Patent Abstract:
A guard system for a coupling that connects a first component to a second component in a pressurized machinery system includes a coupling guard moveable between an open position, which allows access to an internal region of the coupling, and a closed position, which forms a seal surrounding the coupling from the first component to the second component. The system also includes a guide for directing movement of the coupling guard.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     Cross Reference 
     This application is a United States national phase application of co-pending international patent application number PCT/US2007/079352, filed Sep. 25, 2007, which claims priority to U.S. Provisional Patent Application No. 60/826,805, filed Sep. 25, 2006, the disclosures of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     The present invention relates to connection members for components of pressure containing machinery and, more particularly, a coupling guard system for protecting and sealing an interior region of a coupling between components of the pressure containing machinery. 
     In existing close-coupled pressure containing machinery, the pressure containing device and structural support are combined into one unit. Historically, access to a coupling and its components has been limited due to generally small access ports in an outer casing of the coupling, which are provided for maintenance access. Combining the pressure sealing and structural support components leads to difficulty creating and maintaining a sealing surface between the co-joined equipment when sealing to contain low mole weight gasses. 
     SUMMARY 
     In one embodiment, the invention provides a guard system for a coupling that connects a first component to a second component in a pressurized machinery system. The guard system includes a coupling guard moveable between an open position, which allows access to an internal region of the coupling, and a closed position, which forms a seal surrounding the coupling from the first component to the second component. The guard system also includes a guide for directing movement of the coupling guard. 
     In another embodiment, the invention provides a guard system including a coupling guard moveable between an open position, which allows access to an internal region of the coupling, and a closed position, which forms a seal surrounding the coupling from the first component to the second component. A guide for directing movement of the coupling guard extends between the first component and the second component wherein the coupling guard is moveably coupled to the guide. An adjuster is coupled to the coupling guard for adjusting a position of the coupling guard relative to the guide. 
     In yet another embodiment, the invention provides a pressure containing coupling guard system for connecting a compressor casing to a drive casing in an industrial compression system. The coupling guard system includes a coupling guard moveable between an open position, which allows access to an internal region between the casings, and a closed position, which forms a seal surrounding the internal region. The coupling guard includes sealing surfaces comprising at least one radial sealing surface at one axial end of the coupling guard and at least one circumferential sealing surface at one axial end of the coupling. The system also includes a guide for directing axial movement of the coupling guard, wherein the guide has a slide bar extending between the compressor casing and the drive casing for aligning the coupling guard to at least one of the casings, and an adjuster for adjusting positioning of the coupling guard on the slide bar. 
     Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a close-coupled pressure containing machinery. 
         FIG. 2  is a perspective view of the machinery shown in  FIG. 1 , including a coupling guard system according to one embodiment of the invention and in a closed position. 
         FIG. 3  is a perspective view of the machinery shown in  FIG. 1 , including the coupling guard system shown in  FIG. 2  in an open position. 
         FIG. 4A  is an end view of a coupling guard that is part of the coupling guard system shown in  FIG. 2 . 
         FIG. 4B  is a sectional view of the coupling guard taken along line  4 B- 4 B of  FIG. 4A . 
         FIG. 5  is a perspective view of a slide adjuster that is part of the coupling guard system shown in  FIG. 2 . 
         FIG. 6  is a perspective view of a slide guide that is part of the coupling guard system shown in  FIG. 2 . 
     
    
    
     Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. 
     For example, terms like “central”, “upper”, “lower”, “front”, “rear”, and the like are only used to simplify the description of the present invention and do not alone indicate or imply that the device or element referred to must have a particular orientation. The elements of the retractable pressure containing coupling guard system referred to in the present invention can be installed and operated in any orientation desired. In addition, terms such as, “first”, “second”, and “third” are used herein for the purpose of description and are not intended to indicate or imply relative importance or significance. 
     DETAILED DESCRIPTION 
       FIG. 1  illustrates a close-coupled pressure containing machinery system of a type that is suitable for use with the present invention. In  FIG. 1  there is specifically shown an industrial compression system  10 , which is used in industry to compress gasses or fluids for industrial purposes. The system  10  might, for example, be used on an oil drilling platform or an oil production platform. The industrial compression system  10  includes two compressors  14  close-coupled to a double-ended electric motor drive  18 . This arrangement allows for a compact design with significant benefits over more traditional base-plate mounted compressor trains. Each compressor  14  is surrounded by a cylindrical compressor casing  22  and the motor  18  is surrounded by a cylindrical motor casing  26 . The compressor casing  22  and the motor casing  26  are separate bodies that are positioned to facilitate installation and removal of components. The compressor casing  22  and the motor casing  26  are connected together with a coupling  30  ( FIG. 3 ), which separates pressure containing components and provides a mechanical support structure for connecting the casings  22 ,  26 . 
