Study On Strength And Self-excitation In The Main Driving System Of The Rolling Mill

To optimize the load distribution of each rolling mill of some factory, reduce the accident rate of machinery breakage and promote the quality and quantity of production, the carrying capacity of the main transmission system of the rolling mill must be accurately calculated. Slipper type universal coupling's fork joint and palm end are the weak parts of the main transmission system. In this article, the two parts' intensity values are obtained through finite element analysis . After making three-dimensional computer simulation analysis by ANSYS, the results show that the middle arc of the fork joint in loaded side and the intersection of fork bore and the arc are the danger location, where the stress is largest and stress concentration is serious. Considering the limitation of element number and calculation time, the grid of whole model is sparse and some details including round angle can not be shown. Therefore, sub-model method is used and has the danger region's grid refined then the biggest danger position's stress is calculated, on this basis of the above calculation, the carrying capacity of the first rolling mill can be calculated accurately.On the other hand, when the roller works, self-excited vibration may arise sometimes, torque amplification factor (TAF) increases, the part may be spoiled and roll steel surface quality can be affected badly. The dissertation studies the phenomena and characteristics of self-excitation, deduces those phenomena belong to nonlinear non-conservative autonomous steady-state periodic movement. From this, a mechanics model is set up to establish its movement equation with space, vibration boundary and random friction coefficients are concerned, and the corresponding procedure is made with VC++ by using numerical method. It can be educed the factors' infection on system vibration. While space increases, the amplitude rises; and random friction coefficient affects amplitude and frequency greatly. The procedure can be used expediently and the conclusion is reliable.The conclusions of the dissertation accord with practical situation. The results can guide practical production and the optimal design of machinery system of this type.