Patent Grant
8057200
This application claims priority to International application No. PCT/KR2007/000269 filed on Jan. 16, 2007 which claims priority to Korean Application No. 10-2006-0004646 filed Jan. 16, 2006, both of which are incorporated by reference, as if fully set forth herein.
The present invention relates to a linear compressor in which a piston is linearly reciprocated inside a cylinder, for sucking a refrigerant into a compression space between the piston and the cylinder, and compressing and discharging the refrigerant, and more particularly, to a structure of discharging a refrigerant for a linear compressor which can reduce a pulsation of a high pressure discharged refrigerant, by making the refrigerant compressed in a compression space flow from a sub-discharge space with a relatively small volume to a sub-discharge space with a relatively large volume in a discharge cap.
Referring to
Here, the compression space P for compressing the refrigerant is formed between one end of the cylinder 2 and the piston 4. A suction hole 4h is formed at one end of the piston 4 in the axial direction, for sucking the refrigerant into the compression space P, and a thin film type suction valve 6 is bolt-fastened to one end of the piston 4, for opening and closing the suction hole 4h. A discharge valve assembly 8 is installed at one end of the cylinder 2, for discharging the refrigerant compressed in the compression space P.
The linear motor 10 includes a ring-shaped inner stator 12 formed by laminating a plurality of laminations in the circumferential direction, and fixed to the outer circumference of the cylinder 2, a ring-shaped outer stator 14 formed by laminating a plurality of laminations in the circumferential direction outside a coil winding body formed by winding a coil in the circumferential direction, and disposed outside the inner stator 12 with an interval, and a permanent magnet 16 disposed in the space between the inner stator 12 and the outer stator 14, and linearly reciprocated by a mutual electromagnetic force by the inner stator 12 and the outer stator 14.
One end of the inner stator 12 is supported by the main body frame 3, and the other end thereof is fixed to the outer circumference of the cylinder 2 by a fixing ring (not shown). In addition, one end of the outer stator 14 is supported by the main body frame 3, and the other end thereof is supported by a motor cover 22. The motor cover 22 is bolt-fastened to the main body frame 3. The permanent magnet 16 is connected to the other end of the piston 4 by a connection member 30.
When a current is applied to the outer stator 14, the permanent magnet 16 is linearly reciprocated by the mutual electromagnetic force by the inner stator 12 and the outer stator 14, and the piston 4 is linearly reciprocated inside the cylinder 2. As a pressure inside the compression space P is varied, the suction valve 6 and the discharge valve assembly 8 are operated to suck, compress and discharge the refrigerant.
The conventional structure of discharging the refrigerant for the linear compressor will now be explained with reference to
In detail, the discharge valve assembly 8 includes a discharge valve 8a for opening and closing one end of the cylinder 2, a support cap 8b fixed to one end of the cylinder 2, for covering the discharge valve 8a, and a discharge valve spring 8c for elastically opening and closing the discharge valve 8a on one end of the cylinder 2 according to the pressure inside the compression space P.
Communication holes H1, H2, H3 and H4 for discharging the refrigerant to the discharge cap 9 are formed on the circumference of the support cap 8b at intervals. The discharge spaces 9a, 9b, 9c and 9d are formed on the discharge cap 9 to correspond to the communication holes H1, H2, H3 and H4, respectively. The discharge spaces 9a, 9b, 9c and 9d communicate to each other.
As the piston 4 is linearly reciprocated inside the cylinder 2, the refrigerant sucked into the compression space P is compressed. If the pressure inside the compression space P exceeds a set pressure, the discharge valve spring 8c is compressed to open the discharge valve 8a. The high pressure refrigerant of the compression space P is passed through the communication holes H1, H2, H3 and H4 of the support cap 8b, temporarily collected in the discharge chamber D inside the discharge cap 9, reduced in vibration and noise through the relatively thin and long loop pipe R, and externally discharged.
In the conventional structure of discharging the refrigerant for the linear compressor, the refrigerant compressed at a high pressure in the compression space P by linear reciprocation of the piston 4 generates a pulsation, passes through the communication holes H1, H2, H3 and H4 formed on the circumference of the support cap 8b of the discharge valve assembly 8 at intervals, and is discharged to the discharge chamber D which is one up-down and left-right symmetric limited space. That is, even if the pulsation is generated in the high pressure refrigerant, the refrigerant flows through the loop pipe P. Therefore, the pulsation of the refrigerant is maintained high, which increases noise and vibration.
