The screw pump is a rotary pump (see pump) that relies on the volume change and movement of the mesh space formed by the pump body and the screw to transport or pressurize the liquid. The screw pump is divided into a single screw pump, a twin screw pump and a three screw pump according to the number of screws. The picture shows a twin screw pump. When the driving screw rotates, the driven screw that meshes with it is rotated together, and the screw meshing space volume at one end of the suction chamber is gradually increased, and the pressure is lowered.
The liquid enters the volume of the meshing space under the pressure difference. When the volume is increased to a maximum to form a sealed chamber, the liquid is continuously moved axially within the sealed chambers until one end of the chamber. At this time, the screw meshing space volume at one end of the discharge chamber is gradually reduced, and the liquid is discharged. The working principle of the screw pump is similar to that of the gear pump, except that the gear is replaced by a screw in the structure. The table shows the characteristics and application range of various screw pumps. The screw pump has small flow and pressure pulses, low noise and vibration, and self-priming capability, but screw processing is difficult. The pump has a single suction type and a double suction type, but the single screw pump has only a single suction type. The working principle of the screw pump The screw pump is a positive displacement pump, which uses the pump body and the intermeshing screw to separate the screw teeth into a cavity that is isolated from each other, so that the suction port and the discharge port of the pump are separated.
When the screw pump is working, the active screw rotates in a certain direction, and the driven screw also rotates. The cavity formed by the tooth cavity at the suction point is enlarged from small to large, and sucks into the liquid. When the cavity is increased to a maximum, the teeth and the teeth are closed. The oil in the closed cavity moves along the axial discharge end. At the discharge port, the volume of the cavity gradually becomes smaller, and the liquid is discharged.