The Mechanisms And Protective Measures On Self-excited Vibration On Main Drive System Of The Hot Rolling Cogging Mill

The self-excited vibration on main drive system of the rolling mills not only does bad affects on products,but also even more seriously it causes damage to the equipment. It needs to analyze the main drive system ,in order to improve production quality and production efficiency. At last the reasons of self-excited vibration should come out and then it can put forward corresponding measures to avoid.Simplify main drive system of R1 rolling mill in No.2 Hot Rolling plant of WISCO into multi-degree system.The components with large stiffness such as a main motor,a reducer, herringbone gears and couplings are simplified into concentrated masses. The join components with large deformation such as a rotor shaft of the motor,gear shafts of the reducer,shafts of herringbone gears,spindles and rolls'neck are simplified into torsion springs. So the model with four-degree-fredom is estabished. Solve the natural frequency and main vibration models of the system. The calculated first natural frequecy corresponds with the measured.Further reducing the degree-freedom of torsional vibration model into two, the node position of the two-degree-freedom system should be obtained. Devide the two-degree-freedom system into two independent single-degree-freedom parts. So the single-degree-freedom torsional vibration model of rolls is estabished. The reponse analytic about torsional vibration of rolls is obtained by the multi-scale method using the model.Simulation to the response of torsional vibration is in order to get the influence of changing initial conditons and damping in the expression. Then determine the parameter a0 in initial conditions and the parameter b in damping according to measured datas and get the relationship between speed and friction coefficient. At last the control and prevention measures should be proposed on the basis of simulation results.