Abstract:
A discharge apparatus for a reciprocating compressor. The compressor includes a shell connected to a gas suction conduit for sucking gas, a cylinder in the shell, a compression unit including a piston performing reciprocal movement in the cylinder, a reciprocating motor having an inner stator, an outer stator, and a armature performing reciprocal movement between them, and a frame unit for supporting the compression unit and the reciprocating motor by connecting them. The discharge apparatus includes a first cover member in which a valve body controlling the discharge of compressed gas by switching the cylinder in contained and at least a gas passage is formed, and a second cover member arranged continuously with the first cover member and connected to the gas discharge hole. In this way, the gas compressed by linear reciprocal movement of the piston in the cylinder is discharged smoothly so the reliability of the compressor operation is improved.

Description:
This application is the national phase under 35 U.S.C.  371 of PCT International Application No. PCT/KR01/00864 which has an International filing date of May 24, 2001, which designated the United States of America. 
     1. Technical Field 
     The present invention relates to a discharge apparatus of a reciprocating compressor, and particularly, a discharge apparatus of a reciprocating compressor, which is capable of attenuating noise of a compression pulse of a refrigerant discharged gas and operation of a hole compressor by designing a form of a cover member. 
     2. Background Art 
     In general, a discharge apparatus of a reciprocating compressor is constructed such that a piston of the compressor is integrally combined with the armature of a reciprocating motor and the piston, performing reciprocal movement in a cylinder rectilinearly, sucks gas and then discharges the gas compressed in the direction of the movement of the piston. FIG. 1 is a transverse cross-sectional view of the discharge apparatus of the reciprocating compressor. 
     As shown in FIG. 1, the discharge apparatus of a reciprocating compressor in accordance with the conventional art, includes a discharge cover  11  installed fixed having a certain discharge space Q on the front end surface of the reciprocating cylinder  2  and the piston  1  inserted to the apparatus and integrally combined with the armature of the reciprocating motor, a discharge valve  12  made of plastic and installed inside the discharge cover  11  for controlling discharge of compressive gas by switching (opening/closing) the cylinder  2  removed from the front end surface of the cylinder when the piston  1  performs reciprocal movement, and a valve spring  13  wherein the end is fixed on the inner wall of the discharge cover and the other end fixing the upper end for supporting the reciprocal movement of the discharge valve by the reciprocal movement of the piston  1  elastically having a form of a coil spring. 
     The discharge pipe  14  connected to the loop pipe (not shown) installed on an end of the discharge cover  11 , and the flange unit  11   a  is formed in the widely opened part. 
     The diameter of the discharge valve  12  is formed bigger than the inner diameter of the cylinder  2  and smaller than the inner diameter of the discharge cover  11 . The inner end surface opposite to the piston  1  is flat, and on the other hand, the outside end surface opposite to the discharge cover  11  is formed to be convex as a dome shape to be abutted to the cylindrical valve spring. 
     Reference numeral  1   a  designates a refrigerant channel, reference numeral  3  designates a suction valve, reference letter P designates a compression space, and reference letter Q designates a discharge space. 
     The above-described conventional discharge apparatus of a reciprocating compressor is operated as follows. 
     As shown in FIGS. 2 and 3, if the piston  1  formed integrally performs reciprocal movement with the armature of a reciprocating motor inside the cylinder  2 , the refrigerant gas is sucked into the compression space P of the cylinder  2  through the refrigerant channel  1   a  formed inside the piston  1  and discharged out through the discharge space Q of the discharge cover  11  repeatedly. 
     Namely, if the piston  1  is on the suction stroke, a new refrigerant gas flows into the compression space P through the refrigerant channel  1   a  opening the suction valve  3  installed on the front end surface. 
     The refrigerant gas flowed in the compression space P is pushed and compressed during the compression stroke of the piston  1 , and from a certain moment, the refrigerant gas pushes the discharge valve  12 . 
     The compression gas filled in the discharge space Q is pushed by the discharge valve  12  and discharged out through the discharge pipe  14 . 
     At the same time, the refrigerant gas compressed in the compression space P flows into the discharge space Q through the gap between the discharge valve  12  and the discharge cover  11 . 
