Role of Foil Bearings in Advancement and Development of High-Speed Turbomachinery

Heshmat, H. “Role of Foil Bearings in Advancement and Development of High-Speed Turbomachinery,” Second ASME Pumping Machinery Symposium, Fluid Engineering Conference, June 20-24, 1993, (1993) Pumping Machinery, Edited by P. Cooper, FED – Volume 154.

Compliant, air-lubricated foil bearings have been developed for the cabin cooling turbocompressors of new commercial aircraft, the FALCON-2000, with an extension to the MIRAGE 2000 military aircraft.  During their development, the bearings for these air cycle machines were subjected to demanding requirements to endure safety and durability while simultaneously attaining improved system performance.  For this application, the bearings are required to operate at high speed (90,000 rpm), the rotor is lightweight, and the dynamic forces – external shock and vibration – exceed steady-state loads by an order of magnitude.  This paper discusses the compliant foil bearing design analysis, bearing performance, and system rotordynamics, including critical speeds and rotor imbalance response.  Also presented are full rotor bearing development and operational procedures consisting of test results of steady-state and random vibrations obtained from both a rotor bearing simulator and an actual system.