In the field of rheology and elastohydrodynamic lubrication (EHL), the research focus is on understanding the physical relationships that occur in lubricated highly loaded contacts of machine elements (for example rolling bearings, gears and cam followers). These are explored both theoretically through the formation of computational models and through experimental methods.
One focus is on the friction losses that occur in EHD contacts and are significantly influenced by the behavior of the lubricants under high pressures, temperatures and shear rates. By investigating the lubricant behavior as well as the interactions of the individual contact partners, the understanding of the losses in such machine elements can be increased and at the same time a possibility to reduce these losses can be worked out. Furthermore, the findings can be used to better understand wear processes and thus enable a reduction of wear in the long term.
Furthermore, in the field of lubricants, the flow behavior of the lubricants and the influence of the operating conditions in the area close to the contact are investigated in order to obtain information about the lubricant film formation and losses. For example, investigations are carried out into lubricant film formation in lubricated oscillating EHD contacts, where the focus is on the physical properties of lubricating greases (the figure above shows the flow of the grease in the area close to the contact during reversing operation).
Thus, the description of the lubricant in physical models -and thus the better understanding of this machine element- is the core of the research. Usually, the behavior of the lubricant is studied with the aid of model experiments, such as the two-disk test rig or the ball-on-disk experiment. Such investigations are supplemented by measurement or direct observation of the processes in EHD contacts, e.g. with the aid of laser-induced fluorescence, infrared thermography and interference methods.
The application of the developed models takes place in the context of projects in which these models are used in real contacts and also serve the optimization of the same. Examples are the application in roller-board contacts of tapered roller bearings, rolling element raceway contacts as well as wrap-around contacts in CVT transmissions.
The knowledge gained is passed on via publications and conference visits as well as in the area of teaching to students in the lectures Tribology 1, Advanced Tribology, Rheology and Numerical Methods.
Team
30823 Garbsen
30823 Garbsen
