The bending-torsional vibration characteristics of gear transmission under the effect of tooth surface roughness

A correlation was established between the sample length and gear speed, and time-varying roughness characteristics were recorded at specific speeds (referred to as time-varying roughness). We investigated how the measured tooth surface roughness influences both the gear errors and the tooth surface friction coefficient. The mathematical representation of the measured roughness was illustrated using statistical analysis procedures. Drawing from fractal theory, we developed a gear error correction model that considers the effects of the time-varying roughness. We introduced a correction mechanism for both time-varying roughness and error into the Xu model. Additionally, we presented a method to calculate the tooth friction coefficients while taking into account the statistical characteristics of tooth surface topography. A numerical analysis was then carried out to investigate the effect of time-varying roughness and gear error on the tooth friction coefficient. Taking into account the influence of the measured tooth surface roughness, we built a gear analysis model by applying the lumped mass method. The effects of the measured roughness on the gear transmission process were analyzed using numerical analysis. A bench test was designed and executed to evaluate the vibration traits of the gear system. The maximum discrepancy between the test and numerical outcomes was 25.21 %. This article provides theoretical and data support for the dynamically optimal design of gear transmissions.