Abstract
This paper presents the noise reduction of the machine product with fan noise by reducing structure-borne sound. Also we propose a new method for identifying the contributions of air- and structure-borne sounds in machinery noise. The contribution analysis method is based on the estimation of the structure-borne sound which is predicted by using experimental SEA. Firstly, the contribution analysis method is newly introduced. Next we apply the method to identifying the sound contribution of a breast milk warm machine which has a motor and a sirocco fan for blowing hot air circulated inside of the machine. The contribution analysis results are verified by the comparison with the measurement results in which the structure-borne sound is less generated. Finally it is shown that the noise level can be reduced by controlling the structure-borne sound.
