Study on Welded Structure Gears : 1st Report, Effect of Rim Thickness on Root Stresses and Bending Fatigue Strength

Abstract

Weldability and bending fatigue strength of rim materials for welded structure gears were examined and the recommendable materials were indicated. Effects of rim and web thickness on root fillet stresses were investigated experimentally. The root fillet stress shows the highest value at the middle of the face width and it increases as the rim and web thickness decrease. Welded gears with different rim thickness were tested using a pulsator of hydraulic type. It was found that the bending fatigue strength of gear teeth decreases with a decreasing rim thickness and that the rim part may break when rim thickness is smaller than one module. The minimum allowable rim thickness for welded gears is also suggested, from the viewpoint of bending fatigue strength, on the basis of experimental results.