Abstract:
A compressor may include a shell, a compression mechanism, a crankshaft, a bearing support, and a lubricant sump. The compression mechanism may be disposed in the shell and may compress a working fluid. The crankshaft may be disposed at least partially in the shell and may drivingly engage the compression mechanism. The bearing support may rotatably support the crankshaft. The lubricant sump may retain a volume of lubricant and may be disposed between the bearing support and the compression mechanism.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 12/776,773, filed on May 10, 2010, which claims the benefit of U.S. Provisional Application No. 61/178,720, filed on May 15, 2009. The entire disclosures of the above applications are incorporated herein by reference. 
     
    
     FIELD 
       [0002]    The present disclosure relates generally to compressor machines. More particularly, the present disclosure relates to a compressor and an oil-cooling system that cools the lubricating oil that flows through the compressor. 
       BACKGROUND 
       [0003]    Compressor machines in general, and particularly scroll compressors, are often disposed in a hermetic or semi-hermetic shell which defines a chamber within which is disposed a working fluid. A partition within the shell often divides the chamber into a discharge-pressure zone and a suction-pressure zone. In a low-side arrangement, a scroll assembly is located within the suction-pressure zone for compressing the working fluid. Generally, these scroll assemblies incorporate a pair of intermeshed spiral wraps, one or both of which are caused to orbit relative to the other so as to define one or more moving chambers which progressively decrease in size as they travel from an outer suction port towards a center discharge port. An electric motor is normally provided which operates to cause this relative orbital movement. 
         [0004]    The partition within the shell allows compressed fluid exiting the center discharge port of the scroll assembly to enter the discharge-pressure zone within the shell while simultaneously maintaining the integrity between the discharge-pressure zone and the suction-pressure zone. This function of the partition is normally accomplished by a seal which interacts with the partition and with the scroll member defining the center discharge port. 
         [0005]    The discharge-pressure zone of the shell is normally provided with a discharge-fluid port which communicates with a refrigeration circuit or some other type of fluid circuit. In a closed system, the opposite end of the fluid circuit is connected with the suction-pressure zone of the shell using a suction-fluid port extending through the shell into the suction-pressure zone. Thus, the scroll machine receives the working fluid from the suction-pressure zone of the shell, compresses the working fluid in the one or more moving chambers defined by the scroll assembly, and then discharges the compressed working fluid into the discharge-pressure zone of the compressor. The compressed working fluid is directed through the discharge port through the fluid circuit and returns to the suction-pressure zone of the shell through the suction port. 
         [0006]    A lubricant (e.g., oil) sump can be employed in the shell of the compressor to store the lubricant charge. The sump can be placed in either the low-pressure zone or the high-pressure zone. The lubricant serves to lubricate the moving components of the compressor and can flow with the working fluid through the scroll assemblies and be discharged along with the working fluid into the discharge-pressure zone of the compressor. The temperature of the lubricant being discharged, along with that of the working fluid, is elevated. Cooling the lubricant prior to flowing back through the compressor and lubricating the components therein can reduce suction-gas superheat, thereby improving compressor volumetric efficiency and providing better performance. The reduced lubricant temperature may also improve compressor reliability by cooling the suction gas and the motor. Cooling the lubricant can also keep the viscosity of the lubricant at a desirable level for maintaining oil film thickness between moving parts. 
         [0007]    Within the compressor, the lubricant is provided to the various moving components. Improving the distribution of the lubricant throughout the compressor can advantageously improve the performance and/or longevity of the compressor. 
         [0008]    Within the compressor, the proper alignment of the various components relative to one another can improve the performance of the compressor and/or reduce the sound generated by the compressor. Improving the alignment between the various components, such as the non-orbiting scroll member, the bearings, and the motor, can improve the performance and/or reduce the sound generated by the compressor. The compressors typically use numerous discrete components that are assembled together within the shell to provide the alignment. The use of these numerous separate and discrete components, however, increases the potential for inaccuracy in the alignment of the components and, further, can be more expensive or time consuming to manufacture as tighter tolerances for the various components are required to produce the desired alignment. 
       SUMMARY 
       [0009]    In one form, the present disclosure provides a system that may include a compressor, a lubricant, a condenser, an expansion device, and a heat exchanger. The compressor may compress a working fluid from a suction pressure to a discharge pressure greater than the suction pressure. The lubricant may lubricate the compressor. The condenser may condense working fluid discharged by the compressor. The expansion device may expand working fluid condensed by the condenser. The heat exchanger may transfer heat from the lubricant to expanded working fluid. 
         [0010]    In another form, the present disclosure provides a compressor that may include a shell, a compression mechanism, a crankshaft, a bearing, and a lubricant sump. The compression mechanism may be disposed in the shell and compressing a working fluid. The crankshaft may be disposed at least partially in the shell and drivingly engaged with the compression mechanism. The bearing support may rotatably support the crankshaft. The lubricant sump may retain a volume of lubricant and disposed between the bearing support and the compression mechanism. 
         [0011]    In yet another form, the present disclosure provides a compressor that may include a unitary body including a shell unitarily formed with a main bearing support. The main bearing support may include a bore for supporting a portion of a crankshaft. The shell may include a continuous annular surface on an interior of the shell adjacent a first end of the shell and a plurality of axially extending arcuate surfaces adjacent a second end of the shell. The plurality of arcuate surfaces being spaced apart along the interior of the shell. 
         [0012]    The compressor may also include a scroll member having a peripheral exterior surface dimensioned to fit inside of the first end of the shell and engage the annular surface. The annular surface may center the scroll member in the shell. 
         [0013]    The compressor may also include a partition plate having a rim dimensioned to fit inside of the first end of the shell and engage the annular surface. The annular surface may center the partition plate relative to the shell. 
