Simulation of Wear in a Worm Gear Under Elastohydrodynamic Conditions

The paper is concerned with the prediction of wear of worm gear wheel teeth. The wear model that has been developed is based upon a full elastohydrodynamic lubrication (EHL) analysis of the contact between the teeth at various stages of meshing. Wear over the contacting region on the wheel tooth is calculated from a modified Archard-type law, taking pressure, film thickness and sliding values from the EHL results. The development of wear is obtained by an iterative process in which the shape of the contacting surfaces, as modified by wear, is updated in the EHL solution. This process leads to the prediction of wear contours on the gear teeth from which the increase in backlash (a practical measure of worm gear wear) can be obtained.