Archive: Dec 2022

Magnetic Levitation

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SMT Maglev train

Also known as magnetic suspension, magnetic levitation (maglev) occurs when magnetic fields suspend an object in the air, with magnetic force overcoming gravitational force to keep it aloft. The idea of magnetic levitation has been around since at least 1904 when Robert Goddard, an American inventor and professor, authored a paper based on magnetic levitation as a concept. Maglev transferred from theory to reality in the 1910s when Emile Bachelet, a French-born engineer living in America, filed patents for maglev technology. A half-century later, during the late 1960s, Gordon Danby and James Powell of Brookhaven National Laboratory filed a patent for a maglev train utilizing superconducting magnets to enhance magnetic field power. 

Whatever the application, there are two issues to consider for successful magnetic levitation. The first is the amount of upward force needed so that an object can defy gravity, and the other is the stability necessary to prevent neutralized lift through unexpected flipping or sliding. Maglev trains are among the most prominent uses of magnetic levitation, and they are capable of maintaining sufficient lifting force and stability for effective transportation.

How Do Maglev Trains Work?

A maglev train utilizes superconducting magnets set into each of a train car’s four corners, as well as a specialized track. A magnet becomes superconducting when its temperature reaches -450° F. This frigid temperature enables these magnets to produce magnetic fields with as much as 10 times the strength of the fields that regular electromagnets produce. It’s this capability that gives the maglev trains the ability to levitate and propel forward. The magnets located on a train car’s front two corners have their north poles facing out, with the back magnets positioned to have their south poles out.

As for the special track, or a guideway configured in a U-shape, it has metallic loops consisting of aluminum or other conductive metals dispersed along its concrete walls. These loops interact with the enhanced magnetic fields, generating an electric current that, in turn, creates an additional field. 

There are three loop varieties that engineers place strategically along the guideways. One type produces a magnetic field that causes a train to levitate approximately 5 inches above the track. The second helps to stabilize train cars horizontally. In both cases, the loops use the force of magnetic repulsion to ensure that the train stays in its appropriate position on the track. 

The last loop type is for propulsion, utilizing power from the alternating current as well as magnetic repulsion and attraction forces to move the train forward. When operators electrify the propulsion loops on the guideway, the resulting magnetic fields propel the train forward by pulling on the front magnets and pushing on the back. Magnets of matching poles repel when they face one another.

Benefits of Maglev Trains

Maglev trains offer an array of benefits to the transportation sector. These include:

  • Increased speed. High-speed maglev trains can achieve and maintain speeds of 375 mph safely.
  • Enhanced safety. These innovative trains rule out a number of the safety concerns inherent in traditional trains. For example, all maglev trains on the same track would have no risk of colliding because all the trains are moving at the same speed. Maglev trains also eliminate the chance of taking corners at sufficient speeds to derail, as magnetic forces only become stronger as the train moves from its standard positioning between the walls of its guideway and will effectively pull the train back.
  • Smooth movement. Air is the only factor providing friction, so despite the speed, passengers won’t feel the usual turbulence associated with train travel. Also, as these trains have minimal contact with their tracks, this reduces overall vibration.
  • Noise reduction. With minimized vibration comes the added benefit of reduced noise for passengers.
  • Decreased downtime. Maglev trains experience fewer breakdowns due to mechanical issues than standard trains, which makes sense given the reductions in friction and vibration.

Custom Coils: A Magnetics Industry Leader

Magnetic levitation trains have the capability to successfully and safely maintain lift and achieve propulsion through the force of superconducting magnets and magnetic fields. Given their cost to build, maglev train use is not widespread, but magnetic levitation is an innovative concept that has the potential to revolutionize rail travel. 

At Custom Coils, our team is committed to new ideas. We’ve been custom-designing and manufacturing magnetic components in the USA since 1967. For 55 years, we’ve continued to serve diverse industries ranging from transportation to communication and agriculture to aerospace with customer service that is second to none. Contact us today to experience the Custom Coils difference and learn more about our capabilities for innovative magnetic products.