     Referring to  FIG. 3 , the coupling  30  includes access ports  34 . The ports  34  provide openings to facilitate removal of bearings, seals, gears, electrical connections and other components within an interior region  38  of the coupling  30  while the electrical drive  18  and the compressor  14  remain connected together. The coupling  30  is attached to the compressor casing  22  and the motor casing  26  with an attachment structure that resists various forces thereon. In the illustrated embodiment, a main case attachment structure  42 , or casing, includes threaded studs and nuts for coupling  30  the coupling to the motor casing  26 , and the like may be used for coupling the coupling  30  to the compressor casing  22 . Other means of mechanical attachment may be employed such as shear rings or other commonly used attachment structures. The attachment structure  42  should be sufficiently sound structurally to prevent separation, vibration, disattachment, torquing or other problems in the integrity of the attachment of the compressor casing  22  to the motor casing  26 . 
     In the illustrated embodiment, a coupling guard system  46  covers the coupling  30  to allow increased maintenance access to the coupling  30  and the associated components while maintaining a high degree of sealed joint integrity. The coupling guard system  46  is a retractable, pressure containing guard system. The coupling guard system  46  separates pressure containing components of the machinery system  10  from structural support components, and maintains a pressure seal over the access ports  34  in the coupling  30 . It is desirable that the pressure containing structure  46  is independent of the main structural mechanical connection  30 ; therefore, a pressure containing sealing surface is not subject to mechanical loads associated with support and operation of the equipment. As an independent structure, the pressure containing sealing surface provides ease of maintenance and sealing integrity. 
       FIG. 2  illustrates the coupling guard system  46  in a closed position to protect the coupling  30 , and  FIG. 3  illustrates the coupling guard system  46  in an open position to allow access to the coupling  30 . In the open position, access to the interior region  38  of the coupling  30  is gained through the ports  34 . In the closed position, the ports  34  are covered by a coupling guard  50 , or cover, in order to seal the coupling  30  and components contained within the coupling  30 . The coupling guard  50  is mounted to the machinery system  10  for axial movement, and may be locked into position to form a sealing surface over the coupling  30 . 
     The coupling guard system  46  includes the coupling guard  50  ( FIGS. 4A and 4B ), two pairs of slide blocks  54  ( FIG. 5 ), or adjusters, and two slide guides  58  ( FIG. 6 ), or bars. The coupling guard  50  is generally cylindrical and includes an exterior surface  62  and an interior surface  66 . In the illustrated embodiment, the coupling guard  50  is constructed as a single ring having no bolted joints. The guard  50  includes two slots  70  defined on the exterior surface  62  with the slots  70  spaced approximately 180° apart. For example, one slot  70  is provided at a nine o&#39;clock position and the other slot  70  is at a three o&#39;clock position to control alignment and axial movement of the guard  50 . Each slot  70  is defined by a pair of radially extending projections  74 , and receives a slide guide  58  for sliding movement thereon. A radially extending flange  78  extends between the first and second slots  70 . Structural ribs, lifting lugs, vents, drains and injection connections in the coupling guard  50  may be varied as appropriate and necessary. Any connecting hardware, pattern of openings, construction of casing and direction that the coupling guard retracts may be varied as appropriate or necessary. 
     At each axial end  82  of the coupling guard  50 , sealing members  86 ,  90  are positioned such that when the coupling guard system  46  is in the closed position, the sealing members  86 ,  90  operate to prevent pressurized gases from escaping from the interior region  38  of the coupling  30 . The sealing members  86 ,  90  provide a high integrity seal when the coupling guard system  46  is in the closed position. Various locations for the sealing members  86 ,  90  may be used as long as seal integrity is maintained. In the illustrated embodiment, the coupling guard  50  includes the sealing members  86 ,  90  or elements to facilitate sealing between the coupling guard system  46 , the coupling  30  and the casings  22 ,  26 . Sealing member  86  is positioned on a radial surface at each axial end  82  of the coupling guard  50 . Sealing members  90  are positioned on the interior surface  66  of the coupling guard  50  at each axial end  82 . In one embodiment, the sealing members  86 ,  90  each include a groove formed in the surface of the coupling guard  50  and an O-ring  94  received and retained in the groove. The diameter on which each groove is placed is minimally different so as to minimize axial forces exerted on the coupling guard  50  from the pressurized contents. In one embodiment, the sealing members  86 ,  90  have similar construction in order to minimize axial forces. 
