A rotor device for an electric motor and/or generator with a rotor body and a plurality of magnets, wherein the rotor body comprises a rotor shaft seat and a plurality of magnet receptacles arranged coaxially with the rotor shaft seat. The magnets are rigidly positioned and mounted in the magnet receptacles by means of a plastic molding compound injected into the magnet receptacles, which plastic molding compound forms at least one cover element that covers the openings of the magnet receptacles at least partially. The cover element comprises at least one magnet wheel centering means and/or at least one magnet wheel alignment means. The invention furthermore relates to a rotor and a motor with such a rotor device as well as to a production method.