     Then, during the suction stroke of the piston  1 , the pressure is relatively lower in the compression space P than in discharge space Q and the discharge valve  12  is restored, mounted to the front end surface of the cylinder  2 , and divides the compression space P and the discharge space Q by the restoring force of the valve spring  13 . 
     However, in the conventional discharge apparatus of the reciprocating compressor above, the compressed gas is discharged to the discharge cover in the process of discharging the compressed refrigerant gas switching the discharge valve repeatedly, and then the pressure pulse in the discharge cover increases. Therefore, noise in the discharge cover increases and the shock noise, generated when the discharge valve  12  is bumped into the front end surface of the cylinder by switching the discharge valve  12 , is not able to be diminished sufficiently. 
     Also, in case of installing the compressor having the discharge apparatus, the loop pipe connected to the discharge apparatus receives pressure pulse, and accordingly, the secondary noise is generated when the refrigerator itself vibrates in response to the increased vibration level. 
     SUMMARY OF THE INVENTION 
     Therefore, it is an object of the present invention to provide a discharge apparatus of a reciprocating compressor to attenuate noise resulted from compression pulse in the discharge cover and shock generated when switching the discharge valve, and prevent the vibration level of the loop pipe connected to the discharge cover from rising. 
     To achieve these objects, there is provided a discharge apparatus of a reciprocating compressor comprising, a shell connected to a gas suction conduit or sucking gas, a cylinder in the shell, a compression unit including a piston performing reciprocal movement in the cylinder, a reciprocating motor having an inner stator, an outer stator, and an armature performing reciprocal movement between them, and a frame unit for supporting the compression unit and the reciprocating motor by connecting them, consist of a first cover member in which a valve body controlling the discharge of compressed gas by switching the cylinder in contained and at least a gas passage is formed, and a second cover member arranged continuously with the first cover member and connected to the gas discharge hole. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a transverse cross-sectional view showing a discharge apparatus of a reciprocating compressor in accordance with the conventional art. 
     FIG. 2 is a transverse cross-sectional view showing an operation of the discharge apparatus of a reciprocating compressor in accordance with the conventional art. 
     FIG. 3 is a transverse cross-sectional view showing an operation of the discharge apparatus of a reciprocating compressor in accordance with the conventional art. 
     FIG. 4 is a front sectional view showing first embodiment of a discharge apparatus of a reciprocating compressor in accordance with the present invention. 
     FIG. 5 is a plane view showing a multi-plenum cover composing the first embodiment of a discharge apparatus of a reciprocating compressor in accordance with the present invention. 
     FIG. 6 is a front-sectional view showing an operation status of the first embodiment of a discharge apparatus of a reciprocating compressor in accordance with the present invention. 
     FIG. 7 is a front-sectional view showing an operation status of the first embodiment of a discharge apparatus of a reciprocating compressor in accordance with the present invention. 
     FIG. 8 is a front-sectional view showing a second embodiment of a discharge apparatus of a reciprocating compressor in accordance with the present invention. 
     FIG. 9 is a plane cross-sectional view showing a second embodiment of a discharge apparatus of a reciprocating compressor in accordance with the present invention. 
     FIG. 10 is a front-sectional view of a showing a second embodiment of a discharge apparatus of a reciprocating compressor in accordance with the present invention. 
     FIG. 11 is a plane cross-sectional showing a multi-plenum cover composing the first embodiment of a discharge apparatus of a reciprocating compressor in accordance with the present invention. 
     FIG. 12 is a front-sectional view showing multi-plenum cover composing the first embodiment of a discharge apparatus of a reciprocating compressor in accordance with the present invention. 
     FIG. 13 is a plane view showing an operation status of a discharge apparatus of a reciprocating compressor in accordance with the present invention. 
     FIG. 14 is a front-sectional view showing the other embodiment of the first embodiment of a discharge apparatus of a reciprocating compressor in accordance with the present invention. 
     FIG. 15 is a front-sectional view showing the other embodiment of the second embodiment of a discharge apparatus of a reciprocating compressor in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The discharge apparatus of a reciprocating compressor according to the present invention will be described with reference to the embodiments in the accompanying drawings. 
     The same components as those of the conventional art are designated by the same reference numerals, and an explanation of their same operation are omitted. 
     Hereinafter, the first embodiment of the present invention will be described. 
