Abstract:
A scroll compressor having a housing with a motor-compressor unit disposed therein. The motor-compressor unit includes a crankcase, stator, rotor, and drive shaft assembly. The motor-compressor unit further includes a fixed scroll member and an orbiting scroll member. The scroll compressor has a separator plate disposed within the housing and secured to the fixed scroll member by a plurality of fasteners. A seal member is provided between the separator plate and the fixed scroll member and is disposed radially outwardly of at least one of the fasteners. In an exemplary embodiment, the seal member is an O-ring.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to scroll machines, and in particular, to scroll compressors.  
         [0003]     2. Description of the Related Art  
         [0004]     Referring to  FIGS. 1-4 , a known scroll compressor  10  is shown, which includes main housing  12 , bottom cap  14  with base  16  secured to the lower end of housing  12 , and a separator plate  18  and top cap  20  each secured to the upper end of housing  12  by a welding, brazing, or other suitable operation to define an enclosed hermetic housing in which the motor-compressor unit  22  of compressor  10  is disposed. Motor-compressor unit  22  generally includes a first, fixed scroll  24 , a second, orbiting scroll  26 , crankcase  28 , drive shaft  30 , stator  32 , rotor  34 , and outboard bearing assembly  36 . Separator plate  18  is secured around its perimeter to the interior of housing  12 , such as by welding, and divides the interior of the housing  12  into a suction chamber  38  in fluid communication with suction port  40  in housing  12 , and discharge chamber  42  in fluid communication with discharge port  44  in top cap  20 . Scroll compressor  10  is similar to the scroll compressor discussed in detail in U.S. Patent Application Publication No. US 2004/0047754 A1, application Ser. No. 10/235,214, entitled OIL SHIELD AS PART OF CRANKCASE FOR A SCROLL COMPRESSOR, filed on Sep. 5, 2002, assigned to the assignee of the present invention, the disclosure of which is expressly incorporated herein by reference.  
         [0005]     Fixed scroll  24  is secured to separator plate  18 , such as by a plurality of bolts  72  disposed radially outwardly of separator plate hole  19 , and includes outer wall  46  extending from base plate  48 , and an involute wrap  50  extending from base plate  48  and disposed inwardly of outer wall  46 . Fixed scroll  24  further includes a plurality of mount flanges  52  spaced radially about the end of outer wall  46  opposite base plate  48 , and a plurality of bolts (not shown) secure mount flanges  52  to crankcase  28 . Crankcase  28  includes main bearing  54  in which the upper portion of drive shaft  30  is rotatably supported. Stator  32  is fixed within housing  12  and is connected to outboard bearing assembly  36  and crankcase  28  in a suitable manner. Drive shaft  30  is secured to rotor  34  in a suitable manner, and outboard bearing assembly  36  includes outboard bearing  56  which supports a lower end of drive shaft  30 . The upper portion of drive shaft  30  includes an eccentric end mounted within annular hub  58  extending downwardly from base plate  60  of orbiting scroll  26 . Orbiting scroll  26  additionally includes an involute wrap  62  extending upwardly from base plate  60  thereof, which is in meshing relationship with wrap  50  of fixed scroll  24 . Oldham coupling  64  is operatively coupled between orbiting scroll  26  and crankcase  28  to prevent rotation of orbiting scroll  26 , as is known.  
         [0006]     Additionally, fixed scroll  24  includes discharge outlet  68  in base plate  48 . Discharge outlet  68  may be substantially centrally located within fixed scroll  24  and may be aligned with separator plate hole  19  of separator plate  18 .  
         [0007]     In operation, electrical energization of stator  32  rotatably drives rotor  34  and drive shaft  30  to move orbiting scroll  26  in an orbiting manner with respect to fixed scroll  24 . A working fluid at suction pressure is drawn from suction chamber  38  into a suction inlet  66  of fixed scroll  24 , and is compressed within the plurality of variable volume, working pockets or compression chambers  55  which are defined between wraps  50  and  62  of fixed and orbiting scrolls  24  and  26 , respectively, as orbiting scroll  26  rotates in a known manner. The compressed working fluid is then discharged through discharge outlet  68  in base plate  48  of fixed scroll  24 , through discharge check valve assembly  70 , and through separator plate hole  19  aligned with discharge outlet  68  into discharge chamber  42  at a discharge pressure. The discharge pressure working fluid exits compressor  10  through discharge port  44  to enter components of a refrigeration system (not shown).  
