U.S. patent application number 11/470005 was filed with the patent office on 2007-05-17 for linear compressor.
This patent application is currently assigned to LG ELECTRONIC INC.. Invention is credited to Ki Chul CHOI, Seon Woong HWANG, Hong Hee PARK.
Application Number | 20070110600 11/470005 |
Document ID | / |
Family ID | 37692607 |
Filed Date | 2007-05-17 |
United States Patent
Application |
20070110600 |
Kind Code |
A1 |
PARK; Hong Hee ; et
al. |
May 17, 2007 |
Linear Compressor
Abstract
Disclosed herein is a linear compressor in which a piston
reciprocally moves in a cylinder upon receiving a reciprocating
drive force of a linear motor to compress working-fluid, for
example, refrigerant, received in the cylinder. The linear
compressor comprises a piston adapted to reciprocally move in a
cylinder, the piston being internally formed with a suction path,
and a suction valve inserted in the suction path of the piston to
move relative to the suction path, the suction valve performing
opening/closing operations as it moves relative to the piston when
the piston reciprocally moves. With this configuration, the suction
valve always exhibits an even stroke, achieving an improvement in
response and durability and minimizing vibration and noise due to
the opening/closing operations thereof.
Inventors: |
PARK; Hong Hee; (Seoul,
KR) ; HWANG; Seon Woong; (Anyang-si, KR) ;
CHOI; Ki Chul; (Seoul, KR) |
Correspondence
Address: |
GREENBLUM & BERNSTEIN, P.L.C.
1950 ROLAND CLARKE PLACE
RESTON
VA
20191
US
|
Assignee: |
LG ELECTRONIC INC.
20 Yeoeuido-dong, Youngdeungpo-ku
Seoul
KR
|
Family ID: |
37692607 |
Appl. No.: |
11/470005 |
Filed: |
September 5, 2006 |
Current U.S.
Class: |
417/417 ;
417/545 |
Current CPC
Class: |
F04B 39/0016 20130101;
F04B 35/045 20130101 |
Class at
Publication: |
417/417 ;
417/545 |
International
Class: |
F04B 35/04 20060101
F04B035/04 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 14, 2005 |
KR |
10-2005-0108699 |
Claims
1. A linear compressor comprising: a piston adapted to reciprocally
move in a cylinder, the piston being internally formed with a
suction path; and a suction valve inserted in the suction path of
the piston to move relative to the suction path, the suction valve
performing opening/closing operations as it moves relative to the
piston when the piston reciprocally moves.
2. The compressor as set forth in claim 1, wherein the piston is
also formed with a suction valve recess such that the suction valve
is completely inserted into the piston.
3. The compressor as set forth in claim 1, wherein the piston is
also formed with a suction valve recess such that the suction valve
is completely inserted into the piston, the suction valve recess
being configured to gradually widen away from the suction path of
the piston toward a distal end of the piston.
4. The compressor as set forth in claim 1, wherein: the piston is
also formed with a suction valve recess such that the suction valve
is completely inserted into the piston, the suction valve recess
having an inclined region where it comes into contact with the
suction valve; and the suction valve has an inclined surface to
come into surface contact with the inclined region of the suction
valve recess when the suction valve is inserted into the suction
valve recess.
5. A linear compressor comprising: a piston adapted to reciprocally
move in a cylinder, the piston being internally formed with a
suction path; and a suction valve including: a suction valve body
adapted to open or close the suction path of the piston as it moves
relative to the suction path when the piston reciprocally moves,
the suction valve body being formed with an elongated slot
extending in a reciprocating movement direction of the piston; and
a suction valve guide pin fitted through the piston and the slot of
the suction valve body to move relative to the suction valve body
while being fixed to the piston.
6. The compressor as set forth in claim 5, wherein the suction
valve body has: a head portion disposed to protrude out of the
suction path of the piston; and a body portion configured to move
into or out of the suction path of the piston, the body portion
having a partially cut-away cross sectional shape to allow the
passage of working-fluid.
7. The compressor as set forth in claim 6, wherein the body portion
has a D-cut shape for the passage of the working-fluid.
8. The compressor as set forth in claim 6, wherein the piston is
also formed with a suction valve recess such that the suction valve
is completely inserted into the piston.
9. The compressor as set forth in claim 6, wherein the piston is
also formed with a suction valve recess such that the suction valve
is completely inserted into the piston, the suction valve recess
being configured to gradually widen away from the suction path of
the piston toward a distal end of the piston.
10. The compressor as set forth in claim 6, wherein: the piston is
also formed with a suction valve recess such that the suction valve
is completely inserted into the piston, the suction valve recess
having an inclined region where it comes into contact with the
suction valve; and the suction valve has an inclined surface to
come into surface contact with the inclined region of the suction
valve recess when the suction valve is inserted into the suction
valve recess.
11. The compressor as set forth in claim 5, wherein the suction
valve body has: a head portion disposed to protrude out of the
suction path of the piston; and a body portion configured to have a
diameter smaller than a diameter of the suction path of the piston
to move into or out of the suction path of the piston.
12. The compressor as set forth in claim 11, wherein the piston is
also formed with a suction valve recess such that the suction valve
is completely inserted into the piston.
