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

FIELD: engines and pumps.

SUBSTANCE: screw centrifugal pump comprises vessels 5, 21, 23, 35, centrifugal impeller 2 with hub 3, installed on shaft 1, and screw 12. Shaft 1 is installed on bearing 4 protected with seal 36. Inside hub 3 there is intermediate shaft 6 installed on bearings 7, 8, and inside it there is inner shaft 9 installed on bearings 10, 11. At the end of shaft 9 at the side of pump inlet there is the first screw 12 installed, at the opposite end of inner shaft 9 there is impeller 13 fixed of the first hydraulic turbine 14, which is installed inside shaft 1. On shaft 6 at the side of input between the first screw 12 and centrifugal impeller 2 there is the second screw 16, at the other end of shaft 6 - impeller 17 of the second hydraulic turbine 18. In hub 3 there are through holes 28, connecting wheel cavity 2 with cavity 20 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 are bearings 8, 11. In shaft 1 between bearing 4 and seal 36 there are radial holes 37, coming out into back cavity 30.

EFFECT: improved cavitation properties of pump.

2 cl, 2 dwg