MULTISTAGE CENTRIFUGAL PUMP Russian patent published in 1994 - IPC

FIELD: production oil wells. SUBSTANCE: secured in the housing are guide vane assemblies. Besides that, shaft is mounted in the housing on which impellers with protective bushes between them are secured. Protective coating made of wear-resistance material are provided in areas where shaft is bent loads by loads acting on it at engageable zones of protective bushes and guide vanes assemblies. Protective coating are made of superhard material of group of self-fluxing chrome-nickel compositions and/or superhard nickel-aluminium material. Coating are made in form of shells manufacture separately. EFFECT: enhanced reliability. 3 cl, 1 dwg