Design And Study Of Magnetorheological Damper For Mine

With the development of national economic and the promotion of coal cleaning technology,the demand for coal is also increasing,and the requirements for the performance and service life of the vibrating screen are also raised.In addition,because of its easy operation and high production efficiency,the vibrating screen is also increasingly used in chemical,port,and power industries.When the vibrating screen is in practice,there is resonance phenomenon in the process of opening and stopping,which not only makes the support spring overload,shortens the life of the structure,causes the related connector difficult,and also produces larger dynamic load on the foundation,so that the surrounding buildings are subjiect to vibration hazards.Therefore,while ensuring the large processing capacity and high working efficiency of the vibrating screen,how to extend the support life of the vibrating screen and reduce the harm of resonance has become the key to research.In this paper,the problem of vibration isolation of vibrating screens is studied,and the magneto-rheological vibration damping technology is proposed to be used in vibration isolation of vibrating screens.The magnetorheological damper with variable damping and continuously adjustable damping force is designed and manufactured,and the working characteristics of vibration screening based on the magnetorheological damper are investigated by experiments.Through the experimental investigation of the working characteristics of the vibrating screen based on the magnetorheological damper vibration isolation,a new method is provided for the study of the vibrating screen vibration isolation technology.The composition of magnetorheological fluid is described and the rheological effect is explained intuitively by the rheological mechanism.The performance evaluation index are analyzed showing that shear yield sterss is the most important performance of magnetorheological fluid.It was pointed out that the magnetic-induced yield stress was the most important index to evaluate the performance of MR fluid.The characteristics of constitutive models of magnetorheological fluids are summarized,and it is pointed out that this paper is based on the Bingham model to design and calculate magnetorheological dampers.The working mode and applicable occasions of the magnetorheological damper are described.Based on the Bingham constitutive model,the theoretical damping force model of magnetorheological damper based on the plate model and shear valve working mode is established.The composition,characteristics and influencing factors of the damping force of magnetorheological damper are summarized.According to the technical parameters of vibrating screen and the space of vibration damping support,the overall design scheme of the magnetorheological damper is determined,and the geometric structure and magnetic circuit structure of the damper are optimized by the traditional method and combined design method.The rationality of magnetic circuit design is verified by Ansys simulation software.The Simulink dynamic simulation model of the magnetorheological damper is established,the performance of the damper is estimated,and the performance experiment of the magnetorheological damper prototype is carried out by the MTS810 material testing machine.The experimental results provide some reference for the practical application of the magnetorheological damper.The experimental test rig based on the vibration screening of the magnetorheological damper is built,and the experimental research on the resonance phenomenon during the opening and stopping of the vibrating screen is carried out.The experimental results are compared with the traditional metal spring and ROSTA spring,and the results are summarized,which provides the experimental basis for the application of the magnetorheological damper in vibration isolation.