U.S. patent application number 15/765235 was filed with the patent office on 2018-10-18 for compressor.
The applicant listed for this patent is DAIKIN INDUSTRIES, LTD.. Invention is credited to Masahiro YAMADA.
Application Number | 20180298900 15/765235 |
Document ID | / |
Family ID | 58694996 |
Filed Date | 2018-10-18 |
United States Patent
Application |
20180298900 |
Kind Code |
A1 |
YAMADA; Masahiro |
October 18, 2018 |
COMPRESSOR
Abstract
A compressor includes a compression mechanism housed in a
casing. The compression mechanism includes a suction volume
adjustment mechanism capable of switching a suction completion
position of a compression chamber in a suction process between a
first position and a second position with a smaller suction volume
than the first position. The suction volume adjustment mechanism
includes a plunger switchable between a closed position in which
the suction completion position is moved to the first position and
an open position in which the suction completion position is moved
to the second position. An oil passage is arranged to allow an oil
reservoir formed inside the casing and a suction space of the
compression chamber to communicate with each other. The plunger is
disposed midway along the oil passage, and includes a switching
portion closing the oil passage in the closed position, and opening
the oil passage in the open position.
Inventors: |
YAMADA; Masahiro;
(Osaka-shi, Osaka, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DAIKIN INDUSTRIES, LTD. |
Osaka-shi, Osaka |
|
JP |
|
|
Family ID: |
58694996 |
Appl. No.: |
15/765235 |
Filed: |
October 24, 2016 |
PCT Filed: |
October 24, 2016 |
PCT NO: |
PCT/JP2016/004676 |
371 Date: |
March 30, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04C 18/0215 20130101;
F04C 18/02 20130101; F04C 29/02 20130101 |
International
Class: |
F04C 18/02 20060101
F04C018/02; F04C 29/02 20060101 F04C029/02 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 11, 2015 |
JP |
2015-220912 |
Claims
1. A compressor comprising: a compression mechanism; and a casing
housing the compression mechanism, the compression mechanism
including a suction volume adjustment mechanism capable of
switching a suction completion position of a compression chamber in
a suction process between a first position and a second position in
which a suction volume is smaller than in the first position, the
suction volume adjustment mechanism including a plunger switchable
between a closed position in which the suction completion position
is moved to the first position and an open position in which the
suction completion position is moved to the second position, the
compressor further including an oil passage arranged to allow an
oil reservoir formed inside the casing and a suction space of the
compression chamber to communicate with each other, and the plunger
being disposed midway along the oil passage, and including a
switching portion closing the oil passage in the closed position to
allow the oil reservoir not to communicate with the suction space
of the compression chamber, and opening the oil passage in the open
position to allow the oil reservoir to communicate with the suction
space of the compression chamber.
2. The compressor of claim 1, wherein the compression mechanism
includes a fixed scroll, and an orbiting scroll meshing with the
fixed scroll to compress a working fluid.
3. The compressor of claim 2, wherein the oil passage has one end
communicating with the oil reservoir and an other end communicating
with the suction space of the compression mechanism, and the oil
reservoir is formed in a crank chamber that is a space inside the
housing of the compression mechanism.
4. The compressor of claim 2, wherein the oil passage includes an
orbiting-scroll-side oil passage and a fixed-scroll-side oil
passage communicating with the orbiting-scroll-side oil passage,
the orbiting-scroll-side oil passage has one end communicating with
the fixed-scroll-side oil passage, and an other end opposite to the
one end thereof communicating with the oil reservoir, and the
fixed-scroll-side oil passage has one end communicating with the
orbiting-scroll-side oil passage, and an other end opposite to the
one end thereof communicating with the suction space of the
compression mechanism.
5. The compressor of claim 2, wherein the oil passage has an oil
supply pipe having one end communicating with the oil reservoir,
and an other end communicating with the suction space of the
compression mechanism.
6. The compressor of claim 2, wherein the oil passage has an oil
supply pipe having one end communicating with an oil supply pump
provided to a drive shaft of the compression mechanism, and an
other end communicating with the suction space of the compression
mechanism.
7. The compressor of claim 3, wherein the oil passage has a fixed
scroll inner passage passing through an interior of the fixed
scroll to communicate with the plunger and the suction space of the
compression mechanism.
8. The compressor of claim 3, wherein the oil passage has a fixed
scroll outer passage passing through a space formed outside the
fixed scroll and inside the casing to communicate with the plunger
and the suction space of the compression mechanism.
9. The compressor of claim 3, wherein the suction volume adjustment
mechanism has a discharge passage arranged to discharge the working
fluid from the plunger in the second position into a space formed
outside the fixed scroll and inside the casing, and the oil passage
has an oil mix passage having one end communicating with the
plunger, and an other end communicating with the discharge
passage.
10. The compressor of claim 1, wherein the plunger is a cylindrical
valve body, and has an outer surface provided with a
circumferential groove that is disposed on the oil passage in the
second position and is deviated from the oil passage in the first
position.
11. The compressor of claim 10, wherein the plunger includes a
sealing member at both sides of the circumferential groove formed
in the outer surface of the plunger.
12. The compressor of claim 4, wherein the oil passage has a fixed
scroll inner passage passing through an interior of the fixed
scroll to communicate with the plunger and the suction space of the
compression mechanism.
13. The compressor of claim 4, wherein the oil passage has a fixed
scroll outer passage passing through a space formed outside the
fixed scroll and inside the casing to communicate with the plunger
and the suction space of the compression mechanism.
14. The compressor of claim 4, wherein the suction volume
adjustment mechanism has a discharge passage arranged to discharge
the working fluid from the plunger in the second position into a
space formed outside the fixed scroll and inside the casing, and
the oil passage has an oil mix passage having one end communicating
with the plunger, and an other end communicating with the discharge
passage.
15. The compressor of claim 5, wherein the oil passage has a fixed
scroll inner passage passing through an interior of the fixed
scroll to communicate with the plunger and the suction space of the
compression mechanism.
16. The compressor of claim 5, wherein the oil passage has a fixed
scroll outer passage passing through a space formed outside the
fixed scroll and inside the casing to communicate with the plunger
and the suction space of the compression mechanism.
17. The compressor of claim 5, wherein the suction volume
adjustment mechanism has a discharge passage arranged to discharge
the working fluid from the plunger in the second position into a
space formed outside the fixed scroll and inside the casing, and
the oil passage has an oil mix passage having one end communicating
with the plunger, and an other end communicating with the discharge
passage.
18. The compressor of claim 6, wherein the oil passage has a fixed
scroll inner passage passing through an interior of the fixed
scroll to communicate with the plunger and the suction space of the
compression mechanism.
19. The compressor of claim 6, wherein the oil passage has a fixed
scroll outer passage passing through a space formed outside the
fixed scroll and inside the casing to communicate with the plunger
and the suction space of the compression mechanism.
20. The compressor of claim 6, wherein the suction volume
adjustment mechanism has a discharge passage arranged to discharge
the working fluid from the plunger in the second position into a
space formed outside the fixed scroll and inside the casing, and
the oil passage has an oil mix passage having one end communicating
with the plunger, and an other end communicating with the discharge
passage.
Description
TECHNICAL FIELD
[0001] The present disclosure is directed to a compressor including
a suction bypass mechanism configured to change a position at which
a suction process is completed and a compression process is started
(hereinafter referred to as "suction completion position") to
adjust a suction volume. The present disclosure relates to a
technique of solving lubricant shortage in a compression
mechanism.
BACKGROUND ART
[0002] In conventional compressors, inverters are widely used to
allow the compressors to be used in various operations ranging from
an operation at a high rotational speed to an operation at a low
rotational speed. Generally, during an operation at a high
rotational speed, the flow rate of a refrigerant inside a
compressor is increased. This increases the amount of refrigerating
machine oil to be sucked together with the refrigerant to be
supplied to a compression mechanism of the compressor, resulting in
an increase in the amount of the refrigerating machine oil to be
discharged together with the refrigerant compressed. Therefore, it
has been desired to reduce the amount of refrigerating machine oil
to be supplied to the interior of the compression mechanism.
[0003] It has been suggested to provide a capacity adjusting
mechanism to a compression mechanism in order to achieve
performance of inverter control not only when a compressor is
operated at a high rotational speed (hereinafter referred to as
"the operation at the high operation capacity") but also when the
compressor is operated at a low rotational speed (hereinafter
referred to as "the operation at the low operation capacity" (See
Patent Document 1). At the low operation capacity, the operation is
generally performed at a low rotational speed, and its performance
is lower at the low rotational speed than at the high rotational
speed. In order to reduce performance degradation at the low
rotational speed, it is preferable to allow the capacity adjusting
mechanism to reduce the suction volume to increase the rotational
speed.
