发明名称 |
Ferrofluid composition, method of making, and apparatus and method using same. |
摘要 |
<p>A stable ferrofluid composition and a method of preparing and using the ferrofluid composition, and a ferrofluid seal apparatus is described. The ferrofluid composition comprises a liquid carrier, ferromagnetic particles sufficient to provide magnetic properties to the ferrofluid dispersed in the liquid carrier and a dispersing amount of a cationic surfactant to provide a stable ferrofluid composition. The stable ferrofluid compositions have improved electrical conductivity and are useful, e.g. in sealing computer disc drives. Thus, an electrically conductive ferrofluid-film-bearing apparatus and seal apparatus (40) for a shaft (46) employs a low-viscosity, electrically conductive ferrofluid composition (62, 50) as an O-ring seal and as a ferrofluid bearing surrounding shaft (46) which composition comprises a liquid carrier, and contains in combination an electrically conductive amount of a cationic surfactant and dispersed carbon particles, to obtain a low-electrical-resistivity ferrofluid having a low viscosity.</p> |
申请公布号 |
EP0206516(A2) |
申请公布日期 |
1986.12.30 |
申请号 |
EP19860303840 |
申请日期 |
1986.05.21 |
申请人 |
FERROFLUIDICS CORPORATION |
发明人 |
BORDUZ, LUCIAN;KULDIP, RAJ;GOWDA, HANUMAIAH L. |
分类号 |
G11B19/20;G11B33/14;H01F1/44 |
主分类号 |
G11B19/20 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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