13. The compressor as set forth in claim 11, wherein the piston is
also formed with a suction valve recess such that the suction valve
is completely inserted into the piston, the suction valve recess
being configured to gradually widen away from the suction path of
the piston toward a distal end of the piston.
14. The compressor as set forth in claim 11, wherein the piston is
formed with a suction valve recess such that the suction valve is
completely inserted into the piston, the suction valve recess
having an inclined region where it comes into contact with the
suction valve; and the suction valve has an inclined surface to
come into surface contact with the inclined region of the suction
valve recess when the suction valve is inserted into the suction
valve recess.
15. The compressor as set forth in claim 5, wherein the suction
valve body has: a head portion disposed to protrude out of the
suction path of the piston; and a body portion configured to move
into or out of the suction path of the piston, the body portion
having holes for allowing the passage of working-fluid.
16. The compressor as set forth in claim 15, wherein the holes of
the body portion are integrally formed with a slot of the suction
valve body.
17. The compressor as set forth in claim 15, wherein the piston is
also formed with a suction valve recess such that the suction valve
is completely inserted into the piston.
18. The compressor as set forth in claim 15, wherein the piston is
also formed with a suction valve recess such that the suction valve
is completely inserted into the piston, the suction valve recess
being configured to gradually widen away from the suction path of
the piston toward a distal end of the piston.
19. The compressor as set forth in claim 15, wherein: the piston is
formed with a suction valve recess such that the suction valve is
completely inserted into the piston, the suction valve recess
having an inclined region where it comes into contact with the
suction valve; and the suction valve has an inclined surface to
come into surface contact with the inclined region of the suction
valve recess when the suction valve is inserted into the suction
valve recess.
20. The compressor as set forth in claim 5, wherein the suction
valve body has a flat outer surface at an opposite side of the
piston.
21. A linear compressor comprising: a piston adapted to
reciprocally move in a cylinder, the piston being internally formed
with a suction path; and a suction valve including: a suction valve
body adapted to open or close the suction path of the piston as it
moves relative to the suction path when the piston reciprocally
moves, the suction valve body being formed with an elongated slot
extending in a reciprocating movement direction of the piston; and
a suction valve guide pin fitted through the piston and the slot of
the suction valve body to move relative to the suction valve body
while being fixed to the piston, wherein: the piston is also formed
with a suction valve recess such that the suction valve is
completely inserted into the piston, the suction valve recess being
configured to gradually widen away from the suction path of the
piston toward a distal end of the piston; and the suction valve has
an inclined surface to come into surface contact with the inclined
region of the suction valve recess when the suction valve is
inserted into the suction valve recess.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention The present invention relates to a
linear compressor, and more particularly, to a linear compressor in
which a suction valve performs opening/closing operations as it
moves relative to a piston by an inertial force when the piston
reciprocally moves.
[0002] 2. Description of the Related Art Generally, a linear
compressor is an apparatus configured in such a fashion that a
piston reciprocally moves in a cylinder upon receiving a
reciprocating drive force of a linear motor, to compress
working-fluid received in the cylinder, for example, refrigerant.
The linear compressor is mainly used in refrigerators, etc.
[0003] FIG. 1 is a sectional view illustrating a conventional
linear compressor. FIG. 2 is a view of important parts of the
conventional linear compressor, illustrating the advance movement
of a piston. FIG. 3 is a view of important parts of the
conventional linear compressor, illustrating the retraction
movement of the piston.
[0004] As shown in FIGS. 1 to 3, the conventional linear compressor
comprises a shell 2 forming the outer appearance of the compressor,
a cylinder block 4 and a back cover 6 which are arranged in the
shell 2, and a compression unit provided between the cylinder block
4 and the back cover 6. The compression unit serves to compress
working-fluid by a desired compression ratio.
[0005] The shell 2 is provided with a fluid suction pipe 8 and a
fluid discharge pipe 9, such that the working-fluid to be
compressed is sucked into the compression unit from the outside of
the shell 2, and then, is again discharged out of the shell 2 after
being compressed in the compression unit.
[0006] The compression unit includes a cylinder 10 having a
compression chamber 11 in which the working-fluid, having passed
through the fluid suction pipe 8, is compressed, a piston 20 to
compress the working-fluid received in the compression chamber 11
of the cylinder 10 while performing reciprocating movements in the
cylinder 10, and a linear motor 30 to reciprocally move the piston
20.
[0007] The cylinder 10 is provided with a discharge valve assembly
12, such that the working-fluid, compressed in the compression
chamber 11 of the cylinder 10, is discharged into the fluid
discharge pipe 9 in accordance with the operation of the discharge
valve assembly 12.
[0008] The piston 20 is internally formed with a suction path 21
for allowing the working-fluid, having passed through the fluid
suction pipe 8, to be sucked into the cylinder 10. Also, the piston
20 has a suction valve 22 to open or close the suction path 21.
[0009] The suction valve 22 is an elastic member fastened to the
piston 20 by means of a bolt B. The suction valve 22 is designed to
be opened or closed as it is elastically deformed in accordance
with a pressure difference between the suction path 21 of the
piston 20 and the interior of the cylinder 10.
[0010] The linear motor 30 basically includes a stator 32, and a
mover 34. The mover 34 is adapted to reciprocally move while
electromagnetically interacting with the stator 32. The mover 34 is
connected to the piston 20.