[0004] For example, Patent Document 1 discloses a suction bypass
mechanism which adjusts a suction volume by changing a suction
completion position in a scroll compressor. The suction bypass
mechanism of Patent Document 1 includes a plunger (valve) serving
as an opening/closing mechanism allowing first and second
compression chambers to switch between a communicating state and a
shut-off state, the first compression chamber being provided
between the inner peripheral surface of a fixed scroll and the
outer peripheral surface of an orbiting scroll, and the second
compression chamber being provided between the outer peripheral
surface of the fixed scroll and the inner peripheral surface of the
orbiting scroll. If this suction bypass mechanism allows the first
and second compression chambers to communicate with each other, the
suction completion position is changed from the position of the
shut-off state to a position in which the suction volume is
reduced. According to this configuration, in a situation where the
operation capacity is substantially constant, a smaller suction
volume allows the compression mechanism to be operated at a high
rotational speed. This can achieve its performance.
CITATION LIST
Patent Document
[0005] [Patent Document 1] Japanese Unexamined Patent Publication
No. 2007-154761
SUMMARY OF THE INVENTION
Technical Problem
[0006] However, in a situation where the compressor is controlled
at a low operation capacity, if the compressor is tried to be
rotated at a higher speed than a situation where the capacity is
not controlled, its performance can be less reduced than the
situation where the capacity is not controlled. However, oil to be
supplied to the compression chamber is insufficient due to the low
operation capacity, and an oil film is not sufficiently formed
inside the compression mechanism, resulting in insufficient
performance.
[0007] That is to say, if oil loss at the high rotation capacity is
reduced, oil supply necessary for forming the oil film inside the
compression mechanism at the low operation capacity is also
insufficient. Thus, in the compressor, it is actually difficult to
reduce performance degradation at the low operation capacity and
oil loss at the high operation capacity.
[0008] In view of the foregoing background, it is therefore an
object of the present disclosure to provide a technique of
improving performance of a compressor at a low operation capacity
while reducing oil loss at a high operation capacity.
Solution to the Problem
[0009] A first aspect of the present disclosure is directed to a
compressor including: a compression mechanism (20); and a casing
(10) housing the compression mechanism (20), the compression
mechanism (20) including a suction volume adjustment mechanism (30)
capable of switching a suction completion position of a compression
chamber (25a, 25b) in a suction process between a first position
and a second position in which the suction volume is smaller than
in the first position, the suction volume adjustment mechanism (30)
including a plunger (33) switchable between a closed position in
which the suction completion position is moved to the first
position and an open position in which the suction completion
position is moved to the second position.
[0010] This compressor further includes an oil passage (51) to
allow an oil reservoir (18, 50) formed inside the casing (10) and a
suction space (25s) of the compression chamber (25a, 25b) to
communicate with each other, and the plunger (33) is disposed
midway of the oil passage (51), and includes a switching portion
(65) closing the oil passage (51) in the closed position to allow
the oil reservoir (18, 50) not to communicate with the suction
space (25s) of the compression chamber (25a, 25b), and opening the
oil passage (51) in the open position to allow the oil reservoir
(50) to communicate with the suction space (25s) of the compression
chamber (25a, 25b).
[0011] According to the first aspect, if the suction completion
position is in the first position, the plunger (33) is in the
closed position. At that time, the oil passage (51) is blocked, and
thus, no oil is supplied from the oil reservoir (18, 50) to the
suction space (25s) of the compression chamber (25a, 25b). In
contrast, if the suction completion position is in the second
position, in which the suction volume is reduced, the plunger (33)
is in the open position. At that time, the oil passage (51) is
opened, and thus, oil is supplied from the oil reservoir (18, 50)
to the suction space (25s) of the compression chamber (25a, 25b) by
a negative pressure in the suction space (25s).
[0012] A second aspect of the present disclosure is an embodiment
of the first aspect of the present disclosure. In the second
aspect, the compression mechanism (20) is a compression mechanism
(20) including a fixed scroll (21), and an orbiting scroll (22)
meshing with the fixed scroll (21) and compressing a working
fluid.
[0013] According to the second aspect, if in the scroll compressor,
the suction completion position is in the first position and the
plunger (33) is in the closed position, the oil passage (51) is
blocked. Thus, no oil is supplied from the oil reservoir (18, 50)
to the suction space (25s) of the compression chamber (25a, 25b).
If the suction completion position is in the second position and
the plunger (33) is in the open position in which the suction
volume is reduced, the oil passage (51) is opened. Thus, oil is
supplied from the oil reservoir (18, 50) to the suction space (25s)
of the compression chamber (25a, 25b) by the negative pressure.
[0014] A third aspect of the present disclosure is an embodiment of
the second aspect of the present disclosure. In the third aspect,
the oil passage (51) has one end communicating with the oil
reservoir (50) formed in a crank chamber (23e) that is a space
inside the housing (23) of the compression mechanism (20), and the
other end communicating with the suction space (25s) of the
compression mechanism (20).
[0015] According to the third aspect, if the suction completion
position is in the second position and the suction volume is
reduced, the plunger (33) is in the open position and the oil
passage (51) is opened. Thus, oil is supplied from the oil
reservoir (18, 50) formed in the space (the crank chamber (23e))
inside the housing of the compression mechanism (20) to the suction
space (25s) of the compression chamber (25a, 25b) by the negative
pressure.
[0016] A fourth aspect of the present disclosure is an embodiment
of the second aspect of the present disclosure. In the fourth
aspect, the oil passage (51) includes an orbiting-scroll-side oil
passage (55) and a fixed-scroll-side oil passage (52) communicating
with the orbiting-scroll-side oil passage (55), the
orbiting-scroll-side oil passage (55) has one end communicating
with the fixed-scroll-side oil passage (52), and the other end
opposite to one end and communicating with the oil reservoir (50),
and the fixed-scroll-side oil passage (52) has one end
communicating with the orbiting-scroll-side oil passage (55), and
the other end opposite to one end and communicating with the
suction space (25s) of the compression mechanism (20).
[0017] According to the fourth aspect, if the suction completion
position is in the second position and the suction volume is
reduced, the plunger (33) is in the open position and the oil
passage (51) comprised of the orbiting-scroll-side oil passage (55)
and the fixed-scroll-side oil passage (52) is opened. Thus, oil is
supplied from the oil reservoir (18, 50) to the suction space (25s)
of the compression chamber (25a, 25b) by the negative pressure.
[0018] A fifth aspect of the present disclosure is an embodiment of
the second aspect of the present disclosure. In the fifth aspect,
the oil passage (51) has an oil supply pipe (56) having one end
communicating with the oil reservoir (18) formed inside the casing
(10), and the other end communicating with the suction space (25s)
of the compression mechanism (20).
[0019] According to the fifth aspect, if the suction completion
position is in the second position and the suction volume is
reduced, the plunger (33) is in the open position and the oil
passage (51) is opened. Thus, oil is supplied from the oil
reservoir (18, 50) formed in the casing (10) to the suction space
(25s) of the compression chamber (25a, 25b) by the negative
pressure.
[0020] A sixth aspect of the present disclosure is an embodiment of
the second aspect of the present disclosure. In the sixth aspect,
the oil passage (51) has an oil supply pipe (57) having one end
communicating with an oil supply pump (43a) provided to a drive
shaft of the compression mechanism (20), and the other end
communicating with the suction space (25s) of the compression
mechanism (20).
[0021] According to the sixth aspect, if the suction completion
position is in the second position and the suction volume is
reduced, the plunger (33) is in the open position and the oil
passage (51) is opened. Thus, oil is supplied from the oil supply
pump (43a) to the suction space (25s) of the compression chamber
(25a, 25b).
[0022] A seventh aspect of the present disclosure is an embodiment
of any one of the third to sixth aspects of the present disclosure.
In the seventh aspect, the oil passage (51) has a fixed scroll
inner passage (53) passing through an interior of the fixed scroll
(21) to communicate with the plunger (33) and the suction space
(25s) of the compression mechanism (20).
