US Patent 7579744 Rotor structure of an axial gap rotating electrical device

An axial gap rotating electrical device includes a stator and a rotor. The stator has a stator core and a stator coil. The rotor is disposed in an axial direction with respect to the stator. The rotor includes a plurality of separate rotor components circumferentially arranged. Each of the rotor components includes a permanent magnet facing the stator core and a high-strength member enveloping an outer surface of the permanent magnet. The high-strength member is configured to prevent a centrifugal force on the permanent magnet from being transmitted between adjacent ones of the high-strength member during a rotation of the rotor.