Abstract:
A service valve assembly, for use in a split air conditioning/heat pump system, with a single valve block having a plurality of passages, a first valve and a second valve. The assembly includes a first cavity within the block with a first valve holding passage, for conducting gaseous refrigerant inside the valve block. The first valve includes a first through passage radially extending both through the first valve as well as from an outer surface of a first side of the block to an outer surface of a side opposite the first side. A first charging passage extends from the valve block outer surface to the first through passage. The valve block also includes a second cavity, including a second valve holding passage, for conducting liquid refrigerant within the block. The second valve includes a second through passage extending both through the second valve as well as from the outer surface of the valve block first side to the outer surface of the opposite side. A second charging passage extends from the valve block outer surface to the second through passage.

Description:
CROSS-REFERENCE TO RELATED CASES  
       [0001]    The present application claims the benefit of the filing date of U.S. Provisional Application Serial No. 60/453,658; filed Mar. 10, 2003, the disclosure of which is expressly incorporated herein by reference. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates to a service valve assembly, for use in a split air conditioning/heat pump system, having a single valve block with a plurality of passages, a first valve and a second valve, for connecting an outdoor unit with an indoor unit.  
         BACKGROUND OF THE INVENTION  
         [0003]    A condensing unit is a key component of a split residential air-conditioning and heat pump system. The condensing unit is primarily comprised of a compressor, an outdoor coil, an outdoor fan, and line connections. As is well known in the art, during installation of the system, the condensing unit, or outdoor unit, is connected to two lines (high pressure and low pressures sides) that convey refrigerant to and from an indoor unit, primarily comprised of an indoor coil, an indoor fan and an expansion device. These two connections on the condensing unit are made at liquid (high side) and suction (low side) service valves. Service valves provide for shutoffs of connections between the outdoor and indoor units and contain ports for charging and measuring system pressures.  
           [0004]    The service valves are initially shut off in order to retain original factory or recently charged refrigerant in an outdoor unit prior to hookup with an indoor unit. This enables the mobility of outdoor units without the loss of refrigerant during the move. Another function of service valves is to provide a shut-off for the possibility of a “pump-down”. During the “pump-down” process, the liquid service valve is closed and the compressor is turned on so that all of the refrigerant is pulled into and stored in the condensing unit. Thereafter, the indoor coil, expansion device, unit components, such as the fan and lines can be accessed without removing or losing the refrigerant from the system. Another function of the service valves is to provide a service port via which an out-of-system connection (such as a hose) can be made and used to evacuate refrigerant, charge (add) refrigerant, or monitor system pressure for diagnostic purposes.  
           [0005]    When the several components (indoor and outdoor units, etc.) of the system are operatively connected, the lines between the indoor and outdoor coils are initially evacuated of air through charge ports located on both service valves. Thereafter, the service valves are opened, thus allowing pre-charged refrigerant to flow from the charged condensing unit throughout the entire system.  
           [0006]    Prior art structures have utilized two separate valve bodies which house the liquid and suction service valves. These valve bodies are typically aligned with the connecting conduit between the indoor and outdoor units. An example of separate valve bodies for indoor and outdoor units is shown in U.S. Pat. No. 6,158,229 to Aizawa. The process of manufacturing two separate valve bodies to house the liquid and suction valves is expensive. The assembly time needed to mount both bodies onto the condensing unit is lengthy. The complexity is also increased due to the two separate valve bodies. Further, since two separate connections are made, the number of components is increased which increases the number of leak points.  
           [0007]    A typical style of a liquid side service valve is a front-seating valve that exhibits an off-set or stepped “Z” flow path which is not conducive to low pressure drop. This pressure drop can be decreased through methods that add cost to the valve and system. The front seat valve also requires multiple rotations of its valve stem in order to be opened and closed. A typical suction side service valve is a ball-style valve that exhibits a large straight flow path. However, the cost of this style of valve is substantially higher than that of the typical front seat valve. Due to the high cost, many manufacturers opt for the lower cost front seat valve and compensate for the added pressure drop and associated efficiency losses by designing changes in other areas of the system. Ball valves provide a “soft-seal” retention of the refrigerant, rather than the metal-to-metal seal found in front seat valves. The “soft-seal” is provided by the nylon style of seal within the valve. While nylon seals provide good resistance to refrigerant permeation, they will tend to soften from heat and “creep”, thereby causing leaks.  
