Pressure insensitive lip seal
US4344631A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 18, 1980 |
| Grant date | Aug 17, 1982 |
| Priority date | — |
| Expiry date | Nov 18, 2000 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB63H2023/327
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A lip seal for preventing the mixing of seawater with an oil cavity around a marine stern tube includes an annular radial flange attached to one end of an axially extending bushing which is encircled by a garter spring. An axially extending foot projects from the bushing into the oil cavity and includes a hydrodynamic profile on its inner surface. A pocket is formed in the sealing face of the bushing and is pressurized with oil by the hydrodynamic profile on the bushing. The pressurized oil pocket balances the water pressure on the outside of the seal, and the hydrodynamic profile forms a fluid film which lubricates the seal and provides the balancing pressure for the pocket. A series of vents can be provided to vent excess oil pressure in the pocket to prevent leakage of oil out of the pocket into the water.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.