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The transmission system is subjected to multi-harmonic torque excitation of the engine, random excitation of road, dynamic meshing excitation of gears, and contact excitation of bearings, etc. Wide-band strong excitation acts on a multi degree of freedom nonlinear vibration system, and the transmission route and vibration phenomenon are complicated, vibration and noise issues are prominent. At the same time, the bending torsional coupled vibration, the box and shafts system coupled vibration, and the various modes coupled vibration of the transmission system will also generate strong dynamic loads, and even cause fatigue damage to parts and power interruptions in severe cases. Therefore, it is necessary to further study the vibration characteristics of the multi-stage planetary transmission system, especially the coupling mechanism of the vibration. Most previous researches are based on linear vibration theory or low degree of freedom systems, and less consideration is given to such multi degree of freedom nonlinear transmission systems with strong coupling. However, in multi degree of freedom nonlinear systems, the resonance phenomenon is complex and unavoidable, and under the action of multi-source wide-band strong excitation, multiple resonance phenomena such as main resonance and combined resonance may be induced, which is more complicated than simple systems. Therefore, it is also necessary to deeply study the coupling vibration mechanism of the system and suppress the system resonance. Based on the nonlinear factors such as tooth profile error, dynamic clearance, time-varying meshing stiffness and damping, manufacturing error, installation error, mass eccentricity and geometric eccentricity, a multi degree of freedom nonlinear transverse-torsional-pendulum coupled vibration model of single-stage planetary gear system is established. Under different working conditions, the vibration amplitude and phase of each component were studied, and the vibration form between each component was analyzed. Through frequency domain and time-frequency analysis of vibration response, the vibration coupling relationship between each direction and each component of the system under different working conditions is studied. Through the sensitivity analysis of the system parameters inertia, mass, stiffness of the supporting shaft and mesh stiffness, the key parameters which have great influence on the coupling vibration of the system are identified. The system coupling degree analysis standard of coupling vibration is established, and the influence rule of sensitive parameter change on coupling vibration is summarized. On the basis of coupling vibration analysis, this paper summarizes the coupling vibration analysis method of the system, and optimizes the system to achieve the purpose of vibration suppression.
Mr. Pengfei Yan, Beijing Institute of Technology, CHINA Prof. Dr. Hui Liu, Beijing Institute of Technology, CHINA