What are the the common causes of bearing damage?

troubles in the lube oil system is the most common problem found.
the baring will have lack of oil pressure or flow to keep the rotor safely without rubbing.

What are the common causes of bearing damage?   Insufficient lubrication during maintenance results in premature wear out of bearing on pump shaft.
Distortion failure occurs when geometrical changes prevent a component from functioning properly such as a swollen polymer bearing in a pump Microbiologically influenced corrosion in a cooling water piping system, Whether or not wear damage constitutes failure of a component depends on the performance criteria of the component, such as in a failed diesel engine main bearing The load-carrying attributes of a material can be altered substantially through different types of processing.
Any processes that alter mechanical properties, such as heat treatment, rolling, welding, and grinding, can affect the load-bearing characteristics by enhancing or reducing the resistance to specific loading types however, as wear takes place in the thrust bearing, the clearance between the nut plus washer at the top of the kingpin and the top of the stub axle yoke decreases to the point where the load path changes When vehicles being shipped are tied down to prevent movement, the rolling elements of axle bearings are held in a fixed position under load and may experience impact loads high enough to cause damage from brinelling.
This type of issue should be addressed no later than the embodiment design phase of the design process in order to avoid problems during delivery and afterwards.
It turned out that a bearing failure in a large industrial dynamometer was the result of the withholding of design information from a new employee by one who felt that his position had been usurped.
What started as a routine bearing and material failure analysis ended up as a seminar for the company on project management? Some Abstracts By: Osama M Abdalla   Member Royal Aeronautical Society - London, License ECA             "ASM Metals Hand Book Volume11 - Failure Analysis and Prevention"