| 摘要 |
<P>PROBLEM TO BE SOLVED: To increase a rate of balls which are detained in ball detention positions and reduce aggravation of unbalance caused by balls which are not detained in the ball detention positions. <P>SOLUTION: When the rotation speed of a rotator is lower than a first rotation speed, a ball detention portion (105) allows a ball (BB), which is moved therein from a rolling surface (103b), to be detained therein, and allows the detained ball, which is detained in the ball detention portion (105), to come into contact with a released ball, which is not detained in the ball detention portion (105), to thereby prevent separation of the released ball from the rolling surface (103b). A separation preventing portion (106) comes into contact with the released ball, which is not detained in the ball detention portion (105), to thereby prevent separation of the released ball from the rolling surface (103b). When the rotation speed of the rotator is higher than the first rotation speed, the ball detention portion (105) allows the ball (BB), which is detained in the ball detention portion (105), to be separated to the rolling surface (103b) by centrifugal force acting on the ball (BB). <P>COPYRIGHT: (C)2013,JPO&INPIT |
