Shaft coupling for a molten metal pump

Abstract

An apparatus for pumping molten metal is disclosed. The apparatus includes a submergible pump housing, a rotatable impeller disposed within the pump housing, an impeller shaft having one end coupled to the impeller and extending through an opening in the pump housing, a motor-driven rotating drive shaft and a coupling member engaging an end of the drive shaft and an opposite end of the impeller shaft and a shear pin extending between the coupling member and one of the drive shaft and impeller shaft thereby coupling the drive shaft and the impeller shaft. Preferably, the coupling member is a female coupling member having two shaft receiving openings receiving the drive shaft end and the second end of the impeller shaft and includes a pair of aligned transverse apertures. A graphite pin is inserted through the coupling member apertures and extends through a transverse bore near the end of the impeller shaft. The graphite pin is held in place by a wire wrapped around an outer periphery of the coupling. The wire includes looped ends which are adapted to be twisted and thereby holding the pin in place.

Dependencies are inferred from the claim text.