Abstract:This paper, which takes the compressor rotor system for example, estimates the effect of the coupled gear meshing on dynamic characteristics of a rotor system and conducts a security check on the overall coupled system. Firstly, based on the FEM (Finite Element Method), we establish a general dynamic coupled lateral-torsional-axial-swinging model of helical gear meshing, which considers the effect of mesh stiffness, gear position angle, transverse pressure angle, helical angle and the vibration of the driving shaft to the gearing mesh stiffness matrix. Then, the critical speeds of the system and the safety margin tables are obtained as a result of the analysis of the natural characteristics of the system. Next, unbalance response of the system is analyzed based on MSM (mode superposition method). Unbalanced response curves of every gear mesh point are compared with considering meshing or not. The research results demonstrate that the effect of gear coupling must be considered in a multi-gear meshing system because the vibration between the systems becomes so intense that the critical speeds and vibration peak should be judged by the combination with inherent characteristics and transient response analysis.