Patent Publication Number: US-2015068416-A1

Title: Low profile laminate assemblies

Description:
RELATED APPLICATION 
     This application claims priority to U.S. Provisional Application No. 61/876,277, filed Sep. 11, 2013. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     This invention was made with government support under Contract No. N00014-12-D-0372-0001, awarded by the United States Navy. The Government has certain rights in this invention. 
    
    
     BACKGROUND 
     This application relates to an assembly of a plurality of laminate components, wherein a compression element is provided between outer ends of endplates for the assembly. 
     Laminate assemblies are utilized in a number of applications. As one example, a plurality of fuel cells may be mounted on a vehicle and stacked atop each other as a laminate assembly. Typically, endplates are placed at outer ends of the assembly. 
     It is important to maintain compression across the assembly and, thus, it is known to have bolts or other securement members mount Belleville washers at a location outwardly of one of the endplates. 
     The overall height of the assembly is, thus, increased, in that the Belleville washers and associated mount structures are positioned beyond an outer end of the endplates. 
     SUMMARY 
     An assembly has a plurality of laminate components aligned atop each other. A first endplate is at one end of the assembly of components and a second endplate is at an opposed end. The first and second endplates have outer surfaces facing away from the components. A spring force applies a compressive force to bias the first and second endplates together and, in turn, apply a force across the laminate components. The spring force is provided by a spring mounted between the outer surfaces of the first and second endplates. 
     These and other features may be best understood from the following drawings and specification. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a first embodiment. 
         FIG. 2  shows a second embodiment. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows an assembly  20  including a plurality of laminate components  22 ,  24 ,  26 ,  28 ,  30 ,  32 ,  33 ,  34 , etc. 
     Endplates  36  and  38  are mounted at ends of the laminate assembly. Endplate  36  has an outer surface  37  and endplate  38  has an outer surface  39 . Endplate  36  has an inner surface  41  facing the laminate components  22 - 34  and endplate  38  has an inner surface  43  also facing the components. 
     The laminate components  22 - 34  are generally planar and have a large cross-sectional face P. The components  22 - 34  are stacked with their planar surfaces P atop and in contact with each other. An axial distance X can be defined perpendicular to the planar surface. 
     In applications, the laminate components may be fuel cells. One application for the assembly  20  would be on unmanned vehicles, such as a space, or underwater, vehicle. Alternatively, they could be electrolyzers, such as utilized to provide oxygen. Further, they could be a plurality of heat exchanger cores. Other generally planar components can also benefit from these teachings. 
     It is important to maintain compression across the assembly  20  and, thus, Belleville washers  48  apply a tension force drawing the endplates  36  and  38  together to maintain a compression bias across the stack of components  22 - 34 . 
     The Belleville washers  48  are mounted within a barrel  46 . As shown, the Belleville washers are intermediate, or between, the surfaces  41  and  43 . More generally, they are axially intermediate, or between, the surfaces  37  and  39 . 
     The barrel  46  has a flange  40  extending over a limited circumferential range and bolted at  42  to the endplate  36 . Bolt  42  extends into a hole  44 . Of course, other ways to secure the barrel  46  to endplate  36  may be used. 
     It should be understood that a plurality of the barrels  46  may be spaced about the assembly  20 . A long bolt  54  has a head  50  abutting a washer  51  at one end of the Belleville washers  48  and applying a compressive force on the Belleville washers  48  against an inner lip  47  of the barrel  46 . A threaded end  55  of the long fastener  54  is threaded into a blind hole  52  in the opposed endplate  38 . 
     When the assembly  20  is assembled, the bolts  50  may be tightened through the Belleville washers  48  and into the threads in the blind hole  52 . In this manner, the compressive force is maintained on the assembled components  22 - 34 . 
     As known, the Belleville washers  48  maintain a compressive force which is able to compensate for creep or other adjustment in the size of the components  22 - 34  over time. 
     By providing the Belleville washers  48  between the surfaces  41  and  43 , the overall height of the assembly  20  is reduced compared to the prior art. 
     As shown in  FIG. 2  in another embodiment  120 , the long fasteners  154  extend through a hole  152  in the end plate  38  and receive a washer  156  and nut  158 . This embodiment may require a compressive jig to apply compression as the nuts  158  are tightened on the long fasteners  154 . 
     The laminate components  22 - 34  are generally planar and have a large cross-sectional face P. The components  22 - 34  are stacked with their planar surfaces P atop and in contact with each other. An axial distance X can be defined perpendicular to the planar surface. 
     Endplates  36  and  138  are mounted at ends of the laminate assembly. Endplate  36  has an outer surface  37  and endplate  138  has an outer surface  139 . Endplate  36  has an inner surface  41  facing the laminate components  22 - 34  and endplate  138  has an inner surface  143  also facing the components. 
     In applications, the laminate components may again be fuel cells. One application for the assembly  120  would be on unmanned vehicles, such as a space, or underwater, vehicle. Alternatively, they could also be electrolyzers, such as utilized to provide oxygen, or a plurality of heat exchanger cores. Other generally planar component can also benefit from these teachings. 
     It is again important to maintain compression across the assembly  120  and, thus, Belleville washers  48  apply a tension force drawing the endplates  36  and  138  together to maintain a compression bias across the stack of components  22 - 34 . 
     The Belleville washers  48  are mounted within a barrel  46 , are intermediate, or between, the surfaces  41  and  143 . More generally, they are axially intermediate, or between, the surfaces  37  and  139 . 
     While Belleville washers  48  are disclosed, other types of springs and biasing devices may be utilized to provide a spring force. Examples may be wave washers or other compression springs. Helical springs or bellows springs could also be used. This list is not intended to be exhaustive. 
     Although an embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this disclosure. For that reason, the following claims should be studied to determine the true scope and content of this disclosure.