CERAMIC RING SUPPORT FOR GAS TURBINE BLADE OUTER AIR SEAL
Publication Date: 2005-Oct-12
The IP.com Prior Art Database
Guy Bouchard, Pratt & Whitney Canada: INVENTOR [+2]
CERAmic ring support for turbine blade outer air seal
Inventors: Guy Bouchard, Gilles Carrier
The present invention relates generally to gas turbine engines, and particularly to a support for a ceramic turbine ring air seal.
BACKGROUND OF THE INVENTION
The use of ceramics components is well known in gas turbine engines. Ceramics have well known advantages over metallic components, such as a high resistance to temperature permitting operation at high temperatures without requiring cooling, and a low thermal coefficient of expansion compared to metals. Ceramics do have negative properties, being relatively brittle and not very tolerant to high loads. Nonetheless, using ceramic components in the hot section of gas turbine engines is attractive because of their ability to endure high temperatures without requiring cooling. Mounting ceramic components with, or adjacent to, metallic components is however problematic.
As ceramic components have very different thermal responses than metallic components, mounting them together is difficult as the two materials will expand and contract at different rates when exposed to high temperature variations. As such, while providing a turbine shroud ring made of ceramic is advantageous, it is often difficult to support within the metallic turbine case such that expansion of both parts is independently possible, while a precise blade tip clearance is nevertheless maintained between the turbine blades and the sealing ceramic shroud ring.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved turbine shroud ring assembly for use in a gas turbine engine.
It is another object of the present invention to provide a support arrangement for a ceramic turbine shroud ring.
It is another object of the present invention to provide a ceramic turbine shroud ring support capable of tolerating thermal growth mismatches between the ceramic shroud ring and the metallic turbine casing.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages of the present invention will become apparent from the following detailed description, taken in combination with the appended drawings, in which:
Fig. 1 is a gas turbine engine having a ceramic turbine sealing ring mounting assembly according to the present invention.
Fig. 2 is an enlarged, partial cross-sectional view of a turbine portion of the gas turbine engine of Fig. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to Fig. 1, a gas turbine engine 10, generally has a compressor section 12, a combustion section 14, and a turbine section 16. The turbine section comprises at least one turbine stage, each stage having at least a vane ring 18 and a turbine rotor 20. Hot combustion gases from the combustion chamber are directed through the turbines such that energy can be extracted therefrom. To avoid tip gas leakage, the rotating turbines are shrouded by a sealing ring radially disposed a...