U.S. patent application number 12/739372 was filed with the patent office on 2010-10-14 for discharge valve for linear compressor.
Invention is credited to Seong-Joon Hong, Dong-Han Kim, Jung-Hae Kim, Yoon-Seok Yang.
Application Number | 20100260635 12/739372 |
Document ID | / |
Family ID | 40580222 |
Filed Date | 2010-10-14 |
United States Patent
Application |
20100260635 |
Kind Code |
A1 |
Kim; Jung-Hae ; et
al. |
October 14, 2010 |
DISCHARGE VALVE FOR LINEAR COMPRESSOR
Abstract
A discharge valve is adapted to a linear compressor which is
elastically supported in an axial direction by a discharge valve
spring and which opens/closes a compression space defined between a
cylinder and a piston, the discharge valve comprising: a body made
from a metal material; and a coating layer made from a plastic
material to wrap the body. The linear compressor provided with such
a discharge valve is ensured with a satisfactory level of strength
with less use of materials.
Inventors: |
Kim; Jung-Hae; (Incheon,
KR) ; Yang; Yoon-Seok; (Incheon, KR) ; Hong;
Seong-Joon; (Gyeonggi-do, KR) ; Kim; Dong-Han;
(Seoul, KR) |
Correspondence
Address: |
MCKENNA LONG & ALDRIDGE LLP
1900 K STREET, NW
WASHINGTON
DC
20006
US
|
Family ID: |
40580222 |
Appl. No.: |
12/739372 |
Filed: |
October 10, 2008 |
PCT Filed: |
October 10, 2008 |
PCT NO: |
PCT/KR2008/005998 |
371 Date: |
April 22, 2010 |
Current U.S.
Class: |
417/550 |
Current CPC
Class: |
F04B 35/045
20130101 |
Class at
Publication: |
417/550 |
International
Class: |
F04B 53/10 20060101
F04B053/10 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 24, 2007 |
KR |
10-2007-0107371 |
Oct 24, 2007 |
KR |
10-2007-0107390 |
Claims
1. A discharge valve for a linear compressor which is elastically
supported in an axial direction by a discharge valve spring and
which opens/closes a compression space defined between a cylinder
and a piston, the discharge valve comprising: a body made from a
metal material; and a coating layer made from a plastic material to
wrap the body.
2. The discharge valve of claim 1, comprising: a center portion, on
which the discharge valve spring is settled; an expanded portion,
which expands in a radial direction of the center portion with a
uniform thickness and which has a plurality of reinforcement ribs;
and a rim portion, which is formed in a circumference direction of
the expanded portion with a uniform thickness.
3. The discharge valve of claim 2, wherein the reinforcement ribs
are uniformly arranged at the expanded portion along the
circumference direction.
4. The discharge valve of claim 2 or claim 3, wherein the
reinforcement ribs have a decreasing height in an outward direction
from the center portion to the rim portion.
5. The discharge valve of one of claims 2 through 4, wherein the
reinforcement ribs have a linear form.
6. The discharge valve of one of claims 2 through 5, wherein the
reinforcement ribs have a branched `Y-shaped` form in an outward
direction from the center portion to the rim portion.
7. The discharge valve of one of claims 1 through 6, wherein the
body is made from aluminum material, and the coating layer is made
from PEEK material.
8. The discharge valve of claim 1, comprising: a center portion on
which a discharge valve spring is settled; an expanded portion,
which expands in a radial direction of the center portion with a
decreasing thickness and which has a plurality of weight reduction
grooves; and a rim portion, which is formed in a circumference
direction of the expanded portion with a uniform thickness.
9. The discharge valve of claim 8, wherein the weight reduction
grooves are uniformly arranged at the expanded portion.
10. The discharge valve of claim 8 or claim 9, wherein the weight
reduction grooves form a molecular pattern where at least two
weight reduction grooves are arranged within a given section in a
circumference direction of the expanded portion.
11. The discharge valve of one of claims 8 through 10, wherein the
weight reduction grooves are arranged at the expanded portion in a
radiation pattern about the center portion.
12. The discharge valve of one of claims 8 through 11, wherein the
weight reduction grooves are arranged at the expanded portion with
a uniform depth.
