Patent ID: 9689439
Date: 2017-06-27
CPC Classifications: F16D

Claim:
1. A clutch device comprising: a first clutch member; a second clutch member; a third clutch member supported on the second clutch member in an axially movable and relatively rotatable manner; a first friction plate supported on the first clutch member in an axially movable and integrally rotatable manner; a second friction plate supported on the third clutch member in an axially movable and integrally rotatable manner, such that the second friction plate overlaps with the first friction plate; a pressure receiving plate mounted on the second clutch member in a state where the pressure receiving plate opposedly faces one side of an assembled body formed of the first friction plate and the second friction plate in a clutch axial direction; a pressurizing plate provided in a state where the pressurizing plate faces an opposite side of the assembled body in the clutch axial direction and is movable toward the pressure receiving plate in the clutch axial direction; a clutch spring which biases the pressurizing plate to a pressure receiving plate side; a slipper cam mechanism provided between the second clutch member and the third clutch member, and configured such that in a state where a back torque is applied to the third clutch member from the second clutch member, the slipper cam mechanism moves the third clutch member along with the pressurizing plate in the clutch axial direction to reduce the back torque transmitted to the first clutch member; and a movement restricting mechanism provided to the third clutch member which selectively limits movement of the third clutch member in the clutch axial direction, wherein the movement restricting mechanism is moved between movement restricting and movement non-restricting positions thereof by a centrifugal force generated by rotation of the third clutch member such that the movement restricting mechanism restricts axial movement of the third clutch member until a rotational speed of the third clutch member reaches a threshold value, but does not restrict the axial movement of the third clutch member when the rotational speed of the third clutch member exceeds the threshold value, and further including a power transmission shaft supporting the clutch device; a lock nut fixing the second clutch member to the power transmission shaft; and a washer member which forms the movement restricting portion arranged between the lock nut and the second clutch member, wherein the movement restricting mechanism includes a plunger which is advanceable and retractable between the movement restricting position of the movement restricting mechanism where the plunger overlaps with the washer member as viewed in an axial direction, and the movement non-restricting position of the movement restricting mechanism where the plunger does not overlap with the washer member as viewed in an axial direction, and the plunger contacts the washer member in the clutch axial direction when the movement restricting mechanism is in the movement restricting position thereof, thus restricting the movement of the third clutch member in the clutch axial direction, wherein the washer member has a washer-side contact surface which is inclined such that the closer to an outer peripheral side the washer-side contact surface is disposed with respect to an axially orthogonal plane, the farther away from an axial center of the plunger the washer-side contact surface is positioned, and the plunger has a plunger-side contact surface which is inclined so as to conform to the washer-side contact surface, and wherein the washer-side contact surface and the plunger-side contact surface are each formed into a stepped shape.