To provide a multistage pump capable of obtaining the stable sealing performance and accuracy in intermediate sealing, and using a multipurpose inexpensive O-ring.
In this multistage pump comprising a plurality of intermediate casings formed by press-molding a steel plate, the intermediate casings 2 are respectively provided with a cylindrical side part 21, a stepped flat part 23 abutted on an axial end face of the adjacent intermediate casing, a stepped side part 23 axially extended from the stepped flat part 23, and a bottom part 24 extended to a radial inner side from the stepped side part 24, the bottom part 25 of the intermediate casing 2 is provided with an escape plate 30 abutted on an inner peripheral face of the cylindrical side part 21 of the adjacent intermediate casing 2 at its outer peripheral end face, and a space for mounting the O-ring 40 is formed by the escape plate 30, the stepped side part 23, a stepped flat part 23 and the inner peripheral face of the cylindrical side part 21 of the adjacent intermediate casing 2.
KAJIWARA KENICHI
ITO SHOJI
MORI KIKUICHI
ISHIKAWA AKI
FUJIWARA TETSUTARO