[0011] The compression unit further includes a main spring assembly
40 for providing the piston 20 with an elastic force in a
reciprocating movement direction of the piston 20. Thus, the main
spring assembly 40 allows vibrations of the piston 20 to some
extent when the piston 20 reciprocally moves.
[0012] The main spring assembly 40 consists of a first main spring
42 located between the back cover 6 and the piston 20, and a second
main spring 44 located between the cylinder 10 and the linear motor
30 to be supported by the cylinder block 4 and the piston 20.
[0013] The operation of the conventional linear compressor having
the above-described configuration will now be explained.
[0014] If the linear motor 30 is driven, the piston 20 reciprocally
moves in the cylinder 10 upon receiving the drive force of the
linear motor 30. Then, the first and second main springs 42 and 44
are repeatedly compressed and tensioned in accordance with the
reciprocating movements of the piston 20, thereby serving to allow
vibrations of the piston 20 to some extent while causing the
discharge valve assembly 12 and the suction valve 22 to be
repeatedly opened or closed.
[0015] Thereby, the working-fluid is sucked into the compression
chamber 11 of the cylinder 10 through the fluid suction pipe 8,
such that it is compressed to a high-pressure state by the piston
20 in the compression chamber 11 of the cylinder 10. Subsequently,
the compressed working-fluid is discharged from the cylinder 10
through the discharge valve assembly 12, to be discharged out of
the shell 2 through the fluid discharge pipe 9.
[0016] The suction, compression, and discharge operations of the
working fluid as stated above are continuously repeated in this
sequence so long as the linear motor 30 is driven.
[0017] A problem of the above-described conventional linear
compressor is that the suction valve 22 of the linear compressor is
adapted to use an elastic force thereof, and therefore, may exhibit
different elastic strains in accordance with a pressure difference
between the suction path 21 of the piston 20 and the interior of
the cylinder 10. This makes it impossible for the linear compressor
to achieve improved constant compression efficiency, and results in
deterioration of reliability.
[0018] In particular, the suction valve 22 using an elastic force
may exhibit excessive elastic deformation as shown in FIG. 3 when a
pressure difference between the suction path 21 of the piston 20
and the interior of the cylinder 10 is large or liquid phase
working-fluid is introduced into the cylinder 10. Accordingly,
there is a high risk in that the suction valve 22 may be
plastically deformed or damaged due to an increased stress.
Furthermore, the suction valve 22 suffers from deterioration of
durability with the lapse of time, and consequently has a poor
response property.
[0019] Excessive elastic deformation of the suction valve 22 also
exposes the piston 20 to severe shock. This is due to an increase
of stress as well as inordinate vibration and noise.
[0020] Another problem of the conventional linear compressor is
that, when the bolt B is used to fasten the suction valve 22 to the
piston 20, a bolt head inevitably protrudes into the compression
chamber 11 of the cylinder 10, increasing the dead volume of the
compression chamber 11 of the cylinder 10. This results in
deterioration of compression efficiency. Also, if the bolt head
directly collides with the discharge valve assembly 12, the bolt
head may be severely damaged, and excessive vibration and noise may
be generated.
[0021] Recently, high-density nitrogen dioxide is widely used as
working fluid. However, the use of the nitrogen dioxide working
fluid requires a relatively reduced diameter of the piston 20.
Thus, in this case, it is very difficult to fasten the suction
valve 22 to the piston 20 by use of the bolt B, and the piston 20
suffers from an increased flow resistance.
SUMMARY OF THE INVENTION
[0022] Therefore, the present invention has been made in view of
the above problems, and it is an object of the present invention to
provide a linear compressor in which a suction valve performs
opening/closing operations as it moves relative to a piston by an
inertial force, rather than an elastic force, when the piston
reciprocally moves, whereby the suction valve can always exhibit an
even opening/closing stroke, achieving several advantageous
effects, for example, improved constant compression efficiency,
little risk of deformation or damage, high response and durability,
and minimized vibration and noise.
[0023] In accordance with one aspect of the present invention, the
above and other objects can be accomplished by the provision of a
linear compressor comprising: a piston adapted to reciprocally move
in a cylinder, the piston being internally formed with a suction
path; and a suction valve inserted in the suction path of the
piston to move relative to the suction path, the suction valve
performing opening/closing operations as it moves relative to the
piston when the piston reciprocally moves.
[0024] Preferably, a suction valve may be adapted to open or close
the suction path of the piston as it moves relative to the suction
path when the piston reciprocally moves, the suction valve
including: a suction valve body formed with an elongated slot
extending in a reciprocating movement direction of the piston; and
a suction valve guide pin fitted through the piston and the slot of
the suction valve body to move relative to the suction valve body
while being fixed to the piston.
[0025] Preferably, the suction valve body may have: a head portion
disposed to protrude out of the suction path of the piston; and a
body portion configured to move into or out of the suction path of
the piston, the body portion having a partially cut-away cross
sectional shape to allow the passage of working-fluid.
[0026] Preferably, the body portion may have a D-cut shape for the
passage of the working-fluid.
[0027] Preferably, the suction valve body may have: a head portion
disposed to protrude out of the suction path of the piston; and a
body portion configured to have a diameter smaller than a diameter
of the suction path of the piston to move into or out of the
suction path of the piston.
