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.
Previously, the authors have described a method of dynamically stabilized noncontact electromagnetic suspension of rotating bodies. The method makes use of the dynamic interaction between stationary and rotating sets of conductors and permanent magnets. The validity of this method has been demonstrated by building and testing a prototype in which noncontact suspension of a 3.2 kg rotor was achieved when it rotates at speeds above 18 Hz. A stability condition for that method of suspension was obtained with certain simplifying assumptions. One of these assumptions was that the inductive component of the stationary conductors is negligible. Here, we present modified stability conditions which take the inductance of the stationary conductors into consideration. One of the predicted effects is that nonzero inductance may cause significant reduction of the minimum stable levitation speed. Consequently, careful choice of the electrical properties of the stationary coils may significantly enhance the performance of the suspension.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.