Laboratory Tests on an Interconnected Four Poles Magnetic Bearing

A new structure for active magnetic bearings, based on a successfull idea used in self-bearing motors, has been recently discussed in the literature. A flux interconnection characterizes this idea, and theoretical results predict some advantages of this new model, when compared with the traditional one, with independent flux paths. As an example, a greater equivalent stiffness is expected for this new type of bearing. Two recently built prototypes were used to check whether these expectations really hold true. The main goal of this paper is to present and discuss the prototype details.