Accurate Realization of Follower Motions in High-Speed Cam-Follower Mechanisms

Traditionally, cam-follower systems are designed by assuming a constant camshaft speed. Nevertheless, all cam-follower systems, especially high-speed systems, exhibit some camshaft speed fluctuation (despite the presence of a flywheel) which causes distorted follower motions and subsequent dynamical problems. The authors previously proposed two methods to overcome these problems: (i) the synthesis of inertially compensated cams [2], of which the motion law is adapted to the camshaft speed fluctuation and (ii) input torque balancing using an inverted cam mechanism [3]. The present paper unifies the notation and dimensionless analysis of the previous papers and compares both methods by applying them to the same design example. Furthermore, the analysis in the presence of friction is enhanced. Both methods are shown to yield accurately realized follower motions, even in the presence of a considerable amount of friction, despite the fact that friction is ignored during the design process.