Proper lubrication is critical to bearing and machine performance. Timken application and environment-specific grease lubricants have been developed from our knowledge of tribology, anti-friction bearings and how these two properties affect overall system performance.
For continuous casters, the most widely used lubrication method is the centralized grease distribution system. Several separate systems are used serving a discrete caster section. These systems pump a relatively small amount of grease at frequent intervals to the bearing. The grease quantity is typically less than 5cc (0.15 oz.), but the frequency is typically six to 10 times per hour. This frequent cycle keeps the bearing full with fresh grease while also purging old grease and contaminants.
An alternative is the air-oil system, which uses compressed air to drive a film of oil through distribution pipes to the bearings. These systems operate continuously to keep fresh lubricant flowing while purging the bearing. The air-oil systems can operate with significantly reduced lubricant consumption. Consult with a Timken engineer for air-oil application.
The bearing positions associated with the support of the slab combine high loads and elevated temperatures with low rotational speed. This presents difficulties in creating a lubricant film between the bearing’s rollers and raceways. A lubricant viscosity of more than 3000cSt/15000SUS would be required, but distribution systems are limited to a maximum of about 600cSt/2000SUS. High viscosity base oil greases in the segment positions must also be selected to resist corrosion and aid in sealing as a result of continuous exposure to secondary cooling water spray and hard debris contamination.
Contact your Timken representative for more information on proper lubrication practices for your application.