A Study on the Evaluation of Bending Fatigue Strength for 20CrMoH Gear

Abstract

A test apparatus for determining the bending fatigue characteristics of gear teeth was used in this paper. Experiments were performed in the test apparatus using a standard spur gear test specimens made from 20CrMoH gear steel. Test apparatus, specimen fixture, spur gear test specimens, the properties of gear material were also introduced as well as the method to determine the stress levels. The test data was analyzed and processed by statistical methods, and the equation parameters of gear bending fatigue and the bending fatigue limit were obtained. The analysis results showed that the three-parameter Weibull distribution was to fit the given stress for the bending fatigue life of 20CrMoH carburized gear with better precision and adaptability. And the P-S-N (Probability-Stress-Life) curves for the bending fatigue strength had been obtained by the reliability theory. It would provide a reliable basis for the reliability design for 20CrMoH carburized gear fatigue life.