Type A1 3V three-screw pumps are designed for pumping non-corrosive liquids with kinematic viscosity of 0,1 to 60 cSt, having lubricating capacity, containing no abrasive impurities and with temperatures of the transferred liquids within 100°C.
By its operating principle, this is a positive displacement pump.
The pump consists of the following principal parts and assembly units: the body with lids and end seal. Inside the body, a casing has a yoke 5 with three adjacent cylindrical bores in which the three shafts are placed, the two driven shafts serving to tighten the driving shaft.
The special profile of the helix ensures mating of the screws; their threads are double, the main drive screw is left-handed and the driven screws are right-handed.
As the screws are spinning, vacuum is created in the suction chamber and the pumped liquid fills the roots of the screw thread that interlock in spinning.
The hydraulic part design provides for off-loading of axial force from the screws by feeding the pumped liquid under working pressure through the bores in the screws to the load-relieving pistons which are integral parts of the screws. The residual axial force is taken by the bearing on the main drive shaft and by the bushing - on the driven shafts.
The pumps are equipped with safety valves for protection of the pump and the system against higher-than-rated pressure.