Sealed motor driven valve

The present invention relates to electric motor-driven valves, and particularly, to so-called canned motors preferably using a threaded armature extension to drive the valve core within a valve body and commutated by Hall-effect devices, with the windings and Hall-effect devices ordinarily being enclosed within a second, atmosphere-tight enclosure. The valve housing may comprise a two-way valve, a three-way valve, a pressure-balanced valve or a multi-port valve, as used for example in heat exchange or industrial refrigeration. Disclosed is a motor operated valve including a valve body with an inlet and outlet and a valve seat therebetween. A valve core reciprocates between open and closed positions by threads of the valve core cooperating with threads on a shaft which rotates with the armature of the motor. The armature has a plurality of spaced apart permanent magnets, a bearing assembly, and is enclosed by a magnetically transparent enclosure closed at one end and hermetically sealed at its other end to the valve body. Lying closely outside the enclosure is a drive stator that includes drive windings and plural Hall-effect devices for commutation of the windings.