SUBMERSIBLE MULTISTAGE CENTRIFUGAL PUMP Russian patent published in 2016 - IPC F04D13/10 F04D29/02 F04D29/22 F04D29/44 

FIELD: machine building.

SUBSTANCE: invention relates to machine building and can be used in downhole electric centrifugal pumps for oil production. Submersible multistage centrifugal pump includes housing (1), shaft (2), stage (3) consisting of impeller (4) and guiding unit (5), made of cast iron with following composition, wt%: carbon - 3.2-3.9; silicon - 0.2-1.0; manganese - 0.5-0.8; chromium - 0.1-0.5; copper - 0.8-1.5; aluminium - 1.7-4.0; titanium - 0.0-0.3; phosphorus - not more than 0.2; sulphur - not more than 0.02; iron - balance. Surface of wheel (4) and apparatus (5) include nitrated low-temperature nitriding layer. Wheels (4) are installed on shaft (3) and have a lower axial support wheel with bearing surface, blades, hub with external radial support surface, upper axial support with bearing surface. Apparatus (5) are installed in housing (1) by means of cylindrical holder, comprise support collar with bearing surface, hub with inner radial support surface, cylindrical shell, vanes, lower support surface. Support surface of lower axial bearing wheel (4) and support collar vehicle (5) have hard facing. Hard facing of support surfaces of lower axial support wheel (4) and support collar vehicle (5) are in contact, forming a friction pair. External and internal radial support surface of hubs of respectively wheel (4) and apparatus (5) are in contact by nitrided layers to form a radial support of shaft (3).

EFFECT: higher reliability, durability and overhaul period and reduced cost.

6 cl, 4 dwg