| 摘要 |
PURPOSE:To decrease the amplitude of a rotator by increasing the same of a damper through a damper reasonance, when the frequency of said rotator is passing through its natural frequency. CONSTITUTION:In order to decrease the amplitude of a rotator 1 when the velocity of said rotator 1 main body passes through the critical point, the ratio of the natural frequency of said rotator 1 to the same of a damper unit 2 is formulized by a formula 1, where the dampting factor xsiD of said damper 2 alone satisfier xsiD<0.7. A tip portion 4a of a shaft 4 of said rotator 1 is formed larger than the base portion 4b to increase the mass ms of tip portion 42, while maintaining the mass mD of said damper portion 2 to be light, so as to set the total mass m in such that said natural frequency nCD of said damper unit 2 is brought near to the natural frequency nCR of said rotator 1. |
