U.S. patent application number 16/519276 was filed with the patent office on 2020-01-30 for motor-operated 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 Soonyong CHOI, Jongtae HER, Kitae JANG, Jehoon KIM.
Application Number | 20200032798 16/519276 |
Document ID | / |
Family ID | 67439011 |
Filed Date | 2020-01-30 |
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United States Patent
Application |
20200032798 |
Kind Code |
A1 |
HER; Jongtae ; et
al. |
January 30, 2020 |
MOTOR-OPERATED COMPRESSOR
Abstract
A motor-operated compressor includes: a fixed scroll; an
orbiting scroll engaged with the fixed scroll to perform an
orbiting motion and forming a pair of compression chambers together
with the fixed scroll during the orbiting motion; a frame provided
opposite to the fixed scroll with the orbiting scroll interposed
therebetween, and forming a back pressure chamber so as to axially
support the orbiting scroll; and a rotation shaft coupled to the
frame and the orbiting scroll in a penetrating manner. The rotation
shaft is supported by the frame in a first axial direction and
rotatably coupled to the fixed scroll, and an elastic member is
disposed between the fixed scroll and the rotation shaft to support
the rotation shaft in a second axial direction opposite to the
first axial direction with respect to the first scroll.
Inventors: |
HER; Jongtae; (Seoul,
KR) ; KIM; Jehoon; (Seoul, KR) ; JANG;
Kitae; (Seoul, KR) ; CHOI; Soonyong; (Seoul,
KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LG Electronics Inc. |
Seoul |
|
KR |
|
|
Assignee: |
LG Electronics Inc.
Seoul
KR
|
Family ID: |
67439011 |
Appl. No.: |
16/519276 |
Filed: |
July 23, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04C 2240/40 20130101;
F04C 29/0021 20130101; F04C 27/005 20130101; F04C 2240/30 20130101;
F04C 18/0269 20130101; F04C 18/0215 20130101 |
International
Class: |
F04C 18/02 20060101
F04C018/02; F04C 27/00 20060101 F04C027/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 26, 2018 |
KR |
10-2018-0087383 |
Claims
1. A motor-operated compressor, comprising: a fixed scroll; an
orbiting scroll engaged with the fixed scroll and configured to
perform an orbiting motion relative to the fixed scroll, and the
orbiting scroll and the fixed scroll forming a pair of compression
chambers therebetween during the orbiting motion; a frame disposed
opposite to the fixed scroll with the orbiting scroll interposed
between the frame and the fixed scroll, a back pressure chamber
being formed between the frame and the orbiting scroll, and the
back pressure chamber being configured to axially support the
orbiting scroll; a rotation shaft coupled to the frame and the
orbiting scroll and penetrating through the frame and the orbiting
scroll, and the rotation shaft being supported on the frame in a
first axial direction and rotatably coupled to the fixed scroll;
and an elastic member disposed between the fixed scroll and the
rotation shaft, the elastic member being configured to support the
rotation shaft in a second axial direction opposite to the first
axial direction with respect to the fixed scroll.
2. The motor-operated compressor of claim 1, wherein: the fixed
scroll includes a rotation shaft receiving portion configured to
accommodate at least a part of the rotation shaft, and the elastic
member is contained in the rotation shaft receiving portion.
3. The motor-operated compressor of claim 2, wherein: the rotation
shaft receiving portion includes a support surface facing an end
portion of the rotation shaft, and the elastic member is a coil
spring having a first end supported by the end portion of the
rotation shaft and a second end supported by the support
surface.
4. The motor-operated compressor of claim 3, wherein the support
surface includes a recessed guide groove configured to receive the
second end of the elastic member.
5. The motor-operated compressor of claim 4, wherein: the end
portion of the rotation shaft includes a protrusion portion
extending in an axial direction from a center of the rotation
shaft, and the elastic member is coupled to the protrusion
portion.
6. The motor-operated compressor of claim 3, further comprising a
bearing member disposed between the support surface and the elastic
member.
7. The motor-operated compressor of claim 2, wherein: the rotation
shaft receiving portion includes an inner circumferential surface
corresponding to an outer circumferential surface of the rotation
shaft, the inner circumferential surface includes a stepped
mounting surface formed at a middle portion of the inner
circumferential surface in an axial direction of the rotation
shaft, and the elastic member is a leaf spring having opposite
sides of the leaf spring supported by the end portion of the
rotation shaft and the mounting surface.
8. The motor-operated compressor of claim 7, wherein the mounting
surface is formed in a position facing the outer circumferential
surface of the rotation shaft.
9. The motor-operated compressor of claim 1, wherein: the rotation
shaft includes a thrust portion extending in a radial direction,
the frame includes a frame shaft-receiving portion through which
the rotation shaft passes, and the thrust portion is supported on
the frame shaft-receiving portion in the first axial direction.
10. The motor-operated compressor of claim 9, wherein an annular
sealing member is positioned between the thrust portion and the
frame shaft-receiving portion.
11. The motor-operated compressor of claim 9, wherein facing
surfaces of the thrust portion and the frame shaft-receiving
portion are tilted relative to the axial direction of the rotation
shaft.
12. The motor-operated compressor of claim 11, wherein an annular
sealing member is interposed between the facing surfaces of the
thrust portion and the frame shaft-receiving portion.
13. The motor-operated compressor of claim 11, wherein a thrust
bearing is interposed between the facing surfaces of the thrust
portion and the frame shaft-receiving portion.
14. A motor-operated compressor, comprising: a fixed scroll; an
orbiting scroll engaged with the fixed scroll and configured to
perform an orbiting motion relative to the fixed scroll, the
orbiting scroll and the fixed scroll forming a pair of compression
chambers therebetween during the orbiting motion; a frame disposed
opposite to the fixed scroll with the orbiting scroll interposed
between the frame and the fixed scroll, a back pressure chamber
being formed between the frame and the orbiting scroll and
configured to axially support the orbiting scroll, and the frame
including a frame shaft-receiving portion; a rotation shaft coupled
to the frame and the orbiting scroll and penetrating through the
frame and the orbiting scroll, with the rotation shaft including a
thrust portion supported on the frame shaft-receiving portion in a
first axial direction, the rotation shaft being rotatably coupled
to the fixed scroll; and a sealing member provided between the
frame shaft-receiving portion of the frame and the thrust portion
of the rotation shaft, the sealing member being configured to seal
the back pressure chamber.
15. The motor operated compressor of claim 14, wherein: the thrust
portion includes an inclined surface relative to an axial direction
of the rotation shaft, and the frame shaft-receiving portion facing
the inclined surface of the thrust portion includes a sealing
surface formed along the inclined surface.
16. A motor-operated compressor, comprising: a fixed scroll; an
orbiting scroll engaged with the fixed scroll and configured to
perform an orbiting motion relative to the fixed scroll, and the
orbiting scroll and the fixed scroll forming a pair of compression
chambers therebetween during the orbiting motion; a frame disposed
opposite to the fixed scroll with the orbiting scroll interposed
between the frame and the fixed scroll, a back pressure chamber
being formed between the frame and the orbiting scroll, and the
back pressure chamber being configured to axially support the
orbiting scroll; a rotation shaft coupled to the frame and the
orbiting scroll and penetrating through the frame and the orbiting
scroll, and the rotation shaft being supported on the frame in a
first axial direction by a frame shaft-receiving portion of the
frame and rotatably coupled to the fixed scroll, wherein the frame
shaft-receiving portion mates with a thrust portion of the rotation
shaft along facing surfaces of the frame shaft-receiving portion
and the thrust portion of the rotation shaft that are inclined
relative to a central axis of the rotation shaft; and an elastic
member disposed between the fixed scroll and the rotation shaft,
the elastic member being configured to support the rotation shaft
in a second axial direction opposite to the first axial direction
with respect to the fixed scroll.
