Patent Publication Number: US-2022228590-A1

Title: Compressor Having Seal Assembly

Description:
FIELD 
     The present disclosure relates to a compressor having a seal assembly. 
     BACKGROUND 
     This section provides background information related to the present disclosure and is not necessarily prior art. 
     Heat-pump systems and other working fluid circulation systems include a fluid circuit having an outdoor heat exchanger, an indoor heat exchanger, an expansion device disposed between the indoor and outdoor heat exchangers, and a compressor circulating a working fluid (e.g., refrigerant or carbon dioxide) between the indoor and outdoor heat exchangers. Efficient and reliable operation of the compressor is desirable to ensure that the heat-pump system in which the compressor is installed is capable of effectively and efficiently providing a cooling and/or heating effect on demand. Compressors used in heat-pump systems utilizing low global warming potential (LGWP) refrigerants must operate at higher temperatures than those utilizing conventional refrigerants due to the higher heat of compression of the LGWP refrigerants. These higher temperatures require improvements in the design of the seals used in such compressors to maintain the desired compression ratios and efficiency. 
     SUMMARY 
     This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features. 
     In one form, the present disclosure provides a compressor that includes a shell, a muffler plate, a first scroll member, a second scroll members, and first and second sealing members. The shell defines a first pressure region and a second pressure region. The muffler plate separates the first pressure region and the second pressure region. The first scroll member is disposed within the shell and includes a first end plate and a first scroll wrap. The first end plate defines an annular recess and a discharge recess. The discharge recess is in communication with the first pressure region. The second scroll member includes a second end plate and a second scroll wrap. The second scroll wrap meshingly engaging the first scroll wrap to define a compression chamber therebetween. The first sealing member is at least partially disposed in the discharge recess and fluidly separates the first and second pressure regions from each other. The second sealing member is at least partially disposed in the annular recess. The second sealing member forms a third pressure region that is fluidly isolated from the first and second pressure regions. 
     In some configurations of the compressor of the above paragraph, the second sealing member includes a first end portion sealingly engaged with an inner wall of the annular recess and a second end portion sealingly engaged with an outer wall of the annular recess. 
     In some configurations of the compressor of any one or more of the above paragraphs, the second sealing member includes a planar central portion. The first end portion extends radially inwardly and axially downwardly from the planar central portion and the second end portion extends radially outwardly and axially downwardly from the planar central portion. 
     In some configurations of the compressor of any one or more of the above paragraphs, a spacer is at least partially disposed within the annular recess and includes a first surface contacting the second sealing member and a second surface configured to contact the muffler plate. 
     In some configurations of the compressor of any one or more of the above paragraphs, the second sealing member is U-shaped. 
     In some configurations of the compressor of any one or more of the above paragraphs, the first and second sealing members are made of a flexible material. 
     In some configurations of the compressor of any one or more of the above paragraphs, the first pressure region is a discharge pressure chamber. The second pressure region is a suction pressure chamber and the third pressure region is an intermediate pressure chamber. 
     In some configurations of the compressor of any one or more of the above paragraphs, the muffler plate includes a flange at least partially extending into the discharge recess and partially defining a discharge opening that provides discharge gas from the discharge recess to the first pressure region. 
     In some configurations of the compressor of any one or more of the above paragraphs, a spacer is at least partially disposed within the annular recess and is supported by the second sealing member. The spacer is configured to contact the muffler plate during operation of the compressor. 
     In some configurations of the compressor of any one or more of the above paragraphs, the second sealing member is spaced apart from the muffler plate. 
     In another form, the present disclosure provides a compressor that includes a shell, a muffler plate, a first scroll member, a second scroll member, and first and second sealing members. The shell defines a first pressure region and a second pressure region. The muffler plate separates the first pressure region and the second pressure region. The first scroll member is disposed within the shell and includes a first end plate and a first scroll wrap. The first end plate defines an annular recess and a discharge recess. The discharge recess is in communication with the first pressure region. The second scroll member includes a second end plate and a second scroll wrap. The second scroll wrap meshingly engages the first scroll wrap to define a compression chamber therebetween. The first sealing member is at least partially disposed in the discharge recess and fluidly separates the first and second pressure regions from each other. The second sealing member is at least partially disposed in the annular recess and spaced apart from the muffler plate. The second sealing member forms a third pressure region that is fluidly isolated from the first and second pressure regions. The muffler plate includes a flange at least partially extending into the discharge recess and partially defining a discharge opening that provides discharge gas from the discharge recess to the first pressure region. 
