Research On Extraction Methods And Characteristics About Rubbing Vibration Signal Of Sliding Bearing Under Different Frictional Conditions

Rub-impact is a dynamic phenomenon caused by contact and friction between the moving and static parts.The vibratory response is very complex and contains many dynamic characteristics.Therefore,the study of rubbing vibration can provide a new idea for monitoring and recognizing the operating status of mechanical equipments.It has great significance for energy conservation,emission reduction,rational operation and safety production.In order to monitor the operating states and fault forms of the sliding bearing by the rubbing vibration,the test is carried out on the RCYZC-B intelligent test bench and collects vibration signals under different speeds,so as to study the form,separation and dynamic characteristics of the rubbing vibration.Then complete the characterization of collision and frictional vibration signal.The main research contents are as follows:1.The vibration signals in operation test of the sliding bearing under different speeds are collected and analyzed.Results show that:the vibration signals under different speeds is complex and has many components,the spectrum is composed of large-amplitude spectrum and small-amplitude continuous spectrum.2.Through the theory of harmonic wavelet packet transform,the original vibration signals are decomposed into 10 layers,with a total of 1024 frequency bands,then separate the dominant frequency signal and the sideband signal,and the separation signal is analyzed with the rubbing mechanism.Results show that:the dominant frequency signal is collision vibration signal,its frequency value has the characteristic of periodic evolution and increases with the speed;the sideband signal is frictional vibration signal,the variation about characteristic value of the signal is consistent with the change law of friction coefficient and has chaotic characteristics.3.The evolution process of attractor structures about the collision and frictional vibration signals is analyzed by the phase space reconstruction and the attractor theory.Results show that:the attractor of collision vibration signal is the limit loop attractor,its structure increases first and then decreases with the change of frictional states,which is contrary to the variation law of minimum oil film on the sliding bearing;the attractor of frictional vibration signal is chaotic attractor,its structure decreases gradually with the change of frictional states,which is consistent with the variation law of friction coefficient on the sliding bearing.