Abstract:

Root crack and spalling are common gear faults in a gear transmission system.Due to the lack of research on the fault mechanism,these two fault types cannot be accurately identified by the current gear fault diagnosis methods.Based on the energy method,an analytical model is established to analyze and compare the different mechanisms of the influence of the two faults on the time-varying meshing stiffness.A dynamic model of the gear system is established to analyze the vibration response mechanism of the root crack and spalling fault.By comparison,it is found that although the root crack and spalling fault will make the system produce the periodic vibration and impact response,the number and law of impact response produced by the two faults in one meshing cycle are quite different.The research results reveal the differences in vibration response mechanism between root crack and tooth spalling faults,which provides a theoretical basis for the accurate diagnosis of these two kinds of faults.

Key words: gear, root crack, spalling, time-varying meshing stiffness, dynamic model, vibration response mechanism