Design and experimental evaluation of an electromechanical engine valve drive

In conventional internal combustion (IC) engines, engine valve timing is fixed with respect to crankshaft angle. Flexibly controlled valve timing offers significant improvements in fuel efficiency, engine performance and emissions. One way to achieve variable valve timing (VVT) is by using an electromechanical valve drive (EMVD). In this paper, we describe the design and experimental evaluation of a new EMVD comprising an electric motor coupled by a nonlinear mechanical transformer to a resonant valve-spring system. Experimental results demonstrate that a 3.3 ms transition time adequate for 6 krpm engine speed, reasonable power consumption, and low valve seating velocity are obtained with the design.