| 摘要 |
PURPOSE:To adopt a dynamic-pressure fluid bearing mechanism wherein a spindle motor is provided with excellent characteristics such as a simple structure, low costs, a small size, a low power consumption, a low noise and the like by obtaining an air discharge structure problems such as the avoidance of the blockade of the air, the discharge of air bubbles and the prevention of the contamination of an apparatus in the assembly of the dynamic-pressure fluid bearing mechanism is solved. CONSTITUTION:A communication groove 23b is formed at the outer circumferential side of a sleeve metal 21 constituting a dynamic-pressure fluid bearing mechanism, i.e., at the inner circumference of a housing 23a. Thereby, when a lubricative fluid in a proper amount is injected into the inside of a lower assembly 20 and the free end of a shaft 12 at an upper assembly 15 is inserted, the air at the inside is not confined and can be discharged, and an assembly operation can be performed smoothly. When the shaft 12 is inserted, there may be a fear that the lubricative fluid together with the air is discharged form the communication groove 23b. As a result, a space in which the fluid is stored is formed on the side of an opening edge 21 a so that the lubricative fluid is not scattered and lost. |
