Air Bearing Slider Simulation and Modeling for Hard Disk Drives with Ultra-Low Flying Heights

As non-traditional application of hard disk drives (HDDs) emerges, their mechanical robustness under shock and other mechanical disturbances during different states are of great concern [1–3]. Normal drives can not malfunction during the operating state, damage during initial assembly, testing, installation and all unfavorable situations caused by final users. As the areal recording density increases in HDDs, the flying physical spacing between the head/slider and the disk media decreases and the likelihood of head/disk contact during full speed rotation increases. Therefore, the simulation and modeling of the stiffness effect of the air bearing slider with ultra-low flying heights becomes an important issue for the operational shock simulation. The static/dynamic properties, including the influence of the radial position and the skew angle of the slider, the rotating speed of the disk, and the shock simulation, of the air bearing slider were analyzed by CML code. An single-degree-of-freedom (SDOF) model of the air bearing slider was developed to provide a basic understanding of the nonlinear effects of the air bearing for ultra-low flying heights. Generally speaking, for a given rotating speed of the disk, as the slider moves from the inner diameter (ID) to the outer diameter (OD), the maximum contact pressure, the skew angle, the pitch, and the maximum air bearing pressure increase; while the flying height, and the roll angle decrease. These trends are strengthened by a faster rotating speed of the disk. There are obvious oscillations in the air bearing force, the minimum spacing, and the displacement at the trailing edge center (TEC) when contact occurs during a shock. There are obvious oscillations in the air bearing force, the minimum spacing, and the displacement at the trailing edge center (TEC) when contact occurs during a shock. More than one resonant frequencies (peaks) were observed by giving a large initial perturbation to the SDOF model. The air bearing slider has obvious nonlinear behavior for ultra-low flying heights.