Analysis of a four-bar mechanism with a radially compliant clearance joint

Clearance joints in high-speed mechanisms can suffer from contact loss, leading to noise generation and joint deterioration. To predict the onset of contact loss detailed modelling of the joint is required. In this paper a clearance joint is modelled using a combined massless link and spring-damper unit, where the bearing stiffness (spring element) is estimated from a three-dimensional finite element analysis. The combined model is shown to exhibit chaotic behaviour just prior to contact loss and the predictions correlate well with experimental results. The bearing stiffness and damping are shown to have a significant effect on the behaviour of the joint, including the occurrence of chaos and the extent of contact loss regions.