Abstract:
A system for use in limiting axial movement between a hanger and a fairing assembly within a turbine assembly is provided. The hanger includes an inner radial hanger bend portion that defines a hook channel therein. The fairing assembly includes an outer surface, a hook member extending from the outer surface to mate with the hook channel, and a circumferential groove defined in the outer surface such that at least a portion of the hanger bend portion is positioned between the circumferential groove and the hook member. The system includes a retention member sized for insertion into the circumferential groove, wherein the retention member is configured to extend from the circumferential groove and press against the hanger bend portion to facilitate maintaining the hook member within the hook channel.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a non-provisional application and claims priority to U.S. Provisional Patent Application Ser. No. 61/639,563 filed Apr. 27, 2012 for “TURBINE FRAME HANGER LOCK ASSEMBLY AND METHOD”, which is hereby incorporated by reference in its entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    This invention relates generally to gas turbine engines, and more specifically to turbine frame hanger lock assemblies and methods of assembling the same. 
         [0003]    At least some known gas turbine engines include a frame that supports a rotor assembly. For example, gas turbine engines may include one or more rotor shafts supported by bearings which, in turn, may be supported by generally annular engine frames. An engine frame may include a generally annular casing spaced radially outwardly from an annular hub, with a plurality of circumferentially spaced apart struts extending therebetween. In some frame applications it may be necessary to protect the struts with fairings that have higher temperature capability. Because temperature variances can cause metals to expand and contract, it is desirable to separate high temperature engine components such as the flow path components, from comparatively low temperature peripheral components such as the frame components. To attach flow path components to the frame components, one or more hangers are used. The hangers serve to attenuate heat transfer from flow path components to frame components. Primarily, these hangers serve to affix flow path components in predetermined positions relative to frame components. 
         [0004]    In some implementations, hangers are annular components with a curved cross-section. The outermost surface of the hangers contain apertures and are fastened (e.g., with bolts threaded through the apertures) to the frame of the turbine engine. The innermost surface of the hangers can be fastened to the flow path components, also utilizing apertures for receiving fasteners (e.g., bolts). In some cases, a single hanger may be used to attach a single flow path component to a frame component. In other cases, a single hanger may be used to attach multiple flow path components to a frame component. Each hanger conventionally requires a number of fasteners, adding a significant time burden to installation. Furthermore, the number of hangers and corresponding large quantity of fasteners contribute to the overall weight of the turbine engine. Even further, the use of bolts to attach hangers to various flow path and frame components inherently requires penetration of both the hangers and the respective components, increasing the potential for stress related failures in the gas turbine engine. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0005]    In one aspect, a system for use in limiting axial movement between a hanger and a fairing assembly within a turbine assembly is provided. The hanger includes an inner radial hanger bend portion that defines a hook channel therein. The fairing assembly includes an outer surface, a hook member extending from the outer surface to mate with the hook channel, and a circumferential groove defined in the outer surface such that at least a portion of the hanger bend portion is positioned between the circumferential groove and the hook member. The system includes a retention member sized for insertion into the circumferential groove, wherein the retention member is configured to extend from the circumferential groove and press against the hanger bend portion to facilitate maintaining the hook member within the hook channel. 
         [0006]    In another aspect, a turbine assembly is provided. The turbine assembly includes a hanger including an inner radial hanger bend portion that defines a hook channel therein and a fairing including an outer surface, a hook member extending from said outer surface to mate with said hook channel, and a groove defined in said outer surface such that a portion of said hanger bend portion is positioned between said groove and said hook member. The assembly also includes a retention member sized for insertion into said groove, wherein said retention member is configured to extend from said groove and press against said hanger bend portion to facilitate maintaining said hook member within said hook channel. 
         [0007]    In yet another aspect, a method of limiting axial movement between a hanger and a fairing within a turbine assembly is provided. The method includes extending a bend portion of the hanger to define a receiving channel therein, extending a hook member from an outer surface of the fairing to mate with the receiving channel, defining a groove in the outer surface such that at least a portion of the hanger bend portion is positioned between the groove and the hook member, inserting a retention member into the groove, and extending the retention member from the groove to press against the hanger bend portion of the hanger to facilitate maintaining the hook member within the receiving channel. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIGS. 1-20  show exemplary embodiments of the assembly and method described herein. 
