U.S. patent application number 16/776937 was filed with the patent office on 2020-08-06 for scroll compressor.
This patent application is currently assigned to LG ELECTRONICS INC.. The applicant listed for this patent is LG ELECTRONICS INC.. Invention is credited to Yicheol CHOI, Sang Hyun JOO, Junyoung LIM, IL Young PARK.
Application Number | 20200248691 16/776937 |
Document ID | / |
Family ID | 1000004645089 |
Filed Date | 2020-08-06 |
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United States Patent
Application |
20200248691 |
Kind Code |
A1 |
PARK; IL Young ; et
al. |
August 6, 2020 |
SCROLL COMPRESSOR
Abstract
A scroll compressor includes a main housing. A driving part
configured to generate torque and a compression part driven by the
driving part are accommodated in the main housing. The compression
part includes a fixed scroll and an orbiting scroll that engages
with the fixed scroll to form a compression chamber in which a
refrigerant is compressed. The torque of the driving part is
transmitted to the compression part by a driving shaft. The driving
shaft is rotatably supported by a main bearing positioned in a low
pressure region adjacent to the driving part. Accordingly, since
the main bearing is disposed in a low pressure region, a load
applied to the main bearing may be decreased.
Inventors: |
PARK; IL Young; (Seoul,
KR) ; CHOI; Yicheol; (Seoul, KR) ; JOO; Sang
Hyun; (Seoul, KR) ; LIM; Junyoung; (Seoul,
KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LG ELECTRONICS INC. |
Seoul |
|
KR |
|
|
Assignee: |
LG ELECTRONICS INC.
Seoul
KR
|
Family ID: |
1000004645089 |
Appl. No.: |
16/776937 |
Filed: |
January 30, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04C 29/0057 20130101;
F04C 2240/56 20130101; F04C 25/00 20130101; F04C 18/0215 20130101;
F04C 27/009 20130101; F04C 2210/261 20130101 |
International
Class: |
F04C 27/00 20060101
F04C027/00; F04C 25/00 20060101 F04C025/00; F04C 29/00 20060101
F04C029/00; F04C 18/02 20060101 F04C018/02 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 1, 2019 |
KR |
10-2019-0014114 |
Claims
1. A scroll compressor comprising: a main housing including an
accommodation space and a refrigerant suction hole configured to
introduce a low pressure refrigerant into the accommodation space;
a driving part including a driving motor accommodated in the main
housing; a driving shaft coupled to the driving motor; a
compression part including a fixed scroll accommodated in the main
housing and an orbiting scroll engaged with the fixed scroll to
form a high pressure compression chamber; a main frame disposed
between the driving part and the compression part and configured to
divide an interior of the main housing into a low pressure region
and a high pressure region, the driving part being disposed in the
low pressure region and the compression part being disposed in the
high pressure region; and a main bearing attached to the main frame
in the low pressure region and configured to rotatably support the
driving shaft.
2. The scroll compressor of claim 1, further including: a medium
pressure chamber (MR) disposed between the compression part and the
main frame, such that the main bearing is disposed outside the
medium pressure chamber (MR).
3. The scroll compressor of claim 2, wherein the main frame
includes: a circular plate portion disposed between the driving
part and the compression part; and a bearing accommodation portion
disposed between the circular plate portion and the driving part
and coupled to the main bearing.
4. The scroll compressor of claim 3, wherein: the medium pressure
chamber (MR) is formed in the circular plate portion; and the
bearing accommodation portion protrudes from the circular plate
portion toward the driving part and is disposed in the low pressure
region.
5. The scroll compressor of claim 4, wherein: the bearing
accommodation portion includes a seat groove; the main bearing is
disposed in the seat groove, and a sealing member is disposed
between the medium pressure chamber (MR) and the main bearing and
configured to prevent a refrigerant from flowing between the medium
pressure chamber (MR) and the main bearing.
6. The scroll compressor of claim 5, wherein the bearing
accommodation portion includes an opening having one end connected
to the low pressure region adjacent to the driving motor and an
opposite end connected to the medium pressure chamber (MR)
separated from low pressure region by the sealing member.
7. The scroll compressor of claim 5, wherein an inner
circumferential surface of the opening includes a groove, and the
sealing member is seated in the groove.
8. The scroll compressor of claim 7, wherein the seat groove
includes a generally concave inner surface along a direction from
adjacent to the driving part towards the compression part.
9. The scroll compressor of claim 7, wherein: the groove is
disposed between the circular plate portion and the seat groove;
and a diameter of the seat groove is greater than a diameter of the
groove.
10. The scroll compressor of claim 1, wherein the main frame
includes: a circular plate portion disposed between the driving
part and the compression part; and a bearing accommodation portion
disposed between the circular plate portion and the driving
part.
11. The scroll compressor of claim 10, wherein: an interior of the
bearing accommodation portion is connected to the low pressure
region; and the main bearing is accommodated in the bearing
accommodation portion.
12. The scroll compressor of claim 11, wherein: the bearing
accommodation portion protrudes from the circular plate portion
toward the driving part; and the interior of the bearing
accommodation portion is open toward the driving part and is
connected to the low pressure region.
13. The scroll compressor of claim 12, further comprising: a medium
pressure chamber (MR) disposed between the bearing accommodation
portion and the compression part; and a sealing member disposed in
the bearing accommodation portion between the medium pressure
chamber (MR) from the low pressure region, wherein the main bearing
is disposed in a portion of the bearing accommodation portion
connected to the low pressure region.
14. The scroll compressor of claim 1, wherein: a medium pressure
chamber (MR) is formed in the main frame; and the main bearing is
disposed outside the medium pressure chamber (MR) and between the
medium pressure chamber (MR) and the driving part.
15. The scroll compressor of claim 1, wherein the refrigerant
includes a carbon dioxide refrigerant.