17. The motor-operated compressor according to claim 16, wherein a
thrust bearing member is disposed between at least a portion of the
facing surfaces of the frame shaft-receiving portion and the thrust
portion of the rotation shaft.
18. The motor-operated compressor according to claim 16, wherein a
sealing member is disposed between at least a portion of the facing
surfaces of the frame shaft-receiving portion and the thrust
portion of the rotation shaft.
19. The motor-operated compressor according to claim 16, wherein:
the fixed scroll includes a rotation shaft receiving portion
configured to accommodate at least a part of the rotation shaft,
and the elastic member is contained in the rotation shaft receiving
portion.
20. The motor-operated compressor according to claim 19, wherein
the elastic member is a spring.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] Pursuant to 35 U.S.C. .sctn. 119(a), this application claims
the benefit of earlier filing date and right of priority to Korean
Application No. 10-2018-0087383, filed on Jul. 26, 2018, the
contents of which is incorporated by reference herein in its
entirety.
BACKGROUND OF THE DISCLOSURE
1. Field of the Disclosure
[0002] The present disclosure relates to a motor-operated
compressor.
2. Description of the Related Art
[0003] Generally, compressors for compressing a refrigerant in
automotive air conditioning systems have been developed in various
forms. Recently, motor-operated compressors driven by electric
power using motors have been actively developed according to the
tendency of electricization of electric parts of vehicles.
[0004] A motor-operated compressor mainly employs a scroll
compression method suitable for a high compression ratio operation
among various compression methods. In the scroll type
motor-operated compressor, a motor unit configured as a rotary
motor is provided in a hermetic casing, and a compression unit
configured by a fixed scroll and an orbiting scroll is disposed at
one side of the motor unit. The motor unit and the compression unit
are connected to each other by a rotation shaft so that a
rotational force of the motor unit is transferred to the
compression unit. The rotational force transferred to the
compression unit causes the orbiting scroll to perform an orbiting
motion with respect to the fixed scroll, so as to form a pair of
compression chambers each having a suction chamber, an intermediate
pressure chamber, and a discharge chamber, so that a refrigerant is
sucked into each of the compression chambers, compressed therein,
and then simultaneously discharged.
[0005] As for the scroll compression method, a compressor having a
shaft-through structure in which a rotation shaft passes through a
compression unit has been disclosed. Specifically, a rotation shaft
coupling portion coupled through a center of an orbiting scroll is
formed, and an end portion of the rotation shaft, which is
rotatably inserted into the rotation shaft coupling portion, is
supported on a fixed scroll. With such a shaft-through structure, a
compressive force and a repulsive force are applied to the same
plane with respect to an orbiting scroll disk portion, and thus
they are offset with each other, thereby preventing an orbiting
scroll from being tilted caused by an action between the
compression force and the repulsive force.
[0006] Here, a back pressure chamber is formed between the orbiting
scroll and a frame. The back pressure chamber pressurizes the
orbiting scroll to make close contact with the fixed scroll so as
to maintain a sealed state of a compression chamber. Normally, the
back pressure chamber is configured to communicate with an
intermediate pressure chamber or a discharge pressure chamber.
Accordingly, a refrigerant and oil having intermediate pressure or
discharge pressure are introduced into the back pressure chamber so
as to pressurize the orbiting scroll toward the fixed scroll.
[0007] However, in such a shaft-through scroll structure, the
rotation shaft is not axially supported, thereby increasing axial
vibrations of the rotation shaft. This causes a refrigerant and oil
forming back pressure to leak to an outside of the back pressure
chamber through a contact surface between the frame and the
rotation shaft. Thus, stable back pressure is not generated in the
back pressure chamber.
[0008] Particularly, when a specific level or amount of the back
pressure is not generated at the beginning of operation of the
compressor, behavior of the rotation shaft becomes unstable. Thus,
pressure generation in the compression chamber is delayed.
SUMMARY OF THE DISCLOSURE
[0009] Therefore, one aspect of the present disclosure is to
provide a motor-operated compressor capable of maintaining back
pressure of a back pressure chamber.
[0010] Another aspect of the present disclosure is to provide a
motor-operated compressor capable of maintaining a stable sealing
state of a thrust surface for sealing a back pressure chamber by
stabilizing axial movement or behavior of a rotation shaft.
[0011] Still another aspect of the present disclosure is to provide
a motor-operated compressor capable of stabilizing axial movement
or behavior of a rotation shaft by elastically supporting the
rotation shaft in an axial direction.
[0012] Still another aspect of the present disclosure is to provide
a motor-operated compressor capable of enhancing a sealing force of
thrust surface by axially and radially supporting a rotation
shaft.
[0013] In order to achieve the aspects of the present disclosure,
there is provided a motor-operated compressor including an elastic
member provided on one end of a rotation shaft to axially support
the rotation shaft.
[0014] Here, an outer circumferential surface of the rotation shaft
may be provided with a thrust portion extending in a radial
direction, and the thrust portion may be supported on the frame
shaft-receiving portion through which the rotation shaft passes in
a direction opposite to the elastic member.
[0015] In addition, surfaces of the thrust portion and the
shaft-receiving portion facing each other may be formed in an
inclined manner.
[0016] Further, a sealing member may be fitted between the thrust
portion and the shaft-receiving portion facing each other.
[0017] In order to achieve the aspects of the present disclosure,
there is provided a motor-operated compressor including a fixed
scroll, an orbiting scroll engaged with the fixed scroll to perform
an orbiting motion and forming a pair of compression chambers
together with the fixed scroll during the orbiting motion, a frame
provided opposite to the fixed scroll with the orbiting scroll
interposed therebetween in a radial direction, and forming a back
pressure chamber so as to axially support the orbiting scroll, a
rotation shaft coupled to the frame and the orbiting scroll in a
penetrating manner and supported on the frame in a first axial
direction so as to be rotatably coupled to the fixed scroll, and an
elastic member disposed between the fixed scroll and the rotation
shaft, so as to support the rotation shaft in a second axial
direction opposite to the first axial direction with respect to the
fixed scroll.
[0018] Here, the fixed scroll may be provided with a rotation shaft
receiving portion that accommodates at least a part of the rotation
shaft, and the elastic member may be provided in the rotation shaft
receiving portion.
[0019] The rotation shaft receiving portion may include a support
surface facing an end portion of the rotation shaft, and the
elastic member may be implemented as a coil spring having both ends
thereof supported by the end portion of the rotation shaft and the
support surface.
[0020] The support surface may be provided with a guide groove
recessed corresponding to the elastic member, and one end portion
of the elastic member may be accommodated in the guide groove.
[0021] The end portion of the rotation shaft is provided with a
protrusion portion extending to an axial direction from a center,
and the elastic member may be inserted into and coupled to the
protrusion portion.