           [0009]      FIG. 1  is a schematic perspective view of a turbine frame hanger and a collection of fairing sections (e.g., flow path components) according to an embodiment; 
           [0010]      FIG. 2  is a schematic perspective view of a turbine frame hanger as it is mounted to a collection of fairing sections according to an embodiment; 
           [0011]      FIG. 3  is a schematic cross-sectional view of a turbine frame hanger as it is mounted to a fairing section, according to an embodiment; 
           [0012]      FIG. 4  is a schematic cross-sectional view of a turbine frame hanger as it is mounted to a fairing section, according to an embodiment; 
           [0013]      FIG. 5  is a schematic cross-sectional view of a turbine frame hanger as it is mounted to a fairing section, according to an embodiment; 
           [0014]      FIG. 6  is a schematic cross-sectional view of a turbine frame hanger as it is mounted to a fairing section, according to an embodiment; 
           [0015]      FIG. 7  is a schematic cross-sectional view of a turbine frame hanger as it is mounted to a fairing section, illustrating a scalloped opening for receiving a retention member, according to an embodiment; 
           [0016]      FIG. 8  is a schematic cross-sectional view of a turbine frame hanger as it is mounted to a fairing section, illustrating a retention member inserted through a scalloped opening, according to an embodiment; 
           [0017]      FIG. 9  is a schematic perspective view of a turbine frame hanger as it is mounted to multiple fairing sections, illustrating a retention member inserted through a scalloped opening, according to an embodiment; 
           [0018]      FIG. 10  is a schematic perspective view of a turbine frame hanger as it is mounted to multiple fairing sections, illustrating a retention member inserted through a scalloped opening, according to an embodiment; 
           [0019]      FIG. 11  is a schematic perspective view of a multi-turn retention member, according to an embodiment; 
           [0020]      FIG. 12  is a schematic perspective view of multiple segmented retainers, according to an embodiment; 
           [0021]      FIG. 13  is a schematic perspective view of a single-layer, 360 degree retainer ring, according to an embodiment; 
           [0022]      FIG. 14  is a schematic perspective view illustrating a single sectioned retainer having a wavy region, according to an embodiment; 
           [0023]      FIG. 15  is a schematic perspective view of multiple fairings attached to a hanger utilizing both a single-layer, 360 degree retainer ring topped with a plurality of sectioned retainers having wavy regions, according to an embodiment; 
           [0024]      FIG. 16  is a schematic perspective view of multiple fairings attached to a hanger utilizing both a single-layer, 360 degree retainer ring topped with a plurality of sectioned retainers having wavy regions, according to an embodiment; 
           [0025]      FIG. 17  is a schematic perspective view of a segmented retainer having a wavy region, according to an embodiment; 
           [0026]      FIG. 18  is a schematic perspective view of the wavy region of a segmented retainer, according to an embodiment; 
           [0027]      FIGS. 19   a  through  19   d  illustrate various configurations of retention members for retaining a hanger to a plurality of fairings, according to an embodiment; and 
           [0028]      FIG. 20  shows an exemplary tool for installing and removing the retention members shown in  FIGS. 19   a  through  19   d.    