         [0014]    The compressor may also include an end cap having a rim dimensioned to fit inside of the second end of the shell and engage the arcuate surfaces. The end cap may have a bore for supporting an end portion of the crankshaft. The arcuate surfaces centering the end cap relative to the shell and axially aligning the bore in the end cap with the bore in the main bearing support. 
         [0015]    The compressor may also include a stator having an exterior surface dimensioned to be received in the shell. The exterior surface may engage the arcuate surfaces. The arcuate surface may center the stator in the shell. 
         [0016]    In yet another form, the present disclosure provides a compressor that may include a shell, a compression mechanism, a crankshaft, a bearing support, and a lubricant sump. The compression mechanism may be disposed in the shell and may compress a working fluid. The crankshaft may be disposed at least partially in the shell and may drivingly engage the compression mechanism. The bearing support may rotatably support the crankshaft. The lubricant sump may retain a volume of lubricant and may be disposed between the bearing support and the compression mechanism. 
         [0017]    In some embodiments, the compressor may include a thrust plate disposed between the bearing support and the compression mechanism. The thrust plate may include an engaging surface that is engaged with the compression mechanism. The lubricant sump may be defined by the thrust plate, the bearing support, and the shell. 
         [0018]    In some embodiments, the bearing support and the thrust plate may both include a plurality of openings allowing the working fluid and the lubricant to flow throughout the shell. 
         [0019]    In some embodiments, the compressor may include a counterweight attached to the crankshaft and rotating with rotation of the crankshaft. The counterweight may travel through lubricant in the lubricant sump during rotation of the crankshaft and may splash the lubricant therein to transmit the lubricant to the compression mechanism. 
         [0020]    In some embodiments, an eccentric portion of the counterweight may travel through lubricant in the lubricant sump during less than one-hundred-eighty degrees of rotation of the crankshaft. 
         [0021]    In some embodiments, the compressor may include an end cap connected to the shell and defining a high-side lubricant sump. 
         [0022]    In some embodiments, the compressor may include a lubricant discharge fitting in fluid communication with the high-side lubricant sump and a heat exchanger. 
         [0023]    In some embodiments, the heat exchanger may include a first fluid passageway receiving lubricant from the high-side lubricant sump and a second fluid passageway receiving a working fluid from the compression mechanism. The first and second fluid passageways may be fluidly isolated from each other. 
         [0024]    In some embodiments, the compression mechanism may include an intermediate-pressure location receiving expanded working fluid from the heat exchanger. 
         [0025]    In some embodiments, the compressor may be in fluid communication with a condenser, an expansion device, and a heat exchanger. The condenser may condense working fluid discharged by the compressor. The expansion device may expand working fluid condensed by the condenser. The heat exchanger may transfer heat from the lubricant to expanded working fluid. 
         [0026]    In some embodiments, the shell may define a first lubricant passageway that is fluidly separated from the lubricant sump and in communication with an inlet of the compressor that is distinct from a working fluid inlet of the compressor. 
         [0027]    In some embodiments, the crankshaft may include a second lubricant passageway providing communication between the lubricant sump and the inlet. 
         [0028]    In another form, the present disclosure provides a compressor that may include a shell, a compression mechanism, a first lubricant sump, and a second lubricant sump. The shell may define a suction-pressure region and a discharge-pressure region. The compression mechanism may be disposed between the suction-pressure region and the discharge-pressure region. The first lubricant sump may be disposed in the suction-pressure region. The second lubricant sump may be disposed in the discharge-pressure region. 
         [0029]    In some embodiments, the compressor may include a crankshaft, a bearing support, and a thrust plate. The crankshaft may drivingly engage the compression mechanism. The bearing support may rotatably supporting the crankshaft. The thrust plate may engage the compression mechanism and may be disposed between the compression mechanism and the bearing support. The first lubricant sump may be defined by the thrust plate, the bearing support, and the shell. The bearing support and the thrust plate may both include a plurality of openings allowing the working fluid and the lubricant to flow throughout the shell. 
         [0030]    In some embodiments, a lubricant level within the first lubricant sumps may be defined by a location of a vertically lowest of one the plurality of openings. 
         [0031]    In some embodiments, the first lubricant sump may be defined by an inner diametrical surface of the shell. 
         [0032]    In some embodiments, the compressor may include a crankshaft, a bearing support, a thrust plate, and a counterweight. The crankshaft may drivingly engage the compression mechanism. The bearing support may rotatably support the crankshaft. The thrust plate may engage the compression mechanism and may be disposed between the compression mechanism and the bearing support. The first lubricant sump may be defined by the thrust plate, the bearing support, and the shell. The counterweight may be attached to the crankshaft and may rotate with the crankshaft. The counterweight may travel through lubricant in the first lubricant sump during rotation of the crankshaft and may splash the lubricant therein to transmit the lubricant to the compression mechanism. 
         [0033]    In some embodiments, an eccentric portion of the counterweight may travel through lubricant in the first lubricant sump during less than one-hundred-eighty degrees of rotation of the crankshaft. 
         [0034]    In some embodiments, the shell may define a lubricant passageway that is separated from the first and second lubricant sumps and in communication with an inlet of the compressor that is distinct from a working fluid inlet of the compressor. 
         [0035]    In some embodiments, the lubricant passageway may extend longitudinally in a direction parallel to a rotational axis of a crankshaft driving the compression mechanism. 
