Optimal design procedure is performed to eliminate contact loss at a clearance joint by using Haines' design chart which predicts quantitatively whether contact loss is or not. The objective function to be minimized is the mass moment of inertia of the additional mass attached to the coupler. In addition, to reduce the fluctuations with high frequency of the contact force, it is proposed to give some margin to the constraint condition of the optimal design.
Numerical examples for an offset slider-crank mechanism and a 4-bar mechanism are considered, and the results of these examples are compared with the other's work in which the objective function is based on Earles & Wu Criterion.
Earles & Wu Criterion cannot predict the contact loss accurately, therefore any design based on their criterion may not get the intended result.
The design method in this research can predict contact loss quantitatively and Minimizing the mass moment of inertia of additional mass without invoking contact loss seems to be a good objective for these kind of mechanisms and Adjusting the margin to the constraint condition also provides some design flexibilities.
In the dynamic simulation of the clearance mechanisms, the clearance joint is modelled using Hertzian contact theory.
