Actuator for engine valve with tooth and socket armature and core for providing position output and/or improved force profile

An actuator for use with an engine valve, the valve having a valve stem and a valve head, the valve head sized to cover a valve seat of an internal combustion engine, the actuator comprising:

• a first and second coil receiving a coil current and opposed along a common actuation axis and spaced apart by an actuation distance;
• a first and second core incorporating the first and second coils, respectively, and presenting opposed core faces across the actuation distance;
• valve stem supports holding the valve stem aligned with the actuation axis for movement along the actuation axis;
• an armature plate extending in a plane perpendicular to the actuation axis and attached to the valve stem for movement therewith along the actuation axis;
• at least one spring attached to the armature plate to bias the armature plate to a neutral position between the core faces;
• and
• wherein the armature plate and a core face of at least one core have a mating tooth and socket extending parallel to the actuation axis, the tooth and socket sized to provide a more constant relationship in the attractive force between the core and the armature as a function of separation distance between the core face and the armature for a constant coil current.