Effect of Spur Gear Damage on Mesh Damping Ratio

In gear systems, current models mostly supposed gear mesh damping ratio was a constant. In real applications, gear mesh damping may not be constant for different tooth contact positions and is dependent on the gear damage. For that reason, the damage effect on mesh damping has been the subject of intensive research and may deserve some investigations. In order to determine whether or not damage contributes significantly to the mesh damping in a one-stage gear system, a general dynamic model is developed, and a numerical simulation is achieved. The continuous wavelet transform method (CWT) is used to provide dominant frequencies and damping ratios for each mode separately which are essential information to learn about the damage effect on mesh damping. Several types of gear defects can be found in the literature. In this paper, a gear eccentricity defect and tooth crack are introduced in the model to study their influence on mesh damping.