Desmodromic valve designs for improved operation smoothness, stability and package space

This invention relates generally to drive mechanisms that convert uni-directional rotational motion to reciprocal translation. An example of such a mechanism is a desmodromic drive, one use of which is as an actuator of an intake and/or an exhaust valve in an internal combustion engine. A desmodromic drive () for imparting reciprocal translation to a valve () has a cam ring () that rotates about an axis (), a follower () that reciprocates with axial motion as the ring rotates, an endless cam track () on the ring, and rollers () on the follower that ride along the cam track as the ring rotates. A follower guide () guides the follower for axial. Rollers () constrain the follower against rotation on the follower guide.