Abstract:
An exemplary method of adjustably mounting a first component to a second component includes, among other things, securing the first component to the second component with a linking member, and selectively adjusting the temperature of a variable portion of the linking member to change a size of the linking member.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a divisional of U.S. patent application Ser. No. 13/157284, which was filed on 9 Jun. 2011 and is incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    This disclosure relates generally to securing components and, more particularly, to securing components that have different coefficients of thermal expansion. 
         [0003]    As known, components having different coefficients of thermal expansion will expand and contract at different rates in response to temperature fluctuations. Securing components having different coefficients of thermal expansion is often difficult because the attachment strategy must accommodate the different rates of expansion and contraction. 
         [0004]    The high temperature environment of an aircraft includes many components having different coefficients of thermal expansion. These components often need to be secured to each other. For example, some aircraft include a trailing edge assembly that is secured to a metallic airframe bracket. The trailing edge assembly is typically made of a ceramic matrix composite material, which has a lower coefficient of thermal expansion than the, typically metallic, airframe bracket. As can be appreciated, securing such a trailing edge assembly to the airframe bracket is difficult due, in part, to the growth and retraction of the trailing edge assembly relative to the airframe brackets. 
         [0005]    The different rates of expansion and contraction between the trailing edge assembly and the airframe brackets have been accommodated by introducing slotted holes and flexures into the attachment strategy. These features offer limited positional precision, limited vibration resistance, and may not provide a rigid attachment. 
       SUMMARY 
       [0006]    A method of adjustably mounting a first component to a second component having a different coefficient of thermal expansion than the first component according to an exemplary embodiment of the present disclosure includes, among other things, securing the components together with a linking member. The method selectively adjusts the temperature of a variable portion of the linking member to change the size of the linking member. 
         [0007]    In a further non-limiting embodiment of the foregoing method, the method includes selectively adjusting by heating the variable portion 
         [0008]    In a further non-limiting embodiment of any of the foregoing methods, the method includes heating the variable portion using a heat tape. 
         [0009]    In a further non-limiting embodiment of any of the foregoing methods, the method includes adjusting by cooling the variable portion. 
         [0010]    In a further non-limiting embodiment of any of the foregoing methods, the method includes cooling the variable portion using a cooling fluid. 
         [0011]    In a further non-limiting embodiment of any of the foregoing methods, the method includes selectively adjusting by cooling the variable portion using a cooling fluid. 
         [0012]    In a further non-limiting embodiment of any of the foregoing methods, the method includes selectively adjusting the temperature of the variable portion using a fluid. 
         [0013]    In a further non-limiting embodiment of any of the foregoing methods, the variable portion has a higher coefficient of thermal expansion than the portions of the linking member securing the linking member to the first component and the portions of the linking member securing the linking member to the second component. 
         [0014]    In a further non-limiting embodiment of any of the foregoing methods, the first component has a different coefficient of thermal expansion than the second component. 
         [0015]    In a further non-limiting embodiment of any of the foregoing methods, the method includes mixing a first fluid with a second fluid to provide a mixed fluid and selectively adjusting the temperature of the variable portion using the mixed fluid, wherein the first fluid is hotter than the second fluid. 
         [0016]    In a further non-limiting embodiment of any of the foregoing methods, the method includes using a valve to selectively permit communication of a fluid to a position near the variable portion to vary a length of the linking member. 
         [0017]    In a further non-limiting embodiment of any of the foregoing methods, the valve is configured to permit communication of a fluid at a first temperature to the position to change the length in a first direction, and further configure to permit communication of a fluid at a second temperature to the position to vary the length in a second direction, the first temperature greater than the second temperature. 
         [0018]    In a further non-limiting embodiment of any of the foregoing methods, the fluid at the first temperature comprises air heated by a turbomachine. 
         [0019]    In a further non-limiting embodiment of any of the foregoing methods, the fluid at the second temperature comprises bleed air from a turbomachine. 
         [0020]    In a further non-limiting embodiment of any of the foregoing methods, the variable portion couples a first attachment portion to a second attachment portion, the first attachment portion configured to connect a linking member to the first component, a second attachment portion configured to connect the linking member to the second component, wherein heating the variable portion varies a distance between the first attachment portion and the second attachment portion in a first direction, and cooling the variable portion varies the distance between the first attachment portion and the second attachment portion in a second direction when cooled, the first direction opposite the second direction. 
         [0021]    In a further non-limiting embodiment of any of the foregoing methods, the method includes connecting a radially outer tube to both the variable portion and the first attachment portion, and connecting a radially inner tube to both the variable portion and the second attachment portion, the radially inner tube at least partially received within the radially outer tube, the variable portion being a component that is separate and distinct from both the radially outer tube and the radially inner tube. 
