Screw pump, also known as "screw pump" and "Archimedes screw pump". A pump that uses the rotation of spiral blades to cause the water body to spiral upward along the axial direction. It consists of shaft, spiral blade and shell. When pumping water, place the pump tilted in the water so that the inclination angle of the main shaft of the water pump is smaller than the inclination angle of the spiral blades, and the lower end of the spiral blades is in contact with the water. When the prime mover drives the screw pump shaft to rotate through the speed changer, water enters the blades and rises along the spiral flow channel until it flows out. It has a simple structure, is easy to manufacture, has a large flow rate, small head loss, high efficiency, and is easy to repair and maintain. However, it has low lift and low speed, and a transmission device is required. Mostly used in irrigation, drainage, and lifting of sewage and sludge, etc.