           [0008]    Another obstacle with ball and front seat valves is that the charge port on the valves is always in direct communication with the system&#39;s refrigerant. In order to seal the refrigerant inside the system while its charge port cap is removed, another component, a valve core, must be installed in the charge port. The valve core can then be actuated by an appropriate fitting to allow for evacuation or addition of refrigerant as well as for pressure measurement. The required time to evacuate or add refrigerant is increased with a valve core due to its inherent flow restrictions.  
           [0009]    A further style of service valve used in residential air-conditioning and heat pump service valve applications is a backseat valve. The system&#39;s refrigerant is sealed away from the backseat valve&#39;s charge port (by back seating the valve) so that no valve core is needed in the charge port. However, a typical backseat valve is a more expensive when compared to standard front seat valves.  
         SUMMARY OF THE INVENTION  
         [0010]    The present invention provides improvements in service valve assemblies which overcome one or more of the aforesaid obstacles met with prior art service valve assemblies.  
           [0011]    According to one feature of the present invention, a service valve assembly, for use in a split air conditioning/heat pump system, is provided with a single valve block having a plurality of passages, a first valve and a second valve. The assembly further includes a first cavity within the block with a first valve holding passage, for conducting gaseous refrigerant inside the valve block. The first valve is operatively positioned within the first valve holding passage and includes a first through passage radially extending both through the first valve as well as from an outer surface of a first side of the block to an outer surface of a side opposite the first side. A first charging passage extends from the valve block outer surface to the first through passage. The valve block also includes a second cavity, including a second valve holding passage, for conducting liquid refrigerant within the block. The second valve is operatively interposed within the second valve holding passage and includes a second through passage extending both through the second valve as well as from the outer surface of the valve block first side to the outer surface of the opposite side. A second charging passage extends from the valve block outer surface to the second through passage. The first valve is adapted for receiving and fluidly communicating the gaseous refrigerant between the first through passage and the first charging passage. The second valve is adapted for receiving and fluidly communicating the liquid refrigerant between the second through passage and the second charging passage.  
           [0012]    Another feature of the noted valve assembly has a first indoor unit port connected to a first end of the first through passage and a first outdoor unit port connected to a second end of the first through passage. A first service port is connected to the first charging passage and a first valve actuation port is connected to the first valve holding passage. A second outdoor unit port is connected to a first end of the second through passage and a second indoor unit port is connected to a second end of the second through passage. A second service port is connected to the second charging passage and a second valve actuation port is connected to the second valve holding passage. Yet another feature has the first and second actuation ports formed integrally with the valve block.  
           [0013]    Still another feature of the noted service valve assembly has a first charging valve cap for covering the first service port and a second charging port cap for covering the second service port. A first valve cap covers the first valve actuation port and a second valve cap covers the second valve actuation port. Another aspect of the noted assembly has the first through passage, the first valve holding passage, the second through passage, and the second valve holding passage being circular in cross section and of differing diametral extent.  
           [0014]    A further feature of the noted service valve assembly has the first charging passage and the first valve holding passage being oriented perpendicularly relative to the first through passage. Also, the second charging passage and the second valve holding passage can be oriented perpendicularly relative to the second through passage. Still another feature has the valve block with a surface having at least one recess for receiving a fastening member for securing the assembly onto a component of the system.  
           [0015]    Still yet another feature of the noted service valve has the first through passage being linear. Another feature has the second through passage being linear. Still another has both the first and second through passages being linear. Another aspect has the first valve with at least one seal for retaining gaseous refrigerant with the first plurality of passages. This at least one seal can be comprised of an elastomeric material.  
