DEEP-WELL PUMP Russian patent published in 2001 - IPC

FIELD: oil and gas extraction engineering; handling liquids containing abrasive impurities, gases, wax, and the like. SUBSTANCE: pump has barrel accommodating fixed hollow plunger made of flexible material, as well as valve-stem assembly whose conical bottom is mating conical end of bottom part of flexible bushing; valve-stem assembly functions as delivery valve and at the same time provides for axial displacement with flexible bushings moving up and down. Valve-stem assembly is secured to pump rod by means of transfer bushing whose contact outline is mating that of conical end of flexible bushing top part. Conical bulge is provided above contact outline of valve-stem assembly and flexible bushing. Desired tightness between flexible bushings and cylinder barrel is ensured due to pressure of liquid column on inner walls of flexible bushings. So, expansion of flexible bushings causes their tight fitting to inner walls of barrel thereby excluding any ingress of handled liquid and abrasive particles into clearance between flexible bushings and barrel. EFFECT: enhanced delivery and reliability of pump. 30 cl, 29 dwg