Figures of merit for dynamically unloaded air bearing sliders©

A modeling technique is described whereby a static air bearing solver can be used to predict the suitability of an air bearing design for dynamic load/unload applications. Several subambient pressure air bearings, with varying degrees of nominal suction force, are evaluated for their quasi-static unload trajectories. Experimental data, obtained using a high speed camera, are used to verify the predicted peak lift-off force during unload. Results from theory and experiment indicate that it is possible to design sub-ambient pressure air bearings to be suitable for dynamic load/unload applications, provided that the appropriate figures of merit are achieved. These include a non-negative net air bearing load an increasing pitch attitude, and a non-excessive roll angle throughout the unload trajectory. A design that meets these criteria is described.