Ten Tips for Trouble Free Bearing Operation

The SKF Bearing Maintenance Institute recommends the following bearing maintenance tips to maximize bearing performance:

1. Handle with care

Always handle bearings as the precision components they are. Cracks and nicks too fine for the human eye will lead to poor bearing performance and eventual failure. Avoid bringing sharp objects into contact with the bearing and never pound directly on a bearing or a ring. If a bearing is dropped, it is best not to install it. Store bearings horizontally in a dry place in their original unopened package and never place bearing on a dirty surface. Avoid leaving a bearing exposed to air-borne contaminants. A speck of dirt in a raceway can lead to premature failure.

2. Inspect shaft and housing

Always inspect the shaft and housing for size and physical condition before mounting a bearing. Check for damage, remove nicks and burrs with emery paper, and wipe clean with a soft cloth. Replace or repair shafts and housings showing obvious signs or wear or damage. A shaft placed in a vise for mounting should be protected from vise jaws with sheets of brass, copper or other soft metal.

3. Avoid overheating

During heat-mounting operations, never bring a flame in direct contact with the bearing and never heat beyond 250 degrees F. Also, immediately hold a heated bearing in place against the shaft until it cools and locks in place. Otherwise, the bearing may creep away from the proper position.

4. Use the right tool

Induction heaters, oil injection kits, and hydraulic nuts are among the specialized tools available for mounting and dismounting. Their use lowers the possibility of damaging bearings and speeds the mounting/dismounting process.

5. Same replacement bearing

Replacement bearings should be identical to the bearings they replace. Bearing identification usually appears on the bearing and/or the box in which it was originally packaged. Contact the manufacturer for part number verification if there is any uncertainty about the replacement.

6. Watch bearing press fit

In bearing press mounting operations, pressure should be applied only to the ring with the press fit, which is usually the ring that rotates after the bearing is installed. Pressure to the ring without the press fit will damage the raceways.

7. Don't wash new bearings

Bearing manufacturers take great care to package and ship bearings that are dirt-free and ready for specific bearing requirements. There's usually no need to wash them or remove the protective slushing compound. Exceptions arise when the operating lubricant to be used is a polyurea grease or synthetic. use of these lubricants may require removal of the slushing compound.

8. Proper lube is critical

Bearing manufacturers evaluate several factors before determining the type of lubricant required for specific bearing requirements. Be sure to follow their recommendations. Check lubrication levels frequently and change the lubricant at least once a year. Temperature and contamination conditions will influence the frequency of lubrication changes.

9. Rotate idle bearing

Bearings installed in equipment that is subject to vibration while the shafts are stationary may incur false brinelling damage. False brinelling also occurs when equipment not properly protected to prevent movement of bearings during shipment. It can also appear as bright polished depressions on the inner and/or outer races, as well as on the rolling elements. Guard against this by periodically rotating the bearings or briefly operating the equipment in which they are installed.

10. Look for danger signs

Keep alert for these sure signs of improper bearing operation: excessive noise and increase in vibration and/or temperature. Bearings exhibiting any of these symptoms should be checked frequently for deterioration and possible removal. Troubleshooting instruments like hand held vibration pens, digital thermometers, and electronic stethoscopes help spot bearing in poor operating condition.