Kinematic and Static Analyses of Spatial 7R 7-Link Mechanisms with Intersecting Axes

摘要

The formulas for kinematic analyses of the spatial 7R 7-link mechanism are established in the case where three adjacent revolute axes and two adjacent revolute axes intersect a point, respectively. Static analyses of this spatial 7R 7-link mechanism are performed by using the RRSS spatial four link mechanism, centers of whose two spherical pairs coincide with points of intersection of three and two revolute axes, respectively. Conditions for the limit position of the driving link are derived from the denominator of velocity analysis formula and the transmissibility of the forces acting on pairing elements. It is shown analytically and experimentally that the perpendicular distance from the center of the spherical pair of the stationary link, to the plane, which includes the axis of the revolute pair and the center of the spherical pair of the coupler link is useful for evaluating the motion transmis- sibility.