     As shown in FIG. 4, the discharge apparatus of a reciprocating compressor according to the present invention includes a reciprocating piston  10  receiving driving force from the vibration apparatus unit, which generates driving force, a compression space P in which gas is compressed by the piston  10  and cylinder  20 , and a discharge valve assembly  112 , for discharging compressed gas by switching (opening/closing) the compression space P in accordance with the movement of the piston  10  inside the discharge cover  111  to cover the compression space P, and the discharge valve assembly  112  is composed of a discharge valve  112   a  for switching the compression space P and a spring  112   b  for supporting the discharge valve  112   a.    
     Also, a multi-plenum cover  170  covering the discharge cover  111  forms discharge spaces with the periphery of the discharge cover  111  covering the discharge cover  111  is combined and a plurality of the gas passages  11   a  are formed through the outside wall of the discharge cover  111  to make the gas discharged to inside the discharge cover  111  flow to the plurality of the buffer spaces f in the multi-plenum cover  170 . 
     The discharge hole  171  for discharging gas flown to the buffer space of the multi-plenum cover  170  is formed in one of the plurality of buffer spaces f. 
     Also, a plurality of gas passages  111   a  are formed to connect the inner part of the discharge cover  111  and the buffer space f, and it is desirable that the multi-plenum cover  170  has buffer spaces f to be a form of a four-leaf clover. 
     Namely, as shown in FIG. 5, the outside wall is formed by symmetrically curved portions having a certain thickness, and a space having a form as a cross is formed inside the discharge cover  111 , 
     A plurality of buffer spaces are formed by the periphery of the discharge cover  111  and inside of the multi-plenum cover  170 . 
     On the other hand, the inside height of the buffer space f is formed to be higher than that of the discharge cover  111 , and accordingly, a joint space g, which each buffer space f is formed to connect the buffer space f and the collateral part between the outside end surface of the discharge cover  111 , and the discharge hole  171  is also formed in one of the plurality of the buffer spaces. 
     Also, the gas passage  111   a  connected with the discharge cover  111  in the upper part of the joint space g can be formed on the upper end additionally to improve efficiency of the compressor by increasing discharge gas. 
     Also, as shown in FIG. 14, another embodiment is possible by combining the central cover  300  between the discharge cover and the multi-plenum cover  170  so that the efficiency of the buffer space f is improved. 
     At that time, the central cover  300  can be a cover formed as a simple cap or a multi-plenum cover. It is desirable to combine these covers in accordance with the noise characteristics of the discharge apparatus. 
     Also, the number of the plurality of buffer spaces f can be sequentially increased from, but if the noise characteristics in the range of 2˜4 kHz, wherein noise is currently problematic and the examination of the noise characteristics are considered, it is most desirable that 4 buffer spaces f are formed symmetrically. 
     In addition, the desirable diameter of the discharge hole is less than 5 mm, but for practical embodiments, forming a 2˜4 mm diameter is desirable. 
     Also, on one side of the circumference in the outermost cover of the covers, whether it is the multi-plenum cover or the cover formed as a simple cap, a convex unit  180  is formed and functions as a stopper to prevent the inside wall of the shell and other important parts from bumping into each other during the operation of the reciprocating compressor in accordance with the present invention. 
     The convex unit  180  is desirable to be located in a part, wherein the crest hump does not interrupt the power connector formed on the circumference. 
     The discharge cover  111  and the central cover  300  are desirable to be pressed fit and formed integrally, and as an example of the combination, brazing is used. 
     Hereinafter, the effect of the discharge apparatus of reciprocating compressor in accordance with the present invention will be described as follows. 
     Firstly, the piston  10 , receiving driving force from the electromotive apparatus performs reciprocal movement, and as shown in FIG. 6, the piston  10  moves from the upper dead center H to the low dead center L. Then the discharge valve  112   a , composing the discharge valve assembly  112 , closes up the compression space P of the cylinder at the same time as gas is sucked into the compression space P of the cylinder  20 . 
     Then, as shown in the FIG. 7, when the piston  10  moves from the lower dead center L to the upper dead center H, the piston  10  reaches the upper dead center H compressing the gas sucked into the compression space P, and when a certain compression state is achieved, the compressed gas is discharged in response to opening of the discharge valve  112   a  supported by the spring  112   b  elastically. 
