Browse Prior Art Database

Circular Fin Between Disks for Reducing the Disk Flutter

IP.com Disclosure Number: IPCOM000120183D
Original Publication Date: 1991-Mar-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 1 page(s) / 44K

Publishing Venue

IBM

Related People

Fromm, JE: AUTHOR [+2]

Abstract

It is known that the unsteady air flow in disk drives can induce disk flutters. Experimental results relate this unsteady flow to the vortical and turbulent flow in the region near the disk edge. Lowering the turbulence level in the disk-edge region, e.g., by placing the shroud close to the disk stack, has been demonstrated to be effective in reducing the disk flutter. This disclosure describes a device which will further reduce the disk flutter by suppressing the vortical and turbulent flow. In its embodiment, Fig. 1, a circular fin (1), which is extended from the shroud (2) inward toward the hub (3), is to be inserted between the disks (4) completely or partially off the disk periphery.

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Circular Fin Between Disks for Reducing the Disk Flutter

      It is known that the unsteady air flow in disk drives can
induce disk flutters.  Experimental results relate this unsteady flow
to the vortical and turbulent flow in the region near the disk edge.
Lowering the turbulence level in the disk-edge region, e.g., by
placing the shroud close to the disk stack, has been demonstrated to
be effective in reducing the disk flutter.  This disclosure describes
a device which will further reduce the disk flutter by suppressing
the vortical and turbulent flow.  In its embodiment, Fig. 1, a
circular fin (1), which is extended from the shroud (2) inward toward
the hub (3), is to be inserted between the disks (4) completely or
partially off the disk periphery.

      Numerical simulation results indicate a significant
laminarization of the flow near the disk-edge region resulted from
the installment of this circular fin.

      The thickness of this fin should be preferably thin to
eliminate the generation of turbulence by the fin itself at its tip.

      Removing a fraction of the fin in its periphery is not expected
to have a significant impact on the effectiveness of the fin, as the
flow will be relaminarized over a small distance of the order of
several disk spacing (typically of several millimeters), which is
much smaller than the disk periphery (typically of several hundreds
of millimeters).

      Disclosed anonymously.