Abstract
For the last few years, car manufacturers have been very interested in improving acoustic comfort of their vehicles. Among the different noise items on vehicle, the gearbox noise is one of the less understood, specially the rattle noise, which is caused by gear teeth impacts. This kind of noise is complex to model due to its high non-linearity nature.
The goal of this paper is to introduce elementary shock mechanism, to define the gearbox sensitivity and to link the torsional impact torque to the housing vibrations (proven to be representative of rattle noise) that allows the definition of a transfer coefficient. A torsional model capable of estimating the impact torque is presented, and a simplified gearbox (one gear train) was built to validate this model.
As a conclusion, it is shown how to generalise this study to an industrial gearbox and presented the advantages of this developed process (parametric study, gearing optimisation).