It is mainly used for sieving and grading of materials in various systems in the grinding process of the flour milling industry, and also for sieving and grading of fine-grained materials and powders in other industries. Adopt double seal bearing structure, three springs plus core balanced bearing axial force, integral disassembly and assembly of motor, shell-type transmission steel frame, supplemented by hinged hole bolt connection, prolong service life, double sealing of internal passage of screen box, anti-channeling powder , Screen grid without stop and without supporting net increases the screening area and improves the screening effect. The device has one invention patent and four utility model patent technologies.