Modeling and investigation on dynamic behaviors of ball screw feed system with bolt looseness

Abstract

In this study, a more comprehensive multi-degree-of-freedom nonlinear dynamic model of ball screw feed system is presented. The relationship between bolt preload and contact force of the interface force is established. A new pedestal force model considering bolt looseness and inclination of contact surface is established. Based on the spatial position between pedestal and foundation, the modeling method of contact force of interface is proposed. The influence of bolt preload and bolt looseness on the dynamics of the feed system are investigated. A series of experiments are conducted to validated the proposed modeling method. The fractal parameters are obtained by the measurement of surface morphology. The results show that the increased preload have impacts on the vibration response and reduce the positioning accuracy of the system in specific frequency. Moreover, the proposed model is compared with traditional method proposed by previous study.