Many indicators of the performance requirements of the bearing grease colloidal stability (sub oil), the combined result of mechanical stability (100,000 times shear test, the extended the work cone penetration value) and oxidation stability, these three indicators, that is, the bearing life.

The operation of the grease in the bearing is subjected to the destruction of the mechanical force so that the fibers of the thickening agent varying fragmentation, shorter, reducing the ability to maintain the grease structure, i.e. consistency change, if the consistency changes Assembly generated the phenomenon of loss from the work surface , while in the driving operation when the grease will be subject to the influence of elevated temperatures, the base oil will produce evaporation and reduce or part of the base oil due to lipid colloidal destruction of the oil loss reduced so that the oil content of the grease, also may produce oxidative deterioration.

Bearing grease work after the grease base oil content less than 60% -70% (that is, the base oil due to evaporation or the oil lost 30% -40%) will reduce or even lead to the loss of lubricating ability bearing the operation fails, while the decline in the consistency of the fat and the oxidation and deterioration more will influence the work of the bearing in operation.