Effect of the gear finishing process on bending fatigue crack initiation and propagation in spur gears

摘要

The depth and stress levels of residual stress profiles are a major concern in carburized components such as transmission gears. Residual stress profiles are, among other factors, a function of the gear steel composition, the carburizing process and the gear finishing process. One of the goals of the finishing process in gears is to obtain a certain level of toughness in the gear teeth to reduce and/or eliminate bending and contact fatigue failures. This article presents a comparison of the characteristics of bending fatigue crack initiation in cubic boron nitride (CBN)-ground only and CBN-ground and shot-peened gears during single-tooth bench testing, and also a comparison of the characteristics of bending fatigue crack initiation in shot-cleaned only and CBN-ground only gears during single-tooth bench testing. The gear steel used in this study was SAE 8620/22.