Processing a bearing with CSL is a multi-stage operation. Each bearing will first be thoroughly cleaned and inspected for initial defects. The next step fills the bearing with a soft mixture of graphite and other proprietary binder products. A computer programmed thermal curing process hardens this mixture within the bearing, filling the space between the inner and outer races for the width of the bearing. Excess graphite is cleaned off the bearing after which the bearing is put through a special run-in process. The bearing is then cleaned and quality checked. If the CSL product is to include our EP or EPN additives, it will go through addition procedures to infuse the solidified CSL. One more quality check is conducted and finally each bearing is packaged and prepared for shipment.
Why Can’t Shields Be Put Back On?
Bearing manufacturers lubricate and install shields at their factory. We must remove at least one shield to clean out the factory-infused grease and process a bearing with CSL. We cannot re-install that shield, special tooling is required to properly install a shield. If improperly installed, the shield may come off during operation damaging machinery or at the very least, cause an unscheduled shut down to replace the bearing.
While industry standards dictate the dimensions of bearings, each bearing manufacturer has subtle differences in the size of the shields and landing grooves. Even within a single manufacturer’s line of bearings, the bearings are sometimes made in several different countries, and often the shields for bearings made in one country won’t fit the same bearing made in another country. Spare shields are nearly impossible to come by.
So the ultimate reason we can’t do it, is that it’s just not practical.
The exception is for housed units with flingers which we can usually re-install and conveyor wheels which we can also install shields on.
Why Can’t Seals Be Used?
Seals have two purposes: keep lubricant in; and keep contaminates out. Generally, seals are snapped into landing grooves on the inner and outer races. There are also “low drag” seals which snap into the outer race and rest on a beveled inner race. For seals to work properly the landing groove or the surface the low drag side rides on must have some liquid lubricant present to facilitate low friction drag. This liquid lubricant is not present in CSL. However, CSL needs no seal to keep the lubricant in and, depending on the size of contaminants, it may not need extra seals to keep contaminants out.