Design of an optimal shock-damping isolator with application to casters

Design of an optimal shock-damping isolator is presented in this paper with specific application to casters. The design is first formulated as an optimization problem to minimize the peak acceleration of a load while keeping the maximal deflection of the isolator within a specified physical limit. The resulting solution is a constant force isolator. However, it is difficult to realize a constant force isolator with conventional mechanisms using linear springs and dampers. To implement such an isolator physically, a novel mechanism employing multiple linear springs has been developed. The structure and the parameters of the springs have been chosen by optimization techniques, and the resulting mechanism has been embodied in a prototype caster design. This paper presents the concept, design procedure, simulation and experimental evaluation results of a prototype optimal shock-damping caster in detail. The peak acceleration of this new design is only 65% of the existing caster. From a manufacturing point of view, this newly designed caster is not much more complex than existing ones.