Colloquia

Summary

Optimizing cam geometry to improve energy efficient motion. This study explores optimization possibilities to improve the cam design of the spring-driven Xiria 630 RTC. For this Medium Voltage switchgear the cam is crucial in the mechanical drive of the switching mechanism.

By applying cam-follower motion theory and impact theory, five new cams are developed. Physical tests in the Damstra laboratory with all new cam designs assembled in the Xiria panel show that every cam design is able to complete the required motion. After processing the measurement results in Matlab, the influence of the cam design improvements on the behavior of the mechanism is shown with motion characteristics. Analyzing measurement results shows the increase of effective kinetic energy up to 24.2%.

Next to the cam design optimization, the switching mechanism construction is built in multibody dynamics simulation software MSC Adams. The simulation model parameters are fitted to recreate realistic motion and match measurement results from the physical tests. The validated simulation model is used to predict energy efficient motion of the mechanism for all cam designs. Energy efficient motion is simulated by reducing the energy input in the simulation, achieved by lowering the preload of the driving spring, until the mechanism is not able to complete the full motion.

After evaluating the mechanism new cams are developed, produced, tested and validated. By applying the optimization process and developing new cams, the lab measurements show reduced peak forces in the construction and changes in movement characteristics for elapsed time and velocity. While still satisfying the mechanism requirements, energy efficient motion of the mechanism is predicted with the simulation. With the simulation results is predicted that the mechanism is able to complete the required motion with up to 5.7% less input energy.