 96, and a plurality of planetary gears 97. That is, in this example, the planetary reduction mechanism 9 is configured by a single-pinion type planetary gear reducer.

[0137] However, when implementing the present disclosure, a double-pinion planetary gear mechanism can also be used as the planetary reduction mechanism. Alternatively, the planetary reduction mechanism can be configured as a friction roller mechanism having a sun roller, a ring roller arranged around the sun roller, and a planetary roller arranged radially between the sun roller and the ring roller, with the outer peripheral surface (rolling surface) frictionally engaged with the outer peripheral surface of the sun roller and the inner peripheral surface of the ring roller.

[0138] The sun gear 94 is rotatable integrally with the rotating member 6. In this example, the sun gear 94 is supported and fixed to the rotating member 6 so as to be rotatable integrally with the rotating member 6 by spline-engaging a female spline portion provided on the inner peripheral surface with a male spline portion provided on the outer peripheral surface of the first small-diameter cylindrical portion 23 of the rotating member 6.

[0139] The ring gear 95 is disposed around the sun gear 94 and coaxially therewith, and is rotatable integrally with the input member 4. In this example, the ring gear 95 is provided integrally with the inner peripheral surface of the other axial end of the input member 4.

[0140] The carrier 96 is disposed coaxially with the sun gear 94 and the ring gear 95, between the sun gear 94 and the ring gear 95 in the radial direction, and is rotatable integrally with the output member 5. In this example, the carrier 96 is provided integrally with the output member 5 at the other axial end of the output member 5.

[0141] Each of the plurality of planetary gears 97 meshes with the sun gear 94 and the ring gear 95, and is supported by the carrier 96 so as to be able to rotate (spin) around its own central axis.

[0142] The two-speed transmission 1 of this example controls the supply of electricity to the electric motor 80 and adjusts the rotational phase of the drive cam 55 to switch between the mode of the friction clutch device 7 and the mode of the engagement device 8, thereby being able to switch between a low reduction ratio mode in which the reduction ratio between the input member 4 and the output member 5 is small (reduction ratio is 1), and a high reduction ratio mode in which the reduction ratio is larger than that in the low reduction ratio mode.

[0143] <Low Reduction Ratio Mode> To switch the two-speed transmission 1 to the low reduction ratio mode, the friction clutch device 7 is switched to the connection mode, and the engagement device 8 is switched to the disconnection mode.

[0144] 2A, when the electric motor 80 is energized, the drive cam 55 is rotated in a direction that reduces the amount of the rolling elements 57 that climb up from the bottom of the recess 58a that constitutes the drive cam surface 58. This switches the friction clutch device 7 to the engagement mode, so that the input member 4 that is coupled and fixed to the first member 31 and the rotating member 6, which is the second member, rotate integrally. As a result, the sun gear 94 and ring gear 95 rotate integrally.

[0145] Furthermore, by adjusting the rotation phase of the selector plate 93 in accordance with the rotation of the drive cam 55, the engagement device 8 is switched to the disconnection mode, thereby allowing the rotation member 6 to rotate relative to the fixed part 70. As a result, the sun gear 94 is allowed to rotate relative to the fixed part 70.

[0146] In this low reduction ratio mode, the sun gear 94, ring gear 95, and carrier 96 rotate in the same direction and at the same speed, and the entire planetary reduction mechanism 9 rotates as a unit, in a so-called glued state. Therefore, the rotational torque of the input member 4 is transmitted directly to the output member 5 through the path shown by the thick line in Figure 2(a) without being increased (decelerated). In other words, in the low reduction ratio mode, the reduction ratio between the input member 4 and the output member 5 is 1.

[0147] <High Reduction Ratio Mode> To switch the two-speed transmission 1 to the high reduction ratio mode, the friction clutch device 7 is switched to the disengagement mode, and the engagement device 8 is switched to the engagement mode.

[0148] 2(b), when the electric motor 80 is energized, the drive cam 55 is rotated in a direction that increases the amount by which the rolling elements 57 climb up from the bottom of the recess 58a that constitutes the drive cam surface 58. This switches the friction clutch device 7 to a disengagement mode, allowing relative rotation between the input member 4 that is coupled and fixed to the first member 31 and the rotating member 6 that is the second member. As a result, the sun gear 94 and the ring gear 95 become relatively rotatable.

[0149] Furthermore, by adjusting the rotation phase of the selector plate 93 in accordance with the rotation of the drive cam 55, the engagement device 8 is switched to the connection mode, thereby preventing the rotation member 6 from rotating relative to the fixed part 70. As a result, the rotation of the sun gear 94 relative to the fixed part 70 is prevented.

[0150] In such a high reduction ratio mode, the rotational torque of the input member 4 is transmitted to the output member 5 via the path shown by the thick line in Figure 2 (b), i.e., the input member 4, the ring gear 95, the rotational motion of the planetary gear 97, the orbital motion of the planetary gear 97 based on meshing with the sun gear 94, and the path passing through the carrier 96.

[0151] In the high reduction ratio mode, the rotational torque of the input member 4 is increased by the planetary reduction mechanism 9 and transmitted to the output member 5. Note that the reduction ratio between the input member 4 and the output member 5 in the high reduction ratio mode is determined by the gear ratio between the ring gear 95 and the sun gear 94 (number of teeth of the ring gear 95 / number of teeth of the sun gear 94).

