ROTARY MULTISTAGE PUMP STAGE Russian patent published in 2014 - IPC F04D13/10 F04D29/42 

FIELD: engines and pumps.

SUBSTANCE: invention relates to pump engineering, particularly, to downhole multistage pumps used for oil extraction and water feed into a productive oil formation to keep up and to up the formation pressure. A pump stage consists of a closed impeller with a drive disc, blades, driven disc, a distributor including a cylindrical case, top and bottom discs with blades there between to make return channels, and spiral ribs. The spiral inclined ribs are arranged on the cylindrical case inner lateral surface opposite the impeller outlet. He spiral ribs are arranged in a shaped insert made of an elastomer and secured on the distributor cylindrical case surface.

EFFECT: invention is aimed at elongation of the life of stages owing to higher wear resistance of the distributor sidewall opposite the flow exit from the impeller.

3 cl, 3 dwg