Browse Prior Art Database

A Sealed Disk Drive with Optimal Filtration Characteristics

IP.com Disclosure Number: IPCOM000108399D
Original Publication Date: 1992-May-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 1 page(s) / 47K

Publishing Venue

IBM

Related People

Tzeng, HM: AUTHOR

Abstract

This disclosure describes an optimal filtration scheme for disk drives that conforms to standard form factors. This scheme employs two particulate filters to remove optimally particles in the sub- and supermicron ranges in disk drives.

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This is the abbreviated version, containing approximately 94% of the total text.

A Sealed Disk Drive with Optimal Filtration Characteristics

      This disclosure describes an optimal filtration scheme for disk
drives that conforms to standard form factors.  This scheme employs
two particulate filters to remove optimally particles in the sub- and
supermicron ranges in disk drives.

      Supermicron-sized particles, generated at the head/disk
interface, are dominated by their inertia and tend to move in
tangential direction as indicated in the accompanying figure.  In
order to collect effectively supermicron-sized particles, a
low-impedance filter is to be located at a corner immediately
downstream of the arm/slider assembly.

      The filtration efficiency of airborne submicron-sized particles
can be determined from particle purge rate measurements.  Results
obtained by a noninvasive, laser-Doppleranemometry-based system
reveal a fine filter is most efficient when placed at the corner
immediately upstream of the arm/slider assembly (shown in the figure
as location A).  This optimal condition arises due to the 'pushing'
by the stalled flow upstream of the arm/slider assembly and the
'pulling' of the entrainment by the rotating disks.

      Since the sealed disk drive conforming to standard form factors
is practically in geometric similitude, the flow inside the drive,
hence the associated filtration flow characteristics, will also be
similar.  Therefore, the filtration scheme stated in this disclosure
represents an optimal one for...