BOTTOM-HOLE OIL PUMP Russian patent published in 2012 - IPC F04B47/00 

FIELD: engines and pumps.

SUBSTANCE: bottom-hole oil pump includes cylinder with hollow plunger arranged in it and in the lower part of which a delivery valve is installed. Suction valve is installed in lower part of pump chamber. Pump is equipped with a bypass channel with a float valve provided with shutoff floating element and a seat located above it. Cylinder is stepped on the side of inner surface and bypass channel with shutoff floating element is provided in lower part of smaller step of cylinder above the pump chamber. One hole of the channel is connected to upper part of pump chamber and the other hole of the channel is connected to the well.

EFFECT: increasing the pump efficiency and reducing gas formation in pump chamber.

4 dwg, 7 cl