Stability Analysis and Optimal Design of High-Speed and High-Load Driving Mechanism With Joint Clearance Based on Multi-Body Dynamics

Abstract

High-speed and high-load driving mechanism with joint clearance presents strong nonlinear features which affects the dynamic characteristics of the mechanism. A single-degree-of-freedom multi-body model, including nine connecting links, three translation joints and ten revolute joints with clearance, is built with the continuous contact method based on research of dynamics theory about joint clearance. Furthermore, normal forces are calculated with a nonlinear continuous contact force model and tangential forces are calculated with the modified Coulomb friction model to simulate process of contact and collision. When the model is solved according to real operating condition, the results are compared with that of the model with ideal joints, finding that revolute joint clearance will create effects on velocity and especially great effects on acceleration of the driving mechanism. Moreover, different amounts and different sizes of the clearance are considered to research the influence on dynamic characteristics of the driving mechanism. Meanwhile, methods of optimal design are explored according to the parametric analysis computing results. Simulation methods and findings can act as guidance for further study of optimal design for high-speed and high-load driving mechanisms to reduce the negative effects of joint clearance.