The widespread use of grease lubrication
in high-speed spindle bearings has been limited by its
insufficient life. An extended grease life is required to
meet the increasing demand of machine tool applications.
Dominant grease properties are determined to attain
longer life at higher speeds for spindle bearings. Part of
the process includes rheological pull-off and oil bleeding
tests, defining active grease reservoirs. The validation has
been successfully carried out in a series of angular
contact ball bearing (ACBB) grease life tests. The
selected grease that fits the defined parameters has shown
long life at speed factor, 2 million ndm.