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

FIELD: engines and pumps.

SUBSTANCE: pump includes housings 5, 24, 26, centrifugal impeller 2 with hub 3, which is installed on shaft 1 which is installed in bearing 7 protected with seal 39, and the first screw 15. Inside hub 3 on bearings 10, 11 installed so that cavity 31 is formed between them, intermediate shaft 9 is installed, and inner shaft 12 is installed inside it on bearings 13, 14. On shaft 12 end, on inlet side there installed is screw 15, and impeller 16 of the first hydraulic turbine 17 is fixed inside hollow shaft 1 on opposite end of shaft 12. The second screw 19 is installed on shaft 9 on inlet side between screw 15 and impeller 2, and impeller 20 of the second hydraulic turbine 21 is installed on other end of shaft 9. Through holes 32 are made in hub 3 and connect cavity 31 to cavity 6 of impeller 2. Rear seal 29 is installed on rear end of impeller 2, and unloading cavity 30 is made under it. Bearing 14 is installed inside nozzle diaphragm 22 of hydraulic turbine 21. In shaft 1 between bearing 7 and seal 39 there are holes 40 opening to cavity 34. Holes 40, 32 and cavities 30, 41, 34, 33, 23, 31 are made so that leakages through seal 29 lubricate all the bearings and actuate hydraulic turbines 17, 21.

EFFECT: improving cavitation properties of pump and providing unloading of axial forces.

2 cl, 4 dwg