Study On Dynamic Behavior Of Main Drive System Of Rolling Mill Under Unsteady Lubrication

The rolling mills are the major equipment in the manufacture of steel.The transmission of moment oscillation in the major gears of the rollers is a pivotal component impacting the stabilization of electrical operation and rolling performance.As a result,it is significant to investigate the twisting motion of the mill primary drive system.Using the major transmission of the roll forming mill as a research object,the dynamic model of the primary gear transmission system of the grinding mill was established considering the unsteady lubrication condition of the roll crack,and the dynamic behavior of the system vibration was studied.Firstly,the effect rule of the variation of the thickness of the import oil layer on the rolling slit table surface contact efficiency under non-stationary lubricated process is researched,and the rolling mill active actuator system is given a detailed model of the active rolling moment.The model of the dynamics of the primary power train of the mill was created on the basis of Newton’s second law,and was then standardized.Secondly,the characteristic expression of the system was given from the Jacobian matrix of the equilibrium point,and the Hopf bifurcation site of the system was counted according to the Routh-Hurwitz code while the coefficient of lubrication of the borders was altered.The divergence of the system type is optimized by the periodic solvency discriminant.In order to control the bifurcation behavior of the system,an improved hybrid control strategy is presented on the motor side of the mill.According to the direct method of Normal form,the influence of controller parameter disturbance and state feedback on the bifurcation position,bifurcation type and amplitude of periodic solution is analyzed.Then,considering the influence of electromagnetic damping,the dynamics model of the main drive system of the rolling mill is given.The Lyapunov-Schmidt reduction method is used to reduce the dimension of the high dimensional rolling mill system.The low dimensional equations are studied according to the singularity theory,and the transition set of the system under the change of related opening parameters is obtained.Finally,the dynamic model of the main drive system of rolling mill with dry friction was established according to the condition of insufficient lubrication between rolls.The stability of periodic solution of the system was studied based on Floquet theory.The set value extension of Filippov convex theory was used to give the conditions of sliding bifurcations.The sliding bifurcation behavior of Poincaré mapping prediction system under boundary lubrication friction coefficient variation was established by numerical prediction method.The numerical simulation method was used to verify the research results and analyze the specific form of sliding bifurcation.