Manufacturing costs of releasable permanent magnet rotors or asynchronous squirrel cages should be reduced. Accordingly, a rotor is proposed which includes at least one ring-shaped fastening device (23) secured in fixed rotative engagement to one of the end faces of a magnet device (21, 22) and for form-fitting or force-locking connection to a shaft (25). This makes it possible to eliminate the need for a special bearing sleeve, and the laminated armature core (21) can be provided with a larger axial hole diameter. As a result, the minimum joint pressure can be reduced so that deformations of the spindle and complicated refinishing processes can be avoided. In addition, less stringent manufacturing tolerances of the spindle (25) can be selected.