Turbomachinery Coupling Catalog - Emerson Industrial Automation

The Flexible Disc Pack
The Flexible Disc Pack is the heart of the Kop-
Flex High Performance coupling and transmits
torque while accommodating axial, offset and
angular misalignment.
The Flexible Disc Pack is a series of precision
manufactured discs assembled with washers
and bushings into a unitized pack. The disc
material is special, high strength, 301 stainless
steel and each disc is Koplon* coated to
help prevent fretting corrosion. Alternate
disc materials, such as Inconel, are available;
consult Kop-Flex.
The discs have a “waisted” or “scalloped” link
design. This results in increased flexibility
and subsequent lower reaction forces on
the connected equipment bearings. Further,
stress distribution is uniform, which allows for
increased misalignment capability and lower
fatigue stresses on the discs. The scalloping
also reduces weight and inertia.
The discs are designed for infinite life with a
factor of safety. Under loading, the disc pack
is exposed to constant stresses due to torque,
centrifugal force, axial misalignment and
pretension, and to alternating stresses due to
angular and offset misalignment.
The combined effect of these stresses is plotted
on a modified Goodman diagram, which gives
the disc material endurance limit boundaries.
Generally, at normal operating conditions, and
at maximum angular misalignment and axial
displacement ratings, the discs operate with
a nominal safety factor of 2.
*Koplon is a Teflon based (PTFE) material of proprietary formulation.
*Koplon and Teflon are trademarks and/or trade names of E. I. du Pont de Nemours and Company.
These trade names, trademarks and/or registered trademarks of others are used herein for product comparison purposes only, are the property of their respective owners and are not
owned or controlled by Emerson Power Transmission Corporation. Emerson Power Transmission does not represent or warrant the accuracy of this document.
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