1. Handle with care. Never pound directly on a bearing or 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 bearings on a dirty surface; periodically turn over sealed and shielded bearings to prevent grease from settling to one side.
2. Inspect the shaft and housing. Check for size and damage; remove nicks and burrs with emery paper, and wipe clean with a soft cloth. Replace or repair shafts and housings showing obvious signs of wear or damage. A shaft placed in a vise for mounting should be protected from vise jaws with a sheet of soft metal.
3. Avoid overheating. During heat-mounting operations, never bring a flame in direct contact with the bearing and never heat beyond 230° F. Also, immediately hold a heat-mounted bearing in place against the shaft shoulder until it cools and locks in place. Otherwise, the bearing may creep away from the proper position.
4. Use identical replacement bearings. Replacement bearings should be identical to the bearings they replace.
5. Use the right tool for the job. Induction heaters, oil injection kits, and hydraulic nuts are among the specialized tools available for mounting and dismounting bearings over 4 in. O.D. Their use lowers the possibility of damaging bearings and speeds the process.
6. Pay attention to the bearing’s press fit. For bearings with an O.D. less than 4 inches, cold mounting with a press or appropriate mounting tool is acceptable. Pressure should be applied to the ring with the inter- ference fit, or both the inner ring and outer ring simultaneously to avoid Brinelling the raceways. Applying pressure to the ring with the loose fit only will Brinell the raceways and result in noise and potentially premature failure.
7. The contact between the bearing ring and a properly machined and dimensioned bearing seat should not require the use of bonding agents to prevent movement or turning.
8. Don’t wash new bearings. Bearing manufacturers take great care to package and ship bearings that are dirt-free and ready for lubrication. There’s usually no need to wash them or remove the protective slushing compound.
9. Proper lubrication is critical. Bearing manufacturers evaluate several factors before determining the type of lubricant required for specific bearings. Be sure to follow their recommendations. Temperature and contamination conditions will influence the frequency of lubrication changes.
10. Rotate idle bearings. Bearings installed in equipment that is subject to vibration while the shafts are stationary may incur false brinel- ling damage, which also occurs when equipment is not properly protected during shipment. It can appear as bright, polished depressions on the inner and/or outer races, as well as on the rolling elements.
11. Look for danger signs. Keep alert for three sure signs of improper bearing operation: excessive noise and increases in vibration and temperature. Troubleshooting instruments like hand-held vibration pens, digital thermometers, and electronic stethoscopes help spot bearings in poor operating conditions.
12. Find the cause of bearing failures. Bearings are built to last, so frequent failures may point to an installation or lubrication problem.