Abstract:
An attachment structure and ceramic matrix composite liner combination for a gas turbine engine has a ceramic matrix composite liner including plural flanges extending away from a face of said liner. The flanges have an opening and a bracket secured to the flanges by a securement member extending through the opening in the flange, and through an opening in the bracket. The flanges are secured to the securement member through at least one washer having a spherical face facing a spherical recess in the flanges.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    This application relates to a way of mounting a ceramic matrix composite liner to a support structure for use in a gas turbine engine. 
         [0002]    Gas turbine engines are known, and typically include a compressor compressing air and delivering it into a combustion section where it is mixed with fuel and ignited. Products of this combustion pass downstream over turbine rotors, driving them to rotate. The turbine rotors in turn drive compressor rotors. 
         [0003]    Downstream of the turbine rotors the products of combustion leave the engine through an exhaust nozzle. Liners are provided at the exhaust nozzle. The liners are often formed of a ceramic matrix composite material, and it has been difficult to adequately mount these liners in the past. Typically, flat washers have been utilized to secure arms on the liner to a hanger bracket, and with a bolt and pin connection. 
         [0004]    However, this connection has sometimes resulted in damage to the ceramic matrix composite liners. 
       SUMMARY OF THE INVENTION 
       [0005]    In a featured embodiment, an attachment structure and ceramic matrix composite liner combination for a gas turbine engine has a ceramic matrix composite liner including plural flanges extending away from a face of the liner. The flanges have an opening and a bracket secured to the flanges by a securement member extending through the opening in the flange, and through an opening in the bracket. The flanges are secured to the securement member through at least one washer having a spherical face facing a spherical recess in the flanges. 
         [0006]    In another embodiment according to the previous embodiment, an opening in the spherical washer through which the securement member extends has an inner bore which is more closely spaced from an outer periphery of the securement member than the outer periphery of the securement member is spaced from the opening in the flange. 
         [0007]    In another embodiment according to any of the previous embodiments, the securement member is one of a bolt or rivet. 
         [0008]    In another embodiment according to any of the previous embodiments, there are spherical washers on both of two sides of the flange. 
         [0009]    In another embodiment according to any of the previous embodiments, one of the spherical washers is positioned between an ear on the bracket and spherical recess in the flange, and there being a second spherical recess on the flange on an opposed one of the two sides of the flange. 
         [0010]    In another embodiment according to any of the previous embodiments, there are a plurality of brackets, and a plurality of flanges secured to the plurality of brackets. 
         [0011]    In another embodiment according to any of the previous embodiments, there are spherical washers on both of two sides of the flange. 
         [0012]    In another embodiment according to any of the previous embodiments, one of the spherical washers is positioned between an ear on the bracket and spherical recess in the flange. A second spherical recess is on an opposed one of the two sides of the flange. 
         [0013]    In another embodiment according to any of the previous embodiments, there are a plurality of brackets, and a plurality of flanges secured to the plurality of brackets. 
         [0014]    In another embodiment according to any of the previous embodiments, the hanger is to be attached to a support structure by a self-locking bolt and nut. A flanged washer is captured between the self-locking bolt and nut, and within an aperture in the hanger bracket. The flanged washer allows adjustment of the mount bracket relative to the support structure when the mount bracket is attached to the support structure. 
         [0015]    In another embodiment according to any of the previous embodiments, the liner is in a turbine exhaust nozzle. 
         [0016]    In another embodiment according to any of the previous embodiments, the liner is in an augmentor. 
         [0017]    In another featured embodiment, a gas turbine engine has a compressor, a combustion section, and a turbine. The compressor and turbine rotate about a central axis and a plurality of ceramic matrix composite liners, which are attached to support structure within the gas turbine engine. The liners include plural flanges extending away from a face of the liner which will face away from a chamber radially inward of the liner. The flanges have an opening, and a bracket secured to the flanges by a securement member extending through the opening in the flanges, and through an opening in the bracket. The flanges are secured to the securement member through at least one washer having a spherical face facing a spherical recess in the flanges. 