[0022] The support surface and the elastic member may further
include a bearing member disposed therebetween.
[0023] Here, the rotation shaft receiving portion may include an
inner circumferential surface corresponding to an outer
circumferential surface of the rotation shaft, the inner
circumferential surface may be provided at a middle thereof with a
mounting surface formed along an axial direction of the rotation
shaft in a stepped manner, and the elastic member may be configured
as a leaf spring having both sides thereof supported by the
rotation shaft and the mounting surface.
[0024] The mounting surface may be formed in a position facing the
outer circumferential surface of the rotation shaft.
[0025] Here, the rotation shaft may be provided with a thrust
portion extending in a radial direction, and the frame may be
provided with a frame shaft-receiving portion through which the
rotation shaft passes. The thrust portion may be supported on the
frame shaft-receiving portion in the first axial direction.
[0026] In addition, a sealing member with a ring shape may be
fitted between the thrust portion and the frame bearing portion
facing each other.
[0027] Surfaces of the thrust portion and the frame bearing portion
facing each other may be formed to be tilted along the axial
direction of the rotation shaft.
[0028] Also, a sealing member with a ring shape may be fitted
between the thrust portion and the frame bearing portion facing
each other.
[0029] Further, surfaces of the thrust portion and the frame shaft
receiving portion facing each other are provided with a thrust
bearing.
[0030] In order to achieve the aspects of the present disclosure,
there is provided a motor-operated compressor including a fixed
scroll, an orbiting scroll engaged with the fixed scroll to perform
an orbiting motion and forming a pair of compression chambers
together with the fixed scroll during the orbiting motion, a frame
provided opposite to the fixed scroll with the orbiting scroll
interposed therebetween in a radial direction, forming a back
pressure chamber so as to axially support the orbiting scroll, and
provided with a frame shaft-receiving portion, a rotation shaft
coupled to the frame and the orbiting scroll in a penetrating
manner and provided with a thrust surface to be supported on the
frame shaft-receiving portion in a first axial direction so as to
be rotatably coupled to the fixed scroll, and a sealing member
provided between the frame shaft-receiving portion and the thrust
portion of the rotation shaft so as to seal the back pressure
chamber.
[0031] Here, the thrust portion may be provided with an inclined
surface along an axial direction of the rotation shaft, and the
frame shaft-receiving portion facing the inclined surface may be
provided with a sealing surface formed in an inclined manner so as
to correspond to the inclined surface.
EFFECTS OF THE DISCLOSURE
[0032] According to the present disclosure, one axial end of a
rotation shaft is elastically supported to a frame. Thus, a sealing
force between the rotation shaft and the frame can be enhanced.
Accordingly, a back pressure chamber formed between an orbiting
scroll and the frame is securely sealed so that back pressure of
the back pressure chamber can be constantly maintained.
[0033] According to the present disclosure, as a rotation shaft is
elastically supported by an elastic member in an axial direction,
axial vibrations of the rotation shaft can be reduced. Accordingly,
behavior of the rotational shaft is stabilized so that a sealing
state of a back pressure chamber can be stably maintained.
[0034] Further, according to the present disclosure, a leakage in
an axial direction of a compression chamber can be prevented by
stabilizing behavior of a rotation shaft at the beginning of
operation of the compressor, thereby increasing compressor
efficiency.
[0035] Further, according to the present disclosure, an axial
length of a rotation shaft receiving portion can be reduced by
forming an elastic member provided on one end of the rotation shaft
as a leaf spring, thereby contributing to a smaller compressor.
[0036] Further, according to the present disclosure, a thrust
surface for supporting a rotation shaft is formed to be tilted, so
that a frame can axially and radially support the rotation shaft.
Thus, behavior of the rotation shaft can be more stable.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] FIG. 1 is a perspective view illustrating a compressor
module and an inverter module separated from a motor-operated
compressor according to one embodiment of the present
disclosure.
[0038] FIG. 2 is a sectional view illustrating an inside of the
motor-operated compressor according to FIG. 1.
[0039] FIG. 3 is a sectional view illustrating a main housing of
the motor-operated compressor according to FIG. 2 when viewed from
a side thereof.
[0040] FIG. 4 is a front view of the main housing of FIG. 3 when
viewed from a rear side.
[0041] FIG. 5 is a sectional view of a rotation shaft and a bearing
for supporting the rotation shaft according to the present
disclosure.
[0042] FIG. 6 is a planar view illustrating an engagement
relationship between an orbiting wrap and a fixed wrap having a
non-involute shape in a motor-operated compressor according to one
embodiment of the present disclosure.
[0043] FIG. 7 is a front view of a fixed scroll according to one
embodiment of the present disclosure when viewed from a front
side.
[0044] FIG. 8 is a sectional view of the fixed scroll of FIG. 7
when viewed from a side thereof.
[0045] FIG. 9 is a sectional view illustrating an engagement
relationship between a rotation shaft, fixed and orbiting scrolls
according to one embodiment of the present disclosure when viewed
from a side thereof.
[0046] FIG. 10 is a sectional view illustrating an engagement
relationship between a rotation shaft, fixed and orbiting scrolls
in accordance with another embodiment of the present disclosure
when viewed from a side thereof.
[0047] FIG. 11 is a sectional view of an inside of a motor-operated
compressor according to another embodiment of the present
disclosure.
[0048] FIG. 12 is a sectional view of a main housing in the
motor-operated compressor according to FIG. 11.
[0049] FIG. 13 is a sectional view of a main housing according to a
variation of the embodiment of FIG. 11.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0050] Description will now be given in detail of a motor-operated
compressor according to exemplary embodiments disclosed herein,
with reference to the accompanying drawings.
[0051] FIG. 1 is a perspective view illustrating a compressor
module and an inverter module separated from a motor-operated
compressor according to one embodiment of the present disclosure,
and FIG. 2 is a sectional view illustrating an inside of the
motor-operated compressor according to FIG. 1.
[0052] As illustrated, a scroll type motor-operated compressor
(hereinafter, abbreviated as a "motor-operated compressor")
according to the present disclosure may include a compressor module
101 for compressing a refrigerant, and an inverter module 201
coupled to a front side of the compressor module 101 for
controlling operation of the compressor module 101. The compressor
module 101 and the inverter module 201 may be assembled
successively, or independently manufactured and assembled. This
embodiment illustrates the latter as a representative example, but
the former and the latter may alternatively be combined such that
the compressor module and the inverter module are independently
manufactured but successively assembled.
[0053] The compressor module 101 includes a main housing 110 having
an inner space forming a motor chamber S1 and provided with an
inlet port 111 formed thereat to communicate with the motor chamber
S1, a driving motor 120 as a motor part fixed to the motor chamber
S1 of the main housing 110, a compression unit 105 provided at one
side of the driving motor 120 outside the main housing 110 to
compress a refrigerant using a rotational force of the driving
motor 120, and a rear housing 160 coupled to another side of the
compression unit 105 to form an oil separation chamber S2.
[0054] As the main housing 110 is arranged in a horizontal
direction with respect to the ground, the driving motor 120 and the
compression unit 105 are also arranged in the horizontal direction.
For the sake of explanation, a left side of FIG. 2 is designated as
a front side and a right side as a rear side.
