| 摘要 |
PURPOSE:To provide a spindle motor where magnetic fluid never scatters by the magnetic fluid seal devices being provided outside of both bearings between a shaft member and a rotor. CONSTITUTION:This spindle motor is provided with a shaft member 7 fixed to a bracket 5, a rotor 3 supported freely through a pair of ball bearings 10 and 11 by this shaft member 7, a rotor magnet 24 installed on this rotor 3, and a stator 35 arranged opposite to the rotor magnet 24. Furthermore, it is equipped with seal devices 15 and 16, which are provided on both sides of a pair of ball bearings 15 and 16 between the shaft member 7 and the rotor 3, and a passage 8 for air bleeding, which is made in the shaft member 7 and connects the area between both bearings 10 and 11 around this shaft member 17 with the opposite side of the bracket 2 from the rotor 3. |
