Screw pump is a new type of liquid conveying machinery, with the advantages of simple structure, safe and reliable operation, convenient use and maintenance, continuous and uniform liquid discharge, and stable pressure. A pump that uses the rotation of a screw to pump liquid, which is best suited for absorbing viscous liquids. Screw pump is a single screw pump, its main working parts are eccentric screw spiral (known as the rotor) and the inner surface of the double helical screw bush (called stator). Its working principle is that when the motor drives the pump shaft to rotate, the screw rotates on its own axis on the one hand, and on the other hand, it rolls along the inner surface of the liner to form a sealed chamber of the pump. Each revolution of the screw, the liquid in the sealed cavity is pushed forward by one pitch. As the screw rotates continuously, the liquid spirally presses from one sealed cavity to the other sealed cavity, and finally the pump body is extruded. As can be seen from the above working principle, screw pump has the following advantages: 1) wide pressure and flow range. A pressure of about 3.4-340 kgf / cm 2, a flow rate of up to 18,600 cm 3 / min; 2) a wide range of fluid types and viscosities to be transported; and 3) a high rotational speed ; 4) good suction performance, self-priming capability; 5) uniform flow rate, low vibration, low noise; 6) compared with other rotary pumps, the gas and dirt into the less sensitive; 7) solid structure, installation Easy to maintain. The disadvantage of the screw pump is that the screw machining and assembly requirements are higher; the performance of the pump is sensitive to changes in the viscosity of the liquid.
