DOWNHOLE ELECTRICALLY DRIVEN PLUNGER PUMP Russian patent published in 2015 - IPC F04B47/06 

FIELD: engines and pumps.

SUBSTANCE: pump comprises housing with downhole motor fitted therein. Plunger is arranged in the casing with its top part fitted in pump casing and locked therein while its lower part features diameter corresponding to that of pressure pipe and is tightly jointed therewith. Pump casing features diameter smaller than that of the pipe and is arranged in protective jacket with filter to make the chamber of fluid pumping. Motor output shaft is provided with bush with lengthwise grooves on the surface located in cylindrical chamber made at plunger lower end. Grooves are made at plunger cylindrical chamber inner surface. Balls are fitted in said grooves to make a sliding axial joint Plunger centre has one or more closed helical grooves. Plunger housing is provided with ball pushers locked thereat to allow articulation between plunger and its housing and plunger reciprocation. Plunger housing mid part has radial channel while blind radial channel and circular bore are made in said plunger. Plunger housing upper part has pressure chamber that makes the pump working cylinder. Radial blind channel of the plunger is connected with the pump working cylinder. Pump working cylinder is connected with pipeline pressure pipe via discharge valve.

EFFECT: higher reliability and efficiency, longer life.

1 dwg