description
FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
SCROLL COMPRESSOR AND REFRIGERATION CYCLE APPARATUS;
MITSUBISHI ELECTRIC CORPORATION, A CORPORATION ORGANISED AND
EXISTING UNDER THE LAWS OF JAPAN, WHOSE ADDRESS IS 7-3,
MARUNOUCHI 2-CHOME, CHIYODA-KU, TOKYO 100-8310, JAPAN
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION
AND THE MANNER IN WHICH IT IS TO BE PERFORMED.
2
DESCRIPTION
Title of Invention
SCROLL COMPRESSOR AND REFRIGERATION CYCLE APPARATUS
5 Technical Field
[0001]
The present disclosure relates to a scroll compressor having an injection port,
and to a refrigeration cycle apparatus.
Background Art
10 [0002]
There is a conventionally-known scroll compressor in which injection refrigerant
is supplied to a compression chamber formed by combining a fixed spiral body of a
fixed scroll and an orbiting spiral body of an orbiting scroll (see Patent Literature 1, for
example). In the scroll compressor disclosed in Patent Literature 1, of a first
15 compression chamber and a second compression chamber, only injection into the first
compression chamber is performed, the first compression chamber being formed by
the outwardly facing surface of the orbiting spiral body and the inwardly facing surface
of the fixed spiral body, the second compression chamber being formed by the
inwardly facing surface of the orbiting spiral body and the outwardly facing surface of
20 the fixed spiral body.
Citation List
Patent Literature
[0003]
Patent Literature 1: International Publication No. WO 2017/141342
25 Summary of Invention
Technical Problem
[0004]
In the scroll compressor disclosed in Patent Literature 1, only injection into the
first compression chamber is performed, and injection into the second compression
3
chamber is not performed. Such a configuration has a problem that a high injection
flow rate cannot be obtained.
[0005]
The present disclosure has been made in view of the above, and it is an object
5 of the present disclosure to provide a scroll compressor and a refrigeration cycle
apparatus that can perform injection into both the first compression chamber and the
second compression chamber, thus obtaining a high injection flow rate.
Solution to Problem
[0006]
10 A scroll compressor according to an embodiment of the present disclosure
includes a compression mechanism unit including a fixed scroll and an orbiting scroll,
the fixed scroll including a fixed base plate and a fixed spiral body provided on the
fixed base plate, the orbiting scroll including an orbiting base plate and an orbiting
spiral body provided on the orbiting base plate, the compression mechanism unit
15 being configured to cause the orbiting scroll to perform a revolving motion relative to
the fixed scroll to compress refrigerant in a compression chamber formed by
combining the fixed spiral body and the orbiting spiral body, wherein the compression
mechanism unit has an asymmetric spiral structure in which a spiral length of the
fixed spiral body of the fixed scroll differs from a spiral length of the orbiting spiral
20 body of the orbiting scroll, and an injection port is formed in the fixed base plate,
injection refrigerant being supplied to the compression chamber through the injection
port, the compression chamber has a first compression chamber and a second
compression chamber, the first compression chamber being formed by an outwardly
facing surface of the orbiting spiral body and an inwardly facing surface of the fixed
25 spiral body, the second compression chamber being formed by an inwardly facing
surface of the orbiting spiral body and an outwardly facing surface of the fixed spiral
body, and to allow the injection port to communicate with the first compression
chamber within a range of a revolution angle of the orbiting scroll different from a
range of a revolution angle of the orbiting scroll at which the injection port
30 communicates with the second compression chamber, the injection port is formed
4
within a range from a position inward of the inwardly facing surface of the fixed spiral
body by an amount corresponding to a wrap thickness of the orbiting spiral body to a
position outward of the outwardly facing surface of the fixed spiral body by the
amount corresponding to the wrap thickness of the orbiting spiral body, the injection
5 port being formed at a position at which the injection port communicates with the
second compression chamber when suction of refrigerant is completed and a
compression process is about to be started.
Advantageous Effects of Invention
[0007]
10 According to the scroll compressor of the embodiment of the present disclosure,
the injection port is formed within the range from the position inward of the inwardly
facing surface of the fixed spiral body by the amount corresponding to the wrap
thickness of the orbiting spiral body to the position outward of the outwardly facing
surface of the fixed spiral body by the amount corresponding to the wrap thickness of
15 the orbiting spiral body. With such a configuration, it is possible to perform injection
into both the first compression chamber and the second compression chamber.
Further, the injection port is formed at a position at which the injection port
communicates with the second compression chamber when suction of refrigerant is
completed and the compression process is about to be started. With such a
20 configuration, in performing injection into both the first compression chamber and the
second compression chamber, injection into the second compression chamber is
performed prior to injection into the first compression chamber in the asymmetric
spiral structure, the pressure in the second compression chamber being lower than
the pressure in the first compression chamber. As a result of the above, it is
25 possible to obtain a high injection flow rate.
Brief Description of Drawings
[0008]
[Fig. 1] Fig. 1 is a longitudinal cross-sectional schematic view showing a scroll
compressor according to Embodiment 1.
30 [Fig. 2] Fig. 2 is a partial enlarged view of Fig. 1.
5
[Fig. 3] Fig. 3 is a diagram illustrating a flow passage formed between a guide
frame and a sealed container of the scroll compressor according to Embodiment 1.
[Fig. 4] Fig. 4 is a schematic cross-sectional view of a compression mechanism
unit of the scroll compressor according to Embodiment 1
5 [Fig. 5] Fig. 5 is a diagram of a compression process showing actions of an
orbiting scroll of the scroll compressor according to Embodiment 1 during rotation.
[Fig. 6] Fig. 6 is a diagram illustrating details of the actions (injection of
refrigerant and bleeding from a bleed hole) in respective compression chambers
according to a revolution angle in the compression process of the scroll compressor
10 according to Embodiment 1.
[Fig. 7] Fig. 7 is a schematic configuration diagram of a refrigeration cycle
apparatus according to Embodiment 1.
Description of Embodiments
[0009]
15 Embodiment 1.
Fig. 1 is a longitudinal cross-sectional schematic view showing a scroll
compressor according to Embodiment 1. Fig. 2 is a partial enlarged view of Fig. 1.
Fig. 3 is a diagram illustrating a flow passage formed between a guide frame and a
sealed container of the scroll compressor according to Embodiment 1. Hereinafter,
20 the configuration of the scroll compressor 100 will be described with reference to Fig.
1 to Fig. 3.
[0010]
The scroll compressor 100 is what is called a vertical scroll compressor, and
the Z direction being the up and down direction in Fig. 1 is the axial direction of the
25 scroll compressor 100. The scroll compressor 100 compresses and discharges
refrigerant being working gas. An R407C refrigerant, an R410A refrigerant, or an
R32 refrigerant, for example, is used for refrigerant. The scroll compressor 100
includes a sealed container 1, a compression mechanism unit 2 including a fixed
scroll 4 and an orbiting scroll 3, an electric motor 16, and a drive shaft 19. The scroll
30 compressor 100 is configured such that the compression mechanism unit 2, the
6
electric motor 16, and the drive shaft 19 are accommodated in the sealed container 1.
