Dynamic Force Response of Spherical Hydrostatic Journal Bearings for Cryogenic Applications

Abstract

Hydrostatic journal bearings are ideal elements to replace roller bearings as rotor support elements in cryogenic lurbomachinery. These bearings will be used for primary space-power applications due to their long lifetime, low friction and wear, large load capacity, and direct stiffness and damping force coefficients. The performance characteristics of turbulent flow, orifice compensated, spherical hydrostatic journal bearings are presented. These bearings allow tolerance for shaft misalignment without force degradation and are able to support axial loads, thus providing a design configuration which could be used efficiently on high-performance turbomachinery.

Bulk-flow mass and momentum equations for the motion of a variable properties liquid on the thin film bearing lands are solved numerically. Predictions of load capacity and force coefficients for a six recess, spherical hydrostatic bearing in a liquid oxygen environment are presented. Fluid film axial forces and dynamic coefficients of a magnitude about 20 percent of the radial load capacity are calculated for the case analyzed. Fluid inertia effects, advective and centrifugal, are found to greatly affect the static and dynamic force characteristics of the bearing studied.

Presented as a Society of Tribologists and Lubrication Engineers paper at the STLE/ASME Trlbology Conference in New Orleans, Louisiana, October 24–27, 1993

Notes

Presented as a Society of Tribologists and Lubrication Engineers paper at the STLE/ASME Trlbology Conference in New Orleans, Louisiana, October 24–27, 1993