Investigation of tribological behaviors of annular rings with spiral groove

A series of experiments is conducted to study the tribological behavior of spiral groove thrust bearings. The experimental system consists of a nominally flat upper ring mating with a stationary spiral groove lower ring in fully flooded lubrication environment. Spiral groove thrust bearings with different spiral angles subjected to different loads and speeds are tested. Stribeck-like curves are obtained and their characteristics are discussed. Transition points from mixed to hydrodynamic lubrication are experimentally established. In addition, a theoretical model is developed to gain further insight into the frictional characteristics of spiral grooves in both the hydrodynamic regime and the mixed lubrication regime.