Synchrony Technology Blog

Clean. Efficient. Reliable. These attributes are often used to describe magnetic bearings. With no need for lubricants, with no mechanical wear or friction, and with the capability to tailor bearing characteristics to optimize performance, it's no wonder that there's growing excitement about using magnetic bearings in high performance machinery. This is especially true today, where there is much focus on improving the utilization of energy using eco-friendly technologies.

The truth is, the advantages of magnetic bearings have been known for a long time. The principle of using electromagnets, sensors, and active electronics to suspend objects without mechanical contact was demonstrated by Jesse Beams at the University of Virginia back in the 1950s. Despite the long history of magnetic bearings, today only a small fraction of rotating machinery is supplied with magnetic bearings. What's the reluctance towards the widespread use of this technology?

We believe that in the past, the acceptance of magnetic bearings was impeded because the bearings did not meet basic engineering criteria related to performance, simplicity, size, and cost:

Performance. Magnetic bearings must be unconditionally stable for just about any operating condition of the host machine. This includes conditions of high dynamic loading caused by surge, stall, ingestion of liquid slugs, cavitation, motor electrical faults, and other transient conditions.

Simplicity. Magnetic bearings must be easily integrated into new and existing designs of rotating machinery. To facilitate this integration, the bearings should be offered in standard sizes, be easy to mechanically and electrically integrate into the machine, and be accurately modeled using standard techniques. Additionally, the bearings should be simple to optimize and operate, and interface with other plant systems for process control, health monitoring, and trending. The size, quantity, and length of cables between the controller and the magnetic bearings should be kept to a minimum. The overall complexity of the magnetic bearing should be hidden from the machine designer or end user.

Size. The magnetic bearings should be as small as possible to facilitate integration into the rotating machine. The magnetic bearing controllers should be miniaturized so that they can be mounted on or near the machine to reduce the length of cables, reduce EMI, reduce the time to calibrate the bearings, and reduce the footprint of the magnetic bearing system.

Cost. The decision to use magnetic bearings instead of oil-lubricated bearings should be economically justified based on a return on investment (ROI) analysis of acquisition and operating costs. The value of the magnetic bearing system is the elimination of the oil lubrication system, reduction in process downtime, longer machine life, improved machine efficiency, and the reduction in maintenance costs.

At Synchrony, our passion is to massively increase the use of magnetic bearings for existing and new applications. Through a series of design innovations that began when I started Synchrony in 1993, we have systematically improved the performance, simplicity, size, and value of magnetic bearings to the point where our systems are now used in many new applications that were not possible just a couple of years ago. We are seeing rapid acceptance of our products as more customers experience the attributes of magnetic bearings — clean, efficient, and reliable.

I invite you to explore our web site and learn more about us and the products we offer, including magnetic bearings, high speed motors and generators, and power conversion systems. I hope you experience how Synchrony's spirit of engineering excellence, bold innovation, and creativity is being harnessed to improve the next generation of rotating machinery. Your comments are also welcome.