ANALYTICAL, NUMERICAL, AND EXPERIMENTAL INVESTIGATION OF THE FLOW STRUCTURE IN A FLOODED BALL-BEARING

Using an order of magnitude estimate of the lending terms in the equat ions of motion, the three-dimensional flow in a flooded ball bearing i s reduced to the investigation of two-dimensional pow problems in a se ries of bearing cross sections. Combining, through appropriate compati bility conditions, the individual analytical solutions for the spaces confined between the cage and the inner wall of the rings, the balls a nd the rings and the balls and the cage's holes, a very simple analyti cal model is derived. It allows the computation, in the laminar regime , of the flow rate, the pressure drop, and the velocity profile in dif ferent cross sections of the confined spaces. The results of the analy tical model are confirmed by those obtained using a CFD code and exten ded to the turbulent regime. The analytical and numerical results are compared to those obtained from pow visualizations and velocity measur ements conducted in a specially designed large scale model of a ball b earing. The agreement is very satisfactory.