         [0036]    Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood however that the detailed description and specific examples, while indicating preferred embodiments of the invention, are intended for purposes of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0037]    The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
           [0038]      FIGS. 1A-C  are perspective views of a compressor according to the present teachings; 
           [0039]      FIG. 2  is a cross-sectional view along line  2 - 2  of  FIG. 1C ; 
           [0040]      FIGS. 3A and 3B  are perspective views of the shell of the compressor of  FIG. 1 ; 
           [0041]      FIG. 3C  is an end view of the housing of  FIG. 3A ; 
           [0042]      FIG. 4  is an end view of another embodiment of the housing of  FIG. 3C ; 
           [0043]      FIG. 5  is a perspective view of the low-side cover of the compressor of  FIG. 1 ; 
           [0044]      FIG. 6  is a perspective view of the partition of the compressor of  FIG. 1 ; 
           [0045]      FIGS. 7 and 8  are perspective views of the non-orbiting scroll of the compressor of  FIG. 1 ; 
           [0046]      FIG. 9  is a cross-section view along line  9 - 9  of  FIG. 8 ; 
           [0047]      FIG. 10  is an enlarged fragmented cross-sectional view of a portion of the compressor of  FIG. 1  showing features of the non-orbiting scroll and partition; 
           [0048]      FIG. 11  is a cross-sectional view along line  11 - 11  of  FIG. 3A ; 
           [0049]      FIG. 12  is a perspective view of the thrust plate of the compressor of  FIG. 1 ; 
           [0050]      FIG. 13  is a perspective view of another embodiment of the thrust plate of the compressor; 
           [0051]      FIG. 14  is a schematic view of the cooling system utilized with the compressor of  FIG. 1  within a refrigeration system according to the present teachings; and 
           [0052]      FIG. 15  is a schematic view of another cooling system for the lubricant utilized in a compressor and within a refrigeration system according to the present teachings. 
       
    
    
     DETAILED DESCRIPTION 
       [0053]    The following description is merely exemplary in nature and is in no way intended to limit the present disclosure, its application, or uses. 
         [0054]    Referring to  FIGS. 1-3  and  10 , a compressor  20  according to the present teachings is shown. Compressor  20  is a semi-hermetic compressor having a housing or shell  22  with opposite ends  23 ,  25 . A low-side (LS) end cap  24  is attached to end  23  and a partition member  26  and a high-side (HS) end cap  28  are attached to end  25 . LS end cap  24 , partition  26 , and HS end cap  28  can be attached to shell  22  with bolts or other types of fasteners, as known in the art. Other major elements affixed to shell  22  can include a working fluid inlet fitting  30 , a heat exchanger  32 , and an electronics box  31  that can communicate with sensors and other components within or outside compressor  20 . LS end cap  24  includes a lubricant inlet fitting  34 . HS end cap  28  may define a high-side lubricant sump and includes a lubricant outlet fitting  36 . HS end cap  28  can also include a working fluid discharge fitting  38  and a sight gauge  40 . Partition  26  can include a fluid injection inlet fitting  42  that communicates with an intermediate-pressure location in the compression members of the compressor, as described below. HS end cap  28  and partition  26  define a discharge chamber  46 , while LS end cap  24 , shell  22 , and partition  26  define a suction or intake chamber  48 . 
         [0055]    Referring to  FIGS. 2-4  and  11 , shell  22  is a single integral component or piece that can have various features machined therein. By way of non-limiting example, shell  22  can be a cast component. Various features are machined into shell  22  to provide precise alignment for the internal components to be assembled therein. Shell  22  includes a main bearing support  50  with a precision machined central opening  52  therein. Opening  52  is configured to receive a main bearing or bushing  54  to support an intermediate portion of a crankshaft  56 . Bearing  54  can be press fit into opening  52 . 
         [0056]    Main bearing support  50  also includes a plurality of upper peripheral openings  58  that facilitate the flow of the working fluid and lubricant throughout shell  22  and compressor  20 . A lower portion  59  of main bearing support  50  is solid to prevent fluid flow therethrough and defines a portion of an intermediate lubricant sump, as described below. While  FIG. 3C  depicts the main bearing support  50  including three openings  58 , the main bearing support  50  may include four openings  58 , as shown in  FIG. 4 . The four openings  58  shown in  FIG. 4  may be arranged in a pattern that is both vertically and horizontally symmetrical (relative to the view shown in  FIG. 4 ). Such an arrangement of the openings  58  maintains a relatively uniform stiffness across the main bearing support  50 , thereby providing evenly distributed support for the bearing  54  and crankshaft  56 . In still other embodiments not shown in the figures, the main bearing support  50  may include other numbers and arrangements of the openings  58 . For example, three apertures  58 , or any other number of apertures  58 , may be arranged to provide relatively uniform support for the bearing  54  and crankshaft  56 . 
         [0057]    Shell  22  also includes a precision machined surface  60  adjacent end  25 . Surface  60  is cylindrical and acts as the pilot ring for compressor  20 . Surface  60  provides a precision surface for the mounting of a fixed or non-orbiting scroll  62  of a scroll assembly  64 . Surface  60  also provides a precision surface for the mounting of partition  26 . A precision machined shoulder  65  is adjacent surface  60  and provides a precision surface for mounting a thrust plate  112  in shell  22 . Shell  22  also includes a plurality of precision machined surfaces  66  adjacent first end  23 . Each surface  66  forms a part of a cylinder and collectively provide a precision surface for the precise alignment and centering of a stator  68  of a motor  70  within shell  22 . Surfaces  66  also provide a precision surface for the precise alignment and centering of LS end cap  24 . Ends  23 ,  25  are also machined surfaces for the attachment of LS end cap  24  and partition  26  and HS end cap  28  to shell  22 . 
