SYNTHESIS OF OLDHAM CHAIN BASED SIX-BAR DWELL MECHANISMS FOR THREE-POSE RIGID-BODY GUIDANCE

This paper deals with the kinematic synthesis of Oldham chain based six-bar dwell mechanisms for three-pose rigid-body guidance. In particular, a general algorithm is formulated to firstly synthesize a general Oldham mechanism with inclined or orthogonal slots, in order to reach three finitely separated and assigned positions, and secondly, to give a dwell output link of the whole six-bar mechanism by adding suitable RR or RP dyads. This second step is obtained by applying infinitesimal displacements synthesis methods, which make use of the coupler link centrodes of the Oldham mechanism, along with geometric loci, such as, the inflection and return circles, the circling-points curve and center-points curve, Ball’s point. This dwell can be designed for any Oldham mechanism configuration, which could be coinciding with one of the three assigned poses. The proposed algorithm has been implemented in Matlab and validated by several examples and analysing the corresponding numerical and graphical results.