13. The discharge valve of one of claims 8 through 12, wherein the
weight reduction grooves have a triangular shape.
14. The discharge valve of one of claims 8 through 12, wherein the
weight reduction grooves have a circular shape.
15. The discharge valve of claim 14, wherein four neighboring
weight reduction grooves are arranged in a diamond-shape.
Description
TECHNICAL FIELD
[0001] The present invention relates in general to a discharge
valve for a linear compressor, and more particularly, to a
discharge valve for a linear compressor, strength of which stays or
is secured at a satisfactory level with less use of materials.
BACKGROUND ART
[0002] In general, a reciprocating compressor is designed to form a
compression space to/from which an operation gas is
sucked/discharged between a piston and a cylinder, and the piston
linearly reciprocates inside the cylinder to compress
refrigerants.
[0003] Most reciprocating compressors today have a component like a
crankshaft to convert a rotation force of a drive motor into a
linear reciprocating drive force for the piston, but a problem
arises in a great mechanical loss by such motion conversion. To
solve the problem, development of linear compressors is still under
progress.
[0004] Linear compressors have a piston that is connected directly
to a linearly reciprocating linear motor, so there is no mechanical
loss by the motion conversion, thereby not only enhancing
compression efficiency but also simplifying the overall structure.
Moreover, since their operation is controlled by controlling an
input power to a linear motor, they are much less noisy as compared
to other compressors, which is why linear compressors are widely
used in indoor home appliances such as a refrigerator.
[0005] FIG. 1 illustrates one example of a linear compressor in
accordance with a prior art. The linear compressor has an
elastically supported structure inside a shell (not shown), the
structure including a frame 1, a cylinder 2, a piston 3, a suction
valve 4, a discharge valve assembly 5, a linear motor 6, a motor
cover 7, a supporter 8, a body cover 9, main springs S1 and S2, a
muffler assembly 10, and a mass member 20.
[0006] The cylinder 2 is insertedly fixed to the frame 1, and the
discharge assembly 5 constituted by a discharge valve 5a, a
discharge cap 5b, and a discharge valve spring 5c is installed to
cover one end of the cylinder 2. The piston 3 is inserted into the
cylinder 2, and the suction valve 4 which is very thin is installed
to open or close a suction port 3a of the piston 2.
[0007] The linear motor 6 is installed in a manner that a permanent
magnet 6c linearly reciprocates while maintaining the air-gap
between an inner stator 6a and an outer stator 6b. To be more
specific, the permanent magnet 6c is connected to the piston 3 with
a connecting member 6d, and an interactive electromagnetic force
between the inner stator 6a, the outer stator 6b, and the permanent
magnet 6c makes the permanent magnet 6c linearly reciprocating to
actuate the piston 3.
[0008] The motor cover 7 supports the outer stator 6b in an axial
direction to fix the outer stator 6b and is bolted to the frame 1.
The body cover 9 is coupled to the motor cover 7, and between the
motor cover 7 and the body cover 9 there is the supporter 8 that is
connected to the other end of the piston 3 while being elastically
supported in an axial direction by the main springs S1 and S2. The
muffler assembly 10 for sucking in refrigerant is also fastened to
the supporter 8.
[0009] Here, the main springs S1 and S2 include four front springs
S1 and four rear springs S2 that are arranged in horizontally and
vertically symmetrical positions about the supporter 8. As the
linear motor 6 starts running, the front springs S1 and the rear
springs S2 move in opposite directions and buff the piston 3 and
the supporter 8. In addition to these springs, the refrigerant in
the compression space P functions as sort of a gas spring to buff
the piston 3 and the supporter 8.
[0010] Therefore, when the linear motor 6 starts running, the
piston and the muffler assembly 10 connected to it move in a linear
reciprocating direction, and with the varying pressure in the
compression space P the operation of the suction valve 4 and the
discharge valve assembly 5 are automatically regulated. Under this
mechanism, the refrigerant flows via a suction pipe on the side of
the shell, an opening of the body cover 9, the muffler assembly 10,
and suction ports 3a of the piston 3 until it is sucked in the
compression space P and compressed. The compressed refrigerant then
escapes to the outside through the discharge cap 5b, the loop pipe
and an outlet duct on the side of the shell.
