CENTRIFUGAL SCREW PUMP Russian patent published in 2010 - IPC F04D9/04 F04D13/04 

FIELD: engines and pumps.

SUBSTANCE: centrifugal screw pump includes housings 5, 17, 19, impeller 2 with hub 3, which is installed on shaft 1, and screw. Inside hub 3 there installed is intermediate and internal shaft 6, 8. On one end of internal shaft 8 there installed is the first screw 10 which is fixed on shaft 8 with conical nut 11 on conical surface of which there made is wheel 12 of the first hydraulic turbine, on periphery. On ends of intermediate shaft 6 there installed is the second screw 13 and impeller 15 of the second hydraulic turbine. Nozzle assembly 14 of the second hydraulic turbine is installed in cavity inside hub 3. In the latter there made are through holes 25 attaching cavity of impeller 2 to cavity 26 in hub 3. After wheel 15 of the second hydraulic turbine there made is overflow return channel of pumped product to cavity 18 before wheel 12 of the first hydraulic turbine in the form of through axial hole 28 in internal shaft 8 and conical nut 11. Screws 10, 13 are made so that they can be rotated to opposite sides.

EFFECT: improving cavitation properties of pump.

3 cl, 3 dwg