Ferrofluid sealing device
US6305694A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 22, 1999 |
| Grant date | Oct 23, 2001 |
| Priority date | — |
| Expiry date | Nov 22, 2019 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16J15/43
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A ferrofluid sealing device retaining a ferrofluid between a shaft and a pair of inner and outer pole pieces rotating in opposite directions, in which grooves are formed on a shaft surface that faces the inner diameter surfaces of pole pieces. In the sealing device, one of the pole pieces may be made thicker than the other and further a projection portion can be formed on the shaft surface facing the inner peripheral faces of the pole pieces. The sealing device can prevent, even when the ferrofluid seal is operated at a higher rotation speed, splashing of ferrofluid over the surroundings, thereby avoiding staining the surroundings as well as prolonging its lifetime.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.