Abstract:
In a valve assembly of a reciprocating compressor including a piston having a valve seat portion ( 26 ) at the front and plural suction ( 24 ) holes for sucking a fluid at regular intervals in the circumferential direction; and a suction valve ( 20 ) arranged on the valve seat portion ( 26 ) to perform opening/closing operation of the suction holes ( 24 ), wherein the suction valve ( 20 ) includes a fixed portion fixed to the valve seat portion ( 26 ) of the piston; an open/close portion formed at the outside of the fixed portion to perform opening/closing operation of the suction holes ( 24 ); and plural neck ( 32 ) portions formed between the fixed portion ( 28 ) and the open/close portion ( 30 ) at regular intervals. Accordingly, by minimizing fatigue occurrence according to continued opening/closing operation by reducing an opening angle of the valve, damage or breakage of the valve can be minimized.

Description:
TECHNICAL FIELD  
       [0001]     The present invention relates to a valve assembly, and in particular to a valve assembly of a reciprocating compressor capable of preventing damage of a valve due to compressive pressure and improving productivity.  
       BACKGROUND ART  
       [0002]     Generally, various types of compressors can be applied according to compression methods, and a hermetic compressor is mainly used for an air conditioner required to be small-sized and light-weighted. The hermetic compressor can be divided into a rotary compressor, a reciprocating compressor and a scroll compressor, etc. according to fluid compressing methods.  
         [0003]     In the reciprocating compressor, a fluid is compressed while a piston of a compressing unit performs a linear reciprocating motion inside a cylinder by a driving force generated in a driving unit. 
        a valve assembly of the reciprocating compressor is installed between a compression chamber in which a fluid is compressed and a suction passage in which the fluid is sucked. When the fluid is sucked, the valve assembly is open by pressure of the fluid and supplies the fluid through the suction passage into the compression chamber. And, when the fluid is compressed, the valve assembly prevents the fluid compressed in the compression chamber from flowing backward.        
 
         [0005]      FIG. 1  is a partial-sectional view illustrating a valve assembly of a reciprocating compressor in accordance with the conventional art, and  FIG. 2  is an exploded-perspective view illustrating the conventional valve assembly.  
         [0006]     A compressing unit of a reciprocating compressor in accordance with the conventional art includes a cylinder  104  is fixed to a casing (not shown) and having a compression chamber  102 ; a piston  106  inserted in the cylinder  104  so as to perform a linear reciprocating motion and compress a fluid; a suction valve  108  installed to the front of the piston  106  to perform opening/closing operation so as to control the fluid flowing into the compression chamber  102 ; and a discharge valve assembly  110  for discharging the fluid from the compression chamber  102  to the outside when the fluid is compressed by higher than a certain level in the compression chamber  102 .  
         [0007]     In the piston  106  having a suction passage  112  for sucking a fluid is formed at the center thereof, and a suction hole  114  for supplying the fluid sucked into the suction passage  112  to a compressing chamber  102  is formed at the front thereof. And, a valve seat portion  116  on which the suction valve  108  is contacted is formed at the front of the piston  106 .  
         [0008]     The suction valve  108  is formed as a thin disc shape having a certain elastic force and is fixed to the valve seat portion  116  of the piston  106  by a bolt  118 .  
         [0009]     In more detail, as depicted in  FIG. 2 , the suction valve  108  includes a fixed portion  120  formed at the center thereof so as to fixed the valve seat portion  116  of the piston  106  by a bolt  118 , and an open/close portion  124  formed at one surface of the fixed portion  120  and opening/closing operation of the suction holes  114 . Herein, the fixed portion  120  and the open/close portion  124  are formed by cutting part of the suction valve  108  and are connected with each other by a neck portion  122  having a certain elastic force.  
         [0010]     And, the discharge valve assembly  110  includes a valve cover  132  installed at the front of the cylinder  104  and having a discharge hole  130  for discharging a fluid; a discharge valve  134  tightly contacted to the front of the cylinder  104  to perform opening/closing operation; and a spring  136  interposed between the discharge valve  134  and an internal wall of the valve cover  132  to provide a certain elastic force to the discharge valve  134 .  