The scroll compressor 100 is one of constitutional elements of a refrigeration cycle
used in various industrial machines, such as refrigerators, freezers, air-conditioning
apparatuses, freezing devices or water heaters. As will be described later, gas
5 refrigerant is compressed by the compression mechanism unit 2, thus becoming gas
refrigerant at high pressure, and is then discharged into a high-pressure gas
atmosphere 6 in the sealed container 1. In this mechanism, this gas refrigerant
cycles through a refrigeration cycle in which the scroll compressor 100 is incorporated.
[0011]
10 The sealed container 1 is formed into a cylindrical shape, for example, and has
a pressure resistance. A suction pipe 7 is connected to the side surface of the
sealed container 1 to take refrigerant into the sealed container 1. A suction check
valve 9 and a spring 10 are disposed in the suction pipe 7. The suction check valve
9 is biased by the spring 10 in the direction in which the suction pipe 7 is closed, thus
15 preventing back flow of refrigerant. In addition to the above, a discharge pipe 11 and
an injection pipe 50 are connected to the side surface of the sealed container 1 at
other positions, compressed refrigerant being released to the outside from the sealed
container 1 through the discharge pipe 11, injection refrigerant being supplied to the
compression mechanism unit 2 from the outside through the injection pipe 50.
20 Arrows in the suction pipe 7 and the discharge pipe 11 show the directions in which
refrigerant flows.
[0012]
The sealed container 1 has the high-pressure gas atmosphere 6 in the sealed
container 1. The bottom portion of the sealed container 1 is an oil reservoir space 5
25 for storing refrigerating machine oil (hereinafter referred to as oil). The oil reservoir
space 5 is a space located within the high-pressure gas atmosphere 6 at a position
lower than a sub-frame 37, which supports the lower end portion of the drive shaft 19,
lower than a sub-bearing 27, which is provided on the sub-frame 37, and lower than
the end portion of the drive shaft 19, for example.
30 [0013]
7
The compression mechanism unit 2 compresses refrigerant suctioned into the
sealed container 1 from the suction pipe 7. The compression mechanism unit 2
includes the orbiting scroll 3 and the fixed scroll 4. As shown in Fig. 1, the fixed
scroll 4 is disposed on the upper side, and the orbiting scroll 3 is disposed on the
5 lower side. The fixed scroll 4 includes a fixed base plate 4b and a fixed spiral body
4a formed on the fixed base plate 4b. The orbiting scroll 3 includes an orbiting base
plate 3b and an orbiting spiral body 3a formed on the orbiting base plate 3b.
[0014]
The fixed scroll 4 and the orbiting scroll 3 are disposed such that the fixed
10 spiral body 4a and the orbiting spiral body 3a face each other. The fixed spiral body
4a and the orbiting spiral body 3a are combined with each other from opposite
directions, thus forming a compression chamber 2b between the fixed spiral body 4a
and the orbiting spiral body 3a. A base plate outer peripheral space (hereinafter
referred to as suction-side space 8) is formed outside the fixed spiral body 4a of the
15 fixed scroll 4 and the orbiting scroll 3, and is a low pressure space of a suction gas
atmosphere of suction pressure.
[0015]
The fixed scroll 4 is fixed to a guide frame 30 by bolts (not shown in the
drawing) or the like, the guide frame 30 being fixed to and supported by the sealed
20 container 1. A pair of two fixed-side Oldham ring grooves 15a are formed on the
outer peripheral portion of the fixed scroll 4 on one straight line. A pair of two fixedside keys 42a of an Oldham ring 40 are installed in the fixed-side Oldham ring
grooves 15a in a reciprocally slidable manner.
[0016]
25 A cylindrical boss portion 3c is formed on the other surface of the orbiting base
plate 3b of the orbiting scroll 3, the other surface being on a side opposite to one
surface of the orbiting base plate 3b on which the orbiting spiral body 3a is formed.
An orbiting bearing 26 is provided on the inner surface of the boss portion 3c. An
orbiting shaft 21 of the drive shaft 19 is inserted into the orbiting bearing 26, and the
8
orbiting scroll 3 performs a revolving motion relative to the fixed scroll 4 due to the
rotation of the orbiting shaft 21.
[0017]
A compliant frame 31 is disposed on the other surface of the orbiting base plate
5 3b of the orbiting scroll 3 in a contact manner. A thrust surface 3d is formed on the
other surface of the orbiting base plate 3b of the orbiting scroll 3, the thrust surface 3d
being slidable on a thrust surface 33 of the compliant frame 31. A pair of two
orbiting-side Oldham ring grooves 15b are formed at the outer peripheral portion of
the orbiting scroll 3 on one straight line. The orbiting-side Oldham ring groove 15b
10 has a phase difference of approximately 90 degrees relative to the fixed-side Oldham
ring groove 15a, and a pair of two orbiting-side keys 42b of the Oldham ring 40 are
installed in the orbiting-side Oldham ring grooves 15b in a reciprocally slidable
manner. Each orbiting-side key 42b reciprocally slides on a reciprocal sliding
surface 41 formed at the outer peripheral portion of the thrust surface 33 of the
15 compliant frame 31.
[0018]
A bleed hole 3e is formed in the orbiting base plate 3b in such a way as to
penetrates through the orbiting base plate 3b from one surface of the orbiting base
plate 3b, on which the orbiting spiral body 3a is provided, to the other surface of the
20 orbiting base plate 3b. As shown in Fig. 2 the bleed hole 3e has a bleed inlet 3ei
and a bleed outlet 3eo, the bleed inlet 3ei being formed on the upper surface, that is,
one surface, of the orbiting base plate 3b, the bleed outlet 3eo being formed on the
lower surface, that is, the other surface, of the orbiting base plate 3b. The bleed inlet
3ei is open to the compression chamber 2b. The bleed outlet 3eo intermittently
25 communicates with a gas introduction passage 14 provided in the compliant frame 31.
The bleed outlet 3eo intermittently communicates with the gas introduction passage
14, so that gas refrigerant at intermediate pressure in the course of compression in
the compression chamber 2b is introduced into an intermediate pressure space 32b
through the bleed hole 3e and the gas introduction passage 14. An intermediate
30 pressure refers to a pressure higher than the suction pressure and lower than the
9
discharge pressure. As described above, with the revolving motion of the orbiting
scroll 3, the bleed hole 3e intermittently bleeds refrigerant into the intermediate
pressure space 32b from the compression chamber 2b in the course of compression.
[0019]
5 In the sealed container 1, the guide frame 30 is disposed above the electric
motor 16, and the sub-frame 37 that holds the drive shaft 19 is disposed below the
electric motor 16. The guide frame 30 and the sub-frame 37 are fixed to the sealed
container 1. The compliant frame 31 is housed on the inner peripheral side of the
guide frame 30.
10 [0020]
A flow passage 30c is formed between the outer peripheral surface of the guide
frame 30 and the inner wall of the sealed container 1, gas refrigerant at high pressure
that flows out from a discharge port 12 formed in the fixed scroll 4 flowing through the
flow passage 30c (see Fig. 1 and Fig. 3). The gas refrigerant at high pressure that
15 flows out from the discharge port 12 is introduced to an area below the compression
mechanism unit 2 through the flow passage 30c. The gas refrigerant at high
pressure is introduced to the area below the compression mechanism unit 2, so that
the high-pressure gas atmosphere 6 is formed in the sealed container 1.
