Abstract: A spindle motor comprises a stationary shaft, a rotor hub rotatably mounted by ball bearings to the stationary shaft, and annular sealing members disposed between the outer surface of the stationary shaft and the inner side of the rotor hub axially outwardly of the ball bearings. The sealing member is directly fitted onto the outer race of the corresponding ball bearing. The outer race of each ball bearing is high precision finished so that the sealing member is definitely coaxial with the stationary shaft regardless of the finishing accuracy on the inner side of the rotor hub. Accordingly, the radial distance between the inner side of the sealing member and the outer surface of the stationary shaft can be minimized with high precision offering an excellent labyrinth effect.

Abstract: A slotless, brushless DC motor having thin, flat coils fixed to the inner surface of a thin insulating cover attached to the cylindrical inner surface of the stator core of the motor. The coil ends are bent and fixed to the insulating cover over the end faces of the stator core. The structure provides a reduced air gap increasing the rotor efficiency and a reduced axial length of the motor. The coils are arranged such that adjacent coils sides are in contact with each other and may be connected in a Y-configuration or a .DELTA.-configuration.