Patent ID: 7635118

Claim:
A cylindrical dynamic damper adapted to be installed on a rotating shaft, comprising: a cylindrical mass member disposed radially outwardly spaced away from an outside periphery of the rotating shaft and coaxially therewith; and a pair of rubber elastic support members having a pair of ring-shaped affixing members situated at axial ends of the mass member and adapted to be mounted on an outside peripheral face of the rotating shaft and a pair of elastic support portions of cylindrical shape connecting respectively to the affixing members and to the axial ends of the mass member to thereby elastically support the mass member, wherein the mass member has on inside peripheral corners of both axial ends slanted faces disposed in chamfered profile and varying in shape in a circumferential direction; the elastic support portions connected to the slanted faces have a free length varying in the circumferential direction; the slanted faces are formed such that portions of the slanted faces intruding deepest inwardly in an axial direction are situated in radial symmetry about at two areas that are axis-symmetrical to either side of a bore of the mass body; and wherein the slanted faces of the mass member vary gradually in shape in the circumferential direction, and the free length of the elastic support portions varies gradually in the circumferential direction.