Considerations of Flow Across a Bearing Groove

It is known that the majority of heat lost from small bearings is by conduction through the bearing surfaces. A lower proportion is assumed lost by convection from the film. However, it is shown that between 60 and 95 percent of the connected heat re-enters the film on the opposite side of the groove. This proportion of heat carried over is largely unaffected by speed, film thickness, or groove width. Due to the formation of a boundary layer within the groove, a ram pressure is generated at the pad leading edge. Approximate analyses are given for the boundary-layer formation, ram pressure, and heat carried over. Fair agreement is obtained with experimental results.