Prediction of Tooth Root Bending Strength

摘要

The teeth of gears can fail under fatigue from pulsating cyclic bending. Thus, it is always necessary to prove the tooth root bending strength before a gear is exposed to service loads. Assuming as a working hypothesis that the locally endurable fatigue strength amplitude from notched laboratory specimens should be equal to the locally endurable stress amplitude of a component, which has the same highly loaded volume, fatigue tests were made with bar shaped laboratory specimens and small spur gears from two sintered steels. Based on the specimen results an attempt was made to predict the tooth root bending strengths at different densities and stress ratios. The agreement between prediction and measured tooth root strength is satisfactory.