Study on dynamic behavior of planar multibody system with multiple lubrication clearance joints

With the wide application of multi-link mechanism, it is necessary to establish an accurate and reliable dynamic model to analyze dynamic response of multi-link mechanism. In the practical application of multi-link mechanism, lubricating oil has been widely used in kinematic pair to reduce influence of clearance on accuracy and stability of mechanism. Research on dynamic response of multi-link mechanism with clearance mainly focuses on effect of dry friction clearance, and effect of lubrication clearance on mechanism mainly focuses on simple mechanism. There are few studies on dynamic response and nonlinear characteristics of multi-link complex mechanisms with multiple lubrication clearance joints. It is rare to study multiple DOFs complex mechanism testbed with multiple lubrication clearances. Lubrication force of lubrication clearance is established by modified Pinkus-Sternlicht model. A transition force model considering both lubrication and dry friction is established. Dynamic model of 2 DOFs 9-bar mechanism considering multiple lubrication clearances is established by Lagrange multiplier method. Effects of dry friction clearance and lubrication clearance on dynamic behavior of mechanism are compared and analyzed. Effects of dynamic viscosity of lubricating oil, crank speed and clearance value on dynamic response of mechanism with lubrication clearances are analyzed. Test platform with lubrication clearance is built, influences of clearance value and driving speed on test platform of mechanism considering lubrication clearance are studied, and correctness of theoretical model is verified by experimental data.