[0021]
20 An upper fitting cylindrical surface 30a is formed on the inner peripheral surface
of the guide frame 30 at a position close to the fixed scroll 4 (at a position close to the
upper side in Fig. 1). The upper fitting cylindrical surface 30a engages with an upper
fitting cylindrical surface 35a formed on the outer peripheral surface of the compliant
frame 31. In contrast, a lower fitting cylindrical surface 30b is formed on the inner
25 peripheral surface of the guide frame 30 at a position close to the electric motor 16 (at
a position close to the lower side in Fig. 1). The lower fitting cylindrical surface 30b
engages with a lower fitting cylindrical surface 35b formed on the outer peripheral
surface of the compliant frame 31.
[0022]
10
An upper annular sealing part 36a and a lower annular sealing part 36b are
disposed on the outer peripheral surface of the compliant frame 31 at two positions.
The upper annular sealing part 36a and the lower annular sealing part 36b divide a
space formed between the inner surface of the guide frame 30 and the outer surface
5 of the compliant frame 31. The space divided by the upper annular sealing part 36a
and the lower annular sealing part 36b forms the intermediate pressure space 32b.
In Fig. 1, the upper annular sealing part 36a and the lower annular sealing part 36b
are disposed on the outer peripheral surface of the compliant frame 31 at two
positions. However, the positions of these sealing parts are not limited to the
10 positions in the example shown in Fig. 1. These sealing parts may be disposed on
the inner peripheral surface of the guide frame 30 at two positions, for example.
[0023]
The compliant frame 31 supports the orbiting scroll 3 in the axial direction.
The compliant frame 31 has the thrust surface 33 that supports, in the axial direction,
15 a thrust force acting in the axial direction of the orbiting scroll 3. The gas
introduction passage 14 is formed in the compliant frame 31, the gas introduction
passage 14 making the thrust surface 33 and the intermediate pressure space 32b
communicate with each other. The gas introduction passage 14 communicates with
the bleed hole 3e in response to the revolving motion of the orbiting scroll 3. When
20 the gas introduction passage 14 communicates with the bleed hole 3e, refrigerant at
intermediate pressure is introduced into the intermediate pressure space 32b from the
compression chamber 2b in the course of compression. In contrast, when the bleed
hole 3e faces the thrust surface 33 of the compliant frame 31, thus being closed in
response to the revolving motion of the orbiting scroll 3, introduction of refrigerant at
25 intermediate pressure into the intermediate pressure space 32b is stopped.
Communication of the bleed hole 3e with the gas introduction passage 14 and closure
of the bleed hole 3e by the thrust surface 33 are repeated as described above, so that
gas refrigerant at intermediate pressure is intermittently introduced into the
intermediate pressure space 32b from the compression chamber 2b. Gas refrigerant
30 at intermediate pressure is intermittently introduced into the intermediate pressure
11
space 32b, so that the intermediate pressure space 32b assumes an intermediate
pressure.
[0024]
The compliant frame 31 supports the orbiting scroll 3 in the axial direction due
5 to the intermediate pressure in the intermediate pressure space 32b. The
intermediate pressure in the intermediate pressure space 32b acts on the compliant
frame 31. A high pressure caused by the high-pressure gas atmosphere 6 acts on a
compliant frame lower end surface 34. The compliant frame 31 is lifted in the axial
direction due to these pressures acting on the compliant frame 31, thus having an
10 effect of pushing up the orbiting scroll 3 in the axial direction.
[0025]
A boss portion outer space 38 at intermediate pressure is provided between the
outer portion of the boss portion 3c of the orbiting scroll 3 and the compliant frame 31.
Further, an intermediate pressure regulating valve space 39d is provided in the
15 compliant frame 31. An intermediate pressure regulating valve 39a, an intermediate
pressure regulating valve retainer 39b, and an intermediate pressure regulating
spring 39c are housed in the intermediate pressure regulating valve space 39d, the
intermediate pressure regulating valve 39a regulating the pressure in the boss portion
outer space 38. The intermediate pressure regulating spring 39c is housed in the
20 intermediate pressure regulating valve space 39d in a contracted state shorter than
the natural length of the intermediate pressure regulating spring 39c.
[0026]
A through passage 39e is also provided in the compliant frame 31, the through
passage 39e making the boss portion outer space 38 and the intermediate pressure
25 regulating valve space 39d communicate with each other. A compliant frame upper
space 32a is provided between the inner peripheral surface of the guide frame 30 and
the outer peripheral surface of the compliant frame 31 at a position closer to the fixed
scroll (at a position closer to the upper side in Fig. 1) than the intermediate pressure
regulating valve space 39d, the compliant frame upper space 32a communicating
30 with the intermediate pressure regulating valve space 39d. The compliant frame
12
upper space 32a is formed in such a way as to communicate with a space located on
the inner side of the Oldham ring 40. Accordingly, the boss portion outer space 38
and the space located on the inner side of the Oldham ring 40 communicate with
each other via the through passage 39e, the intermediate pressure regulating valve
5 space 39d, and the compliant frame upper space 32a.
[0027]
The electric motor 16 rotationally drives the drive shaft 19. The electric motor
16 is configured such that an operating frequency can be controlled by an inverter
device, for example. The electric motor 16 includes an electric motor rotor 16a and
10 an electric motor stator 16b, and generates a rotational force with a variable rotation
speed. The electric motor rotor 16a is fixed to the drive shaft 19 by shrink fitting or
the like. A plurality of through passages penetrating through the electric motor rotor
16a in the axial direction (not shown in the drawing) are formed in the electric motor
rotor 16a at symmetrical or point symmetrical positions relative to the axis of the
15 electric motor rotor 16a.
[0028]
The electric motor stator 16b is connected to a glass terminal (not shown in the
drawing), which is fixed to the guide frame 30, via a lead wire (not shown in the
drawing) to obtain power from the outside. The electric motor stator 16b is fixed to
20 the sealed container 1 by shrink fitting or the like, and a through passage (not shown
in the drawing) formed by a notch is formed at the outer peripheral portion of the
electric motor stator 16b. When power is supplied to the electric motor stator 16b,
the drive shaft 19 and the electric motor rotor 16a rotate relative to the electric motor
stator 16b. For keeping balance of the entire rotation system of the scroll
25 compressor 100, balance weights 18a are fixed to the electric motor rotor 16a, and a
balance weight 18b is fixed to the drive shaft 19.
[0029]
The drive shaft 19 includes the orbiting shaft 21, a main shaft 20, and a subshaft 22, the orbiting shaft 21 forming the upper portion of the drive shaft 19, the main
30 shaft 20 forming the intermediate portion of the drive shaft 19, the sub-shaft 22
13
forming the lower portion of the drive shaft 19. The main shaft 20 is rotatably
supported by a main bearing 25 provided on the inner peripheral surface of the
compliant frame 31. The sub-shaft 22 is rotatably supported by the sub-bearing 27
provided on the inner peripheral surface of the sub-frame 37. The own weight of the
5 lower end surface of the sub-shaft 22 is supported by a thrust bearing 28. The thrust
bearing 28 is fixed to a holder 29, and the holder 29 is fixed to the sub-frame 37.
Each of the main bearing 25 and the sub-bearing 27 has a cylindrical structure, and
has a bearing structure that is formed by a sliding bearing made of a copper-lead alloy,
for example. The main bearing 25 and the sub-bearing 27 pivotally supports the
10 drive shaft 19 in a rotatable manner.
