2. Roller Bearings— Roller Bearings come in a variety of types. Although the load capacities vary,they will not be exceeded if the guidelines of the load capacities in catalogs or engineering manuals are followed. From an application standpoint, two important items about these bearings should be considered:
A. Seals—Roller bearings generally have either no seals, a labyrinth seal, or more effective teflon or felt seals. For most warehouse applications, a no seal or labyrinth seal bearing is suitable. For problem environments, a sealed bearing should be considered.
Bearings without seals have no protection from foreign matter. The labyrinth seal has an offset or a fixed rigid barrier which inhibits but does not restrict foreign matter.
The Teflon seal is most effective. Its contact with the shaft will keep out most foreign matter.
B. Lubricant—Most rollers are greased or oiled to withstand temperatures of about -40°F to 250°F. Sometimes a special lubricant is needed to meet environmental requirements.