피딩 데크의 강체운동이 자동 볼 평형장치가 장착된 광디스크 드라이브의 안정성에 미치는 영향

Abstract

Dynamic stability of an automatic ball balancer equipped on the feeding deck of optical disk drives, for instance, CD-ROM or DVD drives, is investigated. The non-linear governing equations, which describe the translational and rotational motions of the feeding deck as well as the positions of balancing balls, are derived using Lagrange’s equation. Applying the perturbation method to the non-linear equations, the linearized equations of motion in the neighborhood of a balanced equilibrium position are obtained. These are coupled, ordinary differential equations with time-dependent periodic coefficients. By using the Floquet theory the effects of the stiffness and damping of dampers on the structure’s dynamic stability are investigated for the variation of the rotational speed. It is finally found that not only the natural frequency of the translational motion but also that of the rotational motion has an influence on the balancing performance of the automatic ball balancer.