Reducing the undesirable effects of the planar conjugate cam linkage mechanism with multiple clearances

The dynamic behavior of the mechanism is subject to the influence of the clearance in the joints. Existing methods for improving the mechanism's performance usually focus on one type of clearance joint, ignoring the interaction among multiple different types of clearance joints. To address this gap, an optimization method is proposed to lower adverse impact forces and vibrations in planar conjugate cam linkage mechanisms with cam and revolute clearance joints. The contact force model of the clearance joint is formulated using the Flores contact force model and the modified Coulomb friction model. Based on these models and Lagrange's equation of the first kind, the dynamic equations of the mechanism describe its behavior during operation. The optimization method is aimed at minimizing the peak of the mechanism's maximum absolute acceleration by employing the whale optimization algorithm (WOA) to optimize the length of the linkages and the initial angles between them. Additionally, the slider stroke serves as a constraint function. Finally, the effectiveness of the approach is validated using an example of a planar conjugate cam linkage mechanism. Simulation results show a reduction of 65.8% in acceleration peaks and 64.2% in the clearance revolute joint maximum contact force.