[0152] The two-speed transmission 1 can switch the reduction ratio between the input member 4 and the output member 5 between two levels, high and low, by switching the mode of the friction clutch device 7 and the mode of the engagement device 8. Specifically, in the region where the rotational torque input to the input member 4 is low speed and high torque, the two-speed transmission 1 is switched to the high reduction ratio mode, and in the region where the rotational torque input to the input member 4 is high speed and low torque, the two-speed transmission 1 is switched to the low reduction ratio mode. This makes it possible to make the acceleration performance and high-speed performance of electric vehicles and hybrid vehicles running using only an electric motor as a drive source similar to those of gasoline engine vehicles.

[0153] When switching the mode of the two-speed transmission 1, it is not necessary to switch the mode of the friction clutch device 7 and the mode of the engagement device 8 completely simultaneously, and these switches can be slightly delayed or moved forward. In other words, the engagement forces and timing of the friction clutch device 7 and the engagement device 8 can be appropriately adjusted so as to reduce the shift shock that accompanies the mode switch of the two-speed transmission 1.

[0154] The contents of the present disclosure have been described above using examples of specific embodiments. However, by referring to this disclosure, it is clear that a person skilled in the art can make various modifications and improvements that are within the scope of the present disclosure and equivalents thereof, and that fall within the scope of the present disclosure, and these ranges are also included in the scope of the present disclosure.

[0155] REFERENCE SIGNS LIST 1 Two-speed transmission 2 Drive source 3 Differential device 4 Input member 5 Output member 6 Rotating member 7 Friction clutch device 8 Engagement device 9 Planetary reduction mechanism 10 Output shaft 11 Drive gear 12 Input gear 13 Output gear 14 Bearing device 15 Locking groove 16 Flange portion 17 Inner diameter side circular ring portion 18 Cylindrical portion 19 Outer diameter side circular ring portion 20 Through hole 21 Shaft member 22 Flange element 23 First small diameter cylindrical portion 24 Large diameter cylindrical portion 25 Medium diameter cylindrical portion 26 Second small diameter cylindrical portion 27 Through hole 28 Protrusion 29 Fitting surface portion 30 Step surface 31 First member 32 Retaining ring 33 Spacer 34 Retaining ring 35 Friction engagement portion 36 Pressing plate 37 Elastic member 38 Pressing device 39 Large diameter cylindrical portion 40 Small diameter cylindrical portion 41 Connecting cylindrical portion 42 First inner peripheral uneven portion 43 Base portion 44 Eaves portion 45 First friction plate 46 Second friction plate 47 First outer peripheral uneven portion 48 Second inner peripheral uneven portion 49 Protrusion portion 50 Circular ring portion 51 Cylindrical portion 52 Disc spring 53 Cam device 54 Electric actuator 55 Drive cam 56 Driven cam 57 Rolling element 58 Drive cam surface 58a Recessed portion 58b Recessed portion 60 Support member 61 Radial bearing 62 Wheel tooth 63 Pin portion 64 Rectangular hole 65a, 65b Support plate portion 66 Support hole 67 Support recessed portion 68 Female spline portion 69 Male spline portion 70 Fixed portion 71 Support shaft 72 Roller 73 Pressing member 74 Thrust bearing 75 Base 76 Pressing arm 77a, 77b Raceway ring 78 Rolling element 79 Preload applying member 80 Electric motor 81 Reducer 82 Worm 83 Circular ring portion 84 Cylindrical portion 85 Inner ring 86 Outer ring 87 Rolling element 88 Inner ring 89 Outer ring 90 Ball 91 Outer diameter side member 92 Inner diameter side member 93 Select plate 94 Sun gear 95 Ring gear 96 Carrier 97 Planetary gear 98 Mounting hole 99 Pressing jig 100 Large diameter side pressing surface 101 Small diameter side pressing surface 102 Second member 200 Disc spring 201 Shaft member 202 Retaining ring 203 Pressing plate204 Locking groove 205 Retaining ring 206 Pressing jig

Claims

1. A friction clutch device comprising: a first member; a second member having a locking groove on an outer peripheral surface, supported coaxially with the first member and rotatable relative to the first member; a retaining ring externally fitted to the second member; a spacer and a retaining ring that are sequentially locked to the locking groove from one axial side and prevent displacement of the retaining ring toward one axial side; a friction engagement portion having at least one first friction plate supported on an inner peripheral surface of the first member and at least one second friction plate supported on an outer peripheral surface of the second member to allow axial relative displacement with respect to the at least one first friction plate; a pressing plate externally fitted to the second member, facing a side surface on one axial side of the friction plate located most on one axial side among the first friction plate and the second friction plate, and allowing axial movement away from the friction plate located most on one axial side; an elastic member sandwiched between the retaining ring and the pressing plate and elastically biasing the pressing plate toward the other axial side; and a pressing device that presses the pressing plate toward one axial side.

2. The friction clutch device according to claim 1, wherein the retaining ring has a base portion externally fitted to the second member and a flange portion protruding from a radially outer portion of the base portion toward one axial side and covering the periphery of the spacer and the retaining ring.

3. The friction clutch device according to claim 1 or 2, wherein the elastic member has a disc spring.

4. A method for assembling a friction clutch device according to any one of claims 1 to 3, comprising: a preliminary assembly step of externally fitting the pressing plate, the elastic member, and the retaining ring to the second member in this order from the other axial side, and locking the retaining ring to the locking groove; a measuring step of, after the preliminary assembly step, applying a load of a predetermined magnitude facing the other axial side to an end surface on one axial side of the retaining ring to displace the retaining ring toward the other axial side and measuring the amount of displacement of the retaining ring toward the other axial side; and a spacer assembly step of locking the spacer having the same thickness as the amount of displacement to the locking groove from one axial side.

Images