A method of noncontact suspension of rotating bodies using electromagnetic forces

We propose and demonstrate a method of noncontact dynamically stabilized suspension which utilizes a combination of static interaction between permanent magnets and dynamic interaction between room-temperature conductors and magnets. The suspension features a combination of properties that are not collectively provided by any of the prior technologies, including load capacity and stiffness sufficient for many applications, low rotational loss, high efficiency, high reliability, and robustness to the system parameter variations and external disturbances. The rotational loss is expected to be virtually zero if only axial loading is applied: a condition which is very easy to satisfy in stationary applications if the rotation axis is vertical. The suspension is stable for any speed above a certain critical value. The validity of this method has been demonstrated by building and testing a prototype in which noncontact suspension of a 3.2 kg rotor is achieved when it rotates at spin speeds above 18 Hz. (C) 2002 American Institute of Physics.