PUMPING UNIT Russian patent published in 1999 - IPC

FIELD: oil producing industry; equipment used for pumping liquid out of wells. SUBSTANCE: pumping unit has housing with rod mounted inside it which is engageable with working member of working pump, rod reciprocating mechanism, distributor with change-over mechanism, delivery and drain mains brought out to distributor and connected with drive of pump. Housing is provided with cover having hole where rod is mounted. Rod reciprocating mechanism is made in form of two bellows mounted on two sides relative to cover and connected with rod. Cavities of these bellows are communicated with delivery and drain mains. Change-over mechanism of distributor is made in form of pusher which may be engageable with distributor fastened with slider fitted on rod. Slider is engageable with retainer secured on cover. Pusher is passed through slot provided in plate secured on rod. EFFECT: enhanced reliability and increased service life of pumping unit due to bellows mechanism used together with change-over mechanism. 1 dwg