Patent ID: 7589442

Claim:
A motor comprising: a stator; a rotor rotatably disposed around the stator; and a rotor cup having cooling-holes formed at the bottom part thereof for allowing external air to flow into the inside of the rotor cup therethrough, and lower blades formed at the bottom part thereof for generating a blowing force, the rotor being fixed to the rotor cup at the inner circumference thereof, wherein each of the lower blades protrudes from one side of each of the cooling-holes towards the stator, wherein each of the lower blades and the cooling-holes has an acute sloping angle to the line extended in the rotating direction of the rotor cup and perpendicular to the radial direction of the rotor cup, and wherein a plurality of upper blades are located above the top of the rotor for discharging external air, which flows into the rotor cup through the cooling-holes formed at the bottom part of the rotor and then passes through the stator, to outside of the rotor cup, and wherein a plurality of vents are located at a lower circumferential surface of the rotor cup, a bottom of the vents is located above a bottom of the rotor cup, and a top of the vents is located above a top of the lower blades such that the air introduced into the inside of the rotor cup through the cooling holes formed at the bottom of the rotor cup collides with the stator and is discharged to outside of the rotor cup without passing through the stator.