Experimental research on noise source identification and the radiation characteristics of a gearbox based on NAH

The method of near-field acoustic holography (NAH) was applied to identify the noise source of a certain vehicle gearbox. The main internal excitation sources and the external radiation sources of noise were located by analyzing sound power spectra and holograms of the gearbox surfaces. On that basis, main rules and influence factors of the noise radiation were obtained through discussing radiation characteristics of the gearbox. The experimental research lays a solid foundation for the further research of noise reduction of the gearbox.