摘要 |
In order to achieve downsizing, and to prevent a cleaning fluid from staying inside, a dynamic damper for a hollow rotating shaft is provided with a mass body floatingly inserted to an inner periphery of the hollow rotating shaft, of which a vibration is to be reduced, and an elastic body structured such that an inner diameter portion is fitly attached to an outer periphery of the mass body and an outer diameter portion is brought into pressure contact with an inner peripheral surface of the hollow rotating shaft, and made of a rubber-like elastic material, wherein grooves having both ends open to spaces at both sides in an axial direction of the elastic body are formed in one of fitted surfaces to each other of the mass body and the elastic body. |