[0030]
The drive shaft 19 transmits a rotational force generated by the electric motor
16 to the compression mechanism unit 2. An oil supply passage 23 and supply
passages 24a and 24b are formed in the drive shaft 19, the oil supply passage 23
15 extending in the axial direction from the end portion of the drive shaft 19, the supply
passages 24a and 24b extending in the radial direction from the oil supply passage
23. The supply passage 24a is formed in the sub-shaft 22, and the supply passage
24b is formed in the main shaft 20. Oil suctioned from the oil reservoir space 5
passes through the oil supply passage 23, the supply passage 24a, and the supply
20 passage 24b, and is supplied to respective sliding portions, such as the main bearing
25, the orbiting bearing 26, and the sub-bearing 27. That is, the oil supply passage
23 is open at the upper end portion of the drive shaft 19 in the axial direction, and
supplies oil to the orbiting bearing 26. The supply passage 24b is open at a position
covered by the main bearing 25, and supplies oil to the main bearing 25. The supply
25 passage 24a formed in the sub-shaft 22 is open at a position covered by the subshaft 22, and supplies oil to the sub-shaft 22. In Fig. 1, arrows in the oil supply
passage 23 and the supply passages 24a and 24b show the flow of oil.
[0031]
Next, an injection mechanism that supplies injection refrigerant to the
30 compression mechanism unit 2 will be described.
14
An injection inflow passage 4d and an injection port 4e are formed in the fixed
base plate 4b of the fixed scroll 4, the injection port 4e communicating with the
injection inflow passage 4d. The end portion of the injection pipe 50 is connected to
the injection inflow passage 4d, the injection pipe 50 penetrating through the sealed
5 container 1. The injection port 4e is open on one surface of the fixed base plate 4b
on which the fixed spiral body 4a is formed. The injection port 4e supplies, to the
compression chamber 2b, injection refrigerant that is supplied through the injection
inflow passage 4d from the injection pipe 50.
[0032]
10
(On startup and when injection is OFF)
The action of the scroll compressor 100 when the scroll compressor 100 is
started up and when injection is OFF will be described. When gas refrigerant at low
pressure (suction pressure) is supplied from the suction pipe 7 toward the suction
15 check valve 9, the gas refrigerant overcomes the spring force of the spring 10, thus
pushing back the suction check valve 9 to a valve stop (not shown in the drawing).
The suction check valve 9 is thus opened, so that the gas refrigerant flows into the
suction-side space 8 in the sealed container 1.
[0033]
20 In contrast, the drive shaft 19 starts to rotate when power is supplied to the
electric motor 16 from the outside. The rotation of the drive shaft 19 causes the
orbiting shaft 21 to rotate, so that the orbiting scroll 3 performs an oscillating motion
(revolving motion). At this point of operation, gas refrigerant is suctioned into the
compression chamber 2b formed between the orbiting scroll 3 and the fixed scroll 4.
25 [0034]
Due to a geometric change in the volume of the compression chamber 2b, the
gas refrigerant is eventually increased in pressure from a low pressure to a high
pressure. Thereafter, the gas refrigerant, the pressure of which is increased to a
high pressure, is discharged from the discharge port 12, passes through the flow
30 passage 30c, and is then introduced to the area below the guide frame 30. Due to
15
the gas refrigerant introduced to the area below the guide frame 30, the inside of the
sealed container 1 assumes the high-pressure gas atmosphere 6. The gas
refrigerant at high pressure in the sealed container 1 is discharged to the outside from
the discharge pipe 11.
5 [0035]
The bleed outlet 3eo of the bleed hole 3e formed in the orbiting base plate 3b
temporarily communicates with the gas introduction passage 14 due to the revolving
motion of the orbiting scroll 3. When the bleed outlet 3eo of the bleed hole 3e
temporarily communicates with the gas introduction passage 14, gas refrigerant at
10 intermediate pressure in the course of compression in the compression chamber 2b
communicating with the bleed hole 3e is caused to bleed to the outside of the
compression chamber 2b, and is then introduced into the intermediate pressure
space 32b through the gas introduction passage 14. Temporary communication of
the bleed hole 3e with the gas introduction passage 14 is intermittently made during
15 the revolving motion of the orbiting scroll 3.
[0036]
The intermediate pressure space 32b is a space sealed by the upper annular
sealing part 36a and the lower annular sealing part 36b. Therefore, the compliant
frame 31 is lifted in the axial direction by the gas refrigerant at intermediate pressure
20 that is introduced into the intermediate pressure space 32b.
[0037]
An intermediate pressure Pm1 in the boss portion outer space 38 is the sum of
a pressure Ps in the suction-side space 8 and a predetermined pressure α that is
determined by the elastic force of the intermediate pressure regulating spring 39c and
25 the area of the intermediate pressure regulating valve 39a exposed to intermediate
pressure. That is, the intermediate pressure Pm1 in the boss portion outer space 38
is Ps + α. An intermediate pressure Pm2 in the intermediate pressure space 32b is
the product of the pressure Ps of the suction-side space 8 and a predetermined
magnification β that is determined by the position of the compression chamber 2b
16
communicating with the intermediate pressure space 32b. That is, the intermediate
pressure Pm2 in the intermediate pressure space 32b is Ps × β.
[0038]
The compliant frame 31 is lifted in the axial direction along the inner peripheral
5 surface of the guide frame 30 by the intermediate pressure Pm1, the intermediate
pressure Pm2, and the high pressure caused by the high-pressure gas atmosphere 6
and acting on the compliant frame lower end surface 34. The force caused by such
lifting is referred to as "pushing force".
[0039]
10 By the pushing force of the compliant frame 31, the orbiting scroll 3 is pushed
up via the thrust surface 33, thus being lifted. The lifting of the orbiting scroll 3
reduces gaps formed between the distal ends of the spiral bodies and the base plates
of the fixed scroll 4 and the orbiting scroll 3, forming the compression chamber 2b.
As a result, gas refrigerant at high pressure is less likely to leak from the compression
15 chamber 2b and hence, it is possible to obtain a scroll compressor with high efficiency.
[0040]
In contrast, in the case in which the pressure in the inside of the compression
chamber 2b becomes excessively high at the time of starting up the scroll compressor
100 and at the time of compressing refrigerant, a gas load in the axial direction acting
20 on the orbiting scroll 3 becomes excessively large. In such a case, the orbiting scroll
3 pushes down the compliant frame 31 via the thrust surface 33. That is, relatively
large gaps are formed between the distal ends of the spiral bodies and the base
plates of the fixed scroll 4 and the orbiting scroll 3. Therefore, an abnormal pressure
rise in the compression chamber 2b can be suppressed and hence, it is possible to
25 obtain the scroll compressor 100 with high reliability in which the sliding portions are
not damaged.
[0041]
(When injection is ON)
The action of the scroll compressor 100 when injection is ON will be described.
30 After the scroll compressor 100 is started up, when an opening and closing valve (not
17
shown in the drawing) provided in the injection pipe 50 is opened, injection refrigerant
is supplied to the compression mechanism unit 2 through the injection pipe 50 from
the outside. Specifically, injection refrigerant that passes through the injection pipe
50 is supplied to the compression chamber 2b of the compression mechanism unit 2
5 through the injection inflow passage 4d and the injection port 4e formed in the fixed
scroll 4. The injection refrigerant supplied to the compression chamber 2b is mixed
with refrigerant in the course of compression, which is taken into the compression
chamber 2b from the suction pipe 7, is compressed in the compression chamber 2b
and, thereafter, is discharged from the discharge port 12.
