Abstract:
A high pressure bellows assembly is disclosed herein. The high pressure bellows assembly includes a first bellows being reversibly expandable. The high pressure bellows assembly also includes a second bellows being reversibly expandable. The high pressure bellows assembly also includes a chamber including a first portion encircling the first bellows, a second portion including an interior of the second bellows, and a third portion placing the first and second portion in fluid communication.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/721,209 for a HIGH PRESSURE BELLOWS ASSEMBLY, filed on Nov. 1, 2012, which is hereby incorporated by reference in its entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The invention relates to an apparatus for actuating a deep-sea drill. 
         [0004]    2. Description of Related Prior Art 
         [0005]    U.S. Pat. No. 5,662,335 discloses a pressure balanced bellows seal. The bellows seal includes a seal bellows assembly which is operatively and sealingly attached to the valve stem, a counterbellows assembly which is substantially concentric with the seal bellows assembly, a midplate which operatively joins the seal bellows assembly and the counterbellows assembly in an end-to-end arrangement and an inert fluid within the cavity formed by the seal bellows assembly and the counterbellows assembly and which is moveable therebetween to compensate for volumetric changes resulting from the axial movement of the valve stem. The inert fluid balances the pressure of the process fluid and distributes it substantially uniformly against the seal bellows assembly and the counterbellows assembly thus substantially eliminating any pressure stresses within the bellows assemblies. 
         [0006]    U.S. Pub. No. 2013/0032226 discloses a GAS LIFT VALVE HAVING EDGE-WELDED BELLOWS AND CAPTIVE SLIDING SEAL. A gas lift apparatus has a gas lift valve that disposes in a mandrel. A housing of the valve has a chamber, and a seat disposes between the inlet and outlet. A piston movably disposed in the housing has one end exposed to the chamber. A distal end can selectively seal with the seat to close the valve. A first edge-welded bellows disposed on the piston separates the inlet and chamber pressures and can fully compress to a stacked height when the distal end of the piston seals with the seat. A dynamic seal can be achieved at closing by using a captive sliding seal between the piston&#39;s distal end and the seat. A second edge-welded bellows can also be disposed on the piston, and the two bellows can operate in tandem. Oil filing the interiors and the passage can move from one bellows to the other to transfer the pressure differential between the inlet and the chamber pressures. The second bellows fully compresses to a stacked height and stops opening of the valve. 
       SUMMARY OF THE INVENTION 
       [0007]    In summary, the invention is a high pressure bellows assembly. The high pressure bellows assembly includes a first bellows being reversibly expandable. The high pressure bellows assembly also includes a second bellows being reversibly expandable. The high pressure bellows assembly also includes a chamber including a first portion encircling the first bellows, a second portion including an interior of the second bellows, and a third portion placing the first and second portion in fluid communication. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The following detailed description is best considered in connection with the accompanying drawings: 
           [0009]      FIG. 1  is a cross-section of an exemplary embodiment of the invention; 
           [0010]      FIG. 2  is a cross-section of a second exemplary embodiment of the invention; and 
           [0011]      FIG. 3  is a magnified portion of  FIG. 2 . 
       
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0012]    A plurality of different embodiments of the invention is shown in the Figures of the application. Similar features are shown in the various embodiments of the invention. Similar features have been numbered with a common reference numeral and have been differentiated by an alphabetic suffix. Also, to enhance consistency, the structures in any particular drawing share the same alphabetic suffix even if a particular feature is shown in less than all embodiments. Similar features are structured similarly, operate similarly, and/or have the same function unless otherwise indicated by the drawings or this specification. Furthermore, particular features of one embodiment can replace corresponding features in another embodiment or can supplement other embodiments unless otherwise indicated by the drawings or this specification. 
         [0013]    The invention, as demonstrated by the exemplary embodiments described below, provides an improved actuator for operating environments in which a bellows is applied to move another structure and, further, in which the bellows may be subjected to relatively high pressure. 