         [0008]     Referring to  FIGS. 2-4 , gasket  74  ideally prevents potential leakage of discharge pressure working fluid from exiting discharge chamber  42  and returning to suction chamber  38 , such as via a path denoted by Arrow C, shown in  FIG. 4 . However, a minimal gap may exist between separator plate  18  and gasket  74 , or alternatively between fixed scroll  24  and gasket  74 , which may permit discharge pressure working fluid to escape to suction chamber  38 . Discharge pressure working fluid potentially may also leak around bolts  72  in a direction generally denoted by Arrow A and return to suction chamber  38  via the minimal gap denoted by Arrow C between separator plate  18  and gasket  74 , or alternatively between fixed scroll  24  and gasket  74 . Additionally, discharge pressure working fluid potentially may enter the gap denoted by Arrow C between separator plate  18  and gasket  74 , or alternatively between fixed scroll  24  and gasket  74 , via a path through separator plate hole  19  denoted by Arrow B. Once discharge pressure working fluid enters the gap denoted by Arrow C, the working fluid may enter suction chamber  38  in the direction generally denoted by Arrow D.  
         [0009]     Additionally, internal pressure relief valve (IPRV)  76  is disposed in and threaded into separator plate  18 , as shown in  FIG. 3 . IPRV  76  allows discharge pressure working fluid to be vented from discharge chamber  42  to suction chamber  38  in the event of overpressurization. IPRV  76  is accommodated in a recess formed near the outer periphery of fixed scroll  24 . Consequently, gasket  74 , which is designed to seal fixed scroll  24  and separator plate  18 , is notched to a reduced width to clear IPRV  76 . Therefore, the robustness of gasket  74  is undermined in the area around IPRV  76 .  
         [0010]     The above-described potential leak paths potentially reduce the efficiency of scroll compressor  10 , thereby lowering productivity of the refrigeration system as a whole.  
         [0011]     What is needed is a scroll compressor which is an improvement over the foregoing.  
       SUMMARY OF THE INVENTION  
       [0012]     The present invention provides a scroll compressor having a housing with a motor-compressor unit disposed therein. The motor-compressor unit includes a crankcase, stator, rotor, and drive shaft assembly. The motor-compressor unit further includes a fixed scroll member and an orbiting scroll member. The scroll compressor has a separator plate disposed within the housing and secured to the fixed scroll member by a plurality of fasteners. A seal member is provided between the separator plate and the fixed scroll member and is disposed radially outwardly of at least one of the fasteners. In an exemplary embodiment, the seal member is an O-ring.  
         [0013]     An advantage of the present invention is the complete prevention of discharge pressure working fluid leakage from a discharge chamber to a suction chamber of the scroll compressor, thereby enhancing productivity of the entire refrigeration system.  
         [0014]     In one form thereof, the present invention provides a scroll compressor including a housing; a motor-compressor unit disposed within the housing, including a crankcase and a stator, rotor, and drive shaft assembly, the drive shaft rotatably supported by the crankcase, the motor-compressor unit further including a first scroll member fixed with respect to the housing and defining perpendicular axial and radial directions, the first scroll member including a base wall and a first wrap extending from the base wall; and a second scroll member coupled to the drive shaft for orbital movement, the second scroll member including a second wrap intermeshed with the first wrap; a separator plate disposed within the housing and secured to the first scroll member by a plurality of fasteners; and a seal member between the separator plate and the first scroll member, the seal member disposed radially outwardly of at least one of the fasteners.  
         [0015]     In another form thereof, the present invention provides a scroll compressor including a housing; a motor-compressor unit disposed within the housing, including a crankcase and a stator, rotor, and drive shaft assembly, the drive shaft rotatably supported by the crankcase, the motor-compressor unit further including a first scroll member fixed with respect to the housing and defining perpendicular axial and radial directions, the first scroll member including a base wall having a discharge outlet located substantially centrally therein, and a first wrap extending from the base wall; and a second scroll member coupled to the drive shaft for orbital movement, the second scroll member including a second wrap intermeshed with the first wrap; a separator plate disposed within the housing and including an opening aligned with the discharge outlet, the separator plate secured to the first scroll member by a plurality of fasteners disposed radially outwardly of the opening; and a continuous seal member captured between the separator plate and the first scroll member, the seal member disposed radially outwardly of the fasteners.  
