Thermally activated shutdown seals for rotatable shafts
US8356972B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 7, 2009 |
| Grant date | Jan 22, 2013 |
| Priority date | — |
| Expiry date | Sep 5, 2031 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF04D29/146
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A thermally actuated shutdown seal for a rotating shaft having a narrow annular fluid flow path surrounding the shaft. The seal surrounds the shaft with the annulus therebetween during normal operation and constricts against the shaft when the shaft slows or stops rotating. The annulus is maintained open during normal operation by a spacer interposed between opposing ends of a split ring. When the shaft stops rotating, the temperature of the annulus rises, which actuates removal of the spacer from the split ring constricting the split ring against the shaft blocking the annulus. The blocked annulus causes a pressure differential across the seal which urges a polymer seal ring, downstream of the split ring against the shaft which seals the annulus. In one embodiment, the spacer is formed of a meltable material. In a second embodiment, the spacer is removed from the split ring by a thermally responsive actuator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.