Patent ID: 6911756

Claim:
A rotor for a motor, comprising a body formed by multiple silicon steel sheets securely abutting one another, each silicon steel sheet having a through hole centrally defined therein to define a passage in the body for receiving a shaft of the motor and multiple apertures defined in an outer periphery thereof at equal intervals to define multiple grooves in an outer periphery of the body, a magnet element longitudinally securely received in a corresponding one of the multiple grooves in the body, each aperture having a bottom and an opening defined in the outer periphery of each of the silicon steel sheets opposite to the bottom of the aperture, the opening having a width narrower than that of the bottom and centrally corresponding to the bottom, a raised portion having an arcuate contour and extending from the bottom of each of the apertures in each of the silicon steel sheets toward the opening, the raised portion abutting a bottom of the magnetic element when the magnetic element is received in the groove in the body for forming a magnetic field with a sine wave due to the rotating rotor, wherein two concave portions are respectively defined in two opposite ends of the bottom of each of the apertures and extend radially and circumferentially to the raised portion centrally located between the two opposite ends.