AGMA 19FTM06 PDF

Gear noise is a very important contribution to the overall performance of power transmission systems. The actual gear mesh is the most decisive criterion for noise generation with two aspects: a) impact of gears getting into mesh with the previous mesh being deflected under load resulting in premature mesh begin and/or mesh interference and b) mesh stiffness variation and hereby uneven angular velocity and torsional vibration excitation. Optimized lead and profile modification as well as high values for profile and overlap ratios are basic measures to reduce noise excitation.

There are specific conditions for the multiple gear meshes in planetary gear systems. Focusing on the sun pinion, it can be distinguished between simultaneous and sequential meshing. Many planetary gears are spur gears with higher excitation level than helical gears due to the lack of overlap ratio.

Theory of noise generation in a gear mesh and the specific application on planetary gear systems are described in this paper. The results are illustrated by an example with test bench measurements.