| 摘要 |
PURPOSE:To facilitate the assembling, stably feed a magnetic fluid, and facilitate the re-injection by constituting said device with a magnetic fluid reservoir provided inside a shaft and at least one fine hole toward the vicinity of a small gap from the magnetic fluid reservoir. CONSTITUTION:A permanent magnet 1 and a pair of yorks 2 are held by a housing 5, a shaft 4 has a fluid reservoir 8 with an opening at a shaft end, and several fine holes 9 are radially provided from there toward the outer periphery of the shaft. A required quantity of the magnetic fluid is injected and sealed with a scatter prevention plug 10. As the shaft rotates, the fluid is pressed to the side wall of the fluid reservoir by a centrifugal force and is guided to a small gap with the york through the fine hole 9. Thus a fixed quantity of the magnetic fluid is reliably fed to the gap at a seal section. In addition, the fluid can be easily re-injected even when it is decreased by scattering or evaporation and requires to be supplied. |
