Patent Publication Number: US-2015078907-A1

Title: Turbomachine including a non-destructive fastener element for joining components

Description:
BACKGROUND OF THE INVENTION 
     The subject matter disclosed herein relates to the art of turbomachines and, more particularly, to a turbomachine including a non-destructive fastener element for joining components. 
     Gas turbomachines include a compressor portion linked to a turbine portion through a common compressor/turbine shaft and a combustor assembly. An inlet airflow is passed through an air intake toward the compressor portion. In the compressor portion, the inlet airflow is compressed through a number of sequential stages toward the combustor assembly. In the combustor assembly, the compressed airflow mixes with a fuel to form a combustible mixture. The combustible mixture is combusted in the combustor assembly to form hot gases. The hot gases are guided to the turbine portion through a transition piece. The hot gases expand through a number of turbine stages acting upon turbine buckets mounted on wheels to create work that is output, for example, to power a generator, a pump, or to provide power to a vehicle. 
     Each turbine stage may include a cover plate disposed about a central rotor that supports the buckets. The cover plates may reduce the effects of the hot gases on the central rotor and the buckets. Some cover plates may be shoe-horned into place about the central rotor. Other cover plates rely on in-field customization before mounting to the central rotor. Once installed, a fastener element, typically in the form of a pin, is passed through a base portion of each bucket to secure the cover plate to the rotor. The pin is often peened or staked in place to the base of the bucket. Removal of the pin may be both time and labor intensive resulting in undesirable down time for the turbomachine. 
     BRIEF DESCRIPTION OF THE INVENTION 
     According to one aspect of an exemplary embodiment, a turbomachine includes a first component including a first surface and a second surface spaced from the first surface by a gap. One of the first and second surfaces includes a non-destructive fastener element receiving opening and a wire retention feature. A second component extends into the gap between the first and second surfaces. A non-destructive fastener element is detachably mounted to the first component. The non-destructive fastener element includes a post member and a wire member operatively connected to the post member. The post member extends into the non-destructive fastener element receiving opening preventing removal of the second component and the wire member engages with the wire retention feature to secure the non-destructive fastener element to the first component. 
     According to another aspect of the exemplary embodiment, a turbomachine includes a rotor including a radial outer edge having a blade mounting region provided with a plurality of blade mounts disposed circumferentially about the radial outer edge, a first groove defining member extending about the radial outer edge and a second groove defining member extending circumferentially about the rotor radially inwardly of the plurality of blade mounts. A plurality of blades is mounted to the rotor. Each of the plurality of blades includes a retaining component and a blade mounting portion. The retaining component includes a first surface and the blade mounting portion includes a second surface spaced from the first surface by a gap. One of the first and second surfaces includes a non-destructive fastener element receiving opening and a wire retention feature. A blade retaining element is received by the first and second groove defining members and extends into the gap between the first and second surfaces. A non-destructive fastener element is detachably mounted to the retaining component. The non-destructive fastener element includes a post member and a wire member operatively connected to the post member. The post member extends into the non-destructive fastener element receiving opening preventing removal of the blade retaining component and the wire member engages with the wire retention feature to secure the non-destructive fastener element to the retaining component. 
     These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which: 
         FIG. 1  is a block diagram illustrating a turbomachine system including a turbomachine provided with a non-destructive fastener element, in accordance with an exemplary embodiment; 
         FIG. 2  is a partial cross-sectional view of a turbine portion having a turbine rotor having a segmented cover component joined to a blade through the non-destructive fastener element of  FIG. 1 ; 
         FIG. 3  is a partial perspective view of the turbine rotor of  FIG. 2 ; 
         FIG. 4  is a partial perspective view of a segmented cover component joined to a retaining component of the blade with a non-destructive fastener element, in accordance with an aspect of the exemplary embodiment; 
         FIG. 5  is a partial cross-sectional side view of the segmented cover component and retaining component of  FIG. 4 ; 
         FIG. 6  is a partial perspective view of a non-destructive fastener element joining a segmented cover component to a retaining component, in accordance with another aspect of the exemplary embodiment; 
         FIG. 7  is a perspective view of the segmented cover component positioned at the retaining component of  FIG. 6 ; 
         FIG. 8  is a perspective view of a non-destructive fastener element in accordance with another aspect of the exemplary embodiment; 
         FIG. 9  is a partial perspective view of the non-destructive fastener element of  FIG. 7  joining the segmented cover component to the retaining component of  FIG. 6 ; 
         FIG. 10  is a partial perspective view of a non-destructive fastener element joining the segmented cover component to a retaining component, in accordance with yet another aspect of the exemplary embodiment; 
         FIG. 11  is a perspective view of the segmented cover component positioned at the retaining component of  FIG. 10 ; 
         FIG. 12  is a perspective view of a non-destructive fastener element, in accordance with yet another aspect of the exemplary embodiment; 
         FIG. 13  is a partial cross-sectional side view of the segmented cover component and retaining component of  FIG. 12 ; 
         FIG. 14  is a perspective view of a non-destructive fastener element, in accordance with still yet another aspect of the exemplary embodiment; 
         FIG. 15  is a partial cross-sectional view of the non-destructive fastener element of  FIG. 14  securing a segmented cover component; 
         FIG. 16  is a perspective view of a non-destructive fastener element, in accordance with still another aspect of the exemplary embodiment; 
         FIG. 17  is a partial cross-sectional view of the non-destructive fastener element of  FIG. 16  securing a segmented cover component; 
         FIG. 18  is a perspective view of a non-destructive fastener element, in accordance with yet another aspect of the exemplary embodiment; and 
         FIG. 19  is a partial cross-sectional view of the non-destructive fastener element of  FIG. 18  securing a segmented cover component. 