         [0014]      FIG. 1  shows a first exemplary high pressure bellows assembly  10 . The exemplary assembly  10  includes first and second housings  12 ,  14 . The exemplary first and second housings  12 ,  14  can be cylindrical. The exemplary assembly  10  can also include a manifold  16  interconnecting the first and second housings  12 ,  14 . The manifold  16  can be welded to both of the first and second housings  12 ,  14 . Other methods and arrangements for interconnecting the first and second housings  12 ,  14  and the manifold  16 , both releasibly and permanently, can be applied in embodiments of the invention. 
         [0015]    The assembly  10  can also include first and second end caps  18 ,  20 . The end cap  18  can engage an end of the housing  12  opposite to the manifold  16 . The housing  12 , the end cap  18 , and the manifold  16  can cooperate with one another to define at least part of a first chamber  22 . The end cap  20  can engage an end of the housing  14  opposite to the manifold  16 . The housing  14 , the end cap  20 , and the manifold  16  can cooperate with one another to define at least part of a second chamber  24 . The end caps  18 ,  20  can be releasibly or permanently engaged with the respective housing  12 ,  14 . 
         [0016]    The assembly  10  can also include first and second bellows  26 ,  28 . The first bellows  26  can be positioned within the first housing  12  and extend between first and second ends  30 ,  32  along a central axis  34  of the assembly  10 . The first end  30  can be fixedly engaged with the end cap  18  and be sealed with respect to the end cap  18 . A spout  36  can be integrally formed with the end cap  18  and project into the first end  30  of the first bellows  26 . A first valve member  38  (or valve closing member) can be sealingly engaged with the second end  32 . The bellows  26  can expand as fluid is received internally. 
         [0017]    The second bellows  28  can be positioned within the second housing  14  and extend between first and second ends  40 ,  42  along the central axis  34  of the assembly  10 . The first end  40  can be fixedly engaged with the manifold  16  and be sealed with respect to the manifold  16 . A spout  44  can be integrally formed with the manifold  16  and project into the first end  40  of the second bellows  28 . A second valve member  46  (or valve closing member) can be sealingly engaged with the second end  42 . The bellows  28  can expand as fluid is received internally. 
         [0018]    The manifold  16  can include a port  48 . Incompressible fluid can be directed into the chamber  22  through the port  48  and the port  48  can then be sealed. The exemplary chamber  22  can include a first portion defined by the housing  12  and encircling the first bellows  26 . The exemplary chamber  22  can also include a second portion defined by a passageway  50  extending through the manifold  16 . The exemplary chamber  22  can also include a third portion being the interior of the second bellows  28 . As will be set forth more fully below, the first, second and third portions of the chamber  22  can be selectively closed from one another. 
         [0019]    A passageway  52  can extend through the end cap  18 . The passageway  52  can extend through the spout  36  to fluidly communicate with the interior of the first bellows  26 . A fluid delivery system, referenced schematically at  54 , can be used to selectively direct pressurized fluid to the passageway  52  and thus to the interior of the first bellows  26 . Fluid can be selectively directed into the interior of the first bellows  26  and selectively allowed to exit the interior of the first bellows  26 . 
         [0020]    A passageway  56  can extend through the end cap  20 . The passageway  56  can fluidly communicate with the chamber  24 . A fluid delivery system, referenced schematically at  58 , can be used to selectively direct pressurized fluid to the passageway  56  and thus to the chamber  24 . It is noted that in some embodiments of the invention a single fluid delivery system can be applied; the fluid delivery systems  54  and  58  can be sub-systems of single, comprehensive system controlled by a single controller. Fluid can be selectively directed into the chamber  24  and selectively allowed to exit the chamber  24 . 
         [0021]    The second valve member  46  can be integrally-formed with or engaged to a rod  60 . The rod  60  can project through a passageway  62  in the end cap  20 . The rod  60  can be engaged with a deep sea drill bit (not shown). Extension of the rod  60  out of the assembly  10  (to be described in detail below) urges the drill bit forward, such as to engage the sea bed. Retraction of the rod  60  into the assembly  10  draws the drill bit back, such as out of engagement with the sea bed. 
