Nonlinear Analysis of Vibro Impacts for Unloaded Gear Pairs With Various Excitations and System Parameters

Abstract

Torsional systems with clearancetype nonlinearities have inherent vibratory problems such as gear rattle. Such vibroimpacts generally occur on the unloaded gear pairs of a vehicle correlated with the firing excitation of an engine. This study investigates the gear rattle phenomena on unloaded gear pairs with different excitation conditions and various system parameters. First, a linear timeinvariant system model with six degrees of freedom is constructed and then a numerical analysis is applied to the gear rattle motion. Smoothening factors for clutch stiffness and hysteresis are employed for the stability of numerical simulations. Second, the dynamic characteristics of vibroimpacts are studied by examining the fast Fourier transform (FFT) components of the gear mesh force in a high frequency range. The effects of various system parameters on the vibroimpacts are examined using a nonlinear system model. Finally, the vibroimpacts, in terms of “singlesidedâ€‌ and “doublesidedâ€‌ impacts, are identified in phase planes.