16. A scroll compressor comprising: a main housing; a driving motor
disposed in the main housing; a driving shaft coupled to the
driving motor; a fixed scroll attached to the main housing; an
orbiting scroll connected to the driving shaft, the orbiting scroll
forming a high pressure compression chamber with the fixed scroll;
a main frame disposed between the driving motor and the orbiting
scroll and configured to divide an interior of the main housing
into a low pressure region and a high pressure region, the main
frame including a seat groove disposed in the low pressure region;
and a main bearing disposed in the seat groove and configured to
rotatably support the driving shaft.
17. The scroll compressor of claim 16, wherein the main frame
includes: a circular plate portion; and a bearing accommodation
portion protruding from the circular plate portion towards the
driving motor.
18. The scroll compressor of claim 17, wherein the circular plate
portion includes a medium pressure chamber, the bearing
accommodation portion includes an opening extending from the seat
groove to the medium pressure chamber, and the driving shaft
extends through the opening.
19. The scroll compressor of claim 18, further including a sealing
member disposed in the bearing accommodation portion between the
seat groove and the medium pressure chamber.
20. The scroll compressor of claim 18, further including a groove
extending radially from an inner circumferential surface of the
opening into the bearing accommodation portion, the groove being
configured to receive the sealing member.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to and the benefit of
Korean Patent Application No. 2019-0014114, filed on Feb. 1, 2019,
the disclosure of which is incorporated herein by reference in its
entirety.
BACKGROUND
1. Field of the Invention
[0002] The present invention relates to a scroll compressor.
2. Discussion of Related Art
[0003] Compressors refer to apparatuses configured to compress
refrigerants. The compressors may be divided into reciprocating
type, centrifugal type, vane type, and scroll type compressors.
[0004] Among them, the scroll type compressor (hereinafter, scroll
compressor) includes a fixed scroll and an orbiting scroll. The
fixed scroll is fixed in an inner space of a sealed container and
the orbiting scroll is engaged with the fixed scroll and performs
an orbital movement. A fixed wrap protruding toward the orbiting
scroll is provided to the fixed scroll. An orbiting wrap protruding
toward the fixed scroll is provided to the orbiting scroll. A
compression chamber may be formed in the scroll compressor. The
compression chamber may be formed between the fixed wrap and the
orbiting wrap when the orbiting scroll orbits the fixed scroll, and
a refrigerant may be compressed in the compression chamber.
[0005] The scroll compressor may obtain a relatively higher
compression ratio than other kinds of compressors. In addition, the
scroll compressor has an advantage of obtaining stable torque
because refrigerant suction, refrigerant compression, and
refrigerant discharge strokes are serially performed smoothly.
Accordingly, the scroll compressor is being widely used to compress
the refrigerant in various fields.
[0006] One example of the scroll compressor is disclosed in Korean
Patent Registration No. 10-0937919 (Registration date, Jan. 13,
2010, hereinafter, numerals for illustrating a scroll compressor of
the related art are numerals disclosed in the patent which only
correspond to description for the related art).
[0007] A conventional scroll compressor includes a driving part
configured to generate torque and a scroll compression part
configured to compress a refrigerant.
[0008] The driving part includes a driving motor including a stator
210 and a rotor 220 which are provided in a housing H, and a
driving shaft 200 inserted into a central portion of the driving
motor to rotate. A main bearing 240 and a sub-bearing 250 are
installed at one side of the driving shaft 200, and a rear bearing
730 is installed at the other side thereof to rotatably support the
driving shaft 200. The main bearing 240 is inserted into a main
frame 860.
[0009] The scroll compression part includes an orbiting scroll 400
and a fixed scroll 500. The fixed scroll 500 is fixed to the main
frame 860. The fixed scroll 500 includes a scroll wrap 510 for
compressing a refrigerant. The orbiting scroll 400 is coupled to
the fixed scroll 500. The orbiting scroll 400 includes a scroll
wrap 410 coupled to the scroll wrap 510 to compress the
refrigerant. The orbiting scroll 400 rotates due to the driving
shaft 200 and compresses the refrigerant while orbiting.
[0010] A back pressure chamber BAC is formed between the orbiting
scroll 400 and the main frame 860. A back pressure is generated in
the back pressure chamber BAC so that the orbiting scroll 400 is
pressed against the fixed scroll 500.
[0011] A discharge chamber 610 to which the compressed refrigerant
is discharged is formed in the front of the housing H. In addition,
a suction chamber 710 into which the refrigerant is suctioned is
formed in the rear of the housing H. The refrigerant suctioned into
the suction chamber 710 is compressed while passing through the
driving part and the scroll compression part and is discharged to
the discharge chamber 610. Among pressures in the housing H, a
pressure in the suction chamber 710 is lowest, a pressure in the
discharge chamber 610 is highest, and a pressure in the back
pressure chamber BAC is about medium.
[0012] The above-described conventional scroll compressor is a
compressor which is applied to an air conditioning system of a
vehicle and typically uses R134a or R1234yf refrigerant (a kind of
a chemical refrigerant). Such a chemical refrigerant is a
refrigerant for generating an internal pressure ranging from a
minimum of 2 bars to a maximum of 30 bars of a scroll compressor.
In the case of the scroll compressor using a lower pressure
refrigerant, even when a main bearing is positioned at a side of a
back pressure chamber like the above-described related patent
document, a pressure applied to the main bearing is not high.
Accordingly, it may satisfy an endurance lifespan of the bearing
based on industry standards.
[0013] However, a demand for a natural refrigerant or eco-friendly
refrigerant is increasing due to a change in awareness of
environmental pollution, and various regulations on exhaust gas are
being introduced. According to such a trend, an interest in an
eco-friendly refrigerant using carbon dioxide as a refrigerant is
increasing.
[0014] In the case of carbon dioxide, carbon dioxide is used in an
environment in which a minimum pressure of 35 bars increases to a
maximum operating pressure of 130 bars in a scroll compressor.
