CENTRIFUGAL PUMP STAGE, CENTRIFUGAL PUMP AND USE OF PUMP STAGE Russian patent published in 2018 - IPC F04D1/06 F04D13/08 F04D29/42 F04D29/16 F04D7/04 

FIELD: motors and pumps.

SUBSTANCE: group of inventions relates to a centrifugal pump stage, in particular a submersible type pump. Pump stage for a centrifugal pump comprises impeller unit (10) having axial hub (11), diffuser unit (20) and cover (30). Impeller unit (10) is supported floating inside diffuser unit (20). Shim ring (40) is associated with impeller unit (10) and is sustained in sliding support on washer (27) housed in a fixed position in correspondent seat (26) of diffuser unit (20) of an adjacent pump stage. Impeller unit (10) is in sliding contact with cover (30) along annular portion (13a). In the start-up or shut-off phase, a slight play is provided between portion (13a) of impeller unit (10) and cover (30), such that the hydraulic leakage losses are minimised without contact.

EFFECT: inventions are aimed at providing a high level of performance and prolonged wear-resistance under any operating conditions.

9 cl, 3 dwg