Study on vibration problems of a gear system with backlash

In order to study the influence of gear backlash on the vibration of a gear unit, the differential equations of gear vibration are first set up, and then the fourth order Runge-Kutta method with adaptive step size control is employed to obtain the numerical solutions of the time domain responses of gears. Using the FFT method, the amplitude spectrums of gears are also obtained. The influences of the appearance of gear backlash and the change of gear's load on vibration frequency of gear fault are investigated in the non-harmonic situation. The results show that the appearance and the change of gear backlash have a great influence on vibration frequency of gear fault while the gear's working rotating speed and the change of working load also influence the vibration frequency of gear fault when the gear backlash reaches the certain value. The results above are important for the on-line monitoring, fault diagnosis and dynamical design of a gear unit device.