Accordingly, components such as a main bearing are exposed to an
environment at a higher pressure than a conventional environment in
which the low pressure refrigerant is used. Accordingly, a load
applied to the main bearing increases, and thus there is a problem
in that a lifespan of the main bearing is significantly
decreased.
[0015] Accordingly, since it is difficult to satisfy a required
durability lifespan based on industry regulations, the durability
of the main bearing should be further improved. As an example,
there is a method of improving the durability of the main bearing
by increasing a size of the main bearing or performing a specific
treatment on the main bearing. However, due to interference with a
periphery thereof, it is not easy to increase the size of the main
bearing. In addition, in the case in which the specific treatment
is performed on the main bearing, a manufacturing cost is
increased.
[0016] In addition, there is a method of increasing the durability
lifespan of the main bearing by decreasing a temperature of the
periphery. However, since the main bearing is disposed in a medium
pressure chamber, it is difficult to form a cooling structure
around the main bearing.
SUMMARY OF THE INVENTION
[0017] The present invention is directed to providing a scroll
compressor with an improved structure capable of improving the
durability of a main bearing by reducing a load applied to a main
bearing in a high pressure refrigerant compressing environment.
[0018] In addition, the present invention is directed to providing
a scroll compressor with an improved structure capable of improving
the durability of a main bearing by increasing a size of the main
bearing.
[0019] In addition, the present invention is directed to providing
a scroll compressor with an improved structure capable of improving
the durability of main bearing by decreasing a temperature of a
periphery of the main bearing.
[0020] Objectives of the present invention are not limited to the
above described objectives, and other objectives, which are not
described above, and advantages of the present invention may be
more clearly understood through the following descriptions and
clearly understood through embodiments of the present invention. In
addition, it may be easily seen that the objectives and the
advantages of the present invention may be easily realized using
means and combinations thereof described in the appended
claims.
[0021] A scroll compressor according to one embodiment of the
present invention for achieving the above-described purposes
includes a main frame which divides an interior of a main housing
into a low pressure region in which a driving part is disposed and
a high pressure region in which a compression part is disposed and
a main bearing which is installed in the main frame, rotatably
supports a driving shaft, and is disposed in the low pressure
region.
[0022] Since the main bearing is disposed in the low pressure
region as described above, a load applied to the main bearing can
be decreased, and thus an increase in durability lifespan of the
main bearing can be expected.
[0023] In addition, according to another embodiment of the present
invention, a main bearing is disposed outside a medium pressure
chamber.
[0024] In addition, according to another embodiment of the present
invention, the main bearing is disposed in a bearing accommodation
portion, and a sealing member is disposed between the main bearing
and the medium pressure chamber to block the medium pressure
chamber from a low pressure region.
[0025] In addition, according to another embodiment of the present
invention, the main bearing is disposed in the bearing
accommodation portion and is disposed in a space blocked from the
medium pressure chamber by a sealing member.
[0026] In addition, according to another embodiment of the present
invention, the main bearing is disposed outside the medium pressure
chamber and is disposed in a space between the medium pressure
chamber and a driving part.
[0027] Accordingly, the main bearing may be disposed in the low
pressure region having a relatively wider space than a region of
the medium pressure chamber. Therefore, since a size of the main
bearing can be increased easily, the main bearing having high
durability even in a high pressure environment can be provided.
[0028] According to an aspect of the present invention, there is
provided a scroll compressor including a main housing forming an
accommodation space and including a refrigerant suction hole
through which a low pressure refrigerant is introduced, a driving
part including a driving motor accommodated in the main housing and
configured to generate torque and a driving shaft coupled to the
driving motor to rotate, a compression part including a fixed
scroll accommodated in the main housing and an orbiting scroll
engaged with the fixed scroll to form a high pressure compression
chamber, a main frame which is disposed between the driving part
and the compression part and divides an interior of the main
housing into a low pressure region in which the driving part is
disposed and a high pressure region in which the compression part
is disposed, and a main bearing which is installed in the main
frame, rotatably supports the driving shaft, and is disposed in the
low pressure region.
[0029] A medium pressure chamber may be disposed between the
compression part and the main frame, and the main bearing may be
disposed outside the medium pressure chamber.
[0030] The main frame may include a circular plate portion disposed
between the driving part and the compression part, and a bearing
accommodation portion disposed between the circular plate portion
and the driving part and coupled to the main bearing.
[0031] The medium pressure chamber may be formed in the circular
plate portion, and the bearing accommodation portion may protrude
from the circular plate portion toward the driving part and may be
disposed in the low pressure region.
[0032] An opening connected to the medium pressure chamber may be
formed in the bearing accommodation portion, the main bearing may
be disposed in the opening of the bearing accommodation portion,
and a sealing member configured to prevent a refrigerant from
moving between the medium pressure chamber and the main bearing may
be formed between the medium pressure chamber and the main
bearing.
[0033] The sealing member may be disposed in the opening of the
bearing accommodation portion to seal an inner space of the bearing
accommodation portion, and an inner space, which is close to the
medium pressure chamber with respect to the sealing member, of the
bearing accommodation portion may be connected to the medium
pressure chamber and an inner space, which is close to the driving
motor with respect to the sealing member, of the bearing
accommodation portion may be connected to the low pressure
region.
[0034] A seat groove in which the main bearing is seated and a
groove in which the sealing member is seated may be formed in an
inner circumferential surface of the bearing accommodation portion
in the main housing.
[0035] The seat groove may be concavely formed in a direction from
one side, which faces the driving part, of the bearing
accommodation portion toward the compression part.
[0036] The seat groove may be concavely formed in the bearing
accommodation portion to be open toward the driving part, the
groove may be disposed between the circular plate portion and the
seat groove, and a diameter of the seat groove may be greater than
a diameter of the groove.
[0037] The main frame may include a circular plate portion disposed
between the driving part and the compression part, and a bearing
accommodation portion disposed between the circular plate portion
and the driving part and coupled to the main bearing.
