Research On Vibration Isolation Of Vibrating Screen Based On Magnetorheological Fluid Damper

With the theory of sustainable development of coal put forward,there is an increasing demand for vibration screening coal technology,making how to guarantee the performance of the vibrating screen and the service life of the vibrating become the top priority.The practical application of the vibration screen has the resonance problem,which not only affects the service life of the vibration screen,but also causes damage to the surrounding buildings under serious condition.How to ensure the lifespan of vibrating screen and reduce vibrating screen resonance have a great research prospect.In this paper,a continuous adjustable damping force shearing damper valve type is designed and produced based on the intelligent material – MRF because the MRF has the magnetorheological effect with high shear yield stress,transient response of the reversible and the advantages of easy control.The damper valve will be used for vibration isolation of the vibrating screen.Through test research,a new perspective for vibration isolation studies will be provided.This paper focuses on the following aspects:The basic concept,composition and rheological mechanism of magnetorheological fluid are expounded.This paper elaborates several constitutive relation models widely used in magnetorheological fluid and their advantages and disadvantages.The study also points out the analysis and design of magnetorheological damper based on Bingham constitutive model.Several working modes of magnetorheological damper are described and the damping output of magnetorheological damper in shear valve mode is theoretically analyzed by Bingham constitutive model.The working principle of magnetorheological damper is also illustrated.The structural parameters and magnetic circuit design of magnetorheological damper are designed as well.The magnetic field finite element simulation of the designed magnetic circuit was carried out by Maxwell software.The magnetic force distribution of the damper and the law of magnetic induction intensity in the damping channel were analyzed.The paper also discussed the influencing factors of magnetic field intensity in the gap of the damping channel.The damper is assembled and the performance of the damper is studied by the MTS810 testing machine.The experimental results provide a reference for the subsequent application of the magnetorheological damper.The damper is assembled on the vibrating screen for vibration isolation test and compared with the spring,ROSTA and other vibration isolation modes.The results show that the damper is effective in vibration isolation and the resonance decreases,providing a basis for the application of magnetorheological damper in vibration isolation of different vibrating screens.There are 60 figures,15 tables and 83 references in this dissertation.