BOTTOM-HOLE UNIT Russian patent published in 2010 - IPC F04B47/04 F04F1/06 

FIELD: engines and pumps.

SUBSTANCE: proposed unit comprises electrically driven deep-well pump with housing and intake chamber with its inlet accommodating intake valve and its outlet accommodating delivery valve communicated with tubing string on delivery side, and hydraulic drive. Note here that there is a web arranged in intake chamber, at the bottom of hydraulically driven pump housing, to divide said chamber into pumping chamber with intake and delivery valves and control chamber. Note also that hydraulic drive is provided with hydraulic cylinder arranged above intake chamber representing cylindrical barrel with bottom turned upside down relative to hydraulic drive housing. Hydraulic cylinder working chamber communicates via bypass channel with control chamber. Hydraulic cylinder plunger is arranged to axially move driven by rigid link connected with tubing casing. Plunger outer cylindrical lateral wall is sealed with respect to hydraulic inner cylindrical wall embracing the former. Note that between inner space of hydraulic cylinder below plunger and circular space formed between hydraulic cylinder outer part and hydraulic drive housing inner parts. Note also that between pumping chamber and control chamber spaces are formed filled with buffer fluid to make hydraulic lock. Mind that working chamber, control chamber and bypass channel are filled with drive fluid.

EFFECT: higher reliability.

2 dwg, 5 cl