Industrial gas turbine multi-axial thermal isolator

Abstract

A multi-axial thermal isolator device for isolating structures formed of differing materials. The device is rigidly attached to both structures and is capable of movement as the result of relative thermal expansion of the structures. The device has a substantially C or Z-shaped configuration with a curved portion forming an angle θ in the range of about 0-10 degrees. The device provides a means for thermal decay between adjacent structures when the parts are subjected to large changes in temperature.

We claim:  
     
         1 . A thermal isolator device for joining two structures having differing rates of thermal expansion, comprising: 
 an isolator structure having a middle portion and pair of opposite disposed end portions forming a curved configuration;    each end portion having a fastening assembly adaptable for rigidly joining one of the two structures; and    the middle portion capable of relative to the end portions while thermally isolating the attached structures from one another.    
     
     
         2 . The thermal isolator device according to  claim 1 , wherein each fastening assembly comprises a flange portion mounted on one end of the structure with a plurality of through openings extending through each flange portion to allow connecting members to extend through and rigidly connect each flange portion with one of the structures.  
     
     
         3 . The thermal isolator device according to  claim 1 , wherein the middle and end portions of the structure form a substantially C-shaped configuration  
     
     
         4 . The thermal isolator device according to  claim 1 , wherein the middle and end portions of the structure form a substantially Z-shaped configuration.  
     
     
         5 . The thermal isolator device according to  claim 1 , wherein the middle portion of the structure includes a pair leg portions forming an angle θ in the range of about 0-10 degrees.  
     
     
         6 . The thermal isolator device according to  claim 5 , wherein the pair of leg portions form an θ of substantially 5 degrees.  
     
     
         7 . The thermal isolator device according to  claim 1 , wherein the structure has a generally cylindrical configuration with a length L and radius from a center line R selected so that the ratio of the length to the radius, L/R is in the range of about 0.2 to 0.6.  
     
     
         8 . A thermal isolator device for joining a thick, heavy combustor casing with thin sheet metal casings of the compressor and the gas turbine to form a gas turbine engine assembly, comprising: 
 an isolator structure having a middle portion and pair of opposite end portions;    the structure have a curved shape forming a C or Z-shaped configuration;    the opposite end portions each having a fastening assembly for rigidly joining the combustor casing as well as either the compressor or gas turbine casing to form the rigid gas turbine engine assembly; and    the middle portion capable of movement relative to the end portions while thermally isolating the casings of the combustor, compressor and gas turbine.    
     
     
         9 . The thermal isolator device according to  claim 8 , wherein each fastening assembly comprises a flange member mounted on one end of the structure with a plurality of through openings extending through each flange portion to allow connecting members to extend through and join each flange portion with one of the adjacent casings.  
     
     
         10 . The thermal isolator device according to  claim 9 , wherein the structure has a generally cylindrical configuration with a length L and radius from a center line of the structure R selected so that the ratio of the length to the radius L/R is in the range of about 0.2 to 0.6  
     
     
         11 . The thermal isolator device according to claim θ, wherein middle portion of the structure includes a pair of leg portions forming an angle θ of between 0 to 10 degrees.  
     
     
         12 . The thermal isolator device according to  claim 8 , wherein the middle portion forms an angle θ with the horizon of between 0 and 5 degrees.  
     
     
         13 . The thermal isolator device according to  claim 8 , wherein the structure is formed of a nickel based metallic alloy having a thickness in the range of about 0.10 to 0.25 inches.  
     
     
         14 . A thermal isolator device for joining a thick combustor casing with both a gas turbine and a compressor each having casings of thin sheet metal to form a gas turbine engine, comprising: 
 an isolator structure rigidly attached to the combustor casing and either the compressor or turbine casing and having a curved C or Z-shaped confirmation, including a middle portion and a pair of oppositely disposed end portions;    wherein the middle portion is capable of movement relative to the end portions of the isolating structure to compensate for differences in thermal expansion of the combustor casing and either compressor or turbine casing.    
     
     
         15 . The thermal isolator device according to  claim 14 , wherein through openings extend through each of the end portions, allowing fasteners to extend through the openings and into attachment with an adjacently disposed casing.  
     
     
         16 . The thermal isolator device according to  claim 14 , wherein isolator structure is of a generally cylindrical shape with a length L and radius from a center line of the structure R selected to achieve a ratio in the range of about 0.2 to 0.6.  
     
     
         17 . The thermal isolator device according to  claim 14 , wherein the middle portion includes a pair of leg portions of uneven length, with the leg portions forming an angle θ of between about 0 and 10 degrees.  
     
     
         18 . The thermal isolator device according to  claim 14 , wherein the middle portion forms an angle θ with the horizon of between about 0 and 5 degrees.  
     
     
         19 . The thermal isolator device according to  claim 14 , wherein isolator structure is formed of a nickel based metallic alloy having a thickness in the range of about 0.1 and 0.25 inches.  
     
     
         20 . The thermal isolator device according to  claim 15 , wherein each of the end portions includes a flange having a plurality of the through openings circumferentially spaced from one another.  
     
     
         21 . A method of forming a gas turbine engine assembly, comprising the steps of: 
 positioning a thin-walled compressor upstream from a thick-walled industrial combustor;    positioning a thin-walled gas turbine downstream from the thick-walled combustor;    rigidly fastening a first, cylindrically-shaped isolator device to both the combustor casing and the compressor casing; and    rigidly fastening a second, cylindrically-shaped isolator device to both the combustor casing and the gas turbine casing, whereby the first and second isolator devices thermally isolate the combustor from the compressor and the turbine during operation of the gas turbine engine assembly, while maintaining engine alignment for all rotating components.    
     
     
         22 . The method of  claim 21 , including the step of rigidly attaching an outer diameter end portion of each isolator to the combustor casing and attaching an inner diameter end portion of each isolator to either the compressor or the gas turbine.