BOTTOM-HOLE OIL PUMP Russian patent published in 2011 - IPC F04B47/00 

FIELD: engines and pumps.

SUBSTANCE: bottom-hole oil pump includes cylinder 1 with suction valve 2 and plunger 3 arranged in cylinder 1 with discharge valve 4. In inner cavity of plunger 3, below its upper pointed edge 5 there installed is coupling sleeve 6 having upper 7 and lower 8 conical surfaces. Lower 8 conical surface of coupling sleeve 6 touches inner conical surface 9 of plunger 3. Upper conical surface 7 of coupling sleeve 6 is pressed with conical surface 10 of nut 11 to inner conical surface 9 of plunger 3. Plunger 3 includes inner cavity 15 and divides the cavity of cylinder 1 into suction cavity 12 and discharge 13 cavity. Coupling sleeve 6 attaches plunger 3 to rod string 14.

EFFECT: higher operating efficiency of bottom-hole pump owing to preventing the penetration of mechanical impurities into the gap between plunger and cylinder due to proper tightness of plunger walls to cylinder walls.

1 dwg