SPINDLE MOTOR AND DISK DRIVING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a shaft-fixed spindle motor for preventing the leakage or shortage of lubricating oil due to a pressure difference between upper and lower capillary seal parts.SOLUTION: The spindle motor includes a stationary part 2, and a rotary part 3. The stationary part 3 includes a shaft 41 having a thrust plate 42. The rotary part 3 includes a sleeve portion 43 into which the shaft 41 is inserted and which has one axial end face opposed to the thrust plate 42, and a first seal member 44 opposed at its opposite side to the sleeve portion 43 to the thrust plate 42. The thrust plate 42 has a plate communication hole 51 communicating a first thrust clearance between the sleeve portion 43 and itself with a second thrust clearance between the first seal member 44 and itself. The sleeve portion 43 has a sleeve communication hole 52 communicating the other axial side with the first thrust clearance 54. A communication passage from the first capillary seal part through the plate communication hole 51 and the sleeve communication hole 52 to the second capillary seal part is filled up with lubricating oil 46.