Study On Dynamic Characteristics And Structure Optimization Of USLg Vibrating Screen

Vibrating screen is an indispensable machine in industrial production and processing.In the process of manufacture and application,it is easy to appear beam broken and side plate cracking because of strength and stiffness deficiency.These failures affect seriously the normal operation of production line.Traditional design method based on experience and safety factor can no longer accurately reveal the stress and strain distribution inside the structure of vibrating screen in the application process.Therefore,in order to guarantee the operation safety of large vibrating screen,it is very important to improve reliability and stability of vibration screen during operation process by advanced methods of high design level.This thesis focuses on USLg vibrating screen which is newly produced by a mine machinery Co.Ltd.The actual working condition is simulated by combining discrete element method with finite element method.Software ANSYS R15.0 and EDEM 2.6 are applied in the dynamic research on the structure of screen body and eventually in the optimization of vibrating screen.First,three dimensional model is built by Solidworks software based on the structure and working principles of vibrating screen.A mathematical model of three degrees of freedom is established according to three dimensional model.The vibration differential equations of vibrating screen system are established,and dynamic characteristics of vibrating screen are analyzed.Second,the vibration isolation spring is optimized and its optimal design parameters are obtained.According to the analysis on synchronous stability of dual motors vibrating screen,the reverse rotation synchronization conditions,measures of prevention and debugging of self-synchronous vibrating screen can be gained.Third,the vibration stratification of spherical particles and the sieving process are simulated using discrete element method.The impact force that particles materials act on the screen body in normal working conditon is analyzed.Then,the stress and strain distribution in four working conditions of vibrating screen is analyzed.The first tenth order natural frequency and vibration models are calculated by finite element software ANSYS.The frequency curves of displacement in some key nodes at several frequencies are getten.The transient dynamic analysis is carried out and verified by analytical statics.Finally,in order to solve the problem that the side plate and the beam in high stess are easy to breakdown in working process of large vibrating screen,the structure optimization design on vibrating screen is executed.The rigidity of vibrating screen and the stability of structure is increased,and the deformation is reduced after optimization.