Abstract:
One embodiment is an apparatus comprising a first rotational gas turbine engine component including first threads; a second rotational gas turbine engine component including second threads; the first threads and the second threads being mated; and the first rotational engine component being fastened to the second rotational engine component substantially only by the first threads and the second threads being mated. Other embodiments include unique apparatuses, systems, devices, and methods relating to gas turbine engine interconnection. Further exemplary embodiments, forms, objects, features, advantages, aspects, and benefits of the present invention are included in the following description, drawings, and claims.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims the benefit of U.S. Provisional Patent Application 61/204,040, filed Dec. 31, 2008, and is incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The technical field relates generally to gas turbine engines and more particularly to apparatuses, systems, and methods of gas turbine engine component interconnection. 
       BACKGROUND 
       [0003]    Gas turbine engines are an efficient source of energy and have proven useful to propel and power aircraft, for electricity generation, as well as for other uses. One aspect of gas turbine engines is that they include structures, systems, subsystems, parts, pieces, and other components which must be interconnected. Presently, apparatuses, systems and methods of gas turbine engine component interconnection often suffer from a number of disadvantages, limitations, and drawbacks, for example, those respecting weight, mass, complexity, ease of assembly or disassembly, part count, engine envelope, engine profile, and others. Thus, there is a need for the unique and inventive apparatuses, systems, and methods of gas turbine engine component interconnection. 
       SUMMARY 
       [0004]    One embodiment is a unique apparatus for gas turbine engine component interconnection. Other embodiments include unique apparatuses, systems, methods, and combinations of these and/or other aspects relating to gas turbine engines. Further embodiments, forms, objects, features, advantages, aspects, and benefits shall become apparent from the following description and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  is a schematic diagram of a gas turbine engine. 
           [0006]      FIG. 2  is an illustrative view of interconnected gas turbine engine disks. 
           [0007]      FIG. 3  is an illustrative view of several interconnected gas turbine engine components. 
           [0008]      FIG. 4  is an illustrative view of interconnected gas turbine engine components including a lead in pilot. 
           [0009]      FIG. 5  is an illustrative view of interconnected gas turbine engine components including a lead in pilot. 
           [0010]      FIG. 6  is an illustrative view of interconnected shafts of a gas turbine engine. 
       
    
    
     DETAILED DESCRIPTION 
       [0011]    For purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates. 
         [0012]    With reference to  FIG. 1 , there is illustrated a schematic representation of a gas turbine engine  10 , which includes a fan section  12 , a compressor section  14 , a combustor section  16 , and a turbine section  18  which are integrated together to provide an aircraft flight propulsion engine. This type of gas turbine engine is generally referred to as a turbo-fan. One alternate form of a gas turbine engine includes a compressor section, a combustor section and a turbine section which have been integrated together to produce an aircraft flight propulsion engine without the fan section. As used herein, the term aircraft includes helicopters, airplanes, missiles, spacecraft, unmanned space devices and any other substantially similar devices. 
         [0013]    The compressor section  14  includes a rotor disk  20  having a plurality of compressor blades  22  coupled thereto. The rotor disk  20  is affixed to a shaft  24  that is rotatable within the gas turbine engine  10 . A plurality of compressor vanes  26  are positioned within the compressor section  14  to direct the fluid flow relative to blades  22 . Turbine section  18  includes a plurality of turbine blades  28  that are coupled to a rotor disk  30 . The rotor disk  30  is affixed to the shaft  24 , which is rotatable within the gas turbine engine  10 . Energy extracted in the turbine section  18  from the hot gas exiting the combustor section  16  is transmitted through shaft  24  to drive the compressor section  14 . Further, a plurality of turbine vanes  32  are positioned within the turbine section  18  to direct the hot gaseous flow stream exiting the combustor section  16 . 
         [0014]    As illustrated in the turbo-fan embodiment of  FIG. 1 , the turbine section  18  provides power to a fan shaft  34 , which drives the fan section  12 . The fan section  12  includes a fan  36  having a plurality of fan blades  38 . Air enters the gas turbine engine  10  in the direction of arrows A and passes through the fan section  12  into the compressor section  14  and a bypass duct  40 . 
         [0015]    It is important to realize that there are multitudes of gas turbine engine configurations and types. For example, additional compressors and turbines could be added with intercoolers connecting between the compressors, reheat combustion chambers could be added between the turbines, and multiple compressor and turbine stages could be present. Furthermore, in addition to aircraft propulsion applications, gas turbine engines can be used for industrial applications, such as pumping sets for gas and oil transmission lines, electricity generation, and naval propulsion, to name a few examples. Apparatuses, systems and methods of component interconnection are applicable to all types of gas turbine engines and are not limited the exemplary embodiments shown and described herein. It should also be appreciated that the exemplary embodiments described herein include a number of rotational engine elements including, for example, shafts, disks, blades, compressor components, turbine components, gears, and fans, to name a few examples. Various embodiments of gas turbine engine component interconnection may include fewer or greater numbers of components, including as many as a complete gas turbine engine, or as few as two gas turbine engine components. 
         [0016]    With reference to  FIG. 2  there is an illustrative view of interconnected gas turbine engine compressor disks  200 . Disk  210  includes exterior circumferential surface  211  with blades  212  extending therefrom, and disk  220  includes exterior circumferential surface  221  with blades  222  extending therefrom. Blades  212  are illustrated generically and could have a variety of angles, contours, designs, dimensions, geometries, shapes, sizes and other properties as would occur to those skilled in the art. This is also true of blades  222  which could have the same, similar or different characteristics as blades  212 . During gas turbine engine operation disks  210  and  220  rotate about an axis illustrated as dashed line X. 
