Motor apparatus

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;
• 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 coils having a first phase difference arranged in parallel, the first groups including the coils that mechanically have an angle difference of 180° therebetween, are electrically in-phase, and are arranged in parallel;
• the V-phase coil includes second groups of coils having a second phase difference arranged in parallel, the second groups including the coils that mechanically have an angle difference of 180° therebetween, are electrically in-phase, and are arranged in parallel;
• the W-phase coil includes third groups of coils having a third phase difference arranged in parallel, the third groups including the coils that mechanically have an angle difference of 180° therebetween, are electrically in-phase, and are arranged in parallel;
• the first phase difference is 20° to 30°, and the coils in the first groups have a phase difference of 180° and are arranged in parallel;
• the second phase difference is 20° to 30°, and the coils in the second groups have a phase difference of 180° and are arranged in parallel;
• the third phase difference is 20° to 30°, and the coils in the third groups have a phase difference of 180° and are arranged in parallel;
• the rotor comprises 14-pole magnets;
• and
• the stator comprises 18 coils.