Novel Combination Radial/Axial Homopolar Active Magnetic Bearing

A novel combination radial/axial homopolar permanent-magnet-biased electromagnetic actuator for application in active magnetic bearings is proposed. The design combines the best features of the earlier solutions: shorter axial length, lower part count, lower aerodynamic drag, lower negative stiffness and lower cost typical for combination bearings along with better axial bandwidth typically demonstrated in arrangements of separate radial and axial bearings. Furthermore, for most machines, the actuator topology leads to rotor construction that results in a higher first bending mode frequency than previous designs.