ELECTROHYDRAULIC BOREHOLE UNIT Russian patent published in 2013 - IPC F04B47/08 

FIELD: engines and pumps.

SUBSTANCE: proposed unit comprises borehole motor articulated with drive pump. Hydraulic actuator comprises two pistons interconnected by mid rod. End face of every piston is furnished with rod and its seal. Hydraulic control valve is communicated with drive pump and hydraulic actuator. Two chambers between every piston and rod seal are communicated to make closed barrier space. Outside, at least, of one rod, under its seal, pump devices are arranged and include housing and valves. Filter communicated with barrier space is arranged inside the housing of one pump and/or discharge pipe.

EFFECT: higher reliability, longer life.

7 cl, 7 dwg