[0055] The main housing 110 is formed in a cross-sectional cup
shape having an open front end and a partially closed rear end. The
open front end of the main housing 110 is sealed by being coupled
to an inverter housing 210 to be described later, and the partially
closed rear end of the main housing 110 is integrally formed with
the frame 112 supporting the compression unit 105. The frame 112 of
the main housing 110 is provided with a frame shaft-receiving
portion 113 formed in a cylindrical shape. A main bearing portion
132 of the rotation shaft 130 to be described later passes through
the frame shaft-receiving portion to be rotatably supported.
[0056] A frame bearing 171 implemented as a bush bearing is
inserted into and coupled to the frame shaft-receiving portion 113,
and an inner circumferential surface of the frame shaft-receiving
portion 113 is disposed apart from the main bearing portion 132 of
the rotation shaft 130, so that a back pressure chamber S3, which
will be described later, communicates with the motor chamber S1.
The inlet port 111 connected to a suction pipe (not shown) is
formed adjacent to the front end of the main housing 110, so that
the motor chamber S1 of this embodiment forms a kind of suction
space. Accordingly, in the motor-operated compressor according to
this embodiment, a refrigerant is sucked into the compression unit
through an internal space of the main housing constituting the
motor chamber, thereby forming a low-pressure compressor.
[0057] In the main housing according to this embodiment, the frame
is integrally formed, as described above. Accordingly, an
additional process of assembling the frame to the main housing is
not needed. Thus, a man-hour for assembly can be reduced and
assemblability of a driving motor can be enhanced by eliminating
the additional frame assembly process.
[0058] FIG. 3 is a sectional view illustrating a main housing of
the motor-operated compressor according to FIG. 2 when viewed from
a side thereof, and FIG. 4 is a front view illustrating the main
housing of FIG. 3 when viewed from a rear side.
[0059] As illustrated, an axial center Ob1 of the frame
shaft-receiving portion 113 is formed to coincide with an axial
center Om of the driving motor 120. To this end, a center of an
outer diameter and a center of an inner diameter of the frame 112
(i.e., a center of the frame-shaft receiving portion 113) may be
formed to coincide with each other.
[0060] However, the axial center Ob1 of the frame shaft-receiving
portion 113 may coincide with the axial center Om of the driving
motor 120, but the center of the outer diameter Oo and the center
of the inner diameter Oi of the frame 112 may not coincide with
each other. For example, as illustrated in FIGS. 3 and 4, a first
protrusion portion 114 is formed on one side in a radial direction
of the frame 112, and a first passage 114a may be formed through
the first protrusion portion 114 so as to communicate with an
inside of the motor chamber S1. The first passage 114a may be
provided with a suction passage Fg for communicating a compression
chamber V with the motor chamber S1 together with a second passage
154a of a fixed scroll 150 to be described later.
[0061] A front side, which is the frame shaft-receiving portion
113, of the frame 112 extends to a central part, that is, a
direction toward the driving motor 120, and a rear side of the
frame 112 is formed to be recessed in a direction toward the
driving motor 120 in a manner of having at least two steps.
Accordingly, the frame 112 is provided at its rear side with a
scroll receiving groove 112a in which an orbiting disk (or orbiting
end plate) portion of an orbiting scroll to be explained later is
inserted so as to be supported in an axial direction, an Oldham
ring accommodating groove 112b for accommodating an Oldham ring
180, which is a rotation-preventing mechanism therein, and a
balance weight accommodating groove 112c for rotatably
accommodating a balance weight 138 therein. The scroll receiving
groove 112a, the Oldham ring accommodating groove 112b, and the
balance weight accommodating groove 112c are consecutively formed
in a stepped manner so as to form a kind of back pressure chamber
S3.
[0062] The rear end of the frame shaft-receiving portion 113
extends in a direction toward the orbiting scroll 140 and is formed
in a cylindrical shape. The frame bearing 171 configured as a bush
bearing is inserted into and coupled to the frame shaft-receiving
portion 113. Accordingly, an outer circumferential surface of the
rear end of the frame-shaft receiving portion 113 forms the balance
weight accommodating groove 112c to create the back pressure
chamber S3.
[0063] An axial bearing surface 113a, which forms a thrust surface
together with a thrust portion 135 of the rotation shaft 130 to be
described later, is provided at the rear end of the frame
shaft-receiving portion 113.
[0064] Here, the axial bearing surface 113a of the frame
shaft-receiving portion 113 and an axial bearing surface 135a of
the thrust portion 135 provided on the rotation shaft 130 are in
close contact with each other with the frame bearing 171 interposed
therebetween, so as to seal the back pressure chamber S3. This
prevents a refrigerant and oil forming back pressure of the back
pressure chamber S3 from leaking through the thrust surface,
thereby forming stable back pressure in the back pressure chamber
S3. In this case, however, the refrigerant and oil accumulated in
the back pressure chamber S3 may be introduced into the compression
chamber again through a back pressure hole (not shown) formed in
the fixed scroll 150.
[0065] The driving motor 120 includes a stator 121 inserted into
and fixed to an inner circumferential surface of the main housing
110, and a rotor 122 positioned inside the stator 121 and rotated
by interaction with the stator 121. The rotor 122 is coupled with a
rotation shaft 130 that transfers a rotational force of the driving
motor 120 to the compression unit 105 while rotating together with
the rotor 122.
[0066] The stator 121 is fixed to the main housing 110 by
shrink-fitting (or hot press fitting). Accordingly, a shorter
length (or depth) for inserting the stator 121 into the main
housing 110 may be more suitable for the assembly, and may also be
suitable for maintaining concentricity of the stator 121 during the
stator 121 shrink-fitting process.
[0067] To this end, as illustrated in FIG. 3, when the main housing
110 has a first end 110a, which is an open end, and a second end
110b at which the frame 112 is formed, a length L1 from an axial
center CL of the stator 121 to the first end 110a may be formed to
be shorter than a length L2 from the axial center CL of the stator
121 to the second end 110b. Accordingly, as described above, an
insertion length L3 for inserting the stator 121 into the motor
chamber S1 of the main housing 110 can be shortened.
[0068] On the other hand, the rotation shaft 130 is coupled to the
center of the rotor 122 by shrink-fitting (or hot press fitting).
Opposite ends of the rotation shaft 130 may be radially supported
with the driving motor 120 interposed therebetween. However, as
described in this embodiment, one end portion of the rotation shaft
130 may be one side of the driving motor 120, that is a fixed end
radially supported at two points of the frame 112 and the fixed
scroll 150, and another end portion of the rotation shaft 130
coupled to the rotor 122 of the driving motor 120 may be a free end
in a radial direction.
[0069] FIG. 5 is a sectional view of a rotation shaft and a bearing
for supporting the rotation shaft according to the present
disclosure.
[0070] As illustrated, the rotation shaft 130 is provided with a
shaft portion 131 coupled to the rotor 122, the main bearing
portion 132 radially supported on the frame shaft-receiving portion
113 in a rotatable manner, an eccentric portion 133 eccentrically
coupled to the orbiting scroll 140, and a sub bearing portion 134
radially supported on a scroll shaft-receiving portion 156 of the
fixed scroll 150. The main bearing portion 132 and the sub bearing
portion 134 radially support the rotation shaft 130, respectively,
as described above. The eccentric portion 133 transfers a rotation
force of the driving motor 120 to the orbiting scroll 140, so that
the orbiting scroll 140 performs an orbiting motion by the Oldham
ring 180.
