The effects of different slide-to-roll ratios have been experimentally investigated under steady state and transient conditions using a steel ball in contact with the plane surface of a glass disc. Under transient conditions the entraining velocity has been varied with a sinusoidal law at two different frequencies. Measurements of the friction force as well as of the film thickness and shape by optical interferometry have been made. Different trends of the friction coefficient at the same working conditions for positive and negative slide-to-roll ratios have been found to be related to different values and shapes of the film thickness. The combination of some different thermal effects can furnish a possible explanation for the obtained results.
The influence of the slide to roll ratio on the friction coefficient and film thickness of EHD point contacts under steady state and transient conditions
CIULLI, ENRICO;
2009-01-01
Abstract
The effects of different slide-to-roll ratios have been experimentally investigated under steady state and transient conditions using a steel ball in contact with the plane surface of a glass disc. Under transient conditions the entraining velocity has been varied with a sinusoidal law at two different frequencies. Measurements of the friction force as well as of the film thickness and shape by optical interferometry have been made. Different trends of the friction coefficient at the same working conditions for positive and negative slide-to-roll ratios have been found to be related to different values and shapes of the film thickness. The combination of some different thermal effects can furnish a possible explanation for the obtained results.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
