Dynamic Behavior Analysis of a Planar Four-bar Linkage with Multiple Clearances Joint

Clearances in the joints are inevitable in practicedue to tolerances, and defects arising from design and manufacturing. In the presence of clearance at a joint, a mechanism gains some additional, uncontrollable degrees of freedom which are the source of error. Moreover, joints undergo wear and backlashes and so cannot be used in precision mechanisms. In this study, the dynamic behaviour of a planar mechanism with revolute joints, in the presence of clearances is investigated. A continuous contact force model, based on the elastic Hertz theory together with a dissipative term, is used to evaluate the contact forces. Moreover, using a new contact model,the dynamic characteristics of planar mechanical system with multiple revolute joints in the presence of clearance are analyzed. Numerical results for four-bar linkage with one, two and three revolute clearance joints are presented and compared.