Braid construction to match coefficients of thermal expansion for composite transmission housings

Abstract

A transmission assembly includes a composite transmission component with a tailored coefficient of thermal expansion (CTE). The composite transmission component is fabricated from graphite axial fibers and S-glass bias fibers that are oriented at a bias angle to the graphite axial fibers. The composite transmission component is located adjacent to a second composite transmission component and a metal transmission component. A first CTE of the composite transmission component is tailored to a CTE of the second composite component. A second CTE of the composite transmission component is tailored to a metal CTE of the metal transmission component. The first and second CTE are tailored by utilizing graphite axial fibers and S-glass bias fibers, or two other different types of fibers, and by controlling the bias angle. The tailored first and second CTE minimize thermal strain and maintain a tight fit between the components.

1 . A composite article comprising: 
 a plurality of first fibers having a first orientation and controlling a first coefficient of thermal expansion (CTE) in a first direction;    a plurality of second fibers adjacent to said plurality of first fibers, said plurality of second fibers having a second orientation and controlling a second CTE in a second direction which is different than said first direction, said plurality of first fibers being different than said plurality of second fibers.    
     
     
         2 . The article as recited in  claim 1 , wherein said first direction is in a first plane and said second direction is in a second plane that is different from said first plane.  
     
     
         3 . The article as recited in  claim 1 , wherein said first CTE is different than said second CTE.  
     
     
         4 . The article as recited in  claim 1 , wherein said plurality of second fibers are interwoven with said plurality of first fibers.  
     
     
         5 . The article as recited in  claim 1 , wherein said plurality of first fibers comprise glass fibers.  
     
     
         6 . The article as recited in  claim 1 , wherein said plurality of first fibers comprise Kevlar™ fibers.  
     
     
         7 . The article as recited in  claim 1 , wherein said plurality of second fibers comprise graphite fibers.  
     
     
         8 . The article as recited in  claim 1 , wherein said plurality of first fibers have a volumetric ratio of about 2:1 to said plurality of second fibers.  
     
     
         9 . The article as recited in  claim 1 , wherein said first orientation comprises an angular bias between essentially 0° and +/−90° relative to an axis and said second orientation is generally parallel to said axis.  
     
     
         10 . The article as recited in  claim 9 , wherein said angular bias is between +/−55° and +/−70°.  
     
     
         11 . A transmission assembly comprising: 
 a first transmission component having a first CTE in an axial direction;    a second transmission component adjacent to said first transmission component, said second transmission component having a second CTE in said axial direction and a third CTE in a non-axial direction, said third CTE being different than said second CTE; and    a third transmission component adjacent to said second transmission component, said third transmission component having a fourth CTE in said non-axial direction.    
     
     
         12 . The assembly as recited in  claim 11 , wherein said second CTE is generally equal to said first CTE.  
     
     
         13 . The assembly as recited in  claim 11 , wherein said third CTE is greater than said fourth CTE.  
     
     
         14 . The assembly as recited in  claim 11 , wherein said third CTE is less than said fourth CTE.  
     
     
         15 . The assembly as recited in  claim 11 , wherein said third transmission component is located radially inward from said second transmission component.  
     
     
         16 . The assembly as recited in  claim 11 , wherein said third transmission component is located radially outward from said second transmission component.  
     
     
         17 . The assembly as recited in  claim 11 , wherein said non-axial direction is a hoop direction.  
     
     
         18 . The assembly as recited in  claim 11 , wherein said first transmission component is a graphite composite case, said second transmission component is a composite support, and said third transmission component is a metal bearing component.  
     
     
         19 . A method of tailoring a coefficient of thermal expansion (CTE) of a composite comprising: 
 (a) orienting a plurality of first and second fibers in a first and second orientation, respectively, to form a composite;    (b) controlling a first CTE of the composite with the plurality of first fibers; and    (c) controlling a second CTE of the composite with the plurality of second fibers.    
     
     
         20 . The method as recited in  claim 19 , wherein the step (a) includes providing glass fibers and graphite fibers as the plurality of first and second fibers, respectively.  
     
     
         21 . The method as recited in  claim 19 , wherein the step (a) includes orienting the plurality of first fibers with an angular bias to an axis and orienting the plurality second fibers parallel to the axis.  
     
     
         22 . The method as recited in  claim 19 , including the steps of controlling the first CTE to be equal to or greater than a CTE of a metal component adjacent to the composite and controlling the second CTE to be generally equal to a composite component adjacent to the composite.  
     
     
         23 . The method as recited in  claim 19 , including the steps of controlling the first CTE to be equal to or less than a CTE of a metal component adjacent to the composite and controlling the second CTE to be generally equal to a composite component adjacent to the composite.