An object of the present invention is to provide a structure of discharging a refrigerant for a linear compressor which can externally discharge the refrigerant with its pulsation reduced, by making the refrigerant sequentially pass through discharge spaces with different volumes, even if the high pressure refrigerant is discharged from a compression space, generating the pulsation.
There is provided a structure of discharging a refrigerant for a linear compressor, comprising: a cylinder in which the refrigerant flows in the axial direction; a piston reciprocated inside the cylinder to compress a fluid; a discharge valve assembly installed at one end of the cylinder and opened and closed to discharge the refrigerant; and a discharge cap covering the discharge valve assembly, and having a discharge space partitioned into different sizes of sub-discharge spaces that the refrigerant is discharged from the discharge valve assembly to the discharge space, for reducing a pulsation of the refrigerant by making the refrigerant flow from the sub-discharge space with a relatively small volume to the sub-discharge space with a relatively large volume. By this configuration, when the refrigerant flows, the volumes of the refrigerant flowing spaces are changed to reduce the pulsation of the refrigerant.
In another aspect of the present invention, the structure of discharging the refrigerant further includes a first loop pipe having its one end connected to the sub-discharge space with the large volume in the discharge cap, and guiding external discharge of the refrigerant. By this configuration, the refrigerant can be externally discharged from the compressor with its pulsation reduced.
In another aspect of the present invention, the discharge valve assembly includes a communication hole for discharging the refrigerant to the sub-discharge space with the small volume. By this configuration, the refrigerant is discharged to the sub-discharge space with the small volume, and easily transferred to the sub-discharge space with the large volume.
In another aspect of the present invention, the structure of discharging the refrigerant further includes: a first loop pipe having its one end connected to the discharge cap, and guiding external discharge of the refrigerant; and a buffering cap connected to the other end of the first loop pipe, for reducing the pulsation. By this configuration, the refrigerant is externally discharged from the compressor after the pulsation thereof is reduced once more.
In another aspect of the present invention, the buffering cap has a smaller volume than the discharge cap. By this configuration, the volumes of the refrigerant flowing spaces are changed to more reduce the pulsation of the refrigerant.
In another aspect of the present invention, the discharge cap further includes an additional sub-discharge space which is smaller than the sub-discharge space with the large volume and larger than the sub-discharge space with the small volume between the sub-discharge space with the large volume and the sub-discharge space with the small volume. By this configuration, since the refrigerant undergoes the volume changes of the flowing spaces a few times, the pulsation of the refrigerant can be considerably reduced.
In another aspect of the present invention, the structure of discharging the refrigerant further includes a second loop pipe having its one end connected to the buffering cap, and guiding the refrigerant to be externally discharged from the buffering cap.
In another aspect of the present invention, the other end of the first loop pipe and one end of the second loop pipe are installed at an interval from each other inside the buffering cap. By this configuration, since the refrigerant flows from the other end of the first loop pipe to one end of the second loop pipe inside the buffering cap, the pulsation of the refrigerant is reduced.
In another aspect of the present invention, any one of the other end of the first loop pipe and one end of the second loop pipe is positioned more deeply in the buffering cap.
And there is provided a structure of discharging a refrigerant for a linear compressor, comprising: a cylinder in which the refrigerant flows in the axial direction; a piston reciprocated inside the cylinder, for compressing a fluid; a discharge valve assembly installed at one end of the cylinder and opened and closed, discharging the refrigerant; and a discharge cap for covering the discharge valve assembly, the discharge cap being partitioned into a plurality of sub-discharge spaces with a small volume and one sub-discharge space with a large volume that the refrigerant are discharged from the discharge valve assembly to the sub-discharge spaces, for reducing a pulsation of the refrigerant by making the refrigerant flow from the sub-discharge spaces with the relatively small volume to the sub-discharge space with the relatively large volume.
The discharge cap is partitioned off the sub-discharge spaces with the small volume and the sub-discharge space with the large volume according to its curved shape. By this configuration, the pulsation of the refrigerant can be suppressed without using an additional member.
