Study On Vibration Characteristics And Parameter Optimization Of Double-mass Linear Vibrating Screen

The vibrating screen is mainly used for screening of materials and has a wide range of applications in industrial and agricultural production.Due to the lack of theoretical guidance,there are many problems in the process of working,such as the unstable operation of the screen body and how to reasonably select the parameters in the screening process,which requires dynamic analysis to provide theoretical basis for the use and manufacture of the vibrating screen.Based on the dynamic characteristics of the double-mass linear vibration screen,the equivalent mass of the leaf spring is obtained by using the principle of energy method.Considering the stiffness of the spring in the horizontal and vertical directions of the lower mass,the differential equation of motion of the double-mass linear vibration screen with and without damping is derived by using Lagrange equation,and the natural frequency of the system is obtained by using the characteristic of infinite amplitude of resonance.The influence of relevant parameters on the dynamic amplification coefficient is discussed.The amplitude of the upper and lower mass of the vibrating screen during the start-up process is simulated by using MATLAB software.The dynamic equation of variable mass of the vibrating screen is deduced.The amplitude stability of the upper and lower mass of the vibrating screen under the condition of linear increase,linear decrease and mass fluctuation of the material mass is analyzed.The working stability of the vibrating screen when the exciting force deviates from the center of mass is preliminarily studied.When the vibrating screen is screening material,the material's non-linear force(mainly the friction force when sliding and the impact force when falling)will also have a greater impact on the stability of the system.The differential equations of motion of materials in forward sliding,reverse sliding and throwing motion are derived,and the initial and termination angles of each motion state are calculated.And the first approximate solution of the system considering the material's non-linear force is obtained by using the harmonic balance method,and its numerical simulation is carried out.Taking the production efficiency in unit time as the objective function,the vibration screen was optimized with the frequency of the exciting motor and the angle of the shrapnel installation as variables.After optimization,the production efficiency of the vibration screen was obviously improved compared with that before optimization.