摘要 |
An electromechanical valve apparatus has an electrical winding and a magnetic flux circuit defining a flux path therefor which includes a plurality of adjacent magnetic segments. The segments include a generally cylindrical center segment with a fluid passage, an end segment, an outer segment and a magnetic armature member. At least one of the segments is physically translatable within the valve apparatus along the flux path to adjust a portion of one of the magnetic segments that is in the flux path and the extent of an air gap adjacent the translatable segment. The apparatus includes a non-magnetic seat member which is located near or at the point of highest flux density along the longitudinal axis through the electrical winding. The armature is preferably an elongated member with its closed end located within the electrical winding near the non-magnetic seat member. The seat member and armature are enclosed within a chamber defining body such as the bobbin. In an alternative embodiment, a flat disc member is located at the base of the armature. The flat disc is retained within the base of the armature. When no current is flowing in the winding, the flat disc member rests against an armature seat formed in the chamber defining body and prevents leakage of air from the fluid chamber. A further alternative embodiment allows ready calibration of the valve apparatus via a calibration fixture adopted to translate one of the magnetic segments within the flux path.
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