A low loss motorized spindle suspended by magnetic bearings with two radial homopolar active magnetic bearings (AMB) and one axial permanent magnetic bearing (PMB) was established

and the main design procedure and configuration parameters of the system were presented.The dynamic characteristics of the system were analyzed by theoretical calculations and verified by high-speed rotation tests.The results show that the system has simpler structure

less power consumption

and is able to get across the first two critical speeds and operate at 40000r/min safely

with maximum amplitude of the rotor up to 7μm.