Experimental study of gear rattle excited by a multi-harmonic excitation

This paper deals with the rattle noise, caused by the fluctuations of the engine torque (acyclic excitation) which, under special conditions, can cause multiple impacts inside the gearbox. Its aim is to experimentally describe the rattle phenomenon in a gearbox. First, a fully instrumented test rig consisting of a simplified gearbox was designed in order to recreate the rattle noise phenomenon for a multi harmonic excitation imposed to the input shaft of the gearbox. Second, different gearbox configurations were used to characterize the rattle threshold and the rattle noise evolution, in relation to excitation parameters and mechanical gearbox parameters. Third, a simplified model of the rattle phenomenon is drawn, using a Kelvin-Voigt model, aiming to determine the most significant parameters influencing the rattle noise.