         [0011]     The operation of the reciprocating compressor in accordance with the conventional art will be described. When the piston  106  is retreated in order to supply the fluid to the compression chamber  102 , because the open/close portion  124  of the suction valve  108  is separated from the valve seat portion  116  of the piston  106  by the suction pressure, the suction hole  114  is open, the fluid sucked into the suction passage  112  is supplied to the compression chamber  102  through the suction hole  114 .  
         [0012]     In that state, when the piston  106  is proceeded to compress the fluid, the suction valve  108  closes the suction hole  114  by being tightly contacted to the valve seat portion  116  of the piston  106  due to its own elastic force. When the piston  106  is proceeded more, the discharge valve  134  is separated from the cylinder  104  by the pressure inside the compression chamber  102 , and the fluid compressed in the compression chamber  102  is discharged to the outside through the discharge hole  130 .  
         [0013]     However, in the suction valve of the reciprocating compressor in accordance with the conventional art, when the fluid is supplied to the compression chamber  102 , by the suction pressure, the open/close portion  124  of the suction valve  108  is separated from the valve seat portion  116  of the piston  106 . Herein, because the open/close portion  124  performs the opening/closing operation of the suction hole  114  by bending the neck portion  122 , concentrated stress is acted on the neck portion  122 , and accordingly the neck portion  122  may be damaged by fatigue due to continuous opening/closing operation or excessive opening operation.  
         [0014]     In addition, because the open/close portion  124  has to be placed so as to face the suction holes  114  of the piston  106 , a position of the open/close portion  124  has to be adjusted accurately in an assembly process of the suction valve  108 . In addition, the fixed portion  120  has to be fixed firmly to the piston  106  in order to prevent a position of the open/close portion  124  from being changed in opening/closing of the suction valve  108 , and accordingly the assembly operation is intricate.  
       TECHNICAL GIST OF THE PESENT INVENTION  
       [0015]     In order to solve the above-described problems, it is an object of the present invention to provide a valve assembly of a reciprocating compressor capable of preventing damage or breakage of a valve by minimizing fatigue occurrence due to continuous opening/closing operation by reducing an opening angle of the valve.  
         [0016]     It is another object of the present invention to provide a valve assembly of a reciprocating compressor capable of improving productivity by assembling a valve regardless of a position thereof.  
         [0017]     In order to achieve the above-mentioned objects, a valve assembly of a reciprocating compressor in accordance with the present invention includes a piston having a valve seat portion at the front and plural suction holes for sucking a fluid at regular intervals in the circumferential direction; and a suction valve arranged at the valve seat portion to perform opening/closing operation of the suction holes, wherein the suction valve includes a fixed portion fixed to the valve seat portion of the piston; an open/close portion formed at the outside of the fixed portion to perform opening/closing operation of the suction holes; and plural neck portions formed between the fixed portion and the open/close portion at regular intervals.  
         [0018]     The fixed portion as the central portion of the suction valve is fixed to the center of the valve seat portion of the piston.  
         [0019]     The neck portion is formed between space portions formed by cutting portions between the fixed portion and the open/close portion at regular intervals.  
         [0020]     The neck portion is radially formed between space portions formed by cutting partial portions between the fixed portion and the open/close portion.  
         [0021]     A guide groove on which a fluid passing the suction hole is discharged is formed at the circumference of the open/close portion at regular intervals. 
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0022]     The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.  
         [0023]     In the drawings:  
         [0024]      FIG. 1  is a partial sectional view illustrating a suction valve of a compressor in accordance with the conventional art;  
         [0025]      FIG. 2  is an exploded perspective view illustrating the suction valve in accordance with the conventional art;  
         [0026]      FIG. 3  is a sectional view illustrating a compressor using a suction valve assembly in accordance with the present invention;  
         [0027]      FIG. 4  is an exploded perspective view illustrating the suction valve assembly in accordance with the present invention;  
         [0028]      FIG. 5  is a front view illustrating the suction valve assembly in accordance with the present invention;  
         [0029]      FIG. 6  is a sectional view illustrating an operational state of a suction valve in accordance with the present invention;  
         [0030]      FIG. 7  is a front view illustrating a suction valve assembly in accordance with a second embodiment of the present invention; and  
         [0031]      FIG. 8  is a front view illustrating a suction valve assembly in accordance with a third embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0032]     Hereinafter, the preferred embodiments a suction valve assembly of a compressor in accordance with the present invention will be described with reference to accompanying drawings.  
