Abstract: A multiple disk, pancake, self-fed brushless dc motor characterized by high power density has a variable number of interleaved, axially spaced rotor and stator disks. The annular rotor disks are made of high coercive force permanent magnets such as cobalt-samarium and ferrites which do not demagnetize easily. The annular stator disks are yokeless and include a spirally wound laminated magnetic core made of steel strip or amorphous metal ribbon with opposing sets of stator slots and windings on both sides of the core. The permanent magnet machine can be operated as a generator.