[0038] In addition, an interior of the bearing accommodation
portion may be connected to the low pressure region, and the main
bearing may be accommodated in the bearing accommodation
portion.
[0039] The bearing accommodation portion may protrude from the
circular plate portion toward the driving part, and the interior of
the bearing accommodation portion may be open toward the driving
part and may be connected to the low pressure region.
[0040] The scroll compressor may further include a medium pressure
chamber disposed between the bearing accommodation portion and the
compression part and a sealing member disposed in the bearing
accommodation portion to block the medium pressure chamber from the
low pressure region, wherein the main bearing may be disposed in a
space blocked from the medium pressure chamber.
[0041] A medium pressure chamber may be formed in the main frame,
and the main bearing may be disposed outside the medium pressure
chamber and disposed in a space between the medium pressure chamber
and the driving part.
[0042] The refrigerant may be a carbon dioxide refrigerant.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] The above and other objects, features and advantages of the
present invention will become more apparent to those of ordinary
skill in the art by describing exemplary embodiments thereof in
detail with reference to the accompanying drawings, in which:
[0044] FIG. 1 is an exploded perspective view illustrating a scroll
compressor according to one embodiment of the present
invention;
[0045] FIG. 2 is a cross-sectional view illustrating the scroll
compressor according to FIG. 1;
[0046] FIG. 3 is an enlarged cross-sectional view illustrating an
installation state of a main bearing according to FIG. 2;
[0047] FIG. 4 is a schematic view illustrating a main bearing and a
sealing position of a conventional scroll compressor; and
[0048] FIG. 5 is a schematic view illustrating the main bearing and
a sealing position of the scroll compressor of the present
invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0049] The above-described purposes, features, and advantages will
be described in detail with reference to the accompanying drawings,
and thus the technical spirit of the present invention may be
easily executed by those skilled in the art. When it is determined
that the detailed descriptions of related well-known technologies
unnecessarily obscure the gist of the invention, the detailed
descriptions will be omitted. Hereinafter, exemplary embodiments of
the present invention will be described in detail with reference to
the accompanying drawings. The same or similar elements are denoted
by the same reference numerals in the drawings throughout this
specification.
[0050] Although terms such as first, second, or the like may be
used for describing various elements, the elements are not limited
to the terms. The terms are only used to distinguish one element
from another element, and unless otherwise specifically described,
a first element may also be a second element.
[0051] Hereinafter, a case in which an arbitrary element is
disposed "above (or under)" or "on (or below)" an element may
include a case in which the arbitrary element is disposed to be in
contact with an upper (or lower) surface of the element, or a case
in which still another element may be interposed between the
element and the arbitrary element disposed above (or under) the
element.
[0052] It should be understood that, when an element is referred to
as being "connected or coupled" to another element, the element may
be directly connected or coupled to another element, still another
element may be interposed therebetween, or the elements may be
connected or coupled through still another element.
[0053] Throughout the specification, unless specifically described
otherwise, the number of elements may be one or a plurality.
[0054] The singular forms "a," "an," and "the" used in the present
specification are intended to include the plural forms as well,
unless the context clearly indicates otherwise. It should be
interpreted that the terms "comprises," "comprising," "includes,"
and/or "including," when used herein, do not necessarily include
all components or various operations stated in the specification
and may not include some components and operations therein or may
further include additional components and operations.
[0055] Throughout the specification, unless otherwise specifically
described, "A and/or B" refers to "A, B, or A and B," and "C to D"
refers to "more than or equal to C and less than or equal to D"
[0056] FIG. 1 is an exploded perspective view illustrating a scroll
compressor according to one embodiment of the present invention.
FIG. 2 is a cross-sectional view illustrating the scroll compressor
according to FIG. 1. FIG. 3 is an enlarged cross-sectional view
illustrating an installation state of a main bearing according to
FIG. 2.
[0057] As illustrated in FIGS. 1 and 2, a scroll compressor 10
according to one embodiment of the present invention includes a
main housing 110 forming an accommodation space, and a front head
130 and a rear head 150 coupled to the front and the rear of the
main housing 110 to cover the accommodation space. An inverter
assembly 170 is coupled to the front of the front head 130. A
driving part 300 and a compression part 500 are accommodated in the
accommodation space (hereinafter, a direction toward the front head
is defined as a forward direction and a direction toward the rear
head is defined as a rearward direction. Accordingly, a surface
positioned toward the front head of each component is a front
surface thereof, and a surface positioned toward the rear head of
each component is a rear surface thereof).
[0058] The main housing 110 has an exterior having a substantially
cylindrical shape. In addition, the main housing 110 has a shape in
which both ends are open in a longitudinal direction. The front
head 130 and the rear head 150 are coupled to the both open ends.
The front head 130 and rear head 150 have substantially circular
plate shapes corresponding to shapes of end portions of the main
housing 110.
[0059] A refrigerant suction hole (not shown) configured to suction
a refrigerant and a refrigerant suction chamber (not shown) are
formed at one front side of the main housing 110. A refrigerant
discharge hole 112, through which a refrigerant compressed by the
compression part 500 is discharged, and a refrigerant discharge
chamber 114 are formed between the rear of the main housing 110 and
the rear head 150. An oil storage portion 152 is formed in the rear
head 150. An oil separator 154 configured to separate oil from the
discharged refrigerant is installed in the oil storage portion
152.
[0060] The low temperature and low pressure refrigerant introduced
through the refrigerant suction hole cools the driving part 300
while passing through a refrigerant suction chamber and moving from
a front portion in the main housing toward a rear portion therein
and is introduced into the compression part 500. The refrigerant
introduced into the compression part 500 is compressed into a high
temperature and high pressure state and discharged to the
refrigerant discharge chamber 114 through the refrigerant discharge
hole 112. The discharged refrigerant is separated from the oil in
the oil separator 154 and discharged to the outside of the rear
head 150. The oil separated in the oil separator 154 is supplied to
a medium pressure chamber MR, which will be described below, from
the oil storage portion 152 through an oil path P. The oil supplied
to the medium pressure chamber MR lubricates portions of the
compression part 500.
