Browse Prior Art Database

Dual Seal for High Speed and High Temperature Disk Drives

IP.com Disclosure Number: IPCOM000113703D
Original Publication Date: 1994-Sep-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 80K

Publishing Venue

IBM

Related People

Boutaghou, ZE: AUTHOR

Abstract

A dual seal design combining a magnetic fluid seal design with a labyrinth seal design is described to extend the life of the ball bearings and keep the file contaminant free.

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Dual Seal for High Speed and High Temperature Disk Drives

      A dual seal design combining a magnetic fluid seal design with
a labyrinth seal design is described to extend the life of the ball
bearings and keep the file contaminant free.

      Magnetic Fluid Seals - The primary function of the magnetic
fluid seal is sealing to avoid airflow through the bearings.  This
function is extremely important and necessary to insure extended life
required for high speed applications.  The magnetic fluid design at
high speeds and high temperature presents considerable challenges to
the spindle community.  The challenges include spin-out, evaporation,
and conductivity of the magnetic fluid.

      Spin-out - The retention improvement of the magnetic fluid
under high centrifugal forces can be achieved by decreasing the fill
volume and increasing the viscosity of the fluid.

      Evaporation - High viscosity fluids are desirable to decrease
the evaporation of the magnetic fluid at high temperatures.

      Conductivity - It is desirable for the magnetic fluid seal to
provide additional grounding function to avoid electro-static
discharge damage to the magnetic heads.

      The labyrinth seal minimizes the flow through the bearings but
it does not stop the flow completely.  The labyrinth seal does not
provide any grounding.

      Dual Seal Design - This disclosure proposes to use an integral
magnetic fluid seal and a labyrinth seal to prolong the life of ball
bea...