OIL-WELL SUCKER-ROD PUMP Russian patent published in 2000 - IPC

FIELD: oil and gas producing industry; hydraulic machine building; handling of liquids containing abrasive admixtures, gases, paraffin. SUBSTANCE: proposed pump has cylinder with hollow plunger installed in cylinder for movement and made of elastoflexible material. Lower part of rod-valve is made in form of cone mating with conical end face of plunger lower part playing the part of delivery valve. Axial travel at upward and downward movement of plunger provided. Rod-valve is connected to pump rod by means of transfer bushing whose contact profile is made mating to profile of conical end of plunger upper part. Conical bulge is located higher that contact profile of rod-valve and plunger. Sealing between plunger and pump cylinder is provided by pressure of liquid column onto inner walls of plunger. Thanks to it plunger, expanding, fits tightly to inner walls of cylinder which completely precludes passage of handled liquid and abrasive particles between plunger and cylinder. EFFECT: increased efficiency and service life of pump. 16 cl, 16 dwg