The influence of centrifugal forces on friction and wear in rotational sliding

To investigate the influence of centrifugal forces on the oil film stability and the lubrication regime, mirror polished steel surfaces (AISI 304) were tested using a ball-on-disc tribometer in rotational sliding mode with a steel counter body (AISI 52100). Different sliding radii (1.5 and 6 mm) were used to vary the angular velocity. The tests were conducted under fully-flooded conditions using Poly-alpha-olefin oils. The measured coefficients of friction were complemented by the measurement of solid-solid contact ratios and the analysis of the respective wear tracks. It could be shown that the centrifugal forces have a great influence on the oil film lifetime. Thereby, the oil film lifetime is longer for larger sliding radii and higher viscosities.