Motor

A motor comprising:

• a housing;
• a stator disposed inside the housing;
• a rotor disposed inside the stator;
• and
• a shaft coupled to the rotor,
• wherein the rotor includes a rotor core and a plurality of magnets disposed on an outer circumferential surface of the rotor core,
• wherein the rotor core includes grooves concavely disposed at a boundary between an inner circumferential surface and an upper surface of the rotor core,
• wherein the shaft includes a first body, a plurality of blades extending from an upper surface of the first body in a radial direction, and a plurality of protrusions protruding downward from a lower surface of the first body,
• wherein protrusions of the plurality of protrusions of the shaft are disposed, respectively, in grooves of the plurality of grooves of the rotor core, and
• wherein a Hall sensor is disposed above the plurality of blades, the Hall sensor facing upper axial ends of the magnets of the plurality of magnets of the rotor.