Systems, methods, and devices for valve stem position sensing

• Main Authors: Nielsen, Douglas John, Hildebrandt, Mark William
• Format: Patent
• Language: English
• Published: 06.11.2018
• Subjects: BLASTING; CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES; ENGINE PLANTS IN GENERAL; HEATING; LIGHTING; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; STEAM ENGINES; WEAPONS

A linear variable differential transformer (LVDT) for monitoring engine valve position is disclosed. The system includes a valve guide having an elongated recess through it. The engine valve has a valve head and a valve stem with two adjacent materials having different magnetic properties meeting at an interface. The valve stem fits and moves linearly within the valve guide, and the valve head closes an engine combustion chamber. It also includes monitoring coils within the valve guide that create a signal related to the position of the interface within the valve guide. An engine control unit (ECU) is coupled to the monitoring coils and receives and analyzes the signal from the monitoring coils to determine operation of the valve.