The experimental work carried out was aimed at developing a test method that was able to consistently
produce micropitting damage and could discriminate between a good oil (i.e., one that rarely produces
micropitting in service) and a poor oil (i.e., one that does produce micropitting in service). The small–scale
3–Disc test rig that was used for this work employs 3 discs to apply the test load to a 12mm–diameter test
roller. This test geometry allows a large number of stress cycles (typically 600,000 to 800,000 cycles/h) tobe
generated at the contact track on the roller.
The disc rig control system allows test parameters such as entrainment velocity, contact stress and slide/roll
ratio at the disc/roller contacts to be accurately and independently controlled. This enables the effect of key
parameters to be studied in isolation, which is something that cannot be easily achieved using conventional
gear test rigs.