     In some configurations of the compressor of the above paragraph, a biasing member is disposed within the discharge recess and biases the first sealing member toward the flange of the muffler plate. 
     In some configurations of the compressor of any one or more of the above paragraphs, a valve assembly disposed within the discharge recess and including a valve plate and a valve member. The valve plate is coupled to an inside wall of the discharge recess. The valve member is movable between a first position in which fluid in the compression chamber is prevented from flowing to the first pressure region via the valve plate and a second position in which fluid in the compression chamber is allowed to flow to the first pressure region via the valve plate. 
     In some configurations of the compressor of any one or more of the above paragraphs, a biasing member disposed within the discharge recess between the flange and the valve plate. The biasing member biases the first sealing member toward the flange. 
     In some configurations of the compressor of any one or more of the above paragraphs, a pressure relief valve is housed within and extending through an outer wall of the first end plate that defines the annular recess. The pressure relief valve is in fluid communication with the third pressure region to control fluid pressure in the third pressure region. 
     In some configurations of the compressor of any one or more of the above paragraphs, the first sealing member is sealingly engaged with an outer diametrical surface of the flange and an inside wall of the discharge recess. 
     In some configurations of the compressor of any one or more of the above paragraphs, the first sealing member is V-shaped. 
     In some configurations of the compressor of any one or more of the above paragraphs, the first sealing member is sealingly engaged with an inside wall of the discharge recess and an axial end surface of the flange of the muffler plate. 
     In some configurations of the compressor of any one or more of the above paragraphs, the first sealing member is made of a flexible material. 
     In some configurations of the compressor of any one or more of the above paragraphs, the first sealing member includes an end portion that at least partially extends into the discharge opening of the muffler plate. The first sealing member is moveable downwardly when the compressor is in a shutdown state to allow discharge gas in the first pressure region to flow toward the second pressure region. 
     In some configurations of the compressor of any one or more of the above paragraphs, a spacer is at least partially disposed within the annular recess and supported by the second sealing member. The spacer includes radially extending grooves that allow discharge gas in the first pressure region to flow toward the second pressure region when the compressor is in the shutdown state. 
     In some configurations of the compressor of any one or more of the above paragraphs, a biasing member is disposed within the discharge recess and biases the first sealing member toward the flange of the muffler plate. Discharge fluid in the first pressure region overcomes the biasing force of the biasing member when the compressor is in the shutdown state to allow discharge gas in the first pressure region to flow toward the second pressure region. 
     Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
    
    
     
       DRAWINGS 
       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. 
         FIG. 1  is a cross-sectional view of a compressor including a seal assembly in accordance with the principles of the present disclosure; 
         FIG. 2  is a close-up view of the compressor indicated as area  2  in  FIG. 1 ; 
         FIG. 3  is an exploded view of a compression mechanism of the compressor and the seal assembly; 
         FIG. 4  is a partial cross-sectional view of the compressor in a shutdown state; 
         FIG. 5  is a cross-sectional view of another compression mechanism and seal assembly; 
         FIG. 6  is a cross-sectional view of another seal assembly; and 
         FIG. 7  is a cross-sectional view of another seal assembly. 
     
    
    
     Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION 
     Example embodiments will now be described more fully with reference to the accompanying drawings. 
     Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail. 
     The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed. 
     When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
     Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments. 
     Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated  90  degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. 
     As shown in  FIG. 1 , a compressor  10  is provided that may include a hermetic shell assembly  12 , a first bearing housing assembly  14 , a second bearing housing assembly  16 , a motor assembly  18 , a compression mechanism  20 , transversely extending partition or muffler plate  21 , and a seal assembly  22 . 
