摘要 |
A pivoting armset assembly is disclosed herein that has substantially reduced misregistration due to thermal effects. The armset assembly is useful for an actuator in a magnetic disk drive; the preferred embodiment is an armset assembly in an actuator for reading from, or writing to, one or more magnetic storage disks. The armset assembly, constructed according to the present invention, includes an armset having a smooth bore aligned with the axis of rotation. The assembly further includes a sleeve having a smooth outer perimeter with a size for an interference fit within the smooth bore. An anti-friction material is positioned between the smooth sleeve and the smooth bore. The assembly also includes a bearing disposed within the sleeve, to pivot the arm about its axis. The coefficient of friction between the bore and sleeve is high enough that they rotate together as a unit throughout their operating temperature range, without creating radial clearance between the arm and the sleeve, but low enough to permit slight axial adjustments during thermal expansion in which the bore expands at a different rate than the sleeve. Preferably, the anti-friction material is disposed on the sleeve, and includes a coating of tungsten disulfide (WS 2). The coefficient of friction can be selected by a choice of the heaviness of the interference fit, the type of the anti-friction material, and the smoothness of the bore and the sleeve.
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