Study On Bearing Wear Monitoring System For Two Stroke Low-Speed Diesel Engines

With the rapid development of global economic integration, Ocean Transport is increasing playing a important role in the field of International Logistics. Therefore, the smooth and safety running of the diesel engine must be ensured. Among all the parts of the diesel engine, crankshaft and its bearings are the most important components. Recently, more and more engine makers, shipyards and ship owners begin to realize the limitations of Oil Mist Detector: it’s reponse is slowly so that the bearings usually have been damaged before it releases an alarm. So people would be like to online monitor the condition of bearings.In this thesis, the current running situation of the most popular two-strike diesel engine, a methodical analysis of internal factors and external factors that lead to engine bearing wear faults are summarized and categorized. In order to improving the security of bearings, one kind of bearing wear monitoring system is introduced in this thesis. The method is based on the fact that any change in bearing wall thickness will result in corresponding change of Bottom Dead Centre(BDC). The system measures and compares the BDC level to monitor the condition of main bearings, crankpin bearings and crosshead bearings.The thesis worked out an logical algorithm and confirmed its feasibility and practicality by analyzing the result of prototype testing, the data of how BDC level chaing on different working condition and the performance of on-board test. The system made it true that online monitor the condition of bearings and its resolution reached 0.01 mm.Moreover, the system could release an emergency response when the wearing reach the alarm level or when some abnormal wearing come up. If necessary, the system should can communicate with the Alarm Monitor System and give a slowdown request to it.