Browse Prior Art Database

Enhancement to Conductive Magnetic Fluid Seals

IP.com Disclosure Number: IPCOM000122248D
Original Publication Date: 1991-Nov-01
Included in the Prior Art Database: 2005-Apr-04
Document File: 2 page(s) / 57K

Publishing Venue

IBM

Related People

Benson, GA: AUTHOR

Abstract

A method for lowering the dynamic impedance of conductive magnetic fluid seal by approximately one order of magnitude is disclosed.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 87% of the total text.

Enhancement to Conductive Magnetic Fluid Seals

      A method for lowering the dynamic impedance of conductive
magnetic fluid seal by approximately one order of magnitude is
disclosed.

      It has been demonstrated that if strands of a soft magnetic
material (such as 4xx series stainless steel) with length dimensions
slightly longer than the clearance between inner and outer poles
(denoted as "g" in Fig. 1) of a conductive magnetic fluid seal are
introduced to the seal fluid, the impedance of the seal drops by
approximately one order of magnitude.

      Fig. 2 shows the resultant orientation of free strands of
material introduced to the seal after allowing the seal to rotate.
This orientation is due to both the magnetic field within the seal
and the dynamic forces caused by rotation.  A more likely
implementation of this invention would be to fix the strands within
the seal, along axis Y-Y in Fig. 1, with the same orientation as
shown in Fig. 2.  This will minimize any tendency for splashing of
the magnetic fluid.

      While extremely low impedances appear impossible with this
invention due to the boundary layer film of magnetic fluid existing
between the strands and the pole faces, an important feature is
preserved by this condition.  The wear rate of the strands will be
minimal as a result of the film's lubrication properties and thus
long life is expected.

      Extending the above observations, it should be possible to use
a non-conductive m...