A model that take the backlash into account and is to analyze the torsional vibration based on 4-order Runge-Kutta method is built in this paper.

• 粗轧机主传动的主轴联轴器由于运行磨损和频繁换辊形成间隙,该间隙在咬钢过程中的启闭会引起系统咬钢冲击,导致主传动较大幅度的扭振。