Abstract
This thesis is devoted to study the dynamic behaviors of the optical disk drive equipped with an automatic ball-type balancer. A mathematical model considering the foundation design is first established based on some proper assumptions, and employs Lagrange’s equation to derive equations of motion for balls and foundation. Then utilize the method of multiple scales to obtain the steady-state solutions. Having completed a stability analysis, the influence of each parameter on the performance of automatic balance system (ABS) in radial vibration reduction is distilled. It’s obtained based on theoretical and simulation results that there are two unstable regions, where balancing balls cannot settle near translational and torsional resonance. To achieve an optimal balancing performance, i.e., the residual vibration is reduced to almost zero, the system must be operated above torsional resonance. Furthermore, shortening the distance between spindle motor and the C.G. of the foundation can eliminate the unstable region near torsional resonant frequency, so that the operating speeds above translational resonance are stable regions. The aforementioned results are verified via experiments as well. Finally, some guidelines on the foundation design and the velocity profile design of the spindle motor are proposed to improve balancing performance and consistence.