10 [0042]
Next, the flow of oil in the scroll compressor 100 will be described with
reference to Fig. 1. When the drive shaft 19 rotates with the rotation of the electric
motor rotor 16a, the inside of the sealed container 1 is filled with gas that is
compressed by the compression mechanism unit 2, thus becoming the high-pressure
15 gas atmosphere 6. The oil reservoir space 5 that is exposed to the high-pressure
gas atmosphere 6 communicates with the suction-side space 8 of the compression
mechanism unit 2 through the oil supply passage 23 of the drive shaft 19 and hence,
oil in the oil reservoir space 5 is suctioned by a differential pressure. This oil is
supplied to the main bearing 25, the sub-bearing 27, and the orbiting bearing 26
20 through the oil supply passage 23, the supply passage 24a, and the supply passage
24b. The oil supplied to the main bearing 25, the sub-bearing 27, and the orbiting
bearing 26 lubricates the bearings and, thereafter, is returned to the oil reservoir
space 5 disposed at the lower portion of the sealed container 1.
[0043]
25 The oil supplied to the main bearing 25 lubricates the main bearing 25 and,
thereafter, is introduced into the boss portion outer space 38 or the high-pressure gas
atmosphere 6. After oil passes through the main bearing 25, the oil is supplied to
the boss portion 3c of the orbiting scroll 3, and lubricates the orbiting bearing 26.
The oil, in the course of lubricating the orbiting bearing 26, reduces in pressure to an
30 intermediate pressure and, as a result, is introduced into the boss portion outer space
18
38. The oil introduced into the boss portion outer space 38 overcomes the spring
force of the intermediate pressure regulating spring 39c in passing through the
through passage 39e, thus pushing up the intermediate pressure regulating valve 39a,
so that the oil is for an instant discharged to the compliant frame upper space 32a.
5 Thereafter, this oil is discharged to the space located on the inner side of the Oldham
ring 40, and is then supplied to the suction-side space 8.
[0044]
A portion of oil discharged to the compliant frame upper space 32a is supplied
to the thrust surface 3d and, thereafter, is supplied to the reciprocal sliding surface 41,
10 and then flows into the suction-side space 8. The oil that flows into the suction-side
space 8 is suctioned into the compression mechanism unit 2 together with gas
refrigerant at low pressure. The suctioned oil seals and lubricates a gap formed
between the fixed scroll 4 and the orbiting scroll 3, forming the compression
mechanism unit 2, thus allowing a normal operation.
15 [0045]
In the flow of oil when injection is ON, the oil is only mixed with injection
refrigerant in the compression mechanism unit 2 in the above-mentioned path, and
there is no particular change to the flow.
[0046]
20 Fig. 4 is a schematic cross-sectional view of the compression mechanism unit
of the scroll compressor according to Embodiment 1. Fig. 4 shows the cross section
of the compression mechanism unit 2 as viewed from the direction of the orbiting
base plate 3b. For the sake of convenience of description, the bleed inlet 3ei and
the bleed outlet 3eo of the bleed hole 3e and the gas introduction passage 14 are
25 shown in Fig. 4, the bleed hole 3e being provided in the orbiting base plate 3b, the
gas introduction passage 14 being provided in the compliant frame 31. To allow the
fixed spiral body 4a and the orbiting spiral body 3a to be easily distinguished from
each other, the orbiting spiral body 3a is hatched. The same applies in the following
drawings.
30 [0047]
19
The compression mechanism unit 2 has what is called an asymmetric spiral
structure in which the spiral length of the fixed spiral body 4a differs from the spiral
length of the orbiting spiral body 3a. The fixed spiral body 4a is formed to have a
spiral length larger than the spiral length of the orbiting spiral body 3a by an amount
5 corresponding to 180 degrees about the center of the fixed spiral body 4a. In a state
in which both the spiral body of the fixed scroll 4 and the spiral body of the orbiting
scroll 3 are combined, as shown in Fig. 4, the position of an end portion 3f of the
orbiting spiral body 3a is aligned with the position of an end portion 4f of the fixed
spiral body 4a.
10 [0048]
The compression chamber 2b that is formed by combining the fixed spiral body
4a and the orbiting spiral body 3a has a first compression chamber 56a and a second
compression chamber 56b, the first compression chamber 56a, the first compression
chamber 56a being a chamber on the orbiting outwardly facing surface side of the
15 orbiting spiral body 3a, the second compression chamber 56b being a chamber on
the orbiting inwardly facing surface side of the orbiting spiral body 3a. The chamber
on the orbiting outwardly facing surface side is the chamber formed by an outwardly
facing surface 3ab of the orbiting spiral body 3a of the orbiting scroll 3 and an
inwardly facing surface 4aa of the fixed spiral body 4a. The chamber on the orbiting
20 inwardly facing surface side is the chamber formed by an inwardly facing surface 3aa
of the orbiting spiral body 3a and an outwardly facing surface 4ab of the fixed spiral
body 4a.
[0049]
As described above, the injection port 4e is formed in the fixed base plate 4b.
25 At least one injection port 4e is provided in the fixed base plate 4b. Two or more
injection ports 4e may be provided. In Embodiment 1, as shown in Fig. 4, four
injection ports 4e are provided in a line along the circumferential direction. Each
injection port 4e has a circular cross-sectional shape, for example. The diameter of
the injection port 4e is smaller than a wrap thickness t of the orbiting spiral body 3a of
30 the orbiting scroll 3. In other words, the diameter of the injection port 4e and the
20
wrap thickness t of the orbiting spiral body 3a has a size relationship in which the
injection port 4e is completely closed by the orbiting spiral body 3a.
[0050]
The bleed hole 3e communicates with the second compression chamber 56b of
5 the compression chamber 2b. The bleed inlet 3ei of the bleed hole 3e is open to the
second compression chamber 56b. The bleed hole 3e intermittently makes the
second compression chamber 56b at intermediate pressure in the course of
compression communicate with the gas introduction passage 14 of the compliant
frame 31. The bleed hole 3e intermittently makes the second compression chamber
10 56b at intermediate pressure in the course of compression communicate with the
intermediate pressure space 32b through the gas introduction passage 14. Here,
the range of the revolution angle of the orbiting scroll 3 at which the second
compression chamber 56b at intermediate pressure in the course of compression
communicates with the intermediate pressure space 32b through the bleed hole 3e is
15 defined as the intermediate pressure bleed zone. The revolution angle is the angle
about the axis of the main shaft 20 of the drive shaft 19.
[0051]
Next, the positions of the injection ports 4e will be described. The injection
ports 4e are formed within the range from positions inward of the inwardly facing
20 surface 4aa of the fixed spiral body 4a by an amount corresponding to the wrap
thickness t of the orbiting spiral body 3a to positions outward of the outwardly facing
surface 4ab of the fixed spiral body 4a by the amount corresponding to the wrap
thickness t of the orbiting spiral body 3a. By forming the injection ports 4e at the
above-mentioned positions, it is possible to obtain an action in which the injection
25 ports 4e communicate with the first compression chamber 56a within the range of the
revolution angle of the orbiting scroll 3 different from the range of the revolution angle
of the orbiting scroll 3 at which the injection ports 4e communicate with the second
compression chamber 56b. Such a point will be described later.
