| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a brushless motor that can easily detect a zero-cross point precisely and thereby can perform a high-precision drive control even at low speed. <P>SOLUTION: In the brushless motor 1 provided with a motor body 2 comprising a stator 7 including stator winding 7b and a rotor 6 including a rotor core 6a and rotor magnets 6c provided at the outside circumference of the rotor core 6a, predetermined air gaps (magnetic flux medium portions) 6e that has permeability smaller than that of the rotor cores 6a are formed between the rotor core 6a and boundary portions between the N pole and S pole of the rotor magnets 6c, by providing recessed portions 6d formed by cutting out the outside circumferential portions of the rotor cores 6a that face the boundary portions between the N pole and S pole of the rotor magnets 6c. <P>COPYRIGHT: (C)2007,JPO&INPIT |
