Squeeze Film Effect and Hydrodynamics for Ultra-thin Gas Film Lubrication at the Head/disk Interface in Hard Disk Drives

In order to solve the convergence problems in solving the Reynolds’ Equation for ultra-thin gas film lubrication numerically and to avoid the complex programming process, a PDE-based method for solving the equation was proposed in the study. The pressure distributions on the air bearing surfaces for Tri-pad positive and negative sliders with different gas film thickness at the transient and steady state during loading/unloading process were calculated, respectively. The air bearing force then was obtained based on the simulation results. The effects of the squeeze film and dynamic pressure on the air bearing force at transient state were compared with the effects at steady state. The simulated results indicated that the proposed method had good accuracy and fast convergence characteristics for the description of air bearing force. It provided a convenient and accurate method to study the dynamic performance of ultra-thin film lubrication for the head/disk interface with complicated profiles.