Designing four-bar linkages for path generation with worst case joint clearances

The calculation of mechanism parameters required to achieve or approximate a set of prescribed rigid-body path points is determined by the use of Four-bar path generation. This work will discuss the use of path generation while considering the position tolerance resulting from joint running clearance. Not only will this work discuss the use of path generation of four-bar mechanism in its familiar form, it will include position tolerance as a result of joint running clearance. The standards of American National Standard Institute (ANSI) will be applied in this study. This paper will implement the joint tolerances into the conventional planar four-bar path generation model displacement matrix as a design constraint. This synthesis will produce a planar four-bar mechanism with moving pivots and length tolerance limits from which any mechanism can be created to travel throughout the prescribed path for a coupler point with its specified tolerance. An example to demonstrate the synthesis of a four-bar mechanism with joint tolerances is included.