Posts Tagged ‘bearing life’

How To Extend The Life Of Pillow Block Bearings

Friday, June 24th, 2016

In many cases, the support bearings of a machine aren’t as secure as they need to be. Because of this, many people opt to use pillow blocks.

These blocks can be used on things like conveyor guides, mining equipment, and fan gear. They can provide any machine with the support it needs.

With that said, these block bearings won’t last forever. If you want them to keep working as they should, you’ll need to provide them with the proper maintenance.

Here are a few of the steps you can take to extend the life of your plummer blocks:

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Use Condition Monitoring To Preserve Bearing Life

Friday, January 8th, 2016

Ball bearings, and other machine bearings for that matter, are incredibly important to the continued life and use of machinery.

Those small metal balls can be the difference between a smoothly working machine, and a machine that breaks down and causes all manner of problems. Due to this, it can be incredibly important to ensure that a machine’s ball bearings are properly maintained.

Unfortunately, it’s not always easy to tell if a bearing has a fault. They’re metal balls, after all. It’s not always easy to tell if there’s a fault in a sphere of metal. Luckily, there’s a process for just that situation. It’s called “condition monitoring”.

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Black Oxidized Bearings for Wind Applications

Friday, October 9th, 2015

Wind turbines are subjected to a wide range of temperatures, wind speeds, and loads over their lifetime. These operating conditions often result in premature bearing damage and failure.

Black oxidized bearings have come forth as a solution to improve the operational reliability of bearings used in wind turbine applications.

The benefit of black oxidation in reducing the risk of premature failures has been proven by extensive field experience.

Gearbox manufacturers and wind turbine OEMs have reported a significant improvement in reduction of bearing failure rates with the use of black oxidized bearings.

The Process

A chemical reaction at the surface layer of the bearing steel is responsible for coating the bearing in black oxide.

Specifically, the bearing is immersed in an alkaline aqueous salt solution at a temperature between 130-150 degrees Celsius. The oxide layer is then produced from the reaction between the iron of the ferrous alloy and the reagents.

Typically, around 15 different immersion steps are followed for the oxidation process. Once finished, the bearing has a dark black surface layer.

The Benefits

Lab investigations, bearing tests, and field experience have shown demonstrated benefits of black oxidized bearings.

In the severe operating conditions of wind turbines, black oxidized bearings cope with both insufficient lubrication and surface damage significantly better than untreated bearings.

Black oxidized bearings reduce bearing surface distress and prolong bearing life, improving the overall safety margin. In use, there is a noticeable reduced friction after running-in.

The black oxide protects against tribochemical attack, reduces the permeation of hydrogen, and increases resistance to moisture damage. Lubricant adhesion is also improved, compared with the use of non-coated surfaces.

You can replace conventional bearings with black oxidized bearings during maintenance routines so that over time, the benefits of black oxidation can be applied to all bearing types used in a wind turbine gearbox system.

For optimal performance, the inner and outer rings, as well as the rolling elements ought to be black oxidized.

Contamination and Bearing Life

Friday, December 13th, 2013

When the environment that a bearing operates in is quite clean, damage is generally caused by the eventual fatigue of the surfaces where rolling contact takes place. But when the bearing system gets contaminated by any particle, it could bring about damage much faster and remarkably shorten bearing life.

Moreover, when debris from a component contaminates the lubricant, the main cause of bearing damage is wear. In the event bearing wear becomes pronounced because of particle contamination of the lubricant, there will be changes that could have a significant impact on the operation of the machine.

Generally speaking, the significant parameters in regards to contaminants that have an influence on the bearing wear are the size, concentration, hardness, and lubricant film thickness. Should there be an increase in all parameters mentioned (except film thickness), an increase in bearing wear will arise, as well.

Always remember that an increase in the viscosity of the lubricant would cut down bearing wear for any contamination level.

Bearings that have a contaminated lubricant will display a higher initial rate of wear as compared to those that are not operating in a contaminated lubricant. But without further contaminant ingress, such wear rate rapidly diminishes since the contamination particles are cut down, size-wise, as they pass through the bearing contact area during normal operation.

Water can bring about bearing etching, and that could shorten bearing fatigue life. Water can sometimes enter micro cracks in the bearing races, brought about by repeated elastic deformation stress cycles. This would then cause corrosion and hydrogen embrittlement in the micro cracks, which lessen the time needed for these cracks to propagate to an unacceptable size spall.

Water base fluids like water glycol as well as invert emulsions could also shorten bearing fatigue life.