1. Screw pump is the use of screw rotation to suction and discharge liquid. The figure shows a cross-sectional view of a three-screw pump. In the picture, the middle screw is the active screw which is driven by the prime mover. The screw on both sides is the driven screw, which rotates reversely with the active screw. Active screw driven screw thread are double-headed thread. Due to the mutual engagement of the screws and the tight fit of the screw with the inner wall of the liner, one or more sealed spaces are separated between the suction and discharge of the pump. As the screw is rotated and engaged, these sealed spaces are constantly formed at the suction side of the pump, sealing the liquid in the suction chamber therein and continuously displacing in the axial direction of the screw from the suction chamber to the discharge end to be closed in the respective spaces Continued discharge of liquid, like a nut in the screw rotation is constantly moving forward, as the case, which is the basic working principle of the screw pump. 2. The working principle of the screw pump is: When the screw pump is working, the liquid is inhaled and then enters the sealed space surrounded by the screw thread and the pump shell. When the driving screw rotates, the screw pump sealing volume is increased under the extrusion of the screw tooth to improve the screw pump Pressure, and axial movement. Since the screw is rotating at a constant speed, the flow of liquid out is also uniform.