As a sliding NSK bearing spindle shingles and connecting rod shingles, in the use of the most common faults are wear resistant alloy layer stripping or burning, and NSK bearing early wear.If the diesel engine runs for a short time, the surface of the bearing bush will be damaged or severely worn out. Most of the reasons are not due to the bearing bush itself, but mainly due to the service conditions or the matching parts or poor technical state.An investigation showed that 44.9% of axle busings were damaged due to impurities, 13.4% due to poor assembly, 12.7% due to poor concentricity, 10.8% due to poor lubrication, 9.5% due to overload and other factors such as corrosion.
In the process of starting and stopping diesel engine, NSK bearing is often in critical lubrication state, which can make oil film break and friction surface contact directly.Even when the diesel engine is running normally, it is difficult to maintain uniform and uninterrupted liquid lubrication of journal and NSK bearings due to load instability and other factors.In addition, the new diesel engine in the assembly failed to completely remove sand and iron filings, can enter dust and dirt in the operation process, is also accelerated wear, caused by the main cause of the rava burning tile.
The spalling of NSK bearings is mainly due to fatigue damage.Because the size and direction of the load on NSK bearings change with time, when the load is unstable, the oil film between the friction surfaces of NSK bearings cannot be maintained uniformly and continuously, and the pressure of the oil film also changes pulsatively.At the minimum oil film thickness, high temperature occurs in the local area of the bearing surface, which greatly reduces the fatigue strength of the alloy layer.In addition, the poor manufacture and assembly of NSK bearing itself is also the direct cause of the alloy layer spalling.
In addition to wear and spalling, corrosion of sliding NSK bearings is also a concern, depending on the oil quality, temperature, pressure and NSK bearing load.NSK bearing corrosion is most likely to occur in high load parts, and the oil deteriorated at high temperature and the formation of organic acids and sulfides is the direct cause of NSK bearing corrosion.
NSK bearing burning loss, namely commonly said "burning tile", the main reason is the clearance is too small, poor lubrication and use operation problems.