Axial-Field Electrical Machines???Design and Applications

Axial-field electrical machines (AFM's) offer an alternative to the conventional radial-field machines (RFM's). In the axial-field machine, the airgap flux is axial in direction and the active current-carrying conductors are radially positioned. This paper presents the design characteristics, special features, manufacturing aspects, and potential applications for axial-field electrical machines. The experimental results from several prototypes, including de machines, synchronous machines, and single-phase machines are given. The special features of the axial-field machine, such as its planar and adjustable airgap, flat shape, ease of diversification, etc., enable axial-field machines to have distinct advantages over conventional machines in certain applications, especially in special purpose applications.