| 摘要 |
PROBLEM TO BE SOLVED: To provide a magnetic disk, of which the number of components and the assembling man-hour is few so that a manufacturing cost can be reduced, and in which the accuracy of suppressing a shaft deflection of a motor can be improved, so that the magnetic disk has a high recording density and is highly reliable. SOLUTION: A spindle 5 comprising a two-stage shaft having a large diameter part and a small diameter part is housed in a sleeve 10 of a ball bearing body. The small diameter part of the spindle 5 is provided with an inner race 8 having a rolling groove 7 on the outer periphery and the sleeve 10 has a rolling groove 12 on the inner diameter, wherein a plurality of balls 14 are provided between both grooves. The large diameter part of the spindle 5 has a rolling groove 6 on the outer periphery and the sleeve 10 also has a rolling groove 11 on the inner diameter, wherein a plurality of balls 13 are provided between both grooves. The sleeve 10 and the spindle 5 constituting the ball bearing body are formed integrally with the components of the motor, including a rotor 9 and yoke holder 2, both are made of the same material for making the sleeve and spindle. The magnetic disk has the motor constituted as described above.
|
