Screw pair

The company established the production of the most popular screw pairs for plastering stations and concrete pumps for pouring floors. The screw pair is made of high-quality materials using a unique technology. The inner part of the stator is made of a strong, elastic rubber compound, which extends the service life of the screw pair, in addition, the manufacturer LLC “NVO “SZGTV” managed to make the best price offer without compromising quality. Screw pairs of our production are 10-15% cheaper than the average market price and are not inferior to imported counterparts.

The principle of operation of the screw pair
The screw pair consists of a rotor (screw) and a stator (a rubber clip in a metal housing), inside which the rotor rotates. The rotor fits very tightly to the inner walls of the stator, which ensures a high working pressure of the screw pair up to 40 bar. When the rotor rotates, it moves both in a circle, and forward and backward. The solution enters the opening cavity of the screw pair and moves toward the solution sleeve. When the rotor rotates in the stator, the solution moves through the spiral channel of the stator. Thus, the mixture is pumped. The centers of rotation of the spirals, both of the stator and the rotor, are shifted by the amount of eccentricity, which makes it possible to create a friction pair in which, during the rotation of the rotor, closed hermetic cavities are created inside the stator along the entire axis of rotation. The performance of the screw pair depends on the volume of the closed cavity and the number of revolutions of the rotor, and the pressure in the screw depends on the number of stages, the number of closed cavities in the pump and the displacement voltage between the rotor and the stator. For screw pairs used in construction, the first Latin letter is the outer diameter of the stator housing: A = 40mm, B = 51mm, C = 59mm, D = 90mm, R = 114mm, T = 125mm. The second number is the eccentricity value, the larger the number, the more the volume of feed was fitted, the third number means the number of steps, i.e. the number of closed cavities per unit length of the screw pair

Let’s explain using the example of the D6-3 pair:
      • The letter D means the diameter of the stator
      • The number 6 denotes the eccentricity of the rotor in mm. The larger the number, the larger the supply.
      • The number 3 means the number of compression stages (the pressure increases by 10 bar for each stage).

Purpose of the screw pair The screw pair is a pumping device that ensures the movement of the solution to the place of use. The resource of the screw pair depends on the following factors: the number of revolutions, the type and quality of the solution, the height and distance of the supply, the diameter of the sleeve and the quality of the rubber mixture. The screw pump works with gypsum, cement-sand, cement-lime, adhesive, self-leveling and putty compositions. Depending on the tasks and the quality of the material, different screw pairs are installed.