| 摘要 |
PROBLEM TO BE SOLVED: To prevent lowering of lubricating ability between balls so as to improve sensitivity to unbalancing by forming a groove of specified depth and width along the circumference of a turntable connected to the rotational center of a rotor, and arranging first and second balls of different material alternately in the groove. SOLUTION: A groove 50 of specified width and depth is formed along the circumference of a turntable 30, and first balls 60 and second balls 100 different in material from the first balls 60 are alternately arranged and inserted in the groove 50. The total number of the balls is to be an even number so that the first and last balls are of different material. When power supply is applied in this state, the turntable 30 is rotated in association with the rotation of a rotor 20. At the same time, unbalancing of the turntable 30 is corrected while the balls 60, 100 are rotated. Because of the different material of the balls 60, 100, affinity is lowered, so that frictional heat is not generated, and lubricating ability is increased so as to improve sensitivity to unbalancing. |
