Vibration problems in a gear system with backlash

The differential equations describing gear vibration were solved to study the influence of gear backlash and gear load change on gear pair vibration. The fourth order Runge-Kutta with adaptive step size control was used to obtain the time-dependant solutions of the equations. The fast Fourier transformation (FFT) method was then used to obtain the amplitude spectrums of these time responses. The influences of gear backlash and gear load changes on the gear fault vibrational frequency were investigated for a non-harmonic situation. The results show that the gear backlash and its changes greatly influence the gear fault vibrational frequency for constant gear rotational speed and load. Changes of the gear speed and the working load also influence the gear fault vibrational frequency, when the gear backlash reaches a certain value. The results provide a reference for influence on-line monitoring, fault diagnosis and dynamical design of gear unit devices.