           [0016]    According to yet another aspect of the invention, the first valve can be a plug valve. Still according to this aspect of the invention, the plug valve has a plug body capable of housing a series of removable stems with through holes of varying diameters. Still the plug valve can have a seal for retaining refrigerant with the first through passage. Still yet, the plug valve can have an isolated charge port.  
           [0017]    A further feature of the noted valve assembly has the first and second valves being plug valves. Another feature has the plug valves with different sizes. Still another feature has the plug valves having a valve stem which can be replaced with a substitute valve stem having an alternate sized through passage. Yet another feature has each of the plug valve with an isolated charge port. Yet another aspect of the invention has the first valve as a plug valve and the second valve as a front seat valve. Further features and advantages of the present invention will become apparent to those skilled in the art upon review of the following specification in conjunction with the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]    [0018]FIG. 1 is a perspective view of one embodiment of the service valve assembly according to the present invention.  
         [0019]    [0019]FIG. 2 is a top plan view of the service valve assembly shown in FIG. 1.  
         [0020]    [0020]FIG. 3 is a sectional view taken along line  3 - 3  in FIG. 2.  
         [0021]    [0021]FIG. 4 is a side view of the service valve assembly of FIG. 1.  
         [0022]    [0022]FIG. 5 is a sectional view taken along line  5 - 5  in FIG. 4.  
         [0023]    [0023]FIG. 6 is a schematic of the service valve assembly integrated into a split air conditioning/heat pump system.  
         [0024]    [0024]FIG. 7 a  is a perspective view of a valve stem used in the present invention.  
         [0025]    [0025]FIG. 7 b  is a sectional view taken along line  7   b - 7   b  in FIG. 7 a.    
         [0026]    [0026]FIG. 7 c  is a sectional view taken along line  7   c - 7   c  in FIG. 7 a.    
         [0027]    [0027]FIG. 7 d  is a further perspective view of the valve stem shown in FIG. 7 a  with the addition of a directional cap.  
         [0028]    [0028]FIG. 7 e  is a side view, with phantom seal groove lines shown, of the valve stem of the present invention.  
         [0029]    [0029]FIG. 8 is an elevated view of an end cap used for sealing an opening in the service valve assembly.  
         [0030]    [0030]FIG. 9 is an elevated view of a rotational restriction member used for limiting the extent of rotational movement when manually operating the valve stem.  
         [0031]    [0031]FIG. 10 is an elevational view of another embodiment of the service valve assembly according to the present invention.  
         [0032]    [0032]FIG. 11 is a side view of the service valve assembly shown in FIG. 10.  
         [0033]    [0033]FIG. 12 is a sectional view taken along line  12 - 12  in FIG. 11.  
         [0034]    [0034]FIG. 13 is an elevational view of a further embodiment of the service valve assembly according to the present invention.  
         [0035]    [0035]FIG. 14 is an elevational view of an additional embodiment of the service valve assembly according to the present invention.  
         [0036]    [0036]FIG. 15 is a top plan view of the service valve assembly shown in FIG. 14.  
         [0037]    [0037]FIG. 16 is a sectional view taken along line  16 - 16  in FIG. 15. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0038]    Referring first to FIGS. 1-6, one embodiment dual body service valve assembly  5  is shown. Service valve assembly  5  has a valve body  10  that is preferably machined from bar stock, e.g. square bar stock, and provides fluid connections for an indoor unit  80  (FIG. 6) and an outdoor unit  90  used, for example, in a residential split air-conditioning/heat pump system. As is well known in the art, service valve assemblies provide connections between a charging apparatus and a condensing unit, as well as between outdoor and indoor units. While functioning as an air-conditioning system, outdoor unit  90  is primarily comprised of a compressor  92 , an outdoor coil  94  and a fan  96 . Indoor unit  80  is primarily comprised of an expander  82 , an indoor coil  84  and a fan  86 . Once installed, outdoor unit  90  is connected with indoor unit  80  by a high-pressure line  74   a ,  74   b  and a low-pressure line  75   a ,  75   b  that convey a refrigerant medium.  
