Numerical Analysis of variation in mesh stiffness for Spur Gear Pair with Method of Phasing

Abstract

Gearing assembly remains one of the major vibration sources in power transmission systems especially used in automotive, aerospace, marine and industrial applications. This study presents a novel means of reducing gear vibrations using a simple 1:1 ratio spur gear pair using a method of phasing. Variation in the gear mesh stiffness over a mesh cycle which depends on the number of pairs of teeth in contact is one of the principal causes of vibrations and instabilities and has a strong influence on the overall dynamics of the geared system. This method is based on reducing the variation in gear mesh stiffness by adding another pair of gears with phasing. Because of added phasing gear, the numbers of pairs of teeth in contacts are increased which reduces the variation in mesh stiffness. A simple spur gear model with rectangular-wave-type mesh stiffness are assumed and mesh stiffness variation is obtained numerically using MATLAB 7.5 software and is comparable in both cases i.e. normal and phasing gears. The numerical result of analysis shows the reduction in mesh stiffness variation and the possibility of reduction in vibration in simple spur gear pair using the proposed method.