Bearing life theory has been further refined to use a family of curves to establish an adjustment factor to the unmodified life. Of primary importance is the N factor used to correct for contamination. An accurate assessment of the N factor requires an analysis on a computer with accurate knowledge of the application. These refinements, along with similar actions taken by other manufacturers, can only lead to a more precise determination of bearing life. In addition to new life prediction theories, new lubricants and lubrication methods are being devised which will extend the operating life.
Synthetic greases are capable of extending grease life significantly.
Although grease life is a function of more than just oxidation life, it is a good indicator of the type of gain that can be made by using synthetic grease. Synthetic greases can be formulated with a lower sensitivity to temperature variations, and therefore have a larger useful temperature range and the potential for lower losses. The question frequently asked about greases deals with their compatibility if they are mixed during the relubrication process. Table 1 is a guideline to assist in this process. Five key areas should be considered in relation to one another to accurately diagnose the root cause of bearing failures.