[0023] According to the seventh aspect, if the suction completion
position is in the second position and the suction volume is
reduced, the plunger (33) is in the open position and the oil
passage (51) is opened. Thus, oil is supplied to the suction space
(25s) of the compression chamber (25a, 25b) through the fixed
scroll inner passage (53) in the interior of the fixed scroll
(21).
[0024] An eighth aspect of the present disclosure is an embodiment
of any one of the third to sixth aspects of the present disclosure.
In the eighth aspect, the oil passage (51) has a fixed scroll outer
passage (58) passing through a space formed outside the fixed
scroll (21) and inside the casing (10) to communicate with the
plunger (33) and the suction space (25s) of the compression
mechanism (20).
[0025] According to the eighth aspect, if the suction completion
position is in the second position and the suction volume is
reduced, the plunger (33) is in the open position and the oil
passage (51) is opened. Thus, oil is supplied from the oil
reservoir (18, 50) formed in the casing (10) to the suction space
(25s) of the compression chamber (25a, 25b) through the space
formed outside the fixed scroll (21) and inside the casing
(10).
[0026] A ninth aspect of the present disclosure is an embodiment of
any one of the third to sixth aspects of the present disclosure. In
the ninth aspect, the suction volume adjustment mechanism (30) has
a discharge passage (60) discharging the working fluid from the
plunger (33) in the second position into a space formed outside the
fixed scroll (21) and inside the casing (10), and the oil passage
(51) has an oil mix passage (53a) having one end communicating with
the plunger (33), and the other end communicating with the
discharge passage (60).
[0027] According to the ninth aspect, if the suction completion
position is in the second position and the suction volume is
reduced, the plunger (33) is in the open position and the oil
passage (51) including the oil mix passage (53a) communicating with
the discharge passage (60) is opened. Thus, oil is supplied from
the oil reservoir (18, 50) formed in the casing (10) to the suction
space (25s) of the compression chamber (25a, 25b) through the space
formed outside the fixed scroll (21) and inside the casing
(10).
[0028] A tenth aspect of the present disclosure is an embodiment of
any one of the one to ninth aspects of the present disclosure. In
the tenth aspect, the plunger (33) is a cylindrical valve body, and
has an outer surface provided with a circumferential groove (33d)
that is disposed on the oil passage (51) in the second position and
is deviated from the oil passage (51) in the first position.
[0029] An eleventh aspect of the present disclosure is an
embodiment of the tenth aspect of the present disclosure. In the
eleventh aspect, the plunger (33) includes a sealing member (33e)
at both sides of the circumferential groove (33d) formed in the
outer surface of the plunger (33).
Advantages of the Invention
[0030] According to the first aspect of the present disclosure, if
the suction completion position is in the first position and no
capacity control is performed, the plunger (33) is in the closed
position to block the oil passage (51). This operation is the
operation performed a high operation capacity, and the flow rate of
the refrigerant inside the compressor is increased. Thus, oil is
sufficiently sucked into the compression chambers (25a, 25b) and
excessive oil is not supplied from the oil passage (51) to the
compression chambers (25a, 25b). This reduces oil loss while
maintaining its performance.
[0031] In contrast, if the suction completion position is in the
second position and the capacity is controlled such that the
suction volume is reduced, the plunger (33) is in the open position
and the oil passage (51) is opened. This operation is the operation
performed a low operation capacity, and the flow rate of the
refrigerant inside the compressor is decreased. Therefore, although
oil mixed in the refrigerant is insufficiently sucked into the
compression chambers (25a, 25b), oil is supplied from the oil
passage (51) to the compression chambers (25a, 25b) as well.
According to the first aspect of the present disclosure, at that
time, the oil film can be sufficiently formed in the interior of
the compression mechanism, compared to the case where the capacity
of the compressor is not controlled. This can improve performance
of the compressor.
[0032] According to the second aspect of the present disclosure, in
the scroll compressor, if the suction completion position is in the
first position and no capacity control is performed, the plunger
(33) is in the closed position to block the oil passage (51). This
operation is the operation performed a high operation capacity, and
the flow rate of the refrigerant inside the compressor is
increased. Thus, oil is sufficiently sucked into the compression
chambers (25a, 25b) and excessive oil is not supplied from the oil
passage (51) to the compression chambers (25a, 25b). This reduces
oil loss while maintaining its performance.
[0033] In contrast, if the suction completion position is in the
second position and the capacity is controlled such that the
suction volume is reduced, the plunger (33) is in the open position
and the oil passage (51) is opened. This operation is the operation
performed a low operation capacity, and the flow rate of the
refrigerant inside the compressor is decreased. Therefore, although
oil mixed in the refrigerant is insufficiently sucked into the
compression chambers (25a, 25b), oil is supplied from the oil
passage (51) to the compression chambers (25a, 25b) as well.
According to the second aspect of the present disclosure, at that
time, the oil film can be sufficiently formed in the interior of
the compression mechanism, compared to the case where the capacity
of the compressor is not controlled. This can improve performance
of the compressor.
[0034] According to the third aspect of the present disclosure, oil
can be supplied to the compression chambers (25a, 25b) during
adjustment of the suction volume using the oil passage (51) having
one end communicating with the oil reservoir (18, 50) formed in the
space inside the housing (23) of the compression mechanism (20)
(the crank chamber (23e)), and the other end communicating with the
suction space (25s) of the compression mechanism (20). Therefore,
this can improve performance of the scroll compressor with a simple
configuration.
[0035] According to the fourth aspect of the present disclosure,
oil can be supplied to the compression chambers (25a, 25b) during
adjustment of the suction volume, using the oil passage (51)
comprised of the orbiting-scroll-side oil passage (55) and the
fixed-scroll-side oil passage (52), and having one end
communicating with the oil reservoir (18, 50) and the other end
communicating with the suction space (25s) of the compression
mechanism (20). Therefore, this can reduce performance degradation
of the scroll compressor and oil loss with a simple
configuration.
[0036] According to the fifth aspect of the present disclosure, oil
can be supplied to the compression chambers (25a, 25b) during
adjustment of the suction volume using the oil passage (51) having
one end communicating with the oil reservoir (18, 50) formed in the
casing (10) of the compressor, and the other end communicating with
the suction space (25s) of the compression mechanism (20).
Therefore, this can improve performance of the scroll compressor
with a simple configuration.
[0037] According to the sixth aspect of the present disclosure, oil
can be supplied to the compression chambers (25a, 25b) during
adjustment of the suction volume using the oil passage (51) having
one end communicating with the oil supply pump (43a), and the other
end communicating with the suction space (25s) of the compression
mechanism (20). Therefore, this can improve performance of the
scroll compressor with a simple configuration.
[0038] According to the seventh aspect of the present disclosure,
oil can be supplied to the compression chambers (25a, 25b) during
adjustment of the suction volume using the oil passage (51) having
the fixed scroll inner passage (53) passing through the inside of
the fixed scroll (21) to communicate with the plunger (33) and the
suction space (25s) of the compression mechanism (20). Therefore,
this can improve performance of the scroll compressor with a simple
configuration.
[0039] According to the eighth aspect of the present disclosure,
oil can be supplied to the compression chambers (25a, 25b) during
adjustment of the suction volume using the oil passage (51) having
the fixed scroll outer passage (58) passing through the space
formed outside the fixed scroll (21) and inside the casing (10) to
communicate with the plunger (33) and the suction space (25s) of
the compression mechanism (20). Therefore, this can improve
performance of the scroll compressor with a simple
configuration.
[0040] According to the ninth aspect of the present disclosure, oil
can be supplied to the compression chambers (25a, 25b) during
adjustment of the suction volume using the oil passage (51) having
the oil mix passage (53a) communicating with the discharge passage
(60) discharging the working fluid from the plunger (33) into the
space formed outside the fixed scroll (21) and inside the casing
(10). Therefore, this can improve performance of the scroll
compressor with a simple configuration.
[0041] According to the tenth aspect of the present disclosure, a
suction volume adjustment mechanism (30) can be provided with a
simple configuration having the plunger (33) that is a cylindrical
valve body. According to the eleventh aspect of the present
disclosure, the plunger (33) is provided with the sealing member
(33e), thereby making it possible to reduce oil leakage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0042] FIG. 1 is a vertical cross-sectional view of a compressor
according to a first embodiment.
[0043] FIG. 2 illustrates the shape of a fixed scroll and the shape
of an orbiting scroll in a cross-section taken along line II-II of
FIG. 1.
[0044] FIG. 3 is an enlarged cross-sectional view of a compression
mechanism.