[0071] An oil supply passage 136 is provided in the rotation shaft
130 by a predetermined depth in a direction toward the front end
from the rear end. Oil supply holes 137a, 137b, and 137c are formed
in a middle part of the oil supply passage 136 toward an outer
circumferential surfaces of the main bearing portion 132, the
eccentric portion 133, and the sub bearing portion 134,
respectively. This will be described later again together with an
oil supply structure.
[0072] Referring back to FIG. 2, as described above, the
compression unit 105 includes the orbiting scroll 140 axially
supported on the frame 112 of the main housing 110 to perform an
orbiting motion, and the fixed scroll (or non-orbiting scroll) 150
coupled with the orbiting scroll 140 in an engaging manner and
fixedly coupled to the second end 110b forming a closed end portion
of the main housing 110. A pair of compression chambers V is formed
between the orbiting scroll 140 and the fixed scroll 150 during the
orbiting motion of the orbiting scroll 140. The compression chamber
will be described later together with an orbiting wrap and a fixed
wrap.
[0073] The orbiting scroll 140 is axially supported on the frame
112, and the Oldham ring 180 which is a rotation-preventing
mechanism for preventing rotation of the orbiting scroll 140 is
provided between the frame 112 and the orbiting scroll 140. A
pin-and-ring type may also be used for the rotation-preventing
mechanism.
[0074] In addition, the orbiting scroll 140 is provided with an
orbiting scroll disk portion (hereinafter, referred to as "orbiting
disk portion") 141 in a substantially disk shape. An orbiting wrap
142 is formed on a rear surface of the orbiting disk portion 141.
The orbiting wrap 142 is engaged with a fixed wrap 153 to be
explained later so as to form compression chambers at an inner
surface and an outer surface with respect to the fixed wrap 153.
The orbiting wrap will be explained later with the fixed wrap.
[0075] The orbiting disk portion 141 is provided with a back
pressure hole 141a for communicating the back pressure chamber S3
and an intermediate compression chamber V with each other.
Accordingly, oil or a refrigerant can flow between the back
pressure chamber S3 and the intermediate compression chamber V
according to a difference between pressure in the back pressure
chamber S3 and pressure in the intermediate compression chamber
V.
[0076] In addition, a rotation shaft coupling portion 143 to which
the eccentric portion 133 of the rotation shaft 130 is rotatably
coupled is formed through a central part of the orbiting disk
portion 141. The rotation shaft coupling portion 143 is formed in a
cylindrical shape, and a third bearing 173 forming a bearing
surface together with the eccentric portion 133 of the rotation
shaft 130 is inserted into the rotation shaft coupling portion 143.
Accordingly, the rotation shaft coupling portion 143 (or third
bearing) is formed so as to overlap the orbiting wrap 142 in a
radial direction. The rotation shaft coupling portion 143 becomes a
part of the orbiting wrap 142 which is located at the innermost
position.
[0077] The fixed scroll 150, as aforementioned, may be coupled to
the second end of main housing 110 from the outside of the main
housing 110. In this case, a sealing member such as a gasket may be
provided between the main housing 110 and the fixed scroll 150.
[0078] Referring back to FIG. 5, the rotation shaft 130 may be
provided with one oil supply passage 136 and a plurality of oil
supply holes 137a, 137b, and 137c. As described above, the oil
supply passage 136 may be formed in the one end portion of the
rotation shaft 130, that is, a direction to the front end of the
rotation shaft 130 from the rear end of it accommodated in an oil
guide space by a predetermined depth in an axial direction. The
plurality of holes 137a, 137b, and 137c may be provided in the
middle of the oil supply passage 136 in the axial direction at
predetermined intervals therebetween.
[0079] The plurality of oil supply holes 137a, 137b and 137c may
consist of a second oil supply hole 137b passing through an outer
circumferential surface of the sub bearing portion 134, a third oil
supply hole 137c passing through an outer circumferential surface
of the eccentric portion 133, and a first oil supply hole 137a
passing through an outer circumferential surface of the main
bearing portion 132.
[0080] Accordingly, oil flowing into the oil supply passage 136
from the oil guide space passes through the second oil supply hole
137b, the third oil supply hole 137c, and the first oil supply hole
137a in order, and is then supplied to each respective bearing
surface.
[0081] On the other hand, each of the orbiting wrap and the fixed
wrap may be formed in an involute shape. However, as shown in this
embodiment, when the rotation shaft is coupled through the center
of the orbiting scroll, the final compression chamber may be formed
in an eccentric position, and thus a great pressure difference may
be generated between the compression chambers. This is because, in
case of a shaft-through scroll compressor, pressure of one
compression chamber becomes much lower than pressure of another
compression chamber as the final compression chamber is formed
eccentrically from a center of a scroll. Therefore, in the
shaft-through scroll compressor, it is advantageous to form the
orbiting wrap and the fixed wrap in a non-involute shape as shown
in this embodiment.
[0082] FIG. 6 is a planar view illustrating an engagement
relationship between an orbiting wrap and a fixed wrap in a
non-involute shape in a motor-operated compressor according to one
embodiment of the present disclosure.
[0083] As illustrated, an orbiting wrap 142 according the
embodiment of the present disclosure may have a shape in which a
plurality of arcs having different diameters and origins are
connected, and the outermost curve may be formed in a substantially
elliptical shape having a major axis and a minor axis. A fixed wrap
153 may be formed in a similar manner.
[0084] A rotation shaft coupling portion 143 which forms an inner
end portion of the orbiting wrap 142 and to which an eccentric
portion 133 of a rotation shaft 130 is rotatably inserted may be
formed through a central portion of an orbiting disk portion 141 in
an axial direction. A third bearing 173 implemented as a bush
bearing may be fixedly inserted into an inner circumferential
surface of the rotation shaft coupling portion 143. An outer
circumferential part of the rotation shaft coupling portion 143 is
connected to the orbiting wrap 142 to form the compression chamber
V together with the fixed wrap 153 during a compression
process.
[0085] Furthermore, the rotation shaft coupling portion 143 may be
formed at a height overlapping with the orbiting wrap 142 on the
same plane, and thus the eccentric portion 133 of the rotation
shaft 130 may be disposed at a height overlapping with the orbiting
wrap 142 on the same plane. Accordingly, a repulsive force and a
compressive force of a refrigerant can be attenuated by each other
while being applied to the same plane based on an orbiting disk
portion, thereby preventing an inclination of an orbiting scroll
140 caused by an action of the compressive force and repulsive
force.
[0086] The rotation shaft coupling portion 143 is provided with a
concave portion 143a formed on an outer circumferential part
thereof, which faces an inner end portion of the fixed wrap 153,
and engaged with a protrusion portion 153a of the fixed wrap 153 to
be explained later. An increasing portion 143b which increases in
thickness from an inner circumferential part to the outer
circumferential part of the rotation shaft coupling portion 143 is
formed at an upstream side along a direction that a compression
chamber V is formed. This may extend a compression path of the
first compression chamber V1 immediately before discharge, and
consequently a compression ratio of the first compression chamber
V1 can be increased close to a compression ratio of the second
compression chamber V2.
