Patent ID: 9631678
Date: 2017-04-25
CPC Classifications: F16D

Claim:
1. A clutch apparatus, comprising: a clutch outer connected to an input power member; a clutch inner having a first ring plate portion extending along a plane perpendicular to an axial line of an output power shaft and a plurality of boss portions extending in an axial direction from the first ring plate portion and connected in an interlocking relationship to the output power shaft; a plurality of driving friction plates configured to be engaged by the clutch outer; a plurality of driven friction plates disposed alternately with the driving friction plates and configured to be engaged by the clutch inner; a pressure receiving plate disposed in an opposing relationship to that one of the driving friction plates and the driven friction plates which is disposed at one end of the clutch inner along the axial direction and coupled to the clutch inner; a pressing plate cooperating with the pressure receiving plate to sandwich the driving friction plates and the driven friction plates therebetween; a movable cam member spline-coupled to the clutch inner against relative rotation but for axial movement; a fixed cam member fixed to the output power shaft so as to cooperate with the movable cam member to configure a cam mechanism and having a second ring plate portion which is opposed to the first ring plate portion and has a plurality of openings which are provided therein so as to allow the boss portions to penetrate the second ring plate portion therethrough; and a plurality of first clutch springs provided between a first spring receiving plate fixed to an end portion of the boss portions and the pressing plate and configured to bias the pressing plate so as to cooperate with the pressure receiving plate to contact the driving friction plates and the driven friction plates under pressure with each other therebetween; a swollen portion being provided integrally at a base portion of each of the boss portions in such a manner as to be swollen to opposite sides from the boss portion along a circumferential direction of the clutch inner such that, in a state in which a phase between the fixed cam member and the movable cam member is displaced from a correct phase, the swollen portion abuts with an end edge of the associated opening along a circumferential direction of the fixed cam member thereby to prevent insertion of the associated boss portion into the opening, wherein the plurality of boss portions each have a cylindrical shape with an axis extending in the axial direction, and wherein the swollen portion protrudes from a side of the cylindrical shape of the respective boss portion in the circumferential direction of the clutch inner.