Abstract:Coworkers and authors have put forward the concept of multidimensional parallel vibrating screen, and made prototype design and experimental analysis. However, the movement process of materials on the multidimensional vibrating screen and the problems of ideal sieve surface movement have not been solved yet. In this paper, the material movement process and the ideal screen surface movement of the multidimensional parallel vibrating screen were studied. First of all, two important indexes were imported, including the dispersion degree and layering rate, and the effect of six single degree of freedom (DOF) vibrations of screen surface on the material dispersion and layering process based on discrete element method (DEM) were analyzed, so the four single degree of freedom vibrations of screen surface were optimized which were more conducive to the material dispersion and layering process, that was three translations x, y, and z along the length, width and height of screen surface respectively, and a rotation γ around the normal of screen surface. Among them, the effects of the x and y single degree of freedom vibrations of screen surface were particularly obvious. Then according to screening efficiency and impurity rate, screening process of material on the multidimensional vibration sieve was simulated based on various vibration movement forms consisted of the four single degree of freedom vibrations selected. The results showed that three translational and one rotational 4DOF vibration form xyzγ had the best screen permeability, which was selected as the ideal screen surface movement form. Finally, according to the ideal screen surface movement, a 3T-1R parallel mechanism was designed, the prototype was developed, and the screening test was carried out on the prototype. The work of this paper provided a solid theoretical basis for the design of the multidimensional parallel vibrating screen and the selection of the optimum screening parameters.
