Screw pump, which is also called screw,is a type of rotor-toothed type. In it, the head of the injected liquid is formed by its displacement by screw rotors rotating inside the stator. They can be one or more, depending on the configuration of the device. Screw pumps are easily obtained from gears, and this is done by increasing the inclination of the teeth in them, as well as reducing the number of teeth on the gears. However, it is better to use the "original version" of the device.

Screw pump
The screw pump operates in accordance withfollowing principle. Pumping of liquid is carried out due to the fact that it moves between the screw grooves and the surfaces of the housing. The grooves are located along the axis of the screw. With their protrusions, they "walk" along replaceable grooves, which prevents the liquid from moving backwards.

Screw pump
The screw pump is used in a sufficiently widerange. It can be useful for pumping gas, steam, as well as their mixtures or liquids having varying degrees of viscosity. They were first introduced into production in the distant 1936. Due to the simplicity of the design, they can work freely even in the presence of mechanical impurities having viscous fluids at a pressure level up to 30 MPa. Such characteristics are very important for solving the mass of a wide variety of problems. Whole installations of screw pumps are actively used in wells intended for methane extraction from coal seams, as well as for pumping water from there. They are used to extract oil, water, and also for other wells.

The screw pump has interestingconstructive features. To increase the quality of seals, as well as to reduce the number of leaks in this type of adaptation, it is customary to use cylindrical or conical elastic bodies. The conical screw is pressed by the spring very reliably, in addition, the pressure of the pumped liquid plays a role here, which significantly reduces the number of leaks. Pumps having a metal casing are capable of withstanding significantly higher loads than their counterparts placed in elastic bodies. The device with a conical screw is able to work well and in a rigid case.

Screw pumps
The most common screw pump is a three-screw pump. In practice, its scope was the most extensive. This is due to certain specific advantages of this type of equipment:

- uniform supply of the substance;

- possibility for pumping liquids with solid additives, without any damage;

- possibility for self-absorption of liquids;

- high pressure at the outlet can be obtained without the mass of injection stages characteristic of other types of pumps;

- during operation, the device generates noise effects at a sufficiently low level;

- The pump mechanism is balanced very well.

This species also has certain disadvantages, which are considerably less than the advantages:

- a sufficiently high degree of complexity in the manufacture of this type of equipment, as well as its high cost;

- Lack of regulation of the working volume;

- use idle is simply unacceptable.