ROD PUMP UNIT Russian patent published in 2012 - IPC F04B47/00 

FIELD: engines and pumps.

SUBSTANCE: rod pump unit includes tubing string 1 with locking support 2, upper cylinder 3 of small diameter and lower cylinder 4 of larger diameter, two hollow moving plungers - upper plunger 5 of small diameter and lower plunger 6 of larger diameter, rod string 7 connected to upper end of upper plunger 5 by means of adapter 8 with openings, filter 9, clutches 10, 11. To lower end of upper plunger 5 by means of adapter 12 connected is rod 13 with plunger tappet 14 fixed on it, sand cleaner 15 and valve 16 functioning for suction and delivery. Ball valve 17 with ball-retainer 18 are installed in cavity of upper plunger. Space between upper cylinder and plunger is sealed with elastic sleeve 19 fixed on plunger by threaded holders 20, 21 and by vacuum booster 22.

EFFECT: reducing power consumption due to load decrease on drive mechanisms, increasing well rate, reducing quantity of underground repairs.

2 dwg