A permanent magnet may be the heart of a magnetic system, but sometimes the magnet alone is not enough. Magnetic assemblies combine one or more magnets with components such as steel housings, brackets, pole pieces, or other materials to create a more complete solution for a specific application. A properly designed assembly can offer advantages beyond simply choosing a larger or stronger magnet.

Depending on the design, an assembly might include:

  • Neodymium, samarium cobalt, ceramic, or alnico magnets
  • Steel cups, channels, back plates, or pole pieces
  • Threaded studs or mounting hardware
  • Protective coatings or housings
  • Multiple magnets arranged in a specific orientation

Why Use an Assembly Instead of a Standalone Magnet?

Improve Holding Performance

Steel components, such as those in channel- and cup-style mounting magnets, can channel and focus magnetic flux directly onto a working area.

That said, incorporating steel does not guarantee a predetermined gain in holding capacity. Actual performance hinges on several factors, including the magnetic circuit as a whole, magnet geometry, temperature, mating surface characteristics, air gaps, and the material and thickness of the steel.

Additionally, published pull force ratings reflect ideal testing environments. In practical applications, factors like thin steel substrates, surface coatings, gaps, shear stresses, or uneven contact can substantially alter actual holding power.

Protect the Magnet

High-strength rare earth magnets are powerful, but brittle. A surrounding cup, channel, or housing can provide additional physical protection in applications where an exposed magnet could experience impacts or repeated handling.

Appropriate coating and housing materials must be considered when moisture, chemicals, heat, or other environmental conditions are present.

Simplify Installation

Sometimes the biggest advantage is mechanical.

An integrated stud, threaded hole, countersunk opening, bracket, or other mounting feature can make the finished component easier to incorporate into equipment.

For production environments, sourcing a completed assembly may also reduce the number of separate components that need to be handled and installed during final manufacturing.

Industries that Use Magnetic Assemblies

Motors and Transportation

Permanent magnets can form part of the rotor assembly in certain electric motor designs. The U.S. Department of Energy notes that permanent magnet motors use a rotor containing a series of magnets and are widely used in electric drive applications.

Sensors and Automation

Many automated systems use magnet-and-sensor combinations for position, speed, proximity, and motion detection.

The magnet's location and orientation can be critical because the sensor needs to detect a predictable magnetic field. NIST notes that magnetic sensors span industrial, electronics, transportation, biomedical, infrastructure, and other applications.

Renewable Energy

Permanent magnets also play a role in certain wind turbine generator designs. Direct drive permanent magnet generators use large arrangements of magnets that rotate with the rotor to generate electricity as they pass stationary coils.

However, not all wind turbines use permanent magnet generators. Generator architecture varies considerably across the industry.

What Should Engineers Consider When Designing an Assembly?

Selecting the magnet material and grade is only one part of the process. Engineers should consider the entire operating environment and how the component will interact with the rest of the system.

  • What field strength, holding force, torque, or sensing result does the application require?
  • How much space is available?
  • What is the operating temperature range?
  • Will the component encounter moisture, chemicals, vibration, or impact?
  • How will the assembly be mounted?
  • What direction should the magnetic field face?
  • Are tight dimensional tolerances required?
  • Will the design need to scale from prototype to production?

Answering these questions early can help determine whether a stocked magnet or existing mounting solution will work or whether the application calls for a custom design.

When Does a Custom Magnetic Assembly Make Sense?

Custom magnetic assemblies are particularly useful when the magnet must work within specific mechanical, environmental, or magnetic constraints.

An engineer might consider customization when a standard product cannot provide the required geometry, magnetization direction, mounting method, operating temperature, field characteristics, or integration with surrounding components.

Customization can also make sense when combining several individual parts into a finished component could simplify production.

Finding the Right Magnetic Solution

Choosing a magnet is often only the beginning. How the magnet interacts with steel components, mounting hardware, nearby materials, operating temperatures, and the rest of the system can influence the final result just as much.

Apex Magnets works with businesses to help identify standard and custom magnetic solutions based on application requirements. With years of magnet experience, a fully stocked U.S. warehouse, fast processing and shipping, and personal guidance, our team can help you determine whether an in-stock product meets your needs or a custom solution makes more sense.

Contact Apex Magnets to discuss your application or request information about a custom order.

 

Safety Warning: Children should not be allowed to play with neodymium magnets as they can be dangerous. Small magnets pose a choking hazard and should never be swallowed or inserted into any part of the body.

Magnets can be dangerous. Neodymium magnets, especially, must be handled with care to avoid personal injury and damage to the magnets. Fingers and other body parts can get severely pinched between two attracting magnets. Bones can be broken by larger magnets. Visit our Magnet Safety page to learn more.