Friction in journal bearings

Abstract

Friction in fluid Journal. Bearings is usually investigated by measuring the torque which appears on a bearing whilst a shaft is rotated inside it. The bearing is supported hydrostatically which would allow it to rotate freely if otherwise un restricted. Motion of the bearing is restricted by tension gauges which indicate the frictional force which they are resisting. The work described in this thesis is concerned with a new method of measuring frictional torque In journal bearings. The method consists of driving a shaft up to a given speed inside a fixed bearing and then permitting it to decelerate freely. The decelerations are timed electronically and almost instantaneous deceleration rates are obtained. From these deceleration rates and known polar moment of Inertia, the frictional torque in the bearing can be found for given speeds. The method has been found to be very reliable and also has wider application with other rotating systems.