[0052]
21
The injection ports 4e are formed at positions at which the injection ports 4e
communicate with the second compression chamber 56b when suction of refrigerant
is completed and a compression process is about to be started. With such a
configuration, injection refrigerant is supplied to the second compression chamber
5 56b prior to the first compression chamber 56a. The reason the injection ports 4e
are formed at the above-mentioned positions is as follows.
[0053]
As described above, the compression mechanism unit 2 has an asymmetric
spiral structure. In the case in which the compression mechanism unit 2 has the
10 asymmetric spiral structure, in the second compression chamber 56b on the orbiting
inwardly facing surface side, compression is started with a delay of 180 degrees of
the revolution angle of the orbiting scroll 3 from the compression in the first
compression chamber 56a on the orbiting outwardly facing surface side. Therefore,
the pressure rise in the second compression chamber 56b is delayed compared with
15 the pressure rise in the first compression chamber 56a, so that, at the same
revolution angle, the pressure in the second compression chamber 56b is lower than
the pressure in the first compression chamber 56a. For this reason, a pressure
difference between the pressure of injection refrigerant and the pressure in the
second compression chamber 56b is larger than a pressure difference between the
20 pressure of injection refrigerant and the pressure in the first compression chamber
56a, so that injection refrigerant is more easily supplied to the second compression
chamber 56b than to the first compression chamber 56a. Accordingly, when suction
of refrigerant is completed and the compression process is started, injection of
injection refrigerant is first performed into the second compression chamber 56b into
25 which injection refrigerant can be easily supplied and, thereafter, injection is
performed into the first compression chamber 56a. With such a configuration, it is
possible to increase the amount of injection compared with the conventional
configuration in which injection refrigerant is supplied only to the first compression
chamber 56a.
30 [0054]
22
Further, the injection ports 4e are formed at positions at which the injection
ports 4e are prevented from communicating with the second compression chamber
56b during a period in which the second compression chamber 56b is in
communication with the gas introduction passage 14 through the bleed hole 3e.
5 That is, the injection ports 4e are formed at positions at which the injection ports 4e
are prevented from communicating with the second compression chamber 56b during
a period in which the revolution angle of the orbiting scroll 3 is within the intermediate
pressure bleed zone. For this reason, when the inflow of refrigerant into the second
compression chamber 56b and the outflow of refrigerant from the second
10 compression chamber 56b are considered, there is no possibility that the inflow of
injection refrigerant into the second compression chamber 56b through the injection
ports 4e is performed simultaneously with the outflow of refrigerant from the second
compression chamber 56b through the bleed hole 3e. Hereinafter, the inflow of
injection refrigerant into the second compression chamber 56b through the injection
15 ports 4e is referred to as "injection of refrigerant", and the outflow of refrigerant from
the second compression chamber 56b through the bleed hole 3e is referred to as
"bleeding from the bleed hole 3e".
[0055]

20 Hereinafter, the compression action of the compression mechanism unit 2 will
be described in detail.
[0056]
Fig. 5 is a diagram of a compression process showing actions of the orbiting
scroll of the scroll compressor according to Embodiment 1 during rotation. Fig. 5
25 shows the actions of the orbiting scroll 3 from moment to moment in four stages in
order from (a) to (d). Fig. 6 is a diagram illustrating details of the actions (injection of
refrigerant and bleeding from the bleed hole) in the respective compression chambers
according to the revolution angle in the compression process of the scroll compressor
according to Embodiment 1.
30 [0057]
23
Fig. 5(a) shows a state in which the end portion 3f of the orbiting spiral body 3a
and the end portion 4f of the fixed spiral body 4a are at the same phase. The
revolution angle of the orbiting scroll 3 in this state is assumed as 0°. This is a state
in which, in the first compression chamber 56a and the second compression chamber
5 56b, suction of refrigerant is completed and the compression process is about to be
started. In this state, the second compression chamber 56b communicates with the
injection ports 4e, and injection of refrigerant from the injection ports 4e into the
second compression chamber 56b is performed ((1) in Fig. 6).
[0058]
10 With the revolving motion of the orbiting scroll 3 from the position shown in Fig.
5(a), the injection ports 4e start to be gradually closed by the orbiting spiral body 3a,
so that communication between the second compression chamber 56b and the
injection ports 4e comes to an end.
[0059]
15 Fig. 5(b) shows a state in which communication between the second
compression chamber 56b and the injection ports 4e is ended, and the first
compression chamber 56a communicates with the injection ports 4e. In this state,
injection of refrigerant from the injection ports 4e into the first compression chamber
56a is performed ((2) in Fig. 6). In the case in which a plurality of injection ports 4e
20 are formed as shown in Fig. 5, there is no possibility that some of the plurality of
injection ports 4e communicate with the first compression chamber 56a and some of
the remaining injection ports 4e communicate with the second compression chamber
56b. That is, there is no possibility of the plurality of injection ports 4e
communicating with the first compression chamber 56a and the second compression
25 chamber 56b simultaneously.
[0060]
Fig. 5(c) shows a state in which the bleed outlet 3eo of the bleed hole 3e
formed in the orbiting base plate 3b starts to communicate with the gas introduction
passage 14. That is, Fig. 5(c) shows a state at the beginning of the intermediate
30 pressure bleed zone. The revolution angle of the orbiting scroll 3 with the orbiting
24
scroll 3 located at the position shown in Fig. 5(c) is assumed as a first revolution
angle. That is, the first revolution angle is the revolution angle of the orbiting scroll 3
at which the intermediate pressure bleed zone starts. When the orbiting scroll 3 is
located at the first revolution angle, the bleed hole 3e communicates with the gas
5 introduction passage 14, and bleeding from the bleed hole 3e is performed ((3) in Fig.
6). Further, when the orbiting scroll 3 is located at the first revolution angle, the
injection ports 4e communicate with the first compression chamber 56a continuously
from the state shown in Fig. 5(b), and injection of refrigerant into the first compression
chamber 56a is performed ((2) in Fig. 6).
10 [0061]
Fig. 5(d) shows a state immediately after communication between the bleed
outlet 3eo of the bleed hole 3e formed in the orbiting base plate 3b and the gas
introduction passage 14 is completed. The revolution angle of the orbiting scroll 3
with the orbiting scroll 3 located at the position shown in Fig. 5(d) is assumed as a
15 second revolution angle. That is, the second revolution angle is the revolution angle
of the orbiting scroll 3 at which the intermediate pressure bleed zone ends. When
the orbiting scroll 3 is located at the second revolution angle, the bleed hole 3e faces
the thrust surface 33 of the compliant frame 31, so that the bleed hole 3e is closed by
the thrust surface 33. Therefore, bleeding from the bleed hole 3e is stopped.
20 [0062]
Further, when the orbiting scroll 3 is located at the second revolution angle, the
injection ports 4e start communication with the second compression chamber 56b,
and injection of refrigerant from the injection ports 4e into the second compression
chamber 56b is performed ((4) in Fig. 6). That is, when the orbiting scroll 3 is
25 located at the second revolution angle, in the second compression chamber 56b,
bleeding from the bleed hole 3e is switched to injection of refrigerant. The timing at
which injection of refrigerant into the second compression chamber 56b is started is
not limited to when the orbiting scroll 3 is located at the second revolution angle, and
it is sufficient that the timing at which injection of refrigerant into the second
30 compression chamber 56b is started fall outside the intermediate pressure bleed zone.
