MoP-9 THERMO-MOLECULAR GAS-FILM LUBRICATION DYNAMICS CONSIDERING BOUNDARY TEMPERATURE AND AMBIENT GAS : 2-DOF NUMERICAL ANALYSIS BY t-MGL EQUATION

抄録

Static and dynamic flying characteristics of a slider in hard disk drives have become an important issue owing to increase in recording density. In the present paper, the characteristics of a step slider flying in either air or He over a running boundary wall with local temperature distributions and thermal deformation (projection) of the slider are analyzed using the thermo-molecular gas-film lubrication (t-MGL) equation. The decreases in minimum spacing for the slider flying in He are significant, because the mean free path of He is approximately three times that of air. The increases in minimum spacing due to laser heating are negligibly small in both air and He, because the heat spot size is very small. Moreover, the decrease in minimum spacing produced by thermal deformation in TFC slider is reduced by total additional pressure of i) MGL pressures produced by the air-film wedge effect, ii) t-MGL pressures by the temperature distribution and iii) van der Waals attractive pressure by small spacing. The spacing fluctuation caused by running wavy disk is reduced, because the inlet to outlet spacing ratio (h_1/h_0) increases.