3. Lubrication

3.1 Necessity of lubrication

In order to optimize a bearing, it is important to study not only the influence of fatigue on service life, but also the environment, i.e. lubrication. Technological advances have made it possible to study the effect of lubrication on service life.

Bearing lubricants must meet three fundamental requirements:

• lubricate by separating surfaces in contact and reducing friction; under satisfactory lubrication conditions, bearing surfaces are separated by a thin film of lubricant which prevents metal-to-metal contact and the resulting friction and wear;

• ensure heat transfer; lubricants are also used to dissipate heat developed at contact surfaces to cooler...