         [0033]     There can be plural embodiments, herein the preferred embodiments will be described.  
         [0034]      FIG. 3  is an perspective view illustrating a suction valve assembly of a reciprocating compressor in accordance with the present invention.  
         [0035]     The reciprocating compressor in accordance with the present invention includes a casing  6  having a certain sealed space and respectively connected suction pipe  2  for sucking a fluid and discharge pipe  4  for discharging a compressed fluid; a driving unit  8  disposed in the casing  6  to generate a reciprocating motion force when power is applied; and a compressing unit  10  for performing a compressing operation by receiving the reciprocating motion force generated in the driving unit  8 .  
         [0036]     The compressing unit  10  includes a piston  12  connected to the driving unit  8  to perform a linear reciprocating motion; a cylinder  14  for receiving the piston  12  slidably therein and forming a compression chamber  16 ; a suction valve  20  installed to the front of the piston  12  to perform opening/closing operation of a fluid passage  18  of the piston  12 ; and a discharge valve assembly  22  installed to the front of the cylinder  14  to perform opening/closing operation of a discharged fluid.  
         [0037]      FIGS. 4 and 5  are an exploded perspective and a front view illustrating the suction valve assembly in accordance with the present invention.  
         [0038]     The piston  12  is a cylindrical body connected to the driving unit  8  to perform a linear motion so as to be sealed by the inner circumference of the cylinder  14 , a suction passage  18  for sucking a fluid is formed at the inner circumference of the piston  12  in the length direction, and plural suction holes  24  are formed at the front of the piston  12  for supply the fluid sucked in the suction passage  18  to the compression chamber  16 . And, a flat valve seat portion  26  is formed at the front of the piston  12  so as to be tightly contacted to the suction valve  20  performing the opening/closing operation, and the driving unit  8  is connected to the rear of the piston  12 .  
         [0039]     Herein, the suction hole  24  is formed at regular intervals in the circumferential direction of the piston  12 . In more detail, the suction holes  24  can be formed freely at least they are formed in the circumferential direction of the piston  12  uniformly, as an embodiment, it is preferable to form eight suction holes.  
         [0040]     The suction valve  20  formed a thin flat plate type and fixed to the valve seat portion  26  of the piston  12  to opening/closeing the suction holes  24 , and it is made of a material having a certain elastic force.  
         [0041]     In the suction valve  20  having a fixed portion  28  is formed at the center thereof so as to be fixed to the valve seat portion  26  of the piston  12  and an open/close portion is formed at the outside of the fixed portion  28  to open/close the suction holes  24 .  
         [0042]     Herein, the fixed portion  28  and the open/close portion  30  are connected with each other by the neck portion  32 , the neck portion  32  is formed at regular intervals in the circumferential direction by space portions  34  formed by cutting portions between the fixed portion  28  and the open/close portion  30 , and each neck portion  32  has a certain elastic force. Each space portion  34  is formed as an elliptic shape having a certain size and is formed at regular intervals in the circumferential direction.  
         [0043]     The fixed portion  28  can have any structure at least it can fix the center of the suction valve  20  to the valve seat portion  26  of the piston  12 . As an embodiment, in case of a bolt fastening structure, a through hole  38  in which a bolt  36  is passed is formed at the center of the suction valve  20 , a bolt fastening groove  40  is formed at the center of the valve seat portion  26 , and accordingly the bolt  36  is fastened to the bolt fastening groove  40  after passing the through hole  38 .  
         [0044]     The open/close portion  30  has an area along the whole surface of the suction valve  20  in the circumferential direction, and the area of the open/close portion  30  is greater than a diameter of the suction hole  24  of the piston  12 .  
         [0045]     The discharge valve assembly  22  includes a valve cover  50  installed at the front of the cylinder  14  to have a discharge hole  46  for discharging a fluid; a discharge valve  48  placed in the valve cover  50  so as to be tightly contacted to the front of the cylinder  14  in order to perform opening/closing operation of a fluid compressed in the compression chamber  18 ; and a valve spring  52  interposed between the discharge valve  48  and an internal wall of the valve cover  50  to provide a certain elastic force to the discharge valve  48 .  
         [0046]     In more detail, when a pressure inside the compression chamber  16  reaches a certain degree, the discharge valve  48  is retreated by overcoming the elastic force of the valve spring  52 , the fluid compressed in the compression chamber  16  is discharged to the outside through the discharge hole  46 .  
