Research on dynamic characteristics of marine engine transmission system

As the main component of marine engine, the transmission system often produces serious vibration and noise, which will significantly affect the performance and service life of the driving mechanism. In order to provide reasonable structural design basis for marine engine transmission system, the dynamic characteristics under different working conditions were studied in this paper. A simplified rectangular structure was applied to express the instantaneous motion state model of the chain link, and the equation was expressed according to Euler kinematics theory. The MNF (modal neutral file) model was derived by making the links and pins flexible parts, and the rigid flexible coupling model of the transmission system was established based on ADAMS. Since invalid constraints were adjusted and replaced, the transmission system model could be simulated and calculated precisely under the conditions of different tension, spindle rotation speed and driving sprocket teeth number. By changing the model parameters through the single variable method, the variation rules of transmission ratio, spindle radial force, transmission ratio deviation and maximum transient stress of chain link were obtained respectively. According to the design and construction of vibration test platform, the simulation result was verified, and the spectrum response results of the chain drive system were obtained. The results show that the rigid flexible coupling model can achieve high simulation accuracy in the chain drive system. Reasonable tension and sprocket teeth number can not only reduce the amplitude, but also reduce the fluctuation of output torque and transmission ratio.