         [0018]    In another embodiment according to the previous embodiment, an opening in the spherical washer through which the securement member extends has an inner bore which is more closely received with an outer periphery of the member than the outer periphery of the securement member is spaced from the opening in the flange. 
         [0019]    In another embodiment according to any of the previous embodiments, the securement member is one of a bolt or rivet. 
         [0020]    In another embodiment according to any of the previous embodiments, there are spherical washers on both of two sides of the flange, with one of the spherical washers positioned between an ear on the bracket and flange. There is a second spherical recess on the flange on an opposed one of the two sides of the flange. 
         [0021]    In another embodiment according to any of the previous embodiments, there are a plurality of brackets, and a plurality of the flanges secured to the plurality of brackets. 
         [0022]    In another embodiment according to any of the previous embodiments, the hanger is be attached to the support structure by a self-locking bolt and nut. A flanged washer is captured between the self-locking bolt and nut, and within an aperture in the support structure, and an aperture in the hanger bracket. The flanged washer allows adjustment of the mount bracket relative to the support structure. 
         [0023]    In another embodiment according to any of the previous embodiments, the gas turbine engine includes an exhaust nozzle. The plurality of ceramic matrix composite liners are positioned in the exhaust nozzle. 
         [0024]    In another embodiment according to any of the previous embodiments, the gas turbine engine includes an augmentor. The plurality of ceramic matrix composite liners are positioned in the augmentor. 
         [0025]    These and other features may be best understood from the following drawings and specification. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]      FIG. 1A  schematically shows a gas turbine engine. 
           [0027]      FIG. 1B  shows another schematic gas turbine engine. 
           [0028]      FIG. 2  shows a detail of one mount bracket for mounting a liner to a support structure. 
           [0029]      FIG. 3  shows an alternative detail. 
           [0030]      FIG. 4  shows another feature. 
           [0031]      FIG. 5  shows the overall connection. 
       
    
    
     DETAILED DESCRIPTION 
       [0032]      FIG. 1A  schematically illustrates a gas turbine engine  20 . The gas turbine engine  20  is disclosed herein as a two-spool turbofan that generally incorporates a fan section  22 , a compressor section  24 , a combustor section  26  and a turbine section  28 . Alternative engines might include an augmentor section (not shown) among other systems or features. The fan section  22  drives air along a bypass flow path B in a bypass duct defined within a nacelle  15 , while the compressor section  24  drives air along a core flow path C for compression and communication into the combustor section  26  then expansion through the turbine section  28 . Although depicted as a turbofan gas turbine engine in the disclosed non-limiting embodiment, it should be understood that the concepts described herein are not limited to use with turbofans as the teachings may be applied to other types of turbine engines including three-spool architectures. 
         [0033]    The engine  20  generally includes a low speed spool  30  and a high speed spool  32  mounted for rotation about an engine central longitudinal axis A relative to an engine static structure  36  via several bearing systems  38 . It should be understood that various bearing systems  38  at various locations may alternatively or additionally be provided. 
         [0034]    The low speed spool  30  generally includes an inner shaft  40  that interconnects a fan  42 , a low pressure compressor  44  and a low pressure turbine  46 . The inner shaft  40  is connected to the fan  42  through a geared architecture  48  to drive the fan  42  at a lower speed than the low speed spool  30 . The high speed spool  32  includes an outer shaft  50  that interconnects a high pressure compressor  52  and high pressure turbine  54 . A combustor  56  is arranged between the high pressure compressor  52  and the high pressure turbine  54 . A mid-turbine frame  57  of the engine static structure  36  is arranged generally between the high pressure turbine  54  and the low pressure turbine  46 . The mid-turbine frame  57  further supports bearing systems  38  in the turbine section  28 . The inner shaft  40  and the outer shaft  50  are concentric and rotate via bearing systems  38  about the engine central longitudinal axis A which is collinear with their longitudinal axes. 
