Roller Bearings Constraints And Problems

As with any type of machinery and its parts, roller bearings are prone to constraints and sometimes failure. Overall the lifetime of roller bearings will outlive the machinery, however if there is a problem with a machine and it is the bearings fault this can be a costly and time consuming to repair.  Due to these failures with roller bearings a lot of work is put into failure analysis where they can learn from the problems the roller bearings are having in a particular machine to aid in rectifying the situation so it doesn't happen again. 

The problem with roller bearings is that they sometimes fail when there is no good reason for the bearing to fail. For example with a stationary load (where it is not rotating and therefore there is no need for the roller bearings to be used) the small vibration creates pressure which squeezes out the lubricant, bearings cannot work without lubricant and therefore when the roller bearings do need to work they fail.

What are some reasons why bearings fail?

There are many reasons why roller bearings and other types of bearings fail, however if you are aware of these reasons you can be careful not to fall into the traps and help prolong the longevity of your bearings and machines.

The load on the bearing has a massive impact on the bearings life. If you load the bearing with excessive amounts this decreases the bearings life by a factor of 8. This is even more severe with roller bearings as the bearing cannot move the weight properly that it was not designed to move. Excessive loading of the bearing causes fatigue, meaning the roller bearing is working harder than it should. It causes the bearing to become damaged and deformed and damages the races as well. Overloading the bearing can also result in pushing out the lubricant between the bearing and the racer which causes metal on metal action which breaks the bearing even faster.

Another reason why a bearing can fail is because of high temperatures. Every bearing has a different maximum temperature it can reach before it harms the bearing, if this maximum temperature is exceeded the bearing's steel will become disfigured. The heat softens the bearing and so the bearing cannot carry the weight it was designed to carry. Often if the cause of failure is temperature related the effect on the bearing is so severe that there is rarely anything left of the bearing to examine which doesn't help in the failure analysis.