         [0022]    In a further non-limiting embodiment of any of the foregoing methods, the method includes using a valve to selectively permit communication of a fluid to a position radially between the outer tube and the variable portion to vary the distance. 
         [0023]    In a further non-limiting embodiment of any of the foregoing methods, the variable portion has a higher coefficient of thermal expansion than both the first attachment portion and the second attachment portion. 
         [0024]    In a further non-limiting embodiment of any of the foregoing methods, the first component has a coefficient of thermal expansion that is different than the coefficient of thermal expansion of the second component. 
         [0025]    In a further non-limiting embodiment of any of the foregoing methods, the first component is a ceramic matrix composite component, and the second component has a higher coefficient of thermal expansion than the first component. 
         [0026]    In a further non-limiting embodiment of any of the foregoing methods, the first component or the second component is trailing edge assembly of an aircraft, and the other of the first component or the second component is a metal airframe structure of the aircraft. 
     
    
     
       DESCRIPTION OF THE FIGURES 
         [0027]    The various features and advantages of the disclosed examples will become apparent to those skilled in the art from the detailed description. The figures that accompany the detailed description can be briefly described as follows: 
           [0028]      FIG. 1  shows a perspective view of a trailing edge assembly of an aircraft. 
           [0029]      FIG. 2  shows an end view of the  FIG. 1  trailing edge structure and a mounting assembly. 
           [0030]      FIG. 3  is a section view at line  3 - 3  in  FIG. 1  showing the trailing edge assembly in an assembled position. 
           [0031]      FIG. 4  is a section view at line  3 - 3  in  FIG. 1  showing the trailing edge assembly in an unassembled position. 
           [0032]      FIG. 5  is a section view of a linking member of the  FIG. 2  mounting assembly. 
           [0033]      FIG. 6  is a section view of another example linking member suitable for use in the  FIG. 2  mounting assembly. 
       
    
    
     DETAILED DESCRIPTION 
       [0034]    Referring to  FIGS. 1-4 , in this example, an aircraft  10  includes a first component and a second component. The first component is a trailing edge assembly  12 . The second component is an airframe structure  14 . 
         [0035]    The example trailing edge assembly  12  includes an outer shell  16  and ribs  18  spanning opposing walls of the outer shell  16 . A mounting assembly  20  is secured to the ribs  18  to connect the trailing edge assembly  12  to the airframe structure  14 . In this example, the mounting assembly  20  includes a plurality of linking members  22 . Each of the linking members  22  extends between a first attachment portion  24  and a second attachment portion  26 . The first attachment portion  24  is secured to the ribs  18 , and the second attachment portion  26  is secured to the mounting assembly  20 . 
         [0036]    The first attachment portions  24  of the example linking members  22  are secured directly to the ribs  18  with fasteners  32 . The second attachment portions  26  of the linking members  22  are secured to a bracket  28  with fasteners  30 , which is fastened directly to the airframe structure  14  with a plurality of fasteners  31 . In another example, the second attachment portions  26  are secured directly to the airframe structure  14  with the fasteners  30 . 
         [0037]    The trailing edge assembly  12  and the airframe structure  14  have different coefficients of thermal expansion. Thus, as the trailing edge assembly  12  and the airframe structure  14  are heated, the trailing edge assembly  12  changes length at a different rate than the airframe structure  14 . In one example, the trailing edge assembly  12  is a ceramic matrix composite component, and the airframe structure  14  is a metallic material. 
         [0038]    The adjustable linking members  22  of the mounting assembly  20  accommodate the different rates of thermal expansion and contraction. Accommodating these differences limits contact between the trailing edge assembly  12  and the airframe structure  14  particularly at interfaces between the two components such as the interfaces  34 . Undesirable contact can damage the trailing edge assembly  12 , for example. Accommodating these differences also controls the size of gaps at the interfaces  34 . 
         [0039]    Referring now to  FIG. 5  with continuing reference to  FIGS. 2-4 , in this example, the adjustable linking members  22  each include a variable portion  36 . The variable portion  36  is made of a material having a higher coefficient of thermal expansion than the first attachment portion  24  and the second attachment portion  26 . In one example, the variable portion  36  is made of an aluminum or steel material, and the first attachment portion  24  and the second attachment portion  26  are both made of a graphite or titanium material. The materials need not be metallic. 
         [0040]    Heating the variable portion  36  causes the variable portion  36  to expand, and particularly along the axis A. This expansion of the variable portion  36  moves the first attachment portion  24  away from the second portion  26  in a first direction along the axis A. Expanding the variable portion  36  increases the axial length of the adjustable linking member  22 . 
         [0041]    In this pneumatic example, a heating fluid, such as hot air, is used to heat the variable portion  36 . The heating fluid is communicated from a hot fluid supply  38  through an adjustable valve  40  to a fluid communication path  42  radially outside the variable portion  36 . The heating fluid is then vented from the adjustable linking member  22  at a vent location  44 . The valve  40  controls the extension of the variable portion  36  by controlling the flow of heating fluid to the fluid communication path  42  to heat the variable potion  36 . 