[0045] FIG. 4 illustrates a cross-sectional structure of an
opening/closing mechanism.
[0046] FIG. 5 is an enlarged front view of a plunger.
[0047] FIG. 6 is a plan view illustrating the shape of a transverse
passage of an oil passage.
[0048] FIG. 7 illustrates the compression mechanism in a first
operation state.
[0049] FIG. 8 illustrates the compression mechanism in a second
operation state.
[0050] FIG. 9 illustrates the compression mechanism in a third
operation state.
[0051] FIG. 10 illustrates the compression mechanism in a fourth
operation state.
[0052] FIG. 11 illustrates the compression mechanism in a fifth
operation state.
[0053] FIG. 12 illustrates the compression mechanism in a sixth
operation state.
[0054] FIG. 13 illustrates a cross-sectional structure of a
compression mechanism according to a variation of the first
embodiment.
[0055] FIG. 14 is a plan view of the fixed scroll of the
compression mechanism of FIG. 3.
[0056] FIG. 15 is a vertical cross-sectional view of a compressor
according to a second embodiment.
[0057] FIG. 16 is an enlarged cross-sectional view of a compression
mechanism in FIG. 15.
[0058] FIG. 17 is a vertical cross-sectional view of a compressor
according to a third embodiment.
[0059] FIG. 18 is a vertical cross-sectional view of a compressor
according to a fourth embodiment.
[0060] FIG. 19 is a plan view of a compressor according to a fifth
embodiment.
[0061] FIG. 20 is a cross-sectional view illustrating a first state
of a plunger of the compression mechanism of FIG. 19.
[0062] FIG. 21 is a cross-sectional view illustrating a second
state of the plunger of the compression mechanism of FIG. 19.
[0063] FIG. 22 is a plan view of a compressor according to a sixth
embodiment.
[0064] FIG. 23 is a cross-sectional view illustrating a
configuration for the plunger of the compression mechanism of FIG.
22.
[0065] FIG. 24 is an enlarged view of a plunger according to a
variation.
DESCRIPTION OF EMBODIMENTS
[0066] Embodiments of the present disclosure will now be described
in detail with reference to the drawings.
First Embodiment
[0067] A first embodiment of the present disclosure is now
described.
[0068] A scroll compressor according to this embodiment is provided
to, e.g., a refrigerant circuit of an air conditioner performing a
vapor compression refrigeration cycle, and compresses a
low-pressure refrigerant that has been sucked from an evaporator to
discharge it into a condenser.
[0069] As illustrated in FIG. 1, the scroll compressor (1) is a
so-called hermetic compressor. This scroll compressor (1) includes
a casing (10) that is a hermetically-sealed container with a
vertically oriented cylindrical shape. The casing (10) includes a
body (11) with a vertically oriented cylindrical shape, an upper
end plate (12) fixed to the upper end of the body (11), and a lower
end plate (13) fixed to the lower end of the body (11).
[0070] This casing (10) houses a compression mechanism (20)
compressing a refrigerant, and an electric motor (45) driving the
compression mechanism (20). The electric motor (45) is disposed
below the compression mechanism (20), and is coupled to the
compression mechanism (20) through a drive shaft (40) that is a
rotational shaft. The electric motor (45) is implemented as a
brushless DC motor controlled by an inverter to adjust a rotational
speed to be variable.
[0071] A discharge pipe (15) passes through and is attached to the
upper end plate (12) that is a top of the casing (10). This
discharge pipe (15) has its terminal end (the lower end in the
figure) connected to the compression mechanism (20). A suction pipe
(14) passes through and is attached to the body (11) of the casing
(10). This suction pipe (14) has its terminal end (the right end in
the figure) open toward a space between the compression mechanism
(20) and the electric motor (45) in the casing (10).
[0072] The drive shaft (40) is disposed on the vertical center line
of the casing (10). The drive shaft (40) is a crank shaft including
a main shaft portion (41) and an eccentric portion (42). The
eccentric portion (42) has a smaller diameter than the main shaft
portion (41), and is formed on the upper surface of the main shaft
portion (41). The eccentric portion (42) is eccentric from the
axial center of the main shaft portion (41) by a predetermined
dimension, and constitutes an eccentric pin. FIGS. 1 and 2 show a
state where the main shaft portion (41) and the eccentric portion
(42) are coaxially disposed. That is because FIGS. 1 and 2 are
cross-sections viewed from a position in which the center of the
main shaft portion (41) and the center of the eccentric portion
(42) are on the same line. For example, if the compressor is viewed
from its lateral direction of FIGS. 1 and 2, the center of the main
shaft portion (41) and the center of the eccentric portion (42) are
eccentric from each other.
[0073] A lower bearing holder (48) is fixed to a portion adjacent
to the lower end of the body (11) of the casing (10). This lower
bearing holder (48) rotatably supports the lower end of the main
shaft portion (41) of the drive shaft (40) through a sliding
bearing (48a).
[0074] The interior of the drive shaft (40) is provided with an oil
supply passage (44) extending vertically. The lower end of the main
shaft portion (41) is provided with an oil supply pump (43). This
oil supply pump (43) sucks refrigerating machine oil from the
bottom of the casing (10). The refrigerating machine oil passes
through the oil supply passage (44) of the drive shaft (40) to be
supplied to the sliding portion of the compression mechanism (20)
and the bearing of the drive shaft (40).
[0075] The electric motor(45) is comprised of a stator (46) and a
rotor (47). The stator (46) is fixed to the body (11) of the casing
(10). The rotor (47) is coupled to the main shaft portion (41) of
the drive shaft (40) to drive the drive shaft (40) in rotation.
[0076] The compression mechanism (20) includes a fixed scroll (21),
an orbiting scroll (22), and a housing (23) fixing and supporting
the fixed scroll (21). The fixed scroll (21) and the orbiting
scroll (22) respectively include spiral laps (21b, 22b) meshing
with each other on end plates (21a, 22a), which will be described
later. The compression mechanism (20) is configured such that the
orbiting scroll (22) rotates eccentrically relative to the fixed
scroll (21).
[0077] The housing (23) is comprised of a body (23a) and a bearing
holder (23b). The body (23a) is formed to be vertically continuous
with the bearing holder (23b), and the body (23a) is fitted into
and coupled to the body (11) of the casing (10). The bearing holder
(23b) has a smaller diameter than the body (23a), and protrudes
downward from the body (23a). The bearing holder (23b) rotatably
supports the main shaft portion (41) of the drive shaft (40)
through a sliding bearing (23c).
[0078] The fixed scroll (21) is comprised of a fixed end plate
(21a), a fixed lap (21b), and an edge portion (21c). The fixed end
plate (21a) is formed to have a substantially disk shape. The fixed
lap (21b) stands near the middle portion of the lower surface of
the fixed end plate (21a), and is integrally formed with the fixed
end plate (21a). The fixed lap (21b) is formed to have a spiral
wall shape with a constant height. The edge portion (21c) is a wall
extending downward from the outer peripheral portion of the fixed
end plate (21a), and has a lower surface overlapping with the upper
surface of the body (23a) of the housing (23) to be fixed to the
housing (23).
[0079] The orbiting scroll (22) is comprised of an orbiting end
plate (22a), an orbiting lap (22b), and a boss (22c). The orbiting
end plate (22a) is formed to have a substantially disk shape. The
orbiting lap (22b) stands on the upper surface of the orbiting end
plate (22a), and is integrally formed with the orbiting end plate
(22a). The orbiting lap (22b) is formed to have a spiral wall shape
with a constant height, and to mesh with the fixed lap (21b) of the
fixed scroll (21). The boss (22c) extends downwardly from the lower
surface of the orbiting end plate (22a), and integrally formed with
the orbiting end plate (22a).
[0080] The eccentric portion (42) of the drive shaft (40) is
inserted into the boss (22c) through a sliding bearing (22d).
Therefore, if the drive shaft (40) rotates, the orbiting scroll
(22) revolves around the axial center of the main shaft portion
(41). The revolution radius of the orbiting scroll (22) is the same
as the eccentricity of the eccentric portion (42), i.e., a distance
from the axial center of the main shaft portion (41) to the axial
center of the eccentric portion (42).
[0081] The orbiting end plate (22a) is disposed in a first recess
(23d) provided to the upper end of the housing (23). The boss (22c)
is disposed in a second recess (a crank chamber) (23e) provided to
the body (23a) of the housing (23). Although not shown, the Oldham
coupling is disposed between the orbiting end plate (22a) and the
housing (23) to prevent the orbiting scroll (22) from rotating on
its axis. The first recess (23d) is formed large enough to allow
the orbiting end plate (22a) to rotate eccentrically, and the
second recess (23e) is formed large enough to allow the boss (22c)
to rotate eccentrically (the size relation therebetween is not
considered on the figures).
