Paper Title
Parametric Stress Analysis of Spur and Helical Gear using FEA with Aspect Ratio

Abstract
This paper concern with the parametric analysis of a Spur gear and helical gear in order to improve the transmission performance, since the bending and surface strength of the gear tooth are considered to be one of the main contributors for the failure of the gear in a gear set. Thus, determination of stresses has become popular as an area of research on gears to minimize or to reduce the failures and for optimal design of gears. In order to estimate the bending stress, three-dimensional solid gear models are generated by Pro/Engineer that is powerful and modern solid modeling software and imported in the numerical solution is done by ANSYS, which is a finite element analysis package. Lewis and Hert’z Equations are used to calculate gear contact stresses which are derived for contact between two cylinders analytically. Finite Element Method is used to discritized the gear contact problem, the stiffness relationship between the two contact areas is usually established through a spring placed between the two contacting areas. The contact stresses were examined using 2-D FEM models. The bending stresses in the tooth root were examined using a 3-D FEM model. The results of the two dimensional FEM analyses from ANSYS are presented. These stresses were compared with the theoretical values which show the good agreement. From this we can conclude that the proposed gear model of Spur and Helical is accurate. Keywords - Gear, Stress, ANSYS.