著者

稲垣 洋輔 香川 美仁 森川 広一 岩附 信行 林 巖 細川 俊之

出版者

一般社団法人日本機械学会

雑誌

Dynamics and Design Conference : 機械力学・計測制御講演論文集 : D & D (ISSN:13480235)

巻号頁・発行日

vol.2000, 2000-09-01

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This paper describes the optimization of the case cover of small hard disk drive (HDD) used for personal computers. Small Hard disk drives are one of the main causes of noise radiated from personal computers or workstations. Nowadays the rotational speed of spindle motor used to rotate disks is increased year by year in order to increase the transfer speed. It is afraid that the noise radiated from small HDD is increasing more and more accordingly. Optimization of the shape of ribs which are attached on the case cover are hence tried in order to reduce the noise radiated from small HDD used for personal computers. Firstly, the natural modes of flexural vibration of the case covers of small HDD, which were made of aluminum, steel, and brass, were experimentally determined, and the natural frequencies, mode shapes, and damping coefficients were determined. Secondly, the sound power radiated from the case covers was theoretically estimated dy using the results of FEM modal analysis, was made sure to coincide with the measured values. Finally, the sound powers radiated when the thickness of the case cover was uniformly thickened, and when radial ribs, lattics ribs, or circular ribs were attached on the case cover, were compared. As the results, it has been revealed that the sound power is more reduced as the thickness is increased, the increase of thickness is effective especially to the low modes. For attaching ribs, radial ribs were most effective, and the sound power was more reduced as the number of ribs and/or the height was increased.