SCREW CENTRIFUGAL PUMP Russian patent published in 2011 - IPC F04D9/04 F04D13/02 

FIELD: engines and pumps.

SUBSTANCE: screw centrifugal pump comprises vessels 5, 21, 23, 35, centrifugal impeller 2 with hub 3, installed on shaft 1, which is installed on bearing 4, protected with seal 36, and screw 10. Inside hub 3 there are intermediate and inner shafts 6, 8 installed. At the end of shaft 8 at the side of pump inlet there is the first screw 10 installed and fixed on shaft 8 with front conical nut 11. At the end of shaft 6 at the side of pump inlet there is the second screw 15, at the opposite end of shaft 6 there is an impeller 12 of hydraulic turbine 13. Inside hub 3 there is reducer 17 installed, connecting shafts 6, 8. In hub 3 there are through holes 28, connecting wheel cavity 2 with cavity in hub 3. At the back end of wheel 2 there is the back seal 26, under which there is an unloading cavity 27. Shaft 1 is arranged as hollow, comprising middle and back cavities 29, 30, between which there is an intermediate bearing 20. In shaft 1 between bearing 4 and seal 36 there are radial holes 37, coming out into back cavity 30. Screws 10, 15 may be arranged with the possibility of rotation in opposite directions.

EFFECT: improved cavitation properties of pump.

2 cl, 2 dwg