25
[0063]
In contrast, in the case in which the orbiting scroll 3 is located at the second
revolution angle, in the first compression chamber 56a, the injection ports 4e that
communicate with the first compression chamber 56a are closed by the orbiting spiral
5 body 3a, so that injection of refrigerant is ended. After the state shown in Fig. 5(d),
the compression mechanism unit 2 returns to the state shown in Fig. 5(a).
[0064]
When the above-mentioned series of actions are summarized, as can be
clearly understood from Fig. 6, injection of refrigerant into the first compression
10 chamber 56a is performed within the range of the revolution angle of the orbiting
scroll 3 different from the range of the revolution angle of the orbiting scroll 3 at which
injection of refrigerant into the second compression chamber 56b is performed. This
is because the injection ports 4e are formed within the range from the positions
inward of the inwardly facing surface 4aa of the fixed spiral body 4a by an amount
15 corresponding to the wrap thickness of the orbiting spiral body 3a to the positions
outward of the outwardly facing surface 4ab of the fixed spiral body 4a by the amount
corresponding to the wrap thickness of the orbiting spiral body 3a. The injection
ports 4e are formed within the above-mentioned range, so that the orbiting spiral body
3a slides and moves over the injection ports 4e in the radial direction during the
20 revolving motion of the orbiting scroll 3. Therefore, it is possible to obtain an action
in which the injection ports 4e communicate with the first compression chamber 56a
or the second compression chamber 56b and hence, injection of refrigerant can be
performed into both the first compression chamber 56a and the second compression
chamber 56b.
25 [0065]
Further, the injection ports 4e are formed at positions at which the injection
ports 4e communicate with the second compression chamber 56b when suction of
refrigerant is completed. Therefore, as shown in Fig. 6, after the compression
process is started, injection of refrigerant into the second compression chamber 56b
30 ((1) in Fig. 6) is performed prior to injection of refrigerant into the first compression
26
chamber 56a ((2) in Fig. 6). The pressure in the second compression chamber 56b
is lower than the pressure in the first compression chamber 56a and hence, it is
possible to increase the amount of injection.
[0066]
5 As described above, the pressure in the first compression chamber 56a differs
from the pressure in the second compression chamber 56b, that is, there is a
pressure difference between the first compression chamber 56a and the second
compression chamber 56b. Therefore, the size and the shape of the injection ports
4e are designed such that the first compression chamber 56a and the second
10 compression chamber 56b are prevented from communicating with each other
through the injection ports 4e. With such a configuration, it is possible to prevent
refrigerant in the second compression chamber 56b from leaking to the first
compression chamber 56a.
[0067]
15 In Embodiment 1, the configuration is adopted in which although injection of
refrigerant into both the first compression chamber 56a and the second compression
chamber 56b is allowed, injection of refrigerant into the second compression chamber
56b is not performed simultaneously with bleeding from the second compression
chamber 56b. If injection of refrigerant into the second compression chamber 56b is
20 performed simultaneously with bleeding from the second compression chamber 56b,
an excess amount of refrigerant gas is supplied to the intermediate pressure space
32b via the bleed hole 3e and the gas introduction passage 14.
[0068]
When an excess amount of refrigerant gas is supplied to the intermediate
25 pressure space 32b, the pressure in the intermediate pressure space 32b increases,
so that an excessively large pushing force acts on the orbiting scroll 3 from the
compliant frame 31. However, in Embodiment 1, the injection ports 4e do not
communicate with the second compression chamber 56b within the intermediate
pressure bleed zone, so that there is no possibility that injection of refrigerant into the
30 second compression chamber 56b is performed simultaneously with bleeding from
27
the second compression chamber 56b. Therefore, it is possible to prevent an
excessively large pushing force from acting on the orbiting scroll 3 from the compliant
frame 31. For this reason, it is possible to perform injection of refrigerant for both the
first compression chamber 56a and the second compression chamber 56b while
5 taking advantage of characteristics of the compliant frame 31 and hence, an increase
in refrigeration capacity can be expected.
[0069]

Next, a refrigeration cycle apparatus in which the scroll compressor 100 is
10 mounted will be described.
Fig. 7 is a schematic configuration diagram of the refrigeration cycle apparatus
according to Embodiment 1.
The refrigeration cycle apparatus 200 includes the scroll compressor 100, a
four-way selector valve 103, and an outdoor-side heat exchanger 104, the four-way
15 selector valve 103 being connected to the discharge side of the scroll compressor
100. The refrigeration cycle apparatus 200 also includes a pressure reducer 105a
and a pressure reducer 105b, being electric expansion valves, for example, an
indoor-side heat exchanger 106, and a gas-liquid separator 107. In the refrigeration
cycle apparatus 200, these devices are connected in sequence via pipes, thus
20 forming a refrigeration circuit. Each of the outdoor-side heat exchanger 104 and the
indoor-side heat exchanger 106 serves as a condenser or an evaporator according to
the switching of the four-way selector valve 103. In the refrigeration cycle apparatus
200, the four-way selector valve 103 may be omitted. For this reason, the
refrigeration cycle apparatus 200 may be configured to include the scroll compressor
25 100, a condenser, pressure reducers, an evaporator, and the gas-liquid separator 107.
[0070]
The gas-liquid separator 107 separates two-phase refrigerant that flows into
the gas-liquid separator 107 into saturated gas refrigerant and saturated liquid
refrigerant. The gas-liquid separator 107 includes the injection pipe 50 being a gas
30 outflow pipe that allows separated saturated gas refrigerant to flow out to the outside.
28
The downstream end of the injection pipe 50 is connected to the scroll compressor
100. An opening and closing valve 50a is connected to the injection pipe 50, the
opening and closing valve 50a opening and closing the injection pipe 50.
[0071]
5 In a heating operation in a case in which the refrigeration cycle apparatus 200
is applied to an air-conditioning apparatus, for example, the four-way selector valve
103 is connected as shown by solid lines in Fig. 5. Refrigerant at high temperature
and high pressure compressed by the scroll compressor 100 flows into the indoorside heat exchanger 106, and is condensed and liquefied and, thereafter, is reduced
10 in pressure by the pressure reducer 105b, thus becoming a two-phase state at low
temperature and low pressure. Thereafter, the refrigerant in the two-phase state
flows into the gas-liquid separator 107. Saturated liquid refrigerant separated by the
gas-liquid separator 107 passes through the pressure reducer 105a, flows into the
outdoor-side heat exchanger 104, is evaporated, and is gasified. The gasified
15 refrigerant passes through the four-way selector valve 103, and then returns to the
scroll compressor 100 again. That is, in the heating operation, refrigerant cycles as
shown by solid line arrows in Fig. 5. Due to such cycling, in the outdoor-side heat
exchanger 104 serving as an evaporator, refrigerant exchanges heat with outside air
to receive heat. The refrigerant that receives heat is sent to the indoor-side heat
20 exchanger 106, serving as a condenser, and exchanges heat with indoor air to heat
the indoor air.