     The shell assembly  12  may form a compressor housing and may include a cylindrical shell  26 , an end cap  28  at an upper end thereof, and a base  30  at a lower end thereof. The end cap  28  and the partition  21  may define a discharge chamber  32 . The partition  21  may separate the discharge chamber  32  from a suction chamber  33 . A discharge fitting (not shown) may be attached to the shell assembly  12  at an opening in the end cap  28 . A discharge valve assembly (not shown) may be disposed within the discharge fitting and may generally prevent a reverse flow condition. A suction inlet fitting  39  may be attached to shell assembly  12  at an opening  45 . 
     The first bearing housing assembly  14  may be fixed relative to the shell  26  and may include a main bearing housing  40  and a first bearing  42 . The main bearing housing  40  may house the first bearing  42  therein and may define an annular flat thrust bearing surface  48  on an axial end surface thereof. 
     The motor assembly  18  may include a motor stator  52 , a rotor  54 , and a drive shaft  56 . The motor stator  52  may be press fit into the shell  26 . The rotor  54  may be press fit on the drive shaft  56  and may transmit rotational power to the drive shaft  56 . The drive shaft  56  may be rotatably supported within the first and second bearing housing assemblies  14 ,  16 . The drive shaft  56  may include an eccentric crank pin  58  having a flat thereon. 
     The compression mechanism  20  may include an orbiting scroll  62  and a non-orbiting scroll  64 . The orbiting scroll  62  may include an end plate  66  having a spiral wrap  68  on an upper surface thereof and an annular flat thrust surface  70  on a lower surface. The thrust surface  70  may interface with the annular flat thrust bearing surface  48  on the main bearing housing  40 . A cylindrical hub  72  may project downwardly from thrust surface  70  and may include a drive bushing  74  and an unloader bushing  77  disposed therein. The unloader bushing  77  may include an inner bore in which the crank pin  58  is drivingly disposed. The crank pin flat may drivingly engage a flat surface in a portion of the inner bore to provide a radially compliant driving arrangement. An Oldham coupling  76  may be engaged with the orbiting and non-orbiting scrolls  62 ,  64  to prevent relative rotation therebetween. 
     With reference to  FIGS. 1-4 , the non-orbiting scroll  64  may include an end plate  78  and a spiral wrap  80  projecting downwardly from the end plate  78 . The spiral wrap  80  may meshingly engage the spiral wrap  68  of the orbiting scroll  62 , thereby creating a series of moving fluid pockets. The fluid pockets defined by the spiral wraps  68 ,  80  may decrease in volume as they move from a radially outer position (at a suction pressure) to a radially intermediate position (at an intermediate pressure) to a radially inner position (at a discharge pressure) throughout a compression cycle of the compression mechanism  20 . 
     As shown in  FIGS. 1-4 , the end plate  78  may include a discharge passage  82 , a discharge recess  84 , and an annular recess  88 . The discharge passage  82  is in communication with one of the fluid pockets at the radially inner position and allows compressed working fluid (at the discharge pressure) to flow through the discharge recess  84  and into the discharge chamber  32 . The annular recess  88  may encircle the discharge recess  84  and may be substantially concentric therewith. The annular recess  88  may include an inner surface  89  and an outer surface  90 . 
     As shown in  FIG. 3 , the partition  21  may include a lobe  94 , a wedge  96  and a hub  98 . The lobe  94  may extend from the wedge  96  and the hub  98 , and may include opposing outer walls  99   a,    99   b,  an arcuate back wall  100  and a planar upper wall  102 . One or more safety devices (e.g., thermally operated valve) may be placed on the planar upper wall  102  of the lobe  94 , and may facilitate venting of the discharge chamber  32  when fluid temperatures therein exceed a predetermined threshold, for example. 
     The wedge  96  may extend from and substantially around the hub  98  and may include a body portion  106  and an end portion  108 . The body portion  106  extends downwardly at an angle from the hub  98  to the end portion  108 . The end portion  108  extends downwardly from an end of the body portion  106 . As shown in  FIGS. 1, 2 and 4 , the hub  98  may include a circumferentially-shaped flange or lip  110  that extends downwardly in an axial direction into the discharge recess  84  and may at least partially define a discharge passage  111  in the partition  21 . In this way, the discharge passage  111  provides fluid communication between the compression mechanism  20  and the discharge chamber  32 . 
