Browse Prior Art Database

Magnetic Recording Head Flyheight Control Using Gas Jet

IP.com Disclosure Number: IPCOM000102981D
Original Publication Date: 1990-Apr-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 1 page(s) / 49K

Publishing Venue

IBM

Related People

Annis, JW: AUTHOR [+2]

Abstract

A method provides a capability to quickly change a flyheight of a R/W head in a direct access storage device (DASD) via a small diameter gas jet. This is in marked contrast to changing flyheight through a mechanical means. The method addresses the problem of applying a normal load to a slider or slider suspension without mechanical contact.

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Magnetic Recording Head Flyheight Control Using Gas Jet

      A method provides a capability to quickly change a flyheight of
a R/W head in a direct access storage device (DASD) via a small
diameter gas jet.  This is in marked contrast to changing flyheight
through a mechanical means.  The method addresses the problem of
applying a normal load to a slider or slider suspension without
mechanical contact.

      A small diameter gas jet having a velocity so as to produce a
force by a change in gas momentum at impact is used.  The applied
force is not very sensitive to small changes in the separation
between a nozzle producing the jet and a surface onto which the jet
is directed.  The applied force is primarily controlled by the jet
diameter and the average jet velocity.  The nozzle is positioned very
close to the surface so as to minimize the pressure fluctuations seen
at the surface due to jet turbulence.

      In the figure, an arrangement used for testing the gas jet
apparatus is shown.  A converging nozzle 4 with a small exit diameter
is supplied with pressurized nitrogen gas via a gas delivery tube 2.
The separation between the nozzle exit and the surface of a head 8 or
a suspension 6 is on the order of 2 to 3 nozzle diameters.  The force
produced by the jet is checked prior to testing by using a spring
force gauge.  The change in the head flying height at the gap is
monitored using a Harmonic Ratio Flyheight (HRF) Analyzer which
produces a voltage p...