The Grease Life Factor concept for ball bearings

Bearing fatigue life is calculated using a so called basic rating life equation L-10 = (C/P)(p) where the operating load is translated into an equivalent load P and divided by the bearing capacity. This makes it possible to test the bearing capacity C under an arbitrary load and therefore on almost any test rig. For grease life such a concept does not exist. Grease life is specified by a number of hours running on standardized test rigs and conditions. A similar concept as for bearing life is introduced in this paper for lubricating grease, called the 'Grease Life Factor' (GLF) concept. It is based on a grease life model for axially loaded grease lubricated ball bearings and makes it possible, similar to bearing life, to quantify the life properties of a grease using 'any' grease life test rig. It also implies that there is no longer a need to specify grease life for standardized test rigs. The validity is illustrated with test data obtained from the most widely used test methodologies: FE9 and R0F.

Automated summary

Bearing fatigue life is calculated using a basic rating life equation, while grease life is specified by hours running on standardized test rigs. The concept of 'Grease Life Factor' (GLF) is introduced in this paper for grease life, allowing for quantification of grease life properties using any test rig. This eliminates the need to specify grease life for standardized test rigs.