[0087] An arcuate compression surface 143c having an arcuate shape
is formed at another side of the concave portion 143a. A diameter
of the arcuate compression surface 143c is determined by a
thickness of the inner end portion of the fixed wrap 153 (i.e., a
thickness of a discharge end) and an orbiting radius of the
orbiting wrap 142. When the thickness of the inner end portion of
the fixed wrap 153 increases, a diameter of the arcuate compression
surface 143c increases. As a result, a thickness of the orbiting
wrap around the arcuate compression surface 143c may increase to
ensure durability, and the compression path may extend to increase
the compression ratio of the second compression chamber V2 to that
extent.
[0088] In addition, a protrusion portion 153a is formed near the
inner end portion (a suction end or a start end) of the fixed wrap
153 corresponding to the rotation shaft coupling portion 143 in a
manner of protruding toward the outer circumferential part of the
rotation shaft coupling portion 143. The protrusion portion 153a
may be provided with a contact portion 153b protruding therefrom to
be engaged with the concave portion 143a. In other words, the inner
end portion of the fixed wrap 153 may be formed to have a larger
thickness than other portions. As a result, wrap strength at the
inner end portion of the fixed wrap 153, which is subjected to the
highest compressive force on the fixed wrap 153, may increase so as
to enhance durability.
[0089] On the other hand, the compression chamber V may be formed
between the fixed end portion 151 and the fixed wrap 153, and
between the orbiting wrap 142 and the orbiting end portion 141,
respectively, and a suction chamber, an intermediate pressure
chamber, and an oil separation chamber may be formed consecutively
along a proceeding direction of the wraps.
[0090] The compression chamber V may include a first compression
chamber V1 formed between an outer surface of the orbiting wrap 142
and an inner surface of the fixed wrap 153, and a second
compression chamber V2 formed between an inner surface of the
orbiting wrap 142 and an outer surface of the fixed wrap 153. In
other words, the first compression chamber V1 includes a
compression chamber formed between two contact points P11 and P12
generated in response to the inner surface of the fixed wrap 153
being brought into contact with the outer surface of the orbiting
wrap 142, and the second compression chamber V2 includes a
compression chamber formed between two contact points P21 and P22
generated in response to the outer surface of the fixed wrap 153
being brought into contact with the inner surface of the orbiting
wrap 142.
[0091] Here, when a larger angle of angles formed between two
lines, which connect a center of the eccentric portion, namely, a
center O of the rotation shaft coupling portion to the two contact
points P11 and P12, respectively, is defined as .alpha. within the
first compression chamber V1 just before discharge, the angle
.alpha. at least just before the discharge is larger than
360.degree. (i.e., .alpha.<360.degree.), and a distance lbetween
normal vectors at the two contact points P11 and P12 also has a
value greater than zero.
[0092] As a result, the first compression chamber immediately
before the discharge, which is formed by the fixed wrap and the
orbiting wrap according to the embodiment of the present
disclosure, may have a smaller volume than that formed by a fixed
wrap and an orbiting wrap having an involute shape. Therefore, the
compression ratios of the first and second compression chambers V1
and V2 can all be improved even without increasing the size of the
first wrap 142 and the second wrap 153.
[0093] A rear housing 160 is coupled to a second surface 150b of
the fixed scroll 150. As the rear housing 160 is coupled to the
second surface 150b of the fixed scroll 150, an oil separation
chamber S2 may be formed such that a refrigerant discharged from
the compression chamber V is accommodated therein.
[0094] Here, a separate protrusion portion (not shown) similar to a
main-side fixing protrusion portion 115 and an inverter-side fixing
protrusion portion 211, which will be described later, may be
formed on outer circumferential surfaces of the rear housing 160
and the fixed scroll 150, respectively, to be fixed through a bolt,
or a fixing bolt passing through an edge (rim) surface of the rear
housing 160 may be fastened so as to be coupled to an edge surface
of the fixed scroll 150. A sealing member such as a gasket may be
provided between the rear housing 160 and the fixed scroll 150.
[0095] An inverter housing 210 may be coupled in a covering manner
to one of both ends of the main housing 110, which is opposite to
the rear housing 160, namely, coupled to the open front end of the
main housing 110.
[0096] FIG. 7 is a planar view of a fixed scroll according to one
embodiment of the present disclosure when viewed from a front side,
and FIG. 8 is a sectional view of the fixed scroll according to
FIG. 7.
[0097] As illustrated, the fixed scroll 150 includes a fixed scroll
disk portion (hereinafter, referred to as "fixed disk portion") 151
formed in a substantially disk shape, and a side wall portion 152
formed at an edge of the fixed disk portion 151 to be coupled to a
frame-side end of the main housing 110. A fixed wrap 153 which is
engaged with the orbiting wrap 142 to form compression chambers is
formed on a front surface of the fixed disk portion 151. As
aforementioned, the fixed wrap 153 may be formed in an involute
shape together with the orbiting wrap 142, but may also be formed
in various other shapes.
[0098] A second protrusion portion 154 radially extends from an
outer circumferential surface of the side wall portion 152 so as to
correspond to the first protrusion portion 114. The second
protrusion portion 154 may be provided therein with the second
passage 154a constituting the suction passage Fg together with the
first passage 114a. Accordingly, a center of an outer diameter Oso
of the fixed scroll 150 may be different from a center Ob2 of the
frame shaft-receiving portion 113.
[0099] The second passage 154a constituting the suction passage Fg
may be formed in an axial direction, or may be formed to be
inclined as shown in FIG. 8. When the second passage 154a is formed
in the axial direction, an outer diameter of the fixed disk portion
151 may be enlarged to increase a winding length of the fixed wrap
153, compared to the same outer diameter of the main housing 110.
On the other hand, when the second passage 154a is formed to be
inclined, the winding length of the fixed wrap 153 compared with
the same capacity of the compression chamber may be reduced so as
to downsize the compressor.
[0100] As the first passage 114a and the second passage 154a
constituting the suction passage Fg are formed in the first
protrusion portion 114, and the second protrusion portion 135,
receptively. Thus, the suction passage Fg may be formed close to an
outer circumferential surface of the compressor. Accordingly, a
refrigerant sucked into the compression chamber V through the 5
suction passage Fg from the motor chamber S1 can quickly exchange
heat with external air of the compressor, which may lower a
specific volume of the refrigerant sucked into the compression
chamber V, thereby reducing a suction loss. Particularly, in the
case of the second passage 154a, since the fixed scroll 150 is
provided outside the main housing 110, the fixed scroll 150 is
positioned closer to the outside than when the fixed scroll 150 is
inserted into the main housing 110. Thus, a heat dissipation effect
of a refrigerant slightly heated while passing through the motor
chamber may be further increased.
[0101] Further, a dimple groove 152a may be formed on the outer
circumferential surface of the side wall portion 152 to reduce a
weight of the fixed scroll 150 and simultaneously prevent
deformation of the fixed scroll 150. The dimple groove 152a may be
provided in plurality arranged along a circumferential direction
with predetermined intervals, or one dimple groove 152a may be
formed long in the circumferential direction.
[0102] Since the outer circumferential surface of the side wall
portion 152 of the fixed scroll 150 is located outside the main
housing 110, an outer diameter of the fixed scroll 150 may be
greater than or equal to an inner diameter of the main housing 110.