[0028] Preferably, the suction valve body may have: a head portion
disposed to protrude out of the suction path of the piston; and a
body portion configured to move into or out of the suction path of
the piston, the body portion having holes for allowing the passage
of working-fluid.
[0029] Preferably, the holes of the body portion may be integrally
formed with a slot of the suction valve body.
[0030] Preferably, the piston may be also formed with a suction
valve recess such that the suction valve is completely inserted
into the piston.
[0031] Preferably, the piston may be also formed with a suction
valve recess such that the suction valve is completely inserted
into the piston, the suction valve recess being configured to
gradually widen away from the suction path of the piston toward a
distal end of the piston.
[0032] Preferably, the piston may be also formed with a suction
valve recess such that the suction valve is completely inserted
into the piston, the suction valve recess having an inclined region
where it comes into contact with the suction valve; and the suction
valve has an inclined surface to come into surface contact with the
inclined region of the suction valve recess when the suction valve
is inserted into the suction valve recess.
[0033] In accordance with another aspect of the present invention,
the above and other objects can be accomplished by the provision of
a linear compressor comprising: a piston adapted to reciprocally
move in a cylinder, the piston being internally formed with a
suction path; and a suction valve adapted to open or close the
suction path of the piston as it moves relative to the suction path
when the piston reciprocally moves, the suction valve including: a
suction valve body formed with an elongated slot extending in a
reciprocating movement direction of the piston; and a suction valve
guide pin fitted through the piston and the slot of the suction
valve body to move relative to the suction valve body while being
fixed to the piston, wherein: the piston is also formed with a
suction valve recess such that the suction valve is completely
inserted into the piston, the suction valve recess having an
inclined region where it comes into contact with the suction valve;
and the suction valve has an inclined surface to come into surface
contact with the inclined region of the suction valve recess when
the suction valve is inserted into the suction valve recess.
[0034] In the linear compressor of the present invention having the
above-described configuration, the suction valve is inserted in the
suction path of the piston to move relative to the suction path,
thereby performing opening/closing operations as it moves relative
to the piston by an inertial force when the piston reciprocally
moves, whereby the suction valve always exhibits an even
opening/closing stroke, and therefore, can achieve various
advantageous effects, such as for example, improved constant
compression efficiency, little deformation or damage due to
excessive stress applied to the suction valve, an improvement in
response and durability, and minimized vibration and noise caused
by the opening/closing operations of the suction valve.
[0035] Further, as a result of providing the suction valve guide
pin in the piston in a radial direction of the piston to couple the
suction valve to the piston, it is possible to minimize the dead
volume of the compression chamber of the cylinder, to enable the
suction valve to be easily mounted to the piston even if the piston
has a small diameter, and to reduce the flow resistance of
working-fluid due to the existence of the suction valve.
[0036] Furthermore, since the piston is formed with the suction
valve recess such that the suction valve is completely inserted
into the piston when the suction valve closes the suction path of
the piston, the dead volume of the cylinder chamber of the cylinder
can be more effectively eliminated, and there is no risk of
interference between the suction valve and a discharge valve
assembly.
[0037] Finally, by providing the suction valve with an inclined
head portion, the head portion of the suction valve can come into
surface contact with the suction valve recess of the piston,
whereby the suction valve can smoothly move into or out of the
suction valve recess of the piston, and in particular, the head
portion of the suction valve can achieve an improved stiffness.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] The above and other objects, features and other advantages
of the present invention will be more clearly understood from the
following detailed description taken in conjunction with the
accompanying drawings, in which:
[0039] FIG. 1 is a sectional view illustrating a conventional
linear compressor;
[0040] FIG. 2 is a view of important parts of the conventional
linear compressor, illustrating the advance movement of a
piston;
[0041] FIG. 3 is a view of important parts of the conventional
linear compressor, illustrating the retraction movement of the
piston;
[0042] FIG. 4 is a sectional view illustrating a linear compressor
according to a first embodiment of the present invention;
[0043] FIG. 5 is an exploded perspective view illustrating a
suction valve and a piston included in the linear compressor
according to the first embodiment of the present invention;
[0044] FIG. 6 is a view illustrating an initially retracted state
of the piston of the linear compressor according to the first
embodiment of the present invention;
[0045] FIG. 7 is a view illustrating a completely retracted state
of the piston of the linear compressor according to the first
embodiment of the present invention;
[0046] FIG. 8 is a view illustrating an initially advanced state of
the piston of the linear compressor according to the first
embodiment of the present invention;
[0047] FIG. 9 is a view illustrating a completely advanced state of
the piston of the linear compressor according to the first
embodiment of the present invention;
[0048] FIG. 10 is a configuration view of important parts of a
linear compressor according to a second embodiment of the present
invention, illustrating a retracted state of a piston included in
the linear compressor;
[0049] FIG. 11 is a configuration view of important parts of the
linear compressor according to the second embodiment of the present
invention, illustrating an advanced state of the piston;
[0050] FIG. 12 is a configuration view of important parts of a
linear compressor according to a third embodiment of the present
invention, illustrating a retracted state of a piston included in
the linear compressor;
[0051] FIG. 13 is a configuration view of important parts of the
linear compressor according to the third embodiment of the present
invention, illustrating an advanced state of the piston;
[0052] FIG. 14 is a configuration view of important parts of a
linear compressor according to a fourth embodiment of the present
invention, illustrating a retracted state of a piston included in
the linear compressor; and
[0053] FIG. 15 is a configuration view of important parts of the
linear compressor according to the fourth embodiment of the present
invention, illustrating an advanced state of the piston.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0054] Now, preferred embodiments of the present invention will be
explained with reference to the accompanying drawings.
