Patent Publication Number: US-2006018778-A1

Title: Hermetic compressor

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
      This application claims the benefit of Korean Patent Application No. 2004-56456, filed on Jul. 20, 2004 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a hermetic compressor, and, more particularly, to a hermetic compressor having a discharge muffler capable of attenuating noise generated when a compressed refrigerant is discharged to the outside.  
      2. Description of the Related Art  
      In general, a hermetic compressor is designed to suction a refrigerant into a hermetic casing thereof to compress it, and discharge the compressed refrigerant to the outside. Such a hermetic compressor comprises a compressing unit to compress the refrigerant and a driving unit to drive the compressing unit.  
      The compressing unit is disposed inside the hermetic casing, and includes a cylinder block defining a compression chamber, and a piston reciprocating inside the compression chamber upon receiving power transmitted from the driving unit. A cylinder head is disposed at one side of the cylinder block and is formed with a suction chamber and a discharge chamber, which communicate with the outside.  
      A valve unit is provided between the cylinder block and the cylinder head in order to permit selective communication between the suction chamber and the compression chamber or between the discharge chamber and the compression chamber.  
      In order to attenuate noise of the refrigerant discharged from the discharge chamber, a pair of discharge mufflers are provided at both ends of the cylinder block, respectively. A respective one of the discharge mufflers has a muffler body defined in the cylinder block, and a muffler cover to cover the muffler body. A baffle is mounted in the discharge muffler in order to attenuate vortex motion or pulsation of the refrigerant.  
      However, the conventional hermetic compressor configured as stated above has a problem in that the baffle must be present inside the discharge muffler, resulting in a complicated manufacturing process and high manufacturing cost.  
      Further, when the baffle is displaced out of its original installation position due to the pressure of the refrigerant, this hinders proper discharge of the refrigerant.  
     SUMMARY OF THE INVENTION  
      The present invention has been made in view of the above mentioned problems, and an aspect of the invention is to provide a hermetic compressor having a discharge muffler which is improved in structure to achieve enhanced productivity and reliability.  
      In accordance with an aspect, the present invention provides a hermetic compressor comprising a cylinder block defining a compression chamber, a piston reciprocating inside the compression chamber to compress a refrigerant, and a discharge muffler configured to receive the refrigerant compressed in the compression chamber, wherein the discharge muffler includes a muffler body defined in the cylinder block and a muffler cover to cover the muffler body, and wherein the muffler body has an integral partition to divide the interior of the discharge muffler into a pair of resonance chambers communicating with each other.  
      The partition may be integrally formed with the muffler body by casting.  
      The partition may protrude from a bottom surface of the muffler body toward the muffler cover so that it is spaced apart from the muffler cover by a predetermined distance.  
      The partition may be inwardly spaced apart from an inner circumference of the muffler body by a predetermined distance.  
      One of the resonance chambers may be provided with an inlet to permit the resonance chamber to communicate with the compression chamber, and a discharge tube may be located in the other resonance chamber in order to discharge the refrigerant in the interior of the discharge muffler to the outside.  
      The muffler cover may be coupled to the muffler body via a bolt, and the partition has a screw bore to permit the bolt to be fastened therethrough.  
      An auxiliary muffler may be provided in the cylinder block to communicate with the discharge muffler via an auxiliary channel defined in the cylinder block.  
      Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      These and/or other aspects and advantages of the invention will become apparent and more easily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:  
       FIG. 1  is a side sectional view illustrating a hermetic compressor in accordance with the present invention;  
       FIG. 2  is a plan view illustrating a discharge muffler provided in the hermetic compressor in accordance with a first embodiment of the present invention;  
       FIG. 3  is a sectional view of the discharge muffler shown in  FIG. 2 ;  
       FIG. 4  is a cross sectional view taken along line A-A shown in  FIG. 3 ;  
       FIG. 5  is a sectional view of a discharge muffler in accordance with a second embodiment of the present invention;  
       FIG. 6  is a cross sectional view taken along line B-B shown in  FIG. 5 ; and  
       FIG. 7  is a sectional view illustrating an auxiliary muffler provided in a cylinder block in addition to the discharge muffler in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout.  