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0029]      FIG. 1  is a schematic perspective view of a hanger  100  positioned to abut a front end  102  of a collection of fairings  104  aligned in a circular fashion. The illustrated hanger  100  is shown with a plurality of apertures  106  extending through a front flange  108  for attaching the hanger  100  to a frame  110  of a turbine engine. As shown in  FIG. 2 , the hanger arm  112  of the hanger  100  has a hook channel  114  having a substantially j-shaped cross section, for receiving a fairing circumferential hook  116  of a fairing  104 . About a bend portion  118  of the hanger arm  112  is located an annular flat surface  120  that lines up vertically with a fairing circumferential retainer groove  122  in the fairing  104  when the hanger  100  is positioned as shown, such that the hook channel  114  of the hanger  100  is mated with the circumferential hook  116  of the fairing  104 . The retainer groove  122  is for receiving an axial retention member  124 , which may be a continuous ring with a single break in it, a continuous ring that substantially comprises a spiral having multiple rotations, a series of segmented retainers, and combinations thereof. The retention member  124  is placed in the retainer groove  122  so that the retention member  124  prevents the fore and aft movement of the fairing  104 , and the retention member  124  thereby prevents the hook channel  114  of the hanger  100  from separating from the circumferential hook  116  of the fairing  104 . Although a fairing  104  is shown as the flow path component in these exemplary embodiments, it should be recognized by one skilled in the art that any flow path component could take the place of the fairing  104 . 
         [0030]    As shown in  FIG. 3 , mechanical entrapment of the hook channel  114  in the circumferential hook  116  of the fairing  104  is accomplished by placing the retention member  124  in the retainer groove  122 . A c-clip  126  is then installed adjacent the retention member  124 , wherein the c-clip  126  has a horizontal tab  128  extending away from the rear of the c-clip  126 . When the c-clip  126  is fully engaged, the horizontal tab  128  is positioned to abut an outer surface  130  of the retention member  124  to facilitate restricting movement of retention member  124  within the retainer groove  122 . 
         [0031]      FIG. 4  illustrates an embodiment of the retention member  124  as described above, locked into a circumferential retainer groove  122  in a fairing  104 . The retention member  124  shown is a single ply ring, having a fore to aft thickness slightly less than the fore to aft distance between the vertical walls of the circumferential retainer groove  122 . 
         [0032]      FIGS. 5 and 6  illustrate another embodiment of a turbine frame hanger lock assembly  10 . In this embodiment, the retention member  124  is a double ply, spiral ring, having a 720 degree circumference. A hanger located circumferential retainer groove  132  is provided by extending the hanger  100  about the bend portion  118  of the hanger arm  112 , so that the channel of the hanger located circumferential retainer groove  132  substantially mates with the channel  123  of the circumferential retainer groove  122  in the fairings  104 . 
         [0033]      FIGS. 7 through 10  illustrate a scalloped opening  134  in the forward side  136  of the hook channel  114  and the forward side  138  of the fairing.  FIG. 9  illustrates the scalloped opening  134  and shows that the opening  134  has a predetermined width for receiving a first end  140  of a multi-turn retention member  142 . The first end  140  of the multi-turn retention member  142  is inserted into the scalloped opening  134  and the multi-turn retention member  142  is fed around the circumference of the hanger  100 , such that the retention member  124  is traveling in an enclosed groove  144 . A second end  146  of the ring has a loop that prevents further insertion of the multi-turn ring  142  into the enclosed groove  144 . 
         [0034]    As shown in  FIG. 10 , the loop of the second end  146  is configured to be less than the width of the scalloped opening  134  so that the loop can be contained within the scalloped opening  134  when the multi-turn retention member  142  is fully inserted into the enclosed groove  144 .  FIG. 11  illustrates the configuration of the multi-turn retention member  142  having a spiral shape. 
         [0035]      FIGS. 12 and 13  illustrate a hybrid retaining ring configuration including a first retaining ring  147  (as shown in  FIG. 13 ) that extends one full circumference (approximately 360 degrees) around the enclosed groove  144 . A bent portion  150  at one end of the first retaining ring  147  prevents the ring from being inserted too far into the enclosed groove  144  and facilitates removal of the first retaining ring  147  therefrom. A second set of segmented retainers  148  (as shown in  FIG. 12 ) is then installed on top of the first retaining ring  147 , such that each of the set of segmented retainers  148  extends around less than the full circumference of the channel. As illustrated in  FIG. 12 , each of the set of segmented retainers  148  extend a fraction of the circumference of the enclosed groove  144 . 
