Micropitting on cylindrical gears
Under unfavourable lubrication conditions, areas with material fractures can occur at the tooth flank of hardened gears. That gives the tooth flank a matt grey appearance. Under progressive micropitting, more and more particles break out. This leads to a change of the profile of the tooth and influences load distribution, gear dynamic, lubrication, and mechanical strength of the surface layer.
The influences (e.g. surface roughness, material, operating conditions) on the damage development and the effects of micropitting on the load-bearing capacity are examined in step and fatigue tests with the FZG back-to-back gear test rig. Especially micropitting test methods, developed at the FZG, make it possible to examine the load capacity of lubricants (base oil and additive).
•   examination of influences on load capacity and service life (e.g. FZG micropitting test)
•   Clarification of the mechanisms of formation and advanced modelling
•   Further development of the calculation methods