As the main bearing bush and connecting rod of the sliding bearing, the most common failure in use is the peeling or burning of the wear resistant alloy layer and the early wear of the bearing. If the diesel engine is operated for a short period of time, the surface of the bearing bush is rapidly damaged or severely worn. The reason is mostly not in the bearing bush itself, but mainly due to the use conditions or the poor matching of the parts or the technical state. A survey material showed that 44.9% of the causes of bearing damage were caused by impurities, 13.4% were poorly assembled, 12.7% were too poor concentricity, 10.8% were poorly lubricated, 9.5% were overloaded, and the rest were other factors such as corrosion.
During the starting and stopping of the diesel engine, the bearing is often in a critical lubrication state, which can make the oil film intermittent and the friction surface directly contact. Even when the diesel engine is in normal operation, it is difficult to maintain uniform and uninterrupted liquid lubrication for the journal and the bearing due to factors such as unstable load. In addition, the new diesel engine failed to completely remove the molding sand and iron filings during assembly, and it can enter dust and dirt during operation, which is also the main reason for accelerating wear and causing the lava.
The spalling of the bearing is mainly due to fatigue damage. Since the magnitude and direction of the load applied to the bearing changes with time when the load is unstable, a uniform continuous oil film cannot be maintained between the bearing friction surfaces, and the pressure of the oil film also fluctuates. At the minimum oil film thickness, a high temperature is generated in a local region of the bearing surface, which greatly reduces the fatigue strength of the alloy layer. In addition, the bearing itself is poorly assembled and is the direct cause of the alloy layer peeling off.
In addition, to wearing and spalling, the corrosion of plain bearings is also a significant problem, depending on the quality of the oil, temperature, pressure and bearing load. The high-load parts of the bearings are most prone to corrosion, and the organic acids and sulfides that are formed by the deterioration of the lubricating oil at high temperatures are the direct cause of bearing corrosion.
The burning of the bearing, which is commonly referred to as "burning tile", is mainly due to the small gap, poor lubrication, and problems in operation.
JIASHAN JINGYE IMPORT EXPORT CO., LTD
Add:NO.176 North Tiyu Road,Weitang Street,Jiashan county,Zhejiang Province,China