Measurement of Cage and Pocket Friction in a Ball Bearing for Use in a Simulation Program

Few measurements have ever been made of the drag forces arising in a ball bearing due to viscous friction of the balls rotating in the cage pockets and the cage rotating inside the raceway. This paper reports measurements of both these sources of friction on simulations of just one bearing, but the data are compared with general analytical expressions for predicting the friction, and agreement is good. Finally, the data for the ball/pocket friction are compared against a theoretical model based on simple viscous shear and are shown to be in excellent agreement.