Design and Analysis of a Gear Rattle Test Rig

Gear rattle in manual transmission systems is a complex phenomenon and problematic to transmission and vehicle manufacturers. In the last three decades some inroads have been made in applying analytical and numerical analysis to understand rattle, however solutions and design methodologies for low rattle or no rattle are elusive. Problems with rattling transmissions continue to plague the industry. Controlled experiments for transmission rattle are required for research, to aid in the development of design tools and for validation of these tools. This paper presents a test rig which utilises a Hooke's joint to induce the torsional oscillations that lead to rattle. The design process relies on torsional lumped mass modeling and linear and transient nonlinear analyses and this paper details how the correct specification of the required driving motor isolation system is achieved. The rig complements the ongoing development of advanced rattle simulation tools and design methodologies and is intended for validation and research work.