Abstract
For small multipurpose industrial vehicles in particular, the perceived quality in terms of ride comfort and interior noise is becoming an aspect of fundamental importance necessitating that, during the design process, vehicle manufacturers evaluate its vibrational and acoustic performance in operational conditions in order to enable the expectations of the customer to be anticipated and respected.
The main contributions to the internal noise are powertrain (engine and transmission), tyre and its interaction with the road surface and aerodynamic noise, the balance of which depends strongly on the conditions of operation. Often, over the medium speed range, for example, the noise emitted by the transmission system tends to become more evident with characteristics which may be considered particularly detrimental in terms of sound quality inside the vehicle.
The activity described in this article focuses on the optimisation of the product and process methodology of gear design and manufacture for the differential system, through the different steps of design optimisation, to the final test of acoustic emission. Correspondingly one of the principal aims of the project was the experimental evaluation of noise emitted by transmission system, and to understand which components may be critical and how the vibrations are transmitted through the structure to result as noise at the passenger ear.