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Browse Prior Art Database

Thermal Distortion Reducing Bar for a Linear Actuator

IP.com Disclosure Number: IPCOM000110736D
Original Publication Date: 1992-Dec-01
Included in the Prior Art Database: 2005-Mar-25
Document File: 1 page(s) / 60K

Publishing Venue

IBM

Related People

Crawforth, L: AUTHOR [+3]

Abstract

Disclosed is a method to reduce thermally induced distortion in the linear actuator of a hard disk drive. This method results in decreased TMR (Track MisRegistration) and therefore better performance of the drive.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 76% of the total text.

Thermal Distortion Reducing Bar for a Linear Actuator

      Disclosed is a method to reduce thermally induced distortion in
the linear actuator of a hard disk drive.  This method results in
decreased TMR (Track MisRegistration) and therefore better
performance of the drive.

      High Performance hard disk drives typically suffer from
thermally induced TMR, which can limit track density and therefore
storage capacity.  This thermally induced TMR typically occurs due to
cold start or ambient temperature changes.  It is caused by
distortions of the drive components due to differences in the CTE
(Coefficient of Thermal Expansion) of materials used.  Due to other
engineering requirements, these CTE differences are often
unavoidable.

      The design disclosed here reduces thermally induced bow in the
rail of a linear actuator.  The carriage moves the read/write head
rolls on this rail, so bow of the rail induces thermal TMR.  The
design consists of a simple compensating bar placed on the rail
support system to counteract the forces which cause the rail to bow
during temperature changes (see Figure).

      For this application, aluminum 2024 was selected for low cost
and appropriate CTE.  Finite element analysis was used to study the
effect of geometry and connection points on the distortion.  By
iteration a near optimal design was generated.  Holography testing on
prototype parts verified that the design successfully reduced the
rail bow close to zer...