In another aspect of the present invention, the sub-discharge spaces with the small volume and the sub-discharge space with the large volume are arranged along an outer circumference of a discharge valve. By this configuration, since the discharge spaces are arranged on the same plane surface, the structure of reducing the pulsation of the refrigerant can be provided without increasing the whole size of the compressor.
And there is provided a structure of discharging a refrigerant for a linear compressor, comprising: a cylinder in which the refrigerant flows in the axial direction; a piston reciprocated inside the cylinder, for compressing a fluid; a discharge valve assembly installed at one end of the cylinder and opened and closed, for discharging the refrigerant; a discharge cap having a discharge space to which the refrigerant is discharged from the discharge valve assembly; a first loop pipe having its one end connected to the discharge cap, and guiding the refrigerant to be externally discharged from the discharge cap; and a buffering cap connected to the other end of the first loop pipe, for reducing a pulsation of the refrigerant. By this configuration, since the refrigerant is discharged to the discharge cap, and then discharged to the buffering cap through the first loop pipe, the pulsation of the refrigerant is reduced.
In another aspect of the present invention, the structure of discharging the refrigerant further includes a frame on which one end of the cylinder is installed, and the buffering cap is installed on the frame. By this configuration, the buffering cap can be fixed without using a special frame for installing the buffering cap. It is thus possible to efficiently use the inside space of the linear compressor.
The buffering cap has a smaller volume than the discharge cap. By this configuration, the volumes of the refrigerant discharge spaces are changed to efficiently reduce the pulsation of the refrigerant.
The structure of discharging the refrigerant further includes a second loop pipe having its one end connected to the buffering cap, and guiding the refrigerant to be externally discharged from the buffering cap. Any one of the other end of the first loop pipe and one end of the second loop pipe is positioned more deeply in the buffering cap. By this configuration, when the refrigerant is supplied from the discharge cap to the buffering cap through the first loop pipe, the pulsation of the refrigerant is always reduced in the buffering cap. Thereafter, the refrigerant is externally discharged from the buffering cap through the second loop pipe.
In accordance with the present invention, in the structure of discharging the refrigerant for the linear compressor, when the piston is linearly reciprocated inside the cylinder, the refrigerant is compressed and discharged to the discharge cap regardless of generation of the pulsation. As the refrigerant flows from the sub-discharge space with the relatively small volume to the sub-discharge space with the relatively large volume in the discharge cap, the pulsation of the refrigerant can be reduced. Furthermore, since the refrigerant sequentially passes through the predetermined volumes of discharge cap and buffering cap and then flows into the second loop pipe, the pulsation of the refrigerant can be reduced. As a result, vibration and noise generated by the pulsation of the refrigerant can be efficiently suppressed.
A stricture of discharging a refrigerant for a linear compressor in accordance with the preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.
As illustrated in
The discharge space D1 is defined by a discharge valve assembly 58 and a discharge cap 59, and the buffering space D2 is defined by the frame 3 and a buffering cap 60.
In detail, one end of the cylinder 2 passes through the frame 3. A compression space P is formed inside one end of the cylinder 2, and the discharge valve assembly 58 is installed outside one end of the cylinder 2 to be opened and closed.
Especially, the discharge valve assembly 58 includes a discharge valve 58a for opening and closing one end of the cylinder 2, a support cap 58b isolated to cover the discharge valve 58a, and fixed to one end of the cylinder 2, and a discharge valve spring 58c for elastically supporting the discharge valve 58a on the support cap 58b.
The portion of the discharge valve 58a contacting one end of the cylinder 2 is formed flat, and the opposite portion thereof is upwardly protruded toward the center portion, namely, convex. Therefore, the discharge valve 58a can resist a high pressure of the compression space P. Preferably, a settling groove (not shown) is formed on the discharge valve 58a, for supporting the discharge valve spring 58c.
The diameter of one end of the discharge valve spring 58c contacting the discharge valve 58a is smaller than that of the other end of the discharge valve spring 58c contacting the support cap 58b, thereby stably supporting the discharge valve 58a. The opened end of the support cap 58b is fixed to the frame 3 adjacent to the circumference of one end of the cylinder 2, and the closed end of the support cap 58b supports the discharge valve spring 58c. Preferably, a plurality of communication holes H1, H2 and H3 are formed on the circumference of the support cap 58b, for discharging the refrigerant.
