Browse Prior Art Database

Displacement Amplification

IP.com Disclosure Number: IPCOM000036880D
Original Publication Date: 1989-Nov-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

DeHillerin, CA: AUTHOR [+6]

Abstract

This displacement amplification method reduces the amount of torque that a spindle motor in a disk drive must provide directly to start the spindle. The method employs the excitation of one or more mechanical resonance(s) of the disk drive structure in such a manner as to cause increased displacement at the head-to-disk interface, breaking the heads loose from the disk and reducing the amount of torque required from the motor.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 1

Displacement Amplification

This displacement amplification method reduces the amount of torque that a spindle motor in a disk drive must provide directly to start the spindle. The method employs the excitation of one or more mechanical resonance(s) of the disk drive structure in such a manner as to cause increased displacement at the head-to-disk interface, breaking the heads loose from the disk and reducing the amount of torque required from the motor.

Electrical pulses at or close to the desired resonance frequencies are supplied to the spindle motor which converts the electrical pulses into mechanical pulses, exciting the resonance(s). The pulses cause the spindle to rotate back and forth. They can be provided at the desired frequency in an uncontrolled manner, or the spindle can be instrumented and the system driven only when the spindle is going in the desired direction.

The resonance(s) are any one of many in the disk drive structure, including but not limited to the base casting or frame, the disk pack/ head suspension spring/inertia system, the spindle bending, or the actuator structure. In addition, an error reporting scheme is incorporated into the system if this procedure is used only as a backup to a normal motor-starting routine. The reporting scheme allows tracking of stiction levels encountered. This is used to alert a field representative for replacement and/or to facilitate field failure analysis.

1