A custom-designed limited-angle actuator for an electromechanical engine valve drive Part I: Conceptual design

Abstract

Research has shown that variable valve timing (VVT) can improve significantly the performance of internal combustion (IC) engines, including higher fuel efficiencies, lower emissions, and larger torque outputs at each point of the engine map. To achieve independent and continuous VVT for each valve, an electromechanical valve drive (EMV) system was proposed previously, whose feasibility with low seating velocity had been demonstrated. In order to further improve the practicality of the EMV system, especially for a much smaller system package, a novel rotary actuator with limited angular range is proposed in this paper. Four main design challenges are discussed before a limited-angle actuator with a special yoke structure and a hollow basket-shaped aluminium-based armature is presented. Based on Maxwell simulation with optimized physical dimensions, the actuator is capable of meeting the time, power, torque, and size constraints.