Resonant vibratory riddle - using two-mass system with energy storage springs

摘要

The counterweight, mounted between the sidewalls of the riddle frame is joined to the main mass formed by the frame by rubber springs with non-linear characteristics brought about by the incorporation of air gaps between esp. two spring elements mounted on each side of the wll and on the counterweight. An eccentric drive to the two masses acts on their centre of gravity via an elastic coupling. The drive frequency is 50-80% lower than the self-resonant frequency. The riddle is independent of driveshaft speed and free from damping.