Surface Roughness Effect in Hydrodynamic Thrust Bearing with Ultra Low Clearance

Abstract

In the hydrodynamic thrust bearing with ultra-low clearance, even the nanoscale surface roughness is comparable to the bearing clearance, and its effect can be very significant. In this paper, the calculations are made for the performance of this bearing when the surface roughness is on the 1nm scale. It was found that the surface roughness effect in the bearing is strongly dependent on the physical adsorption of the fluid to the bearing surface determined by the interaction strength (or potential) between the fluid molecules and the molecules of the bearing surface; it can considerably enhance the load-carrying capacity of the bearing for the strong interaction between the fluid and the bearing surfaces.