Contact fatigue failuresystem
Failure of bearing working surface under the action of alternatingstress. Contact fatigue spalling occurs on the working surface of the bearing,often accompanied by fatigue cracks. It first occurs at the point below thecontact surface where the maximum alternating shear stress is generated, andthen extends to the surface to form different spalling shapes, such as pittingor pitting spalling, and spalling into small pieces called shallow spalling. Asthe flaking surface expands gradually, it tends to expand to the deep layer,forming deep spalling. Deep spalling is the source of contact fatigue failure.
Wear failure system
Refers to the failure caused by the constant wear of metal on theworking surface caused by the relative sliding friction between surfaces.Sustained wear will cause gradual damage to bearing parts and eventually leadto loss of bearing size accuracy and other related problems. Wear may affectthe change of shape, increase of clearance and change of working surfacetopography, may affect lubricant or contaminate it to a certain extent andcause complete loss of lubrication function, thus causing loss of bearingrotation accuracy and even failure of normal operation. Wear failure is one ofthe most common failure modes of bearings.
Abrasive wear system
Refers to the wear between the working surfaces of the bearing,which is caused by the rubbing of foreign hard particles or hard foreignobjects or metal surfaces and the relative movement of contact surfaces. Hardparticles or foreign matter may come from inside the main engine or from otheradjacent parts of the host system sent into the bearing by a lubricatingmedium. Knowledge of bearing accuracy error. Adhesive wear refers to thebecause of the friction surface microscopic bumps or foreign bodies make thefriction surface is uneven, serious deterioration, the condition of lubricationfor local friction heat production, easy to cause local deformation andfriction surface friction welded phenomenon, serious when the surface of themetal may be the partial melting, contact surface forces from the localfriction welding points on the matrix will be torn and increase the plasticdeformation. This adhesive - tearing - adhesive circular process constitutesadhesive wear. In general, slight adhesive wear is called abrasion, and severeadhesive wear is called bite.
The main reason is defect and overload. When the applied loadexceeds the material strength limit, the part fracture is called overloadfracture. The main reason of overload is the sudden failure of main engine orimproper installation. Defects such as micro-cracks, shrinkage holes, airbubbles, large foreign debris, overheated tissues and local burns of bearingparts may also cause fracture at the defects when impact overload or severevibration occurs. It should be pointed out that in the process of bearingmanufacturing, the incoming inspection of raw materials, the quality control offorging and heat treatment, and the control of processing process can becorrectly analyzed through instruments whether the above defects exist or not,and the control must be strengthened in the future. But generally speaking, themost common bearing failure is overload failure.
Bearing in the work, due to the influence of external or internal factors,the original matching clearance changes, the accuracy decreases, and evencauses "bite dead" is called "clearance change failure. Externalfactors such as excessive interference, improper installation, expansion causedby temperature rise, instantaneous overload, etc.
1. If get good lubrication, and cut off the right moisture anddebris, said oil seal should not wear. However, when open the bearing box, bestcheck bearing and periodically check the oil seal. Check of the condition ofthe near the bearing oil seal, to ensure that they are enough to prevent hotcorrosion along the axis of the liquid or gas into liquid or bearing, oil sealif already wear should be replaced as soon as possible.
2. High temperatures often indicate that the bearing is already inan abnormal condition. High temperatures are also harmful to the lubricantsinside the bearing. Sometimes the overheating of the bearing can be attributedto the lubricant of the bearing.
Causes of high temperature bearings include: insufficient orexcessive lubrication, lubricant containing magazines, excessive load, bearingdamage, insufficient clearance, and high temperature friction from oil seals.
3. Check the status of the machine in operation and monitor it, soas not to cause equipment shutdown.