Spur gear dynamic models including defects: A review

A large number of gear models for simulating the dynamic behavior of gears have appeared in the literature since 1920. In this paper we present a review of the dynamic modeling of spur gears including defects. We give the classification of gear dynamic models by different authors, and we explain various terms that are used in gear dynamic modeling. Gear dynamic models without any defects for single-, two-, and multi-degree-of-freedom systems have been discussed. The effects of various nonlinearities, such as variable mesh stiffness, mesh damping, gear errors, and backlash, on gear dynamic behavior have been discussed. Many researchers are actively developing advanced dynamic models of gear case vibration to ascertain the effect of different types of gear damage. Dynamic models including the effect of friction, wear and spalls on gear dynamic behavior have been considered in detail. The aim of this paper is to emphasize the importance of defect models for a clear understanding of gear vibrations and also to explore areas for introducing other defects in existing gear dynamic models.