1. Effect of Track-Seeking Motion on Off-Track Vibrations of the Head-Gimbal Assembly in HDDs.
- Author
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Zhang, Guoqing, Li, Hui, Shen, Shengnan, Trinh, Tan, He, Fengliang, and Talke, Frank E.
- Subjects
HARD disks ,VIBRATION (Mechanics) ,COMPUTER simulation ,FLUID dynamics ,ANGULAR acceleration - Abstract
The lateral flow in hard disk drives is greatly disturbed because of the arm swinging rapidly during track seeking, which can greatly affect off-track residual vibrations during track following of the head-gimbal assembly (HGA), as well as the slider. Until now, no simulation studies have been performed to investigate off-track residual vibrations of the HGA that consider lateral flow effects. In this paper, the effect of track-seeking on off-track residual vibrations of the HGA is investigated for air and helium environments using the so-called “fluid dynamic mesh” and the “fluid-structure interaction” methods for the first time. Three different angular acceleration profiles (a square wave, a triangular wave, and a sinusoidal wave) are investigated as a function of seek time (10 and 5 ms). Results show that the smoothening of sharp transitions in the seek profile improves the performance of off-track residual vibrations and shortens the track-following time of the head positioning servo system. In addition, the effect of lateral flow (windage) on off-track residual vibrations must be considered for a square-wave angular acceleration profile. Simulation results show that helium improves the track-following accuracy compared to air because of the lower windage forces acting on the HGA. We observe that the sinusoidal-wave angular acceleration performs best for the three angular acceleration profiles investigated. Furthermore, seek time is found to have only a small effect on off-track residual vibrations during track following. [ABSTRACT FROM PUBLISHER]
- Published
- 2018
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