Study Of Dynamic Characteristics Of Hollow Rotor Systems Of A Large-scale Eliptical Oscillating Screen

Three-axis elliptical oscillating screen is efficient.It can handle a large number of materials at a time and some materials which are hard to deal with.Rotor system decides the performance of vibrating screen,and the existence of the crack can lead to the rotor system's dynamic characteristics changing.The rotor will not only vibrate along the trajectory of screen in the inertial system,also vibrate in a non-inertial system because of eccentric mass.In this paper,the dynamic characteristics of the oscillating screen,the effect of crack on the dynamic characteristics of the rotor system and the performance of vibration suppression of nonlinear energy sink in rotor systems are investigated.The main research work is listed below:(1)How the oscillating screen works is analyzed.Its operating parameters are calculated.The finite element model and modal analysis of the oscillating screen are done.Considering the force situation,its dynamics model is proposed and an analytic solution is obtained.(2)The models of the transverse and slant crack on hollow shaft are proposed.And the effects of the depth and angle of cracks on the additional flexibility are analyzed.Considering the nonlinear whirling motion,the stiffness modal of the cracked shaft is proposed and applied in the governing equation of the rotor system.The influence of the crack depth,diameter ratio,vibration amplitude of the screen and rotate speed on the system's dynamic characteristics are analyzed.(3)The dynamics model of the rotor system coupling a dynamic absorber which applies nonlinear energy sink is studied to mitigate the vibration amplitude of the rotor system and its stability criterion is deduced.The effects of parameters on the system coupling single degree of freedom of NES and two degree of freedom of NES are studied.