Experimental verification of dynamic behavior for multi-link press mechanism with 2D revolute joint considering dry friction clearances and lubricated clearances

The existence of clearance joints seriously affect the kinematic accuracy and service life of precision mechanisms. So as to ensure the kinematic accuracy reliability of mechanism, it is imperative to accurately predict the dynamic behavior of precision mechanism considering clearances. At present, the studies often focus on theoretical analysis and simulation verification of mechanism with clearances, while the studies verified by experiment are relatively few and often focus on simple mechanism. Moreover, most of studies centered on simple mechanism with dry friction clearance, while the studies on complex mechanism with multiple lubricated clearances are less. In this paper, the impact of multiple clearances on dynamic behavior of 2-DOF 9-bar precision press mechanism is analyzed. Firstly, the mathematical models of dry friction clearance and lubricated clearance are established and embedded into the Lagrange dynamic equation, respectively. Then, the impact of clearance values, the material of clearance-shaft and crank driving speeds on dynamic behavior of mechanism are researched. Finally, the simplified experimental platform of 2-DOF 9-bar press mechanism considering 2D revolute joint clearances is established, and the correctness of the theoretical model is proved by experimental verification. This study not only offers theoretical guidance for the layout and life prediction of multi-link press mechanism, but also provides reference for the dynamic behavior analysis and prediction of other mechanisms.