Bending Capacity Enhancement Using an Asymmetric Tooth Profile : 1st Report, Influences of Pressure Angle on Tooth Root Stress and Bending Stiffness

Abstract

This study is to develop a new method to enhance the bending capacity of gear tooth by the use of asymmetric tooth profile. Considering that many power transmission devices operate in one direction, where only one tooth surface (the front of tooth) is practically used. Therefore, it is not necessary to make tooth profile symmetrically, the back profile of tooth, which does not mesh in operation, can be designed to decrease tooth root stress. Different standard pressure angles are used to the front and back tooth profiles. Finite element method was used to calculate the tooth root stress and the bending stiffness of the asymmetrical tooth in several standard pressure angle combinations. Based on the results of calculations, it is clarified that tooth root stress decreases and bending stiffness increases remarkably by the use of a large standard pressure angle in the back profile of tooth, but no clear change in load sharing ratio appears during meshing period.