       FIG. 1  is a side sectional view of a hermetic compressor in accordance with the present invention. Referring to  FIG. 1 , the hermetic compressor of the present invention comprises a compressing unit  20  disposed inside a hermetic casing  10  to compress a refrigerant, and a driving unit  30  to generate power required to drive the compressing unit  20 .  
      The compressing unit  20  includes a cylinder block  21  internally defining a compression chamber  21   a , and a piston  22  reciprocating inside the compression chamber  21   a  so as to suction, compress and discharge the refrigerant. A cylinder head  23  is disposed at one end of the cylinder block  21  to face each other. The cylinder head  23  internally defines a suction chamber  23   a  and a discharge chamber  23   b . A valve unit  24  is interposed between the cylinder block  21  and the cylinder head  23  so as to selectively communicate the suction chamber  23   a  or the discharge chamber  23   b  with the compression chamber  21   a.    
      The driving unit  30  operates to reciprocate the piston  22 , thereby permitting the refrigerant to be compressed inside the compressing unit  20 . The driving unit  30  includes a stator  31  fixedly disposed inside the hermetic casing  10 , and a rotor  32  inwardly spaced apart from the stator  31  to electromagnetically interact with the stator  31 . A rotating shaft  33  is coupled in the center of the rotor  32  to rotate simultaneously with the rotor  32 . An end of the rotating shaft  33  is coupled to one end of a connecting rod  34  to permit rotation of the connecting rod  34 . The rotation of the connecting rod  34  causes the other end thereof to linearly reciprocate to thereby move the piston  22  forward or backward.  
       FIG. 2  is a plan view illustrating a discharge muffler provided in the hermetic compressor in accordance with a first embodiment of the present invention. Referring to  FIG. 2 , the discharge muffler  40  according to the first embodiment of the present invention is provided at at least one of both ends of the cylinder block  21  and is adapted to attenuate noise of the refrigerant being discharged out of the compressor. The discharge muffler  40  has a dented muffler body  50  defined in the cylinder block  21  and a muffler cover  60  to cover the muffler body  50 .  
      The muffler body  50  has an inlet  51  to permit introduction of the refrigerant into the discharge muffler  40 . The inlet  51  communicates with a guide channel  25  which is perforated through the cylinder block  21  to guide the refrigerant from the compression chamber  21   a  into the discharge muffler  40 .  
       FIG. 3  is a sectional view of the discharge muffler  40  shown in  FIG. 2 .  FIG. 4  is a cross sectional view taken along line A-A shown in  FIG. 3 . Referring to  FIGS. 3 and 4 , a seating groove  52  is defined at an upper en of the muffler body  50  for the seating of the muffler cover  60 . When the muffler cover  60  covers the muffler body  50 , it defines a space to attenuate pulsation of the refrigerant. A discharge tube  70  is mounted in the muffler cover  60  to communicate with the interior of the discharge muffler  40 . The discharge tube  70  serves to discharge the refrigerant out of the compressor.  
      The muffler body  50  has a partition  53  to divide the interior of the discharge muffler  40  into first and second resonance chambers S 1  and S 2 . The partition  53  is integrally formed with the muffler body  50  upon casting of the cylinder block  21 .  
      The partition  53  protrudes from a bottom surface of the muffler body  50  toward the muffler cover  60  so that a distal end thereof is spaced apart from the muffler cover  60  to define a first communicating portion S 3  between the partition  53  and the muffler cover  60 . That is, the interior of the discharge muffler  40  is divided into the first and second resonance chambers S 1  and S 2  by the partition  53 , and both the first and second resonance chambers S 1  and S 2  communicate with each other via the first communicating portion S 3 .  
