Theoretical and experimental studies on effect of impact load on dynamic characteristics of multi-link press mechanisms with clearances

In the multi-link press mechanism, clearances of kinematic pairs are inevitable. Additionally, the mechanism is unavoidably subjected to impact loads during operation. These impact loads degrade the dynamic characteristics of press mechanisms, significantly impacting its accuracy and stability. Currently, the studies on the dynamic characteristics of mechanisms are primarily focused on the influence of the clearances on them. The experimental and theoretical research on the dynamics of mechanisms considering impact loads is extremely rare. Therefore, this paper presents an investigation on the influence of impact loads on the dynamic characteristics of multi-link press mechanisms with clearances. Taking a 2-DOF seven-bar press mechanism as an example, the contact force model between the shaft and bearing in the kinematic pairs is established by the Lankarani-Nikravesh model and modified Coulomb model. Following this, a dynamic model of the seven-bar mechanism with clearances under impact loads is established by using the Lagrange multiplier method. And then, the dynamic equation of the mechanism is solved by Runge-Kutta numerical method, the effect of impact loads on the dynamic response of the mechanism is analyzed. Finally, an experimental prototype is built, and experimental research is conducted to verify the effectiveness of the model and the correctness of theoretical analysis. This study can provide a basis for accurately predicting the dynamic characteristics of mechanisms with clearances considering impact loads.

Automated summary

This study investigates the impact of impact loads on the dynamic characteristics of multi-link press mechanisms with clearances. By establishing mathematical models and conducting experimental verification, it provides a basis for accurately predicting the dynamic characteristics of mechanisms with clearances considering impact loads.