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Head Suspension for Reducing Airflow Induced Vibrations

IP.com Disclosure Number: IPCOM000123650D
Original Publication Date: 1999-Feb-01
Included in the Prior Art Database: 2005-Apr-05
Document File: 2 page(s) / 63K

Publishing Venue

IBM

Related People

Palmer, DD: AUTHOR [+3]

Abstract

Abstract: Actuator head suspension vibrations in disk drives due to airflow induced excitation can cause significant deterioration in disk data access time and track mis-registration. Such vibrations can be significantly reduced by streamlining the cross section of the suspension load beam. Presented here are a variety of load beam cross-section designs which minimize air turbulence around head suspensions, thereby reducing flow induced vibrations and related side effects.

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Head Suspension for Reducing Airflow Induced Vibrations

   Abstract:

   Actuator head suspension vibrations in disk drives due to
airflow induced excitation can cause significant deterioration in
disk data access time and track mis-registration.  Such vibrations
can be significantly reduced by streamlining the cross section of
the suspension load beam.  Presented here are a variety of load beam
cross-section designs which minimize air turbulence around head
suspensions, thereby reducing flow induced vibrations and related
side effects.

   Description:

   Conventional suspension load beams are typically built with
two or more stiffening flanges, which are formed at an angle of
approximately 90 degrees to the airflow.  Calculations show that the
expected frequency of alternating vortex shredding at the outer disk
diameter is in the range of 1.5 to 1.9 Khz for typical high RPM disk
drives.  This frequency is close to the torsional frequencies of the
head suspension and can therefore be expected to excite these
frequencies during file operation.  Vortex shedding from the formed
stiffening flanges is also possible which can excite suspension modes
over an even wider frequency range.  Since airflow excitation is
known to be proportional to the square of the air velocity, such
excitation will be more severe for smaller sliders where the
suspension load beam is closer to the disk as well as high RPM
(>7200) files.  Reduction of all such vibration excitation can be
acc...