Bearing-Cage Frictional Instability—A Mechanical Model

Abstract

Bearing-cage frictional instability is analyzed by means of a simple mechanistic model. This model considers the frictional dynamic aspects of the bearing-cage. The investigation of the motion-stability of this model is based on the concept of Lyapunov functions. It is shown that the bearing-cage operation is frictionally stable whenever the friction force (combined solid and fluid) slope is negative and whenever a condition on the slope and of the order of satisfies an inequality to be established. A simulated test shows the existence of a speed threshold on the onset of frictional stability.