Research On Feature Extraction Of Bearing Fault Based On The Acoustic Emission Parameters

Bearings are important to almost forms of rotating machinery.Its main function is to support the mechanical swivel,to reduce its friction coefficient in the movement process and to ensure its accuracy.Once failure occurs,it will cause great danger.Therefore,the bearings state monitoring and fault feature extraction are the hot topic of current research.In this paper,bearings are taken as the object of study,and the acoustic emission is used as the technical means.The characteristic extraction and parameter analysis were cattied on the four modes of bearings: normal,outer ring fault,rolling failure and inner ring failure bearings.In this paper,it was analyzed in the development history and current situation of acoustic emission on bearings fault diagnosis at home and abroad.And the form of propagation and the wave equation of the acoustic emmission in the medium were studied.A test system for bearings fault feature extraction based on acoustic emission was established.The hardware of this platform consisted of rotating machinery bearing failure simulation platform and acoustic emission acquisition system.And the hardware of this platform consisted of data acquisition module and signal processing module.The characteristic extraction of bearing failure was carried out by acoustic emission parameter analysis.By using the single parameter analysis method such as energy,counts and amplitude and so on,the normal bearings and fault bearings could be comparaed,which could be effecitvely distinguished whether there was a fault;By using the historical varity analysis method of energy and count,the outer ring fault could be extracted;By using distribution analysis method of Hits vs amplitude and Hits vs counts,the rolling and inner ring fault could be distinguished.By using distribution analysis method of Hits energy under different speed,it was found that the energy rose as the speed increased.In the correlation analysis method of the two parameters,it could be distinguished the inner ring fault from other failures by duration time vs amplitude correlation analysis.Using the above acoustic emission parameter analysis method,the comprehensive analysis and feature extraction of bearing failure are realized.