         [0036]    As shown in  FIG. 14 , each of the set of segmented retainers  148  can have a wavy region  152  (e.g., an axial wave) in them to axially preload the contents of the enclosed groove  144 . In this case, the first retainer ring  147  is formed without wavy regions such that the first retainer ring  147  is substantially planar in the plane perpendicular to the axis around which the ring  147  extends. According to an embodiment, each segmented retainer  148  may include a ring layer  154  having a wavy region  152  positioned thereon. A spring clip  156  may be attached to one end of the ring layer  154  for preventing rigid body motion (e.g., circumferential motion). Finally, a spacer  158  is configured to attach the spring clip  156  to a top surface of the ring layer  154 . According to another embodiment, each segmented retainer  148  may include a layer  154  having a wavy region  152 , and an integrated spring clip  160 . 
         [0037]    In one embodiment, the sets of segmented retainers  148  is inserted into the channel as shown in  FIGS. 15 and 16 , through the scalloped openings  134 , such that each segmented retainer  148  with a wavy region  152  axially preloads the channel, preventing axial (e.g., fore and aft) movement of the first retaining ring  147  and each of the segmented retainers  148 . The interface between the hanger  100  and the fairings  104  forms the scalloped openings  134  such that there is one scalloped opening  134  formed when two fairings  104  are placed side-by-side and a hanger  100  is positioned adjacent the fairings  104 , as shown in  FIG. 15 . The wavy region  152  of each of the set of segmented retainers  148  is illustrated in  FIGS. 17 and 18 . 
         [0038]      FIGS. 19   a  through  19   d  illustrate various alternative configurations for retention members. In  FIG. 19   d , the continuous multi-turn retention member  124  is illustrated. 
         [0039]      FIG. 19   a  illustrates a hybrid retention member configuration including a first retention member  162  that extends one full circumference around the channel, and a second set of segmented retainers  164  that are inserted through scalloped openings  134  adjacent the first retention member  162 , such that each of the retention members  164  extend one quarter of the circumference of the hanger  100 . 
         [0040]      FIG. 19   b  illustrates a ring configuration including sixteen ring portions  166  that each extend one-sixteenth of the circumference of the hanger  100 . Each ring portion  166  is inserted through a scalloped opening  134  to extend within the enclosed groove  144  until the loop  168  prevents further insertion. 
         [0041]      FIG. 19   c  illustrates a retention configuration including four retention member portions  170  that each extend one-fourth of the circumference of the hanger  100 . Each retention member portion  170  is inserted through a scalloped opening  134  to extend within the enclosed groove  144  until the loop  172  prevents further insertion. 
         [0042]      FIG. 20  shows an X-shaped tool  174  for installing and removing a retention member  124  or segmented retainer. The X-shaped tool  174  has four advancing pins  176  for insertion into apertures  178  in the retention member  124  or segmented retainer. During installation of the retention member  124  or segmented retainer, a portion of the retention member  124  or segmented retainer is bent in the direction opposite the scalloped opening, until the retention member  124  or segmented retainer is fully installed in the scalloped opening. Because of this bend in the retention member  124  or segmented retainer, an advancing pin  176  of the X-shaped tool  174  can be inserted into a given aperture so that the X-shaped tool  174  is rotated in a counter clockwise manner, pushing the retention member  124  or segmented retainer into the scalloped opening. When a downstream aperture is nearly inserted into the scalloped opening, another of the advancing pins  176  engages an upstream aperture to continue installation. Once the entire retention member  124  or segmented retainer is inserted into the scalloped opening, the X-shaped tool  174  is removed. By reversing the direction of rotation of the X-shaped tool  174 , a retention member  124  or segmented retainer can be removed from the scalloped opening. 
         [0043]    Exemplary embodiments of a turbine hanger lock assembly and methods of assembling the turbine hanger lock assembly are described above in detail. The assembly and method are not limited to the specific embodiments described herein, but rather, components of the assembly and/or steps of the method may be utilized independently and separately from other components and/or steps described herein. Further, the described assembly components and/or the method steps can also be defined in, or used in combination with, other assemblies and/or methods, and are not limited to practice with only the assembly and/or method as described herein. 
         [0044]    This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to make and use the invention. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.