Experimental Evaluation of Stiffness and Damping of Slider-Air Bearings in Hard Disk Drives

Abstract

The system identification method was applied to experimentally investigate the dynamic characteristics of slider-air bearings in hard disk drives. The transient responses of sliders were measured, and the modal frequencies and damping ratios that are directly related to the stiffness and damping of the bearings were obtained by data processing and parameter identification. The dynamic property of a particular advanced air bearing (AAB) slider was measured and compared with simulation results. It was found that, contrary to usual perception, the suspension assembly significantly affects the dynamic characteristics of the air bearings. Contacts between the load beam and the flexure may introduce a larger damping and nonlinear property. The preliminary results also show that the proposed method is robust for experimentally evaluating the dynamic properties of slider-air bearings.