Abstract: A silicon-steel structure for motor comprises a silicon-steel plate made of magnetic material. The silicon-steel plate comprises a main body of rectangular shape when being expanded and a plurality of tooth portions on top and bottom sides of the main body. The tooth portions are integrally formed on top and bottom sides of the main body and have same pitch. Moreover, the tooth portions on top of the main body are complementary and staggered with the tooth portions on bottom of the main body. The tooth portions are bent vertically with respect to the main body and the main body is rolled to form a cylindrical shape to form a silicon-steel structure for motor.

Abstract: A motor having a magnetic oil seal structure comprises a bearing sleeve, an oil-retaining bearing, a coil set, a rotor, a fastening ring, a magnet and magnetic fluid. The bearing sleeve has a receiving space. The oil-retaining bearing is received in the receiving space. The coil set is slipped outside the bearing sleeve. The rotor has an axis rotatably inserted into an axial hole of the oil-retaining bearing. The fastening ring is fastened on the axis and located above the oil-retaining bearing. The magnet is above the fastening ring. The magnetic fluid is provided between the magnet and the axis of the rotor. Magnetic force between the magnetic fluid and the magnet lets the magnetic fluid be tightly absorbed in the gap between the axis and the magnet to form a magnetic oil seal circuit, hence preventing the oil-retaining bearing from losing oil and greatly increasing its lifetime of use.

Abstract: An electrical fan comprising a blade module and a coil module. The blade module includes a space defined therein, and a shaft. The space has a bottom where an end portion of the shaft is embedded. The coil module includes an oil-retaining bearing, an oil-retaining ring, and a shaft sleeve. The shaft sleeve has an internal flange at a top thereof. The oil-retaining bearing is mounted inside the shaft sleeve, and the oil-retaining ring is clamped between the internal flange and the oil-retaining bearing once the shaft of the blade module has penetrated through the shaft sleeve and the oil-retaining ring of the coil module. Via the oil-retaining ring, the lubricant oil is retained in the oil-retaining bearing, thereby preventing loss and evaporation of lubricant oil.