A novel continuously adjustable hydrodynamic bearing

Abstract

A novel form of adjustable fluid film bearing has been devised whereby the hydrodynamic conditions can be changed in a continuously controlled manner during operation. The principle can be applied to conventionally orientated journal bearings, i.e. a shaft rotating within a stationary bearing housing; to inverse orientations, i.e. a rotor on a stationary shaft; and to thrust bearings. A theoretical model and computerised solution technique were developed in which the fluid film profile, temperature, viscosity and pressure fields were simultaneously solved. Experiments were conducted on journal bearing versions for which recently developed measurement techniques demonstrated stable operation at zero eccentricity, and the ability to move the rotational centre whilst in operation. Performance characteristics predicted by the computer model have been demonstrated in practice. The novel bearing has shown significant improvements over conventional designs in tems of stiffness, damping, rotational accuracy, power losses and temperature rise