Patent ID: 8657094
Filing Date: 2014-02-25
Classification: F16D

Abstract:
1. A clutch device for a vehicle, comprising: an input shaft rotationally connected to a drive source; an output shaft coaxially arranged with a rotational axis of the input shaft; a case supporting the input shaft and the output shaft by a bearing along the rotational axis so that the input shaft and the output shaft are rotatable; a plurality of first clutch plates movably engaged with one of the input shaft and the output shaft along the rotational axis; a plurality of second clutch plates arranged in an alternating manner with the first clutch plates and being engageable with and separable from the first clutch plates, the second clutch plates being movably engaged with the other one of the input shaft and the output shaft along the rotational axis; a piston slidably fitted to a cylindrical portion along the rotational axis, the cylindrical portion being integrally formed with the output shaft or the input shaft, the piston including a pressing portion pressing the first clutch plates and the second clutch plates; an elastic member arranged between the piston and the cylindrical portion, the elastic member biasing the piston toward the first clutch plates and the second clutch plates and pressing the first clutch plates and the second clutch plates by the pressing portion to engage the first clutch plates and the second clutch plates with one another; a hydraulic chamber defined by the cylindrical portion and a first end surface of the piston and arranged between the cylindrical portion and the first end surface, the hydraulic chamber receiving a hydraulic pressure of oil, the hydraulic pressure allowing the piston to separate from the first clutch plates and the second clutch plates against a biasing force of the elastic member; a canceller chamber defined by the cylindrical portion and the second end surface of the piston and arranged between the cylindrical portion and the second end surface, the canceller chamber connecting to an outer side of the cylindrical portion via a discharge hole formed at a portion of the cylindrical portion, the portion being located at a predetermined radial distance from the rotational axis; and a throttle hole formed in a portion of the piston to connect the hydraulic chamber to the canceller chamber, the portion being located at a radially inward side of the portion of the cylindrical portion.