         [0039]    Valve body  10  has multiple adjacent sides that are positioned to most directly communicate with other components in the system. For example, since valve body  10  is providing a connection between outdoor unit  90  and indoor unit  80 , conduit  74   a , that attaches same to outdoor unit  90 , mates with a first side  12  of valve body  10  and conduit  74   b  that attaches same to indoor unit  80  mates with a second side  13  of valve body  10 . A suction end  15  is located on one axial end of valve body  10 , with a liquid end  35  being located on the opposite axial end thereof. Suction end  15  incorporates a suction valve cavity  16  that also includes machined interconnectable passages within valve body  10 . At its furthest axial end, suction valve cavity  16  is structured to receive a suction service valve, or valve plug  18 , shown in FIG. 7 a . Valve body  10 , at suction end  15 , also includes a formed suction end port  17  that can be threaded to receive a correspondingly threaded cap  30 .  
         [0040]    Likewise, liquid end  35  incorporates a liquid valve cavity  36  that also includes machined interconnectable passages with valve body  10 . Liquid valve cavity  36 , and its passages, are not connected with suction valve cavity  16 , at its associated passages. At its furthest axial end, liquid valve cavity  36  is structured to receive a liquid service valve that can take, if so desired, a form similar to that of valve plug  18 , or alternatively a liquid service valve, or valve stem  38 , as shown in FIG. 3. If used, valve stem  38  can take the form of either a front seating valve or other well know valves used in the noted outdoor residential equipment. Valve body  10 , at liquid end  35 , also includes a formed liquid end port  37  that can be threaded to receive a correspondingly threaded cap  41 .  
         [0041]    Suction end cavity  16  includes a radial through passage  21  that extends from first side  12  to second side  13 . As shown in FIG. 5, suction through passage  21  is linear or in-line so that it can receive valve plug  18 . Similarly, liquid end cavity  36  has a radial through passage  39  that also extends from first side  12  to second side  13 . However, in the embodiment shown in FIG. 5, liquid through passage  39  is not linear, but is stepped or off-set so that the machined surface of passage  39 , within cavity  36 , can provide a front seat, sealing shoulder  42  for valve stem  38 . As referenced earlier, in the alternative, through passage  39  could be structured to be linear, like passage  21 , and also receive a valve plug  18 . In that latter case, liquid end  35  could be substantially a mirror image of the shape of suction end  15 . Of course, suction passages and their valves are typically larger than the liquid passages and their valves since the suction passages are conveying gaseous rather than liquid refrigerant.  
         [0042]    Valve body  10  interfaces with outdoor unit  90  via an orifice  19  (FIG. 5) on first side  12  that connects with an inlet tube  20  which conveys gaseous refrigerant to outdoor unit  90 . Valve body  10  further interfaces with outdoor unit  90  via another orifice  23  on first side  12  that receives a condensing side tube  26  which receives liquid refrigerant from outdoor unit  90  during the working cycle. This direction of fluid flow would, of course, be reversed during the heating cycle. Valve body  10  has a side mounting surface  63  that has at least one mounting hole (not shown) machined into surface  63  so that valve body  10  can be mounted onto, for example, the condensing unit.  
         [0043]    Valve body  10  further has two more orifices (FIG. 5) located on second side  13  that provide an interface with indoor unit  80 . A first orifice  43  receives an inlet tube  44  that conveys liquid refrigerant to indoor unit  80  and a second orifice  47  receives a suction, or low-pressure side, tube  48  that accepts gaseous refrigerant from indoor unit  80 . It should be noted that tubes  20 ,  26 ,  44  and  48  can be permanently attached to valve body  10 , e.g. with brazed joints or formed integrally with valve body  10 .  
         [0044]    Suction end conduits  20 ,  48  are aligned on opposite sides  12 ,  13  of valve body  10 , and are positioned at the same axial end, namely suction end  15 . A suction end charge port  52  is also positioned at suction end  15  on a body side surface  14  between conduit  20  and  48 . A removable charge port cap  54  is attached to charge port  52  and seals refrigerant medium inside suction end  15  of service valve assembly  5 . Suction service valve  18  can fluidly communicate with charge port  52  via a radial side passage  28 , as well as suction conduit  20 ,  48  via a radial through passage  27 .  
