A Computer Programme to Determine the Bending and Pitting Stresses of Gears and the Effect of Varying the AGMA Stress Equation Parameters on the Stress Values

Abstract

Gears are one of the most critical components in mechanical power transmission systems. The bending and surface strength of the gear tooth are considered to be the main contributors for the failure of the gears in a gear set. Thus, analysis of these stresses has become imperative in the area of research on gears to reduce errors and omissions in order to prevent the failures, and therefore, optimize the design of gears. The objective of this project is to write a computer programme developed from Microsoft Excel and Matlab softwares, the application of which is aimed at reducing the errors and omissions when calculating the bending and pitting stresses using the AGMA methodology effectively, efficiently and quickly in the design and analysis of spur and helical gears. The procedures employed include  extraction of all the figures from the various graphs, obtaining an equation of the graphs extracted using the curve fitting tool function in Matlab and using the graph equations together with other equations of AGMA. The computer programme has been tested successfully and it has been established that its application is capable of determining the bending and pitting stresses of any spur and helical gears and their corresponding safety factors using the AGMA methodology.

Keywords: Gears; Transmission system; Gear set; Bending and surface strength.