     
    
    
     The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings. 
     DETAILED DESCRIPTION OF THE INVENTION 
     A turbomachine, in accordance with an exemplary embodiment, is indicated generally at  2  in  FIG. 1 . Turbomachine  2  includes a compressor portion  4  operatively connected to a turbine portion  6  through a combustor assembly  8 . Combustor assembly  8  includes one or more combustors  10  that may be arranged in a can-annular array. Compression portion  4  is also mechanically linked to turbine portion  6  through a common compressor/turbine shaft  12 . Compressor portion  4  includes an inlet  14  that may receive an ambient airflow. The airflow passes through, and is compressed by, compressor  4 . A portion of the airflow passes to combustor assembly  8  to mix with fuel to form a combustible mixture. Another portion of the airflow passing from compressor portion  4  passes into turbine portion  6  for cooling. The combustible mixture is combusted in combustor assembly  8  and passed into turbine portion  6  as hot gases. The hot gases expand through turbine portion  6  and exit through an exhaust portion  16 . Turbine portion  6  converts thermal energy from the hot gases to mechanical energy used to power a load  18 . Load  18  may be a generator, a pump or other driven device connected to shaft  12 . 
     Turbine portion  6  includes a turbine rotor  30  that supports a plurality of buckets or blade components  33 . Blade components  33 , when exposed to the hot gases flowing through turbine portion  6 , cause turbine rotor  30  to rotate. At this point, it should be understood that the number of turbine rotors may vary. As shown in  FIGS. 2 and 3 , turbine rotor  30  extends from a central hub  37  to a radial outer edge  39 . Radial outer edge  39  includes a blade mounting region  41  having a plurality of blade mounts  43  shown in the form of dovetail slots  45 . Turbine rotor  30  includes a plurality of first groove defining members, one of which is indicated at  48  forming a first groove  50  arranged about radial outer edge  39  and a second groove defining member  54  defining a second groove  56  arranged radially inwardly of blade mounting region  41 . 
     Each of the plurality of blade components  33  is coupled to turbine rotor  30  at corresponding ones of the plurality of blade mounts  43 . Each blade component  33  includes an airfoil portion  59  that extends from a blade mounting portion  61 . Blade mounting portion  61  is shown in the form of a dovetail member  63  that is received by dovetail slot  45 . Each blade component  33  also includes at least one retaining component  66  having an outer surface  69  that is generally parallel to, and spaced from, an outer surface  72  of blade mounting portion  61 . A second retaining component (not separately labeled) may also be provided. A gap  74  is formed between retaining component  66  and first outer surface  72  of blade mounting portion  61 . 
     One or more blade retaining elements,  80  is mounted to radial outer edge  39  and held in place, at least in part, by retaining component  66 . In accordance with an aspect of the exemplary embodiment, blade retaining element  80  takes the form of a plurality of segmented cover components, one of which is indicated at  81 . Of course it should be understood that blade retaining element  80  may also take the form of a locking wire. Each segmented cover component  81  includes a hook element  83  that engages with second groove defining member  54  and a radial outer lip  85  that is extends into gap  74  and is received by first groove  50 . Segmented cover components  80  may shield turbine rotor  30  from hot gases, may seal a coolant flow path, and may dampen vibrations, may axially retain blade components  33  or the like. Segmented cover component  81  is secured to turbine rotor  30  through a plurality of non-destructive fastener elements, one of which is indicated at  94  that extend through respective ones of retaining component  66  of each blade component  33 . 
