Patent ID: 9726228
Date: 2017-08-08
CPC Classifications: F16D

Claim:
1. A clutch with a back torque limiter, the clutch comprising: a housing which is provided with a drive plate to be movable in an axial direction and to which a rotary motive power is transmitted from a driving force source; a hub which transmits the rotary motive power to an output shaft; a sleeve which is provided with a driven plate to be movable in the axial direction and which transmits the rotary motive power from the housing to the hub when the driven plate is pressed against the drive plate; and a pressure disk which is movable in the axial direction and biases the drive plate and the driven plate toward the hub, and further comprising: a back torque limiter which moves the pressure disk in a direction away from the hub to reduce a biasing force on the drive plate and the driven plate when back torque is applied from the output shaft; a restricting apparatus which restricts movement of the pressure disk in the direction away from the hub when a number of rotations of the output shaft is less than a predetermined value, wherein; the hub and the sleeve are relatively movable in a rotation direction and the axial direction; the hub and the sleeve relatively move in the rotation direction when the back torque is applied from the output shaft; the back torque limiter moves the sleeve in the direction away from the hub according to the relative movement in the rotation direction of the hub and the sleeve, and brings the sleeve into abutment against the pressure disk to press the pressure disk to thereby move the pressure disk in the direction away from the hub; the hub is provided with a stopper which restricts the movement in the rotation direction relative to the sleeve; the sleeve is provided with an abutment part which abuts against the stopper when the sleeve rotates in the rotation direction relative to the hub, with a clearance in the rotation direction intervening between the abutment part and the stopper; the hub and the sleeve try to relatively rotate in a direction in which the clearance between the stopper and the abutment part decreases when the back torque is applied from the output shaft; and the restricting apparatus comprises a restricting member which restricts, when a part thereof enters the clearance, the relative movement in the rotation direction of the hub and the sleeve.