| 摘要 |
<P>PROBLEM TO BE SOLVED: To minimize gas load or pressure load applied to each annular ferrofluidic seal. <P>SOLUTION: This multi-stage ferrofluidic seal 30B includes a plurality of annular ridges defined and spaced apart on one or both of an outer surface 46B of a shaft and an inner surface 49A, 49B of a pole piece so that the shaft 31B is situated in close proximity with the pole piece 47A, 47B by means of the annular ridges 71, a plurality of annular ferrofluidic seals 73 respectively formed on tops of the annular ridges so as to substantially seal close-proximity gaps between the shaft and the pole piece, and at least one annulus 65 respectively situated in at least one of the spaces 72 between the annular ridges so as to encircle the shaft, and each annulus serves to occupy space within the multi-stage ferrofluidic seal so as to reduce the gas load therein. <P>COPYRIGHT: (C)2007,JPO&INPIT |
