| 摘要 |
A spindle motor comprises a double row bearing device (4) including a shaft (5), a sleeve (9) surrounding the shaft (5), and a pair of upper and lower rows of balls (12a,12b). A cylindrical bearing holder (2) extends upwardly from a base (1) of the spindle motor for accommodating the sleeve (9) within a vertical bore (3) of the holder (2), and a rotor hub (6) is mounted on the shaft (5) for journaling the rotor hub (6) rotably on the base (1). A reduced inner diameter portion (3a) of an inner diameter smaller than the outer diameter of the sleeve (9) is formed on the inner surface of the bore (3) of the bearing holder (2) between the upper and lower larger inner diameter portions to urge the sleeve (9) inwardly by the reduced inner diameter portion (3a) to deform it elastically to form a squeezed portion (9a) protruding inwardly of the sleeve (9) between the upper and lower rows of balls (12a,12b). <IMAGE> |
