Test and Evaluation of Using Thermoelectric Technology to Monitor the Wear of the Journal Bearing of a Diesel Engine

The journal bearing is a key and vulnerable component of a large diesel engine. Once the journal bearing fails to work, it is very difficult repair. On-line monitoring of the wear of the journal bearing has always been one of the research hotspots. Firstly, the monitoring mechanism of the thermoelectric method is discussed in the article. Secondly, the structural characteristics of a 6DK20 marine medium speed diesel engine are analyzed. Thirdly, by using the thermoelectric sensor designed by the research and development team led by the author, the parameters of typical wear state with load conditions are measured. Finally, the directivity of thermoelectric signals is analyzed, and the variation law of the peak value of thermoelectric signals is researched corresponding to the ignition point of time of the diesel engine under typical wear states with load conditions. The results show that the thermoelectric signals reflect the wear and running state of journal bearings and have good directivity and transient feature. Therefore, it has great research value and application value to the evaluation of the wear and failure of journal bearings by thermoelectric technology.