Piston ring assemblies for high temperature seals
US5037115A · kind A · utility
Inventor
Key dates
| Filing date | Sep 11, 1989 |
| Grant date | Aug 6, 1991 |
| Priority date | — |
| Expiry date | Sep 11, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S277/931
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
In a turbine inclusive of: a turbine shaft having a longitudinal axis, a steam pipe, a shell circumadjacent the pipe, the pipe and shell being shiftable in vertical and transverse and axial directions relative to the longitudinal axis of the shaft, and a seal assembly disposed between the pipe and shell and comprising a stack of interdigitated relatively large and small piston rings, the improvement comprising: each large ring loosely fitting inside the shell during nonoperative conditions and firmly and sealingly engaging the shell during operative conditions; and having a coefficient of thermal expansion greater than that of the shell for expanding at a rate faster than the expansion rate of the shell under a condition of increased temperature, each small ring loosely fitting around the pipe during nonoperative conditions and firmly and sealingly engaging the pipe during operative conditions; and having a coefficient of thermal expansion less than that of the pipe for expanding at a rate slower than the expansion rate of the pipe under a condition of increased temperature, with the large and small rings tightening upon the respective shell and pipe respectively under an increasin…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.