被動式渦電流阻尼器應用於光碟機之寬頻減振

Abstract

近幾年來，政府極力提倡節能減碳。本研究利用被動式渦電阻尼器減振，將永磁振動之機械能轉換成電能。此阻尼器主要由永磁與導電材料構成，當導電材料在磁場中移動，或者導電材料處於隨時間變化的磁場中，導電材料上會感應生成渦電流，渦電流產生之磁場與永磁磁場間之磁力會減緩永磁與導電材料之相對速度，發揮阻尼效果，此阻尼力與永磁相對於導電材料之速度成正比。為了找出最佳抑制振動之機構，本論文針對不同的渦電流阻尼器，考量包括外形及架設位置，進行模擬分析，觀察不同情況渦電流阻尼器產生之阻尼力大小，以模擬的結果為基礎設計減振機構，利用MATLAB計算機構受週期性外力作用下其位移變化，並以實驗驗證其減振效果。

Recently, the government advocated vigorously the energy conservation to reduce carbon. This study aims to reduce vibration by utilizing eddy current dampers. Mechanical energy of the permanent magnet vibration transfers into the electrical energy. Dampers of this type function through the eddy currents that are generated when a nonmagnetic conductive material is subjected to a time changing magnetic field. These eddy currents circulate in such a way that they induce their own magnetic field. The polarity of the eddy current field varies such that the force between it and the applied magnetic field always causes a force opposite to the velocity of the conductor. These currents dissipate energy as they flow through the resistance of the conductor. The resulting drag force on the conductor is proportional to its velocity relative to the field. The machine vibration is always serious in low frequency and resonant frequency, we observed that eddy current dampers suppress vibration effectively in those frequency. In order to find the optimum mechanism design, we simulate several kinds of mechanisms concerning different positions and shapes of the conductor, and calculate the displacement with MATLAB. Finally, we verify results with experiment.