Working principle: the rotating screw blades move the materials to the screw conveyor for conveying. The force that makes the materials not rotate with the screw conveyor blades is the weight of the materials and the friction resistance of the screw conveyor shell to the materials. The surface types of spiral blades welded on the rotating shaft of screw conveyor include solid surface type, belt surface type, blade surface type and so on according to different conveying materials. The screw shaft of the screw conveyor has a thrust bearing at the end of the material movement direction to give the axial reaction force to the screw with the material. When the captain is long, an intermediate suspension bearing should be added.