scope:

This paper reports on surface fatigue testing. The goal was to develop models for predicting wear. As part of this goal, the study reports on developing an understanding of the stresses and wear predictors using FZG tests. Since the focus was on micropitting, the first tests used the method described in FVA Information Sheet No. 54/I-IV. Later, the procedure was modified to account for higher contact stress levels that are predicted for the heavily crowned and tip relieved AGMA test gears that were manufactured as a part of the AGMA tribology test program. This paper provides extensive analysis that includes detailed topography measurements of the tooth profiles, predictions of contact stresses and contact patterns. It discusses factors that affect contact stresses, flash temperatures, and test film thickness.