Patent ID: 6285104
Filing Date: 2001-09-04
Classification: H02K

Abstract:
A torque ripple-reduced alternating-current motor, comprising:a plurality of slots for arranging a winding on a stator, the slots being located on the circumference of the stator, wherein a winding of each phase is looped through each of the slots so that the product of the number of turns in one of the slots on the stator and the current is the phase and amplitude of a current phasor represented by amperes and the number of turns and becomes almost equal to the product in each of the other slots when a polyphase sinusoidal alternating current having a number of phases equal to a number of phases of the motor is applied;a plurality of teeth on the stator, wherein a position in a direction of rotor rotation of each of the teeth is uniformly located on an inner radius of the stator and the slots are formed to have an area relationship such that a cross-sectional area of each of the slots is roughly proportional to the amount of windings in each of the slots; anda rotor comprising a plurality of magnetic poles, including north poles and south poles, placed such that a position in a direction of rotor rotation of each of the magnetic poles is shifted to the direction of rotor rotation by NN/NR of a 1-slot pitch against a position located on an equivalent spacing, wherein NR is an integer equal to the numbers of magnetic poles on the rotor and NN is an integer between 1 and NR-1.