3M Advanced Materials Division
Introduction
In the wind energy sector,
as in many other industries,
economic and technical factors
are driving the following trends
in component requirements:
• Higher power density: Increasing
loads with reduced weight
and constructed space
• Ease of installation
• Long life and maintenance-
free operation
• Reliability and safety
• Cost efficiency
To transfer higher loads in friction
joints such as flanges or shaft-collar
connections, the size or number of
components or fasteners generally
must be increased; this in turn impacts
negatively on the size, weight and
costs of the overall system. Instead
of increasing component size,
3M friction shim technology can
be used to increase the coefficient
of friction between components.
Advantages
3M friction shims increase the
friction at the joining surface
of two components up to a
factor of 4, thereby expanding
design freedom for individual
components or the entire system.
3M friction shims offer a simple
yet effective solution for the
following requirements:
• Increase of transmittable forces
and torques of a connection
• Reduction of component
sizes and weights
• Consequential weight reduction
of adjacent components
and the overall system
• Greater margin of safety
• Cost reduction of individual
components
• Ease of use
• Insensitivity to lubricants
• Reusability after disassembly
• Application without requiring
significant design changes
3M
™
Friction Shims for
Wind Energy Applications
Figure 2. Contact surface of friction joint with
3M
™
Friction Shim after assembly and disassembly
3M
™
Friction Shims provide a reliable solution to increase the coefficient of friction in
bolted or shaft-collar connections. They enable higher potential loads and torque rates
with a compact and lightweight design.
Typical Coefficient
of Friction
(Not for specification purposes)
Figure 3. Results of a series of tests on
the coefficient of static friction with and
without 3M
™
Friction Shims. The shaded
areas of the bar show the variation.
0.1 0.2 0.3 0.4 0.5 0.6 0.7
0.8
EN-GJS700 / EN-GJS700
with 3M
™
Friction Shims
0.0
EN-GJS700 / S690QL
with 3M
™
Friction Shims
EN-GJS700 / 18CrNiMo7-6
with 3M
™
Friction Shims
EN-GJS700 /
S690QL
Counterpart 1
Counterpart 2
Steel Foil
Nickel
Matrix
Diamond
Microgap
3M
™
Friction Shim Diagram
Figure 1. Tribosystem with 3M
™
Friction Shim.
Functional Principle
The functionality of 3M
™
Friction
Shims is the result of diamond particles
with defined size and distribution
protruding from a nickel coating. The
coating is applied on thin steel foils.
During assembly of the components,
the diamonds penetrate the counter
surfaces and create a micro-scale
interlock. This method allows higher
loads to be transmitted through
the connection in a reliable and
reproducible way. The resulting
coefficient of static friction can reach a
value of 0.6 or even higher, depending
on the application parameters.
Handling Instructions
• Store 3M friction shims only
in original packaging.
• Don’t handle 3M friction shims
as bulk unless a clip variant is
used that has been specifically
designed for bulk storage.
• Don’t expose 3M friction shims
to temperatures above 400°C.
• Avoid contact of 3M friction shims
with corrosive substances unless a
stainless steel substrate is used.
• Don’t bend 3M friction shims.
• No mechanical treatment
of 3M friction shims.
• Before assembling 3M friction shims,
make sure no dirt residue is present.
• Ensure a minimum contact
pressure of 50 MPa.
• Check correct quantity
during assembly.
• Avoid relative movement of shims
on surface when disassembling.
• 3M Technical Ceramics offers
support in defining a suitable
assembly concept.
Applications
Typical wind energy applications include
flanges and other connections in the
powertrain, bolted connections on the
bed plate, and the fasteners of bearings,
brakes and other components.
The
manufacturing process is certified
according to ISO TS 16949 and
therefore meets stringent requirements
for automotive applications. To date,
3M friction shims have been used
millions of times by the automotive
and various other industries.
3M friction shims have also been
certified by Germanischer Lloyd for
various material combinations and
application parameters, making
them versatile solutions for use
in the wind energy sector.
3M is a trademark of 3M Company.
Used under license by 3M subsidiaries
and affiliates.
Please recycle. Printed in USA © 3M 2016.
All rights reserved. Issued: 6/17 12719HB
98-0050-0044-9 Rev. C
3M Technical Ceramics
Zweigniederlassung der 3M Deutschland GmbH
Max-Schaidhauf-Str. 25, 87437 Kempten, Germany
Phone +49 (0)831 5618-0
Web www.3M.de/Technical-Ceramics
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3M Advanced Materials Division
3M Center
St. Paul, MN 55144 USA
Phone 1-800-367-8905
Web www.3M.com/frictionshims
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