Research On Characteristics Extraction Method Of Friction Vibration In The Friction And Wear Process

Wear is one of the main factors to cause the failure of mechanical parts. In the process of mechanical equipment running, excessive wear will cause the failure of mechanical parts or even damage the mechanical equipment, which lead to certain losses in economy. Therefore, it is essential and necessary to monitor the wear status of equipment in the process of operation.It is inevitable to cause friction vibration and friction force in the friction and wear processes of friction pairs. Rich information about wear is carried by the signals of friction vibration and friction force, thus the wear condition of friction pairs can be monitored by the acquisition, processing and analysis of friction vibration and friction force signals. Although at home and abroad, serious efforts have been undertaken to develop the friction vibration and friction force, and the different signal processing methods have been put forward, yet it is still the bottleneck problem how to extract the characteristics from the friction vibration and friction force signals which can reflect the status of friction pair. Therefore, the research on feature extraction from friction vibration signals has a theoretical meaning and significant engineering value.In this paper the friction and wear tests of a piston ring against a cylinder from marine diesel engine were conducted on a friction and wear tester of type MMW-1. The friction vibration and friction force signals were analyzed under different test condition. The feature extraction method on friction vibration and friction force signals was discussed making use of the wavelet packet transform. The mapping relationship between the characteristic parameters of friction vibration and friction force and the wear state of cylinder-piston ring was analyzed.The results show that the parameter P, M and E of frictional vibration and friction force signals can be extracted by using the wavelet packet transform. The parameters of frictional vibration and friction force signals can describe the intensity and complexity of cylinder-piston ring wear. Therefore the wear state of cylinder-piston ring can be the quantitative analysis of the wear state of cylinder-piston ring can be carried out by the parameters of frictional vibration and friction force signals.