Stress distribution over gear teeth after grinding, running-in and efficiency testing

Other conference contribution, 2015

The distribution of surface residual stresses over gear teeth were characterized by means of X-ray diffraction on case hardened gears after grinding, running-in and efficiency testing. Spur gears made of 16MnCr5 steel were tested in a FZG back to back test rig at 94Nm and 302 Nm running-in loads, and efficiency tests. After grinding a non-equal biaxial stress state was found with compressive residual stresses in profile direction more than twice those in axial direction. On one side of the teeth the stresses were uniform, while the other had gradients from tip to dedendum and in axial direction. Running-in increased the compressive stresses in both directions, but the lower load gave higher stresses in profile direction and lower in axial direction. The stresses increased further in profile direction during efficiency testing, while in profile direction they tend to decrease, totally towards rather equal stresses in both directions.