         [0022]    In operation, the rod  60  can be extended by directing fluid through the passageway  52  and spout  36 , into the first bellows  26 . The first bellows  26  expands in response and the valve member  38  is urged toward the manifold  16  along the axis  34 . As a result, fluid in the chamber  22  is urged through the passageway  50  and into the interior of the second bellows  28 . The second bellows  28  expands in response and the valve member  46  and rod  60  are urged toward the end cap  20  along the axis  34 . 
         [0023]    When it is desired to retract the rod  60 , fluid can be directed through the passageway  56 , into the second chamber  24 . The second bellows  28  collapses in response and the valve member  46  is urged toward the manifold  16  along the axis  34 . As a result, fluid in the third portion of the chamber  22  (the interior of the second bellows  28 ) is urged through the passageway  50  and into the interior of the housing  12 . The first bellows  26  is collapsed in response and the valve member  38  is urged toward the end cap  18  along the axis  34 . 
         [0024]    The assembly includes first and second valves  64  and  66  to protect the bellows  26  and  28  from damage that can arise when large pressure differentials arise between the outside and inside of either of the bellows  26 ,  28 . The first valve  64  can include the valve member  38  and a valve seat  68 . The valve seat  68  can be mounted on the manifold  16  and cooperate with the valve member  38  to selectively close the passageway  50 . The valve seat  68  can be fixed to the manifold  16  with a collar  70 . In operation, the valve member  38  can be urged along the axis  34  toward the manifold  16  until the valve member  38  contacts and seats on the valve seat  68 , closing the passageway  50 . In the exemplary embodiment, the valve member  38  is a single, integrally-formed structure that serves two purposes: closing an end of the bellows  26  and acting as the moveable portion of a fluid valve. However, in other embodiments, two separate structures interconnected together could be applied. 
         [0025]    The second valve  66  can include the valve member  46  and a valve seat  72 . The valve seat  72  can be mounted on the manifold  16  and cooperate with the valve member  46  to selectively close the passageway  50 . The valve seat  72  can be fixed to the manifold  16  with a collar  74 . In operation, the valve member  46  can be urged along the axis  34  toward the manifold  16  until the valve member  46  contacts and seats on the valve seat  72 , closing the passageway  50 . 
         [0026]    It can be desirable to minimize the pressure differential across the bellows  26 ,  28 , the difference in pressure between an interior of either bellows and an exterior of that bellows. It is believed that relatively high pressure differentials compromise the useful life of the bellows. In the exemplary embodiment of the invention, a pressure differential can arise if one of the fluid delivery systems fails. Relatively small pressure differentials allow for movement of the rod. However, the pressure differential can spike to undesirable levels if one of the fluid delivery systems fails or if containment of the fluid in either chamber is compromised. 
         [0027]    High pressure differentials can lead to full compression of the bellows. The bellows  26 ,  28  can be formed or fabricated from metal. For a fabricated bellows having welded edges, full compression of the bellows  28  can press weld beads against each other that might be radially aligned along the length of the bellows  28 . For example, the manufacture of the bellows  28  might involve the formation of weld bead at the crest or trough of each bellow. If the bellows were fully compressed, these weld beads would be pressed against each other. It is believed that such an event would shorten the useful life of the bellows. However, in some operating environments at least, full compression may not be desirable for a formed bellows either. 
         [0028]    In one example, fluid can be directed through the passageway  56 , to the second chamber  24 . The second bellows  28  can be compressed in response. If the control over the fluid pressure in the first chamber  22  is compromised, the second bellows  28  might be fully compressed or worse without the presence of the valve  66 . First, without the valve  66 , the exterior surface of the second bellows  28  could be pressed radially inward since fluid could be urged into the first chamber  22  if control over the pressure in the first chamber  22  is not maintained. However, the exemplary embodiment provides further protection of the second bellows  28  by arranging the valve  66  to close even before the second bellows  28  is fully compressed. In other words, the valve member  46  can seat on the valve seat  72  before the second bellows  28  is fully compressed. Immediately prior to the closing of the valve  66 , as the second bellows  28  is being compressed, the pressure differential between the interior of the second bellows  28  and the exterior of the second bellows  28  is relatively small. The valve  66  is arranged to close during these conditions to maintain the relatively small pressure differential. The fluid inside the second bellows  28  is incompressible and cannot escape to the first chamber  22 , so the wall of the bellows  28  is protected from being fully compressed along the axis  34  or radially collapsed. 
