CENTRIFUGAL SCREW PUMP Russian patent published in 2011 - IPC F04D1/04 

FIELD: engines and pumps.

SUBSTANCE: pump includes housings 3, 9, 10, 16, screw 12, centrifugal impeller 4 with hub 5 having inner cavity, which is installed on shaft 1. Shaft 1 is installed in bearing 2 protected with seal. Screw 12 is installed on shaft 1 so that it can slide. Hydraulic turbine 13 is installed before screw 12 and rigidly attached to it, and additional screw 14 is installed before hydraulic turbine 13 and has external banding ring 15 rigidly attached to impeller 4. On additional screw 14 there can be installed inner banding ring. Inner diametre of additional screw 14 is 0.4…0.95 of its outer diametre D₁, and outer diametre of hydraulic turbine 13 is 0.4 to 0.6 of outer diametre D₁ of additional screw 14. Inside hub 5 there is inner cavity 27 and through holes 28 attaching cavity 27 of hub to cavities 8 of impeller 4. Inside holes 28 centrifugal flow controls 36 are installed.

EFFECT: improving cavitation properties of pump included in turbine-pump unit, and removing axial forces from the shaft.

5 cl, 8 dwg