         [0058]    Referring now to  FIGS. 2 and 5 , LS end cap  24  includes a central recessed bore  72  and an outwardly projecting annular rim  74  circumscribing bore  72  and spaced radially inwardly from a periphery  76  of LS end cap  24 . An engaging surface  78  extends between rim  74  and periphery  76 . Engaging surface  78  is configured to engage against end  23  of shell  22 . A gasket or other sealing means can be disposed between surface  78  and end  23  to provide a fluid-tight seal therebetween, by way of non-limiting example. Bore  72  and rim  74  are precision machined surfaces in LS end cap  24  and provide precise centering of LS end cap  24  and crankshaft  56  within compressor  20 . Specifically, a bearing or bushing  82  is press fit into bore  72  and an end  96  of crankshaft  56  is disposed in bearing  82 . Rim  74  engages with multiple surfaces  66  to provide a precise centering of LS end cap  24  relative to shell  22  such that bore  72  is aligned with central opening  52  and crankshaft  56  is precisely located within compressor  20 . 
         [0059]    Motor  70  includes stator  68  and a rotor  84  press fit onto crankshaft  56 . Stator  68  is press fit into shell  22  with the exterior surface of stator  68  engaging with multiple surfaces  66 . As such, surfaces  66  can provide a precise centering of stator  68  within shell  22 . The precision machined surfaces of opening  52 , surfaces  66 , bore  72 , and rim  74  facilitate precise alignment of crankshaft  56  and motor  70  within compressor  20  such that a precise gap exists between rotor  84  and stator  68  along with the proper alignment to the other components of compressor  20 . 
         [0060]    Referring to  FIG. 2 , crankshaft  56  has an eccentric crankpin  86  at one end  88  thereof. Crankpin  86  is rotatably journaled in a generally D-shaped inner bore of a drive bushing  90  disposed in a drive bearing  91  press fit into an orbiting scroll  92  of scroll assembly  64 , as described in more detail below. Drive bushing  90  has a circular outer diameter. An intermediate portion  94  of crankshaft  56  is rotatably journaled in bearing  54  of opening  52  in main bearing support  50 . The other end  96  of crankshaft  56  is rotatably journaled in bearing  82  in bore  72  of LS end cap  24 . 
         [0061]    Crankshaft  56  has, at end  96 , a relatively large diameter, concentric bore  98 , which communicates with a radially outwardly smaller diameter bore  100  extending therefrom to end  88 . Bores  98 ,  100  form an internal lubricant passageway  102  in crankshaft  56 . Lubricant is supplied to bore  98  through a lubricant passageway  104  in LS end cap  24  that communicates with inlet fitting  34 . 
         [0062]    Crankshaft  56  is rotatably driven by electric motor  70  including rotor  84  and stator  68 . A first counterweight  106  is coupled to rotor  84  adjacent end  96  of crankshaft  56 . A second counterweight  108  is attached to crankshaft  56  between end  88  and intermediate portion  94 . 
         [0063]    Referring now to FIGS.  2  and  11 - 12 , a thrust plate  112  is disposed in compressor  20  against machined shoulder  65  between end  25  and main bearing support  50 . Thrust plate  112  may be secured within shell  22  with a plurality of fasteners that engage with complementing bores  116  in shell  22 , by way of non-limiting example. Thrust plate  112  can thereby be fixedly secured within shell  22  with the surface of thrust plate  112  against shoulder  65 . The opposite side of thrust plate  112  includes an annular thrust-bearing surface  114  which axially supports orbiting scroll  92 . Thrust plate  112  includes a central opening  120  and a plurality of upper peripheral openings  122 . Openings  122  are arranged on thrust plate  112  such that thrust plate  112  has a lower solid section  124  below central opening  120 . Solid section  124  defines a portion of an intermediate lubricant sump, as described below. Openings  122  allow fluids, such as lubricant and working fluid, to flow throughout compressor  20 . 
         [0064]    While  FIG. 12  depicts the thrust plate  112  including three openings  122 , the thrust plate  112  having four openings  122 , as shown in  FIG. 13 . The four openings  122  shown in  FIG. 13  may be arranged in a pattern that may provide a relatively uniform stiffness across the thrust plate  112 , thereby providing relatively evenly distributed support for the orbiting scroll  92  and reduces uneven deflection of the thrust plate  112  caused by axial forces exerted on the thrust plate  112  by the orbiting scroll  92 . In still other embodiments not shown in the figures, the thrust plate  112  may include other numbers and arrangements of the openings  122 . For example, three apertures  112  (or any other number of apertures  112 ) may be arranged to provide relatively uniform stiffness across the thrust plate  112  and evenly distributed support for the orbiting scroll  92 . 
         [0065]    Orbiting scroll  92  includes a first spiral wrap  128  on a first surface thereof. The opposite or second surface of orbiting scroll  92  engages with thrust-bearing surface  114  of thrust plate  112  and includes a cylindrical hub  130  that projects therefrom and extends into central opening  120  of thrust plate  112 . Rotatably disposed within hub  130  is bushing  90  in which crankpin  86  is drivingly disposed. Crankpin  86  has a flat on one surface which drivingly engages the flat surface of the inner bore to provide a radially compliant driving arrangement, such as shown in Assignee&#39;s U.S. Pat. No. 4,877,382, the disclosure of which is hereby incorporated by reference. 
         [0066]    An Oldham coupling  136  is disposed between orbiting scroll  92  and thrust plate  112 . Oldham coupling  136  is keyed to orbiting scroll  92  and non-orbiting scroll  62  to prevent rotational movement of orbiting scroll  92 . Oldham coupling  136  is preferably of the type disclosed in Assignee&#39;s U.S. Pat. No. 5,320,506, the disclosure of which is hereby incorporated by reference. A seal assembly  138  is supported by non-orbiting scroll  62  and engages a seat portion  140  of partition  26  for sealingly dividing suction chamber  48  from discharge chamber  46 . Seal assembly  138  can be the same as that disclosed in Assignee&#39;s U.S. patent application Ser. No. 12/207,051, the disclosure of which is incorporated herein by reference. 
