Manufacturing Robustness Analysis of the Noise Excitation and Design of Alternative Gear Sets

Transmission errors, axial shuttling forces, and friction result in bearing forces that serve as the major excitations of gear noise. This paper focuses on a comparison of these factors, as well as stresses for two designs: one being an original product design and the second being a slightly finer pitch design that has the equivalent design life of the original design. The original gear design shows higher transmission errors and bearing forces, thus creating more noise than the finer pitch gear pair. It was noted from testing that no matter how the profile and lead modifications to the original coarse pitch gear pair were changed, it was difficult to make it quieter. On the other hand, no matter how the profile and lead modifications to the finer pitch gear pair were changed, it was difficult to make it noisy. This paper shows the effects of different profiles and leads for the gear pairs on noise excitations and stresses. Furthermore, a robustness analysis that shows the sensitivity of the two designs to manufacturing errors is presented. The analyses essentially corroborate the experimental observations.