CENTRIFUGAL SCREW PUMP Russian patent published in 2010 - IPC F04D9/04 F04D13/04 

FIELD: engines and pumps.

SUBSTANCE: pump includes housing, impeller with a hub installed on the shaft which is installed on the bearing protected with a sealing, and a screw. Inside the hub there installed are intermediate and internal shafts. Between edges of those shafts there installed is spring. On one end of internal shaft there installed is the first screw which is fixed on that shaft with a front conical nut. On the opposite end of internal shaft there fixed is rear conical nut with impeller of the first hydraulic turbine. On ends of intermediate shaft there installed is the second screw and impeller of the second hydraulic turbine. Nozzle device of the first hydraulic turbine is installed in conical cavity inside the shaft, and that of the second hydraulic turbine - in the cavity inside the hub. In the latter there are through holes connecting the cavity of impeller to cavity in the hub; inside the shaft there are three cavities divided with a partition with a hole. Rear cavity of the shaft is interconnected with cavity between bearing and sealing. Screws are made so that they can rotate in opposite directions.

EFFECT: improving cavitation properties of pump.

2 cl, 3 dwg