[0055] FIG. 4 is a sectional view illustrating a linear compressor
according to a first embodiment of the present invention. FIG. 5 is
an exploded perspective view illustrating a suction valve and a
piston included in the linear compressor according to the first
embodiment of the present invention. FIGS. 6 to 9 are views
illustrating, in this sequence, an initially retracted state, a
completely retracted state, an initially advanced state, and a
completely advanced state of the piston of the linear compressor
according to the first embodiment of the present invention.
[0056] As shown in FIGS. 4 to 9, the linear compressor according to
the first embodiment of the present invention comprises a shell 50
configured to allow introduction and discharge of working fluid, a
cylinder block 60 and a back cover 62 arranged in the shell 50, and
a compression unit P provided between the cylinder block 60 and the
back cover 62. The working-fluid, introduced into the shell 50, is
compressed by a desired compression ratio while passing through the
compression unit P, thereby being discharged in a high-pressure
state.
[0057] A fluid suction pipe 52 is connected to the shell 50 such
that the working-fluid is sucked into the shell 50 from an external
station. Also, a fluid discharge pipe 54 is connected to the shell
50 such that the compressed working-fluid, discharged from the
compression unit P, is guided out of the shell 50.
[0058] A damper 56 is mounted in the shell 50 to elastically
support the compression unit P.
[0059] A lubricating oil pumping device 58 is arranged in the shell
50 to pump lubricating oil G in the bottom of the shell 50 to the
compression unit P.
[0060] The back cover 62 is located closer to the fluid suction
pipe 52 than the cylinder block 60.
[0061] A muffler (not shown) is mounted to the back cover 62 to
reduce the noise of the working-fluid generated when the
working-fluid passes through the fluid suction pipe 52.
[0062] The compression unit P includes a linear motor 90 to
generate a reciprocating drive force, a cylinder 70 fixedly mounted
to the cylinder block 60, the cylinder 70 internally defining a
compression chamber 71 for the compression of the working-fluid, a
piston 80 which performs reciprocating movements in the cylinder 70
using the reciprocating drive force of the linear motor 90 to
compress the working-fluid received in the compression chamber 71
of the cylinder 70, and first and second resonance springs 110 and
112 to allow vibrations of the piston 80 to some extent in a
reciprocating movement direction of the piston 80 when the piston
80 reciprocally moves.
[0063] The linear motor 90 is located around the cylinder 70, and
is supported by the cylinder block 60 and the back cover 62.
[0064] Considering the configuration of the linear motor 90, it
basically consists of a mover connected to the piston 80 to work in
conjunction with the piston 80, and a stator adapted to
electromagnetically interact with the mover for inducing
reciprocating movements of the mover.
[0065] The mover includes a magnet 92 arranged inside the stator in
a reciprocally movable manner, and a magnet frame 94 for the
fixation of the magnet 92, the magnet frame 94 being connected to
the piston 80 to work in conjunction with the piston 80. The magnet
frame 94 serves to transmit the reciprocating drive force of the
linear motor 90 to the piston 80.
[0066] The stator includes an outer core 95 located on the outer
circumference of the mover, a coil 96 provided in the outer core 95
to generate a magnetic field, and an inner core 97 located on the
inner circumference of the mover.
[0067] The cylinder 70 has a cylindrical structure having open
front and rear ends. The piston 80 is inserted into the open rear
end of the cylinder 70. After being compressed in the compression
chamber 71 of the cylinder 70, the working-fluid is discharged from
the open front end of the cylinder 70.
[0068] The open front end of the cylinder 70 is covered with the
discharge valve assembly 75, such that the working-fluid,
compressed in the compression chamber 71 of the cylinder 70, is
discharged into the fluid discharge pipe 54.
[0069] The discharge valve assembly 75 includes a valve cover 76
mounted to cover the open front end of the cylinder 70 while being
connected to the fluid discharge pipe 54, a discharge valve body 77
mounted to reciprocally move in front of the open front end of the
cylinder 70 within the discharge valve cover 76, and a discharge
valve spring 78 to elastically support the discharge valve body
77.
[0070] The discharge valve cover 76 may have a dual structure.
Specifically, the discharge valve cover 76 includes an inner cover
76b having a discharge hole 76a for the discharge of the
working-fluid, and an outer cover 76c located at the outside of the
inner cover 76b to surround the inner cover 76b, the outer cover
76c being connected to the fluid discharge pipe 54.
[0071] A suction path 81 is formed in the piston 80 to extend
longitudinally throughout the interior of the piston 80, such that
the suction path 81 is connected to both the fluid suction pipe 52
and the compression chamber 71 of the cylinder 70.
[0072] The suction path 81 of the piston 80 is designed to be
selectively connected to the compression chamber 71 of the cylinder
70 by the suction valve 84, which performs opening/closing
operations in accordance with the reciprocating movements of the
piston 80.
