Modeling and vibration characteristics analysis of flexible spiral bevel gear system

Abstract

This paper proposes a novel modeling approach for the spiral bevel gear system that incorporates the flexibility of both gears and thin-walled hollow shafts. Shell elements are employed to model the gear and shaft structures. To more accurately represent the interaction between components, a flexible connection is introduced to replace the conventional rigid beam coupling between bearing and shell elements. The gear meshing process is simulated using distributed springs rather than a single equivalent spring, and the component mode synthesis (CMS) method is applied to enhance computational efficiency. The proposed model is validated by comparing its modal and dynamic responses with those obtained from a finite element model (FEM). Using this model, the effects of interfacial coupling methods, meshing methods, gear flexibility, and rotational effects on the system's dynamic behavior are systematically analyzed. The results demonstrate that, for large diameter-to-thickness ratios, the traditional rigid coupling method introduces significant deviations in modal analysis and resonance prediction. Conventional meshing simulation methods exhibit limitations in accurately predicting critical rotational speeds. The conventional model neglects the flexibility of the gear and the radial deformation of the hollow shaft, resulting in substantial errors in resonance prediction compared to the proposed model. These findings highlight the necessity of incorporating gear and shaft flexibility. Moreover, the gyroscopic effect (GE) is identified as the dominant contributor among rotational influences and warrants particular attention.