A power transmission device has an interlocking member 9 moving a pressure member 5 from an inactive position to an active position. A release spring (m) applies an urging force, while allowing movements of the interlocking member 9 and the pressure member 5, until drive-side clutch plates 6 and driven-side clutch plates 7 reach an engaged state before the drive-side clutch plates 6 and the driven-side clutch plates 7 are pressed against each other. A clutch spring 11 is compressed in a process where the interlocking member 9 moves after the drive-side clutch plates 6 and the driven-side clutch plates 7 have reached the engaged state. The clutch spring applying a press-contact force between the drive-side clutch plates 6 and the driven-side clutch plates 7 while allowing movements of the interlocking member 9 and the pressure member 5. The set load of the clutch spring 11 is set to be smaller than the maximum load of the release spring (m).

A power transmission device has an interlocking member 9 moving a pressure member 5 from an inactive position to an active position. A release spring (m) applies an urging force, while allowing movements of the interlocking member 9 and the pressure member 5, until drive-side clutch plates 6 and driven-side clutch plates 7 reach an engaged state before the drive-side clutch plates 6 and the driven-side clutch plates 7 are pressed against each other. A clutch spring 11 is compressed in a process where the interlocking member 9 moves after the drive-side clutch plates 6 and the driven-side clutch plates 7 have reached the engaged state. The clutch spring applying a press-contact force between the drive-side clutch plates 6 and the driven-side clutch plates 7 while allowing movements of the interlocking member 9 and the pressure member 5. The set load of the clutch spring 11 is set to be smaller than the maximum load of the release spring (m).

A power transmission device has an interlocking member 9 moving a pressure member 5 from an inactive position to an active position. A release spring (m) applies an urging force, while allowing movements of the interlocking member 9 and the pressure member 5, until drive-side clutch plates 6 and driven-side clutch plates 7 reach an engaged state before the drive-side clutch plates 6 and the driven-side clutch plates 7 are pressed against each other. A clutch spring 11 is compressed in a process where the interlocking member 9 moves after the drive-side clutch plates 6 and the driven-side clutch plates 7 have reached the engaged state. The clutch spring applying a press-contact force between the drive-side clutch plates 6 and the driven-side clutch plates 7 while allowing movements of the interlocking member 9 and the pressure member 5. The set load of the clutch spring 11 is set to be smaller than the maximum load of the release spring (m).

A power transmission device has an interlocking member 9 moving a pressure member 5 from an inactive position to an active position. A release spring (m) applies an urging force, while allowing movements of the interlocking member 9 and the pressure member 5, until drive-side clutch plates 6 and driven-side clutch plates 7 reach an engaged state before the drive-side clutch plates 6 and the driven-side clutch plates 7 are pressed against each other. A clutch spring 11 is compressed in a process where the interlocking member 9 moves after the drive-side clutch plates 6 and the driven-side clutch plates 7 have reached the engaged state. The clutch spring applying a press-contact force between the drive-side clutch plates 6 and the driven-side clutch plates 7 while allowing movements of the interlocking member 9 and the pressure member 5. The set load of the clutch spring 11 is set to be smaller than the maximum load of the release spring (m).

A transmission device has a clutch spring (8). The clutch spring (8) can generate rotational resistance that occurs when a pressure member (5) rotates relative to a clutch member (4) due to clearance between cam surfaces of a press-contact assisting cam or a back torque limiting cam. Thus, one end (8a) of the clutch spring (8) slides on a surface (10a) of a restricting member 10. A side surface (8b) of the clutch spring (8) is held in the longitudinal direction.

A transmission device has a clutch spring (8). The clutch spring (8) can generate rotational resistance that occurs when a pressure member (5) rotates relative to a clutch member (4) due to clearance between cam surfaces of a press-contact assisting cam or a back torque limiting cam. Thus, one end (8a) of the clutch spring (8) slides on a surface (10a) of a restricting member 10. A side surface (8b) of the clutch spring (8) is held in the longitudinal direction.

A friction clutch for a drivetrain of a motor vehicle includes and input part, an output part, a spring device, a pressure pot, and a connecting means connecting the pressure pot to the inner-plate carrier. The input part includes an outer-plate carrier which is rotatable about an axis of rotation by a drive motor, and an outer plate rotationally fastened to the outer-plate carrier. The input part includes a rotor carrier, an inner-plate carrier separate from the rotor carrier, and an inner plate rotationally fastened to the inner-plate carrier. The spring device is for bracing the outer plate and the inner plate together with a pressing force to close the friction clutch. The connecting means includes an actuating surface via which the friction clutch can be actuated by an actuating device.

A friction clutch for a drivetrain of a motor vehicle includes and input part, an output part, a spring device, a pressure pot, and a connecting means connecting the pressure pot to the inner-plate carrier. The input part includes an outer-plate carrier which is rotatable about an axis of rotation by a drive motor, and an outer plate rotationally fastened to the outer-plate carrier. The input part includes a rotor carrier, an inner-plate carrier separate from the rotor carrier, and an inner plate rotationally fastened to the inner-plate carrier. The spring device is for bracing the outer plate and the inner plate together with a pressing force to close the friction clutch. The connecting means includes an actuating surface via which the friction clutch can be actuated by an actuating device.

Provided are a wet friction plate configured so that drag torque can be reduced while a manufacturing burden is reduced with a simple configuration, a wet multiplate clutch device including the wet friction plates, and a wet friction plate manufacturing method. A wet friction plate (200) includes friction members (210) provided on a flat plate annular core metal (201), having oil grooves (203), and made of a paper material. The friction members (210) include higher friction members (211) and lower friction members (212). The higher friction member (211) is formed such that the height thereof from a surface of the core metal (201) is higher than that of the lower friction member (212). In addition, the higher friction member (211) is formed with a less-elastically-deformable structure than that of the lower friction member (212). The lower friction member (212) is formed such that the height thereof from the surface of the core metal (201) is lower than that of the higher friction member (211). In addition, the lower friction member (212) is formed with a more-elastically-deformable structure than that of the higher friction member (211). The higher friction members (211) and the lower friction members (212) are alternately arranged along a circumferential direction on the core metal (201).

A power transmission device has a first clutch member 4a coupled to an output member 3. A second clutch member 4b has a plurality of driven-side clutch plates 7. A back-torque transmitting cam presses the drive-side clutch plates 6 and the driven-side clutch plates 7 against each other by moving the second clutch member 4b when a rotational force is input to the first clutch member 4a. A cushioning member 12 is interposed between the first clutch member 4a and the second clutch member 4b. The cushioning member 12, by being compressed, applies an urging force while allowing movements of an interlocking member 9 and a pressure member 5 in a process where the interlocking member 9 moves and the pressure member 5 moves from the inactive position toward the active position.