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

FIELD: oil producing industry. SUBSTANCE: pump is designed for use in production of oil and it relates to deep-well pumps set into action by sucker rod string. Proposed pump has housing with cylinder, hollow plunger placed in cylinder, valve-spool mechanism and mechanism to transform rotation of sucker-rod string into reciprocation of plunger. Ring projections in form of fixed bushings are made at both ends on cylinder surface. Plunger in arranged between bushings and hollow rod is passed through plunger. Plunger is secured on rod for reciprocation. Interacting end faces of plunger and cylinder projections are made at angle to axis of housing, and their contacting ring surfaces are screw-like. Inclined end faces of plunger are parallel to each other, and inclined end faces of cylinder projections are turned on axis of housing through 180^o relative to each other. Valve-spool mechanism is made in form of two diametrically opposite grooves on surface of plunger which serve for alternate communication of pump spaces, radial hole in cylinder, with housing space, and further on, with ambient medium, and grooves on projections of cylinder which serve for alternate communication of pump spaces, through radial holes in rod, with rod space and further on with tubing string. Radial holes in rod communicating through groove with upper pump space (said space in Drawing is shown as joined) are made on opposite side of rod relative to radial holes communicating through groove with lower pump space. EFFECT: improved reliability of mechanism transforming rotation of sucker-rod string into reciprocation of pump plunger. 2 cl, 4 dwg