Abstract:

ESDU 89028 gives a step-by-step procedure for force-balancing planar single degree of freedom linkages. Balance is achieved by the addition of counterweights so that the resulting centre of mass of the linkage remains stationary throughout the motion cycle. The procedure, each step of which is illustrated by its application to a six bar linkage with a slider, calculates the counterweight masses and their locations. Although the method applies to most linkages composed of rigid links, with revolute joints and sliding joints, a test is included to identify those linkages that cannot be completely force balanced. Advice is given on the optimum shape of the counterweights and on allowable combinations for common linkages. A further fully worked example of a twelve bar linkage driven by a gear pair is included.