SPINDLE MOTOR FOR DIGITAL VIDEO DISK

摘要

PURPOSE: A spindle motor for a DVD(Digital Video Disk) is provided to improve precision in rotation of a shaft and to inhibit an unbalance state of a rotor by holding the rotor with a magnetic force of a magnet between a sleeve and a hub. CONSTITUTION: A hollow sleeve(11) is formed on a housing(10), and a core(14) having a winding coil(15) is joined to outside of the housing. The core adopts a core insulator(16) for insulation with the housing and has a shaft(12) rotatable in the sleeve. A space between the shaft and the sleeve is filled with oil for generating dynamic pressure. A hub(17) is assembled to the upper end of the shaft to rotate a rotor(18). A lift inhibition unit(24) is mounted between the hub and the sleeve. A movable magnet(25) is formed on the upper portion of the sleeve while a fixed magnet(26) is formed on the lower portion of the hub. Two magnets face to each other with different polarities to generate an attractive force. The magnetic force has strength for preventing the rotor from moving up when a door is opened. Therefore, the rotor is not lifted up.