[0061] Among the above-described components included in the scroll
compressor 100, the driving part 300 and the compression part 500
will be described in detail.
[0062] As illustrated in FIGS. 1 to 3, the driving part 300
includes a driving motor 310 configured to generate torque and a
driving shaft 330 rotated by the driving motor 310.
[0063] The driving motor 310 includes a stator 312 fixedly
installed in the main housing 110 and a rotor 314 which is inserted
into the stator 312 and is rotated. The stator 312 may be formed to
have a cylindrical shape. The stator 312 includes a plurality of
slots around which coils are wound. The rotor 314 is rotated due to
an electromotive force of a magnetic field generated by the stator
312. The driving shaft 330 is inserted into and passes through an
inside of the rotor 314. The driving shaft 330 is rotated due to
rotation of the rotor 314.
[0064] One side of the driving shaft 330 is fixed to the rotor 314,
and the other side of the driving shaft 330 extends toward the
compression part 500. One side of the driving shaft 330 may be
rotatably supported by a front bearing 350. The other side of the
driving shaft 330 may be rotatably supported by a main bearing
370.
[0065] The front bearing 350 is coupled to the front head 130 and
rotatably supports the driving shaft 330. The main bearing 370 is
coupled to the main housing 110 of the compression part 500, which
will be described below, and rotatably supports the driving shaft
330 (the main bearing will be described below).
[0066] The compression part 500 may include a fixed scroll 510
fixed to the main housing 110 and an orbiting scroll 520 coupled to
perform an orbital movement on the fixed scroll 510. In addition,
the compression part 500 may further include a plurality of pins
530 and rings 540 configured to restrict rotation of the orbiting
scroll 520. In addition, the compression part 500 may further
include an eccentric bush 550, which causes the orbiting scroll 520
to orbit, and a sub-bearing 560 which rotatably supports the
eccentric bush 550. In addition, the compression part 500 may
further include a main frame 580 disposed between and coupled to
the orbiting scroll 520 and the driving part 300 to support the
driving shaft 330.
[0067] The fixed scroll 510 may be disposed close to the rear head
150. A rear surface of the fixed scroll 510 may be coupled to the
rear head 150. The fixed scroll 510 may be formed to have a
cylindrical shape in which a side toward the front head 130 is
open. The fixed scroll 510 may include a fixed wrap 512 formed to
protrude toward the front head 130.
[0068] The fixed wrap 512 may protrude from a front surface of the
fixed scroll 510 to have a vortex shape. The fixed wrap 512 is
coupled to the orbiting scroll 520 to form a compression chamber
CR. An orbiting wrap 522 of the orbiting scroll 520, which will be
described below, may be engaged with and coupled to the fixed wrap
512.
[0069] The orbiting scroll 520 may be formed to have a size less
than a size of the fixed scroll 510 and coupled to the fixed scroll
510. The orbiting scroll 520 may be inserted into the fixed scroll
510 through the open side of the fixed scroll 510 to be coupled to
the fixed scroll 510. The orbiting scroll 520 may be formed to have
a circular plate shape having a predetermined thickness. The
orbiting scroll 520 may include the orbiting wrap 522 protruding
from a rear surface of the orbiting scroll 520, which faces the
fixed wrap 512, of the orbiting scroll 520. A coupling portion 524
is formed to protrude from a front surface of the orbiting scroll
520, and the sub-bearing 560 may be coupled to the coupling portion
524. In addition, a plurality of pin and ring grooves 526 may be
formed in the front surface of the orbiting scroll 520. The pins
530 and the rings 540 may be inserted into the pin and ring grooves
526.
[0070] The orbiting wrap 522 may protrude from the rear surface of
the orbiting scroll 520 to have a vortex shape. The orbiting wrap
522 may be coupled to the fixed wrap 512 to form the compression
chamber CR. The fixed wrap 512 may be engaged with and coupled to
the orbiting wrap 522, and the compression chamber CR may be formed
between the fixed wrap 512 and the orbiting wrap 522.
[0071] The bearing coupling portion 524 may protrude from a center
of the front surface of the orbiting scroll 520. The bearing
coupling portion 524 protrudes to have a cylindrical shape such
that the sub-bearing 560 is inserted into the bearing coupling
portion 524. The sub-bearing 560 may be inserted into and supported
by the bearing coupling portion 524. An opening may be formed in
the sub-bearing 560. The eccentric bush 550 may be inserted into
the opening so that the eccentric bush 550 may be rotatably
supported by the sub-bearing 560.
[0072] The plurality of pin and ring grooves 526 may be disposed in
the front surface of the orbiting scroll 520 in a circumferential
direction. The plurality of rings 540 may be inserted into the pin
and ring grooves 526. The cylindrical pins 530 may be inserted into
the rings 540. The pins 530 may be coupled to the main frame 580.
The pins 530 come into contact with the rings 540 to restrict
movement of the rings 540.
[0073] The eccentric bush 550 may be inserted into the front of the
orbiting scroll 520. The eccentric bush 550 may be rotatably
supported by the sub-bearing 560. The eccentric bush 550 may be
formed to have a shape in which a weight 552 having an arc shape is
connected to one side of a cylinder. Accordingly, the eccentric
bush 550 has an eccentric rotating weight. The driving shaft 330
may be coupled to a central portion of the eccentric bush 550, and
the sub-bearing 560 may be coupled to an outer circumferential
surface of the eccentric bush 550. In this case, the outer
circumferential surface of the eccentric bush 550 may be in contact
with an inner circumferential surface of the sub-bearing 560. When
the driving shaft 330 rotates, the eccentric bush 550 rotates
together with the driving shaft 330. In this case, the eccentric
bush 550 rotates in a state in which a center of gravity is
eccentrically applied toward the weight 552. The orbiting scroll
520 may be prevented from self-orbiting by the eccentric bush 550,
the pins 530, and the rings 540, and the orbiting scroll 520 may
orbit the fixed scroll 510.