[0011] FIG. 2 illustrates one example of a discharge valve for a
linear compressor in accordance with a prior art. In one example, a
conventional discharge valve 5a is made from PEEK material which is
a kind of high-strength engineering plastics to be able to resist
the high internal pressure from the compression space P (see FIG.
1), and has a shape with an increasing thickness towards the
center. While one side of the discharge valve 5a is flat, the other
side is convex towards the center to stay rigid and not bent even
under excessive pressure. Naturally, the discharge valve 5a is
placed such that its flat side is in contact with one end of a
cylinder 2 (see FIG. 1) on the side of the compression space P (see
FIG. 1), while its convex side is elastically supported by a
discharge valve spring 5b (see FIG. 1).
[0012] FIG. 3 is a graph showing how the performance efficiency and
the noise being produced are related to an increasing weight of a
discharge valve for a linear compressor. According to the graph, as
the weight of a discharge valve increases, impact force generated
when the discharge valve collides with a cylinder increases,
producing a louder noise at the same time, but the performance
efficiency (compression efficiency) of a linear compressor is
degraded. Although a discharge valve of smaller weight would reduce
material costs and generate less noise, one should not reduce the
weight of the discharge valve too much in order to secure a
satisfactory level of strength for the discharge valve which is in
contact with the high-pressure compression space. Therefore, it is
desired to reduce the weight of a discharge valve within a range
where a satisfactory level of strength for the discharge valve is
ensured.
[0013] However, the discharge valve for a linear compressor
according to a prior art, although it is made from high-strength
yet expensive engineering plastics, is designed to be thicker
towards the center to ensure its strength, so problems like an
increase in weight and production cost, generation of louder noise
during operation in proportion to the weight, degraded compression
efficiency, etc., still remain unsolved. As most linear compressors
today have a greater capacity, a larger discharge valve is needed
accordingly, thereby making the aforementioned problems even
worse.
DISCLOSURE OF INVENTION
Technical Problem
[0014] The present invention is conceived to solve the
aforementioned problems in the prior art. An object of the present
invention is to provide a discharge valve for a linear compressor,
which features a satisfactory level of strength with reduced weight
by the use of dissimilar materials.
Technical Solution
[0015] According to an aspect of the present invention, there is
provided a discharge valve for a linear compressor which is
elastically supported in an axial direction by a discharge valve
spring and which opens/closes a compression space defined between a
cylinder and a piston, the discharge valve comprising: a body made
from a metal material; and a coating layer made from a plastic
material to wrap the body.
[0016] The discharge valve for a linear compressor of the present
invention comprises: a center portion, on which the discharge valve
spring is settled;
[0017] an expanded portion, which expands in a radial direction of
the center portion with a uniform thickness and which has a
plurality of reinforcement ribs; and a rim portion, which is formed
in a circumference direction of the expanded portion with a uniform
thickness.
[0018] In the discharge valve for a linear compressor of the
present invention, the reinforcement ribs are uniformly arranged at
the expanded portion along the circumference direction.
[0019] In the discharge valve for a linear compressor of the
present invention, the reinforcement ribs have a decreasing height
in an outward direction from the center portion to the rim
portion.
[0020] In the discharge valve for a linear compressor of the
present invention, the reinforcement ribs have a linear form.
[0021] In the discharge valve for a linear compressor of the
present invention, the reinforcement ribs have a branched
`Y-shaped` form in an outward direction from the center portion to
the rim portion.
[0022] In the discharge valve for a linear compressor of the
present invention, the body is made from aluminum material, and the
coating layer is made from PEEK material.
[0023] In another aspect, there is provided a discharge valve for a
linear compressor which is elastically supported in an axial
direction by a discharge valve spring and which opens/closes a
compression space defined between a cylinder and a piston, the
discharge valve comprising: a center portion on which a discharge
valve spring is settled; an expanded portion, which expands in a
radial direction of the center portion with a decreasing thickness
and which has a plurality of weight reduction grooves; and a rim
portion, which is formed in a circumference direction of the
expanded portion with a uniform thickness.
[0024] In the discharge valve for a linear compressor of the
present invention, the weight reduction grooves are uniformly
arranged at the expanded portion.