     As shown in  FIGS. 2 and 3 , one pair of slide blocks  54  is attached to the projections  74  defining each slot  70 . Each slide block  54  ( FIG. 5 ) includes first and second end surfaces  98  and first and second side surfaces  102 . An aperture  106  extends through the first and second end surfaces  98  for slidingly receiving a slide bar  110  extending from the motor casing  26  towards the compressor casing  22 . The slide bar  110  provides directional guidance to the coupling guard system  46 . At least one side surface  102  of the slide block  54  includes a pair of apertures  114  for coupling the block  54  to the coupling guard  50 . In the illustrated embodiment, a roller  118  is positioned between the coupling apertures  114  for facilitating sliding movement of the coupling guard  50  along the slide guides  58 . The roller  118  is directed toward the slot  70  such the respective slide guide  58  is sandwiched between the coupling guard slot  70  and the slide block  54 . The slide blocks  54  are used as a manual slide adjuster to axially move the coupling guard  50  relative to the casings  22 ,  26 . It should be readily apparent to those of skill in the art that other types of friction reducing components, such as low-friction inserts, may be used in the slide blocks  54 . 
     The coupling guard system  46  includes the two slide guides  58  for providing directional guidance and support to the coupling guard  50  in axial movement between the closed position and the open position. Each slide guide  58  extends between the compressor casing  22  and the motor casing  26 , as is coupled thereto. In one embodiment, the slide guides  58  may operate as an assembly tool. In still another embodiment, rollers may be provided in the slide guides  58  for facilitating sliding movement of the coupling guard  50 . Referring to  FIG. 2 , a lock block  122  is positioned between the coupling guard  50  and a motor casing end of the slide guide  58  to prevent axial movement of the coupling guard  50  when in the closed position. It should be readily apparent to those of skill in the art that other known locking mechanisms may be used. Further, fewer or more slide guides  58  may be used. Also, other means for positioning and directing movement of the coupling guard  50 , such as a linear tab engaging a slot or other type of similar positioning member, may be used. 
     In  FIGS. 2 and 3 , only one side of the coupling guard system  46  is shown; therefore, only one pair of slide blocks  54  and one slide guide  58  is shown. The second pair of slide blocks  54  and second slide guide  58  is located on the opposite side of the coupling guard system  46 . That is, the slide blocks  54  and slide guides  58  are positioned approximately 180° degrees apart on each side of the coupling guard  50 . 
     Referring to  FIG. 2 , the retractable pressure containing coupling guard system  46  is shown in a closed position. In the closed position, the sealing members  86 ,  90  engage mating surfaces on the compressor casing  22  and motor casing  26  to form a sealed enclosure around the coupling  30 . A lock block  122  is positioned between the coupling guard  50  and a motor casing end of the slide guide  58  to prevent axial movement of the coupling guard  50 . The lock block  122  provides a positive axial stop, while allowing the coupling guard  50  to float on the sealing surfaces  86 ,  90  as necessary during equipment operation. The lock block  122  is removed or moved to a non-blocking position in order to move the coupling guard system  46  to the open position. 
     To move the coupling guard system  46  to the open position, a user utilizes the slide blocks  54 , or manual slide adjusters, to physically slide the coupling guard  50  along the slide guides  58 . Rollers  118  on the slide blocks  54  facilitate sliding movement of the coupling guard  50 . In a further embodiment, electric, hydraulic or pneumatic mechanisms may also be employed as a means to slide the coupling guard  50  between the closed position and the open position. 
     The coupling guard system  46  enables opening and closing of the coupling guard  50  with a simple, convenient process, and provides for ease of maintenance and sealing integrity. 
     The embodiments described above and illustrated in the figures are presented by way of example only and are not intended as a limitation upon the concepts and principles of the present invention. As such, it will be appreciated by one having ordinary skill in the art that various changes in the elements and their configuration and arrangement are possible without departing from the spirit and scope of the present invention. 
     Since other modifications, changes and substitutions are intended in the foregoing disclosure, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.

Technology Classification (CPC): 5