     As shown in  FIGS. 1-4 , a shutdown device  112  may be disposed within the discharge recess  84  and may include a housing  114  and a valve  118 . The housing  114  may rest on a lower surface  120  of the discharge recess  84  and may be engaged to an outer diametrical wall  123  of the discharge recess  84 . The valve  118  may be disposed between the housing  114  and the discharge passage  82  and may be moveable between a first position ( FIG. 4 ; closed position) in which fluid in the compression pockets is prevented from flowing from the discharge passage  82  to the discharge chamber  32 , and a second position ( FIGS. 1 and 2 ; open position) in which fluid in the compression pockets is allowed to flow from the discharge passage  82  to the discharge chamber  32 . The valve  118  abuts against a bottom surface  125  of the discharge recess  84  when in the first position and abuts against the housing  114  when in the second position. When the valve  118  is in the second position, compressed working fluid flows around the valve  118 , through openings  127  extending through the housing  114  and into the discharge chamber  32 . 
     The seal assembly  22  may include a first annular sealing member  128 , a biasing member  129 , a second annular sealing member  130  and an annular spacer  132 . During operation of the compressor  10 , the first annular sealing member  128  may be sealingly engaged with an inner diametrical surface  134  of the discharge recess  84  and the flange  110  of the muffler plate  21  to prevent fluid discharged from the compression mechanism  20  from flowing to the suction chamber  33  ( FIGS. 1 and 2 ). The first annular sealing member  128  may be made of a flexible material and may be positioned between the flange  110  of the muffler plate  21  and the shutdown device  112 . 
     The first annular sealing member  128  may include a planar first portion  133  and a second portion  135 . The first portion  133  may have an upper surface  136  sealingly engaged with an axial end surface  137  of the flange  110 . The second portion  135  may extend generally radially outwardly and axially downwardly from the first portion  133 , and may be sealingly engaged with the inner diametrical surface  134  of the discharge recess  84 . In this way, fluid in the discharge chamber  32  and fluid discharged from the compression mechanism  20  are restricted from flowing to the suction chamber  33 . 
     The biasing member  129  (e.g., a coiled spring) may be positioned between the housing  114  and the flange  110  and may bias the first annular sealing member  128  toward the flange  110 . A first end  143  of the biasing member  129  may be coupled to the housing  114  and a second end  145  of the biasing member  129  may be coupled to the first portion  133  of the first annular sealing member  128 . In this way, the biasing member  129  may bias the sealing member  128  such that it is sealingly engaged with the flange  110  of the muffler plate  21 . 
     The second annular sealing member  130  may be disposed within the annular recess  88  and may cooperate with the annular recess  88  to define an intermediate-pressure chamber  138 . The intermediate-pressure chamber  138  receives fluid from the fluid pocket in the intermediate position through an intermediate passage (not shown) formed in the end plate  78 . A pressure differential between the intermediate-pressure fluid in the intermediate-pressure chamber  138  and fluid in the suction chamber  33  exerts a net axial biasing force on the non-orbiting scroll  64  urging the non-orbiting scroll  64  toward the orbiting scroll  62 . In this manner, the tips of the spiral wrap  80  of the non-orbiting scroll  64  are urged into sealing engagement with the end plate  66  of the orbiting scroll  62  and the end plate  78  of the non-orbiting scroll  64  is urged into sealing engagement with the tips of the spiral wrap  68  of the orbiting scroll  62 . A gap may be formed between the non-orbiting scroll  64  and the muffler plate  21  ( FIGS. 1, 2, and 4 ). 
     The second annular sealing member  130  may be spaced apart from the muffler plate  21  (i.e., does not contact the muffler plate  21 ) and may include a planar portion  139 , a first end portion  140 , and a second end portion  141 . The first end portion  140  may extend generally radially outwardly and axially downwardly from the planar portion  139  and may be sealingly engaged with the outer surface  90  of the annular recess  88 . The second end portion  141  may extend generally radially inwardly and axially downwardly from the planar portion  139  and may be sealingly engaged with the inner surface  89  of the annular recess  88 . In this way, fluid in the intermediate-pressure chamber  138  is prevented from flowing to the suction chamber  33 . 
