PUMP UNIT FOR LIQUID PUMPING TO WELL Russian patent published in 2011 - IPC F04B47/06 

FIELD: engines and pumps.

SUBSTANCE: pump unit includes reversible motor 1 with hydroprotection, actuator 2, rolling screw-nut and piston pump 3 connected to lines of low 9 and high 14 pressure. Unit is installed in casing 4 connected to line 9 and includes pump 3 of double action, the working cavities 5 and 6 of which are connected by means of two branch pipes 11 and 12 to cavity of casing 4 and high pressure line 14 through the valve block 10 installed outside the casing. Valve block 10 includes pairs 16, 17 of valves, which are connected to branch pipes 11 and 12. Oil-filled actuator 2 has fixed erection method and is hydraulically balanced with pressure in pump 3.

EFFECT: increasing the head, capacity and service life of pump unit.

3 cl, 4 dwg