Rotor, Manufacturing Method of the Rotor and Motor using the Rotor

摘要

In a rotor having plural permanent magnets secured on a rotary shaft for use in, e.g., an electric motor which is incorporated preferably into a rack-type electric power steering device, a cylindrical cover is fit on the rotary shaft to cover the external surfaces of the plural permanent magnets, and one or both axial end portions of the cylindrical cover are plastically deformed thereby to secure the cylindrical cover onto the rotary shaft. Thus, the cylindrical cover is firmly secured to the rotary shaft and, even when one or more permanent magnets are separated from the rotary shaft or broken, prevents the separated permanent magnets or the broken fragments from scattering within a housing of the motor.