Multiple disc clutch apparatus

A multiple disc clutch apparatus comprising:

• a clutch outer member which is coupled to an input member;
• a clutch inner member which is fixed to an output shaft so as not to rotate with respect to the output shaft;
• a plurality of primary friction discs which are fixed to the clutch outer member so as not to rotate with respect to the clutch outer member;
• a plurality of secondary friction discs which are disposed alternately with the primary friction discs in an axial direction;
• a pressure plate, wherein the primary friction discs and the secondary friction discs are held between the clutch inner member and the pressure plate in the axial direction;
• a clutch center member which is provided between the clutch inner member and the pressure plate in the axial direction, wherein the secondary friction discs are fixed to the clutch center member so as not to rotate with respect to the clutch center member;
• and
• a cam mechanism adapted to axially move the primary friction discs and the secondary friction discs in a direction in which the primary friction discs and the secondary friction discs are brought into press contact or in a direction in which the primary friction discs and the secondary friction discs move away,
• wherein the cam mechanism comprises a pair of cam members including a projecting cam and a recess cam,
• wherein the pair of cam members are provided between the clutch inner member and the clutch center member,
• wherein contact surfaces of the projecting cam and the recess cam are formed into a curved surface,
• wherein one of the cam members which is disposed on a side of the clutch inner member is formed into an annular shape, and
• wherein said one of the cam members on the side of the clutch inner member extends in a radial direction, and an outer circumferential surface of said one of the cam members is brought into abutment with a cylindrical face on an inner circumferential surface of the clutch center member.