Development of Foil Journal Bearings for High Load Capacity and High Speed Whirl Stability

Abstract

This paper describes the development of two types of air-lubricated foil journal bearings, designed for separate purposes; stability and load capacity. The first was a three-pad configuration, with each pad forming a wedge whose convergence increases with operating speed (of 120,000 rpm max.). The net result is a highly stable bearing at high operating speed. The second was a single pad journal bearing (43.7 mm diameter × 34.9 mm long) that produced a load capacity of 352 KPa (51 psi) at an operating speed of 68,000 rpm.