Shaft seal device
US5421593A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 5, 1993 |
| Grant date | Jun 6, 1995 |
| Priority date | — |
| Expiry date | Aug 5, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S277/927
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A shaft seal device comprises two mechanical seals for sealingly separating a sealed fluid region from an atmospheric region. A shaft is rotatable about an axis and extends through a casing from a sealed fluid region to an atmospheric region. The mechanical seals separate the sealed fluid region and the atmospheric region by a purge region formed between the mechanical seals. Each mechanical seal comprises a first seal ring fixed on the shaft and a second seal ring slidable in the axial direction and pressed against the first seal ring. The mechanical seal separating the sealed fluid region from the purge region is a contact type seal so that the fluid pressure of the sealed fluid region acts as a back pressure on the second seal ring. The mechanical seal separating the atmospheric region from the purge region is non-contact type seal so that the fluid pressure of the purge region acts as a back pressure on the second seal ring. The purge fluid region is charged with a gas such as nitrogen at a pressure lower than the pressure in the sealed fluid region.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.