Vibration Information Extraction And Failure Analysis Of Rolling Linear Guide Pairs

Rolling linear guide pair is a core instruction component of a high-end CNC machine tool.Abnormal vibration due to its failure can lead to a drop in overall machine tool performance and machining accuracy.As the main forms of guide rail,preload loss,lubrication failure,pitting failure will reduce the accuracy,exacerbate wear and tear,reduce fatigue life.However,the failure information during the operation of the guide rail can be reflected by the vibration signal.Therefore,exploring the vibration characteristics corresponding to different failure modes of guide rail has important engineering application value.This conclusion can be applied to the condition monitoring and failure diagnosis of the guide rail of machine tool.In this paper,the main failure modes and failure mechanisms of the rolling linear guide pair are analyzed.The acquisition techniques,detection methods and analysis methods of the guideway vibration signals are expounded.The characteristics of the research at home and abroad are compared and analyzed.Vibration characteristics extraction of the rolling linear guide pair preload loss,lubrication failure,pitting failure and guide damper oil film loss are focused on research.Through the theoretical analysis,the dynamic model of the roller linear guide pair is established.The relation between preload and natural frequency of the guide rail is obtained and verified by ADAMS simulation.The conclusion is obtained that the loss of preload of roller linear guide pair can be monitored by the deviation of natural frequency.The wavelet packet energy method is used to analyze the vibration signal of the guide rail lubrication failure.The experimental results show that under different lubrication conditions,the vibration signal energy of the rolling linear guide pair shows a large difference at 16 frequency bands and follows the law,which can be used as the eigenvector to distinguish the lubrication conditions.Therefore,it is possible to monitor the state of lubrication by monitoring the vibration of the rolling linear guide pair.The wavelet packet energy spectrum and fuzzy clustering analysis algorithm are proposed to analyze and process the vibration signal under the pitting failure of guide rail.Experimental results show that using wavelet packet decomposition to extract energy parameters of signal as eigenvector and applying fuzzy clustering analysis can well judge the fatigue pitting status of rolling linear guide pair.Finally,the vibration suppression effect of guide damper adopted by high-grade machine tool is studied.The effects of film loss on the vibration damping performance of guide damper are studied emphatically in theory and experiment.The vibration characteristics of the oil film loss of guide damper are extracted by using the amplitude analysis method based on the short-time Fourier transform.The experimental results show that the damper film state can be reflected by monitoring the vibration amplitude of the guide damping system.