         [0067]    Referring now to FIGS.  2  and  7 - 10 , non-orbiting scroll  62  includes a second spiral wrap  142  positioned in meshing engagement with first spiral wrap  128  of orbiting scroll  92 . Non-orbiting scroll  62  has a centrally disposed discharge passage or port  144  defined by a base-plate portion  146 . Non-orbiting scroll  62  also includes an annular hub portion  148 , which surrounds discharge passage  144 . A unitary shutdown device or discharge valve  150  can be provided in discharge passage  144 . Discharge valve  150  is shown as a normally closed valve. During operation of compressor  20 , the valve may be in an open position or a closed position depending on pressure differentials between discharge passage  144  and discharge chamber  46  as well as the design of discharge valve  150 . When operation of compressor  20  ceases, discharge valve  150  closes. 
         [0068]    Non-orbiting scroll  62  includes a machined peripheral surface  154  that is dimensioned for a clearance fit with surface  60  of shell  22 . As a result of the precision machining of surface  60  and peripheral surface  154 , non-orbiting scroll  62  is precisely centered within compressor  20 . Non-orbiting scroll  62  includes an opening  156  adjacent to peripheral surface  154  and extends through base plate portion  146 . Opening  156  is configured to receive an anti-rotation pin  157  which extends from partition  26  to prevent rotation of non-orbiting scroll  62  within compressor  20 . A bleed opening  158  extends through base-plate portion  146  and allows compressed fluid between first and second wraps  128 ,  142  to bleed into an intermediate cavity  160  between non-orbiting scroll  62  and partition  26 . The bleed opening  158  allows pressurized fluid to enter cavity  160  and bias non-orbiting scroll  62  toward orbiting scroll  92 . 
         [0069]    Non-orbiting scroll  62  includes a first radially extending passageway  162  that can receive a temperature probe  164  measuring non-orbiting scroll  62  temperature near the discharge pressure region. By way of non-limiting example, temperature probe  164  could be a positive temperature coefficient thermistor, a negative temperature coefficient thermistor or a thermocouple. Non-orbiting scroll  62  can include a second radial passage  166  that communicates with two branches  168 ,  170 . Passage  166  communicates with inlet fitting  42  that extends through partition  26 . At the end portions of each branch  168 ,  170  are a pair of axially extending openings  172  that extends into the compression cavities formed between first and second wraps  128 ,  142 . Passage  166 , branches  168 ,  170 , and openings  172  allow a fluid to be injected into the compression cavities between first and second wraps  128 ,  142  at intermediate pressure locations. 
         [0070]    Referring now to  FIGS. 2 ,  6 , and  10 , partition  26  includes a machined engaging surface  176  that extends adjacent the periphery and a machined-raised annular rim  178  extending from engaging surface  176 . Engaging surface  176  engages with end  25  of shell  22 . A gasket or other sealing means can be disposed between surface  176  and end  25  to provide a fluid-tight seal therebetween, by way of non-limiting example. Rim  178  engages with precision machined surface  60  of shell  22  to provide precise centering of partition  26  relative to shell  22 . Rim  178  is dimensioned to form a clearance fit against surface  60  of shell  22 . Rim  178  may axially engage with an engaging surface  192  on non-orbiting scroll  62  adjacent its periphery. Engagement of rim  178  with engaging surface  192  limits the axial positioning of non-orbiting scroll  62  within shell  22 . Partition  26  includes a central seat portion  140  that faces non-orbiting scroll  62  and forms a portion of the intermediate cavity  160  that allows pressurized fluid to bias non-orbiting scroll  62  toward orbiting scroll  92 . Partition  26  includes a plurality of openings  182  adjacent the periphery for fastening to shell  22  in conjunction with HS end cap  28  with fasteners. Partition  26  includes an opening  184  in rim  178  that is configured to receive anti-rotation pin  157  that engages with opening  156  in non-orbiting scroll  62  to prevent rotation of non-orbiting scroll  62  within compressor  20 . A pair of radial passages  186 ,  188  is provided in the periphery of partition  26  to receive temperature probe  164  and inlet fitting  42  coupled to an internal fluid injection tube  187 , respectively. Partition  26  includes a second engaging surface  190  on an opposite side from engaging surface  176 . Engaging surface  190  is machined and is configured to engage with a complementary machined engaging surface  194  of HS end cap  28 . A gasket or other sealing means can be disposed between engaging surfaces  190 ,  194  to provide a fluid-tight seal therebetween, by way of non-limiting example. 
         [0071]    Partition  26  includes a central opening  198  that communicates with discharge passage  144  and discharge valve  150  on one side thereof and with a fluid filter/separator  200  on an opposite side thereof. Partition  26  separates the suction chamber  48  from discharge chamber  46 . 
         [0072]    During operation of compressor  20 , working fluid and lubricant flow from suction chamber  48  through lower scroll intake  202  and into the chambers formed between first and second wraps  128 ,  142  and are subsequently discharged through discharge passage  144 , discharge valve  150  and through opening  198  in partition  26  and into separator  200  in discharge chamber  46 . Within separator  200 , the lubricant is separated from the working fluid and the lubricant falls, via gravity, to the lower portion of discharge chamber  46  while the working fluid is discharged from discharge chamber  46  through discharge fitting  38  in HS end cap  28 . 