         [0016]     In a further form thereof, the present invention provides a scroll compressor including a housing; a motor-compressor unit disposed within the housing including a crankcase; a stator, rotor, and drive shaft assembly, the drive shaft rotatably supported by the crankcase; a first scroll member fixed with respect to the housing and defining perpendicular axial and radial directions, the first scroll member including a base wall and a first wrap extending from the base wall; and a second scroll member coupled to the drive shaft for orbital movement, the second scroll member including a second wrap intermeshed with the first wrap; a separator plate disposed within the housing and dividing the housing into a suction chamber and a discharge chamber, the separator plate secured to the first scroll member by a plurality of fasteners; and sealing means between the separator plate and the first scroll member to prevent passage of a working fluid therebetween. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]     The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:  
         [0018]      FIG. 1  is a vertical sectional view through a known scroll compressor;  
         [0019]      FIG. 2  is a fragmentary portion of  FIG. 1 , further illustrating an internal pressure relief valve;  
         [0020]      FIG. 3  is a perspective view of a fixed scroll of the known scroll compressor of  FIG. 1 , further showing a fragmentary portion of the separator plate;  
         [0021]      FIG. 4  is a close-up view of a portion of  FIG. 2 ;  
         [0022]      FIG. 5  is a fragmentary portion of  FIG. 1 , further illustrating a seal member in accordance with the present invention;  
         [0023]      FIG. 6  is a perspective view of a fixed scroll of the scroll compressor of  FIG. 5 , further showing a fragmentary portion of the separator plate;  
         [0024]      FIG. 7  is a close-up view of a portion of  FIG. 5 ;  
         [0025]      FIG. 8  is a fragmentary portion of  FIG. 1 , further illustrating a seal member and an internal pressure relief valve in accordance with the present invention; and  
         [0026]      FIG. 9  is a fragmentary portion of  FIG. 1 , further illustrating a seal member and an alternative placement of an internal pressure relief valve in accordance with the present invention. 
     
    
       [0027]     Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates one preferred embodiment of the invention, in one form, and such exemplification is not to be construed as limiting the scope of the invention in any manner.  
       DETAILED DESCRIPTION  
       [0028]     Referring to  FIG. 5 , scroll compressor  110  is shown in partial view, which includes main housing  12 , bottom cap  14  with base  16  ( FIG. 1 ) secured to the lower end of housing  12 , and a separator plate  18  and top cap  20  each secured to the upper end of housing  12  by a welding, brazing, or other suitable operation to define an enclosed hermetic housing in which the motor-compressor unit  22  ( FIG. 1 ) of compressor  110  is disposed. Except as described below, compressor  110  includes many features identical or substantially identical to those of scroll compressor  10  described above, and the same reference numerals are used in  FIGS. 5-9  to denote identical or substantially identical features therebetween.  
         [0029]     Scroll compressor  110  further includes a first, fixed scroll  24  and a second, orbiting scroll  26 . Fixed scroll  24  is fixed with respect to housing  12  and defines perpendicular axial and radial directions. The axial direction of fixed scroll  24  is aligned with the central, longitudinal axis of housing  12 . Separator plate  18  is secured around its perimeter to the interior of housing  12 , such as by welding, and divides the interior of the housing  12  into a suction chamber  38  in fluid communication with suction port  40  ( FIG. 1 ) in housing  12 , and discharge chamber  42  in fluid communication with discharge port  44  in top cap  20 .  
         [0030]     Referring now to  FIGS. 5 and 6 , fixed scroll  24  is secured to separator plate  18 ,. such as by a plurality of fasteners or bolts  72  extending in the axial direction, and includes outer wall  46  extending from base wall or plate  48 , and an involute wrap  50  extending from base plate  48  and disposed inwardly of outer wall  46 . Fixed scroll  24  further includes a plurality of mount flanges  52  ( FIG. 1 ) spaced radially about the end of outer wall  46  opposite base plate  48 , and a plurality of bolts secure mount flanges  52  to crankcase  28  ( FIG. 1 ). Orbiting scroll  26  includes an involute wrap  62  extending upwardly from base plate  60  ( FIG. 1 ) thereof, which is in meshing relationship with wrap  50  of fixed scroll  24 . Oldham coupling  64  ( FIG. 1 ) is operatively coupled between orbiting scroll  26  and crankcase  28  to prevent rotation of orbiting scroll  26 , as is known.  