         [0029]    The valve  64  can similarly protect the first bellows  26 . Fluid can be directed through the passageway  52 , to the first chamber  22 . The first bellows  26  can be expanded in response. If the control over the fluid pressure in the second chamber  24  is compromised, the first bellows  26  might be fully expanded without the presence of the valve  64 . The exemplary embodiment arranges the valve  64  to close before the first bellows  26  is fully expanded. In other words, the valve member  38  can seat on the valve seat  68  before the first bellows  26  is fully expanded. Immediately prior to the closing of the valve  64 , as the first bellows  26  is being expanded, the pressure differential between the interior of the first bellows  26  and the exterior of the first bellows  26  is relatively small. The valve  64  is arranged to close during these conditions to maintain the relatively small pressure differential. The fluid outside the first bellows  26  is incompressible and cannot escape to the second chamber  24 , so the wall of the bellows  26  is protected from being fully expanded along the axis  34 . 
         [0030]    A sealing element  76  is shown encircling the rod  60 . The sealing element  76  can to seal the fluid between the rod  60  and the end cap  20 . There are different choices of sealing element in the market that can be selected. What it is shown in the drawing of the exemplary embodiment it is not necessary for practicing the invention. 
         [0031]      FIG. 2  is a cross-section of a second exemplary embodiment of the invention.  FIG. 2  shows an exemplary high pressure bellows assembly  10   a.  The exemplary assembly  10   a  includes first and second housings  12   a,    14   a.  The exemplary first and second housings  12   a,    14   a  can be cylindrical. The exemplary assembly  10   a  can also include a manifold  16   a  interconnecting the first and second housings  12   a,    14   a.  The manifold  16   a  can be welded to both of the first and second housings  12   a,    14   a.  Other methods and arrangements for interconnecting the first and second housings  12   a,    14   a  and the manifold  16   a,  both releasibly and permanently, can be applied in embodiments of the invention. 
         [0032]    The assembly  10   a  can also include first and second end caps  18   a,    20   a . The end cap  18   a  can engage an end of the housing  12   a  opposite to the manifold  16   a.  The housing  12   a,  the end cap  18   a,  and the manifold  16   a  can cooperate with one another to define at least part of a first chamber  22   a.  The end cap  20   a  can engage an end of the housing  14   a  opposite to the manifold  16   a.  The housing  14   a,  the end cap  20   a,  and the manifold  16   a  can cooperate with one another to define at least part of a second chamber  24   a.  The end caps  18   a,    20   a  can be releasibly or permanently engaged with the respective housing  12   a,    14   a.    
         [0033]    The assembly  10   a  can also include first and second bellows  26   a,    28   a.  The first bellows  26   a  can be positioned within the first housing  12   a  and extend between first and second ends  30   a,    32   a  along a central axis  34   a  of the assembly  10   a.  The first end  30   a  can be fixedly engaged with the end cap  18   a  and be sealed with respect to the end cap  18   a.  A spout  36   a  can be integrally formed with the end cap  18   a  and project into the first end  30   a  of the first bellows  26   a.  A first valve member  38   a  (or valve closing member) can be sealingly engaged with the second end  32   a.  The bellows  26   a  can expand as fluid is received internally. 
         [0034]    The second bellows  28   a  can be positioned within the second housing  14   a  and extend between first and second ends  40   a,    42   a  along the central axis  34   a  of the assembly  10   a.  The first end  40   a  can be fixedly engaged with the manifold  16   a  and be sealed with respect to the manifold  16   a.  A second valve member  46   a  (or valve closing member) can be sealingly engaged with the second end  42   a.  The bellows  28   a  can expand as fluid is received internally. 
