Abstract
The recent two-dimensional dynamic analyses on the optic-disc drives have shown a great capability of the automatic ball balancer (ABB) for reducing radial vibration of the rotating assembly of the spindle and disk by counteracting the unbalance of the system. However, these analyses cannot provide satisfactory predictive capability on the dynamic behaviors of the practical optic-disc drives because the rocking motion of the rotor is more pronounced at high operating speeds. This thesis conducts a 3-D dynamic analysis on the system equipped with ABB in order to discuss the rocking motion of the rotor.A simplified physical model and the coordinate systems for describing the non-planar motion are first defined. Secondly, use Lagrange method to derive the equations of motion for the rotor equipped with an ABB. Computer simulations and experiments of the 3-D motion are then carried out to calculate the levels of the radial and tilting vibratory motions of the rotor assembly. Results illustrate that a great deal of improvements have been achieved for reducing the radial vibration as well as the non-planar motion of the rotor system. Finally, some design guidelines are provided for the ABB design engineers.