PURPOSE: To secure the high vibrationproofness for the variable torque input and improve the durability of an elastic body for the application of an excessive torque by forming the shape of the inner wall surface of an outside outer cylinder nearly to a cylindrical form and forming the shape of the outer wall surface of an inside outer cylinder nearly to a cylindrical form and interposing the elastic body on the whole surfaces between the inner and outer wall surfaces.

CONSTITUTION: The torque inputted into a shaft 6a is transmitted a shaft 6b through the course of an outside outer cylinder 2 → elastic body 4 → inside outer cylinder 1 → triport member 5. When the variable torque is inputted into the shaft 6a, a reciprocating relative shift is generated between the inside outer cylinder 1 and the outside outer cylinder 2 according to the variable torque, and since each shape of the inner wall surface 2a of the outside outer cylinder 2 and the outer wall surface 1a of the inside outer cylinder 1 is nearly cylindrical, and the elastic body 4 is interposed on the whole surface between the inner and outer wall surfaces 1a and 2a, only a shearing force is applied uniformly over the whole periphery of the elastic body 4. Accordingly, the inputted variable torque is attenuated by the elastic body 4 which is shearing- deformed.