On the prediction of steady-state wear rate in spur gears

Determination of wear rate in spur gears requires treatment of the mixed elastohydrodynamic lubrication problem along the gear's line of action (LoA). For this purpose, a procedure is developed to predict the film thickness, traction coefficient and the wear rate with provision for the interactions between the surface asperities of the gear's teeth at each point on LoA. The results reveal that the surface finish has a more pronounced influence on the wear rate compared to the traction coefficient. The wear results are also compared to those obtained by an engineering approach that utilizes an estimate of the contact flash temperature with reasonable accuracy. Also investigated is the effect of starvation on the wear rate for applications where the inlet is not fully flooded. The results show that wear rate can be enormously large depending on the degree of starvation.