         [0045]    Similarly, liquid end conduit  26 ,  44  are positioned on opposite sides  12 ,  13  of valve body  10 , and are located at the same axial end, namely liquid end  35 . A liquid end charge port  56  is also positioned at liquid end  35  on side surface  14  between conduit  26  and  44 . As previously referenced, since the suction side service valve  18  and conduit  20 ,  48  convey gaseous (lower pressure) refrigerant, valve  18  is shown substantially larger than the liquid side service valve  38 . A removable liquid end charge port cap  58  is attached to charge port  56  and seals refrigerant medium inside liquid end  35  of service valve assembly  5 .  
         [0046]    Referring now to FIGS. 7-9, suction side service valve  18  is generally cylindrical and has major radial through passage  27  and an intersecting minor radial side passage  28  integrated therewithin. At least one or preferably two O-ring grooves  22  are positioned on at least one axial end of valve  18  and receive O-rings (not shown) whose function is the sealing of valve  18  within its receiving cavity  16  in valve body  10 . These O-rings can be comprised of known elastomeric materials that act as good sealants for retarding refrigerant progression while withstanding its deleterious effects. A valve actuation stem  24  is located on one longitudinal end and is used for rotating service valve  18  to open and closed positions. A direction-indicating cap  32  is placed on top of stem  24  and provides an indication of the position of valve  18 . A rotational restriction member  25  is pressed into cavity  16  on top of suction service valve  18  and limits the extent of the rotation of stem  24 . For example, if service valve  18  has an isolated charge port orifice (as is shown at  28  in FIG. 7 a ), the valve rotation will be restricted to 270°. If service valve  18  does not have an isolated charge port, the rotational extent will be restricted to 90°. When operatively received within its valve cavity  16 , suction valve actuation stem  24  and directional cap  32  protrude outwardly from suction end port  17 . As is best shown in FIG. 5, major passage  27  extends through service valve  18  and fluidly connects inlet tube  20  with suction tube  48  when service valve  18  is rotated for gaseous refrigerant passage. Isolated charge port orifice or minor passage  28  is formed within service valve  18  and extends from the outer surface of service valve  18  to major passage  27 . As is best seen in FIG. 3, minor passage  28  aligns with suction end charge port  52  when properly rotated, with the latter serving for charging and diagnostic purposes.  
         [0047]    The seal(s), or O-ring(s) (not shown), within suction service valve grooves  22  prevent refrigerant from reaching suction end charge port  52  when service valve  18  is rotated such that minor passage  28  is not aligned with charge port  52 . The seal(s) also prevent refrigerant from reaching inlet tube  20  when major passage  27  is not aligned with inlet tube  20  and suction tube  48 . This non-alignment valve position is common during shipment of outdoor unit  90  before installation or after a pump down procedure when it is desired to prevent refrigerant flow between the outdoor and indoor units. Suction valve port end  17  is preferably permanently deformed to capture rotational restriction member  25  and suction service valve  18 . Cap  30  encapsulates suction service valve  18 , as a final seal against leakage, and can be threadably connected with suction valve port  17 .  
         [0048]    It should again be noted that liquid end  35  could use a service valve similar to suction service valve  18 . This of course would alter the design of valve body  10  as shown in FIGS. 1-5. Specifically, liquid through passage  39  would be linear, like suction through passage  21 . Alternatively, as shown in FIGS. 1-5, liquid service valve  38  can be used. Liquid valve port  37  is preferably permanently deformed to capture liquid service valve  38 . Preferably the external surface of liquid valve port  37  is threaded to mate with corresponding threads on a cap  41 . As discussed above, liquid service valve  38  is shown as a front-seating valve. As is well known in the art, a front-seating valve is actuated by multiple rotational threading that produces linear movement. Specifically, valve  38  is threaded into liquid valve cavity  36  so it moves linearly in or out of liquid through passage  39  with manual rotation. When completely threaded into passage  39 , the distal end of valve  38  engages machined shoulder  42  which in turn prevents refrigerant from passing from one end of passage  39  to the other.  
