Abstract: A clutch device includes a slipper cam mechanism which releases a back torque by moving a clutch center in an axial direction, and a plunger mechanism provided to the clutch center. The plunger mechanism engages with a movement restricting portion until a rotational speed of the clutch center reaches a threshold value thus restricting the movement of the clutch center in the clutch axial direction, and the plunger mechanism is operated by a centrifugal force when the rotational speed of the clutch center exceeds the threshold value such that it disengages from the movement restricting portion.

Abstract: A clutch device includes a slipper cam mechanism which releases a back torque by moving a clutch center in an axial direction, and a plunger mechanism provided to the clutch center. The plunger mechanism engages with a movement restricting portion until a rotational speed of the clutch center reaches a threshold value thus restricting the movement of the clutch center in the clutch axial direction, and the plunger mechanism is operated by a centrifugal force when the rotational speed of the clutch center exceeds the threshold value such that it disengages from the movement restricting portion.

Abstract: A lubrication structure for a multi-speed transmission has a lubrication structure in which a gear shaft is provided with cam guide grooves in an inner cavity thereof. A lubricating oil is introduced into the inner cavity by way of oil feed introducing holes which are bored in one end portion of the gear shaft so as to provide communication between the inside and the outside of the gear shaft. The lubricating oil is led in the axial direction along the inner peripheral surface of the inner cavity by axial oil feed grooves formed by cutting along the inner peripheral surface of the inner cavity in parallel to the cam guide grooves. The lubricating oil is led out to the engagement switch-over mechanism by radial oil feed holes bored in radial directions so as to communicate with the axial oil feed grooves at axial-direction positions where pin members are located.

Abstract: An arrangement structure of a shifting actuator of an internal combustion engine mounted on a motorcycle is provided in which while the shifting actuator is provided externally of an engine case of the engine so as not to interfere with auxiliaries, it is protected without external protrusion and external appearance is kept satisfactory. An external wall of an engine case is partially inwardly recessed to form a recessed portion capable of accommodating a shifting actuator. An actuator body of the shifting actuator is disposed in the recessed portion. An attachment bracket attached to an end portion of the actuator body is fitted to a first fitting hole of an engine case outer lateral wall on the side of the recessed portion and is secured to the engine case outer wall. The motorcycle has a multistage transmission that can reduce its axial width to achieve compactness.

Abstract: In a multiple disc clutch apparatus 10, a cam member 41 which is disposed on a side of a clutch inner member 16 is formed into an annular shape. The cam member 41 extends in a radial direction so that an outer circumferential surface of the cam member 41 is brought into abutment with a cylindrical face 19d on an inner circumferential surface of a clutch center member 19.

Abstract: A vehicle clutch includes a clutch outer member, a clutch inner member, and a clutch center member movable in an axial direction between a first position and a second position. A cam mechanism is provided between the clutch inner and outer members. The cam mechanism generates an axial pulling force for moving the clutch center member to the first position when positive torque acts on the clutch inner member from the clutch center member.

Abstract: A lubrication structure for a multi-speed transmission has a lubrication structure in which a gear shaft is provided with cam guide grooves in an inner cavity thereof. A lubricating oil is introduced into the inner cavity by way of oil feed introducing holes which are bored in one end portion of the gear shaft so as to provide communication between the inside and the outside of the gear shaft. The lubricating oil is led in the axial direction along the inner peripheral surface of the inner cavity by axial oil feed grooves formed by cutting along the inner peripheral surface of the inner cavity in parallel to the cam guide grooves. The lubricating oil is led out to the engagement switch-over mechanism by radial oil feed holes bored in radial directions so as to communicate with the axial oil feed grooves at axial-direction positions where pin members are located.

Abstract: An arrangement structure of a shifting actuator of an internal combustion engine mounted on a motorcycle is provided in which while the shifting actuator is provided externally of an engine case of the engine so as not to interfere with auxiliaries, it is protected without external protrusion and external appearance is kept satisfactory. An external wall of an engine case is partially inwardly recessed to form a recessed portion capable of accommodating a shifting actuator. An actuator body of the shifting actuator is disposed in the recessed portion. An attachment bracket attached to an end portion of the actuator body is fitted to a first fitting hole of an engine case outer lateral wall on the side of the recessed portion and is secured to the engine case outer wall. The motorcycle has a multistage transmission that can reduce its axial width to achieve compactness.

Abstract: In a multiple disc clutch apparatus 10, a cam member 41 which is disposed on a side of a clutch inner member 16 is formed into an annular shape. The cam member 41 extends in a radial direction so that an outer circumferential surface of the cam member 41 is brought into abutment with a cylindrical face 19d on an inner circumferential surface of a clutch center member 19.

Abstract: A vehicle clutch includes a clutch outer member, a clutch inner member, and a clutch center member movable in an axial direction between a first position and a second position. A cam mechanism is provided between the clutch inner and outer members. The cam mechanism generates an axial pulling force for moving the clutch center member to the first position when positive torque acts on the clutch inner member from the clutch center member.