Dynamic Characteristics Of Flip-Flow Screen Surfaces Based On Dual-motors Driving

Flip-flow screen is a screening machine which is widely applied in occasion of the dry deep screening of moist fine coal,because it has the advantage of low energy consumption,little noise,and high screening efficiency.However,it is assembled with single-motor for traditional flip-flow screen,in which floating box performs forced vibration by spring damping.It is difficult for this driving type to regulate and control vibrant amplitudes of two boxes respectively,because the amplitudes of machine can change according to the feeding amounts.Additionally,in aspect of screen surfaces of flip-flow screen,the coupling analysis between particles and reflexible screen panels cannot be conducted by numerical simulation.As a result,it is not clear for motion of particles on flip-flow screen surfaces and dynamic screening performance.In this paper,based on the flip-flow screen with dual-motors driving,the solution of dynamics-discrete element method coupling analysis can be adopted to study dynamic behaviors with screen machine-screening panels-particles coupling model.In order to ensure stable screening efficiency,to improve screening effectiveness,and to reveal the dynamic characteristic of flip-flow screen surfaces,the specific research work and achievements of this paper are as below:Firstly,the dynamic model for three-degree-of-freedom with biaxial diploid is built in the light of Lagrange equation,and steady complex solutions of forced vibration are solved,As a result that work frequency of near resonance area are obtained;Under stable condition,the effect of phase difference of eccentric shafts on that of two boxes is researched;The system of flip-flow screen with dual-motors driving is calculated using RecurDyn to verify resionablity of aforementioned model.Secondly,the FEM models of flip-flow screen surfaces are built by ANSYS,the effect of design parameters on screen surfaces vibration are analyzed,which are then imported into MBD software to set up rigid-flexible screen machinescreen panels coupling model;Dynamic analysis of flexible panels are studied,and the coupling model is compared with the model of elastic compression bar;The effect of deflection shape of elastic screen surfaces and tensional amount on the motion of screen surfaces are investigated.Finally,the motion trajectory?jumping rules for a particle and particle swarm on the screen surfaces are researched based on rigid-flexible model.The piecewise linear interpolation is adopted to achieve approximate flexibility for flexible panels,the accuracy and reliability of this method are then confirmed via comparision with Catenary curve.We introduced DEM(Descrete Element Methods)in the work of screening process,and established DEM-MBD coupling model.The influence of vibrant parameters on screening effenciency,production ratio and casting intensity are studied.The main research work and conclusions of this paper can provide thoery basis and reference for following works,such as the dynamic analysis of flip-flow screen surfaces,the revelation of projection and collision of particles,and control algorithm synergistically for dual-motors driving.