[0082] FIG. 2 illustrates the shape of the fixed scroll and the
shape of the orbiting scroll in a cross-section taken along line
II-II of FIG. 1. As shown in FIG. 2, the scroll compressor (1) in
this embodiment has a so-called asymmetrical spiral structure. The
number of turns or windings of the spiral (the length of the
spiral) differs between the fixed lap (21b) and the orbiting lap
(22b). Specifically, the number of turns or windings of the spiral
of the fixed lap (21b) is longer than that of the orbiting lap
(22b) by about a half turn. However, the outermost periphery, i.e.,
the last turn or winding of the fixed lap (21b) has no outer
surface, and the portion of the fixed lap (21b) corresponding to
the outer surface of the outermost periphery is continuous with the
edge portion (21c) of the fixed scroll (21). The spiral of the
fixed lap (21b) is ended such that its outer peripheral end faces
its inner peripheral end longer than the outer peripheral end by
one turn, and is located near the outer peripheral end (turn or
winding end) of the orbiting lap (22b).
[0083] The compression mechanism (20) includes a plurality of
compression chambers (25a, 25b) in a space between the fixed end
plate (21a) and the orbiting end plate (22a). The compression
chambers (25a, 25b) are defined by allowing the fixed lap (21b) to
mesh with the orbiting lap (22b). The plurality of the compression
chambers (25a, 25b) include a plurality of first compression
chambers (25a) and a plurality of second compression chambers
(25b). The first compression chamber (25a) is defined by a space
between the inner peripheral surface of the fixed lap (21b) and the
outer peripheral surface of the orbiting lap (22b). The second
compression chamber (25b) is defined by a space between the outer
peripheral surface of the fixed lap (21b) and the inner peripheral
surface of the orbiting lap (22b). In this embodiment, the number
of turns or windings of the fixed lap (21b) is greater than that of
the orbiting lap (22b), and thus, the maximum capacity of the first
compression chamber (25a) is larger than that of the second
compression chamber (25b).
[0084] As shown in FIGS. 1 and 2, the outer periphery of the fixed
scroll (21) is provided with a suction port (29). This suction port
(29) is open toward a space above the compression mechanism (20).
The suction port (29), along with the revolution of the orbiting
scroll (22), intermittently communicates with the first compression
chamber (25a) and the second compression chamber (25b).
[0085] The upper end of the fixed end plate (21a) is provided with
a depression (21g), and a discharge cover (27) is attached to the
upper surface of the fixed end plate (21a) to cover a depression
(21g). A space where the depression (21g) is covered with the
discharge cover (27) is a discharge chamber (28) communicating with
the discharge pipe (15). A middle lower portion of the fixed end
plate (21a) is provided with a discharge port (26) communicating
with the discharge chamber (28). The discharge port (26), along
with the revolution of the orbiting scroll (22), intermittently
communicates with the first compression chamber (25a) and the
second compression chamber (25b). In this embodiment, in the
interior of the casing (10), both upper and lower spaces (16) and
(17) of the housing (23) are low-pressure spaces filled with a
low-pressure refrigerant.
[0086] In this embodiment, as shown in FIG. 3 that is an enlarged
view of the compression mechanism (20), a suction volume adjustment
mechanism (30) is provided to adjust a suction completion position
of the compression chambers (25a, 25b) in the suction process of
the compression mechanism (20) to adjust the suction volume. This
suction volume adjustment mechanism (30) is configured to adjust
the suction completion position (at which the suction process is
completed and a compression process is started) in both the first
and second compression chambers (25a) and (25b). Only one suction
volume adjustment mechanism (30) is provided to the outer spiral
periphery within one turn, as shown in FIG. 2. The suction volume
adjustment mechanism (30) is configured to adjust the suction
volume by switching the suction completion position of the
compression chambers (25a, 25b) in the suction process between a
first position and a second position in which the suction volume is
smaller than in the first position. The suction volume adjustment
mechanism (30) is an opening/closing mechanism (31) allowing the
first and second compression chambers (25a) and (25b) to switch
between a communicating state and a shut-off state.
[0087] The opening/closing mechanism (31), as shown in FIG. 4
illustrating its cross-sectional structure, specifically includes a
communication passage (32), a plunger (33), and an opening/closing
drive mechanism (34). The communication passage (32) allows the
refrigerant to flow between the first and second compression
chambers (25a) and (25b) when the first and second compression
chambers (25a) and (25b) communicate with each other. The plunger
(33) is switchable between a closed position in which the
communication passage (32) is closed to move the suction completion
position to the first position, and an open position in which the
communication passage (32) is open to move the suction completion
position to the second position. The opening/closing drive
mechanism (34) switches the position of the plunger (33) between
the open position and the closed position.
[0088] As shown in FIG. 5, the plunger (33) is a cylindrical valve
body, and has an outer surface provided with a circumferential
groove (33d) that is disposed on the oil passage (44) in the second
position and is deviated from the oil passage (44) in the first
position.
[0089] The communication passage (32) is a stepped hole (32) formed
in the fixed end plate (21a). As shown in FIGS. 2 and 3, this
stepped hole (32) is formed in the outer periphery of the spiral
within one turn, and in an obliquely lower left position of the
spiral center in the figure. As shown in FIGS. 2 and 3, this
stepped hole (32) is comprised of a larger-diameter portion (32a)
opening toward the upper surface of the fixed end plate (21a), and
a smaller-diameter portion (32b) having a smaller diameter than the
larger-diameter portion (32a). The smaller-diameter portion (32b)
constitutes the communication passage (32). This stepped hole (32)
is formed such that the smaller-diameter portion (32b) is located
between teeth of the fixed lap (21b). The smaller-diameter portion
(32b) is a circular hole having a larger diameter than the
thickness of the tooth of the orbiting lap (22b).
[0090] A compression coil spring (a biasing member) (35) and the
plunger (33) (see FIG. 5) having a tip end for opening/closing the
smaller-diameter portion (32b) are fitted in the stepped hole (32).
As shown in FIG. 5, the plunger (33) includes a plug (33a) fitted
into the smaller-diameter portion (32b), a spring holder (33b)
having a larger diameter than the plug (33a) and mounting the
compression coil spring (35) therein, and a sealing portion (33c)
having a larger diameter than the spring holder (33b), the plug
(33a), the spring holder (33b), and the sealing portion (33a) being
continuously, integrally formed with one another from a tip end
(the lower end of the figure). The sealing portion (33c) is
provided with the circumferential groove (33d).
[0091] As shown in FIGS. 3 and 4, the opening/closing drive
mechanism (34) is comprised of the compression coil spring (35) and
a switching valve (a switching member) (36). The compression coil
spring (35) biases the plunger (33) toward its open position. The
switching valve (36) switches the state of the plunger (33) between
a state in which a low pressure is applied to the plunger (33) and
a state in which a high pressure is applied to the plunger (33)
against the biasing force of the compression coil spring (35). If
the switching valve (36) is switched to apply a low pressure to the
rear end surface (the upper surface) of the plunger (33), a force
of the compression coil spring (35) trying to raise the plunger
(33) is superior to a force trying to depress the plunger (33), and
the communication passage (32) is opened. As a result, the first
compression chamber (25a) communicates with the second compression
chamber (25b). If the switching valve (36) is switched to apply a
high pressure to the rear end surface of the plunger (33), the
force trying to depress the plunger (33) is superior to the force
of the compression coil spring (35) trying to raise the plunger
(33), and the communication passage (32) is closed. As a result,
the first compression chamber (25a) does not communicate with the
second compression chamber (25b).
[0092] Although the specific operation of the suction volume
adjustment mechanism (30) (opening/closing mechanism (31)) will be
described later, if the suction volume adjustment mechanism (30) is
operated with the plunger (33) in the closed position, the first
and second compression chambers (25a) and (25b) do not communicate
with each other. Thus, a normal operation in which the refrigerant
is compressed with a set suction volume is performed. In contrast,
if the suction volume adjustment mechanism (30) is operated with
the plunger (33) in the open position, the first and second
compression chambers (25a) and (25b) communicate with each other.
