The technology behind the electrodynamic bearings are built up on a term called "Magnetic Mirroring" that was launched by Dr Torbjörn Lembke, CTO of Magnetal. Bearings, back in the mid 1990ies.
The upper part, of the picture to the right, shows an un-displaced rotating shaft placed in an electrodynamic bearing system. As can be seen no forces or induced currents exists. This is the ideal operation.
The lower part of the picture, to the right, represents a displaced system. What now happens is that induced, so called, "Eddy Currents" will start to flow. These induced eddy currents will help reposition the shaft by on one side (the side with the compressed air gap) form a repulsive force and on the side (with the larger air gap) there will be an attracting force pulling and re-centering the shaft.
The ingenuity behind the invention is comprehensive design and calculation that controls the Eddy Currents.
It should be noted that on the market today are bearings using active magnetic forces that involves expensive and large electronic control systems. The Magnetal bearing solution is totally controller free and will thus provide a less costly and complex component. The bearing is also physically smaller
Other characteristics is that the stiffness is kept constant and independent of the displacement . this is unlike a traditional ball bearing that has an increasing stiffness related to it. This fact makes the implementation of the bearing in rotordynamic calculations and simulations extremely simple.
In conjunction the bearing is operating in a supercritical mode so passing of certain critical modes can be avoided