Takao Terayama

Non-symmetrical three-lobe bearing spindle technology: a drive technology to increase aerial density

A fluid-film spindle for 2.5 inch hard disk drive is described that effectively reduces nonrepeatable runout to less than 0.05 /spl mu/m, making it possible to increase track density. The spindle is used with a newly designed three-lobe bearing of which each lobe is asymmetrical. The influence of stiffness and temperature in a prototype spindle using this bearing are discussed and comparisons are made with a conventional ball-bearing spindle.

Thin Spacing Analysis for Head-Tape Interface

Very thin head-tape spacing, combining contact and floating conditions, is investigated for high density magnetic recording. A generalized lubrication equation, based on a linearized Boltzmann equation, is coupled with the tape deformation equation for analysis. Tape-surface roughness is also taken into account in the lubrication equation. The average flow model is adopted to analyzing tape-surface roughness. For very thin spacing conditions, it is found that the spacing based on the linearized Boltzmann equation is smaller than that based on first-order slip flow, and larger than that based on second-order slip flow. It is also found that considering tape-surface roughness reduces the calculated minimum spacing. Analytical results agreed with the experimental ones.