The cause of the damage of the engine bush
The main shaft of sliding bearing and the connecting rod are the most common faults in the use of the bearing. If after short-term operation of diesel engine, bearing surface which can quickly damage or serious wear and tear, most of the reason is not bearing shell itself, and is mainly due to the bad condition of conditions of use or parts or technology. A survey materials show that bearing the cause of the damage is caused by impurities 44.9%, 13.4% is bad assembly, 12.7% are poor concentricity, 10.8% are poor lubrication, 9.5% is overloaded, the rest is corrosion and other factors.
In the process of starting and stopping the diesel engine, the bearing is often in critical lubrication state, which can make the oil film intermittently and the friction surface contact directly. Even when the diesel engine is operating normally, the axial neck and bearing are difficult to maintain even and uninterrupted fluid lubrication due to the unstable load. In addition, the new diesel engine fails to completely clean the sand and iron in the assembly, but it can get into the dust during the operation, which is also the main reason for the accelerated wear and tear.
The peeling of the bearing is mainly due to fatigue damage. Since the size of the load bearing suffered and direction change with time, when the load is not stable, couldn't keep his uniform bearing friction surface between the continuous oil film, and the oil film pressure is in the land of pulsating flow change. In the thickness of the minimum oil film, high temperature is produced in the local area of the bearing surface, which greatly reduces the fatigue strength of the alloy layer. In addition, the bearing itself produces poor assembly, which is also the direct cause of the peeling of the alloy layer.