         [0031]     The operation of scroll compressor  110  is substantially similar to that described above for scroll compressor  10  and is not described further herein.  
         [0032]     Referring now to  FIG. 6 , fixed scroll  24  includes annular groove  77  formed in top surface  25  thereof and located radially outwardly of fasteners  72 . Groove  77  accommodates seal member or O-ring  78  and may take any cross-sectional shape including semi-circular, rectilinear (as shown in  FIG. 7 ), or semi-oval shapes. Similarly, seal member  78  may be any shape such as a circular, oval, square, rectilinear, or irregular shape.. Seal member  78  preferably extends a distance above top surface  25  of fixed scroll  24  and is captured under compression between separator plate  18  and fixed scroll  24 . More specifically, separator plate  18  compresses seal member  78  upon the torque of fasteners  72  when separator plate  18  is attached to fixed scroll  24  to form a fluidtight seal between separator plate  18  and fixed scroll  24 . Seal member  78  may be continuous or, alternatively, may be broken into a plurality of separate components.  
         [0033]     The fluidtight seal between separator plate  18  and fixed scroll  24  prevents leakage of discharge pressure working fluid from discharge chamber  42  into suction chamber  38 . Advantageously, the fluidtight seal is radially outside the perimeter of fasteners  72  such that, even if leakage were to occur around fasteners  72 , seal member  78  would prevent the discharge pressure working fluid from entering suction chamber  38 .  
         [0034]     In an alternative embodiment (not shown), separator plate  18  may include an annular groove located in a bottom surface thereof to accommodate seal member or O-ring  78 . Seal member  78  would preferably extend a distance below the bottom surface of separator plate  18  and be captured under compression between separator plate  18  and fixed scroll  24  to form a fluidtight seal between separator plate  18  and fixed scroll  24 .  
         [0035]     In another alternative embodiment (not shown), both separator plate  18  and fixed scroll  24  may each include annular grooves to accommodate seal member or O-ring  78 . Seal member  78  would be captured under compression between separator plate  18  and fixed scroll  24 . Separator plate  18  and fixed scroll  24  compress seal member  78  upon torque of fasteners  72  when separator plate  18  is attached to fixed scroll  24  to form a fluidtight seal between separator plate  18  and fixed scroll  24 .  
         [0036]     Referring now to  FIG. 8 , scroll compressor  110  is provided with internal pressure relief valve (IPRV)  79  which allows discharge pressure working fluid to be vented from discharge chamber  42  to suction chamber  38  in the event of overpressurization. IPRV  79  selectively fluidly communicates discharge chamber  42  with suction chamber  38 . IPRV  79  is threaded within bore  80  formed in fixed scroll  24  at an acute angle relative to the central longitudinal axis of fixed scroll  24 . Inlet end  81  of IPRV  79  is threaded into a portion of bore  80  and is thus advantageously located inside the sealed space defined by seal member  78 . Inlet end  81  of IPRV  79  is in fluid communication with discharge chamber  42 . Outlet end  82  of IPRV  79  is in fluid communication with suction chamber  38 . Therefore, IPRV  79  may be subassembled into fixed scroll  24 , and the fluidtight seal between fixed scroll  24  and separator plate  18  provided by seal member  78  is unaffected.  
         [0037]     Referring now to  FIG. 9 , scroll compressor  110  is provided with an alternate placement of IPRV  79 . IPRV  79  is disposed in bore  85  formed in separator plate  18  radially outwardly of fixed scroll  24 . Inlet end  83  of IPRV  79  is threaded into bore  85  and is in fluid communication with discharge chamber  42 . Outlet end  84  of IPRV  79  is in fluid communication with suction chamber  38 . By locating IPRV  79  radially outwardly of fixed scroll  24 , the fluidtight seal between fixed scroll  24  and separator plate  18  provided by seal member  78  is unaffected.  
         [0038]     While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.