A Nontraditional Vibration Analysis of Rotating Disk/SpindleSystems and Its Applications to Computer Hard Disk Drives

本研究的主要重点是开发一种新的数学模型来解释和预测在磁盘驱动器实验中观察到的非传统的振动共振。 这一新的数学模型被用来解决磁盘驱动器行业中出现的五个振动问题。它们包括阻尼、强迫响应、磁盘/主轴/磁头相互作用、啸叫噪声控制和非线性流体膜轴承。在过去几年中，制造和电子技术的进步已经通过增强数据存储密度（例如，4000磁道/英寸）和通过堆叠更多的盘（例如，10个磁盘）到现代磁盘驱动器。与此同时，计算机行业继续通过使用安装在具有较短轴承跨度的主轴上的更小和更薄的磁盘来减小磁盘驱动器的尺寸和重量。由于这些设计趋势，在实验中反复观察到具有显著振幅的小于500 Hz的振动共振。这些振动共振对它们的性能是极其有害的，因为它们的低频率和大振幅阻止记录头正确地和重复地阅读或写入数据。这个新的数学模型比现有的模型更现实，因为它考虑了多个柔性磁盘上的刚性主轴，有两个柔性轴承支持。通过华盛顿大学动力学和振动实验室提供的全尺寸磁盘驱动器测试台，实验验证了理论预测。

The primary focus of this research is to develop a new mathematical model to explain and predict the nontraditional vibration resonances observed in disk drive experiments. This new mathematical model is agumented to resolve five emerging vibration problems in the disk drive industry. They include damping, forced response, disk/spindle/head interaction, control of squealing noise, and nonlinear fluid- film bearings. In the past several years, advances in manufacturing and electronic technologies have substantially increased the capacity of computer disk drives by enhancing the data storage density(e.g., 4000 tracks per inch) and by stacking more disks (e.g., 10 disks) into modern disk drives. In the meantime, the computer industry continues to reduce the size and weight of disk drives by using smaller and thinner disks mounted on spindles with shorter bearing spans. As a result of these design trends, vibration resonances less than 500 Hz with significant amplitudes have been observed repeatedly in experiments. These vibration resonances are extremely detrimental to their performance, because their low frequencies and large amplitudes prevent the recording heads from reading or writing the data correctly and repeatedly. This new mathematical model is more realistic than the existing models, because it considers multiple flexible disks on a rigid spindle that has two flexible bearing supports. The theoretical predictions are verified experimentally through a full-scale disk drive test rig available in the Dynamics and Vibration Laboratory at the University of Washington.