A Research on Vehicle Gearbox Whine Based on Multi-Physics Coupling Simulation and Psychoacoustics

Vehicle gearbox whine is a common NVH problem which may directly cause complains from passengers on the quality and performance of vehicle. In order to efficiently and fundamentally control the whine phenomenon, this work first studied the characteristics and mechanisms of the gearbox vibration and noise. The study results revealed that the transmission error of gear was the excitation source of gearbox vibration, and the ambient air was the main transfer path of radiation noise. Then a multi-physics coupling simulation model was built to reveal the interactions among gear, housing and ambient air. This model could also predict the characteristics of the sound field near the passenger’s ear. To take account the psychoacoustic property of human auditory system, this work applied a quality index called tonality to evaluate the severity of gearbox whine. This paper also describes a case study to verify the accuracy and availability of the simulation model. In this case, the whine phenomenon of a practical gearbox was simulated with the proposed model first, and then an optimization on the micro geometry of gear was applied to decrease the noise level to an acceptable level. The main significance of this work is to propose an integrated and effective approach to control the gearbox whine. The indicative conclusions of this work could be referred by NVH engineers in the early phase of vehicle gearbox development.