Abstract
The Stephenson-3 six-link mechanism consists of the planar four-bar linkage and the external dyad. All relationships between the input and output angles are analyzed by solving the algebraic equation of sixth degree. The solutions are mutually contained in different branches or circuits. The branches are the parts of the coupler curves separated by two limit points. A circuit of a linkage is defined as all possible orientations of the links which can be realized without disconnecting any of the joints. In this paper, it is shown that these branches and circuits can be mapped on four number lines which are discriminated by the sign of the determinant of the Jacobian matrix and the sign of the sine of the relative angular displacement between two links of the external dyad. So the motion domains of the driving Link of the Stephenson-3 six-link mechanism are identified.