         [0017]    As illustrated in  FIG. 2 , threaded interconnection  230  interconnects disks  210  and  220 . Interconnection  230  is formed by the mating of threads  231  of member  215  and threads  232  of member  225 . The mating of threads  231  and  232  alone is sufficient to maintain the interconnection of disks  210  and  220  during engine operation. Threads  231  and  232  can also be unmated to permit decoupling and separation of disks  210  and  220 , for example, for maintenance, repair, or replacement of various gas turbine engine components. In one embodiment threads  231  and  232  are buttress threads; however, various embodiments contemplate the use of triangular threads, trapezoidal threads, single loading threads, dual loading threads, acme threads, witworth threads, as well as a variety of other threads, as well as combinations and variations of the foregoing. It is also contemplated, regardless of the particular thread configuration used, that the threads can be coated, partially coated, substantially coated, uncoated, partially uncoated, or substantially uncoated. Furthermore, it is contemplated that a variety of thread adhesives, sealants, lubricants, coatings, and curing agents could be used in connection with any of the foregoing threads. 
         [0018]    With reference to  FIG. 3  there is shown one example of a gas turbine engine component assembly  300 . Assembly  300  includes disks  310  and  320 , and shaft  330 . Disks  310  and  320  are interconnected by the mating of threads  312  and  322 , and disk  320  and shaft  330  are interconnected by the mating of threads  323  and  332 . These threads can include any of the types, configurations, variations, coatings and other thread features or properties mentioned above in connection with  FIG. 2 , and the same is also true of the other threads disclosed herein. 
         [0019]    Also, as illustrated in  FIG. 3 , shaft  330  and compressor disk  320  include lead in pilots  334  and  324 . Lead in pilots can facilitate mating of threads and interconnection of components by guiding components during interconnection. For example, angle α of lead in pilot  334  provides guidance for shaft  330  as it is introduced into disk  320  which helps to align threads  323  and  332  and facilitate their ability to mate. Lead in pilots can and also provide abutment between opposing surfaces, for example, lead in pilot  334  abuts opposing surface  321  when threads  323  and  332  are substantially completely mated. Similarly lead in pilot  324  abuts opposing surface  314  when threads  312  and  322  are substantially completely mated. 
         [0020]    It should also be appreciated that various abutment configurations can provide a variety of additional features. For example, various abutment configurations can provide at least a partial seal between abutting structures, can stabilize abutting structures relative to one another, can provide some coupling of abutting structures, for example, due to friction or other forces between abutting structures, and can also provide force transfer between abutting structures. Nevertheless, it should be understood that even in embodiments which include each of the foregoing abutment features, the mating of threads alone is what maintains interconnection of engine components. Thus, even where lead in pilots  324  and  334  provide for abutment including all of the foregoing features, the mating of threads  312  and  332  is all that interconnects disks  310  and  320  and the mating of threads  323  and  332  is substantially all that interconnects disk  320  and shaft  330 . 
         [0021]    While  FIG. 3  illustrates one interconnection of compressor disks  310  and  320  and a shaft  330 , a variety of other interconnections are contemplated. For example, greater or fewer numbers of compressor disks could be used. Furthermore, greater numbers of shafts or other structure intermediate compression disks could be used. A variety of additional interconnections including interconnection of various components, structures, elements, and features noted above, and others are also contemplated. 
         [0022]    With reference to  FIG. 4  there is shown assembly  400  in which rotatable elements  410  and  420  are interconnected by a pair of mating threads  412  and  422 . These threads can include any of the types, configurations, variations, coatings and other features mentioned above in connection with  FIG. 2 . Elements  410  and  420  could be, for example, shafts, disks, other structures, or combinations of such structures. Element  410  includes a lead in pilot  412  which could have any of the features mentioned above. During engine operation, assembly  400  rotates in the direction indicated by Arrow RT-400. In this case, it is preferable for the treads  412  and  422  to tend to engage under such rotational conditions. Thus, during at least one state of operation, preferable the state inducing greatest or substantial force on the threaded interconnection, elements  410  and  420  tend toward engagement and not disengagement. In other embodiments the thread direction can be reversed. Furthermore, as mentioned above, threads  412  and  422  can also be dual loading or two way threads, which tend to engage regardless of the direction of rotation. 
         [0023]    With reference to  FIG. 5  there is shown assembly  500  which includes structures similar to assembly  400  as indicated by similar reference numerals incremental by 100. Additionally, assembly  500  includes abutment face  530  for contacting the opposite face of element  520 . Abutment face  530  can include all of the abutment features mentioned above. 
         [0024]    With reference to  FIG. 6  there are shown interconnected rotational shafts  600  of a gas turbine engine. A first shaft  610  includes threads  610  and a second shaft  620  includes threads  621 . Threads  611  and  621  are interconnected such that this interconnection alone is sufficient to maintain the interconnection of shafts  610  and  620  during engine operation. 
         [0025]    While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiments have been shown and described and that all changes and modifications that come within the spirit of the inventions are desired to be protected. It should be understood that while the use of words such as preferable, preferably, preferred or more preferred utilized in the description above indicate that the feature so described may be more desirable, it nonetheless may not be necessary and embodiments lacking the same may be contemplated as within the scope of the invention, the scope being defined by the claims that follow. In reading the claims, it is intended that when words such as “a,” “an,” “at least one,” or “at least one portion” are used there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. When the language “at least a portion” and/or “a portion” is used the item can include a portion and/or the entire item unless specifically stated to the contrary.