BOREHOLE PUMP UNIT Russian patent published in 2015 - IPC F04B47/06 

FIELD: engines and pumps.

SUBSTANCE: claimed pump unit comprises housing filled with oil, resilient jacket and reversible motor with drive shaft engaged with the first gearing composed of rolling screw and nut. Bearings are fitted on said screw-nut gearing. Hollow rod coupling said nut with said rod is sealed in the housing. This unit is equipped with two screw-nut gearings running in opposite directions by their helical surfaces. Said screw-nut gearing is engaged directly with the motor shaft to make the first gearing. It is engaged with external hollow rod and, further, with external hollow bar. The latter covers the sliding nut of second gearing engaged with the internal hollow rod and internal bar engaged therewith to make a bidirectional drive for plunger pump provided with section and delivery valves. Pump cylinders house the plungers sliding in opposite directions.

EFFECT: longer life, enhanced performances due to application of new bidirectional two-way design.

8 cl, 5 dwg