Browse Prior Art Database

In-Hub Filter

IP.com Disclosure Number: IPCOM000102098D
Original Publication Date: 1990-Oct-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 2 page(s) / 63K

Publishing Venue

IBM

Related People

Greaves, HR: AUTHOR [+2]

Abstract

An air filtration scheme is disclosed to protect disk and head surfaces in magnetic disk files from contamination by particles or aerosols, specifically from motor bearing lubricants. The simple embodiment described is a sealed Head Disk Assembly (HDA) with several hard disks mounted on a hub driven by a motor fitted centrally inside the hub.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 68% of the total text.

In-Hub Filter

       An air filtration scheme is disclosed to protect disk and
head surfaces in magnetic disk files from contamination by particles
or aerosols, specifically from motor bearing lubricants.  The simple
embodiment described is a sealed Head Disk Assembly (HDA) with
several hard disks mounted on a hub driven by a motor fitted
centrally inside the hub.

      Fig. 1 shows typical air flow circulation in an enclosed HDA 1
with a central hub 2 mounting several disks 3 (only six shown) and
driven by an internal electric motor 4. Actuator 5 laterally
positions read/write heads 6 on each side of disks 3. Air passage 8
exists between the disks 3 and hub 2 via ducted spacer rings 7.  Air
is fed from the main air filter 9 to the top of hub 2 and
passes through clamp ring holes 10 down the outside  of the hub
exhausting through ducts in the spacer rings 7 and across the
surfaces of disks 3.  It continues past the heads 6 and the actuator
mechanism 5 returning with any contaminants back into the main filter
9.  This arrangement produces an air pressure drop between the top
and bottom of the hub 2 causing a secondary air flow through the
bearings 13 dragging particles of bearing grease into the main air
flow from which it can contaminate the heads and disks via the clamp
ducts 10.

      A solution shown in Fig. 2 is to provide a tubular high
efficiency filter 12 which fits inside the clearance space sealing
off at the top 11 and the bottom of the hub 2.

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