Motor apparatus

1. A motor apparatus comprising:

a stator having a plurality of teeth formed in a circumference thereof;

a rotor rotatably installed in the stator, and having a plurality of magnets disposed in a circumference thereof; and

a 3-phase coil part having a plurality of coils wound around the teeth, respectively,

wherein the coils having a preset phase difference are arranged in parallel,

wherein:

the 3-phase coil part comprises a U-phase coil, a V-phase coil, and a W-phase coil;

the U-phase coil includes first groups of the coils having a first phase difference arranged in parallel, each of the first groups including the coils having the same phase difference arranged in series;

the V-phase coil includes second groups of the coils having a second phase difference arranged in parallel, each of the second groups including the coils having the same phase difference arranged in series;

the W-phase coil includes third groups of the coils having a third phase difference arranged in parallel, each of the third groups including the coils having the same phase difference arranged in series;

the first phase difference is 20° to 30°, and the coils in each of the first groups mechanically have an angle difference of 180° therebetween and are electrically in-phase;

the second phase difference is 20° to 30°, and the coils in each of the second groups mechanically have an angle difference of 180° therebetween and are electrically in-phase;

the third phase difference is 20° to 30°, and the coils in each of the third groups mechanically have an angle difference of 180° therebetween and are electrically in-phase;

the rotor comprises 14-pole magnets;

the stator comprises 18 coils;

the first groups include, counting consecutively in a counter-clockwise direction on the stator, a first coil and a tenth coil wound in series, a fifth coil and a fourteenth coil wound in series, and a sixth coil and a fifteenth coil wound in series, such that the first-tenth coil set, the fifth-fourteenth coil set, and the sixth-fifteenth coil set are arranged in parallel;

the second groups include, counting consecutively in a counter-clockwise direction on the stator, a second coil and an eleventh coil wound in series, a third coil and a twelfth coil wound in series, and a seventh coil and a sixteenth coil wound in series, such that the second-eleventh coil set, the third-twelfth coil set, and the seventh-sixteenth coil set are arranged in parallel; and

the third groups include, counting consecutively in a counter-clockwise direction on the stator, a fourth coil and a thirteenth coil wound in series, an eighth coil and a seventeenth coil wound in series, and a ninth coil and an eighteenth coil wound in series, such that the fourth-thirteenth coil set, the eighth-seventeenth coil set, and the ninth-eighteenth coil set are arranged in parallel.