         [0035]    The manifold  16   a  can include a port  48   a.  Incompressible fluid can be directed into the chamber  22   a  through the port  48   a  and the port  48   a  can then be sealed. The exemplary chamber  22   a  can include a first portion defined by the housing  12   a  and encircling the first bellows  26   a.  The exemplary chamber  22   a  can also include a second portion defined by a passageway  50   a  extending through the manifold  16   a.  The exemplary chamber  22   a  can also include a third portion being the interior of the second bellows  28   a.  As will be set forth more fully below, the first, second and third portions of the chamber  22   a  can be selectively closed from one another. 
         [0036]    A passageway  52   a  can extend through the end cap  18   a.  The passageway  52   a  can extend through the spout  36   a  to fluidly communicate with the interior of the first bellows  26   a.  A fluid delivery system, such as one referenced schematically at  54  in  FIG. 1 , can be used to selectively direct pressurized fluid to the passageway  52   a  and thus to the interior of the first bellows  26   a.  Fluid can be selectively directed into the interior of the first bellows  26   a  and selectively allowed to exit the interior of the first bellows  26   a.    
         [0037]    A passageway  56   a  can extend through the housing  14   a.  The passageway  56   a  can fluidly communicate with the chamber  24   a.  A fluid delivery system, such as one referenced schematically at  58  in  FIG. 1 , can be used to selectively direct pressurized fluid to the passageway  56   a  and thus to the chamber  24   a.  It is noted that in some embodiments of the invention a single fluid delivery system can be applied; the fluid delivery systems can be sub-systems of single, comprehensive system controlled by a single controller. Fluid can be selectively directed into the chamber  24   a  and selectively allowed to exit the chamber  24   a.    
         [0038]    The second valve member  46   a  can be integrally-formed with or engaged with a rod  60   a.  The rod  60   a  can project through a passageway  50   a  in the end manifold  16   a.  The rod  60   a  can assist in keeping motion of the valve member  46   a  along the axis  34   a.    
         [0039]    The assembly includes first and second valves  64   a  and  66   a  to protect the bellows  26   a  and  28   a  from damage that can arise when large pressure differentials arise between the outside and inside of either of the bellows  26   a,    28   a.  The first valve  64   a  can include the valve member  38   a  and a radial seal  78   a.  The radial seal  78   a  can be mounted on a seal holder  80   a  fixed to the valve member  38   a.  The manifold  16   a  also cooperates to selectively close the passageway  50   a.  In operation, the valve member  38   a  can be urged along the axis  34   a  toward the manifold  16   a  until the seal holder  80   a  contacts is positively stopped by a shoulder  82   a  defined in the passageway  50   a.  When that occurs, the radial seal  78   a  is sealing engaged with the passageway  50   a  and the passageway  50   a  is thus closed. 
         [0040]    The second valve  66   a  can include the valve member  46   a  and a radial seal  84   a.  The radial seal  84   a  can be mounted on a seal holder  86   a  fixed to the valve member  46   a.  The manifold  16   a  also cooperates with the second valve member  66   a  to selectively close the passageway  50   a.  In operation, the valve member  46   a  can be urged along the axis  34   a  toward the manifold  16   a  until the seal holder  86   a  contacts is positively stopped by a shoulder  88   a  defined in the passageway  50   a.  When that occurs, the radial seal  78   a  is sealing engaged with the passageway  50   a  and the passageway  50   a  is thus closed. 
         [0041]    It can be desirable to minimize the pressure differential across the bellows  26   a,    28   a,  the difference in pressure between an interior of either bellows and an exterior of that bellows. It is believed that relatively high pressure differentials compromise the useful life of the bellows. In the exemplary embodiment of the invention, a pressure differential can arise if one of the fluid delivery systems fails. Relatively small pressure differentials allow for movement of the rod. However, the pressure differential can spike to undesirable levels if one of the fluid delivery systems fails or if containment of the fluid in either chamber is compromised. 