Therefore, the outer diameter of the fixed scroll 150 can increase
on the basis of the same outer diameter of the compressor, which
may result in extending the winding lengths of the fixed wrap 153
and the orbiting wrap 142, thereby increasing a suction volume of
the compression chamber V.
[0103] An outlet port 155 which communicates a final compression
chamber V with an oil separation chamber S2 to be explained later
so as to guide a discharge of a refrigerant is formed at a central
part of the fixed disk portion 151. The outlet port 155 may be
formed in a penetrating manner from the compression chamber V to
the oil separation chamber S2 in an axial direction or inclined
direction of the fixed disk portion 151. Only one outlet port 155
may be formed to communicate a first compression chamber V1 and a
second compression chamber V2, or a first outlet port 155a and a
second outlet port 155b may be formed to communicate with the first
compression chamber V1 and the second compression chamber V2,
respectively.
[0104] FIG. 9 is a sectional view illustrating an engagement
relationship between a rotation shaft, first and second scrolls, in
accordance with one embodiment of the present disclosure.
[0105] Referring to FIG. 9 together with FIG. 8, the rotation shaft
130 is formed to pass through the orbiting scroll 140 and the frame
112 of the main housing 110. In this case, the one end portion of
the rotation shaft 130 is disposed to face the fixed scroll 150. As
aforementioned, the scroll shaft-receiving portion 156 that
radially supports the rotation shaft 130 is formed at a center of
the fixed disk portion 151 of the fixed scroll 150. The scroll
shaft-receiving portion 156 is provided with a rotation shaft
receiving portion 156c formed therein to accommodate the one end
portion of the rotation shaft 130.
[0106] The scroll shaft-receiving portion 156 may be formed by
increasing a thickness of the fixed disk portion 151. In this case,
however, not only a weight of the fixed scroll 150 is increased but
also an unnecessary portion is thickly formed. As a result, a
length of the outlet port 155 may become long, thereby increasing a
dead volume. Therefore, as illustrated, a part of the fixed disk
portion 151 may be formed to protrude. That is, it may be formed to
radially extend from the fixed disk portion 151 to the rear housing
160.
[0107] A second bearing 172 may be inserted into the scroll
shaft-receiving portion 156 to radially support the rotation shaft
130. The scroll shaft-receiving portion 156 is formed in a
cylindrical shape having a closed rear surface, so that the second
bearing 172, which forms a bearing surface together with the sub
bearing portion 134 of the rotation shaft 130, is inserted into and
coupled to an inner circumferential surface 156b of the second
shaft receiving portion 156. The second bearing 172 may be
implemented as a bush bearing or a needle bearing.
[0108] Here, the scroll shaft-receiving portion 156 may be formed
to be longer in an axial direction than an accommodated length of
the rotation shaft 130. In other words, the rotation shaft
receiving portion 156c may extend toward the rear housing. In this
case, as illustrated, an extra space not occupied by the rotation
shaft 130 is created in the rotation shaft receiving portion 156c.
The extra space of the rotation shaft receiving portion 156c may be
used as an oil guide space communicating with an oil guide passage
157.
[0109] The rotation shaft receiving portion 156c is located between
the oil guide passage 157 and the oil supply passage 136. The oil
guide passage 157 may communicate with the oil separation chamber
S2, and the oil supply passage 136 may communicate with each of the
bearing surfaces of the main bearing portion 132, the sub bearing
portion 134 and the eccentric portion 133 provided on outer
circumferential surfaces of the main bearing portion 132, the sub
bearing portion 134 and the eccentric portion 133.
[0110] The oil guide passage 157 may be provided in the fixed
scroll 150 or in the rear housing 160 when the fixed disk portion
151 is formed to be thicker.
[0111] For example, when the oil guide passage 157 is provided in
the fixed scroll 150, it may be formed to penetrate the scroll
shaft-receiving portion 156 extending toward the rear housing
160.
[0112] One end of the oil guide passage 157 passes through a side
surface of the scroll shaft-receiving portion 156 so as to
communicate with the rotation shaft receiving portion 156c, and
another end of it communicates with an oil storage tank (or
reservoir). The oil storage tank is formed on an opposite side of
the oil separation chamber S2. Referring back to FIG. 2, the oil
storage tank is provided at a lower side of the oil separation
chamber S2. High-pressure oil separated from a refrigerant in the
oil separation chamber S2 of the rear housing 160 may be quickly
introduced into the rotation shaft receiving portion 156c through
the oil guide passage 157 by a pressure difference. Then the oil
introduced into the rotation shaft receiving portion 156c may be
quickly supplied to each of the respective bearing surfaces through
the oil supply passage 136 and each of the respective oil supply
holes 137a to 137c.
[0113] According to this disclosure, an elastic member 159 may be
disposed between the fixed scroll 150 and the rotation shaft 130 to
apply an elastic force to the rotation shaft 130 in a direction
toward the frame 112. More specifically, the elastic member 159 is
provided in the rotation shaft receiving portion 156c.
[0114] The rotation shaft receiving portion 156c may include a
support surface 156a formed to face the one end portion of the
rotation shaft 130, and the inner circumferential surface 156b
formed to correspond to an outer circumferential surface of the
rotation shaft 130. Here, the outer circumferential surface of the
rotation shaft 130 may correspond to the sub bearing portion 134 of
the rotation shaft 130. In other words, the inner circumferential
surface 156b of the rotation shaft receiving portion 156c may be
formed to cover the sub bearing portion 134.
[0115] The elastic member 159 provided in the rotation shaft
receiving portion 156c is disposed to be in contact with the one
end portion of the rotation shaft 130 and the support surface 156a,
respectively. The elastic member 159 continuously applies the
elastic force to the rotation shaft 130. In this case, a sealing
force between the thrust portion 135 of the rotation shaft 130 and
the frame 112 may be enhanced, thus refrigerant or oil leaking to
the motor chamber S1 through a gap between the frame 112 and the
rotation shaft 130, that is, a bearing surface between the thrust
portion 135 and the frame 112 may be prevented. Accordingly, stable
back pressure may be formed in the back pressure chamber S3.
Particularly, an operating failure caused by insufficient or no
back pressure formed at the beginning of operation may be
avoided.
[0116] The elastic member 159 may be configured as a coil spring.
The one end portion of the rotation shaft 130 may be provided with
a protrusion portion extending from a central part toward the
support surface 156a. An outer diameter of the protrusion portion
may be smaller than an outer diameter of the sub bearing portion
134 accommodated in the scroll shaft-receiving portion 156. In
addition, the outer diameter of the protrusion portion may be
substantially the same as an inner diameter of the elastic member
159 implemented as a coil spring. Here, one end of the elastic
member 159 may be fitted into the protrusion portion. Accordingly,
the elastic member 159, which is a coil spring, may be prevented
from being displaced from its position caused by rotation of the
rotation shaft 130.
[0117] Another end of the elastic member 159 supported by being in
contact with the support surface 156a may also be displaced or
twisted from its position as it rotates. Although not illustrated,
according to this present disclosure, a guide groove (not shown)
recessed in an axial direction may be formed on the support surface
156a to guide the rotation of the elastic member 159 implemented as
a coil spring. The guide groove may have a diameter corresponding
to an outer diameter of the elastic member 159. The guide groove
may be formed in a circular shape or a ring shape corresponding to
a coil spring. The elastic member 159 is inserted into the guide
groove, and may guide the rotation of the elastic member 159
according to the rotation of the rotation shaft 130.