         [0073]    Referring to  FIGS. 1-2 , outlet fitting  36  in HS end cap  28  communicates with discharge chamber  46  and the lubricant therein. A lubricant line  210  extends from outlet fitting  36  and into a top portion of heat exchanger  32  through a fitting  212 . A lubricant return line  214  extends from a fitting  216  on a lower portion of heat exchanger  32  to inlet fitting  34  on LS end cap  24 . Discharge chamber  46  is at a discharge pressure while suction chamber  48  is at a suction pressure, typically less than the discharge pressure. The pressure differential causes the lubricant to flow from discharge chamber  46  to suction chamber  48  through heat exchanger  32 . Specifically, the lubricant flows through lubricant line  210 , through heat exchanger  32 , through return line  214 , and passageway  104  in LS end cap  24 . From passageway  104 , the lubricant flows into bearing  82  to lubricate bearing  82  along with end  96  of crankshaft  56 . The lubricant also flows into the large bore  98  and then through small bore  100  as it travels to end  88  of crankshaft  56 . When crankshaft  56  is rotating, the centrifugal force causes the lubricant to flow from large bore  98  to small bore  100  and onto end  88 . The lubricant exits end  88  and flows into and around drive bushing  90  in the hub  130  of orbiting scroll  92 . 
         [0074]    The lubricant flowing out of end  88  falls by gravity into an intermediate sump  222 . Intermediate sump  222  is defined by solid section  124  of thrust plate  112  and solid lower portion  59  of main bearing support  50 . Lubricant may accumulate in intermediate sump  222  during operation of compressor  20 . During rotation of crankshaft  56 , counterweight  108  travels through the lubricant in intermediate sump  222  and splashes or sloshes the lubricant therein throughout the space between main bearing support  50  and thrust plate  112  such that Oldham coupling  136  and the interface between thrust plate  112  and orbiting scroll  92  receive lubrication. The lubricant flow provides lubrication and a cooling effect. 
         [0075]    Lubricant within bore  72  of LS end cap  24  can flow downward via gravity and some lubricant may accumulate in a motor area  220  around the lower portion of stator  68  and rotor  84 . Motor area  220  is defined by the opposite side of solid lower portion  59  of main bearing support  50 , shell  22 , and LS end cap  24 . The lubricant exiting bore  72  drops to the bottom of shell  22  and flows to the scroll side of shell  22  through a passageway  226 , as described below. 
         [0076]    Passageway  226  extends between motor area  220  and the far side of thrust plate  112  adjacent lower scroll intake  202 . Passageway  226  can be machined through main bearing support  50  of shell  22 . The separation of passageway  226  from intermediate sump  222  advantageously allows some lubricant to collect or pool in intermediate sump  222  for lubrication of the components therein and adjacent or approximate thereto via the rotation of crankshaft  56  and of counterweight  108 . The engagement of thrust plate  112  with shoulder  65  of shell  22  may provide a semi-fluid-tight engagement wherein lubricant in intermediate sump  222  can pool while still allowing some lubricant to flow out as it is being replaced by incoming lubricant exiting end  88  of crankshaft  56 , thereby providing continuous flow into and out of intermediate sump  222 . The solid section  124  and solid section  59  thereby form an intermediate sump  222  that can pool lubricant therein during operation of compressor  20 . These features may be cast into thrust plate  112  and shell  22 . As shown in  FIG. 2 , the nominal operational lubricant level in intermediate sump  222  is significantly higher than in motor area  220 . The nominal operational lubricant level in discharge chamber  46  is also shown. 
         [0077]    In operation, motor  70  is energized causing crankshaft  56  to begin rotating about its axis, thereby causing orbiting scroll  92  to move relative to non-orbiting scroll  62 . This rotation pulls working fluid into suction chamber  48 . Within suction chamber  48 , working fluid and lubricant mix together and are pulled into lower scroll intake  202  and between first and second wraps  128 ,  142  of orbiting and non-orbiting scrolls  92 ,  62 . The working fluid and lubricant are compressed therein and discharged through discharge passage  144  and discharge valve  150  to discharge pressure. The discharged working fluid and lubricant flow into lubricant separator  200  wherein the working fluid passes therethrough and the lubricant therein is entrapped and flows, via gravity, into the bottom portion of discharge chamber  46 . The working fluid flows out of discharge chamber  46  through discharge fitting  38  and into the system within which compressor  20  is utilized. If the system is a closed system, the working fluid, after passing through the system, flows back into suction chamber  48  of compressor  20  via inlet fitting  30 . 
         [0078]    Referring now to  FIGS. 1 and 14 , cooling of the lubricant when compressor  20  is utilized in conjunction with an exemplary refrigeration system  250  is shown. Refrigeration system  250  includes compressor  20  that compresses the working fluid (e.g., refrigerant) flowing therethrough from a suction pressure to a discharge pressure greater than the suction pressure. Inlet fitting  30  is in fluid communication with a suction line  254  and with suction chamber  48 . Discharge fitting  38  is in fluid communication with a discharge line  256  that receives compressed working fluid from discharge chamber  46  of compressor  20 . Inlet fitting  42  forms an intermediate-pressure port that communicates with the compression cavities of scroll assembly  64  in compressor  20  at a location that corresponds to an intermediate pressure between the discharge pressure and the suction pressure. Inlet fitting  42  can thereby supplies a fluid to the compression cavities of compressor  20  at an intermediate-pressure location. 
         [0079]    Discharge working fluid flowing through discharge line  256  flows into a condenser  258  wherein heat Q 1  is removed from the working fluid flowing therethrough. Heat Q 1  can be discharged to another fluid flowing across condenser  258 . By way of non-limiting example, heat Q 1  can be transferred to an airflow  261  flowing across condenser  258  induced by a fan  260 . Working fluid flowing through condenser  258  can be condensed from a high-temperature, high-pressure vapor-phase working fluid into a reduced-temperature, high-pressure condensed liquid working fluid. 
         [0080]    The condensed working fluid flows from condenser  258  into heat exchanger  32  via a condensed working fluid line  262 . The condensed working fluid can enter a top portion of heat exchanger  32  through a fitting  264 . The working fluid exits heat exchanger  32  through another line  266 . Line  266  can be coupled to a lower portion of heat exchanger  32  and communicate therewith via a fitting  268 . Within heat exchanger  32 , heat Q 2  is removed from the condensed working fluid flowing therethrough, as described below. As a result, the condensed working fluid is sub-cooled and exits heat exchanger  32  at a lower temperature then when entering heat exchanger  32 . 
