Commentary on effects of tip relief on vibration responses of a geared rotor system

The purpose of the present work is to revise the model of Ma et al. (Proc IMechE, Part C: J Mechanical Engineering Science 2014; 228(7): 1132–1154). In that work, emphasis is given to the effects of tip relief on the lateral-torsional coupling vibration responses of the system, in which the time-varying mesh stiffness (TVMS) is calculated without considering the extension of the meshing period of a teeth pair due to dynamic overloads. Moreover, the dynamic model of the geared rotor system does not take into account no-loaded static transmission error (NLSTE) caused by tooth profile modification. In the present paper, the effect of the extended tooth contact on TVMS is considered and the dynamic model of the geared rotor system is revised by introducing the NLSTE. Based on the revised model, TVMS, loaded static transmission error (LSTE), NLSTE, and vibration responses are determined. Finally, comparisons of TVMS, LSTE, and vibration responses between the original model and the revised model are performed. The results show that there are some differences for the vibration responses between the original model and the revised model, and the vibration amplitude of the latter is smaller than that of the former. Furthermore, the conclusion in the original paper that the tip relief is not effective in reducing the vibration at higher mesh frequency range is not consistent with the results in current work any more.