Traveling wave resonance analysis of flexible spur gear system with angular misalignment

The aero-engine spur gear system is often designed as thin rim structure due to lightweight consideration, which leads to traveling wave resonance phenomenon when spur gear system has angular misalignment during operation. This paper mainly analyzes traveling wave resonance phenomenon of aero-engine angular misalignment thin rim spur gear system. Time-varying mesh stiffness (TVMS) of spur gear system is calculated by loaded tooth contact analysis (LTCA) method, angular misalignment is introduced into spur gear system, and axial component of TVMS is obtained by the projection method. Flexible gear foundations are simulated by 8-node shell element and rotational shafts are simulated by Timoshenko beam element, combined with axial stiffness, the dynamic model of flexible spur gear system is established. Simulation results are compared with the references and finite element (FE) model, which proves the accuracy of the proposed method. The analysis results of angular misalignment spur gear system traveling wave resonance phenomenon show that during the operation of spur gear system, angular misalignment produces axial excitation, which excite nodal diameter vibration of gear foundations, and traveling wave resonance phenomenon appears at nodal diameter vibration resonance speed. The effects of misalignment angle, web thickness and gear torque on spur gear system traveling wave resonance amplitude and resonance speed are discussed. The research of aero-engine angular misalignment spur gear system provides theoretical basis for structural design and fault diagnosis of aero-engine gear systems.