JPH05244738

PURPOSE:To obtain a permanent magnet rotor stabilized in the quality thereof by a method wherein the cracking of a magnet or the vibration of a shaft end is prevented upon clamping a plurality of rotor magnets to the shaft of the rotor when the permanent magnet rotor of a synchronous motor such as an AC servomotor and the like employed for the driving source of a robot or an NC device is manufactured. CONSTITUTION:When a plurality of rotor magnets, made by securing cylindrical magnets 13 to the core 12 of a laminated rotor, are pressed into a rotor shaft 11 in accordance with the output of a motor, a minute gap 14 is provided between the axial end faces of the rotor magnets while controlling the positions of the rotor magnets at the side of a press fitting device so that any stress strain is not generated in the rotor core whereby a permanent magnet rotor having stabilized quality in the manufacture thereof can be obtained.