The performance of ball bearings can be critically affected by minute particles. Particles as small as 0.005mm can cause problems. To prevent such problems, we use a class 1,000 clean room throughout our bearing assembly operation. “Keeping bearings clean” is the most important rule of bearing use. Avoid exposing bearings to any environment where particles may be present. Once inside a bearing, such particles can cause raceway scratches, abrasion and shortened life. They can also generate acoustic noise and vibration.
We use shields or seals to keep particles out. But there is still a gap between the shield and inner ring of shields and non-contact seals. This gap may permit particle entry. So it is important to observe the following procedures carefully.
1. Keep your bearing handling area as clean as possible.
2. Do not remove the bearings from their packaging until just before use. If you move the bearings to a container, be sure the container is clean. Its lid should be kept closed and it should be cleaned every day to prevent particle accumulation.
3. Never use a bearing that has been dropped. It may be brinelled (race track dented). In use, a brinelled bearing will generate a high level of acoustic noise.
4. Before applying adhesive to a bearing, use a cloth dampened with an alcohol agent to clean oily materials such as anti-corrosion oil from the inner and outer rings. Do not saturate the cloth excessively with the cleaning agent. The liquid agent itself could leak into the bearing, carrying particles with it. Always wring out the cloth before use.
5. When applying a lubricant to the outer circumference of a bearing, take care to make sure the lubricant is not contaminated.
6. Do not handle bearings in a place where they could be directly exposed to outside air. A seasonal wind might bring in dust and other particles.