Study On Structural Vibration Properties Of Thevertical Screw Conveyor On The L-screw-type Continuous Ship Unloader

Screw ship unloader is a kind of large special continuous bulk dischargingmachine,it is very important in the modern ports and bulk cargo terminals logisticswith lots of advantages such as high discharging efficiency,eco-friendly,wideapplicability,Light weight, simple structure,etc.Compared with the traditional screwship unloader,the new L-screw ship unloader discussed in this paper make a lot ofinnovations,including feeding mode,intermediate support way,material circulationway,conveyor support structure and pitch balance system,those innovationsimproved the discharge efficiency, reduced the energy consumption.The vertical screw conveyor is the core component of the new L-screw shipunloader,the performance of it affects the work efficiency of the whole screwship,The study about it can be divided into two aspects:the vertical transmission ofmaterial and the properties of structure dynamic.Among them,the study of structuredynamic properties is still in the foundation stage because of its largestructure,complex load combination and unpredictable dynamic behavior.This paperstudy the vibration properties of the conveyor structure based on the vertical screwconveyor by using the dynamics theory and finite element analysis method.The mainwork includes the following aspects:1、Study the initial form of dynamic load and vibration mechanism of verticalscrew conveyor structure,determine the generate of the incentive and its action, andgives a calculation formula of it.2、Establish the lumped parameter discrete model and dynamic equations of thevertical screw conveyor structural response system,select X direction vibration as theresearch object,solve the dynamic equation, obtain the response of arbitraryincentive and intrinsic properties of discrete model.3、Establish the finite element model of the vertical screw conveyor by applyingthe Ansys software,analyze the the static load of the model,figure out the static andmodal properties and find out the eccentric vibration of motor and screw axis is themain reason for the conveyor vibration.4、By extending the analysis cycle,apply the transient dynamic analysis method to the study of vibration effect,figure out the displacement response and stressresponse under vertical motor rated speed,the result shows that the vibration of theconveyer will eventually reach the steady state,and the vibration of the structure inthe Y direction is serious than in the X direction.Study the vibration responseamplitude distribution by using the harmonic response analysis technology, find outthe structure resonance speed range, and provide a theoretical basis to select suitableconveyor work speed.