Pump arrangement and method for producing a containment shell for the pump arrangement

A pump arrangement, comprising:

• a pump casing having an interior space;
• a containment can having a central longitudinal axis and being arranged to hermetically seal a chamber in the interior space;
• an impeller shaft;
• an impeller arranged on an impeller end of the impeller shaft;
• an inner rotor arranged within the containment can on an opposite end of the impeller shaft;
• and
• an outer rotor arranged radially outside of the containment can and axially located to interact with the inner rotor,
• wherein
• the containment can has a base with at least one bead configured to project into the chamber,
• a center region of the containment can base is unsupported along the central longitudinal axis on an impeller side of the containment can base,
• the at least one bead is arranged away from the central longitudinal axis of the containment can with a spacing to the central longitudinal axis of the containment can such that a ratio of an inner radius of the containment can to a distance between a radially outer edge of the at least one bead to the central longitudinal axis of the containment can is between 1.3 to 1.6, and
• the base of the containment can includes a substantially spherical-segment-shaped cap region and a rim region arranged as a transition region between a main body of the containment can and spherical-segment-shaped cap region, the substantially spherical-segment-shaped cap region being continuously curved between one side of the rim region to a diametrically-opposite side of the rim region in regions away from the at least one bead.