[0025] In the discharge valve for a linear compressor of the
present invention, the weight reduction grooves form a molecular
pattern where at least two weight reduction grooves are arranged
within a given section in a circumference direction of the expanded
portion.
[0026] In the discharge valve for a linear compressor of the
present invention, the weight reduction grooves are arranged in a
radiation pattern about the center portion.
[0027] In the discharge valve for a linear compressor of the
present invention, the weight reduction grooves are arranged at the
expanded portion with a uniform depth.
[0028] In the discharge valve for a linear compressor of the
present invention, the weight reduction grooves have a triangular
shape.
[0029] In the discharge valve for a linear compressor of the
present invention, the weight reduction grooves have a circular
shape.
[0030] In the discharge valve for a linear compressor of the
present invention, four neighboring weight reduction grooves are
arranged in a diamond-shape.
ADVANTAGEOUS EFFECTS
[0031] The discharge valve for a linear compressor with the
above-described configuration in accordance with the present
invention may not have an optimum strength but its total weight is
reduced by making the body from a relatively light metal material
and wrapping the body with the coating layer made from a
high-strength plastic material, such that a satisfactory level of
strength is ensured despite the reduction in weight. As such, a
linear compressor with the discharge valve of the present invention
provides advantages of reduced production cost, higher compression
efficiency while making less noise during the operation, reduced
installation space for the discharge valve to achieve a broader
space for discharge of refrigerant.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] FIG. 1 illustrates one example of a linear compressor in
accordance with a prior art;
[0033] FIG. 2 illustrates one example of a discharge valve for a
linear compressor in accordance with a prior art;
[0034] FIG. 3 is a graph illustrating how performance efficiency
and noise being generated by a conventional linear compressor
change by weight of a discharge valve adapted to the linear
compressor;
[0035] FIG. 4 illustrates one example of a linear compressor in
accordance with the present invention;
[0036] FIG. 5 illustrates a first embodiment of a discharge valve
for a linear compressor in accordance with the present
invention;
[0037] FIG. 6 illustrates a cross-sectional view taken along line
A-A of FIG. 5;
[0038] FIG. 7 illustrates a second embodiment of a discharge valve
for a linear compressor in accordance with the present
invention;
[0039] FIG. 8 illustrates a cross-sectional view taken along line
B-B of FIG. 7;
[0040] FIG. 9 illustrates a third embodiment of a discharge valve
for a linear compressor in accordance with the present invention;
and
[0041] FIG. 10 illustrates a fourth embodiment of a discharge valve
for a linear compressor in accordance with the present
invention.
MODE FOR THE INVENTION
[0042] Hereinafter, preferred embodiments of the present invention
will be described in detail with reference to the accompanying
drawings.
[0043] FIG. 4 illustrates one example of a linear compressor in
accordance with the present invention. In this example, a linear
compressor 100 of the present invention includes a cylinder 200, a
piston 300, and a linear motor 400 constituted by an inner stator
420, an outer stator 440, and a permanent magnet 460, which are
housed in a shell 110 or a hermetic container, and when the
permanent magnet 460 linearly reciprocates by an interactive
electromagnetic force between the inner stator 420 and the outer
stator 440, the piston 300 connected to the permanent magnet 460
also makes a linear reciprocating movement.
[0044] The inner stator 420 is affixed to an outer periphery of the
cylinder 200, and the outer stator 440 is secured axially by a
frame 520 and a motor cover 540. The frame 520 and the motor cover
540 are joined together by fastening members such as bolts, and the
outer stator 440 is secured between the frame 520 and the motor
cover 540. The frame 520 may be integrately formed with the
cylinder 200, or the frame 520 may be manufactured separately and
then coupled to the cylinder 200 later. The embodiment in FIG. 4
shows an example where the frame 520 and the cylinder 200 are
integrated as one body.
[0045] A supporter 320 is connected to the rear side of the piston
300. Four front main springs 820 are supported on both ends by the
supporter 320 and the motor cover 540. Also, four rear main springs
840 are supported on both ends by the supporter 320 and a back
cover 560, and the back cover 560 is coupled to the rear side of
the motor cover 540. A suction muffler 700 is provided on the rear
side of the piston 300, through which refrigerant flows into the
piston 300, so less noise is generated during suction feeding.
