In machine tool main spindles, grease-lubricated hybrid spindle bearings can now achieve speed characteristics that until a few years ago were only possible with oil-air lubricated bearings. While dispensing with compressed air as the pumping medium has ecological and economic advantages, the central disadvantage of grease lubrication is the disproportionate reduction in grease operating life with increasing speed. In principle, this problem can be solved by using grease relubrication systems. However, currently available greases with the highest speed suitability are only suitable for use in grease relubrication systems to a limited extent. At the same time, it has not been fully researched how the grease supply to the bearing can be optimally designed.
Research report published: Grease relubrication of rolling bearings at maximum speeds
BMWK-funded project completed
The objective of the research project was to extend the application range of grease-lubricated hybrid spindle bearings by using a grease relubrication system. To achieve this goal, an improved grease relubrication system was developed and the effect of the retention time of the grease in the relubrication system was investigated. The BMWK-funded research project has been completed and the results published in DGMK Research Report 775. The report can be ordered free of charge directly from the DGMK.
Laboratory for Machine Tools and Production Engineering (WZL) of RWTH Aachen University
Chair for Machine Tools
The IGF project (18206 N) of the research association DGMK Deutsche Wissenschaftliche Gesellschaft für nachhaltige Energieträger, Mobilität und Kohlenstoffkreisläufe e.V.. Große Elbstraße 131, 22767 Hamburg, Germany, was funded by the German Federal Ministry of Economics and Climate Protection through the German Federation of Industrial Research Associations (AiF) as part of the program for the promotion of joint industrial research (IGF) on the basis of a resolution of the German Bundestag.