Turbine passive thermal valve for improved tip clearance control
US6116852A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 11, 1997 |
| Grant date | Sep 12, 2000 |
| Priority date | — |
| Expiry date | Dec 11, 2017 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF01D11/24
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A gas turbine engine blade tip clearance control system and method is described. An annular housing is formed about an engine casing to which an annular shroud segment assembly is secured and closely spaced about blade tips of a stage of blades. The annular housing forms an air passage means communicating with the casing for directing a cooling air stream to the casing. A thermally operable passive ring valve is formed by two overlapped metal ring segments having a dissimilar coefficient of thermal expansion selected whereby to produce a radial gap between the ring segments when the valve temperature reaches a predetermined value. The radial gap admits a cooling air flow into the housing for cooling the casing and its associated shroud segment assembly to control radial growth and thereby prevent blade tip pinching.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.