Influence of Varying the Normal Load Position on Maximum Bending Strength of asymmetrical Helical Gear Tooth

Abstract

The primary common causes of gear tooth failures are the bending stress on loaded gear tooth. wherein the gear tooth fillet is an area of maximum bending stress that occurs on the loaded and unloaded side. Theoretically, bending stress has been evaluated in standard helical involute gear which is designed for transformation of rotation between parallel axis based on classical method. Later, this equation has been modified in order to evaluate the effect asymmetric teeth on bending stress. This paper presents a numerical analysis by using finite element technique, accomplished basically by using SOLIDWORKS software 2016 package to investigate the influence of varying the normal load position on maximum bending stresses of asymmetrical helical gears tooth drive and comparing with those of the most common standard gear tooth. The aim of the numerical method is to interpolate an approximate solution to boundary value problem. The results of this work showed for an asymmetrical helical gear with teeth profiles having loaded side pressure angle of (14.5°) and unloaded side pressure angle of (35°) is better by  about 14.278 % when the load acts at the tip of the tooth and about 29.582% when the load acts at the root of the tooth than a conventional helical gear from point of view of tooth bending strength. Also, there is a reduction 14.248% and 29.587% in the maximum tensile root fillet stresses when the total load position varies along the helical gear tooth profile from tip to root.