[0074] The main frame 580 may be disposed in front of the orbiting
scroll 520 and coupled to an inner circumferential surface of the
main housing 110. To this end, a circular plate portion 582 may be
formed at one side, which faces the orbiting scroll 520, of the
main frame 580. The circular plate portion 582 may be formed to
have a circular plate shape having an outer diameter corresponding
to an inner diameter of the main housing 110. The above-described
pins 530 may be fixed to a rear surface of the circular plate
portion 582. In addition, the driving shaft 330 passes through the
circular plate portion 582 by passing through a center of the
circular plate portion 582. In addition, the circular plate portion
582 should not interfere with the eccentric bush 550 when the
eccentric bush 550 rotates. Accordingly, a space should be formed
at a central portion of the circular plate portion 582 so as to not
hinder the rotation of the eccentric bush 550. The eccentric bush
550 rotates in the space formed as described above, and a
refrigerant may be introduced into the space. The space is defined
as the medium pressure chamber MR.
[0075] A refrigerant introduced into the main housing 110 is in a
low temperature and low pressure state. When the refrigerant passes
through the driving part 300 and cools the driving part 300, the
refrigerant is heated by heat of the driving part 300 so that a
temperature and a pressure of the refrigerant are increased. In
this state, the refrigerant introduced into the medium pressure
chamber MR is in a medium temperature and medium pressure state.
When the medium temperature and medium pressure refrigerant is
compressed in the compression chamber CR, the refrigerant is in a
high temperature and high pressure state and is discharged to the
refrigerant discharge chamber 114. In addition, due to a pressure
generated in the medium pressure chamber MR, the orbiting scroll
520 may be pressed against the fixed scroll 510 to compress the
refrigerant.
[0076] In addition, as is well known, some of the refrigerant being
compressed in the compression chamber CR is introduced into the
medium pressure chamber MR, and a medium pressure may be generated
in the medium pressure chamber MR due to the refrigerant introduced
into the medium pressure chamber MR as described above.
[0077] To this end, a back pressure hole (not shown) may be formed
in the orbiting scroll 520. The back pressure hole may be formed to
pass through the orbiting scroll 520, one side of the back pressure
hole may be open toward the compression chamber.
[0078] CR, and the other side of the back pressure hole may be open
toward the medium pressure chamber MR. That is, the back pressure
hole may form a path disposed between the compression chamber CR
and the medium pressure chamber MR to connect them.
[0079] Some of the refrigerant compressed to have an approximately
medium pressure in the compression chamber CR may be introduced
into the medium pressure chamber MR through the back pressure hole.
The refrigerant introduced into the medium pressure chamber MR as
described above may generate a medium pressure in the medium
pressure chamber MR. Due to the pressure generated in the medium
pressure chamber MR as described above, a contact degree between
the orbiting scroll 520 and the fixed scroll 510 may be
improved.
[0080] In this case, a low temperature, a medium temperature, a
high temperature, a low pressure, a medium pressure, and a high
pressure are terms of relative concepts and are for describing
temperatures and pressures in the scroll compressor 100 as
relatively low, medium, and high temperatures and pressures.
[0081] In the scroll compressor 100 of the present invention, a
portion in which the driving part 300 is positioned may be defined
as a low pressure region. In addition, a portion between the main
frame 580 and the orbiting scroll 520 may be defined as a medium
pressure region, and a portion between the orbiting scroll 520 and
the rear head 150 may be defined as a high pressure region.
[0082] In addition, the driving shaft 330 may pass through the main
frame 580. The main bearing 370 supporting the driving shaft 330 is
coupled to the main frame 580. A bearing accommodation portion 584
may be provided in the main frame 580. The bearing accommodation
portion 584 may protrude from a front surface of the circular plate
portion 582 toward the front head 130 to have a cylindrical shape.
The main bearing 370 may be inserted into the bearing accommodation
portion 584 and coupled to the main frame 580. The bearing
accommodation portion 584 is separated from the medium pressure
chamber MR by the sealing member 570. Accordingly, the bearing
accommodation portion 584 is positioned in the low pressure
region.
[0083] The sealing member 570, like the main bearing 370, may be
disposed inside the main frame 580. Among the sealing member 570
and the main bearing 370, the sealing member 570 may be disposed at
a position closer to the orbiting scroll 520. That is, the sealing
member 570 may be disposed between the main bearing 370 and the
orbiting scroll 520. As an example, the sealing member 570 may
include a shaft seal, a snap ring, and the like. A groove 586 (see
FIG. 5) may be formed inside the main frame 580. At least a part of
the sealing member 570 may be inserted into the groove 586 so that
the sealing member 570 may be inserted into the groove 586. Since
the sealing member 570 is inserted into the groove 586, the sealing
member 570 may be installed inside the main frame 580. The groove
586 may be formed to have a size less than a size of a seat groove
584a in which the main bearing 370 is seated.
[0084] The bearing accommodation portion 584 may be formed to have
a cylindrical shape. An opening is formed in the bearing
accommodation portion 584, and the driving shaft 330 passes through
and is inserted into the main frame 580 through the opening. The
seat groove 584a may be provided around the opening. The seat
groove 584a may be formed to have a shape in which an inner
circumferential surface of the bearing accommodation portion 584 is
concavely machined. The main bearing 370 may be seated in the seat
groove 584a. That is, the main bearing 370 may be seated in the
seat groove 584a so that the main bearing 370 may be installed in
the bearing accommodation portion 584, and the driving shaft 330
may be coupled to the main bearing 370 and may pass through the
bearing accommodation portion 584. The driving shaft 330 may be
rotatably supported by the main bearing 370.