     The process that the compressed gas is discharged in the compression space is as follows. As the discharge valve  112   a  is opened, the compressed gas flown to the discharge space Q in the discharge cover  111  and at the same time, the gas flows in the buffer space f formed by the outside of the discharge cover  111  through the gas passage  111   a  formed in the discharge cover  111  and inside of the multi-plenum cover  710 . Then the gas flown to the buffer space g flows into the joint space and respective buffer spaces f through the discharge hole  171 , and the gas is discharged out. 
     Also, as the gas compressed in the compression space P is discharged through the discharge path, the noise of pulses, from the flowing gas generated from inside the discharge cover  111  and the shock noise of valve are minimized. 
     Namely, by the buffer space f formed by the outside of the discharge cover  111  and the multi-plenum cover  170 , the volume of the discharge plenum region is increased 5 times compared with the conventional structure, and as a result, the performance to attenuate the pulses of discharge compression with low frequency is improved. Also, the plurality of buffer spaces offset the compression waves of the generated noise can be removed due to the structure of having a plurality of buffer spaces f remarkably. 
     In addition, in the present invention the structure of the compressor can be simple and assembly is easy to perform by processing and pressing the discharge cover  111  and the central cover  300 . 
     Hereinafter, the second embodiment of the reciprocating compressor in accordance with the present invention will be described. 
     As shown in FIGS. 8,  9 , and  10 , the second embodiment of the reciprocating compressor in accordance with the present invention includes a structure as follows. The discharge cover  211 , wherein the piston  10  covers the compression space of the reciprocating cylinder  20 , has a gas passage  211   a  on the one end, and a plurality of connected buffer spaces  273  inside the piston pressed and combined with the outside of the discharge cover  211  are formed. Also, one of the buffer spaces  273  communicates with a discharge hole  271  to allow refrigerant gas from the gas passage  211   a  to pass sequentially through the plurality of the buffer spaces  273  and out the discharge hole  271 . 
     The discharge cover  211  includes a communication passage  213  formed as an annular groove by the stepped edge in the body unit  212  formed as a cylinder, wherein an end is blocked, a compartment dividing unit  214  for dividing the communication passage  213 , a gas passage  211   a  formed near the compartment dividing unit for connecting the inside of the discharge cover  211  and the communication passage  213  and a first coupled parts  215  bent to have a certain area on the edge the body unit  212 . 
     Namely, a cylindrical insertion unit  216  is connected to the body unit  212  of the discharge cover  211  having a smaller periphery than that of the body unit  212  and having a certain height, and as a result, the communication passage  213  is formed between the periphery of the insertion unit  216  and the inside of the multi-plenum cover  270 . 
     The compartment dividing unit  214  divides the communication passage  213  into two portions because it is formed to have a lower height that that of the insertion unit  216  in the stepped surface N composing the communication passage  213  and the same width as the stepped surface N. 
     The first coupled parts  215  is formed to have a certain area as a flange shape, and an appropriate holes  217  are formed at an opposite portion symmetric to the fist coupled part  215  of the insertion unit  216 . 
     Hereinafter, the structure of the multi-plenum cover  270  will be described in detail. 
     As shown in FIGS. 11 and 12, the multi-plenum cover is formed having the space formation unit  274  to form a plurality of buffer spaces  273  connected side-by-side to the circular insertion space  272  wherein the insertion unit  216  of the discharge cover in the direction of the circumference, an insertion hole penetrated in the space formation unit  274  so that the insertion unit  216  of the discharge cover  211  is protruded in case it bumps into the discharge cover  211  in the space formation unit  274 , and the second coupled parts  276  formed to have a certain area on the side of an end of the space formation unit  274 . 
     Also, the buffer space  273  is formed having a certain symmetrical interval, and second coupled parts  275  is desirable to be located in response to the first coupled parts  215 . 
     The inner diameter of the insertion space  272  is formed to have a same outer diameter as that of the body unit  212  of the discharge cover, and the inner diameter of the insertion space  272  is formed to be bigger than that of the insertion unit  216  of the discharge cover  211 . 
