Modeling of ball screw fault passing frequencies and nut vibration response affected by wear
摘要
Effect of components wear on dynamic performance of machine tool ball screw drives is modeled using a time-domain simulation model of feed drive for model-based monitoring. The displacement of defect and its position with respect to vicinity components are used to model the frequencies that appear due to wear. The magnitude of forces is modeled using a three-dimensional engagement model. The wear model is combined with a hybrid nut position-dependent feed dive finite element model with coupled screw-nut deformations at the screw-nut interface. The acceleration FFTs at the nut, which is measurable by acceleration sensor mounted on the nut, are predicted for defects on different components, which contain fault frequencies. The experimentally validated model accurately predicts the fault frequencies and vibration spectrums affected by wear and can be used for wear identification of ball screw drives.