Design Guide
Assembly
Considerations
Integrated
Magnetics Inc. has manufacturing capabilities to manufacture
complex magnet pole pieces and housings to provide a
complete magnet assembly. The following points should
be considered when designing magnet assemblies.
Affixing
Magnets to Housings
Magnets
can be successfully affixed to housings using adhesives.
Cyanoacrylate adhesives that are rated to temperatures
up to 350 F
with fast cure times are most commonly used. Fast cure
times avoid the need for fixtures to hold the magnets
in place while the bond cures. Adhesives with higher
temperature ratings are also available, but these require
oven curing, and fixturing of the magnets to hold them
in place. If magnet assemblies are to be used in a vacuum,
potential out-gassing of the adhesives should be considered.
Housing
Design
Integrated
Magnetics is equipped with state of the art CNC and
EDM equipment allowing the manufacture of complex housings.
Effective magnet locating sections should be included
in housing designs to support and locate magnets precisely.
Mechanical
Fastening
When
arrays of magnets must be assembled, especially when
the magnets must be placed in repelling positions, it
is very important to consider safety issues. Modern
magnet materials such as the Rare Earths are extremely
powerful, and when in repulsion they can behave as projectiles
if adhesives were to break down. We strongly recommend
that in these situations mechanical fastening be included
in the design in addition to adhesives. Potential methods
of mechanical retention include encasement, pinning,
or strapping the magnets in place with non-magnetic
metal components. The Design Engineering team at Integrated
Magnetics is experienced in magnet housing and fastening
designs, and we will be pleased to assist in arriving
at an appropriate design.
Potting
Magnet
assemblies may be potted to fill gaps or to cover entire
arrays of magnets. Potting compounds cure to hard and
durable finishes, and are available to resist a variety
of environments, such as elevated temperatures, water
flow, etc. When cured, the potting compounds may be
machined to provide accurate finished parts.
Welding
Assemblies
that are required to be hermetically sealed can be welded
using either laser welding (which is not affected by
the presence of magnetic fields) or TIG welding (using
appropriate shunting elements to reduce the effect of
magnetic fields on the weld arc). Special care should
be taken when welding magnetic assemblies so that heat
dissipation of the weld does not affect the magnets.
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