Patent ID: 8302752

Claim:
A multi-plate clutch comprising: a clutch outer member connected to an input member; a clutch inner member having a cylindrical portion and a pressure-applying plate portion, the cylindrical portion being coaxially disposed in the clutch outer member, and the pressure-applying plate portion being arranged integrally with one end of the cylindrical portion; a pressure-receiving plate fixed to an output member, and arranged opposite to the pressure-applying plate portion such that a plurality of driving friction plates and a plurality of driven friction plates interposed therebetween, wherein the plurality of driving friction plates are engaged with the clutch outer member so as not to rotate relative thereto, and the plurality of driven friction plates are engaged with the clutch inner member so as not to rotate relative thereto; a center cam having a disc portion disposed in a plane orthogonal to a rotation axis of the output member, the center cam being disposed inward in a radial direction of the cylindrical portion, and is fixed to the output member; an assist cam arranged opposite to one surface of the disc portion, and being operable to move the pressure-applying plate portion toward the pressure-receiving plate based an increase in driving force inputted from the input member; and a slipper cam arranged opposite to the other surface of the disc portion, and being operable to move the pressure-applying plate portion away from the pressure-receiving plate in accordance with an increase in back torque from the output member, wherein the assist cam and the slipper cam are formed of an identical material, and have substantially identical shapes; an outer circumference of the assist cam is splined to an inner circumference of the cylindrical portion of the clutch inner member such that the assist cam is operable to move in an axial direction relative to the clutch inner member; and an outer circumference of the slipper cam is splined to the inner circumference of the cylindrical portion of the clutch inner member such that at least an axial motion of the slipper cam relative to the clutch inner member away from the disc portion is limited.