RODLESS BOREHOLE PUMP Russian patent published in 2016 - IPC F04B47/06 

FIELD: oil industry.

SUBSTANCE: invention relates to oil producing industry and can be applied for well oil extraction by well pumps. Rodless pump 1 is installed on submersible motor 2. Pump consists of cylinder 3, hollow plunger 4, pump stick 5. Upper part of cylinder is equipped with retaining valve, containing valve body 6 with seat 7 in its lower part. In retaining valve shutoff element 8 is arranged with relative longitudinal mobility and with longitudinal centering ribs 9. Hollow plunger 4 is arranged in cylinder 3 on mandrel 10 equipped with hardened seat ring 11. Bottom of hollow plunger 4 is furnished with hardened bushing 12. Pump stick 5 connects submersible motor 2 with mandrel 10. Stick 13 is attached to upper part of mandrel 10 and passes through inner cavity of shutoff element 8, with possibility of sealing gaps between them.

EFFECT: improved operational reliability.

1 cl, 3 dwg