     Also, the discharge cover  211  is inserted so that the insertion unit  216  is protruded on the insertion hole  275  of the multi-plenum cover  270 . The lower end surface of the multi-plenum cover  270  is abutted to the upper end surface of the compartment asperity unit  214 , and the first coupled parts  215  and the second coupled parts  276  are abutted to each other. 
     At this time, the body part  212  of the discharge cover  216  is located in the insertion space  272  inside the multi-plenum cover  270 , and a plurality of buffer spaces  273  are formed by the circumference surface of the insertion unit  216 , the body unit  212 , the inner upper surface, and the inner circumferential surface of the multi-plenum cover  270 , and the plurality of the buffer spaces  273  is connected with each other through the communication passage  213 . 
     The communication channel formed by the communication passage  213  is divided to two parts by the compartment asperity unit  214 . 
     In addition, the discharge hole  271  of the multi-plenum cover  270  is located in the opposite side to the gas passage  211   a  centering around the compartment asperity unit  214 . 
     Also, as shown in FIG. 15, another embodiment by combining the central cover  400  having a multi-plenum between the discharge cover  211  and the simple cap cover  270  is possible to operate to improve the effect of the buffer space  273 . At this time, the central cover  400  can be either a multi-plenum cover or a simple cap cover, and the covers are desirable to be compounded to use in accordance with the noise characteristic of the discharge apparatus. However, in case of the second embodiment it is desirable to form the central cover  400  as a multi-plenum cover, and the outermost cover as a simple cap cover  211 ′. On one end of the circumferential surface of the multi-plenum cover protruded out of the outermost cover, a convex unit  280  is formed and functions as a stopper to prevent the inside wall of the shell and another important parts from bumping into each other during the operation of the reciprocating compressor in accordance with the present invention. 
     Also, the number of the plurality of buffer spaces  273  can be increased from one in order, but if the noise characteristics of the area of 2˜4 kHz, wherein noise is currently problematic and the examination of the noise characteristics are considered, it is most desirable that 4 buffer spaces  273  are formed symmetrically. 
     In addition, the desirable diameter of the discharge hole is less than 5 mm, but for the referred embodiment, forming a 2˜4 mm diameter is desirable. 
     The convex unit  180  is desirable to be located in a part, wherein the convex unit  180  does not interrupt the power connector formed on the circumference. 
     The discharge cover  211  and the central cover  211 ′ are desirable to be processing as press fit and brazing. 
     Hereinafter, the assembly of the discharge apparatus of reciprocating compressor in accordance with the present invention will be described. 
     The discharge cover  211  is combined with the multi-plenum cover  270  covering the compression space P of the cylinder  20 , and the piston  10  is inserted enabled to perform reciprocating movement. The piston  10  is connected to the vibration apparatus unit and combines with the discharge valve and the valve spring  112   b  for supporting the discharge valve  112   a  elastically to switch the compression space P of the cylinder  20 . 
     Hereinafter, the effect of the second embodiment of the discharge apparatus of reciprocating compressor in accordance with the present invention will be described. 
     Firstly, the piston  10 , receiving driving force from the vibration apparatus performs reciprocal movement, and the discharge valve  112   a  closes up the compression space P at the same time as gas is sucked to the compression space P, compressed, and discharged. 
     The discharged gas on the status of high pressure and temperature, as shown in FIG. 13, flows into the inner space of the discharge cover  211 , and then the gas flows into the buffer space  273  of the multi-plenum cover  270  and the circumferential surface of the discharge cover  211  through the gas passage  211   a . The gas flown to the buffer space  273  is discharged out through the discharge hole  271  passing each buffer space  273  in order by the communication passage  213 . 
     Therefore, noise of compression pulse and valve switching generated from the process of discharging refrigerant gas is removed passing the same process as discharging gas. 
     Also, the principal of the Helm-Holz resonator is applied to the composition with the plurality of the buffer spaces  273  and the communication passage  213 . 
     The invention has applicability to reciprocating compressors as are employed widely in various industrial fields. As so far described, the discharge apparatus of a reciprocating compressor is not only able to discharge compressed gas in the compression space in accordance with the rectilinear and reciprocal movement of the piston in a cylinder smoothly, but it is also able to minimize noise by removing the discharge pulse and valve switching noise of a certain bandwidth generated from inside the compressor sucking, compressing, and discharging gas thus to improve the reliability of the compressor operation.