2022 年 88 巻 911 号 p. 21-00336
Jitter Ring is the popular toy which has another name called as “Chatter Ring” or “Gyro Ring”. This toy is composed of a circular ring and the washer inserted into the ring. Just after supplying the washer with an initial angular velocity, the player of this toy has only need to wheel the ring in the vertical state by handling each hand alternately. Then, the washer will continue to rotate with fluctuation by this operation. Further the player will feel the oscillating response through the driving hands. This rotatory motion of the washer is somewhat complicated and the analyses tried up to now concerning this motion don’t almost appear in public. Consequently the author thought that there were the significant meanings in the dynamic analysis for this motion of the washer. Considering the friction between the ring and the washer, he performed the three-dimensional analysis by regarding the washer as the rigid body without a fixed point and adopting Eulerian angles in this research. As a result, the actual behavior with fluctuating rotation of the washer was confirmed by the numerical analysis. Furthermore, he investigated the influence on the motion of the washer by varying each value of parameters in this system.
