Increasing normal contact damping through fine particle shot peening for vibration reduction of gear system

Abstract

With the increasing operating speeds of electric drive systems in new energy vehicles, reducers are becoming more susceptible to vibration and noise. Consequently, effective vibration suppression has become a critical challenge. This study proposes a new approach to suppress gear system vibrations by increasing normal contact damping through regulating gear surface morphology using fine particle shot peening (FPSP). To accurately characterize the surface features altered by FPSP, a conical asperity hypothesis is introduced. Based on this hypothesis and the gear meshing process, a fractal-based contact damping model is developed and experimentally verified. Results show that FPSP treatment markedly increases the gears’ normal contact damping, and a peening pressure of 0.3 MPa yields the most significant improvement. The vibration tests for a single gear pair show that the vibration of gears treated by FPSP is significantly reduced, with the vibration acceleration of gears peened at 0.3 MPa decreasing by 35%. Furthermore, the bench test indicates that, under the normal operating conditions, the reducer composed of FPSP gears can deliver stable vibration reduction performance across a wide range of operating speeds. This work offers a new, effective, and practical solution for vibration suppression in electric drive systems of new energy vehicles.