working principle When the screw shaft rotates, due to the gravity of the material and the friction between the material and the groove wall, the material can only move forward along the groove bottom of the conveyor under the push of the blade, which is like the translational movement of the non rotatable nut along the rotating screw [3]. The main driving force of materials comes from the upward and forward force of materials along the tangent direction of the blade when the spiral blade rotates axially. In order to make the screw shaft in a more favorable tension state, the driving device and discharge port are generally placed at the same end of the conveyor, and the feed port is placed near the tail of the other end as far as possible. The rotating spiral blade moves the material for transportation, so that the material does not rotate with the spiral conveyor blade. The force is the weight of the material and the friction resistance of the spiral conveyor shell to the material. The surface types of blades include solid surface type, belt surface type, blade surface type, etc. according to different conveying materials. The screw shaft of the screw conveyor is provided with thrust bearing at the end of the material movement direction to give the axial reaction force of the screw with the material. When the captain is long, the middle hanging bearing should be added.