MULTISTAGE ROTARY PUMP STAGE Russian patent published in 2010 - IPC F04D1/06 F04D13/10 F04D29/44 

FIELD: engines and pumps.

SUBSTANCE: pump stage comprises distributor 1 accommodating impeller 2. Distributor 1 consists of consists of cylindrical case 3, upper disk 4, lower disk 5 with vanes 6 arranged there between to make return channels. Inclined vanes 7 are arranged opposite outlet of impeller 2, between upper disk 4 of one stage and lower disk 5 of the next stage. Inner edges of vanes 7 are arranged along screw curves on cylindrical surface enveloping impeller 2. Outer edges of vanes fair with inner surface of case 3 along screw curves with their inclination to horizontal line reduces along liquid flow direction. Adjacent vanes 7 are arranged overlapping. Note here that distances in horizontal planes between vanes 7 in their overlapping part, in direction from inner to outer edges, increase at opening angle of 6-10°. Cylindrical screen 8 adjoining lower disk 5 of the next distributor is attached to inner edges of upper part of vanes 7.

EFFECT: minimised hydraulic losses, higher head due to stabilised working fluid flow between stages.

3 cl, 7 dwg