         [0047]     The operation of the suction valve assembly of the reciprocating compressor in accordance with the present invention will be described.  
         [0048]      FIG. 6  is a sectional view illustrating an operational state of a suction valve in accordance with the present invention.  
         [0049]     First, when power is applied to the driving unit  8 , the driving force of the driving unit  8  is transmitted to the piston  12 , according to that, when the piston  12  is retreated, by the pressure difference of the fluid and the retreating inertia of the piston  12 , the neck portion  32  of the suction valve  20  is bent, the open/close portion  30  is separated from the valve seat portion of the piston  12 , the suction hole  24  is open, and accordingly the fluid is supplied to the compression chamber  24 .  
         [0050]     Herein, because the suction hole  24  is formed at the front of the piston  12  at regular intervals in the circumferential direction, the fluid is sucked through the plural suction holes  24 . Because, the neck portion  32  of the suction valve  20  is formed at regular intervals, it is possible to reduce an opening angle of the suction valve  20  and decrease concentrated stress acting on the neck portions  32 .  
         [0051]     In that state, when the driving unit  8  is operated in the backward direction, the piston  12  moves forward, the fluid filled in the compression chamber  16  is compressed, when a pressure inside the compression chamber  16  reaches a certain degree, the discharge valve  48  is retreated by overcoming the elastic force of the valve spring  52  and is separated from the front of the cylinder  14 , the fluid compressed in the compression chamber  16  is discharged to the outside through the discharge hole  46  formed at the valve cover  50 .  
         [0052]     Herein, by the pressure of the compression chamber  16  and the elastic force of the suction valve  20 , the open/close portion  30  of the suction valve  20  is tightly contacted to the valve seat portion  26  of the piston  12 , and accordingly it is possible to prevent the fluid inside the compression chamber  16  from flowing backward into the suction hole  24 .  
         [0053]      FIG. 7  is a front view illustrating a suction valve assembly in accordance with a third embodiment of the present invention.  
         [0054]     In a suction valve  58  in accordance with the second embodiment of the present invention having a fixed portion  60  having a through hole  62  is formed at the center thereof so as to be fixed to the valve seat portion  26  of the piston  12 , an open/close portion  64  formed at the outside of the fixed portion  60  for performing an opening/closing operation of the suction hole  24 , and plural neck portions  66  connected between the fixed portion  60  and the open/close portion  66 .  
         [0055]     Herein, the plural neck portions  66  are radially connected through space portions  68  formed by cutting portions between the fixed portion  60  and the open/close portion  64 . It is preferable to form four neck portions  66 , and the number of neck portions can be adjusted according to a pressure of the fluid.  
         [0056]      FIG. 8  is a front view illustrating a suction valve assembly in accordance with a third embodiment of the present invention.  
         [0057]     In a suction valve  70  in accordance with the third embodiment of the present invention having a fixed portion  72  is formed at the center so as to be fixed to the valve seat portion  26  of the piston  12 , an open/close portion  74  formed at the outside of the fixed portion  72  for performing opening/closing operation of the suction hole  24 , and plural neck portions  76  connected between the fixed portion  72  and the open/close portion  74 . And, a guide groove  78  is formed at the circumference of the open/close portion  74  in order to make the fluid passing the suction hole  24  be discharged smoothly.  
         [0058]     Herein, the guide groove  78  having a certain width is formed at the outer circumference of the suction valve  70  at regular intervals.  
       Industrial Applicability  
       [0059]     Advantages of a suction valve assembly of a reciprocating compressor in accordance with the present invention will be described as following.  
         [0060]     In the suction valve assembly of the reciprocating compressor in accordance with the present invention, because a suction hole of a piston is formed at regular intervals in the circumferential direction, a fluid is uniformly sucked in the circumferential direction, load acting on a whole surface of the suction valve is uniform, it is possible to reduce an opening angle of the suction valve, concentrated stress acting on a neck portion of the suction valve can be reduced, and accordingly it is possible to minimize damage of the suction valve.  
         [0061]     In addition, by forming the suction hole of the piston at regular intervals in the circumferential direction and forming the open/close portion of the suction valve in the circumferential direction, there is no need to adjust a position of the suction valve in an assembly process, and accordingly assembly efficiency can be improved.