[0118] On the other hand, as the another end of the elastic member
159 configured as a coil spring rotates, friction with the support
surface 156a of the rotation shaft receiving portion 156c is
continuously generated. At this time, heat is generated due to the
friction between the another end of the elastic member 159 and the
support surface 156a, which may be resulted in decreasing the
overall efficiency of the compressor and reducing durability of the
elastic member 159. Further, chips separated from the elastic
member 159 or the support surface 156a are introduced into the
compression chamber, causing compression chamber damage.
[0119] Accordingly, a coating layer for reducing friction may be
formed on a surface of the support surface 156a which comes into
contact with the elastic member 159. Alternatively, the fixed
scroll 150 may be made of a cast iron material with high wear
resistance.
[0120] Although not illustrated, according to the present
disclosure, a bearing member (not shown) may be disposed between
the another end of the elastic member 159 and the support surface
156a so as to prevent friction therebetween. The bearing member
(not shown) may be a rolling bearing configured as a ball bearing,
or a rolling bearing configured as a bush bearing. Further,
friction may be minimized since oil is continuously supplied by the
oil guide passage 157.
[0121] FIG. is a sectional view illustrating an engagement
relationship between a rotation shaft, fixed and orbiting scrolls
in accordance with another embodiment of the present
disclosure.
[0122] Referring to the drawing, unlike the foregoing embodiment,
an elastic member 159' may be implemented as a leaf spring in this
embodiment.
[0123] More specifically, as aforementioned, since the second
bearing 172 is fitted into a part of an inner circumferential
surface 156b' by which the sub bearing portion 134 is covered, an
inner diameter of the part covering the sub bearing 134 may be
larger than an inner diameter of a part extending from the inner
circumferential surface 156b'. The inner diameter of the extended
part of the inner circumferential surface 156b' may be
substantially equal to or larger than an outer diameter of the
second bearing portion 134 of the rotation shaft 130.
[0124] In other words, the inner circumferential surface 156b' of
the rotation shaft receiving portion 156c may be formed to be
stepped along an axial direction, and a mounting surface 156b''
facing an end portion of the rotation shaft 130 is formed in the
stepped area. In this case, an elastic member 159' configured as a
leaf spring is disposed between the mounting surface 156b'' and the
end portion of the rotation shaft 130, so as to be in contact with
the elastic member 159' and the end portion of the rotation shaft
130, respectively. Accordingly, the elastic member 159' is
supported by the mounting surface 156b'' to elastically support the
rotation shaft 130.
[0125] In addition, as aforementioned, the end portion of the
rotation shaft 130 is provided with a protrusion portion extending
in an axial direction. A center of the elastic member 159'
configured as a leaf spring may be formed in a penetrating manner
so that the protrusion portion is fitted therein. That is, a
through hole may be formed at the center of the elastic member
159'. A diameter of the through hole is formed to correspond to a
size of the protrusion portion extending from the end portion of
the rotation shaft 130. That is, the diameter of the through hole
may be equal to or larger than an outer diameter of the protrusion
portion.
[0126] Referring back to FIGS. 2 and 3, the rotation shaft 130 is
provided with the thrust portion 135 extending therefrom in a
radial direction between the orbiting scroll 140 and the frame 112.
That is, the thrust portion 135 may extend to the radial direction
between the main bearing portion 132 and the eccentric portion 133.
The axial bearing surface 135a of the thrust portion 135 forms a
thrust surface together with the axial bearing surface 113a of the
frame shaft-receiving portion 113. An elastic force is applied to
the rotation shaft 130 in a direction toward the frame 112 by the
elastic member 159 or 159', thereby, enhancing a sealing force of
the thrust surface.
[0127] A sealing member 116 made of a polymer compound such as
Teflon may be provided on the thrust surface. The sealing member
116 may form in an annular ring shape, and be at least partially
inserted into a groove recessed from the axial bearing surface
113a, thereby effectively preventing a refrigerant and oil in the
back pressure chamber S3 from being leaked to the motor chamber
S1.
[0128] FIG. 11 is a sectional view of an inside of a motor-operated
compressor according to another embodiment of the present
disclosure, and FIG. 12 is a sectional view of a main housing of
the motor-operated compressor according to FIG. 11. FIG. 13 is a
sectional view of a main housing of a motor-operated compressor
according to a variation of the embodiment of FIG. 11.
[0129] A detailed description overlapping with the foregoing
embodiment will be omitted.
[0130] As aforementioned, a rotation shaft 130 is provided with a
thrust portion 135' extending to a radial direction. Here, the
thrust portion 135' may include an inclined surface formed to be
tilted along an axial direction of the rotation shaft 130. In other
words, the thrust portion 135' may be formed such that a diameter
of the thrust portion 135' is gradually decreased toward a frame
112.
[0131] In addition, the frame 112 may be provided with a sealing
surface 113a' formed to be tilted so as to correspond to the
inclined surface. In other words, the frame 112 may be formed to
correspond to the thrust portion 135' formed in an inclined manner.
Accordingly, a contact area, that is, the area of the thrust
surface, is increased. Thus, a sealing force between the rotation
shaft 130 and the frame 112 may be further increased. Also,
behavior of the rotation shaft 130 may be more stabilized as the
rotation shaft 130 is axially and radially supported.
[0132] Further, according to this embodiment, a thrust bearing 174
may be disposed between the thrust surface and the sealing surface.
The thrust bearing 174 may be configured as a bush bearing. In this
case, the thrust bearing 174 is formed to correspond to the thrust
surface. When the thrust bearing 174 is viewed from a side
direction, it may be seen as a trapezoidal shape. That is, the
thrust bearing may be formed to have an inner diameter and an outer
diameter gradually decreasing in a direction of the frame 112.
[0133] In FIGS. 11 and 12, a frame bearing 171 and the thrust
bearing 174 are made of a separate member, but unlike illustrated
in the drawings, the thrust bearing 174 may be integrally formed
with the frame bearing 171. That is, the frame bearing 171 is
formed such that its inner and outer diameters are consistently
(uniformly) extended along an axial direction from an area facing
the main bearing portion 132, and its inner and outer diameters are
increased to be extended from an area corresponding to the thrust
surface. In this case, the area that comes into close contact with
the bearing is increased, thereby increasing a sealing force of the
back pressure chamber.
[0134] FIG. 13 is a sectional view of a main housing according to a
modification of the embodiment of FIG. 11.
[0135] Unlike the foregoing embodiment, a sealing member 175 may be
disposed on a thrust surface formed in an inclined manner. A groove
may be formed in any one of the inclined surface of a thrust
portion 135 and a sealing surface 113a' of a frame 112. At least a
part of the sealing member 175 may be inserted into the groove.
[0136] The foregoing embodiments are merely illustrative to
practice the rotary compressor according to an embodiment of the
present disclosure. Therefore, the present disclosure is not
limited to the above-described embodiments, and it will be
understood by those of ordinary skill in the art that various
changes in form and details may be made therein without departing
from the scope of the present disclosure.
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