Trouble Shooting (Bearing Doctor)
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Load / Contact Patterns
Typical running traces
As bearings rotate, the raceways of the inner ring and outer ring make contact with the rolling elements. This results in a Wear path on both the rolling elements and raceways. Running traces are useful, because they indicate the load conditions. They should be carefully observed when bearings are disassembled.
If the running traces are clearly defined, it is possible to determine whether the bearing is carrying a radial load, axial load or moment load. Additionally running traces can help determine the accuracy of bearing roundness, confirm whether unexpected loads or large mounting errors occurred, and shed light on probable causes of bearing damage.
Damage Types & Causes
In general, if rolling bearings are used correctly, they will survive to their predicted fatigue life. Bearings, however, often fail prematurely due to avoidable mistakes. The causes of, this premature failure include improper mounting, mishandling, poor lubrication, entry of foreign matter or abnormal heat generation.
For example, one cause of premature failure is rib Scoring which is due to insufficient lubrication, use of improper lubricant, faulty lubrication system, entry of foreign matter, bearing mounting error, excessive deflection of the shaft or some combination of these. If all conditions are known for the times both before and after the failure, including the application, the operating conditions, and environment, then a countermeasure can be determined by studying the nature of the failure and its probable causes. A successful countermeasure will reduce similar failures or prevent them from happening again.
Examples of bearing damage and countermeasures are presented in the following sections. Please consult these sections when trying to determine the cause of bearing damage.
Help Me Find a Damage Type
Where is the damage located in the bearing (select one)?
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