Magnetic Bearing FAQ

Answers to typical AMB technology questions.
Magnetic bearings, high-speed motors and generators and power conversion systems have all changed a great deal over the years. And Synchrony® innovation has played a major role in advancing this technology. Learn more about the technology and find answers to questions about using magnetic bearings in your applications.

What happens in the case of a Loss of power?

In the event of a loss of power, Synchrony recommends the use of an uninterruptable power supply (battery back up), which will allow sufficient time for a controlled coast down. Additionally, each Synchrony AMB system contains auxiliary bearings to further protect the machine.

Is this technology brand new?

The basic principles of electromagnetism have been applied to motors and generators since the late 19th century, and the principles of magnetic levitation were demonstrated in the 1940s. What has changed is the increased stability, miniaturization, simplification, and cost-effectiveness of magnetic bearings, so they can be used in a wide variety of high-performance motors, generators, turbomachines and more. Recent advances have allowed magnetic bearing technology to be taken out of the laboratory and applied to wide variety of rotating equipment.

Are active magnetic bearings (AMB) very complicated?

Although the electronic hardware and the control algorithms to control the rotor are complicated, these are virtually invisible to the user, in much the same way that a cell phone is complex, yet easy to use.

Aren't magnetic bearing controllers and electronics large and cumbersome?

This has been true in the past, but is no longer the case. Synchrony's magnetic bearings use compact controllers, that are so small and simple they can be mounted either on or near the machine.

Does the tuning of AMBs require an engineering specialist with an advanced degree? How long does tuning and optimizing take?

It once took many days to levitate the rotor, and weeks to optimize AMB performance. But Synchrony has significantly reduced the time required for these operations, using powerful tools to measure the stability of the magnetic bearing system, and to optimize control parameters. As a result, optimization of the magnetic bearing system often takes hours, not weeks. Synchrony can often perform optimization remotely.

Does final tuning of AMB have to be done in the field?

A new machine will require optimization under prototypical operating conditions to ensure high performance. However, identical machines will require no field tuning.

How hard is it to connect AMBs to a controller?

There are sensor and power leads to connect to the controller. NovaGlide® magnetic bearing systems can be preconfigured with proper cable length and connectors, simplifying the installation.

Is it difficult to interpret the information from AMBs?

Not any longer – Synchrony provides software that can display information graphically through a graphical user interface and simplifies the interpretation and readability of the data. Vibration, force, and temperature data can all be graphically displayed.

What happens if the AMBs of a rotating machine is overloaded - must the bearings be restarted to gain control?

Synchrony’s algorithms maintain stability even if the magnetic bearing capacity is exceeded through high static or dynamic loads caused by surge, stall, mechanical shock, or other transients. The software algorithm recognizes this condition and automatically compensates to ensure that once the condition has passed, the controller immediately and stably centers the rotor and normal operation continues. No restart is required.

Read more about why you should use magnetic bearings or find out how we can help with your next application.

Related Links

White Paper - Improving Rotating Machinery Performance with Dresser-Rand's Synchrony® Active Magnetic Bearings (387 KB PDF)
Learn More About Synchrony

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