         [0042]    In this example, the valve  40  is moveable to a position that communicates a cooling fluid from a cold fluid supply  46  into the fluid communication path  42 . Cooling the variable portion  36  causes the variable portion  36  to retract in a second direction opposite the first direction. Retracting the variable portion  36  decreases the axial length of the linking member  22 . 
         [0043]    In one example, the hot fluid supply  38  is air that has been heated by a turbomachine of the aircraft  10 , and the cold fluid supply  46  is ambient air such as bleed air. Other examples may use fluids other than air, and other sources of heating and cooling. 
         [0044]    As can be appreciated, the valve  40  may mix the heating fluid with the cooling fluid to adjust the temperature of the fluid entering the fluid communication path  42 . A person having skill in this art and the benefit of this disclosure would understand how to design a suitable valve  40 . 
         [0045]    In some examples, the cooling fluid is not used. In these examples, the variable portion  36  is not actively cooled. 
         [0046]    When the trailing edge assembly  12  and the airframe structure  14  are expanding at different rates due to an increase in temperature, an operator may initiate extension of the adjustable linking member  22  by increasing the flow of hot fluid from the hot fluid supply  38 . A controller  47  may be used to initiate movement of the valve  40 , for example. Extending the adjustable linking member  22  increases the distance between the trailing edge assembly  12  and the airframe structure  14  to prevent damage to the trailing edge assembly  12  due to contact with the airframe structure  14  as the trailing edge assembly  12  grows relative to the airframe structure  14 . 
         [0047]    In this example, the adjustable linking member  22  includes an inner tube  48  and an outer tube  50 . The variable portion  36  connects the inner tube  48  to the outer tube  50 . One end of the inner tube  48  is threadably connected to the variable portion  36  at a position  51 , and another end of the inner tube  48  is connected to the second attachment portion  26 . Also, one end of the outer tube  50  is threadably connected to the variable portion  36  at a position  52 , and another end of the outer tube  50  is connected to the first attachment portion  24 . The linking member  22  has a higher coefficient of thermal expansion than both the inner tube  48  and the outer tube  50 . 
         [0048]    As can be appreciated, axial extension of the variable portion  36  causes the first attachment portion  24  and the second attachment portion  26  to move axially away from each other. Also, axial retraction of the variable portion  36  causes the first attachment portion  24  and the second attachment portion  26  to move axially toward each other. 
         [0049]    In this example, the first attachment portion  24  is directly secured to the outer tube  50  via an interference fit. That is, the first attachment portion  24  includes a radially oversized area relative to the outer tube  50  that is received within the outer tube  50 . The oversized areas cause the outer tube  50  to hold the first attachment portion  24  within the outer tube  50 . The second attachment portion  26  is received within the inner tube  48  and held relative to the inner tube  48  via an interference fit. In other examples, the first attachment portion  24  and the second attachment portion  26  are secured using other techniques. 
         [0050]    In this example, the variable portion  36  is also threadably attached to a base  53 . The base  53  establishes an aperture  54  that receives a portion of the inner tube  48  and the second attachment portion  26 . A collet nut (not shown) may be used to secure the inner tube  48  and the second attachment portion  26  within the aperture  54 . 
         [0051]    The inner tube  48  is also threadably secured to a spacer  58  that helps radially centers the inner tube  48  within the outer tube  50  during extension and retraction of the variable portion  36 . The spacer  58  slides within the outer tube  50  along an inner wall  59  of the outer tube  50 . 
         [0052]    Referring to another example linking member  22   a  of  FIG. 6 , includes a variable portion  36   a  that is heated using a technique other than moving a heated fluid near the variable portion  36   a . In this example, the variable portion  36   a  is heated with a heat tape  60  that is wrapped about areas of the variable portion  36   a . To extend a first attachment portion  24   a  relative to the second attachment portion  26   a , a controller  62  sends a current through the heat tape  60 , which introduces thermal energy to the variable portion  36   a  to extend the variable portion  36   a . Retracting the linking member  22   a  would take place when current to the heat tape  60  is blocked and the variable portion  36   a  is allowed to cool by ambient air or bleed air. 
         [0053]    A person having skill in the art and the benefit of this disclosure may understand still other techniques to heat and cool the variable portions  36  and  36   a  of the disclosed examples. 
         [0054]    Although described as securing components having different coefficients of thermal expansion. The example adjustable linking members  22  and  22   a  may be used to secure components having the same coefficient of thermal expansion. 
         [0055]    The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this disclosure. Thus, the scope of legal protection given to this disclosure can only be determined by studying the following claims.