Single screw pump as the name suggests that there is only one screw in the pump. Following the customary name of China's screw pump industry, the screw of a single screw pump is called the rotor, and the screw bushing is called the stator. The stator driven by an external power source meshes with the stator to form a sealed cavity separating the suction cavity and the discharge cavity, so that the pump can work effectively.

At present, the single-screw pump produced in the world, the rotor and the stator of the meshing pair, the vast majority of products or the single-headed spiral rotor and the double-headed inner spiral stator meshing. In the past ten years, some foreign manufacturers have developed single-screw pumps that engage the rotor of the double-headed spiral and the stator of the three-headed internal meshing spiral, and the individual manufacturers have mainly developed to mass production and sales. China also has a small number of manufacturers to develop, is still in the development stage.

Double screw pump is driven by synchronous gear, connected with two sets of helices, no contact between helices, no mechanical friction, long service life.

Single screw pump is rubber sleeve stator and rotor, the use of transport medium lubrication, friction leads to easy damage to the rubber sleeve, the general life of about half a year, the transport of pure lubricating medium is more suitable, if there are impurities will greatly reduce the service life.

However, its disadvantages are also very obvious: higher processing accuracy requirements, increase the difficulty of processing, especially if the processing accuracy is not enough, it will affect the uniformity of the rotor and the stator, so that the above advantages no longer exist; Moreover, there are many processing hours and high production costs, which is the reason why there is less production at present.

Of course, it is also possible to manufacture a single screw pump with more rotor and stator helical heads, such as a pump composed of a three-headed spiral rotor and a two-headed internal spiral stator, but the requirements for manufacturing accuracy are higher, and the flow rate is not always increased with the increase in the number of spiral heads, so it has little practical significance. Although the meshing pair of rotor and stator with more spiral heads has not been applied in single screw pumps, it has been widely used in the field of screw drilling tools for petroleum machinery.