[0046] The interior of the piston 300 is hollowed to let the
refrigerant fed through the suction muffler 700 introduced and
compressed in a compression space P defined between the cylinder
200 and the piston 300. A suction valve 610 seats at the front end
of the piston 300. The suction valve 610 in the open position, the
refrigerant flows from the piston 300 into the compression space P,
and it shuts the front end of the piston 300 to prevent backflow of
the refrigerant from the compression space P to the piston 300.
[0047] When refrigerant inside the compression space P is
compressed to a predetermined level or higher, it causes a
discharge valve 620 which is seated at the front end of the
cylinder 200 to open. The discharge valve 620 is elastically
supported by a spiral discharge valve spring 630 inside a support
cap 640 that is secured to one end of the cylinder 200. The
high-pressure compressed refrigerant is then discharged into a
discharge cap 660 via a hole which is formed in the support cap
640, and then escapes from the linear compressor 110 via a loop
pipe L to be circulated, thereby making the refrigeration cycle
work.
[0048] All of the components of the linear compressor 100 described
above are supported by front and rear support springs 120 and 140
in assembled state, and stay at a certain distance away from the
bottom of the shell 110. Since they are not in direct contact with
the bottom of the shell 110, the shell 110 is free from the
influence of vibrations that are produced by each component of the
compressor 100 when compressing refrigerant. As a result, less
vibration is delivered to the outside of the shell 110 and
therefore, less noise is created due to the vibration of the shell
110.
[0049] FIG. 5 shows a first embodiment of a discharge valve for a
linear compressor in accordance with the present invention, and
FIG. 6 is a cross-sectional view taken along line A-A of FIG. 5. A
discharge valve 620 in accordance with the first embodiment of the
present invention includes a body 620A made from a relatively light
metal material such as aluminum, and a coating layer 620B made from
a high-strength plastic material such as PEEK to wrap the body.
Needless to say, the discharge valve 620 made from the
high-strength PEEK material only would not experience deformation
caused by pressure difference, but production cost will increase.
On the other hand, the discharge valve 620 made from an aluminum
material only would suffer severe deformation because of pressure
difference which outweighs the production cost advantage.
Therefore, it is recommended to manufacture discharge valves using
a variety of dissimilar materials that can reduce the weight and
guarantee a satisfactory level of strength at the same time.
[0050] By the use of dissimilar materials, the discharge valve 620
may take the form of a relatively thin disk as shown in FIG. 5,
which includes a spherical protruding holder 621 at the center to
receive a discharge valve spring 630 (see FIG. 4) thereon, an
expanded portion 622 that is expanded radially from the holder 621
at uniform thickness and that has parallel linear reinforcement
ribs 622a arranged in a circumference direction with a fixed
spacing from each other, and a rim 623 that is formed in the
circumference direction at uniform thickness to sustain the
pressure difference between inside and outside the compression
space P. At this time, the holder 621 is thickest as it has a
protruded portion to hold the discharge valve spring 630 (see FIG.
4), and the rim 623 has a relatively sufficient thickness to be
able to sustain the pressure difference between inside and outside
the compression space P. Meanwhile, the expanded portion 622 can be
thin compared to the holder 621 and the rim 623 because it is
already provided with the reinforcement ribs 622a. The
reinforcement ribs 622a are formed to have their height decreased
towards the rim 623 from the holder 621.
[0051] While one side of the discharge valve 620 has a stepped
surface because of the presence of the holder 621 for the discharge
valve spring 630 (see FIG. 4), the expanded portion 622 having the
reinforcement ribs 622a, and the rim 623, the other side of the
discharge valve 620 in contact with one end of the cylinder 200
(see FIG. 4) on the side of the compression space 2 has a flat
surface with a groove in which a bolt head for fastening the
suction valve 310 (see FIG. 4) slides.
