Impact Feature Modeling And Quantitative Diagnosis Method Of Defective Rolling Bearing

Rolling bearings are precision mechanical components and play an irreplaceable role in mechanical equipment.However,rolling bearings are extremely susceptible to damage caused by the working environment.Bearings are often assembled inside mechanical equipment,and early bearing defects are often difficult to diagnose in time.At present,bearing defects have become one of the main failure modes of mechanical equipment.The collision between the rolling elements and the local defects will excite obvious vibration and shock,which will cause the bearing to fail quickly.At present,most scholars idealize the local defect and consider it as a flat rectangular form.The three-dimensional size of the local defect and the contact deformation of the rolling element and the raceway will have a great influence on the bearing vibration.The simplified model cannot accurately describe the bearing vibration characteristics excited by the defect morphology characteristics.Therefore,it is urgent to develop the defect characteristics vibration and shock.The study of characteristics provides an effective way to diagnose the size of defects;bearing defects will gradually expand and evolve when impacted by the rolling elements,and the vibration and shock characteristics will change.At present,the relationship between the expansion and evolution characteristics of cylindrical roller bearings and the vibration characteristics of the bearing has not been clarified,so it is urgent It is necessary to carry out research on the relationship between the extension of local defects and the vibration characteristics of cylindrical roller bearings,and provide a reference for the feature identification of cylindrical roller bearing defects;in addition,the roughness of the bearing defect surface will also stimulate the abnormal vibration of the bearing,but the current internal defects Roughness is often ignored by scholars and lacks a modeling method of defect surface roughness.Therefore,the research on modeling method of defect raceway roughness of cylindrical roller bearing is carried out to provide a new reference for the accurate identification of defect characteristics of cylindrical roller bearing.The main research content of the paper:(1)In view of the problems of unclear vibration excitation mechanism of rolling bearing partial defects and difficulty in diagnosis of defect size,a rolling bearing defect impact signal model is proposed to study the influence of bearing defect size,rolling element-raceway contact deformation on the rolling element internal motion law and bearing vibration characteristics The influence law provides theoretical support for the accurate diagnosis of rolling bearing defect size.(2)Aiming at the simple problem of the modeling of local defects in rolling bearing raceways,a dynamic model of rolling bearings that takes into account the expansion of local defects and the influence of the morphological characteristics of local defects is proposed,and the influence of factors such as the various stages of defect expansion and the morphological characteristics of the defects on the vibration acceleration of the outer ring of the bearing is studied.The influence law of domain characteristics.(3)Aiming at the problem of unclear vibration excitation mechanism of surface roughness of local defects,considering the influence of roughness on bearing contact stiffness,a dynamic model of cylindrical roller bearing coupled with raceway roughness and local defects is proposed.The influence of the roughness of the defective raceway on the vibration acceleration of the outer ring of the bearing is studied.Provide a valuable reference for in-depth understanding of the vibration mechanism of defective bearings.(4)In view of the problem that the frequency domain vibration signal cannot accurately diagnose the size of the local defect of rolling bearings,a local defect size diagnosis method coupled in the time domain and frequency domain is proposed.Based on the method of identifying the location of local defects in the frequency domain,the influence of the size of the local defects on the time-domain statistical characteristic values of the vibration acceleration of the bearing outer ring is focused on;based on the Labview embedded programming software,a rolling bearing quality inspection system is established to provide accurate diagnosis of rolling bearing defects Effective way.