Motion of a Small High-Speed Rotor in 3 Types of Foil Bearings

Abstract

Experiments are conducted with 3 types of oilless (air lubricated) foil bearings and a small rotor, at speeds up to and in excess of 3,500 rps (210,000 rpm). The modular construction of the experimental apparatus provides for interchangeability of foil retainers in the supporting brackets, for their alignment, and for the positioning of bearings at various stations along the rotor axis. The symmetrical rotor, 12.7 cm (5.0 in.) long and weighing 2.97 N (0.667 lb) has both cylindrical and conical journals. The main purpose of the investigation is a preliminary examination of whirl-suppressing (stabilizing) characteristics of these flexible bearings, with the objective of application to small high-speed turbomachines.