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Interposing Viscoelastic Dampeners between Motor Laminations

IP.com Disclosure Number: IPCOM000115217D
Original Publication Date: 1995-Mar-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 2 page(s) / 50K

Publishing Venue

IBM

Related People

Boutaghou, ZE: AUTHOR

Abstract

Disclosed is a method to reduce motor vibrations from being transmitted to the spindle shaft, and increasing motor efficiency is achieved by interposing viscoelastic dampeners between laminations to reduce bending and torsion of the laminations, to decouple the laminations from each other, and to reduce eddy currents.

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Interposing Viscoelastic Dampeners between Motor Laminations

      Disclosed is a method to reduce motor vibrations from being
transmitted to the spindle shaft, and increasing motor efficiency is
achieved by interposing viscoelastic dampeners between laminations to
reduce bending and torsion of the laminations, to decouple the
laminations from each other, and to reduce eddy currents.

      By interposing a dampening material between the laminations,
the amplitude of vibration of the laminations will be greatly
reduced.  The advantage of interposing dampening material between the
laminations spatially decouples the laminations yielding lower eddy
current losses.  The reduction in eddy current losses and hysteresis
losses will greatly improve the efficiency of the motor.

      The motor efficiency of 3.5-inch motors is around 60-70%.  The
efficiency of 1.8-inch motors is around 40-50%.  As the size of the
motor is reduced, the motor efficiency is reduced as well.  The
decoupling of the laminations will greatly reduce both the eddy
current losses yielding a more efficient motor.  The increase in
efficiency is very much desired even for 3.5-inch spindles to reduce
the run current for the future high-speed applications.

      The major impact is an increase in height of the motor.  For
example, a motor with 10 laminations of 0.5 mm each will require an
increase in thickness 0.025 times 9 = 0.25 mm which is about 4%.  The
required height increase in the...