Fracture Analysis And Structure Improvement Of Roller Table Motor Shaft Of Large Rolling Mill Stand

The stand roll is a work roll table that is driven by several individual rollers that are closest to the mill roll.The utility model can reliably feed the rolled piece into the roller of the rolling mill,and plays an important role in the transportation of the rolled piece.The Motor shaft of the frame roller table broke twice on the production line of a steel rolling plant.The fracture of the motor shaft makes the stand roller become the idler roller,which causes the friction of the rolling steel on the roller table to increase,affects the surface precision of the rolled steel,the steel produced does not meet the expected standard,and brings serious influence to the rolling steel production,so it is very important to analyze the fracture reason and improve the structure.Based on the theory of multi-body dynamics,the dynamic simulation of the roller table system is carried out,and the simulation results are analyzed and extracted and the loading conditions are introduced into the finite element software,the strength and life analysis of the motor shaft are realized.The specific contents of the study include:(1)Using the 3D modeling software Solidworks to build the 3D model of the roller table system.The main impact of the roller table system comes from the impact of steel on the stand roller table during tapping,the impact force of the steel on the roller table and the influence of the maximum torque which may be produced by the overload of the motor on the roller table motor shaft are analyzed through relevant calculation and simulation.(2)Aiming at the gap between the Roller Motor shaft and the Flange because of insufficient pre-tightening force,Adams simulation is used to analyze the force acting on the motor shaft without axial gap,2.5 mm axial gap and 5 mm axial gap.Because of the limitation of the field area and other factors,the influence of the inclination angle of universal coupling on the shaft of the roller table motor is also different.(3)With the aid of Adams Simulation,the Torque of impact and motor overload on the X,Y and Z axes of the roller table motor is extracted,and the load conditions such as the pre-tightening force of the motor axes are calculated,the contact force between the axial clearance and the motor shaft is extracted,and the stress and life of the motor shaft under different axial clearance are analyzed.(4)According to the simulation results,the inclination angle of universal coupling is reduced,and the structure optimization scheme of the roller table system is preliminarily designed.Through the simulation analysis of the roller table system,the cause of the fatigue fracture of the roller table motor shaft is found,and the structure is improved.Make the stand roller can restore smooth operation,ensure the surface accuracy of rolled steel,improve the efficiency of the roller table system.