     In accordance with one aspect of the exemplary embodiment illustrated in  FIGS. 4-5 , retaining component  66  includes a non-destructive fastener element receiving opening  96  and an adjacent wire retention feature  97 . Non-destructive fastener element  94  includes a post member  107  and a wire member  110 . At this point it should be understood that the term “non-destructive” describes a fastener element that may be installed without permanent deformation and removed without suffering irreparable damage so that subsequent re-use is possible. Post member  107  includes a central opening or wire receiving passage  113 . Wire member  110  extends from a first end  116  to a second end  117  through an intermediate portion  118 . First end  116  is received within wire receiving passage  113  and retained by post member  107 . Second end  117  is received by wire retaining feature  97  on retaining component  66 . Second end  117  includes a hook section  120  that snap-fittingly grips cover retaining component  66 . Once installed, post member  107  extends toward segmented cover component  81 . Radial outer lip  85  prevents segmented cover component  81  from being withdrawn when non-destructive fastener element  94  is installed, as shown in  FIG. 5 . Non-destructive fastener element  94  may be removed by simply deforming wire member  110  and releasing second end  117  from wire retaining feature  97 . 
     Reference will now follow to  FIGS. 6-9  in describing a non-destructive fastener element  130  in accordance with another aspect of the exemplary embodiment. In the exemplary embodiment shown, each blade component  33  includes a retaining component  133  having an outer surface  135 . Retaining component  133  includes a non-destructive fastener element receiving opening  138  having a lead-in feature  139  that facilitates insertion of non-destructive fastener element  130 . Retaining component  133  also includes a first wire retention feature  140  arranged on one side of non-destructive fastener element receiving opening  138  and a second wire retention feature  142  arranged on an opposing side of non-destructive fastener element receiving opening  138 . Each of the first and second wire retention features  140  and  142  includes a corresponding lead-in section  144  and  145 . 
     Non-destructive fastener element  130  includes a post member  154  having a base portion  156  and a post portion  158 . Base portion  156  includes a wire receiving passage  160  that extends generally perpendicularly to a longitudinal axis of post portion  158 . Base portion  156  also includes an access port  166  that bisects wire receiving passage  160 . A wire member  174  extends through wire receiving passage  160 . Access port  166  provides access for a tool, such as a drill bit, to sever wire member  174  in the event that removal is not easily/readily accomplished, as detailed below. Wire member  174  extends from a first end  176  to a second end  177  through an intermediate portion  178 . First end  176  includes a first hook section  180  and second end  177  includes a second hook section  181 . First and second ends  176 , 177  are configured to be snap-fittingly received by first and second wire retaining features  140  and  142 . First and second lead-in sections  144  and  145  facilitate insertion of first and second ends  176  and  177 . Once installed, post portion  158  extends toward segmented cover component  81 . Radial outer lip  85  prevents segmented cover component  81  from being withdrawn when non-destructive fastener element  130  is installed, as shown in  FIG. 5 . Non-destructive fastener element  130  may be removed by simply deforming wire member  174  and releasing first and second ends  176  and  177  from retaining component  133 . 
     Reference will now follow to  FIGS. 10-13  in describing a non-destructive fastener element  190  in accordance with yet another aspect of the exemplary embodiment. In the exemplary embodiment shown, blade component  33  includes a retaining component  193  having a first surface  195  and a projection  198 . Projection  198  juts out, or extends radially inwardly, toward shaft  12 . Of course it should be understood that projection  198  may be replaced by one or more recesses. Retaining component  193  also includes a non-destructive fastener element receiving opening  204  having a lead-in feature  205 . Non-destructive fastener element  190  includes a base portion  216  and a post portion  218 . Base portion  216  includes first and second wire receiving passages  221  and  223 . First wire receiving passage  221  extends along a first side of base portion  216  and second wire receiving passage  223  extends along a second, opposing side of base portion  216  and is generally parallel to first wire receiving passage  221 . 
     Non-destructive fastener element  190  also includes a wire member  230  coupled to base portion  216 . Wire member  230  extends from a first end  233  to a second end  234  through an intermediate portion  235 . First end  233  extends through first wire receiving passage  221  and second end  234  extends through second wire receiving passage  223  such that a loop  239  is formed in intermediate section  235 . With this arrangement, post portion  218  is passed through non-destructive fastener element receiving opening  204  and wire member  230  is flexed allowing loop  239  to pass over, and engage with, projection  198 . Post portion  218  extends toward segmented cover component  81  to prevent removal. 
     At this point it should be understood that the exemplary embodiment describes a non-destructive fastener element for joining turbomachine components. While described as retaining a segmented cover component, it should be understood that the non-destructive fastener element may be used to join other structures both static and rotating. Further, it should be understood that in addition to being used in a turbine portion, the non-destructive fastener element may be used in the combustor assembly and or the compressor portion or other areas of the turbomachine. Further, it should be understood that the shape of the non-destructive fastener element may vary.  FIGS. 14 and 15  illustrate a non-destructive fastener element  300 , in accordance with another aspect of the exemplary embodiment.  FIGS. 16 and 17  illustrate a non-destructive fastener element  304 , in accordance with yet another aspect of the exemplary embodiment.  FIGS. 18 and 19  illustrate a non-destructive fastener element  308 , in accordance with still yet another aspect of the exemplary embodiment 
     While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.