A Design Methodology for Obtaining Infinite Stiffness in an Aerostatic Thrust Bearing

The desire to maintain high positional accuracy has led to many unique bearing designs which achieve high, and even infinite, stiffness. This paper presents a design procedure for an aerostatic thrust bearing and demonstrates that infinite stiffness may be attained by proper selection of the bearing’s geometric parameters. The bearing is comprised of two main components; the bearing housing and a flexible membrane that deflects due to changes in load. The current analysis employs plate equations to approximate the behavior of the membrane. Optimization techniques are utilized in the design algorithm and the results are presented in the form of a design chart or nomograph. Additionally, so that the results may be extended to other bearing sizes and gas properties, scaling laws are developed based on a dimensional analysis of the associated variables.