Vibration damper for power unit.

摘要

A vibration damper for damping roll vibration of a power unit (2) mounted on a vehicle body (1). The vibration damper (A) is composed of a disc plate (12) fixedly connected to the power unit (2) in a manner that the axis of the disc plate (12) is generally parallel with a roll axis of the power unit (2). The disc plate (12) is sealingly disposed in a chamber (11a) formed in a generally circular casing (11) which is coaxial with the disc plate (12). A viscous fluid is filled in a space defined between the disc plate (12) and inner surface of the casing (11). The casing (11) is formed of a plastic which is higher in linear expansion coefficient than a metal forming the disc plate, thereby allowing the space filled with the viscous fluid to expand along with thermal expansion of the viscous fluid.