Primary pole piece for a solenoid actuator

摘要

A primary pole piece (PPP) for an electrical solenoid linear actuator includes an inner skirt portion extending axially from a radial flange portion and having a substantially uniform cylindrical thickness and a non-uniform axial length. The skirt is formed into a plurality of "saw teeth" or other axially-extending and circumferentially tapered elements separated by axially extending notches or similar axial inlets along the terminal skirt edge. Whereas in the prior art the magnetic flux is intensified radially by conical formation of the skirt, in the present invention the magnetic flux is intensified azimuthally by being collected in and directed to terminal flats of the saw teeth. The entire PPP may be net-formed by conventional powdered metal press/sintering, requiring no post-forming machining. Preferably, the molded PPP is conventionally sintered to increase density and is impregnated for plating.