In a spring-actuated cam mechanism, a cam is driven by a pre-charged spring and revolutes only once to move the follower from start position to the end position.
The angular velocity of the cam is not constant in this mechanism as in many other cam-follower mechanisms. Therefore, the relationship between cam and follower motion should be obtained to design the cam which performs the desired follower motion.
In this research, all the linkages were considered as rigid bodies and the contact force between cam and follower was regarded as an external force to each cam and follower. The relationship of cam angle and follower displacement was obtained by eliminating the cam-follower contact force from the equations of motion. The desired follower motion was designed using a spline curve and optimized to obtain the desired function of the cam mechanism. Finally, the cam profile which satisfies the designed follower motion is calculated from the relational equation of cam angle and follower displacement.
The proposed method was used to design the cam profile of VCB (Vacuum Circuit Breaker). The operations of the designed cam and the original cam were compared using ADAMS VCB model which was verified by an experiment using a motion analyzer.
