Electromagnetic valve actuator for a valve of an engine

An apparatus for actuating a cylinder valve of an engine, the cylinder valve having a closed position, a full open position and a neutral position between the closed and full open positions, said apparatus comprising:

• an armature moveable in a direction of an axis, said armature including a sleeve portion extending in the axial direction and a disk portion connected with a circumferential inner periphery of the sleeve portion and adapted to be fixed to the cylinder valve;
• a pair of springs biasing the armature toward a valve-neutral position corresponding to the neutral position of the cylinder valve;
• a pair of electromagnets attracting the armature for moving the cylinder valve to the closed and full open positions, said electromagnets being disposed in an axially opposed relation to the armature, said electromagnets including a pair of axially spaced magnetic cores;
• and
• a permanent magnet retaining the armature for holding the cylinder valve in the closed and full open positions;
• wherein the sleeve portion of the armature cooperates with the permanent magnet to define a first air gap radially extending therebetween and cooperates with each of the magnetic cores to define a second air gap radially extending therebetween, and the disk portion of the armature cooperates with each of the magnetic cores to define a third air gap axially extending therebetween and variable with the axial motion of the armature.