Numerical and Experimental Analysis of Spur Gears in Mesh

Abstract

The investigation of numerical methods for modelling the mechanism properties of involute spur gears in mesh, over the mesh cycle, forms the major part of this thesis. Gearing is perhaps one of the most critical components in power transmission systems and the transmission error of gears in mesh is considered to be one of the main causes of gear noise and vibration. Numerous papers have been published on gear transmission error measurement and many investigations have been devoted to gear vibration analysis. There still, however, remains to be developed a general Finite Element Model capable of predicting the effect of variations in rigid body gear tooth position, in which the critical stage is the prediction of gear behaviour with profile modifications (including tip-relief).In this thesis, FEA results have been obtained by using various techniques including: (a) adaptive re-mesh with contacts using quad (2D) and brick (3D) elements and (b) the element birth and death option. Tooth profile modifications can affect the behaviour of the gear meshing including the T.E., ratio of local deformation and load-sharing ratio results, etc, providing an alternative method for gear design. In the high order end, the elastic strains of the gear-shaft system have also been investigated. The results in this thesis have shown the potential for using strain-vibration relationships to monitor or control the transmission system. The investigations have also included some analysis with non-metallic gears, an application area that is rapidly growing. The results achieved here are at a fundamental stage, and further research would necessitate applying a coupled field analysis (structural and thermal).