Active closed-loop gap control for aerostatic bearing

Abstract

Advantages of aerostatic bearing are clean, no pollution and very low friction force. Therefore, it can easily be found in many high-precision machine tools and measurement equipments. However, owing to the compressibility of air, the stiffness of aerostatic bearing is relatively low compared to traditional ball bearing or hydrostatic bearing. In order to improve this fault, an active closed-loop gap control for aerostatic bearing with higher stiffness is proposed. First of all, an aerostatic bearing is designed and manufactured according to a previous report. Next, an experimental test rig based on LabVIEW software for the proposed active closed-loop gap control is constructed. Finally, it is proved that the gap between the aerostatic bearing and workpiece can be held at a stable and constant value even when the bearing is subjected to variable external disturbances.