ELECTRICALLY DRIVEN DOWNHOLE UNIT Russian patent published in 2014 - IPC F04B47/08 

FIELD: engines and pumps.

SUBSTANCE: proposed unit comprises downhole motor articulated with driven pump. Hydraulic actuator comprises two pistons articulated by intermediate rod. Rod and rod seals are arranged at end face of every piston. Hydraulic control valve is communicated with driven pump and hydraulic actuator. Two areas between every piston and rod seal are communicated via throttle and/or valve opening at preset pressure to make closed barrier space. Outside of at least one rod, right behind its seal, pump including housing and valves are arranged. Every said barrier space areas is communicated via check valve with working fluid compensator communicated with discharge pipe.

EFFECT: higher reliability, longer life.

2 cl, 2 dwg