Influences of Lubricant Viscosity Ratio on Static Characteristics of Hydrostatic Thrust Bearing

Chung Yuan Christian University, Department of Mechanical Engineering, 32023 Chung Li, Taiwan, R.O.C

^a Corresponding author: yk@cycu.edu.tw

Abstract

This paper uses numerical simulation to study the influences of viscosity ratio on the static characteristics of hydrostatic thrust bearing compensated by various restrictors. The design parameters of open type hydrostatic bearing include: effective area, supply pressure, restriction constants of restrictor and bearing pad, and specific value of average viscosity of the lubricant passing through restrictor and bearing pad film. The optimal design requirements of restrictors and hydrostatic bearing and the corresponding range of design parameters for excellent bearing characteristics can be obtained from the relationships between these design parameters together with their composed parameters and ratios, and the static load capacity and film stiffness and worktable displacement of hydrostatic bearing. Fixing the other design parameters and changing viscosity ratio, the simulation results depict that the lubricant viscosity during restrictor being greater than that in bearing pad film will make the load capacity decrease, but will improve the film static stiffness.