弛张筛浮动筛框与主动筛框合理质量比的研究

Research on reasonable mass ratio of floating flip-flow screen frame and main screen frame

为了丰富国内弛张筛关键结构部件的设计参考依据,对弛张筛浮动筛框与主动筛框的质量比进行了研究。建立了弛张筛有阻尼的力学模型,绘制了主、浮筛框幅频特性曲线,分析了质量比对弛张筛振幅稳定性的影响,设计并制作了一台半工业性弛张筛,进行了试验验证。结果表明:剪切弹簧刚度不变时,质量比增加,主、浮筛框的幅频特性曲线左移,主、浮筛框振幅降低;弛张筛加入物料后,振动系统的二阶共振频率会发生漂移,应选择合适的质量比,使其漂移幅度10%以内;在设计条件能满足的前提下,应增加质量比,以减少物料质量对弛张筛振幅的影响,为弛张筛的合理设计提供参考依据。

In order to enrich the reference for the design of key structural components of flip-flow screen,the mass ratio of the floating flip-flow screen frame to the main screen frame is studied.The mechanical model of flip-flow screen considering the effect of damping is established,the amplitude-frequency characteristic curves of the main and floating screen frames are plotted,and the influence of the mass ratio on the amplitude stability of flip-flow screenis is analyzed.Then,a pilot scale flip-flow screen is devised and manufactured.Its performance is verified by experiments.The results show that in the case of constant shear spring stiffness,the increase in the mass ratio leads to a left shift of the amplitude-frequency characteristic curves of the main and floating screen frames,and a decrease in the amplitudes of the main and floating screen frames.Moreover,adding material to the flip-flow screen results in a drift of the second-order resonance frequency of the vibration system.It is shown that an appropriate mass ratio should be selected to limit the magnitude of the drift within 10%.The present study suggests that the mass ratio is increased to reduce effect for mass of added material on amplitude of flip-flow screen,provided that the design conditions can be satisfied.This study provide reference for the reasonable design of flip-flow screen.