CLUTCH SEAL

The purpose of the present invention is to provide a clutch seal capable of increasing the durability of a membrane section, which is a component of the seal and is obtained from a rubber-like elastic body. Additionally, the purpose is to provide a clutch seal capable of limiting the accumulation of working fluid on the concave surface of the membrane section. Said purposes are achieved by a clutch seal, which: is a ring-shaped seal interposed between a clutch plate and a piston for pressing the clutch plate in a dry clutch; has a middle ring that is fixed to the piston between an outer ring and an inner ring that are fixed to the clutch housing; and has membrane sections between the outer ring and the middle ring and between the inner ring and the middle ring, respectively, the membrane sections being obtained from rubber-like elastic bodies. The clutch seal is characterized in that, in the initial shape of the membrane sections, the middle ring is disposed at an intermediate position of the stroke thereof. The clutch seal is also characterized in that the straight portion of the outer membrane section has an angle of inclination oriented so that the radius decreases from a first fold back portion to a second foldback portion.