1. Contact fatigue failure
Contact fatigue failure refers to the failure of bearing working surface caused by alternating stress. Contact fatigue spalling For Regular occurs on the working surface of the bearing and is often accompanied by fatigue cracks.
It first occurs from the large alternating shear stress below the contact surface, and then extends to the surface to form different For Regular spalling shapes, such as pitting or pitting spalling, which is called shallow spalling.
Due to the gradual expansion of the spalling surface, it often expands to the deep layer, forming deep spalling. Deep spalling is the fatigue source of contact fatigue failure.
2. Wear failure
Wear failure refers to the failure caused by the continuous wear of the metal on the working surface caused by the relative sliding friction between the surfaces. Continuous wear will cause gradual damage to bearing parts, and eventually lead to the loss of bearing dimensional accuracy and other related problems.
Wear may affect the change of shape, the increase of fit clearance and the change of working surface morphology, may affect the lubricant or make it polluted to a certain extent, resulting in the For Regular complete loss of lubrication function, so that the bearing loses the rotation accuracy and even cannot operate normally.
Wear failure is one of the common failure modes of various bearings. According to the wear form, it can be divided into common abrasive wear and adhesive wear.
Abrasive wear refers to the wear caused by the extrusion of foreign hard particles or hard foreign matters or wear debris on the For Regular metal surface between the working surfaces of SKF and the relative movement of the contact surface, which often causes furrow like scratch on the working surface of bearing.
Hard particles or foreign matters may come from the inside of the host machine or from other For Regular adjacent parts of the host system, and are sent into the bearing by the lubricating medium. Adhesive wear refers to the uneven stress on the friction surface due to the micro bulge or foreign matter on the friction surface.
When the lubrication conditions are seriously deteriorated, the local deformation and friction micro welding of the friction For Regular surface are easy to be caused due to the heat generated by local friction. In serious cases, the surface metal may be locally melted,
and the force on the contact surface will tear the local friction welding point from the substrate and increase the plastic deformation. This cycle of adhesion tear adhesion constitutes adhesive wear. Generally speaking, slight adhesive wear is called scratch and severe adhesive wear is called bite.
The main causes of SKF fracture failure are defect and overload. When the external load exceeds the material strength limit and causes the part to break, it is For Regular called overload fracture. The main cause of overload is the sudden failure or improper installation of the host.
Defects such as microcracks, shrinkage cavities, bubbles, large foreign objects, overheated tissue and local burns of bearing parts For Regular will also cause fracture at the defect during impact overload or violent vibration, which is called defect fracture.
It should be pointed out that in the manufacturing process of bearings, the presence of the above defects can be correctly analyzed by instruments in the factory re inspection of raw materials,
quality control of forging and heat treatment, and processing process control, and the control must be strengthened in the future. But For Regular generally speaking, most of the bearing fracture failures are overload failures.
4. Clearance change failure
During the operation of SKF, due to the influence of external or internal factors, the original fit clearance is changed, the accuracy is reduced, and even “bite” is called clearance change failure. External factors such as excessive interference, improper installation,
expansion caused by temperature rise, instantaneous overload, etc., and internal factors such as residual austenite and residual stress in an unstable state are the main reasons for the change and failure of clearance.
Check whether the SKF Bearing is in good condition and whether the SKF Bearing can be replaced regularly when the SKF Bearing is disassembled and operated again.
Also carefully investigate and record the appearance of the removed SKF bearings. In order to find out and investigate the remaining amount of lubricant, SKF bearings should be well cleaned after sampling.
Secondly, check the raceway surface, rolling surface and mating surface of SKF Bearing and the wear state of cage for damage and abnormalities, especially observe the running track of raceway surface.
Judge whether the bearing can be used again after considering the degree of bearing damage, machine performance, importance, operating conditions, inspection cycle, etc.
According to the inspection results, if the SKF Bearing is found to be damaged or abnormal, please find out the causes and formulate countermeasures according to the phenomenon of bearing damage.
In addition, according to the inspection results, if there are the following defects, the SKF Bearing can no longer be used and needs to be replaced with a new bearing.
1. The raceway surface and rolling element are rusty and scarred.
2. There are significant indentation and indentation on the rolling surface and rolling element.
3. There is creep on the inner diameter surface of the inner ring or the outer diameter of the outer ring.
4. Overheating and discoloration.
4. The sealing ring and dust cover of grease sealed bearing are seriously damaged.
5. Any one of the inner and outer rings, rolling elements and cage has cracks and fragments.
6. Any one of the inner and outer rings and rolling elements has peeling.
7. The raceway surface, retaining edge and rolling element are significantly jammed.
8. The cage is seriously worn or the rivet is loose.