Bending fatigue strength of case-carburized spur gears with boss

Abstract

Studies on the spur gear, to increase the bending fatigue strength have been published by adopting gear with high pressure angle and positive addendum modification factor. However, studies on the spur gear with wide boss have been hardly published. In this project, the bending fatigue test and the hardness measurement of hardened layer were carried out for various case-carburized spur gears with boss, and S-N curves and case depth were obtained. Effects of case depth and boss width on the bending fatigue strength of case-carburized were examined. From this project, a method to select the suitable boss width for the bending fatigue strength of case-carburized gears with boss was determined.