OIL-WELL SUCKER-ROD PUMP Russian patent published in 2003 - IPC

FIELD: manufacture of hydraulic machines; applicable in fluid recovery from wells. SUBSTANCE: pump has cylinder accommodating movably installed hollow plunger in form of rod with radial channels. Plunger external side surface has circular grooves with equilateral trapezium in cross- section whose small base faces gap in cylinder-plunger pair. Large base is hydraulically communicated through channels with plunger cavity. Installed in circular grooves are sealing members in form of unsplit rings from elastoplastic deformed material with cross-section in form of equilateral trapezium. Rings are located in circular grooves for engagement by their conical surfaces. Rod external surface is protected with anticorrosive coating with dielectric properties. Dirt collectors in form of cup-shaped collars are installed in cylinder with interference fit. Collar is relieved by radial channel. Cylinder may be strengthened by plastic deformation of metal. Additional channels in plunger structure are oriented onto collar cup. Number of packings on plunger increases with increase of pump lowering depth. EFFECT: improved conditions for packing in working gap and self-packing of packing members in circular grooves in course of pump operation, uniform gradual wear until full wearing, reduced wear of cylinder-plunger pair due to full exclusion of abrasive particles getting into working gap and excluded galvanic effect in pumping-out of highly aggressive fluids. 4 cl, 1 dwg