Thus, an adjustment operation is performed in which the refrigerant
is compressed with a less suction volume than a set value. In this
embodiment, the rotational speed of the electric motor (45) is
faster during this adjustment operation than during the normal
operation.
[0093] In the casing (10), an oil reservoir (50) is formed in the
bottom of the second recess (the crank chamber) (23e) to reserve
oil that has lubricated the bearing of the drive shaft (41) and
other components. The compression mechanism (20) in this embodiment
is provided with an oil passage (51) communicating with the oil
reservoir (50) and a suction space (25s) of the compression
chambers (25a, 25b). The oil passage (51) has one end communicating
with the oil reservoir (50) formed in the crank chamber (23e) in
the housing (23) of the compression mechanism (20), and the other
end communicating with the suction space (25s) of the compression
mechanism (20). The oil passage (51), as shown in FIGS. 3 and 6, is
comprised of a lengthwise passage (52) adjacent to the oil
reservoir, and a transverse passage (an arc-shaped passage) (53)
adjacent to the suction space (25s) of the compression mechanism
(20).
[0094] The plunger (33) is disposed midway of the transverse
passage (53) of the oil passage (51). The plunger (33) includes a
switching portion (55). This switching valve (55) closes the oil
passage (51) in the closed position to allow the oil reservoir (50)
not to communicate with the suction space (25s) of the compression
chambers (25a, 25b), and opens the oil passage (51) in the open
position to allow the oil reservoir (50) to communicate with the
suction space (25s) of the compression chambers (25a, 25b). This
switching portion (55) is configured as the circumferential groove
(33d) formed in the sealing portion (33c). That is to say, in the
open position in FIG. 3, the oil passage (51) communicates with the
oil reservoir (50) and the suction space (25s) of the compression
chambers (25a, 25b) through the circumferential groove (33d). In
contrast, in the closed position which is not shown, the sealing
portion (33c) blocks the oil passage (51), and thus, the oil
reservoir (50) does not communicate with the suction space (25s) of
the compression chambers (25a, 25b), and no oil is supplied from
the oil reservoir (50) to the suction space (25s) of the
compression chambers (25a, 25b).
Operation
[0095] Next, it will be described how the scroll compressor (1)
stated above is operated.
[0096] First, if the electric motor (45) is driven, the drive shaft
(40) rotates and the orbiting scroll (22) revolves relative to the
fixed scroll (21). At that time, the Oldham coupling (not shown)
prevents the fixed scroll (21) from rotating on its axis.
[0097] Along with the revolution of the orbiting scroll (22),
volumes of the compression chambers (25a, 25b) increase and
decrease repeatedly and periodically. In the compression chambers
(25a, 25b), the refrigerant in the refrigerant circuit is sucked
from the suction pipe (14) through a suction passage (not shown)
and the suction port (29) into the compression chambers (25a, 25b)
when the volume of a portion, communicating with the suction port
(29), of the compression chambers (25a, 25b) is increased, and the
refrigerant in the refrigerant circuit is compressed and discharged
from the discharge port (26) to the discharge chamber (28) when the
volume of a portion in which a suction side is closed decreases.
The refrigerant in the discharge chamber (28) is supplied from the
discharge pipe (15) to the condenser in the refrigerant
circuit.
Operation of Compression Mechanism During Normal Operation
[0098] The refrigerant suction and compression operations of the
compression mechanism (20) when the suction volume adjustment
mechanism (30) is not operated (during the normal operation) will
be described with reference to FIGS. 7 to 12. During the normal
operation, the plunger (33) of the opening/closing mechanism (31)
is in the closed position, and closes the communication passage
(32), and the first compression chamber (25a) does not communicate
with the second compression chamber (25b). FIGS. 7 to 12 are
cross-sectional views of six stages of the operation state of the
compression mechanism (20), and illustrate that the orbiting scroll
(22) revolves at a predetermined angle in the clockwise direction
in the figures.
[0099] First, in the first operation state shown in FIG. 7, the
spiral of the orbiting lap (22b) is ended between the teeth of the
fixed lap (21b), and both the first compression chamber (25a-0) and
the second compression chamber (25b-0) which are in the outermost
periphery communicate with a low-pressure side and the suction port
(29). Regarding the first compression chamber (25a), the outer
peripheral surface of the orbiting lap (22b) is substantially in
contact with the inner peripheral surface of the fixed lap (21b) at
the point P on the center line Y of the figure. "Contact" in this
context means a state where, although there is a gap of submicron
order, even if the refrigerant is leaked, no problem occurs because
of formation of the oil film. The compression process is started in
a portion (25a-1) that is in the inner side (a side closer to the
start point of the spiral) relative to the contact point (sealing
point) P1.
[0100] From this state, the orbiting scroll (22) revolves in the
clockwise direction in the figure to be in the second operation
state in FIG. 8. At that time, the inner peripheral surface of the
spiral end of the orbiting lap (22b) is in contact with the outer
peripheral surface of the fixed lap (21b), and its contact point
(sealing point) P2 is the suction completion position of the second
compression chamber (25b-1). At that time, the suction process in
which the volume is increased is still being performed in the first
compression chamber (25a-0) that is in the outermost periphery, and
no sealing point at the spiral end is formed.
[0101] From this state, if the orbiting scroll (22) revolves to be
in the third operation state in FIG. 9, the volume of the second
compression chamber (25b-1) is reduced to start the compression
process of the refrigerant in the second compression chamber
(25b-1), and the volume of the first compression chamber (25a-0)
that is in the outermost periphery is further expanded to allow the
suction process of the refrigerant to proceed in the first
compression chamber (25a-0). In the fourth operation state in FIG.
10, the compression process further proceeds in the second
compression chamber (25b-1), and the suction process further
proceeds in the first compression chamber (25a-0) that is in the
outermost periphery. Regarding the second compression chamber
(25b), the second compression chamber (25b-0) is newly formed at a
portion closer to the turn or winding end of the spiral relative to
the second compression chamber (25b-1) in which the compression
process is being performed, and the suction process is started in
the newly formed second compression chamber (25b-0).
[0102] In the fifth operation state shown in FIG. 11, the suction
process further proceeds in the second compression chamber (25b-0)
that is in the outermost periphery, the outer peripheral surface of
the turn or winding end of the spiral of the orbiting lap (22b) is
in contact with the inner peripheral surface of the fixed lap
(21b), and its contact point (sealing point) P1 is the suction
completion position of the first compression chamber (25a-1). In
the sixth operation state shown in FIG. 12, the compression process
proceeds in the first compression chamber (25a-1) formed in the
state of FIG. 11, and the suction process proceeds in the second
compression chamber (25b-0) that is in the outermost periphery.
Then, the process goes back to the first operation state shown in
FIG. 7, the first compression chamber (25a-0) is newly formed at a
portion closer to the outer periphery (the turn or winding end of
the spiral) of the first compression chamber (25a-1) in which the
compression process is being performed.
[0103] Thereafter, the operations in FIGS. 7 to 12 are repeatedly
performed, the first compression chamber (25a-1) in the middle of
compression and the second compression chamber (25b-1) are moved
toward the inner side of the spiral while reducing its volume, and
the first compression chamber (25a-2) and the second compression
chamber (25b-2) change to the state immediately before the
discharge. When the first compression chamber (25a-2) and the
second compression chamber (25b-2) are moved to the innermost
peripheral side to have the minimum volume, they communicate with
the discharge port (26), and the refrigerant is discharged from the
compression mechanism (20).
[0104] During the normal operation, in the suction volume
adjustment mechanism (30), the plunger (33) is in the closed
position and the oil passage (51) is blocked. As a result, the oil
reservoir (50) does not communicate with the suction space (25s) of
the compression chambers (25a, 25b). Therefore, during the normal
operation at the high operation capacity, the discharge of the oil
is small, and along with this, no oil is supplied from the oil
reservoir (50) to the compression chambers (25a, 25b), and oil is
not excessively supplied to the compression chambers.
Operation of Compression Mechanism During Adjustment Operation
[0105] Likewise, the refrigerant suction and compression operations
of the compression mechanism (20) when the suction volume
adjustment mechanism (30) is operated (during the adjustment
operation) will be described with reference to FIGS. 7 to 12.
During the adjustment operation, in the opening/closing mechanism
(31) that is the suction volume adjustment mechanism (30), the
plunger (33) is in the open position and opens the smaller-diameter
portion (32b) of the communication passage (32). This allows the
first compression chamber (25a) to communicate with the second
compression chamber (25b).
