Magnetic bearings for large clearances

Calnetix Technologies, which develops and manufactures high-speed permanent magnet motor generators, power electronics and magnetic bearings for a variety of applications and industries, recently received a patent on the company's radial magnetic bearing invention. It is the fifth patent spearheaded by Principal Research Engineer Alexei Filatov.

The large clearances that are now practical with this new invention make Calnetix's patented magnetic bearings an ideal choice for systems where sizeable particles are present in the processing gases or fluids, which could cause damage to a machine utilizing traditional magnetic bearings with smaller gaps.

As another example, large clearances may be needed when pumping delicate liquids, such as blood, where small clearances would result in large shear forces that could destroy the cells.

Filatov said, "Our invention pertains to applications requiring large radial clearances between stationary and rotating parts, such as pumps, fans and compressors, and more specifically for hermetically sealed systems. For example, the requirement may arise when the rotating part is submerged into some sort of a chemically aggressive liquid or a gas that has to be isolated from the stationary part of a machine by means of a hermetically sealed can."