Abstract: A power transmission device has a pressure member (5) pressing drive-side clutch plates and driven-side clutch plates against each other or releasing a press-contact force. A clutch spring (10) urges the pressure member (5) in a direction so that the clutch plates are pressed against each other. A separate receiving member (11) is attached to the pressure member (5). A back-torque limiting cam reduces press-contact force between the clutch plates when the rotation speed of an output member exceeds the rotation speed of an input member. A rotation restricting portion (8a) restricting rotation, relative to the clutch member (4), of the pressure member (5) that has moved due to activation of the push rod (9). A clearance t is maintained between the pair of cam surfaces that constitute the back-torque limiting cam.

Abstract: A power transmission device has a back torque transmission cam that brings driving clutch plates 6 and driven clutch plates 7 into press contact with each other. A second clutch member 4b is moved when a rotational force is input to a first clutch member 4a via the output shaft 3. The pressure member 5 is located at a non-actuation position. A torque transmission portion transmits a rotational force transmitted to the second clutch member 4b to the first clutch member 4a not via the back torque transmission cam.

Abstract: A power transmission device has a back torque transmission cam that brings driving clutch plates 6 and driven clutch plates 7 into press contact with each other. This occurs by moving a second clutch member 4b when a rotational force is input to a first clutch member 4a, via the output shaft 3. A pressure member 5 is located at a non-actuation position. A back torque transmission cam can hold abutment between an interlocking member 9 and weight member 8 by moving the second clutch member 4b in a direction of being brought into proximity to the interlocking member 9.

Abstract: A power transmitting apparatus has a clutch member and a pressure member. The cam surfaces of the pressure-contact assist cam face each other. The cam surfaces of the back torque limiter cam face each other. A receiving portion for a clutch spring (10) on the pressure member (5) side has a receiving member (11) separate from the pressure member (5). A first cam surface (C1) and a second cam surface (C2), constituting the back torque limiter cam, are, respectively, formed on the receiving member (11) and the clutch member (4). A third cam surface (C3) and a fourth cam surface (C4), constituting the pressure-contact assist cam, are, respectively, formed on the pressure member (5) and the clutch member (4).

Abstract: 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.

Abstract: A power transmitting apparatus has a clutch member and a pressure member. The cam surfaces of the pressure-contact assist cam face each other. The cam surfaces of the back torque limiter cam face each other. A receiving portion for a clutch spring (10) on the pressure member (5) side has a receiving member (11) separate from the pressure member (5). A first cam surface (C1) and a second cam surface (C2), constituting the back torque limiter cam, are, respectively, formed on the receiving member (11) and the clutch member (4). A third cam surface (C3) and a fourth cam surface (C4), constituting the pressure-contact assist cam, are, respectively, formed on the pressure member (5) and the clutch member (4).

Abstract: A power transmitting apparatus has a clutch member and a pressure member. The cam surfaces of the pressure-contact assist cam face each other. The cam surfaces of the back torque limiter cam face each other. A receiving portion for a clutch spring (10) on the pressure member (5) side has a receiving member (11) separate from the pressure member (5). A first cam surface (C1) and a second cam surface (C2), constituting the back torque limiter cam, are, respectively, formed on the receiving member (11) and the clutch member (4). A third cam surface (C3) and a fourth cam surface (C4), constituting the pressure-contact assist cam, are, respectively, formed on the pressure member (5) and the clutch member (4).

Abstract: A power transmitting apparatus for transmitting or cutting-off the rotational driving power inputted to an input member to or from an output member by press-contacting or releasing the press-contacting force between driving-side clutch discs and driven-side clutch discs, wherein the power transmitting apparatus comprises interlocking members (e.g., a first member and second member) interlocking with the motion of the weight members from their radially inward positions to radially outward positions and movable toward a direction approaching to the pressure member; and elastic members interposed between the interlocking members and the pressure member and able to move the pressure member toward a direction for press-contacting the driving-side clutch discs and the driven-side clutch discs by urging the pressure member according to the movement of the interlocking members and also able to absorb the urging force of the pressure member applied to interlocking members when the actuating member is operated.

Abstract: A power transmitting apparatus has a clutch member and a pressure member. The cam surfaces of the pressure-contact assist cam face each other. The cam surfaces of the back torque limiter cam face each other. A receiving portion for a clutch spring (10) on the pressure member (5) side has a receiving member (11) separate from the pressure member (5). A first cam surface (C1) and a second cam surface (C2), constituting the back torque limiter cam, are, respectively, formed on the receiving member (11) and the clutch member (4). A third cam surface (C3) and a fourth cam surface (C4), constituting the pressure-contact assist cam, are, respectively, formed on the pressure member (5) and the clutch member (4).

Abstract: A power transmitting apparatus comprising a switching device for switching an urging device between an urging force applying position wherein an abutment between the other end of the urging device and the pressure member is kept to apply the urging force of urging device to the pressure member when the intermediate member is moved toward the pressure member, and an urging force cutting-off position wherein the other end of the urging device is separated from the pressure member to cut-off the urging force of urging device to the pressure member when the intermediate member is moved toward the pressure member. In some embodiments, the urging device is set at the urging force applying position while the intermediate member is stopped when the vehicle is stopped and the urging device is set at the urging force cutting-off position while the intermediate member is rotated when the vehicle is running.

Abstract: A power transmitting apparatus for transmitting or cutting-off the rotational driving power inputted to an input member to or from an output member by press-contacting or releasing the press-contacting force between driving-side clutch discs and driven-side clutch discs, wherein the power transmitting apparatus comprises interlocking members (e.g., a first member and second member) interlocking with the motion of the weight members from their radially inward positions to radially outward positions and movable toward a direction approaching to the pressure member; and elastic members interposed between the interlocking members and the pressure member and able to move the pressure member toward a direction for press-contacting the driving-side clutch discs and the driven-side clutch discs by urging the pressure member according to the movement of the interlocking members and also able to absorb the urging force of the pressure member applied to interlocking members when the actuating member is operated.

Abstract: A power transmitting apparatus comprising a switching device for switching an urging device between an urging force applying position wherein an abutment between the other end of the urging device and the pressure member is kept to apply the urging force of urging device to the pressure member when the intermediate member is moved toward the pressure member, and an urging force cutting-off position wherein the other end of the urging device is separated from the pressure member to cut-off the urging force of urging device to the pressure member when the intermediate member is moved toward the pressure member. In some embodiments, the urging device is set at the urging force applying position while the intermediate member is stopped when the vehicle is stopped and the urging device is set at the urging force cutting-off position while the intermediate member is rotated when the vehicle is running.