Pump casing made of sheet metal

摘要

A pump casing made of sheet metal comprises a casing jacket having a cylindrical cup shape, an end plate formed at one side of the casing jacket, a casing flange formed at the other side of the casing jacket and a projecting portion radially outwardly bulged so as to have a volute portion. The end plate is axially outwardly bulged so as to have an arcuately curved surface, the projecting portion has a substantially semicircular cross section, and the base portion of the projecting portion is located on the extension of the arcuately curved surface of the end plate so as to provide continuity from the end plate to the projecting portion. With the above structure, there is no portion where a great deal of bending stress caused by stress concentration is generated, and the pump casing has a sufficient strength and rigidity against not only piping forces but also internal pressure in its entirety.