A Study on Positioning Error Caused by Flow Induced Vibration Using Helium-Filled Hard Disk Drives

In this paper, we compare the positioning accuracy of helium- and air-filled drives. We report the PES spectra of the both drives and calculate the mechanical disturbance. The results reveal that almost all disturbances in higher rpm drives are flow induced vibrations and that disturbances in helium-filled drives are dramatically smaller. The experimental positioning error of helium-filled drives is less than half of that of air-filled drives. The static and dynamic fluid computations explaine these experimental results.