Lubrication is necessary to ensure proper bearing performance. Grease lubricants are comprised of both a base oil and thickener. Oil lubricants do not contain a thickening agent. Thickeners act as a sponge to retain the base oil and keep it in place. A large assortment of additives can be added to the thickener to add several benefits such as preventing oxidation, handling extreme pressure, etc.
Typically, greases will have a semi-solid to solid consistency that allows it to stay in place within the bearing longer than oil. It is in this aspect that grease holds an advantage over oil. The typical grease fill within RBI bearings is between 25 and 35 percent. A minimum grease amount is important to allow for the bearing to remain lubricated throughout its entire service life. However, a limit must be placed on how much grease is used because an excessive volume of grease can lead to an increase in heat generation during operation. For extreme operation conditions, RBI Bearing’s engineering staff is available to answer your questions by calling 1-800-708-2128, M-F 7:30-5:00 (CST) for recommendations on grease fill. Information regarding some of our commonly used greases can be found here.