[0085] One of important features of the scroll compressor is that
the main bearing 370 is disposed in the low pressure region as
illustrated in FIG. 3. As an example, the main bearing 370 may be
disposed at a position close to the driving part 300. The main
bearing 370 may rotatably support the driving shaft 330 in the low
pressure region.
[0086] As regulations for reducing air pollutants are gradually
tightened, carbon dioxide is attracting attention as an
eco-friendly refrigerant to replace R134a or R1234yf which is a
chemical refrigerant. In the case of the chemical refrigerant, the
chemical refrigerant is used in a compressor at a pressure ranging
from 2 to 30 bars.
[0087] However, in the case of a carbon dioxide refrigerant (R744
refrigerant), a high pressure operating environment is needed to
maintain a stable refrigerant state of the carbon dioxide.
Generally, the carbon dioxide refrigerant is used at a pressure
ranging from 35 to 130 bars in a compressor. In a general scroll
compressor, a suction pressure of a refrigerant is about 30 bars,
and an internal pressure of a driving part which is a low pressure
region is about 35 bars. A pressure in a medium pressure chamber
ranges from about 70 to 80 bars, and a temperature of the medium
pressure chamber is about 100.degree. C. Internal pressures of the
compression chamber CR and the refrigerant discharge chamber 114
which are high pressure regions are maximum 130 bars.
[0088] A compressor applied to a vehicle should satisfy a condition
of a "required durability lifespan" required for each component. A
method of satisfying a required durability lifespan of the main
bearing 370 may include a method of improving the durability of the
main bearing 370 itself or a method of reducing a load applied to
the main bearing 370.
[0089] The method of improving the durability of the main bearing
370 itself may include a method of increasing a size of the main
bearing 370 or a method of performing a specific treatment, such as
heat treatment, on the main bearing 370. In addition, the method of
improving the durability of the main bearing 370 may also include a
method of forming the main bearing 370 with a specific
material.
[0090] However, when the main bearing 370 is formed of the specific
material, a manufacturing cost of the main bearing 370 should be
increased. Accordingly, the main bearing 370 is generally formed of
a steel material. The steel material is sensitive to a temperature.
Accordingly, in the case in which the main bearing 370 is formed of
the steel material, there is a problem in that a durability
lifespan is decreased when a temperature around the main bearing
370 is high.
[0091] In addition, since design requirements such as interference
with nearby components therearound and a size limitation of the
compressor should be satisfied, it is also difficult to arbitrarily
increase the size of the main bearing 370.
[0092] Meanwhile, the method of reducing the load applied to the
main bearing 370 may include a method of reducing a load applied to
the main bearing 370 itself or a method of indirectly reducing a
load of the main bearing 370 by decreasing a temperature around the
main bearing 370. Since a durability lifespan of the main bearing
370 is decreased when a temperature of the main bearing 370 is
high, when the temperature of the main bearing 370 is decreased,
the durability lifespan of the main bearing 370 can be
increased.
[0093] By considering such a point, in the present embodiment, the
main bearing 370 is disposed in a low temperature and low pressure
region. Since the main bearing 370 is disposed in the low
temperature and low pressure region as described above, a pressure
and a temperature applied to the main bearing 370 may be decreased.
Referring to the related patent, a main bearing 240 is
conventionally disposed in a back pressure chamber BAC which is a
medium pressure region. Accordingly, in a case in which the same
structure is applied to a compressor using a carbon dioxide
refrigerant, since the main bearing 240 is exposed at a very high
pressure and a very high temperature, it is difficult to satisfy a
required durability lifespan of the main bearing 240.
[0094] In comparison thereto, in the present embodiment, the main
bearing 370 is disposed in the low temperature and low pressure
region. Accordingly, since the main bearing 370 is exposed at a
pressure and a temperature which are much lower than those of the
medium pressure chamber MR, and temperatures of the main bearing
370 and peripherals are decreased, a durability lifespan of the
main bearing 370 can be increased. In addition, in the present
embodiment, the main bearing 370 may not be disposed in the medium
pressure chamber MR in the main frame 580 but may be disposed in a
space which is the same as a space in which the driving part 300 is
disposed. The space in which the driving part 300 is disposed, more
specifically, a space between the medium pressure chamber MR and
the driving part 300 may be relatively wider than the medium
pressure chamber MR. Accordingly, since the size of the main
bearing 370 may be increased as much as a space which is more
widely secured than the medium pressure chamber MR, the method of
increasing the size of the main bearing 370 may effectively
increase the durability lifespan of the main bearing 370.
[0095] For example, the main bearing 370 should satisfy a required
durability lifespan of 700 hours based on the Deutsches Institut
fur Normung (DIN) standard which is a German industry standard.
[0096] As a result of a predictive modeling of a durability
lifespan of the main bearing 370, a durability lifespan of the main
bearing 370 is only about 270 hours when a temperature around the
main bearing 370 is 100.degree. C. However, when the temperature
around the main bearing 370 is decreased, a durability lifespan of
the main bearing 370 is increased by about 60 hours when the
temperature around the main bearing 370 is decreased by 10.degree.
C. Accordingly, when the temperature around the main bearing 370 is
100.degree. C., the temperature around the main bearing 370 should
be decreased to under 30.degree. C. to satisfy the DIN
standard.
[0097] In addition, when a diameter of the main bearing 370 is
increased, a durability lifespan of the main bearing 370 may be
increased as much as the increase. For example, when the diameter
of the main bearing 370 is increased from 47 phi to 52 phi, in the
condition of a temperature of 100.degree. C., the durability
lifespan of the main bearing 370 may be increased two or more times
from 270 hours to 611 hours.