         [0081]    The sub-cooled condensed working fluid in line  266  flows through a main throttle or expansion device  270 . The working fluid flowing through expansion device  270  expands and a further reduction in temperature occurs along with a reduction in pressure. Expansion device  270  can be dynamically controlled to compensate for a varying load placed on refrigeration system  250 . Alternatively, expansion device  270  can be static. 
         [0082]    The expanded working fluid downstream of expansion device  270  flows through line  272  into an evaporator  274 . Within evaporator  274 , the working fluid absorbs heat Q 3  and may transform from a low-temperature, low-pressure liquid working fluid into an increased-temperature, low-pressure vapor working fluid. The heat Q 3  absorbed by the working fluid can be extracted from an airflow  276  that is induced to flow across evaporator  274  by a fan  278 , by way of non-limiting example. 
         [0083]    Suction line  254  is coupled to evaporator  274  such that working fluid exiting evaporator  274  flows through suction line  254  and back into suction chamber  48  of compressor  20 , thereby forming a closed-system. 
         [0084]    The lubricant from compressor  20  can also flow through heat exchanger  32 , as described above with reference to compressor  20 . Specifically, lubricant can flow, via the pressure difference between discharge chamber  46  and suction chamber  48 , from discharge chamber  46 , through heat exchanger  32 , and back into suction chamber  48 . Within heat exchanger  32 , heat Q 4  can be removed from the lubricant flowing therethrough. As a result, the temperature of the lubricant exiting heat exchanger  32  is less than the temperature of the lubricant entering heat exchanger  32 . 
         [0085]    Compressor  20  and refrigeration system  250  utilize expanded condensed working fluid to absorb heat Q 2  and Q 4  in heat exchanger  32 . Specifically, an economizer circuit can be used to sub-cool the condensed working fluid in heat exchanger  32 . Sub-cooling the condensed working fluid prior to the working fluid flowing through expansion device  270  can increase the capacity of the working fluid to absorb heat Q 3  in evaporator  274  and thereby increase the cooling capacity of refrigeration system  250 . 
         [0086]    To provide the sub-cooling, a portion of the working fluid flowing through line  266  downstream of heat exchanger  32  may be routed through an economizer line  280 , expanded in an economizer expansion device  282  (thereby reducing the temperature and pressure), and directed into heat exchanger  32  through line  284 . Specifically, the economizing working fluid can be routed into a lower portion of heat exchanger  32  through a fitting  286 . The expanded economizing working fluid in line  284  may be in a liquid state, a vapor state, or in a two-phase liquid and vapor state. The economizing working fluid can flow upwardly through heat exchanger  32  and exit into an injection line  288  which is connected to inlet fitting  42  of partition  26 . Specifically, the economizing working fluid can exit an upper portion of heat exchanger  32  through a fitting  290  coupled to injection line  288 . 
         [0087]    Within heat exchanger  32 , the economizing working fluid absorbs heat Q 2  from the condensed working fluid entering heat exchanger  32  through line  262  such that the temperature of the condensed working fluid is reduced (i.e., sub-cooled). The economizing working fluid exiting heat exchanger  32  through injection line  288  is injected into an intermediate-pressure location of scroll assembly  64  through inlet fitting  42  and radial passage  166 , branches  168 ,  170 , and openings  172  in non-orbiting scroll  62 . 
         [0088]    Compressor  20  and refrigeration system  250  advantageously utilize the economizer circuit to cool the lubricant flowing through compressor  20 . Specifically, within heat exchanger  32 , heat Q 4  is transferred from the lubricant into the economizing working fluid. As a result, the temperature of the lubricant exiting heat exchanger  32 , via line  214 , is reduced. Heat exchanger  32  thereby functions as a dual-system heat exchanger. 
         [0089]    Expansion device  282  may be a dynamic device or a static device, as desired, to provide a desired economizer effect and cooling of the lubricant. Expansion device  282  can maintain the pressure in injection line  288  above the pressure at the intermediate-pressure location of the compression cavities that communicate with inlet fitting  42 . The working fluid injected into the intermediate-pressure locations may be in a vapor state, a liquid state, or a two-phase, liquid-vapor state. The injection of the economizing working fluid into an intermediate-pressure location of the scroll assembly  64  may advantageously cool the scrolls and reduce the discharge temperature. 
         [0090]    The use of heat exchanger  32  to extract both heat flows Q 2  and Q 4  can provide a lower complexity and/or less expensive refrigeration system wherein a single heat exchanger can provide both the sub-cooling of the condensed working fluid and the cooling of the lubricant. Additionally, the use of the economizing working fluid to cool the lubricant eliminates the need for a separate or different cooling system for the lubricant along with the use of possibly a different medium to cool the lubricant, such as chilled water. Moreover, the integration of these features into a single heat exchanger  32  allows the heat exchanger to be easily integrated onto compressor  20  such that a more compact design can be achieved, along with reducing the system footprint. 
         [0091]    Optionally, the economizer circuit can utilize condensed refrigerant downstream of condenser  258  and upstream of heat exchanger  32 . Specifically, as shown in phantom in  FIG. 14 , economizer line  280 ′ can extend from line  262  to expansion device  282 . When this is the case, economizer line  280  is not utilized. As a result, a portion of the condensed working fluid flowing through line  262  is routed to expansion device  282  through economizer line  280 ′ and expanded thereacross to form the economizing working fluid flow through heat exchanger  32 . The remaining operation of refrigeration system  250  is the same as that discussed above. 