[0073] The suction valve 84 is disposed in the suction path 81 of
the piston 80 such that it is movable relative to the suction path
81. Thus, the suction valve 84 is able to perform opening/closing
operations as it moves relative to the piston 80 by an inertial
force when the piston 80 reciprocally moves.
[0074] The suction valve 84 includes a suction valve body 85
inserted in the suction path 81 of the piston 80 to move relative
to the suction path 81, the suction valve body 85 having an
elongated slot 85' extending in the reciprocating movement
direction of the piston 80, and a suction valve guide pin 86 fitted
through the piston 80 and the slot 85' of the suction valve body 85
to move relative to the slot 85' while being fixed to the piston
80.
[0075] The suction valve body 85 has a head portion 85a disposed to
protrude out of the suction path 81 of the piston 80, and a body
portion 85b inserted in the suction path 81 of the piston 80 to
move into or out of the suction path 81.
[0076] The head portion 85a of the suction valve body 85 may take
the form of a disk having a diameter smaller than a diameter of the
piston 80, but larger than a diameter of the suction path 81 of the
piston 80.
[0077] Preferably, the head portion 85a of the suction valve body
85 has a flat outer surface 85a' at an opposite side of the piston
80, to ensure even compression of the working-fluid in the
compression chamber 71 of the cylinder 70.
[0078] The body portion 85b of the suction valve body 85 may have a
D-cut shape, in order to allow the working-fluid to pass through a
space between the body portion 85b of the suction valve body 85 and
the suction path 81 of the piston 80 when the suction valve 84
moves to open the suction path 81 of the piston 80.
[0079] Specifically, the body portion 85b of the suction valve body
85 has a partially cut-away cross sectional shape of a circle
having approximately the same size as the suction path 81 of the
piston 80.
[0080] The slot 85' is formed in the body portion 85b of the
suction valve body 85, such that the suction valve guide pin 86 is
fitted through the slot 85' to move relative to the slot 85'.
[0081] In a relative movement of the suction valve guide pin 86,
one end of the slot 85' toward the head portion 85a of the suction
valve body 85 is a top dead point, and the opposite end of the slot
85' is a bottom dead point.
[0082] The suction valve guide pin 86 has a rod shape having a
diameter smaller than a length of the slot 85' of the suction valve
84.
[0083] The suction valve guide pin 86 may be arranged in the piston
80 in a radial direction of the piston 80.
[0084] With this configuration, the suction valve guide pin 86 may
be press fitted to the piston 80. The suction valve guide pin 86
may have approximately the same length as a diameter of the piston
80 such that opposite ends thereof straddle the piston 80.
[0085] The suction valve 84 is configured such that it can be
completely inserted in the piston 80 when it is desired to close
the suction path 81 of the piston 80.
[0086] Specifically, a suction valve recess 87 is formed in a front
end region of the piston 80 to be connected to the suction path 81
of the piston 80, such that the head portion 85a of the suction
valve body 85 is inserted in the suction valve recess 87.
[0087] The suction valve recess 87 may be formed in the piston 80
such that it gradually widens from the suction path 81 of the
piston 80 toward a front distal end of the piston 80.
[0088] Hereinafter, the operation of the linear compressor
according to the present invention having the above-described
configuration will be explained.
[0089] If the linear motor 90 is driven, the magnet 92 reciprocally
moves along with the magnet frame 94 via the electromagnetic
interaction of both the stator and the mover. The resulting
reciprocating drive force of the linear motor 90 is transmitted to
the piston 80 that is connected to the magnet frame 94. Thereby,
the piston 80 reciprocally moves in the cylinder 70 upon receiving
the drive force of the linear motor 90. Simultaneously, the first
and second main springs 110 and 112 are repeatedly compressed and
tensioned, causing the suction, compression, discharge of the
working-fluid to be repeated in this sequence.
[0090] Specifically, as shown in FIG. 6, if the piston 80 begins to
retract out of the cylinder 70, the suction valve 84 shows a
relative movement to the piston 80 by an inertial force, thereby
being protruded from the piston 80 into the compression chamber 71
of the cylinder 70.
[0091] Just prior to beginning the retraction of the piston 80 out
of the cylinder 70, the suction valve 84 is completely inserted in
the piston 80, and thus, the suction valve guide pin 86 of the
suction valve 84 is located at the top dead point of the slot 85'
of the suction valve 84 (See. FIG. 4).
[0092] Accordingly, if the piston 80 begins to retract out of the
cylinder 70, only the piston 80 retracts, while the suction valve
84 remains stationary. As a result, the suction valve 84 is
protruded from the piston 80.
[0093] In this case, the suction valve guide pin 86 moves along the
slot 85' of the suction valve 84 from the top dead point to the
bottom dead point of the slot 85'.
[0094] If the piston 80 continuously retracts after the suction
valve guide pin 86 reaches the bottom dead point of the slot 85' of
the suction valve 84, as shown in FIG. 7, the suction valve guide
pin 86 is retracted along with the piston 80, thereby pulling the
suction valve 84.
[0095] Thereby, the suction valve 84 is retracted along with the
piston 80 while being protruded from the piston 80.
