Dependence of tooth flank finishing on powertrain gear noise

Finishing processes can be used in order to reduce manufacturing errors on teeth flank surfaces. These surfaces are at the heart of the gear meshing mechanics and thus should have an impact on gear noise. This paper addresses the issue of the impact tooth flank finishing on noise and vibration. The topographic and vibratory performances of two finishing processes, grinding and powerhoning, were compared. Multiscale analysis through continuous wavelet decomposition was used in order to characterize the teeth surfaces as well as the vibration spectra of a powertrain transmission tested on an industrial bench in a wide range of rotational speeds and frequencies. Results show that flank finishing processes leave their signature on the teeth surfaces which impact the vibratory behavior of the gear. Moreover, multiscale analysis approach allows the separation of vibration sources (meshing, environment, etc), and permits to quantify the impact of the choice of the finishing process.