         [0042]    High pressure differentials can lead to full compression of the bellows. The bellows  26   a,    28   a  can be formed or fabricated from metal. For a fabricated bellows having welded edges, full compression of the bellows  28   a  can press weld beads against each other that might be radially aligned along the length of the bellows  28   a.  For example, the manufacture of the bellows  28   a  might involve the formation of weld bead at the crest or trough of each bellow. If the bellows were fully compressed, these weld beads would be pressed against each other. It is believed that such an event would shorten the useful life of the bellows. However, in some operating environments at least, full compression may not be desirable for a formed bellows either. 
         [0043]    In one example, fluid can be directed through the passageway  56   a,  to the second chamber  24   a.  The second bellows  28   a  can be compressed in response. If the control over the fluid pressure in the first chamber  22   a  is compromised, the second bellows  28   a  might be fully compressed or worse without the presence of the valve  66   a . First, without the valve  66   a,  the exterior surface of the second bellows  28   a  could be pressed radially inward since fluid could be urged into the first chamber  22   a  if control over the pressure in the first chamber  22   a  is not maintained. However, the exemplary embodiment provides further protection of the second bellows  28   a  by arranging the valve  66   a  to close even before the second bellows  28   a  is fully compressed. In other words, the valve member  46   a  can be positively stopped from moving before the second bellows  28   a  is fully compressed. Immediately prior to the closing of the valve  66   a,  as the second bellows  28   a  is being compressed, the pressure differential between the interior of the second bellows  28   a  and the exterior of the second bellows  28   a  is relatively small. The valve  66   a  is arranged to close during these conditions to maintain the relatively small pressure differential. The fluid inside the second bellows  28   a  is incompressible and cannot escape to the first chamber  22   a,  so the wall of the bellows  28   a  is protected from being fully compressed along the axis  34   a  or radially collapsed. 
         [0044]    The valve  64   a  can similarly protect the first bellows  26   a.  Fluid can be directed through the passageway  52   a,  to the first chamber  22   a.  The first bellows  26   a  can be expanded in response. If the control over the fluid pressure in the second chamber  24   a  is compromised, the first bellows  26   a  might be fully expanded without the presence of the valve  64   a.  The exemplary embodiment arranges the valve  64   a  to close and the valve member  38   a  is positively stopped before the first bellows  26   a  is fully expanded. In other words, the valve member  38   a  can abut the shoulder  82   a  before the first bellows  26   a  is fully expanded. Immediately prior to the closing of the valve  64   a,  as the first bellows  26   a  is being expanded, the pressure differential between the interior of the first bellows  26   a  and the exterior of the first bellows  26   a  is relatively small. The valve  64   a  is arranged to close during these conditions to maintain the relatively small pressure differential. The fluid outside the first bellows  26   a  is incompressible and cannot escape to the second chamber  24   a,  so the wall of the bellows  26   a  is protected from being fully expanded along the axis  34   a.    
         [0045]    Another feature of the second embodiment is a secondary pressure absorption arrangement.  FIG. 3  is a magnified portion of  FIG. 2 . The valve member  38   a  defines annular groove extending about the axis  34   a.  A Belleville washer  90   a  is disposed in the groove. When the valve member  38   a  moves as the first bellows  26   a  is expanded, a ring-like distal end  92   a  of the valve member  38   a  (which encircles the washer  90   a ) is received in a groove  94   a  defined by the manifold  16   a.  At some point during movement of the valve member  38   a  during expansion of the bellows  26   a,  the washer  90   a  contacts an end face  96   a  of the manifold. Expansion of the bellows  26   a  beyond this point causes elastic deformation of the washer  90   a,  as the washer  90   a  is compressed with decreasing distance between the end face  96   a  and the bottom of the annular groove of the valve member  38   a.    
         [0046]    While the invention has been described with reference to an exemplary embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. Further, the “invention” as that term is used in this document is what is claimed in the claims of this document. The right to claim elements and/or sub-combinations that are disclosed herein as other inventions in other patent documents is hereby unconditionally reserved.