Research on static performances and gas film flow field characteristics of aerostatic bearings with cross-pressure equalizing groove multi-hole integrated restrictors

Aerostatic bearings are widely used in high-precision manufacturing equipment. Increasing the load capacity and load stiffness of aerostatic bearings is the continuing need for the development of high-precision manufacturing equipment. However, improvements in the load capacity and load stiffness of aerostatic bearings often lead to a reduction in stability. This paper introduces a novel aerostatic bearing with cross-pressure equalizing groove multi-hole integrated restrictor (CMIRB) designed to enhance the load capacity and stiffness, while providing a preliminary stability analysis. The mesh spacing at the pressure equalizing groove boundaries is adaptively adjusted using a linear method, and the CMIRB governing equation is discretized and solved numerically using the finite difference method based on flow balance principles. The characteristics of the gas film flow field were analyzed through three-dimensional steady-state simulations using the pressure-velocity coupling method. The results showed that increasing the width of the pressure equalizing groove from 0.4 mm to 0.5 mm leads to an approximate 13.3% increase in load capacity and a 17.2% increase in stiffness, while also reducing gas flow velocity fluctuations in the pressure equalizing groove. Furthermore, when the depth of the pressure equalizing groove is increased from 0.1 mm to 0.3 mm, the load capacity of the CMIRB increases by approximately 10.3%. The numerical and experimental results prove that the load capacity and stiffness of CMIRB are increased relative to aerostatic bearings with No-groove Multi-hole Integrated Restrictors (NGMIRB).