[0052] FIG. 7 illustrates a second embodiment of a discharge valve
for a linear compressor in accordance with the present invention,
and FIG. 8 illustrates a cross-sectional view taken along line B-B
of FIG. 7. Similar to the discharge valve 620 of the first
embodiment, a discharge valve 1620 of the second embodiment
includes a body 1620A made from a relatively light metal material,
and a coating layer 1620B made from a high-strength plastic
material to wrap the body, and the body 1620A is provided with a
holder 1621, an expanded portion 1622, and a rim 1623. Because of
the structural similarity between two embodiments, a detailed
description on the structure will not be repeated. However, it
should be noted that the expanded portion 1622 in the second
embodiment includes `Y` shape reinforcement ribs 1622 which are
arranged in the circumference direction with a fixed spacing from
each other, being branched out towards the rim 1623 from the holder
1621. As such, even if the reinforcement ribs 1622a may have a
gradually decreasing height towards the rim 1623 from the holder
1621, a satisfactory level of strength can still be ensured.
[0053] FIG. 9 illustrates a third embodiment of a discharge valve
for a linear compressor in accordance with the present invention. A
discharge valve 2620 in accordance with the third embodiment of the
present invention includes a spherical protruding holder 2621 at
the center to receive a discharge valve spring 630 (see FIG. 4)
thereon, an expanded portion 2622 that is expanded radially from
the holder 2621 with decreasing thickness and that has a plurality
of uniformly-arrange weight reduction grooves 2622a, 2622b, 2622c,
2622d, and 2622e, and a rim 2623 that is formed in the
circumference direction of the extended portion 2622 at uniform
thickness to sustain the pressure difference between inside and
outside the compression space P (see FIG. 4). The weight reduction
grooves 2622a, 2622b, 2622c, 2622d, and 2622e form a molecular
pattern M by means of partition walls which are arranged in sort of
a molecular configuration, and such molecular patterns M are
uniformly arranged in the circumferential direction. Needless to
say, one side of the discharge valve 2620 in contact with the
compression space is flat, but the other side of the discharge
valve 2620 mounted with the discharge spring 630 (see FIG. 4) is
formed to have increasing thickness towards the center.
Nevertheless, the reduction of weight is still achieved because of
the presence of weight reduction grooves 2622a, 2622b, 2622c,
2622d, and 2622e.
[0054] In detail, the molecular pattern M is divided by partition
walls to have four triangular shaped weight reduction grooves
2622a, 2622b, 2622c, and 2622d, and one rectangular shaped weight
reduction groove 2622e, and all of the weight reduction grooves
2622a, 2622b, 2622c, 2622d, and 2622e formed in the extended
portion 2622 preferably have a uniform depth despite a varying
thickness of the extended portion 2622 according to the position.
Moreover, in order to ensure a satisfactory level of strength
contrary to the formation of the weight reduction grooves 2622a,
2622b, 2622c, 2622d, and 2622e, it is preferable to form corners,
i.e., crossing sites of partition walls, in a cylindrical shape and
thicker compared to other portions of the partition walls.
[0055] The discharge valve 2620 with the aforementioned
configuration can be formed by injection molding using
high-strength plastic materials such as PEEK.
[0056] FIG. 10 illustrates a fourth embodiment of a discharge valve
for a linear compressor in accordance with the present invention.
Similar to the discharge valve 2620 in the third embodiment, a
discharge valve 3620 of the fourth embodiment includes a holder
3621, an expanded portion 3622, and a rim 3623, where the expanded
portion 3622 has weight reduction grooves 3622a, 3622b, 3622c, and
3622d with uniform depth and circular shape that are arranged in a
radiation pattern about the holder 3621.
[0057] Here, the weight reduction grooves 3622a, 3622b, 3622c, and
3622d take the form of a pyramidal shape, and the number of the
grooves formed increases towards the rim 3623 from the holder 3621.
As indicated by dotted lines in FIG. 10, four neighboring weight
reduction grooves 3622a, 3622b, 3622c, and 3622d form sort of a
diamond-shaped molecular pattern M.
[0058] Moreover, similar to the discharge valve 2620 of the third
embodiment, the discharge valve 3620 of the fourth embodiment can
be formed by injection molding using high-strength plastic
materials such as PEEK. Yet, the discharge valve 3620 has a simple
structure compared as that of the third embodiment, and therefore
it is easily injection-molded, and it also features a simple mold
shape and a prolonged life.
[0059] The present invention has been described in detail with
reference to the embodiments and the attached drawings. However,
the scope of the present invention is not limited to the
embodiments and the drawings, but defined by the appended
claims.
* * * * *