US Patent 7255073 Electromechanical valve actuator beginning of stroke damper

An electromechanical valve actuator having a beginning of stroke damper to damp the impact between the armature stem and the valve stem as the valve is opened. The beginning of stroke damper includes an armature stem defining a stem passage and a valve stem including a lash compensator defining a cavity communicating with the stem passage. An oil pocket may be provided within the cavity to absorb the impact of the armature stem before the armature stem contacts the valve stem as the valve is opened. The lash compensator is configured so that the cavity has a discharge rate sufficient to ensure that the cavity completely drains at approximately the time the engine valve reaches the full open position.