基于幅频特性的振动弛张筛工况调试的研究

Research on debugging condition of vibrating flip-flow screen based on amplitude-frequency characteristics

振动弛张筛工况的合理性与稳定性对其筛分性能和处理能力有很大的影响。本文基于双质体有阻尼线性振动理论建立反映其振动特性的力学模型,通过数学和动力学分析,揭示其主要动态参数:剪切弹簧阻尼比ξ2、偏心质量矩Mr、剪切刚度k2x和质量比μ(浮动筛框与主动筛框的质量比)对工况点幅频特性的影响规律,并通过试验进行分析验证。结果表明:工况频域内可以忽略阻尼比对相对振幅的影响;质量比约为0.3时既不会过多增加参振质体质量,又可以降低物料对振动系统的影响;调整剪切刚度,使其工况位于稳定的频域;增减偏心质量矩,可线性增减其相对振幅。提出了一种合理的调试方法,先调节质量比,再调整剪切刚度,最后增减偏心质量矩,保证工业弛张筛在达到合理相对振幅时工况点位于稳定的频域区间,完善振动弛张筛在工况调试时的理论和技术支持。

The rationality and stability of the vibrating flip-flow screen have a great influence on its screening performance and processing capability.In this paper,we established a mechanical model to reflect its vibration characteristics based on the theory of double-body damping linear vibration.Through mathematical and dynamic analysis,the main dynamic parameters such as:damping ratioξ2,eccentricity mass moment Mr,shear stiffness k2x,and mass ratioμ(mass ratio of floating screen frame and main screen frame)on the amplitude-frequency characteristics of the operating point are verified through tests.The results show that the damping ratio has negligible influence on the relative amplitude in the frequency domain,and the mass ratioμ≈0.3 is appropriate,which could not increase the mass of the vibrating flip-flow screen,but also reduce the impact of the material on the vibration system.Adjusted shear stiffness could make the working condition in the stable frequency domain;Increasing or decreasing the eccentricity mass moment can increase or decrease the relative amplitude linearly.The method of first regulatingμ,then adjusting k2x,and finally increasing or decreasing Mr is proposed to ensure that the industrial flip-flow screen is located in a stable frequency domain when a reasonable relative amplitude is achieved.This improves the theoretical and technical support of the vibrating flip-flow screen.