Vibration Characteristics of Optical/Magnetic Disk Drive Subjected to Base Excitation

这项研究的目的是获得防止外部振动的磁盘驱动器的机械设计原则。从理论上分析了磁盘驱动器在基座激励下的振动特性。在圆盘-主轴系统的解析模型中，圆盘被视为转动的弹性环形薄板，主轴电机的轮毂被视为转动刚体，主轴电机的轴承被视为弹性和阻尼件。将转盘对基础激励的挠度表示为本征函数级数，其中本征函数以旋转波的形式给出。分别得到了转盘-主轴系统在轴向平移、正向摆动和向后摆动时的响应表达式。提出了转盘-主轴系统固有频率的图解法。此外，在分析模型的自由度中加入了径向位移，并考虑了圆盘的面内运动。在理论分析和数值计算的基础上，讨论了轮毂惯量、轴承柔度和主轴结构对系统固有频率和稳态响应的影响。文中还讨论了阻尼效应和陀螺效应的影响。对一个裸光盘和一个主轴电机进行了实验，实验结果验证了本文分析的正确性。

The purpose of this study is to obtain the principles of mechanical design for disk drives which are secure against external vibrations. Vibration characteristics of disk drives in operation subjected to base excitation are theoretically analyzed. In the analytical model of disk-spindle system, a disk is treated as an uniform thin elastic annular plate in rotation, a hub of a spindle motor is treated as a rotating rigid body, and bearings of a spindle motor are treated as elastic and damping components. Formulation of the deflections of the rotating disk to base excitation is derived as an eigenfunction series where the eigenfunctions are given in the form of rotating waves. The expressions of the response of the rotating disk-spindle system for an axial translation, a forward whirl motion of tilting, and a backward whirl motion of tilting are obtained separately. The graphical method for the natural frequencies of the rotating disk-spindle system is proposed. Moreover, the radial displacements are added to the degrees of freedom of the analytical model, and inplane motion of the disk are also considered. On the basis of the analytical consideration and numerical results, the effects of hub inertia, bearing flexibility, and spindle configuration both on the natural frequencies and on the steady-state response are discussed. The effects of the damping and the gyroscopic effects are also discussed. The experiments were carried out for a bare optical disk and a spindle motor, and the experimental results have varified the validity of the present analysis.