Pump impeller and coupling magnet structures

摘要

Cylindrical impeller-coupling magnets of the ceramic type in magnetically-coupled centrifugal pumps according to the disclosure are encircled by guard banding to aid in retaining the cylindrical configuration in cases of cracking and fissuring in the magnet body occasioned by exposure to superheated liquids in the impeller chamber. Supplements to the subject: the banding may be characterized as (1) non-metallic or metallic and non-magnetic; (2) multiple narrow bands or a single wide banding embracing the cylindrical aspect of the magnet in its entirety; (3) the cylindrical aspect of a cup-shaped metallic jacket with a bottom portion additionally shielding one axial end of the magnet; (4) the cylindrical aspect of a totally-enclosing encasement; (5) of thin cross section to lie upon the cylindrical surface (6) of moderately thick ring-like stock seating in recessing grooves in the cylindrical surface; (7) in all forms constrained against projection more than slightly into the magnetic air gap.