     The spacer  132  may be at least partially disposed within the annular recess  88  and may be supported by the second annular sealing member  130 . The spacer  132  includes a first or lower surface  146  and a second or upper surface  148 . The first surface  146  contacts the planar portion  139  of the second annular sealing member  130  and the second surface  148  is configured to abut against a lower surface  150  of the hub  98  of the muffler plate  21 . A plurality of radially extending grooves  152  may be formed in and around the second surface  148  of the spacer  132  ( FIG. 3 ). In this way, when the compressor  10  is in a shutdown state, the first annular sealing member  128  may move downwardly in the discharge recess  84 , which allows discharge gas in the discharge chamber  32  to flow toward the suction chamber  33  ( FIG. 4 ; discharge gas in the discharge chamber  32  is allowed to flow through a gap  154  between the sealing member  128  and the flange  110 , through the grooves  152  in the spacer  132  and out into the suction chamber  33 ). 
     With reference to  FIG. 5 , another compression mechanism  220  and seal assembly  222  are provided. The compressor mechanism  220  and the seal assembly  222  may be incorporated into the compressor  10  instead of compression mechanism  20  and seal assembly  22 , respectively. The structure and function of the compression mechanism  220  and seal assembly  222  may be similar or identical to the compression mechanism  20  and seal assembly  22 , respectively, described above, apart from any exception noted below. 
     The compression mechanism  220  may include an orbiting scroll  262  and a non-orbiting scroll  264 . The orbiting scroll  262  may be similar or identical to the orbiting scroll  62 , described above, and therefore, will not be described again in detail. The non-orbiting scroll  264  may include an end plate  278  and a spiral wrap  280  projecting downwardly from the end plate  278 . The spiral wrap  280  may meshingly engage spiral wrap  268  of the orbiting scroll  262 , thereby creating a series of moving fluid pockets. 
     The end plate  278  may include a discharge passage  282 , a discharge recess  284 , and an annular recess  288 . The discharge passage  282  is in communication with one of the fluid pockets at the radially inner position and allows compressed working fluid (at the discharge pressure) to flow through the discharge recess  284  and into the discharge chamber. A pressure relief valve  250  may be housed within and may extend through an outer wall  252  of the end plate  278  that defines the annular recess  288 . In this way, the pressure relief valve  250  is in fluid communication with the suction chamber and an intermediate-pressure chamber  238  and may control fluid pressure in the intermediate-pressure chamber  238 . 
     A shutdown device  212  may be disposed within the discharge recess  284  and may include a housing  214  and a valve  218 . The housing  214  may rest on a lower surface  221  of the discharge recess  284  and may be engaged to an outer diametrical wall  223  of the discharge recess  284  (e.g., threadably engaged to the outer diametrical wall  223 ). The valve  218  may be disposed between the housing  214  and the discharge passage  282  and may be moveable between a first position (i.e., closed position) in which fluid in the compression pockets is prevented from flowing from the discharge passage  282  to the discharge chamber  32 , and a second position (i.e., open position) in which fluid in the compression pockets is allowed to flow from the discharge passage  282  to the discharge chamber  32 . The valve  218  abuts against a bottom surface  225  of the discharge recess  284  when in the first position and abuts against the housing  214  when in the second position ( FIG. 5 ). When the valve  218  is in the second position, compressed working fluid flows around the valve  218 , through openings  227  extending through the housing  214  and into the discharge chamber  32 . 
     The seal assembly  222  may include a first annular sealing member  228 , a second annular sealing member  230  and an annular spacer  232 . The first annular sealing member  228  may be disposed within the discharge recess  284  of the end plate  78  of the non-orbiting scroll  64 , and may be sealingly engaged with an inner diametrical surface  234  of the discharge recess  284  and the flange  110  of the muffler plate  21  to prevent fluid discharged from the compression mechanism  220  from flowing to the suction chamber. 
     The first annular sealing member  228  may be V-shaped or U-shaped and may include a first end portion  236  and a second end portion  237 . The first end portion  236  may be sealingly engaged with the inner diametrical surface  234  of the discharge recess  284 . The second end portion  237  may be sealingly engaged with an outer diametrical surface  239  of the flange  110  of the muffler plate  21 . 
