Working principle of screw conveyor
When the spiral shaft rotates, due to the gravity of the material and the frictional force generated with the groove wall, the material can only move forward along the groove bottom of the conveyor under the push of the blades, as if a nut that cannot rotate moves in translation along a rotating screw. The main driving force of the material is the upward and forward force exerted by the spiral blades when rotating in the axial direction along the tangential direction of the blades.
In order to keep the screw shaft in a favorable tension state, the driving device and discharge port are generally placed at the same end of the conveyor, while the feed port is placed as close to the tail of the other end as possible. The rotating spiral blades push the material for transportation, and the force that prevents the material from rotating together with the spiral conveyor blades is the weight of the material itself and the frictional resistance of the spiral conveyor housing to the material. The surface shape of the blades varies depending on the type of material being conveyed, including solid surface, belt surface, and blade surface. The screw shaft of the screw conveyor has a thrust bearing at the end of the material movement direction to provide axial reaction force to the screw along with the material. When the machine is long, an intermediate suspension bearing should be added.