Effects of staggering and pitch error on the dynamic response of a double-helical gear set

Theoretical analysis is conducted to investigate the nonlinear vibration response in a double-helical gear set under the influence of staggering, single pitch error and cumulative pitch error. A dynamic model of the double-helical gear set is established considering the axial deflection of shaft and gyroscopic effect, and the natural frequencies, mode shapes and critical speeds for the gear set with axial degree and gyroscopic effect are calculated. Moreover, several cases are numerically simulated after consideration of time varying mesh stiffness and gear backlash, and then some general results are deduced about the influences of staggering, single pitch error and cumulative pitch error on vibration intensity and gear teeth impact. Although the pitch error is modeled as a lower frequency excitation, high natural frequencies and modes are excited, especially when the double-helical gear pair operates under high speed condition. Comparisons are listed which are useful for understanding the high speed performance of a high speed gear set.