Rattle detection in gearing systems by noise and vibration measurements

Rattle noise in a gear train is defined as an undesirable noise that occurs due to the impact between the gear teeth. This work aim to apply methodologies for detecting rattle noise in powertrain transmissions through the processing of microphone and acceleration signals. An experimental campaign was conducted on an off-road vehicle within a truck that was capable of reproducing the real operational conditions. Two kind of operational conditions were investigated: the constant velocities and the time instants of changing gears. The campaign employed experienced operators to identify scenarios with and without rattling. Consequently, rattle indices were applied to the experimental measurements of acoustic pressure and acceleration. The results allowed for the identification of rattle noise conditions, especially if applied to vibration data. Furthermore, the effectiveness of a modified configuration has been tested, both with subjective evaluations and, thus, with the rattle indices.