Analysis of Compliant Foil Bearings with Spatially Variable Stiffness

Heshmat, H. “Analysis of Compliant Foil Bearings with Spatially Variable Stiffness,” Paper No. AIAA-91-2102, AIAA/SAE/ASME/ASEE 27th Joint Propulsion Conference, June 24-26, 1991, Sacramento, CA.

The present work considers the performance of a compliant foil thrust bearing with a spatially variable stiffness.  After outlining several structural modes of varying stiffness, the paper proceeds to an investigation of the deflections, stiffnesses, and hydrodynamic characteristics of a bump foil strip.  The analysis takes into account the mutual interaction between the adjacent bumps as well as Coulomb damping induced by the relative motion between the bump foil and its adjacent surfaces.  A specific calculation is conducted for an optimized thrust bearing with a line or variable stiffness in the circumferential direction.  The benefits of such a design are shown to lie in increased load capacity and reduced power dissipation.