[0098] Accordingly, when the size of the main bearing 370 is
increased and a temperature around the main bearing 370 is
decreased, the DIN standard may be more effectively satisfied. For
example, when the size of the main bearing 370 is increased by 5
phi and the temperature around the main bearing 370 is decreased by
20.degree. C., a durability lifespan of the main bearing 370 is
increased to 720 hours or more so that a required durability
lifespan required on the DIN standard may be satisfied. In this
case, when the temperature around the main bearing 370 is further
decreased, the durability lifespan of the main bearing 370 is
significantly increased so that a required lifespan greater than or
equal to a required durability lifespan required in the DIN
standard may be obtained. In the scroll compressor 100 of the
present embodiment, a temperature of the low pressure region in
which the main compressor 100 is disposed ranges from about 25 to
30.degree. C.
[0099] A layout of the main bearing 370 according to the present
embodiment may provide an effect superior to a conventional
structure in terms of machinability of the scroll compressor
100.
[0100] FIG. 4 is a schematic view illustrating a main bearing and a
sealing position of a conventional scroll compressor. FIG. 5 is a
schematic view illustrating the main bearing and a sealing position
of the scroll compressor of the present invention.
[0101] As illustrated in FIG. 4, in a conventional scroll
compressor 100', a main bearing 370' is disposed in a main frame
580'. The shaft seal 570' is inserted into the main frame 580'
spaced apart from the main bearing 370'. The shaft seal 570'
prevents a refrigerant introduced into a medium pressure chamber
MR', in which the main bearing 370' is installed, from flowing back
to a low pressure region at which a driving part 300' is
positioned. Accordingly, the shaft seal 570' is disposed between
the main bearing 370' and the driving part 300' to be closer to the
driving part 300' than to the main bearing 370'.
[0102] A seat groove 584a' corresponding to a size and a shape of
the main bearing 370' should be formed in a part of the main frame
580', more specifically, in a part into which the main bearing 370'
is inserted. The seat groove 584a' may be formed in an inner
circumferential surface of the main frame 580'. In addition, a
groove 586' corresponding to a size and a shape of the shaft seal
570' should also be formed in the inner circumferential surface of
the main frame 580'. In this case, the seat groove 584a' is
disposed at a side further away from the driving part 300' than
from the groove 586', in other words, is disposed at a side close
to a rear side of the main frame 580'. However, since the size of
the main bearing 370' is greater than the size of the shaft seal
570', when the seat groove 584a' is disposed closer to the rear
side of the main frame 580' than the groove 586', a degree of
difficulty of a process of machining the seat groove 584a'
performed from a front side of the main frame 580' is increased.
Accordingly, concerns about an increase in tolerance of the seat
groove 584' are high.
[0103] In addition, since the main frame 580' is formed of an
aluminum material and the main bearing 370' is formed of a steel
material, a coefficient of thermal expansion of the main frame 580'
is different from a coefficient of thermal expansion of the main
bearing 370'. That is, thermal expansion of the main frame 580'
that occurs is greater than thermal expansion of the main bearing
370'. Accordingly, when a tolerance of the seat groove 584a' is
greater than an allowable value, the main bearing 370' may be
separated from the seat groove 584a'. Accordingly, a stacking or
cogging process machining is additionally required to prevent the
main bearing 370' from being separated from the seat groove
584a'.
[0104] In comparison thereto, in the present embodiment, as
illustrated in FIG. 5, the main bearing 370 is disposed at a side
closer to the driving part 300 than the sealing member 570, that
is, in other words, is disposed at a side close to the front of the
main frame 580. In addition, the sealing member 570 is disposed at
a side closer to the rear of the main frame 580 than the main
bearing 370. As the result, the above-described problems can be
removed.
[0105] That is, when the groove 586 for the sealing member 570 is
first machined in the rear of the main frame 580, and the seat
groove 584a for the main bearing 370 is machined in the front of
the main frame 580, machinability for the seat groove 584a and the
groove 586 may be improved. Since the groove 586 is a very small
groove when compared to the seat groove 584a, even when the groove
586 is positioned at the rear side of the main frame 580, the
groove 586 can be easily machined from a front side of the main
frame 580. Then, when the seat groove 584a is machined in the front
side of the main frame 580, the seat groove 584a can be easily
machined.
[0106] In addition, since the main bearing 370 is disposed in the
low temperature and low pressure region which is not the medium
pressure chamber MR, a possibility that a problem occurs due to
thermal expansion of the main housing 110 is significantly
decreased. Accordingly, a possibility that the main bearing 370 is
separated from the seat groove 584a is also significantly
decreased. Accordingly, since an additional process such as a
stacking or cogging process is not necessary, effects in which a
period of a manufacturing process is decreased and an additional
cost is saved can be provided.
[0107] In the above-described embodiment, the structure in which
the main frame is formed to be separated from the main housing so
as to support the orbiting scroll has been described. However, the
installation structure of the main bearing can be similarly applied
to a scroll compressor in which a main frame and a main housing are
integrally formed.
[0108] As described above, in a scroll compressor according to the
present invention, since an installation position of a main bearing
is moved to a low pressure region so that the main bearing can
operate in a low pressure environment, there are effects in that a
load of the main bearing is decreased and durability is
improved.
[0109] In addition, in the scroll compressor according to the
present invention, since the installation position of the main
bearing is moved to the low pressure region so that an installation
space is relatively increased, a size of the main bearing can be
increased, and thus there is an effect in that the durability of
the main bearing itself is improved.
[0110] In addition, in the scroll compressor according to the
present invention, since the installation position of the main
bearing is moved to the low pressure region so that the main
bearing operates at a relatively low temperature, there is an
effect in that the durability of the main bearing is improved due
to a decrease in temperature.
[0111] Specific effects and the above-described effects of the
present invention have been described while the specific
embodiments for realizing the present invention are described in
the detailed description.
[0112] Although the present invention has been described with
reference to the accompanying drawings as described above, the
present invention is not limited by the embodiments and drawings
illustrated in the present specification, and it is clear that the
present invention is variously modified by those skilled in the art
within a range of the technical spirit of the present invention. In
addition, while the embodiments of the present invention have been
described, although the operational effects according to the
structure of the present invention have not been clearly described,
predictable effects according to the corresponding structure should
also be recognized.
* * * * *