Compressibility effects on the static and dynamic characteristics in stepped thrust gas film bearings

摘要

Hydrodynamic gas film bearings are used for supporting high-speed, lightly loaded rotating machinery. Stepped type gas film bearings are often used for such mechinery because of their simple structure, high stability and load carrying capacity. This paper describes the measurements of compressibility effects on the static and dynamic characteristics of stepped thrust gas film bearings. In the experiments, the miniumum film thickness, friction torque on the bearing surface and stiffness and damping coefficients of gas films are measured for a range of rotational speed from 10,000 rpm to 20,000 rpm under a constant stator mass and a fixed step height. The measured data are compared with the theoretical results and teh gas film compressibility effects on the static and dynamic characteristics of the bearings are discussed. The experimetnal results agree well with the predicted results based on the compresible lubrication theory.