Patent ID: 7023115

Claim:
A motor comprising: a rotor including a shaft and a magnet surrounding a portion of the shaft; a stator surrounding the magnet of the rotor with a gap therebetween, and adapted to generate a magnetic field thereby causing the rotor to rotate around an axis of the shaft; a rotor sleeve having a cylindrical portion and a flange provided at one end of the cylindrical portion, the rotor sleeve being provided between the magnet and the shaft so as to fixedly hold the magnet and the shaft together; a boss having a circular shape with a center hole for allowing the shaft to rotatably pass therethrough, and being formed with the stator so as to oppose the flange of the rotor sleeve; a plurality of bearing balls rotatably disposed between the boss and flange of the rotor sleeve, wherein an inner surface of the boss is beveled to form a conical configuration with a diameter increasing from the center hole of the boss; and wherein the rotor sleeve has a plurality of partitioning protrusions formed on the flange, the partitioning protrusions being adapted to prevent the bearing balls from coming in contact with one another and to allow the bearing balls to freely rotate.