[0096] In a state wherein the suction valve 84 is protruded from
the piston 80, the suction path 81 of the piston 80 is opened,
thereby allowing the working-fluid in the suction path 81 of the
piston 80 to be sucked into the compression chamber 71 of the
cylinder 70.
[0097] In succession, if the piston 80 advances toward the interior
of the cylinder 70, the suction valve 84 shows a relative movement
to the piston 80 by an inertial force, thereby being inserted into
the piston 80.
[0098] Specifically, if the piston 80 begins to advance into the
compression chamber 71 of the cylinder 70, as shown in FIG. 8, the
piston 80 approaches the suction valve 84, and simultaneously, the
suction valve 84 retracts toward the piston 80 by the pressure of
the working-fluid in the compression chamber 71 of the cylinder 70.
Thereby, the suction valve 84 is rapidly inserted into the piston
80, thereby closing the suction path 81 of the piston 80.
[0099] In this case, the suction valve guide pin 86 moves along the
slot 85' of the suction valve 84 from the bottom dead point to the
top dead point of the slot 85'. If the piston 80 continuously
advances after the suction valve guide pin 86 reaches the top dead
point of the slot 85' of the suction valve 84, the suction valve 84
advances along with the piston 80.
[0100] Of course, the suction valve 84 is continuously inserted in
the piston 80 by the pressure of the working-fluid in the
compression chamber 71 of the cylinder 70.
[0101] As the piston 80 advances in a state wherein the suction
path 81 of the piston 80 is closed by the suction valve 84 as
stated above, the working-fluid in the compression chamber 71 of
the cylinder 70 is compressed to a high-pressure state.
[0102] If the working-fluid in the compression chamber 71 of the
cylinder 70 is compressed to the high-pressure state, as shown in
FIG. 9, the discharge valve assembly 75 opens the compression
chamber 71 of the cylinder 70 in accordance with the force
equilibrium relationship between the pressure of the working-fluid
in the compression chamber 71 of the cylinder 70 and the discharge
valve spring 78 of the discharge valve assembly 75.
[0103] With the opening operation of the discharge valve assembly
75, the working-fluid, compressed in the compression chamber 71 of
the cylinder 70, is discharged out of the shell 50 by passing
through the discharge cover 76 and the fluid discharge pipe 54 in
this sequence.
[0104] FIGS. 10 and 11 are configuration views of important parts
of a linear compressor according to a second embodiment of the
present invention, FIG. 10 illustrating a retracted state of a
piston included in the linear compressor, and FIG. 11 illustrating
an advanced state of the piston.
[0105] As shown in FIGS. 10 and 11, the linear compressor according
to the second embodiment of the present invention employs a suction
valve 150, which includes a suction valve body 152 inserted in a
suction path 161 of a piston 160 to move relative to the suction
path 161, the suction valve body 152 having an elongated slot 150'
extending in a reciprocating movement direction of the piston 160,
and a suction valve guide pin 154 fitted through the piston 160 and
the slot 150' of the suction valve body 152 to move relative to the
slot 150' while being fixed to the piston 160.
[0106] The suction valve body 152 may be divided into a head
portion 152a disposed to protrude out of the suction path 161 of
the piston 160, and a body portion 152b configured to have a
diameter smaller than a diameter of the suction path 161 of the
piston 160 to move into or out of the suction path 161.
[0107] In the present embodiment, the suction valve 150 may further
include a guide for allowing the center of the suction valve 150 to
continuously align with the center of the piston 160 during a
relative movement between the suction valve 150 and the piston
160.
[0108] Other configurations of the second embodiment of the present
invention are identical to those of the first embodiment except for
the above-described configurations, and thus, their description
will be omitted.
[0109] Now, the opening/closing operations of the above-described
suction valve 150 of the linear compressor according to the second
embodiment of the present invention will be explained.
[0110] When the piston 160 retracts, the suction valve 150 is
protruded from the piston 160, such that the working-fluid in the
suction path 161 of the piston 160 flows through a space between
the body portion 152b of the suction valve body 152 and the suction
path 161 of the piston 160.
[0111] When the piston 160 advances, the suction valve 150 is
inserted into the piston 160, thereby closing the suction path 161
of the piston 160.
[0112] FIGS. 12 and 13 are configuration views of important parts
of a linear compressor according to a third embodiment of the
present invention, FIG. 12 illustrating a retracted state of a
piston included in the linear compressor, and FIG. 13 illustrating
an advanced state of the piston.
[0113] As shown in FIGS. 12 and 13, the linear compressor according
to the third embodiment of the present invention employs a suction
valve 200, which includes a suction valve body 202 inserted in a
suction path 211 of a piston 210 to move relative to the suction
path 211, the suction valve body 202 having an elongated slot 200'
extending in a reciprocating movement direction of the piston 210,
and a suction valve guide pin 204 fitted through the piston 210 and
the slot 200' of the suction valve body 202 to move relative to the
slot 200' while being fixed to the piston 210.
[0114] The suction valve body 202 may be divided into a head
portion 202a disposed to protrude out of the suction path 201 of
the piston 210, and a body portion 202b configured to have
approximately the same diameter as a diameter of the suction path
211 of the piston 210 to move into or out of the suction path 211,
the body portion 202b having holes 202c for the passage of the
working-fluid in the suction path 211 of the piston 210.