Preferably, three communication holes H1, H2 and H3 are formed on the circumference of the support cap 58b at intervals of 90 in the circumferential direction. The inside shape of the discharge cap 59 is determined according to the communication holes H1, H2 and H3, which will later be explained in detail.
Accordingly, if the pressure inside the compression space P is over a set pressure, the discharge valve spring 58c is compressed, one side of the discharge valve 58a is opened from one end of the cylinder 2, and thus the high pressure refrigerant is discharged to the discharge cap 59 through each communication hole H1, H2 and H3.
The discharge cap 59 covers the support cap 58b with an interval from the support cap 58b. The opened end of the discharge cap 59 is fixed to the frame 3 to completely cover the support cap 58b.
In more detail, the first, second, third and fourth sub-discharge spaces 59a, 59b, 59c and 59d are formed inside the discharge cap 59 to communicate with each other. Here, the first, second and third sub-discharge spaces 59a, 59b and 59c have a relatively small volume, and the fourth sub-discharge space 59d has a relatively large volume. The first, second, third and fourth sub-discharge spaces 59a, 59b, 59c and 59d are formed in the discharge cap 59 at intervals of 90 in the circumferential direction.
Preferably, the discharge cap 59 covers the support cap 58b so that the communication holes H1, H2 and H3 of the support cap 58b can correspond to the first, second and third sub-discharge spaces 59a, 59b and 59c of the discharge cap 59, respectively.
One example of the structure in which the communication holes H1, H2 and H3 of the support cap 58b correspond to the first, second and third sub-discharge spaces 59a, 59b and 59c of the discharge cap 59 will now be explained. The high pressure refrigerant discharged from the communication holes H1, H2 and H3 of the support cap 58b is distributed to the first, second and third sub-discharge spaces 59a, 59b and 59c of the discharge cap 59 with the relatively small volume, and then collected in the fourth sub-discharge space 59d of the discharge cap 59 with the relatively large volume. Thus, the pulsation of the refrigerant is reduced.
Another example of forming the first, second, third and fourth sub-discharge spaces 59a, 59b, 59c and 59d will now be described. The first sub-discharge space 59a has the smallest volume, the second and third sub-discharge spaces 59b and 59c have a larger volume than the first sub-discharge space 59a, and the fourth sub-discharge space 59d has the largest volume. That is, this structure reduces the pulsation of the refrigerant discharged from the first sub-discharge space 59a once more. As a result, the pulsation of the refrigerant is considerably suppressed.
In addition to the communication holes H1, H2 and H3 formed on the support cap 58b in the circumferential direction, a communication hole H4 can be formed at the center portion of the support cap 58b. As the refrigerant discharged from the communication hole H4 also flows to the fourth sub-discharge space 59d in the discharge cap 59, the pulsation of the refrigerant is reduced.
The buffering cap 60 has a smaller volume than the discharge cap 59. The opened end of the buffering cap 60 is fixed to the frame 3 so that the buffering cap 60 can be disposed at one side of the discharge cap 59.
Preferably, the discharge cap 59 is sufficiently large to reduce the pressure of the refrigerant, when the high pressure refrigerant is discharged from the compression space P. However, since the buffering cap 60 merely reduces the pulsation of the refrigerant transferred from the discharge cap 59, the volume of the buffering cap 60 can be set smaller than that of the discharge cap 59.
Although the discharge cap 59 and the buffering cap 60 are fixedly installed on the frame 3, since one surface of the frame 3 is not flat, the discharge cap 59 and the buffering cap 60 are not disposed on the same plane surface.
The first loop pipe R1 and the second loop pipe R2 are pipes with a small diameter. The first loop pipe R1, which is relatively short, is installed between the discharge cap 59 and the buffering cap 60, for guiding flow of the refrigerant. The second loop pipe R2, which is relatively long, is installed between the buffering cap 60 and the external space to guide flow of the refrigerant and reducing noise by the pulsation of the refrigerant.