         [0049]    [0049]FIGS. 10-12 show another embodiment valve body  110  in which liquid valve port  37  is once again formed or machined directly onto one end of the valve body, similar to valve body  10  discussed above. Suction side valve end  15  has been modified from that of valve body  10  such that the placement of charge port  52  and suction valve port  17  have been reversed. As discussed above, suction valve port  17  once again houses actuation stem  24  of valve  18 , along with rotational restriction member  25  and cap  30 . As with embodiment  10 , suction end charge port  52  is positioned between conduit  20  and  48 , specifically at 90° from through passage  21 . Additionally, valve port  17  is also positioned at 90° from through passage  21 . The operation and assembly of suction service valve  18  is identical to embodiment  10  discussed above. It should also be noted that valve body  110  could be formed with suction valve port  16  being part of one-piece valve body  110 .  
         [0050]    [0050]FIG. 13 details a further embodiment valve body  210  in which suction and liquid valve ports  17 ,  37  are individually machined components brazed onto valve body  210  during assembly. Suction end  15  is identical to suction end of valve body  110  shown in FIG. 10. Liquid end  35  has been modified from valve body  110  in that the location of liquid valve port  37  and liquid charge port  56  are reversed. The cavity within liquid end  35  once again receives liquid service valve  38  similar to that of valve body  10 . Once again, suction end charge port  52  is positioned at 90° from through passage  21  (not shown). Additionally, suction end port  17  is also positioned at 90° from through passage  21 . Liquid end charge port  56  is positioned on a surface between condensing side tube  26  and inlet tube  44  and is oriented at 90° from passage  39  (not shown). Liquid end port  37  is also oriented at 90° from passage  39 . The operation and assembly of suction service valve  18  is identical to embodiment  10  discussed above. Embodiment  210  discloses a three-piece (valve body  210 , suction valve port  16  and liquid valve port  36 ) construction, but a one-piece construction could be employed by integrally forming valve body  210  with the additional ports  16 ,  36 , as is the case with valve body  10 .  
         [0051]    [0051]FIGS. 14-16 detail yet an additional embodiment valve body  310  in which suction valve port  17  is machined directly into valve body  310  (as is the case in previously discussed valve body  10 ). Inlet tube  20  and suction tube  48  are also similar to those of previously discussed valve body  10 . Liquid end  35  has been altered so that a mounting surface  65  is available at the axial end opposite suction end  15 . At least one mounting hole  67  is machined into mounting surface  65  so that valve body  310  can be mounted in an upright manner. When compared with valve body  10 , liquid valve port  37  has been moved from the furthermost axial surface, mounting surface  65 , of the valve body to an adjacent surface located between condensing side tube  26  and inlet tube  44 . This embodiment shows liquid valve port  37  as a separate machined port that is preferably brazed onto valve body  310 . Suction end  52  and liquid end  56  charge ports are similar to those shown with valve body  10 . As with every other embodiment, suction end port  17  and suction end charge port  52  are positioned at 90° from suction through passage  21  (not shown). Similarly, liquid end port  37  and liquid end charge port  56  are also positioned at 90° from liquid through passage  39  (not shown).  
         [0052]    It should be noted that each one of valve body embodiments  110 ,  210  and  310  can utilize valve  18  as a substitute for the shown liquid service valve  38 . In each such case, liquid through passage  39  would take the form of a linear passage similar to suction through passage  21  and receive valve plug  18 .  
         [0053]    It should be noted that the present invention is not limited to the specified preferred embodiments and principles. Those skilled in the art to which this invention pertains may formulate modifications and alterations to the present invention. These changes, which rely upon the teachings by which this disclosure has advanced, are properly considered within the scope of this invention as defined by the appended claims.