Browse Prior Art Database

Hard Disk Drive Comb Arm to Suspension Compliant Damped Joint for Improved Dynamics

IP.com Disclosure Number: IPCOM000117880D
Original Publication Date: 1996-Jul-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 2 page(s) / 55K

Publishing Venue

IBM

Related People

Lawson, DB: AUTHOR

Abstract

In hard drives, often low damped, in-plane arm modes couple with low damped suspension modes resulting in high amplitude modal peaks that reduce servo performance.

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This is the abbreviated version, containing approximately 82% of the total text.

Hard Disk Drive Comb Arm to Suspension Compliant Damped Joint for
Improved Dynamics

      In hard drives, often low damped, in-plane arm modes couple
with low damped suspension modes resulting in high amplitude modal
peaks that reduce servo performance.

      This invention consists of an arm/suspension (HSA) compliant
joint that increases damping and decreases coupling between comb arms
and suspensions that reduce the amplitudes of particular modes.  In
effect, many of the higher frequency transfer function modes are
filtered out.

      If the joint stiffness is reduced (more compliant) to a precise
value, the arm and HSA dynamic modes have reduced coupling.  This
results in an improved dynamic response over a local bandwidth.  The
joint compliance increases the local strain in the joint, which
allows the designer to increase modal damping by adding damping
material under shear strain.  The Figure shows a HSA connected to an
arm tip.  Section A-A shows the cross sectional detail of the swivel
joint.  Mount block (3) is swaged into the arm tip (2).  There is a
feature on the mount block that controls the spacing of the mount
block to the arm tip.  Section B-B shows between the mount block and
arm tip are two layers of visco elastic damping/adhesive material (4)
and the base of the load beam (1).  This assembly provides rotational
compliance about the z-axis and shear deformation in the damping
material (4).

      The area, thickness and dynamic m...