Mechanical Behavior and Design Equations for Elastomer Shear Pad Remote Center Compliances

Commercially available Remote Center Compliances (RCC’s) are made with elastic elements called elastomer shear pads. If these pads are assumed to be linear two-component springs, it is easy to derive equations for the RCC’s composite elastic behavior. These equations can be quite incorrect, however, because the pads are in fact nonlinear six component springs. RCC performance equations incorporating models of real pad behavior are presented here, together with experimental verification. These show that real RCC’s have less stiffness and less compliance center projection than predicted by the linear models. A new design that overcomes these problems is also presented.