Micro PM Motors Levitated by two Types of Active Magnetic Bearings

This paper describes magnetically levitated micro PM (permanent magnet) motors by two different types of active magnetic bearings (AMBs). The micro PM motors consist of a cylindrical rotor (2.0×10), a pair of electromagnets, a pair of photo diodes, and an analog PD controller. The motors are characterized by the small rotor levitated without mechanical contacts and one-axis controlled AMB with the analog PD controller. Horseshoe-shaped electromagnets and cylindrical ones are applied to the AMB. The rotor successfully rotates levitating in the center of the electromagnets. In this paper, dynamic characteristics of the two types of micro PM motors are discussed.