Motor

A motor comprising:

• a rotating shaft;
• a rotor comprising a hole in which the rotating shaft is disposed;
• a stator disposed outside the rotor;
• a housing that accommodates the rotor and the stator;
• and
• a commutator comprising a hole in which the rotating shaft is disposed,
• wherein the housing comprises a cover plate,
• wherein the cover plate comprises a brush that comes into contact with the commutator, and
• wherein the commutator comprises a serration portion that is disposed on an outer circumferential surface of the commutator and comes into contact with the brush,
• wherein a height from a bottom end to a top end of the serration portion on the basis of an axial direction of the rotating shaft is higher than a height from a bottom surface to a top surface of the brush,
• wherein a top end of the serration portion is disposed to be higher than a top end of the brush on the basis of an axial direction of the rotating shaft, and a bottom end of the serration portion is disposed to be lower than the top end of the brush, and
• wherein a boundary between a front surface of the brush, which comes into contact with the serration portion, and a top surface of the brush is an inclined surface, and a boundary between the front surface of the brush, which comes into contact with the serration portion, and a bottom surface of the brush is an inclined surface.