(19)
(11) EP 0 267 445 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
07.02.1990 Bulletin 1990/06

(43) Date of publication A2:
18.05.1988 Bulletin 1988/20

(21) Application number: 87114884.7

(22) Date of filing: 13.10.1987
(51) International Patent Classification (IPC)4: F04D 29/62, F04D 13/10, F04D 1/06
(84) Designated Contracting States:
DE ES FR

(30) Priority: 11.11.1986 IT 2229786

(71) Applicant: GRUPPO INDUSTRIALE ERCOLE MARELLI S.p.A.
Arzignano (VI) (IT)

(72) Inventors:
  • Mapelli, Lucio
    Cernusco sul Naviglio (MI) (IT)
  • Assi, Luigi
    Vimercate (MI) (IT)

(74) Representative: Forattini, Amelia et al
c/o Internazionale Brevetti Ingg. ZINI, MARANESI & C. S.r.l. Piazza Castello 1
20121 Milano
20121 Milano (IT)


(56) References cited: : 
   
       


    (54) Multistage pump for submersible electric pumps


    (57) A multistage pump for submersible electric pumps is described in which the axial anchoring and the centering of the stage body assembly are achieved by means of anchoring and centering elements consisting of projections (12a, 12c) provided in the outer ca­sing (1) of the pump. This allows a more solid and economical construction and a simplification of the assembly and disassembly of the pump, with a reduction of the number of inner structural locking elements.
    The floating-ring (24) sealing construction of the stage bodies (2) allows an improvement of the sealing effect and of the hydraulic performance.







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