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

FIELD: engines and pumps.

SUBSTANCE: screw centrifugal pump comprises vessels 20, 21, 23, centrifugal impeller 2 with hub 3, installed on shaft 1, and screw 5. Screw 5 is installed on additional shaft 6 with the possibility of axial displacement and is spring-loaded in the end at the side of pump outlet by spring 19, installed on shaft 6. Inside hub 3 of impeller 2 there is an internal cavity 10, where nozzle unit 9 and hydraulic turbine impeller 8 are placed, forming cavities 11, 12 upstream nozzle unit 9 and downstream hydraulic turbine impeller 8. Hydraulic turbine impeller 8 is connected via reducer 18 with additional shaft 6. In centrifugal impeller 2 on various diametres d1, d2 there are two groups of holes 15, 16, one of which communicates cavity of centrifugal impeller 2 to cavity 11 upstream nozzle unit 9, and the other one - to cavity 12 downstream hydraulic turbine impeller 8.

EFFECT: improved cavitation properties of pump.

2 cl, 1 dwg