| 摘要 |
PURPOSE:To suppress the generation of self-excitation vibration owing to a stick slip, to increase the polishing speed of a polishing device, and to improve productivity by a method wherein vibration of a top ring part is detected and feedback of it to a radial bearing through the compensating circuit of a radial control means is carried out. CONSTITUTION:A top ring drive shaft 25 having a lower end to which a top ring 2 to hold an object 1 to be polished between a turn table 11 and the top ring drive shaft is ratably supported through radial magnetic bearings 22 and 24 and a thrust magnetic bearing 23. Feedback of displacement in a radial direction of the drive shaft 25 to the radial magnetic bearings 22 and 24 through compensating circuits 35 and 38 is effected and feedback of displacement in the direction of thrust of the drive shaft 25 to the thrust magnetic bearing 23 through a compensating circuit 42 is effected. Namely, vibration in a radial direction of the drive shaft 25 is detected by a vibration meter, and feedback of the vibration to the radial magnetic bearings 22 and 24 through the compensating circuits 35 and 38 of a radial control means is performed. |