[0115] The body portion 202b of the suction valve body 202
internally defines a path 202d, which connects the holes 202c of
the suction valve body 202 to the suction path 211 of the piston
210.
[0116] The holes 202c of the suction valve body 202 may be
integrally formed with the slot 200' of the suction valve 200.
[0117] Other configurations of the third embodiment of the present
invention are identical to those of the first embodiment except for
the above-described configurations, and thus, their description
will be omitted.
[0118] Now, the opening/closing operations of the above-described
suction valve 200 of the linear compressor according to the third
embodiment of the present invention will be explained.
[0119] When the piston 210 retracts, the suction valve 200 is
protruded from the piston 210. Thereby, the holes 202c of the
suction valve body 202 are opened, such that the working-fluid in
the suction path 211 of the piston 210 passes through the suction
valve body 202.
[0120] When the piston 210 advances, the suction valve 200 is
inserted into the piston 210, thereby closing the suction path 211
of the piston 210.
[0121] FIGS. 14 and 15 are configuration views of important parts
of a linear compressor according to a fourth embodiment of the
present invention, FIG. 14 illustrating a retracted state of a
piston included in the linear compressor, and FIG. 15 illustrating
an advanced state of the piston.
[0122] As shown in FIGS. 14 and 15, the linear compressor according
to the fourth embodiment of the present invention includes a
suction valve 250, which includes a suction valve body 252 inserted
in a suction path 261 of a piston 260 to move relative to the
suction path 261, the suction valve body 252 having an elongated
slot 250' extending in a reciprocating movement direction of the
piston 260, and a suction valve guide pin 254 fitted through the
piston 260 and the slot 250' of the suction valve body 252 to move
relative to the suction valve body 252 while being fixed to the
piston 260.
[0123] The piston 260 is formed in a front end region thereof with
a suction valve recess 262 to be connected to the suction path 261
of the piston 260, such that a head portion 252a of the suction
valve body 252 is inserted in the suction valve recess 262.
[0124] The suction valve recess 262 of the piston 260 may have an
inclined structure on at least the region where the piston 260
comes into contact with the suction valve 250. Specifically, the
suction valve recess 262 of the piston 260 may gradually widen away
from the suction path 261 of the piston 260 toward a front distal
end of the piston 260.
[0125] The suction valve body 252 may be divided into the head
portion 252a disposed to protrude out of the suction path 261 of
the piston 260, and a body portion 252b having a D-cut shape and
adapted to move into or out of the suction path 261 of the piston
260.
[0126] Preferably, the head portion 252a of the suction valve body
252 has an inclined outer surface, such that the head portion 252a
comes into surface contact with the suction valve recess 262 of the
piston 160 when it is completely inserted into the suction valve
recess 262 of the piston 260.
[0127] Other configurations of the fourth embodiment of the present
invention are identical to those of the first embodiment except for
the above-described configurations, and thus, their description
will be omitted.
[0128] Now, the opening/closing operations of the suction valve
250, employed in the linear compressor having the above-described
configuration according to the fourth embodiment of the present
invention, will be explained.
[0129] When the piston 260 retracts, the suction valve 250 is
protruded from the piston 260, such that working-fluid in the
suction path 261 of the piston 260 passes through the suction valve
body 252.
[0130] When the piston 260 advances, the suction valve 250 is
inserted into the piston 260, thereby closing the suction path 261
of the piston 210.
[0131] As is apparent from the above description, the present
invention provides a linear compressor having the following several
advantages.
[0132] Firstly, the linear compressor of the present invention is
configured in such a fashion that a suction valve is inserted in a
suction path of a piston to move relative to the suction path,
thereby performing opening/closing operations as it moves relative
to the piston by an inertial force when the piston reciprocally
moves. The suction valve configured as stated above can always
exhibit an even opening/closing stroke, and therefore, can achieve
various advantageous effects, such as for example, improved
constant compression efficiency, little deformation or damage due
to excessive stress applied to the suction valve, an improvement in
response and durability, and minimized vibration and noise caused
by the opening/closing operations of the suction valve.
[0133] Secondly, according to the present invention, a suction
valve guide pin is provided in the piston in a radial direction of
the piston, to couple the suction valve to the piston. The use of
the suction valve guide pin has the effects of minimizing the dead
volume of a compression chamber of a cylinder, enabling the suction
valve to be easily mounted to the piston even if the piston has a
small diameter, and reducing the flow resistance of working-fluid
due to the existence of the suction valve.
[0134] Thirdly, the piston is formed with a suction valve recess
such that the suction valve is completely inserted into the piston
when the suction valve closes the suction path of the piston. This
more effectively eliminates the dead volume of the cylinder chamber
of the cylinder, and can prevent interference between the suction
valve and a discharge valve assembly.
[0135] Fourthly, by providing the suction valve with an inclined
head portion, the head portion of the suction valve can come into
surface contact with the suction valve recess of the piston,
whereby the suction valve can smoothly move into or out of the
suction valve recess of the piston, and in particular, the head
portion of the suction valve can achieve an improved stiffness.
[0136] Although the preferred embodiments of the present invention
have been disclosed for illustrative purposes, those skilled in the
art will appreciate that various modifications, additions and
substitutions are possible, without departing from the scope and
spirit of the invention as disclosed in the accompanying
claims.
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