         [0092]    Referring now to  FIG. 15 , an alternate configuration for cooling the lubricant is schematically illustrated in a refrigeration system  300 . Refrigeration system  300  is similar to refrigeration system  250 , discussed above, and the same reference numerals are utilized to indicate the same or similar components, lines, features, etc. As such, only the main differences between refrigeration system  300  and refrigeration system  250  are discussed in detail. 
         [0093]    A difference in refrigeration system  300  is that a single dual-system heat exchanger  32  is not utilized. Rather, in refrigeration system  300 , two separate heat exchangers  302 ,  304  are utilized. In refrigeration system  300 , heat exchanger  302  functions as an economizer heat exchanger to sub-cool the condensed working fluid flowing therethrough while heat exchanger  304  functions to reduce the temperature of the lubricant flowing therethrough. Specifically, a line  305  extends from expansion device  282  to heat exchanger  302  and directs the expanded working fluid into heat exchanger  302 . Within heat exchanger  302 , heat Q 2  is absorbed by the expanded working fluid from the condensed working fluid entering in heat exchanger  302  through line  262 . As a result, the condensed working fluid is sub-cooled in heat exchanger  302  by the expanded working fluid. 
         [0094]    The expanded working fluid exits heat exchanger  302  through a line  306  and flows into heat exchanger  304 . Heat exchanger  304  operates as a lubricant heat exchanger. Lubricant line  210  extends from compressor  20  into heat exchanger  304  and lubricant return line  214  extends from heat exchanger  304  back to compressor  20 . Within heat exchanger  304 , heat Q 4  is removed from the lubricant flowing therethrough and transferred into the expanded working fluid flowing through heat exchanger  304 . As a result, the temperature of the lubricant flowing through heat exchanger  304  is reduced. 
         [0095]    The expanded working fluid exits heat exchanger  304  and is injected into an intermediate-pressure location within scroll assembly  64  in compressor  20  through injection line  288 , as discussed above. The expanded working fluid flowing through heat exchangers  302 ,  304  can enter therein and exit therefrom in a liquid state, a vapor state, or a two-phase, liquid-vapor state. 
         [0096]    Optionally, in refrigeration system  300 , the sub-cooling of the condensed working fluid can be eliminated. In such an arrangement, heat exchanger  302  and lines  266  and  306  would not be present. Rather, condensed working fluid is extracted from line  262  prior to flowing through expansion device  270 , expanded through expansion device  282 , and provided to heat exchanger  304  through expanded working fluid line  305 ′ (shown in phantom). In this configuration, the working fluid expanded by expansion device  282  is utilized to absorb a single heat flow Q 4  from the lubricant flowing through heat exchanger  304 . As a result, the temperature of lubricant from heat exchanger  304  is reduced. The expanded working fluid exiting heat exchanger  304  is injected into an intermediate-pressure location of compressor  20  through injection line  288 , as discussed above. 
         [0097]    Thus, in refrigeration system  300 , condensed working fluid can be expanded and utilized to sub-cool the condensed working fluid and/or cool the lubricant that flows through compressor  20 . The use of the expanded working fluid can advantageously reduce system complexity and cost by avoiding the necessity of a different external cooling media for cooling the lubricant. Additionally, the use of the expanded working fluid can allow for a space-saving configuration, wherein heat exchanger(s)  302  and/or  304  can be attached to compressor  20 . As a result, a space-saving system can be realized with a reduced system footprint. 
         [0098]    Thus, a compressor and refrigeration system according to the present teachings can advantageously utilize condensed working fluid that is subsequently expanded to reduce the temperature of the lubricant that flows through the compressor. The cooling of the lubricant can be coordinated with an economizer circuit that sub-cools the condensed working fluid. As a result, external cooling media or sources to cool the lubricant are not required. Additionally, a more compact design can be utilized by attaching the one or more heat exchanger(s) to the compressor. In some embodiments, a dual-system heat exchanger can be utilized to both sub-cool the condensed working fluid and cool the lubricant. In other embodiments, separate heat exchangers can be utilized. In some embodiments, expanded working fluid can be utilized without sub-cooling the condensed liquid working fluid line, wherein only the lubricant is cooled with the expanded working fluid. In all of these embodiments, the expanded working fluid that absorbs heat is injected into an intermediate-pressure location of the compressor. The reduction in the temperature of the lubricant can result in a lower injected lubricant temperature, which can reduce suction gas superheat, thereby improving compressor volumetric efficiency and improving performance. Additionally, the reduced lubricant temperature can improve compressor reliability due to the cooling of the suction gas and the motor, and maintain a desirable level of viscosity to achieve proper film thickness between moving parts of the compressor. 
         [0099]    The incorporation of various machined surfaces into the shell of the compressor advantageously facilitates the precise alignment, both centering and axially, of various components within the compressor. The machining of the shell can be accomplished with a single setup thereby providing efficient manufacturing. Additionally, the machined surfaces are all round features that facilitate easy of machining. The components engaging with the machined surfaces of the shell may also be efficiently manufactured. Thus, the compressor may provide superior alignment and/or efficient manufacturing of the compressor. 
         [0100]    The forming of an intermediate sump in the compressor between the main bearing support and the thrust plate can advantageously facilitate the lubricating of the orbiting scroll and related components. The thrust plate, the shell, and the main bearing support can define the intermediate sump. The inclusion of the counter weight on the crankshaft between the main bearing support and the orbiting scroll can advantageously travel through lubricant in the intermediate sump and splash and slosh the lubricant on the components in the area of the intermediate sump. A bypass groove can be machined into the shell to bypass the intermediate sump to allow lubricant to flow from the area of the motor (low side) to the lower scroll intake. 
         [0101]    While the present invention is shown on a horizontal compressor with the motor within the shell, the invention can also be utilized in an open-drive compressor wherein the motor is external to the shell and drives a shaft that extends through the shell. 
         [0102]    The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.