Finite Element Analysis And Structure Improvement On Vibrating Screen Box Of Large Flour Milling Unit

Vibration screen is a kind of sieving machine, which has been developed quickly inrecent thirty years. also has been widely used in mining, metallurgy, railway, agricultureand other fields. Among them, the linear vibrating screen with high production efficiency,good effect of classification, and convenient maintenance has been widely used. In theprocess of operation, the vibrating screen box is always under the effect of cyclic loading,and screen frame deformation and fracture structures such as beam damage. The servicelife of the current domestic large-scale linear vibrating screen and trouble-free runningtime relative to the level of foreign and larger gap. How to reduce the stress level ofvibrating sieve, eliminate stress concentration so that the stress distribution inhomogeneous to improve reliability, avoid fatigue damage of vibrating screen, prolongthe service life of the vibrating screen is great significance.For the problems,such as easy breaking of the side plate of vibrating screen andrelatively short service life of the TQLZ self-balancing vibrating screen of Hebei PingleGroup,analysis for the vibrating screen box was carried out by using finite element in thispaper.The analysis consist of modal,static and fatigue analysis,then the reason of screenbox damage was found out and improvement suggestions were put forward.In the modalanalysis,the results of extracting natural freqrencies and pattern of vibration before15order of the box shows that the working frequency is far away from its natural freqrencyand resonance won’t happen.There is a great stress concentration existed in the box viastatic stress distribution.The strength of box can be improved remarkably by adding sheetmetal to the basepalce of box and stress concentration can be reduced obviously.Based onthe above,the results of fatigue analysis on the box show that fatigue damage may happento the screen box because of the stress is still exceed the fatigue limit although thestrength of the box is improved. Therefore, improvements were carried out on theinstallation of the motor fixed plate of vibrating screen, i.e.,the connection pattern ischanged from bolt plus welding. The stress concentration reduced and the fatigue damagedisappeared after improving the structure via further analysis.Through the study of the modal analysis of the scale vibrating screen, static analysisand fatigue analysis, provides a theoretical basis for the structure improvement of screenbox. By reducing local stress concentration phenomenon of screen box, avoid the fatiguedamage, increased reliability and service life of the vibrating screen. Not only for this type of vibrating screen provides theory basis for improving design, also for other typesof vibrating screen design provides a good way to study.