[0106] First, in the first operation state shown in FIG. 7, both
the first compression chamber (25a-0) and the second compression
chamber (25b-0) in the outermost periphery communicate with the
low-pressure side and the suction port (29), which is the same as
the normal operation. During the normal operation, the outer
peripheral surface of the orbiting lap (22b) is in contact with the
inner peripheral surface of the fixed lap (21b) at the point P1 on
the center line Y of the figure, and the first compression chamber
(25a-1) in the inner side (the side closer to the winding start
point of the spiral) relative to the contact point (sealing point)
P1 is already closed. In contrast, the first compression chamber
(25a-1) during this operation communicates with the second
compression chamber (25b-0) that is in the outermost periphery in
the middle of the suction process through the communication passage
(32). Accordingly, the first compression chamber (25a-1) is in a
position prior to the suction completion position, and is in the
middle of the suction process as well as the second compression
chamber (25b).
[0107] In the second operation state in FIG. 8, the contact point
P1 between the inner peripheral surface of the fixed lap (21b) and
the outer peripheral surface of the orbiting lap (22b) is displaced
to a position immediately rearward of the communication passage
(32) of the opening/closing mechanism (31). Therefore, the contact
point (sealing point) P1 at that time is the suction completion
position of the first compression chamber (25a-1). In this
position, the second compression chamber (25b-1) that is located in
the outermost periphery and is closed during the normal operation
communicates with the first compression chamber (25a-0) that is
located in the outermost periphery and is formed in the outside of
the spiral of the first compression chamber (25a-1) that is in the
compression process through the communication passage (32). The
first compression chamber (25a-0) that is located in the outermost
periphery is in the middle of the suction process, and thus, the
second compression chamber (25b) is in a position prior to the
suction completion position.
[0108] This position is also seen in the third operation state
shown in FIG. 9 and the fourth operation state shown in FIG. 10.
The second compression chamber (25b-1) is in the position prior to
the suction completion position, and a sealing point closer to the
turn or winding end is not formed yet. At that time, the first
compression chamber (25a-0) that is the outermost periphery is also
in the middle of the suction process. In the fourth operation state
shown in FIG. 10, the second compression chamber (25b-0) is started
to be newly formed in the outside of the spiral of the second
compression chamber (25b-1).
[0109] In the fifth operation state shown in FIG. 11, the contact
point P2 between the outer peripheral surface of the fixed lap
(21b) and the inner peripheral surface of the orbiting lap (22b)
passes through the communication passage (32) of the
opening/closing mechanism (31). Therefore, the contact point P2 at
that time is the sealing point of the second compression chamber
(25b-1), and the compression process is started in the second
compression chamber (25b-1). In this state, although the suction
process in the first compression chamber (25a-1) that is in the
outermost periphery is completed in the normal operation, the first
compression chamber (25a-1) that is in the outermost periphery in
the adjustment operation communicates with the low-pressure side
through the second compression chamber (25b-0) that is in the
outermost periphery, and thus, is in the middle of the suction
process. This also occurs in the sixth operation state in FIG. 12,
and the same occurs if the process goes back to the first operation
state in FIG. 7.
[0110] As can be seen, the communication passage (32) of the
opening/closing mechanism (31) is opened, and thus, the volume of
the first compression chamber (25a) and the volume of the second
compression chamber (25b) is smaller than during the normal
operation. As a result, a compression ratio is smaller than during
the normal operation, and if its suction pressure is the same as
during the normal operation, the discharge pressure is
decreased.
[0111] During this adjustment operation, the rotational speed of
the electric motor (45) is faster than during the normal operation,
and thus, substantially the same performance of the scroll
compressor (1) as in the normal operation can be achieved.
[0112] During the adjustment operation, in the suction volume
adjustment mechanism (30), the plunger (33) is in the open position
and the oil passage (51) is opened to allow the oil reservoir (50)
to communicate with the suction space (25s) of the compression
chambers (25a, 25b). Therefore, during the adjustment operation at
the low operation capacity, the performance is adjusted to provide
the same capacity, and thus, the rotational speed is faster than in
the case where no adjustment is made. This increases the supply
amount of the oil to the compression chambers (25a, 25b), and in
addition, allows oil from the oil reservoir (18, 50) to the
compression chambers (25a, 25b). As a result, oil is sufficiently
supplied to the compression chambers (25a, 25b).
Advantages of First Embodiment
[0113] According to this embodiment, if only the adjustment
operation at the low operation capacity is performed, oil is not
sufficiently supplied to the compression chambers (25a, 25b), and
the oil film having a thickness necessary for the compression
mechanism (20) is not formed, resulting in performance degradation.
However, if the oil passage (51) is opened and the oil reservoir
(50) communicates with the suction space (25s) of the compression
chambers (25a, 25b), oil is sufficiently supplied to the
compression chambers (25a, 25b). Thus, this can improve performance
during the adjustment operation.
Variation of First Embodiment
[0114] As shown in FIGS. 13 and 14, the oil passage (51) may
include a passage (fixed scroll inner passage (53)) entirely
passing through the inside of the fixed scroll (21) to communicate
with the plunger (33) and the suction space (25s) of the
compression mechanism (20). In this variation, the suction pipe
(14) is connected to the suction port (29), and the transverse
passage (53) of the oil passage (51) communicates with the suction
port (29). Such a configuration allows the oil in the oil reservoir
(50) to mix with the suction refrigerant and to be supplied to the
compression chamber (25).
[0115] According to this variation, if only the adjustment
operation at the low operation capacity is performed, oil is not
sufficiently supplied to the compression chambers (25a, 25b), and
the oil film having a thickness necessary for the compression
mechanism is less likely to be formed, resulting in performance
degradation. However, in this variation, if the oil passage (51) is
in the state in FIG. 13 to be opened and the oil reservoir (50)
communicates with the suction space (25s) of the compression
chambers (25a, 25b), oil is sufficiently supplied to the
compression chambers (25a, 25b). Thus, this can improve performance
during the adjustment operation.
Second Embodiment
[0116] Next, a second embodiment will be described.
[0117] In the second embodiment, as shown in FIGS. 15 and 16, the
oil passage (51) includes an oil passage (55) closer to the
orbiting scroll (hereinafter referred to as "the
orbiting-scroll-side oil passage (55)"), and an oil passage (52)
closer to the fixed scroll (hereinafter referred to as "the
fixed-scroll-side oil passage (52)") communicating with the
orbiting-scroll-side oil passage (55). The orbiting-scroll-side oil
passage (55) has one end communicating with the fixed-scroll-side
oil passage (51), and the other end opposite to one end and
communicating with the oil reservoir (18). Specifically, the end of
the orbiting-scroll-side oil passage (55), which is opposite to one
end communicating with the fixed-scroll-side oil passage (52),
communicates with the oil reservoir (18) in the lower portion of
the casing (10) through the oil supply passage (44) formed inside
the drive shaft (41). An end of the fixed-scroll-side oil passage
(52), which is opposite to an end communicating with the
orbiting-scroll-side oil passage (55), communicates with the
suction space (25s) of the compression mechanism (20).
[0118] According to this second embodiment, if only the adjustment
operation at the low operation capacity is performed, oil is not
sufficiently supplied to the compression chambers (25a, 25b), and
the oil film having a thickness necessary for the compression
mechanism is less likely to be formed, resulting in performance
degradation. However, in the second embodiment, if the oil passage
(51) is in the state in FIG. 16 to be opened and the oil reservoir
(18) communicates with the suction space (25s) of the compression
chambers (25a, 25b), oil is sufficiently supplied to the
compression chambers (25a, 25b). Thus, this can improve performance
during the adjustment operation.
Third Embodiment
[0119] Next, a third embodiment will be described.
[0120] In the third embodiment, as shown in FIG. 17, the oil
passage (51) has one end communicating with the oil reservoir (18)
formed inside the casing (10), and the other end communicating with
the suction space (25s) of the compression mechanism (20).
Specifically, the oil passage (51) has an oil supply pipe (56)
extending upward from the oil reservoir (18) inside the casing (10)
and communicating with the plunger (33). This oil supply pipe (56)
communicates with the transverse passage (53). In the oil passage
(51), a space (the transverse passage (53)) between the plunger
(33) and a suction side of the compression chamber (25) is the same
as, or similar to, that of the variation of the first embodiment
and the second embodiment.
[0121] The other configuration of this embodiment is the same as,
or similar to, that of the second embodiment.
