| 摘要 |
<p>A single-stage, ferrofluid, rotary-shaft seal apparatus of extended seal life is particularly adapted for use as an exclusion seal with a computer-disc-drive spindle. The seal apparatus comprises: an annular permanent magnet; first and second pole pieces of identical width, having an L-shaped, crosssectional configuration at the one end thereof, with the one end thereof extending into a close, noncontacting relationship with the surface of the shaft to form a defined radial gap, while the inside diameter of the projection at each end forms an interstage region; and a ferrofluid retained by magnetic flux in the radial gap and interstage region, to form a single-stage, ferrofluid, O-ring seal on the surface of the shaft.</p> |
