Dynamic modeling and friction force analysis of ball screw feed system with eccentric load and high acceleration

Dynamic performance of ball screw feed system is negatively affected by the vibration and friction, which are mainly related to the contact characteristics of rolling kinematic joints. In this study, starting from clarifying the friction mechanism, a coupling dynamic model of a feed system was developed. The excitation forces and moments are analyzed to investigate the contribution to the vibration characteristics. Based on the coulomb and viscous friction theories, the viscous friction, sliding friction and elastic hysteresis friction are formulated. According to the benefits of the comprehensive model, the vibration responses and friction forces can be obtained by solving the dynamic equations, which avoids the iterative formula of contact loads and angles. Vibration testing experiment is performed to prove the validity. In particular, the effects of excitation force, feeding acceleration and eccentric distance on the vibration and friction characteristics are investigated. Furthermore, the model can supply some theoretical principles to suppress vibration and friction. The study also helps to improve the performance of a ball screw feed system.