Error motion prediction and structural optimization of a groove-compensated air bearing

Abstract

A new theoretical model of the groove-compensated air bearing is built in this article to predict the error motion and optimize the structure parameters considering the error motion, the stiffness and the flow. To quantitatively evaluate the performance, the averaging coefficient, the dimensionless stiffness coefficient and the dimensionless flow coefficient are used, respectively. The study shows that, whether the error motion happens depends on the symmetrical matching relationship of the grooves, the bush shape and the shaft shape along the circumferential direction. The optimized groove number $n_g$ is 30, the optimized dimensionless land ratio $\overline{b}/\overline{a}$ is between 1.75 and 4, and the optimized groove depth ratio $h_g/h_0$ is between 2.5 and 3.5. Using these optimized parameters, the bearing has the small error motion, the good stiffness, and the low flow. This is of great importance for the error motion prediction and design of the groove-compensated air bearing.