Technical Committee Lubricants

Investigation of the influence of load cycles and lubrication mode on the micro-pitting load capacity for lubricant testing

The FVA-FZG-micro-pitting test is well established as the standard test method for evaluating the micro- pitting characteristics of lubricants used in gear drives. This test method provides precise results, but requires relatively high costs and is quite time consuming. Unfortunately an efficient and consistent short test method has been missing yet. Therefore the available FVA-FZG-micro-pitting test should have been supplemented by a standardized short test method, that is able to classify candidate lubricants analogous to the FVA-FZG-micro-pitting test.
Within the scope of this research project the DGMK-FZG micro-pitting short test GFKT-O18,3190 was developed and tested with lubricants, whose classification in the standard FVA-FZG-micro-pitting test is well known.
The new DGMK-FZG micro-pitting short test categorizes candidate lubricants in classes of micropitting load capacity analogous to the FVA-FZG-micro-pitting test. These classes correlate well with the classes of the FVA-FZG-micro-pitting test. Regarding the general tendency, as expected the average maximum profile deviation after running the DGMK-FZG micro-pitting short test decreases with increasing micro-pitting load capacity of the oil according to the FVA-FZG-micro-pitting test. The correlation between the average maximum profile deviation after running the DGMK-FZG micro-pitting short test and the failure-load stage of the FVA-FZG-micro-pitting test is good.
Consequently the DGMK-FZG micro-pitting short test, as a supplementation to the available standard FVA-FZG-micro-pitting test, represents a standardized short test method, that is qualified for the differentiation of various candidate lubricants in terms of their micro-pitting load capacity.