The effect of lubricant viscosity change on the performance of hydrostatic thrust bearings.

The lubricant temperature rise in hydrostatic bearings becomes large in high load and high speed operation. Therefore the effects of lubricant viscosity changes on bearing performance are not negligible. In this study, the performance characteristics of capillary compensated multi recess hydrostatic thrust bearings are analysed theoretically and experimentally taking the change in lubricant viscosity into consideration. The relations between the lubricant viscosity change and the load capacity or the bearing clearance variation are shown quantitatively. Close agreement was obtained between theoretical and experimental results. Consequently, it is pointed out that changes in lubricant viscosity should be taken account of when analysing hydrostatic bearings.