PUMPING UNIT Russian patent published in 2001 - IPC

FIELD: oil producing industry. SUBSTANCE: proposed pumping unit is designed for lifting liquids from depth, for instance, from wells. It can be used in vertical and inclined directional wells. Pumping unit has drive, pump with housing secured on lower end of tubing, suction and delivery valves, inlet branch pipe and at least one bellows with connecting elements between valves. Pumping unit has hollow rod arranged in housing and inside bellows and installed for axial displacement. Side surface of rod has perforated section. Pump housing has guide bushing-sealing device. Pump inlet branch pipe has mounting washer secured on lower end of hollow rod. Pump inlet valve is located in upper part of inlet branch pipe, and delivery valves are arranged in housing. Pump drive is mounted on upper end of tubing, being connected with hollow rod means of tie-rod installed for passing through sealing device of tubing. Perforated section of side surface of hollow rod is located in its lower part, being in length less than summary length of pump bellows by value of axial travel of hollow rod. Bellows are provided with connecting elements. They form hermetically sealed pump chamber together with connecting elements, pump housing and mounting washer of inlet branch pipe. EFFECT: increased efficiency, improved reliability and increased service life of pumping unit. 5 cl, 1 dwg