     The second annular sealing member  230  may be similar or identical to the sealing member  130  described above, and therefore, will not be described again in detail. The spacer  232  may be similar or identical to the spacer  132  described above, and therefore, will not be described again in detail. 
     With reference to  FIG. 6 , another seal assembly  322  is provided. The seal assembly  322  may be incorporated into the compressor  10  instead of seal assemblies  22 ,  222 . The structure and function of the seal assembly  322  may be similar or identical to seal assemblies  22 ,  222  described above, apart from any exception noted below. 
     A shutdown device  312  may be disposed within the discharge recess  84 . The shutdown device  312  may be similar or identical to the shutdown devices  112 ,  212 , described above, and therefore, will not be described again in detail. 
     The seal assembly  322  may include a first annular sealing member  328 , a biasing member  329 , a second annular sealing member  330  and an annular spacer  332 . The first annular sealing member  328  may be disposed within the discharge recess  84  of the end plate  78  of the non-orbiting scroll  64 , and may be sealingly engaged with the inner diametrical surface  134  of the discharge recess  84  and the flange  110  of the muffler plate  21  to prevent fluid discharged from the compression mechanism  20  from flowing to the suction chamber. 
     The first annular sealing member  328  may include a planar portion  333 , a first end portion  334  and a second end portion  335 . The planar portion  333  may have an upper surface  336  sealingly engaged with the axial end surface  137  of the flange  110 . The first end portion  334  may extend generally radially outwardly and axially downwardly from the planar portion  333  and may be sealingly engaged with the inner diametrical surface  134  of the discharge recess  84 . The second end portion  335  may extend generally radially inwardly and axially upwardly from the planar portion  333  and may be at least partially received in the discharge passage  111  of the muffler plate  21 . The second end portion  335  may also be spaced apart from the flange  110  of the muffler plate  21 . When the compressor  10  in the shutdown state, discharged fluid in the discharge chamber  32  may flow to a gap  350  between the flange  110  and the second end portion  335 , and may overcome the force of the biasing member  329  to push the first annular sealing member  328  downward. In this way, the discharged fluid may flow through a gap (not shown) between the flange  110  and the planar portion  333  of the sealing member  328  and out into the suction chamber  33 . The biasing member  329  (e.g., a coiled spring) may be positioned between a housing  314  of the device  312  and the flange  110  and may bias the first annular sealing member  328  toward the flange  110 . 
     The second annular sealing member  330  may be similar or identical to the sealing members  130 ,  230 , described above, and therefore, will not be described again in detail. The spacer  332  may be similar or identical to the spacers  132 ,  232 , described above, and therefore, will not be described again in detail. 
     With reference to  FIG. 7 , another seal assembly  422  is provided. The seal assembly  422  may be incorporated into the compressor  10  instead of seal assemblies  22 ,  222 ,  322 . The structure and function of the seal assembly  422  may be similar or identical to seal assemblies  22 ,  222 ,  322  described above, apart from any exception noted below. 
     A shutdown device  412  may be disposed within the discharge recess  84 . A shutdown device  412  may be disposed within the discharge recess  84  and may include a housing  414 , a biasing member  416  and a valve  418 . The housing  414  may rest on a lower surface  420  of the discharge recess  84 . The biasing member  416  (e.g., a wavy spring) may be received in a groove  422  formed in an inner diametrical surface  424  of the discharge recess  84  and may bias the housing  414  against the lower surface  420  of the discharge recess  84 . In this way, the housing  414  is prevented from vibrating during operation of the compressor  10 . The valve  418  is moveable between a first position (i.e., closed position) in which fluid in the compression pockets is prevented from flowing from the discharge passage  82  to the discharge chamber, and a second position (i.e., open position) in which fluid in the compression pockets is allowed to flow from the discharge passage  82  to the discharge chamber. 
     The seal assembly  422  may include a first annular sealing member  428 , a second annular sealing member  430  and an annular spacer  432 . The first sealing member  428  may be similar or identical to the sealing member  130  described above, and therefore, will not be described again in detail. The second sealing member  430  may be similar or identical to the sealing members  130 ,  230 ,  330  described above, and therefore, will not be described again in detail. The spacer  432  may be similar or identical to the spacers  132 ,  232 ,  332  described above, and therefore, will not be described again in detail. 
     The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.