Simplified traction prediction for highly loaded rolling/sliding EHL contacts

A simplified traction prediction approach has been developed for highly loaded EHL contacts accounting for non-Newtonian and thermal effects. For validation, a reference fluid squalane was used for traction measurements at high Hertzian contact pressures (1.25 to 2.66GPa) at three velocities of 5, 10 and 15m/s. Good agreement was seen for traction curves in a semi-log scale at a low speed of 5m/s, whereas for higher speeds at 10m/s and 15m/s, the measured traction curves are lower than the predicted ones. This reduced friction in the experimental results is caused by the increase in mass temperature of the discs. Two possible mechanisms for this reduced friction due to solid body temperature effects are discussed.