      In this case, the inlet  51  is formed at the first resonance chamber S 1 , and the discharge tube  70  is positioned in the second resonance chamber S 2 . With such a configuration, the refrigerant, introduced into the first resonance chamber S 1 , is compressed while passing through the first communicating portion S 3 , and is diffused in the second resonance chamber S 2 , thereby being attenuated in pulsation thereof.  
      Meanwhile, the muffler cover  60  is coupled to the muffler body  50  by means of a bolt  80 . The bolt  80  is fastened into a screw bore  54  defined in the partition  53  of the muffler body  50 .  
       FIG. 5  is a sectional view of a discharge muffler in accordance with a second embodiment of the present invention.  FIG. 6  is a cross sectional view taken along line B-B shown in  FIG. 5 . The second embodiment is identical to the first embodiment except for a partition  53 ′.  
      Referring to  FIGS. 5 and 6 , the partition  53 ′ is formed at the muffler body  50  so that it is inwardly spaced apart from the muffler body  50 . Thereby, in addition to the first communicating portion S 3  defined between the partition  53 ′ and the muffler cover  60 , the discharge muffler according to the present embodiment further includes a second communicating portion S 4  defined between opposite ends of the partition  53 ′ and an inner circumference of the muffler body  50 .  
      With such a configuration, the refrigerant flows from the first resonance chamber S 1  into the second resonance chamber S 2  via both the first communicating portion S 3  and the second communicating portion S 4 .  
      It will be easily understood that the configuration of the partition provided in the discharge muffler of the present invention is not limited to that of the above described partitions  53  and  53 ′, and may have various different configurations depending on the characteristics of the compressors.  
      Meanwhile, as shown in  FIG. 7 , an auxiliary muffler  90  may be provided in the cylinder block  21  in addition to the discharge muffler  40 . The auxiliary muffler  90  communicates with the discharge muffler  40  via an auxiliary channel  91  defined in the cylinder block  21 . Such an auxiliary muffler  90  more attenuates the pulsation noise of the refrigerant via a Helmholtz resonance chamber defined therein.  
      Now, the general operation of the hermetic compressor according to the present invention will be explained.  
      When power is applied to the driving unit  30 , the rotor  32  rotates simultaneously with the rotating shaft  33 . The rotation of the rotating shaft  33  causes the piston  22  to reciprocate inside the compression chamber  21   a  to thereby allow the refrigerant to be suctioned from the suction chamber  23   a  of the cylinder head  23  into the compression chamber  21   a  and be compressed in the compression chamber  21   a . After that, the compressed refrigerant is discharged into the discharge chamber  23   b  of the cylinder head  23  via the valve unit  24  according to reciprocation of the piston  22 .  
      After that, the refrigerant discharged into the discharge chamber  23   b  is guided toward the discharge muffler via the guide channel  25  defined in the cylinder block  21 . Thereby, the refrigerant, introduced into the discharge muffler via the inlet  51  of the muffler body  50 , is attenuated in noise in the first resonance chamber S 1 . In succession, the refrigerant is compressed while passing through the partition  53 , and is diffused in the second resonance chamber S 2 . In this way, the pulsation of the refrigerant is attenuated. Finally, the refrigerant is discharged out of the compressor via the discharge tube  70  located in the second resonance chamber S 2 .  
      As is apparent from the above description, the present invention provides a hermetic compressor having a discharge muffler in which a partition is integrally formed with a muffler body defined in a cylinder block.  
      Such a configuration permits a refrigerant, introduced into the discharge muffler, to undergo attenuation of pulsation thereof while passing through the partition, enabling effective attenuation of noise of the refrigerant being discharged out of the compressor.  
      Further, according to the present invention, the partition is integrally formed with the muffler body upon casting of the discharge muffler. This simplifies the manufacturing process of the discharge muffler, reducing the manufacturing cost thereof.  
      Although an embodiment of the present invention has been shown and described, it would be appreciated by those skilled in the art that changes may be made in this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.