Lubrication mechanism and characteristics of aerostatic bearing with close-spaced micro holes

Abstract

Insufficient load capacity and stiffness of aerostatic bearings with traditional inherent orifices is limiting their applications. Recently, the aerostatic bearing with close-spaced micro holes (ABMH) shows the potential of performance improvement. However, its lubrication mechanism is still not clear and the static characteristics have not been comprehensively investigated. This paper applies numerical method and extends the pneumatic resistance theory from single orifice bearing to ABMH to reveal its lubrication mechanism. The results indicate that ABMH reduces the gas flow towards the high-pressure region of bearing center and impedes the pressure decrement in this area, thus resulting in the higher load capacity and stiffness. Additionally, bearing load capacity has positive relationships with total mass flow rate and exhibits similar varying trends.