CENTRIFUGAL SCREW PUMP Russian patent published in 2017 - IPC F04D29/66 F04D29/41 F04D9/04 

FIELD: engines and pumps.

SUBSTANCE: centrifugal screw pump comprises a housing (1) with inlet (2) and outlet (3), a pump head (4), a partition (5), a shaft (6) an impeller (7) and a screw (8). The housing (1) and the pump head (4) are connected to the bearing housing (9). There is a high-pressure chamber (10) between the partition (5) and the pump head (4) which is connected to the outlet (3) by passages (11). The partition (5) forms a hub plate (13) seal (12) of the impeller (7) and groove seals (14), (15) of the barrel (16), the separating chamber (17) is positioned between them and connected to the chamber ( 10) by the holes (18). The partition (5), the plate (13) and the barrel (16) form a discharging chamber (19) which is connected to the impeller (7) entrance chamber (21) by the holes (20) in the plate (13). There is a drain cavity (22) behind the seal (15) which is separated from the bearings (24), (25) by the shaft (6) seal (26). The cavity (22) is connected by drain passages (23) which are made in the pump head (4).

EFFECT: exclusion of environment air entering the pump and the deterioration of its anti-cavitation properties by maintaining the chamber pressure close to the pressure at the pump outlet during the pump operation.

3 cl, 1 dwg