Thermo-molecular Gas-film Lubrication (t-MGL) Analysis Considering Temperature Distribution and Accommodation Coefficients at the Boundaries

- Static and Dynamic Analysis of Finite Width Slider -

Abstract

In a computer hard disk device, flying height in a nanometer order has been achieved due to the gas lubrication action. A new type of flying head slider mechanisms whose air bearing surface (ABS) or disk surface has local temperature distributions such as thermal fly-height control (TFC) and heat assisted magnetic recording (HAMR) have been proposed in order to increase the recording density. Moreover, recently, He-enclosed HDDs have been researched and developed to achieve high performance, because Helium has smaller windage loss and higher heat conductivity than air. Thus, it is becoming increasingly important to analyze the flying characteristics of head sliders over a running disk using the thermo-molecular gas-film lubrication (t-MGL) equation considering temperature distributions and accommodation coefficients at the boundary. In this paper, we numerically calculated the effects of accommodation coefficients on the static and dynamic lubrication characteristics in Air/He as an ambient gas.