Abstract: A bearing structure includes a bearing having a shaft hole formed by an inner wall of the bearing. The outer periphery of the bearing has multiple outer walls and multiple deformable zones. The multiple outer walls are located at the axial direction of the same radius circumference with the center of the shaft hole as a center of circle thereof. Each of the multiple deformable zones is provided on the outer periphery of the bearing between any two outer walls, and is deformable to absorb an outer stress. When the bearing is closely mounted in a shaft tube during a punching process, the multiple deformable zones of the outer face of the bearing may absorb the outer stress, thereby preventing the inner wall of the bearing from being deformed.

Abstract: An oil-impregnated bearing and rotor shaft combination includes an oil-impregnated bearing with a central hole for pivotally holding a rotor shaft. The oil-impregnated bearing is mounted in a hole of an axle tube in a slip-fit manner. Each of two ends of the hole of the axle tube is sealed by a cap by means of tight engagement to thereby restrain the oil-impregnated bearing in the hole of the axle tube and between the caps. The rotor shaft is extended through an opening in the upper one of the caps and through the central hole of the oil-impregnated bearing with a lower end of the rotor shaft pivotally supported by an inner side of the lower one of the caps.

Abstract: A brushless DC motor fan includes a rotor, a stator, a drive circuit, and a conversion circuit. An input of the conversion circuit is connected to an AC power source. The conversion circuit drops the voltage of the AC power source before connecting to a sensor element and a drive circuit. The drive circuit outputs alternately conducted current with positive/negative polarity to make the coil of the stator be alternately conducted, thereby generating an alternating magnetic field for driving the rotor.

Abstract: A spindle motor for a disc drive, such as a CD-ROM drive, is provided. This spindle motor is a brushless motor of a single-phase axial-winding and radial-gap type including a stator, a rotor coupled to said stator, and a driving circuit for supplying a driving signal to the stator to rotate the rotor. The stator includes a pair of upper and bottom salient-pole pieces formed with a plurality of tooth-like portions serving as salient-poles. The peak surface of each tooth-like portion is formed into a symmetrical convex shape, which minimizes the cogging torque of the motor. Further, the use of a phase-adjuster in the driving circuit allows the motor to produce large output torque at high speeds. The output characteristics of this spindle motor meet the requirements of high speed CD-ROM drives.