COUPLING STRUCTURE OF PERMANENT MAGNET OF ROTOR IN BRUSHLESS DC MOTOR

摘要

PURPOSE: A coupling structure of a permanent magnet of a rotor in a brushless DC motor is provided to reduce a cogging torque and a ripple of counter electro-motive force without deformation of the permanent magnet by forming differently intervals between an N pole and an S pole and the intervals of the next N pole or the next S pole. CONSTITUTION: The first N-pole permanent magnet(21) of plural N-pole permanent magnets(20) is adhered to a yoke(10). The first S-pole permanent magnet(31) of plural S-pole permanent magnets(30) is adhered in the first interval(α) from a position of the first N-pole permanent magnet(21) of the yoke(10). The second to the n-th N-pole permanent magnets(22 to 25) are adhered in the second interval(β) from the position of the first S-pole permanent magnet(31). The second S-pole permanent magnets(32 to 35) are adhered in the first interval(α) from the positions of the second to the n-th N-pole permanent magnets(22 to 25), respectively. The first interval(α) is narrower than the second interval(β).