Abstract: An auxiliary torsional damper of the surface-effect type capable of damping torsional spikes which may occur during operational transition through the system's resonance frequency. Preferably, the auxiliary damper will be designed with a decoupling feature such that the damper will only provide auxiliary torsional damping for torsional oscillations which surpass a threshold amplitude. Since the surface-effect damper is deflection dependent, the larger the magnitude of the torsional spike, the larger the damping that will be applied thereto.

Abstract: A flexible dual-rate coupling (20) including an outer member (22), and inner member (24), and a free-floating intermediate member (26). First and second elastomers (28) and (44) provide the dual-rate spring rate characteristics for the coupling (20). First elastomer section (28) is disposed between pocket (50) formed in outer member (22) and outer surface (52) of intermediate member (26) and provides a first spring rate. Second elastomer (44) is disposed between intermediate member (26) and inner member (24) and provides a second spring rate. At a low load, one of the elastomer sections (28) or (44) is delimited (snubbed) to provide dual-rate features for the flexible coupling (20). Both the sections (28) and (44) are preferably pure shear sections which are bonded in the same bonding operation.