| 摘要 |
PURPOSE:To bring a damping capacity into full play as well as to secure a suitable resonance ratio. CONSTITUTION:A mass body 22 is joined to the circular plate surface of a pulley 1, and this mass body is molded into a ring form around a boss part 11. In this mass body, each recess is formed on the pulley plate surface at two spots of a radial symmetrical position, and an elastic rubber body 211 is joined together in space between vertical surfaces 22a-22d of a recess inner surface and circumferential sides 14a-14d of a projection 14 erecting from the pulley plate surface. When a torsional vibration is inputted, the elastic rubber body is expansibly deformed, generating a large spring force there, therefore even if the moment of inertia in the mass body is made larger, torsional resonance frequency becomes heightened to the full. When the input direction of bending vibration is accorded with a direction connecting the projection 14, the generated spring force becomes smaller as the elastic rubber body is subjected to shearing deformation, thus bending resonance frequency is lowered. Accordingly, a resonance ratio becomes lessened suitably, and a sufficient samping capacity is brought into full play owing to the large moment of inertia. |
