| 摘要 |
PURPOSE:To provide a brushless motor having reduced NRR and enhanced impact resistance and suitably employed in high density hard disc. CONSTITUTION:When current is fed to a coreless coil 60 while controlling the conducting direction, magnetic fields generated from the coreless coil 60 and a magnet 56 interact to move a hub 54 in the direction shown by an arrow F1 (or oppositely thereto). In this regard, lubricant is collected through V- grooves 70, 72 made in the shaft 50 to float the rotor section in the tangential direction and thrust direction of the shaft 50 thus realizing noncontact rotation thereof. Since a hard disc 36 rotates stably through the function of such dynamic bearing, NRR is reduced. Furthermore, impact due to external vibration is reduced through function of attracting magnets 64, 66 and removal of the rotor is prevented by means of a stopper 8. |
