Performance analysis and optimization of aerostatic bearings with arrayed multi-orifice restrictors

Abstract Aerostatic bearings are extensively utilized in applications such as semiconductor processing and ultraprecision machining. However, turbulence in the bearing recess induces micro-vibration, which significantly affects stability. This study proposes an innovative arrayed multi-orifice restrictor (AMR) with square or circular distribution to limit the generation of turbulence and diminish bearing micro-vibration. The steady air flow field properties and static performance of bearings with square and circular AMRs are compared under various AMR geometric parameters through computational fluid dynamics. Through three-dimensional large eddy simulation, the transient flow properties of the flow field and pressure fluctuations of the bearings with AMRs are analyzed. This analysis clarifies the influence of the array number, spacing, and distribution types on the suppression of turbulent vortex occurrence and vibration amplitude. Results demonstrate that the optimized design of AMR significantly suppresses the generation of turbulent vortices, which makes the airflow entering the recess more uniform and orderly. Consequently, the vibration amplitude of bearings can be reduced effectively without sacrificing the load-carrying capacity and stiffness. Bearings with circular AMR have better stability and weaker vibration amplitude than those with square AMR.