Analysis the influence of the structure-fit-working parameters of the laminated coupling on the dynamic characteristics of the shaft system

Abstract The torsional vibration phenomenon of the crankshaft system can trigger faults such as burnt tile and flywheel deformation. The coupling is an important structure for regulating the torsional vibration of a shaft system. Most of the literature has only studied the effects of coupling misalignment, damping nonlinearity and excitation nonlinearity on the torsional response of the system, while ignoring the vibration bifurcation caused by the coupling structure and fit parameters. To address the above limitations, this paper establishes a torsional vibration mechanics model of crankshaft-coupling-rotor based on Lagrange dynamics. Mathematical models of coupling inclination angle, excess and torsional stiffness are constructed using the finite element method. The effects of coupling inclination angle, excess and angular velocity on the vibration bifurcation of the shaft system are discussed separately by the 4th order Runge-Kutta methods. The results show that with the increase of the inclination angle, the vibration state of the shaft system switches between chaos and divergence, which is not conducive to the torsional vibration control of the shaft system. At the same time, the increase in the excess will lead to an increase in the angular velocity of vibration, which in turn will lead to increased wear of the shaft system and bearings. In addition, after considering the nonlinear characteristics of the coupling stiffness, the vibration amplitude of the shaft system rises with the increase of the angular velocity, and the vibration state transforms from periodic to divergent. Finally, a coupling field vibration test study was carried out to verify the accuracy of the numerical model.The research results of this paper have theoretical reference value for determining the coupling structure-fit parameters and the angular velocity of the shaft system.