         [0035]    The core airflow is compressed by the low pressure compressor  44  then the high pressure compressor  52 , mixed and burned with fuel in the combustor  56 , then expanded over the high pressure turbine  54  and low pressure turbine  46 . The mid-turbine frame  57  includes airfoils  59  which are in the core airflow path. The turbines  46 ,  54  rotationally drive the respective low speed spool  30  and high speed spool  32  in response to the expansion. A turbine exhaust nozzle  19  receives the hot products of combustion downstream of the low pressure turbine  46 . 
         [0036]    Referring to  FIG. 1B , a gas turbine engine  10  may include a fan section  212 , a compressor section  214 , a combustor section  216 , and a turbine section  218 . Air entering into the fan section  212  is initially compressed and fed to the compressor section  214 . In the compressor section  214 , the incoming air from the fan section  212  is further compressed and communicated to the combustor section  216 . In the combustor section  216 , the compressed air is mixed with gas and ignited to generate a hot exhaust stream  228 . The hot exhaust stream  228  is expanded through the turbine section  218  to drive the fan section  212  and the compressor section  214 . In this example, the gas turbine engine  210  includes an augmenter section  220  where additional fuel can be mixed with the exhaust gasses  228  and ignited to generate additional thrust. The exhaust gasses  228  flow from the turbine section  218  and the augmenter section  220  through an exhaust liner assembly  222 . 
         [0037]      FIG. 2  shows a connection between a ceramic matrix composite liner  82 , and support or static structure  80  within the gas turbine engine. As shown, a self-locking bolt  88  and nut  90  capture a flanged washer  92 , and the support structure  80  to secure a mount bracket  84 . The mount bracket  84  has a central web  85  which is secured by the bolt  88 . The mount bracket  84  also has ears  86  extending radially inwardly towards the liner  82 . As will be understood, the liner  82  faces hot products of combustions in a chamber  400 . 
         [0038]    The liner  82  may be utilized in the turbine exit nozzle  19  as shown in  FIG. 1A , or as part of the augmentor section  220  in  FIG. 1B . The liners  82  may be utilized in other areas having a hot chamber  400 , but these two will be common examples. 
         [0039]    The liner  82  has flanges  96  extending away from the hot chamber  400 , and which are secured to the hanger bracket  84 . The flanges  96  extend away from a face of the liner  82  that faces away from the chamber  400 , radially inward of the liner  82 . As shown, bolts or pin rivets  100  extend through an opening  98  in the flange  96 , and a nut or collar  106  secures the bolt or rivet  100 . Spherical washers  102  are positioned on each axially side of the flange  96 . A clearance is provided between a radially outer portion of the bolt or rivet  100  and an inner portion of the hole  98 . Other securement members may be used at  100 . There is less of a clearance between an inner bore of the washers  102 , such that forces transmitted from the bolt or rivet  100  are transmitted into the washers  102 . 
         [0040]    Since the washers  102  have a spherical face  401  in contact with a spherical recess  403  in a face of the flange  96 , there is greater contact surface area. Thus, there is less stress on any portion of the surface of the flange  96 . Since these forces are transmitted over a larger surface area, and since there is less clearance between the washer  102  and the bolt or rivet  100  than there is between the inner surface of opening  98  of the flange  96 , the flange  96  is protected compared to the prior art. 
         [0041]      FIG. 3  shows an embodiment wherein the hanger ear  86  is not separated from the flange  96  by a washer, but there is a washer  108  on an opposed side. Again, there is a spherical surface  403  on the flange  96 , and a spherical face  41  on the washer  106 . 
         [0042]      FIG. 4  shows the bolt  88  secured with the flanged washer  92 , and the nut  90 , capturing the static structure  80  and hanger web  85 . The use of the flanged washer will allow adjustment for relative thermal growth between the hanger/bracket  84  and the support structure  80 . 
         [0043]      FIG. 5  shows that there are a plurality of the hanger/bracket  84  connecting the static or support structure  80  to the ceramic matrix composite liner  82 . 
         [0044]    Although an embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.