in electric motors provide a good example of how adhesives can be used for
brittle substrates and are typically assembled by applying adhesives. While
mechanical fasteners create focused stress points, adhesives disperse the
stress over the entire bonded area. There are different types of adhesives for
magnet bonding applications that can achieve a bond strength higher than the
magnet tensile strength. These adhesives are selected according to the need of
the application area. The performance criteria differentiating these adhesive
types are typically the curing time, temperature resistance, fixture speed, gap
fill and impact strength.
assemble magnet segments in electric motors, Hernon recommends React®
727 because it produces a strong bond very quickly while maintaining strong
vibration resistance. React® 727 is recommended for bonding magnets
to housings but it can also bond magnet segments or ring magnets to rotors. The
primary benefits of this adhesive choice are the speed of curing and ease of
use. Simply apply a small amount on a clean dry surface of the magnet and hold
against the second substrate for 30-60 seconds. Hernon’s Activator 63 can be
used to further enhance fixture time.
common adhesive application in electric motors is retaining bearings and
cylindrical parts. Assemblies of cylindrical or spherical parts, such as
rotors, gears, bushings, collars and bearings, can be accomplished with Hernon
retaining compounds. The recommended grades of Hernon retaining compounds are
Cylinlock 822 and Cylinlock 846. These compounds are high strength anaerobic
liquids that cure to a tough plastic when air is excluded. These adhesives
prevent corrosion, eliminate warping of the shaft and provide maximum contact between
mating surfaces when cured.
is another application for adhesive materials in electric motors. Threadlocking
adhesives work by filling voids between the threads on screws, nuts and bolts.
This process provides a high strength bond to supplement the natural holding
power of the assembly. Threadlockers are anaerobic adhesives, so they cure in
the absence of oxygen between close fitting metal surfaces. Once cured,
threadlockers have excellent moisture, temperature and chemical resistance
allowing them to help seal and prevent corrosion of metal parts while also
resisting vibration and the loosening of threaded assemblies.
family of threadlockers is called Nuts N’ Bolts. Nuts N’ Bolts grades 423 and
425 are two of Hernon’s threadlockers recommended for use in electric motors. Grade
423 cures quickly to produce a resilient seal with predictable torque values.
This grade is also suitable for less active metals like stainless steel and
plated metals. For a higher strength bond when using fasteners up to 1 inch in diameter
grade 425 is suggested. It is tolerant of harsh and corrosive environments and designed
to support heavy-duty applications such as studs into motor housings. Both
adhesives have characteristic colors (blue for 423 to show medium strength and
red for 425 to show high strength) that help when monitoring the application of
the product during service.
working with fasteners over 1’’ in diameter, Nuts N’ Bolts 429 is the ideal
formula to use. However, if your task includes preassembled equipment and
structures where penetration into fastener connection points is required, Nuts
N’ Bolts 431 offers the required wicking properties. Wicking products allow
thread locking without dismantling equipment. A wide selection of Nuts N’ Bolts
grades are available to provide specialized characteristics and meet varying performance
requirements. Formula properties such as viscosity, shear strength, maximum gap
filling, colors and cure time can be matched to meet specific needs.
areas of electric motors such as flanges and housings will need to be sealed
with a gasket to ensure leak proof operation. A gasket is a mechanical seal
that fills the space between two or more mating surfaces to prevent leakage. Hernon’s
Gasketing compounds are formulated to provide instant sealing capabilities and
excellent chemical resistance. Gasketing sealants offer benefits such as easy
application, a precise match to unique shapes and lower costs over their pre-formed
alternatives. Gasketing compounds are commonly anaerobic or silicone based.
Common applications include sealing the junction box with both motor stator and
lid as well as the bell housing to the motor stator.
sealing an area of the motor such as the junction box, Gasket Replacer 910 is
recommended. Gasket Replacer 910 is an anaerobic compound formulated to provide
instant sealing capabilities, a reliable long-term seal and excellent chemical
resistance. For sealing bell housing to motor stator, Hernon®
recommends Silastomer 343. Silastomer 343 is a silicone-based Gasket Compound
with a paste-like consistency which cures to a durable silicone rubber when
exposed to moisture in the air. Silastomer 343 is suitable for metal, glass,
wood, plastic and ceramic surfaces. 343 offers very high resistance to moisture
and temperature and remains highly flexible.
when bonding plastic components and rubber tubing, cyanoacrylate adhesives are suggested.
Hernon specifically recommends Quantum 135 with near instant set time and a
high resistance to humidity. Quantum 135 is a very stable product with ≥ 2000
PSI shear strength. Quantum 135 is designed to seal plastic to metal on the
shaft exit and it can also be used to produce fast bonds on the name plates and
other non-structural pieces.
can learn more about Hernon products by watching the videos at Hernon’s You
Tube account here: https://www.youtube.com/watch?v=EjgAAP3z47Y.
To request a sample of adhesives for testing please contact Hernon’s team via
the company website at: https://www.hernon.com/request-an-adhesive-sample/.