The Effect of Rotational Speed on Fluid Compressibility and Gap Pressure of a Partially Porous Aerostatic Thrust Bearing

Abstract

This study investigated the effect of the spindle speed on pressure distribution in the air gap and the load carrying capacity of a porous aerostatic annular thrust bearing. Based on the finite volume method and the pressure-velocity coupling scheme of the SIMPLE algorithm with the standard k-ε turbulent model, a CFD software was used to solve the Navier-Stokes equations to calculate pressure and velocity of the air flow. The results revealed there were positive pressure zones and vacuum pressure zones in the air gap between the thrust disk and the bearing. Under the same spindle speed, the pressure difference between the positive peak and the negative peak in the case of incompressible air was greater than that in the case of compressible air. The averaged pressure on the surface of the thrust disk with compressible air flow was higher than that with incompressible air flow. So was the load carrying capacity of the bearing, which increased when the spindle rotated faster.