The first loop pipe R1 communicates with the fourth sub-discharge space 59d of the discharge cap 59, so that the refrigerant collected in the fourth sub-discharge space 59d of the discharge cap 59 can be discharged to the buffering cap 60.
In the case of the first loop pipe R1, a thin pipe can be installed in a straight line shape. In the case of the second loop pipe R2, a thin and long pipe is preferably curvedly installed to efficiently reduce vibration and noise of the refrigerant. In order to minimize vibration and noise of the refrigerant, a buffering member (not shown) such as rubber can be installed in a section of the second loop pipe R2 in consideration of a vibration frequency of the refrigerant.
Especially to buffer the pulsation of the refrigerant in the buffering cap 60, the end of the first loop pipe R1 and the end of the second loop pipe R2 are preferably disposed in the opposite directions in the buffering cap 60 to be distant from each other. More preferably, the end of the first loop pipe R1 is disposed deeply at one end of the buffering cap 60, and the end of the second loop pipe R2 is connected to the other end of the buffering cap 60, so that the high pressure refrigerant supplied into the buffering cap 60 through the first loop pipe R1 can be buffered in the buffering cap 60 and discharged along the second loop pipe R2.
The process of discharging the refrigerant in the structure of discharging the refrigerant for the linear compressor in accordance with the present invention will now be described.
When the piston 4 is linearly reciprocated in the cylinder 2, if the pressure inside the compression space P is below a set pressure, a thin suction valve 6 installed at one end of the piston 4 is opened so that the refrigerant can pass through an inflow hole 4h of the piston 4 and flow into the compression space P. The pressure inside the compression space P is raised, and the refrigerant is compressed in the states of the suction valve 6 and the discharge valve 58a closed. If the pressure inside the compression space P is over the set pressure, the discharge valve spring 58c is compressed so that one side of the discharge valve 58a can partially open one end of the cylinder 2.
When one side of the discharge valve 58a is opened, the high pressure refrigerant is discharged from the compression space P, and transferred to the discharge cap 59 through the communication holes H1, H2, H3 and H4 of the support cap 58b. As the volume of the high pressure refrigerant increases in the discharge cap 59, the pressure thereof can be partially reduced.
Since the piston 4 is continuously linearly reciprocated inside the cylinder 2, the high pressure refrigerant is discharged from the compression space P to the discharge cap 59, generating the pulsation. However, when the refrigerant flows from the first, second and third sub-discharge spaces 59a, 59b and 59c of the discharge cap 59 with the relatively small volume to the fourth sub-discharge space 59d of the discharge cap 59 with the relatively large volume, the pulsation of the refrigerant is partially reduced.
The pulsation of the refrigerant discharged from the compression space P is reduced in the discharge cap 59. The refrigerant is discharged from the discharge cap 59, and supplied to the buffering cap 60 through the first loop pipe R1.
The end of the first loop pipe R1 is disposed deeply in the buffering cap 60, and the end of the second loop pipe R2 is disposed in the opposite direction to the end of the first loop pipe R1 in the buffering cap 60. When the refrigerant is transferred from the first loop pipe R1 to the buffering cap 60 with the relatively large volume, the pulsation of the refrigerant is buffered. Thereafter, the refrigerant flows into the second loop pipe R2.
When the refrigerant flows through the second loop pipe R2 which is the relatively thin and long pipe, the pressure, vibration and noise of the refrigerant are reduced at the same time. The buffering member installed on the second loop pipe R2 improves the effect of reducing the vibration and noise of the refrigerant.
Since the piston 4 is repeatedly linearly reciprocated inside the cylinder 2, the high pressure refrigerant is continuously discharged through the discharge cap 59, the first loop pipe R1, the buffering cap 60 and the second loop pipe R2.
Although the preferred embodiments of the present invention have been described, it is understood that the present invention should not be limited to these preferred embodiments but various changes and modifications can be made by one skilled in the art within the spirit and scope of the present invention as hereinafter claimed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2006-0004646 | Jan 2006 | KR | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/KR2007/000269 | 1/16/2007 | WO | 00 | 7/15/2008 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2007/081193 | 7/19/2007 | WO | A |
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| Number | Date | Country | |
|---|---|---|---|
| 20090081054 A1 | Mar 2009 | US |
