Browse Prior Art Database

Start Up Assist by Resonant Actuator Displacement

IP.com Disclosure Number: IPCOM000121812D
Original Publication Date: 1991-Sep-01
Included in the Prior Art Database: 2005-Apr-03
Document File: 1 page(s) / 56K

Publishing Venue

IBM

Related People

Keller, CG: AUTHOR [+2]

Abstract

Disclosed is a start routine for rigid magnetic disk drives. Due to contamination, low texture or excess lubricant on the disks, several head disk interfaces in a file can be "stuck" prior to power-on. The motor torque available for start-up may not be able to overcome the buildup of stiction. Especially when considering that with the decreasing size of hard disk drives and spindle motors, the available torque for overcoming stiction is decreasing dramatically. By using this invention when the file is "stuck," the file will be able to start in many of the cases where the products spindle motor will not be able to start the magnetic disk drive unassisted.

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This is the abbreviated version, containing approximately 66% of the total text.

Start Up Assist by Resonant Actuator Displacement

      Disclosed is a start routine for rigid magnetic disk drives.
Due to contamination, low texture or excess lubricant on the disks,
several head disk interfaces in a file can be "stuck" prior to
power-on.  The motor torque available for start-up may not be able to
overcome the buildup of stiction. Especially when considering that
with the decreasing size of hard disk drives and spindle motors, the
available torque for overcoming stiction is decreasing dramatically.
By using this invention when the file is "stuck," the file will be
able to start in many of the cases where the products spindle motor
will not be able to start the magnetic disk drive unassisted.

      The disclosed start procedure uses the dynamics of the actuator
and head suspension assembly to decrease the amount of torque
required to start the motor.  The invention is implemented by
supplying current pulses to the motor at a frequency corresponding to
the resonant frequency of the actuator, suspension system.  The
system that is being resonated consists of a rotary inertia, the
actuator, a spring, and the suspension, which is rigidly attached to
the actuator by mechanical means and also stuck to the disk by the
stiction force.  In addition, there could be a second spring in the
system.  This spring would be the crash stop where the actuator is
typically held when the file is powered off.

      The resonant motion of the actuator overcome...