Locomotive rolling bearing fault generation and diagnosis method

As the main components of the locomotive, especially the traction motor and the axle box bearing, its function plays an important role in the safe transportation. When the locomotive runs on the line, once the bearing fails, the whole train will not run, blocking the transportation line. Especially when the passenger train fails, the negative impact is even greater. At the same time, once the locomotive bearing fails, it is very difficult to repair the locomotive. Therefore, it is very important to prevent and reduce the occurrence of locomotive bearing faults. Whether the bearing with hidden troubles can be detected before the bearing is loaded, and the qualified bearing accessories are guaranteed to be the focus of this article {TodayHot}.

2 bearing failure

Serious damage to the bearing is often not caused by a single cause, but in a combination of several aspects, a vicious cycle occurs under severe operating conditions, resulting in severe bearing burnout, so after an accident, it is often difficult to judge What causes it, it also brings certain difficulties to us to develop relevant measures. For the convenience of discussion, we first analyze the causes of bearing failures from several aspects.

2.1 Abnormal wear of the bearing

2.1.1 When the bearing is used for a period of time, the inner ring of the bearing, the rolling element, the cage, the outer ring, the raceway, etc. produce certain defects and scars, resulting in poor lubrication of the bearing, causing heat generation of the bearing, long-term heating, Lead to: (1) dilution of bearing lubricants. (2) Accelerate the fatigue of the material and reduce the hardness. Due to the above reasons, a vicious cycle is further formed, and the overheating is accelerated to burn the bearing. Severe bearing inner ring displacement, rolling element out of round, collision heat, and finally welded together. Therefore, when running online, if {HotTag} finds that the bearing is seriously hot and smokes, do not stop, but keep running to the front station, because the overheated bearing is in a molten state at this moment, once it stops cooling, it can no longer walk, blocking the positive line. .

2.1.2 It is very important for the oil supply maintenance of locomotive bearings, especially for the proper amount of oil to ensure that the bearing has good lubrication. It is easy to cause bearing failure due to lack of oil and excessive oiling. Poor lubrication and heat. If it is added too much, it will easily cause agitation and overheating. Therefore, it is necessary to supply oil properly during maintenance. At the same time, the lubricating grease of the bearing is also very important. Once other impurities and moisture are dropped into the grease, it will affect the normal swimming. Gap and build the necessary oil film.

2.1.3 The bearing is used for too long, which exceeds the service life of the bearing and is prone to fatigue of the material. The strong impact of the material causes the material to deform, causing the roller and the raceway surface to peel off and crush, resulting in poor lubrication. And the vibration is increased.

2.2 Installation impact on bearings

2.2.1 Bearing inner ring and shaft fit clearance interference does not match, it is easy to cause bearing failure, large interference, it is easy to cause the bearing inner ring to crack due to excessive tensile stress, the interference is too small, also It is easy to cause the inner ring of the bearing to "relax".

2.2.2 Bearing assembly with improper clearance, it is easy to cause bearing failure, small clearance is easy to cause friction between the roller and the raceway. As the temperature rises, the bearing inner ring, rolling element, cage, outer ring The temperature of the end caps is not the same, there is a temperature difference between them, so the amount of expansion is also slightly different, which causes a further reduction of the matching clearance, and the heat generation of the bearing is added. If the gap is too large, the vibration of the roller is increased, which aggravates the impact of the roller and the raceway. At the same time, the internal load is unevenly distributed, the load roller is reduced, and the central roller load is excessive.

2.2.3 When the bearing is assembled, the bearing is not impacted by the copper hammer, which causes the cage to be deformed. The inner and outer rings of the traction motor bearing are not installed correctly or other reasons cause the axial traverse amount to disappear, causing the bearing shaft to collapse.