PUMPING UNIT Russian patent published in 2014 - IPC F04B47/02 

FIELD: engines and pumps.

SUBSTANCE: invention relates to oil industry and can be used for mechanised oil extraction with the help of downhole sucker-rod pump. Proposed pumping unit comprises frame, rack with rod string secured thereto. Said rack engages with the gear fitted on reduction gearbox output shaft composed by double reduction gearbox and simple three-link planetary mechanism operated in summing mode with permanent drive of pinion carrier and variable drive to epicyclic gear. Note here that reverse gearing is ensured at gear shifting with close gear ratios. Counterweights have elastic linkage with either rack bottom end or drum secured at output shaft. Telescopic mechanism can be incorporated to increase pump working stroke.

EFFECT: simplified and perfected design, decreased weight and overall dimensions.

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