Continuous Variable Valve Duration (CVVD)
CVVD (Continuous Variable Valve Duration) is a device to improve performance and efficiency by altering valve opening time while reducing gas emission.
CVVD varies cam angular speed by location using eccentricity of rotation axis. The changed cam angular speed alters valve opening time.
Convergence of CVVT (electric Continuously Variable Valve Timing) and CVVD improves efficiency and performance by controlling valve opening/closing independently.