Optimizing Bearing Lubrication can Extend Bearing Life, Reduce Costs

• Published in: Waterworld (Tulsa, Okla.) Vol. 23; no. 2; p. 12
• Main Author: Budris, Allan R
• Format: Magazine Article
• Language: English
• Published: 01.02.2008
• ISSN: 1083-0723

Pump bearing failures are the second leading cause of pump repairs, after mechanical seals. Most pump bearings do not reach their theoretical (L10) fatigue life. Two-thirds of all rolling element bearings in service which had to be replaced, failed prematurely. Only one-third of bearings fail due to fatigue spilling (L10 Life). The two-thirds that failed prematurely break down as follows: ? One-sixth of bearings fail due to: - incorrect fitting - incorrect selection - damage due to external causes (such as vibration, stray electric currents, or overloading) ? One-third of bearings fail early due to lubrication problems. ? One-sixth fail due to contamination entering the bearing. This is a most troublesome factor because contaminants are everywhere. Typical contaminants are: - Air - Water (A small amount will significantly reduce bearing life, see figure 1) - Cleanup / process chemicals - Particulates It has been estimated that the life of roughly one-half of all pump bearings could be extended by better, or optimized lube application. More advantageous application methods are readily available and, for the most part rather inexpensive. The two most effective lubrication upgrades are synthetic lubricants and oil mist.