Abstract
Air-bearing spindle is an essential machine element of the ultraprecision machine tool. In the present paper, a high-speed precision air-bearing spindle is proposed for small diameter of end-mills and grinding wheels. For suppressing the spindle vibration at high rotational speed, an active aerodynamic bearing is incorporated into the aerostatic bearing system. Final goal of this hybrid spindle is as follows: the spindle vibration is less than 0.1um at the maximum rotational speed of 100,000min-1. According to the vibration detected by a sensor, a microcomputer controls the wedge angle of the aerodynamic bearing surface by using a piezoelectric actuator incorporated. Fundamental performance of the hybrid spindle is reported and the method for improving the performance is discussed.
