A method of noncontact suspension of rotating bodies using electromagnetic forces

Abstract

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.

Unified modelling of passive homopolar and heteropolar electrodynamic bearings

“…Filatov and Maslen presented the theoretical and experimental development of electrodynamic bearings for a highspeed flywheel designed for energy storage applications [9][10][11][12]. A discussion about the influence of the electrical parameters of the rotating conductor has been initiated, and stability issues have been explored more deeply [13].…”

Parameterized Electromechanical Model for Magnetic Bearings with Induced Currents

“…With this model, this can be done on the basis of a few experimental measurements, or on the basis of a finite element model of the bearing. Similar models have already been developed for particular fully passive electrodynamic bearings (4), (5) , but here a macroscopic point of view is chosen as to the electromagnetic phenomena involved in the system, which generalizes the model to any kind of magnetic bearing. Furthermore, there is no need to develop an often complex analytical solution for the magnetic and electric fields.…”

Fundamental considerations on introducing damping to passively magnetically stabilized rotor systems

“…Additionally, passive magnetic bearing systems combine outstanding reliability with relatively low complexity of the bearing element (especially in comparison with active magnetic bearings). Passive stabilization can be achieved using superconducting materials, [1][2][3] electrodynamic effects, [4][5][6][7][8] or permanent magnetic bearings, [9][10][11][12][13] but the common problem is a lack of damping. Electrodynamic and superconducting bearings even introduce instability to the supercritical regime.…”