CONICAL BUMP FOIL BEARINGS FOR COMBINED AXIAL AND RADIAL LOAD APPLICATIONS

Abstract The high speed bearings capable of operating at elevated temperatures have become one of the major challenges in the development of small and micro gas turbines. While foil bearings offer a possible solution, research on foil bearing catering to axial and radial load simultaneously is very scanty. This paper provides details on the investigation schedules related to foil bearings supporting axial and radial load simultaneously. The conical bump foil bearings developed here are tested in an instrumented rig designed and fabricated for the purpose. Two alternatives to provide conical seating in the bump foil bearings are discussed and one configuration is tested. The conical bearing developed during this effort successfully supported a rotor weighing 10 N with an axial load of around 1N at speeds above 50,000 rpm. Nomenclature d Diameter of the shaft (m) D Load capacity coefficient (Pa/m*kRPM) E Young’s modulus of Be-Cu (N/m