Patent attributes
A multi-stage vane-type positive displacement pump used for lifting fluid from oil wells has stages disposed on a common shaft. Each stage has a rotor, a stator, separating vanes, working chambers, a lower cap with inlet ports, and an upper cap with outlet ports. The rotor is in the form of a cam. The stator is formed from two concentric sleeves situated on a base and having an annular gap therebetween. Slots are provided in the inner sleeve and in the base for the movement of the vanes. The vanes are connected to one another by a synchronizing element. The ports are situated opposite the chambers, either side of the vanes. The end faces of the caps of adjacent stages are conjoined to form an annular cavity, which communicates with the gap of the preceding stage. The aim is to increase the reliability of the pump, to simplify the design and to reduce the manufacturing cost thereof while enabling the pumping of fluids with a high content of abrasive particles.
