Browse Prior Art Database

Adaptive Voice Coil Motor Coil Position for Actuator Imbalance Improvement

IP.com Disclosure Number: IPCOM000119150D
Original Publication Date: 1997-Dec-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 2 page(s) / 33K

Publishing Venue

IBM

Related People

Ohta, M: AUTHOR [+3]

Abstract

Disclosed is an improved design for an actuator carriage to be used in a hard disk drive. This design employs a metal carriage and a coil which are bonded together by adhesive. The improved actuator design described below pre-determines the weight of each coil, and accuracy varies the coil bonding position in the direction of the arm for assembly. This results in a more precise location for the center of mass for this sub-assembly.

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Adaptive Voice Coil Motor Coil Position for Actuator Imbalance Improvement

      Disclosed is an improved design for an actuator carriage to be
used in a hard disk drive.  This design employs a metal carriage and
a coil which are bonded together by adhesive.  The improved actuator
design described below pre-determines the weight of each coil, and
accuracy varies the coil bonding position in the direction of the arm
for assembly.  This results in a more precise location for the center
of mass for this sub-assembly.

      Actuator imbalance affects the head positioning performance in
a hard disk drive although the diameter control of the coil wire is
very good.  The tolerance for this parameter causes the coil mass
variance to  be the dominate contributor to the actuator assembly
imbalance variance.  Manufacture errors in the exact count for the
number of turns in the coil is another source mass variance for this
component.

Imbalance may be calculated as follows:
       Imbalance'  =  'Weight' X ' Length'
       Weight:  Weight of component
       Length:  Radii length from component center of gravity
                 to actuator rotational center.

      Another manufacturing process can rapidly weigh, sort, and
separate coil parts into mass categories, such as low/ nominal/ high
or low low / low / nominal / high / high high.  The required length
for each weight category can be calculated for a special balance, and
th...