Simulation analysis of influencing factors on vibration and noise of a herringbone gear speed-reducer

A dynamic model of a herringbone gear transmission system was developed considering the effects of time-varying mesh stiffness, gear errors, stiffness and damping of plain bearings. The time history and the frequency spectrum of the dynamic bearing force were obtained by solving the dynamic model with Fourier series method. Taking the dynamic bearing force as an excitation, the noise radiation of the gearbox was calculated by using FEM/BEM, and then the noise spectra of different acoustic field points of the gearbox were obtained. The effects of the dynamic property of the gearbox and each frequency component of the excitation on the radiated noise of the gearbox were analyzed. The noise radiations of the gearbox under multi-operation condition were computed, the effects of operating load, mesh stiffness and gear error on the vibration and noise radiation of the gearbox were discussed, and then the varying laws of the noise radiation with operating load, mesh stiffness and gear error were obtained. The results provided a useful theoretical guideline for design of gearboxes.