[0122] According to this third embodiment, if only the adjustment
operation at the low operation capacity is performed, oil is not
sufficiently supplied to the compression chambers (25a, 25b), and
the oil film having a thickness necessary for the compression
mechanism is less likely to be formed, resulting in performance
degradation. However, in the third embodiment, if the oil passage
(51) is in the state in FIG. 17 to be opened and the oil reservoir
(18) communicates with the suction space (25s) of the compression
chambers (25a, 25b), oil is sufficiently supplied to the
compression chambers (25a, 25b). Thus, this can improve performance
during the adjustment operation.
Fourth Embodiment
[0123] Next, a fourth embodiment will be described.
[0124] In the fourth embodiment, as shown in FIG. 18, the oil
passage (51) has one end communicating with an oil supply pump
(43a) provided to the drive shaft (41), and the other end
communicating with the suction space (25s) of the compression
mechanism (20). Specifically, the oil passage (51) has an oil
supply pipe (57) extending upward from the oil supply pump (43a)
provided to the lower end of the drive shaft (41) and communicating
with the plunger (33). This oil supply pipe (57) communicates with
the transverse passage (53). In the oil passage (51), a space (the
transverse passage (53)) between the plunger (33) and a suction
side of the compression chamber (25) is the same as, or similar to,
that of the variation of the first embodiment and the second
embodiment.
[0125] The other configuration of this embodiment is the same as,
or similar to, that of the third embodiment.
[0126] According to this fourth embodiment, if only the adjustment
operation at the low operation capacity is performed, oil is not
sufficiently supplied to the compression chambers (25a, 25b), and
the oil film having a thickness necessary for the compression
mechanism is less likely to be formed, resulting in performance
degradation. However, in the fourth embodiment, if the oil passage
(51) is in the state in FIG. 18 to be opened and the oil reservoir
(18) communicates with the suction space (25s) of the compression
chambers (25a, 25b), oil is sufficiently supplied to the
compression chambers (25a, 25b). Thus, this can improve performance
during the adjustment operation.
Fifth Embodiment
[0127] Next, a fifth embodiment will be described.
[0128] In the fifth embodiment, as shown in FIGS. 19 to 21, the oil
passage (51) includes a fixed scroll outer passage (58) passing
through the space (17) formed outside the fixed scroll (21) inside
the casing (10) to communicate with the plunger (33) and the
suction space (25s) of the compression mechanism (20). In the fifth
embodiment, the fixed scroll (21) is provided with a gas discharge
passage (60) through which the refrigerant gas is discharged from
the compression chambers (25a, 25b) to the space (17).
[0129] According to this configuration, as shown in FIG. 20, when
the plunger (33) is open, the refrigerant gas is discharged from
the compression chambers and oil is also discharged from the
transverse passage (53) to the space (17). The refrigerant gas and
the oil are mixed with each other and sucked into the suction space
(25s). In contrast, as shown in FIG. 21, when the plunger (33) is
closed, no refrigerant gas is discharged from the compression
chambers (25a, 25b) to the space (17), and no oil is discharged
from the transverse passage (53) to the space (17).
[0130] According to this fifth embodiment, if only the adjustment
operation at the low operation capacity is performed, oil is not
sufficiently supplied to the compression chambers (25a, 25b), and
the oil film having a thickness necessary for the compression
mechanism is less likely to be formed, resulting in performance
degradation. However, in the fifth embodiment, if the oil passage
(51) is in the state in FIG. 20 to be opened and the oil reservoir
(18) communicates with the suction space (25s) of the compression
chambers (25a, 25b), oil is sufficiently supplied to the
compression chambers (25a, 25b). Thus, this can improve performance
during the adjustment operation. The high speed operation can
reduce performance degradation and oil loss.
Sixth Embodiment
[0131] A sixth embodiment of the present disclosure is an example
and has the same configuration as the fifth embodiment, except the
configuration for the oil passage (51). Specifically, as shown in
FIGS. 22 and 23, the oil passage (51) includes a fixed scroll outer
passage (58) passing through the space (17) formed outside the
fixed scroll (21) inside the casing (10) to communicate with the
plunger (33) and the suction space (25s) of the compression
mechanism (20). In the sixth embodiment, the fixed scroll (21) is
provided with a gas discharge passage (60) through which the
refrigerant gas is discharged from the compression chambers (25a,
25b) to the space (17). In this sixth embodiment, the end of the
transverse passage (53) is closed and the transverse passage (53)
communicates with the gas discharge passage (60) through an oil mix
passage (53a).
[0132] According to this configuration, as shown in FIG. 23, when
the plunger (33) is open, the refrigerant gas is discharged from
the compression chambers, and the oil is mixed with the gas flowing
through the gas discharge passage (60) to be discharged into the
space (17). The refrigerant gas and the oil are mixed together, and
are sucked into the suction space (25s). Although not shown, when
the plunger (33) is closed, no gas is discharged from the
compression chambers (25a, 25b) into the space (17).
[0133] According to this sixth embodiment, if only the adjustment
operation at the low operation capacity is performed, oil is not
sufficiently supplied to the compression chambers (25a, 25b), and
the oil film having a thickness necessary for the compression
mechanism is less likely to be formed, resulting in performance
degradation. However, in the sixth embodiment, if the oil passage
(51) is in the state in FIG. 23 to be opened and the oil reservoir
(18) communicates with the suction space (25s) of the compression
chambers (25a, 25b), oil is sufficiently supplied to the
compression chambers (25a, 25b). Thus, this can improve performance
during the adjustment operation.
Other Embodiments
[0134] The above-described embodiment may be modified as
follows.
[0135] For example, the above embodiments are the examples where
the present disclosure is applied to the asymmetrical spiral
structure. The present disclosure may also be applied to a scroll
compressor having a symmetrical spiral structure. In this case, the
suction volume adjustment mechanism (30) having the same or similar
configuration as or to those in the above embodiments may be
provided to each symmetrical position relative to the center of the
spiral. Such a configuration allows the compression mechanism (20)
having the symmetrical spiral structure to adjust the suction
completion positions of the first and second compression chambers
(25a) and (25b) relative to the center of the spiral, while
controlling the flow of the oil. As a result, the same or similar
advantages in the above embodiments can also be obtained.
[0136] In the above embodiments, the present disclosure is applied
to the scroll compressor. However, the present disclosure is not
limited to the scroll compressor. For example, the present
disclosure may also be applied to a rolling piston compressor or an
oscillating piston compressor.
[0137] Further, in the above embodiments, as shown in FIG. 24, a
sealing member (33e) may be provided to both sides of the
circumferential groove (33d) in the outer peripheral surface of the
plunger (33). In this case, the sealing portion (33c) of the
plunger (33) has a sealing mount groove (33f) at both sides of the
circumferential groove (33d) in the circumferential direction, and
the ring-shaped sealing member (33e) is mounted on the sealing
mount groove (33f).
[0138] Note that the foregoing description of the embodiments is a
merely preferred example in nature, and is not intended to limit
the scope, application, or uses of the present disclosure.
INDUSTRIAL APPLICABILITY
[0139] As can be seen from the foregoing description, the present
disclosure is useful for, in a compressor including a suction
bypass mechanism configured to change a suction completion position
to adjust a suction volume, a technique of solving lubricant
shortage in a compression mechanism.
DESCRIPTION OF REFERENCE CHARACTERS
[0140] 1 Scroll Compressor [0141] 10 Casing [0142] 18 Oil Reservoir
[0143] 21 Fixed Scroll [0144] 22 Orbiting Scroll [0145] 23 Housing
[0146] 23e Crank Chamber [0147] 25a Compression Chamber [0148] 25b
Compression Chamber [0149] 25s Suction Space [0150] 30 Suction
Volume Adjustment Mechanism [0151] 33 Plunger [0152] 33d
Circumferential Groove [0153] 33e Sealing Member [0154] 43a Oil
Supply Pump [0155] 50 Oil Reservoir [0156] 51 Oil Passage [0157] 52
Fixed-scroll-side Oil Passage (Fixed Scroll Inner Passage) [0158]
53 Fixed-scroll-side Oil Passage (Fixed Scroll Inner Passage)
[0159] 53a Oil Mix Passage [0160] 55 Orbiting-scroll-side Oil
Passage [0161] 56 Oil Supply Pipe [0162] 57 Oil Supply Pipe [0163]
58 Fixed Scroll Outer Passage [0164] 60 Gas Discharge Passage
[0165] 65 Switching Portion
* * * * *