[0072]
In a cooling operation in a case in which the refrigeration cycle apparatus 200
is applied to an air-conditioning apparatus, for example, the four-way selector valve
25 103 is connected as shown by broken lines in Fig. 5. Refrigerant at high
temperature and high pressure compressed in the scroll compressor 100 flows into
the outdoor-side heat exchanger 104, is condensed and liquefied and, thereafter, is
reduced in pressure by the pressure reducer 105a, thus becoming a two-phase state
at low temperature and low pressure. Then, the refrigerant flows into the gas-liquid
30 separator 107. Saturated liquid refrigerant separated by the gas-liquid separator 107
29
flows into the indoor-side heat exchanger 106 via the pressure reducer 105b, is
evaporated, and is gasified. The gasified refrigerant passes through the four-way
selector valve 103, and then returns to the scroll compressor 100 again. That is, in
the cooling operation, refrigerant cycles as shown by broken line arrows in Fig. 5.
5 Due to such cycling, in the indoor-side heat exchanger 106 serving as an evaporator,
refrigerant exchanges heat with indoor air to receive heat from the indoor air. Thus
the indoor air is cooled. The refrigerant that receives heat is sent to the outdoor-side
heat exchanger 104 serving as a condenser, and exchanges heat with outside air to
transfer heat to the outside air.
10 [0073]
In the above-mentioned heating operation and cooling operation, saturated gas
refrigerant separated by the gas-liquid separator 107 is supplied to the scroll
compressor 100 through the injection pipe 50. The saturated gas refrigerant
supplied to the scroll compressor 100 is supplied to the first compression chamber
15 56a or the second compression chamber 56b through the injection inflow passage 4d
and the injection ports 4e provided in the fixed base plate 4b of the fixed scroll 4. In
the refrigeration cycle apparatus 200 including the gas-liquid separator 107, injection
refrigerant is gas refrigerant, so that gas injection is performed.
[0074]
20 In Embodiment 1, the description has been made for the refrigeration cycle
apparatus 200 including the gas-liquid separator 107. However, a refrigeration cycle
apparatus to which the scroll compressor 100 of the present disclosure is applied is
not limited to a refrigeration cycle apparatus including the gas-liquid separator 107.
A refrigeration cycle apparatus to which the scroll compressor 100 of the present
25 disclosure is applied may be a refrigeration cycle apparatus that includes a scroll
compressor, a condenser, pressure reducers, and an evaporator without including the
gas-liquid separator 107, for example. In this case, it is sufficient to adopt a
configuration in which refrigerant between the condenser and the pressure reducer is
branched, and the branched refrigerant is reduced in pressure and is injected into the
30 scroll compressor 100.
30
[0075]
As described above, the scroll compressor 100 of Embodiment 1 includes the
compression mechanism unit 2 including the fixed scroll 4 and the orbiting scroll 3.
The compression mechanism unit 2 causes the orbiting scroll 3 to perform a revolving
5 motion relative to the fixed scroll 4 to compress refrigerant in the compression
chamber 2b formed by combining the fixed spiral body 4a of the fixed scroll 4 and the
orbiting spiral body 3a of the orbiting scroll 3. The compression mechanism unit 2
has an asymmetric spiral structure in which the spiral length of the fixed spiral body
4a of the fixed scroll 4 differs from the spiral length of the orbiting spiral body 3a of the
10 orbiting scroll 3. The injection ports 4e are formed in the fixed base plate 4b,
injection refrigerant being supplied to the compression chamber 2b through the
injection ports 4e. The compression chamber 2b has the first compression chamber
56a and the second compression chamber 56b, the first compression chamber 56a
being formed by the outwardly facing surface 3ab of the orbiting spiral body 3a and
15 the inwardly facing surface 4aa of the fixed spiral body 4a, the second compression
chamber 56b being formed by the inwardly facing surface 3aa of the orbiting spiral
body 3a and the outwardly facing surface 4ab of the fixed spiral body 4a. The
injection ports 4e are formed within the range from the positions inward of the
inwardly facing surface 4aa of the fixed spiral body 4a by an amount corresponding to
20 the wrap thickness of the orbiting spiral body 3a to the positions outward of the
outwardly facing surface 4ab of the fixed spiral body 4a by the amount corresponding
to the wrap thickness of the orbiting spiral body 3a. Further, the injection ports 4e
are formed at positions at which the injection ports 4e communicate with the second
compression chamber 56b when suction of refrigerant is completed.
25 [0076]
As described above, the injection ports 4e are formed within the range from the
positions inward of the inwardly facing surface 4aa of the fixed spiral body 4a by the
amount corresponding to the wrap thickness of the orbiting spiral body 3a to the
positions outward of the outwardly facing surface 4ab of the fixed spiral body 4a by
30 the amount corresponding to the wrap thickness of the orbiting spiral body 3a. With
31
such a configuration, it is possible to perform injection into both the first compression
chamber 56a and the second compression chamber 56b. Further, the injection ports
4e are formed at positions at which the injection ports 4e communicate with the
second compression chamber 56b when suction of refrigerant is completed and the
5 compression process is about to be started. With such a configuration, in performing
injection into both the first compression chamber 56a and the second compression
chamber 56b, injection into the second compression chamber 56b is performed prior
to injection into the first compression chamber 56a in the asymmetric spiral structure,
the pressure in the second compression chamber 56b being lower than the pressure
10 in the first compression chamber 56a. As a result of the above, it is possible to
obtain a high injection flow rate.
[0077]
In the scroll compressor 100 of Embodiment 1, the orbiting base plate 3b has
the bleed hole 3e being a hole formed in such a way as to penetrate through the
15 orbiting base plate 3b from one surface of the orbiting base plate 3b, on which the
orbiting spiral body 3a is provided, to the other surface of the orbiting base plate 3b.
The bleed hole 3e intermittently make the second compression chamber 56b at
intermediate pressure communicate with the intermediate pressure space 32b, the
intermediate pressure being higher than the suction pressure of the refrigerant and
20 lower than the discharge pressure of the refrigerant, the intermediate pressure space
32b being formed between the compliant frame 31 and the guide frame 30 at a
position near the other surface of the orbiting base plate 3b. A range of the
revolution angle of the orbiting scroll 3 at which the second compression chamber
56b communicates with the intermediate pressure space 32b through the bleed hole
25 3e is defined as the intermediate pressure bleed zone. In this case, the injection
ports 4e are formed at positions at which the injection ports 4e are prevented from
communicating with the second compression chamber 56b during a period in which
the revolution angle of the orbiting scroll 3 is within the intermediate pressure bleed
zone. The scroll compressor 100 includes the compliant frame 31 and the guide
30 frame 30. The intermediate pressure space 32b is a space formed between the
32
compliant frame 31 and the guide frame 30. The compliant frame 31 supports the
orbiting scroll 3 in the axial direction due to the intermediate pressure caused by
refrigerant introduced into the intermediate pressure space 32b from the second
compression chamber 56b through the bleed hole 3e.
5 [0078]
As described above, the injection ports 4e are formed at positions at which the
injection ports 4e are prevented from communicating with the second compression
chamber 56b during a period in which the revolution angle of the orbiting scroll 3 is
within the intermediate pressure bleed zone. With such a configuration, it is possible
10 to prevent injection of refrigerant into the second compression chamber 56b from
being performed simultaneously with bleeding from the second compression chamber
56b and hence, it is possible to prevent an excess amount of refrigerant gas from
being supplied to the intermediate pressure space 32b from the second compression
chamber 56b. As it is possible to prevent an excess amount of refrigerant gas from
15 being supplied to the intermediate pressure space 32b, it is possible to prevent a
situation in which the pressure in the intermediate pressure space 32b increases, so
that an excessively large pushing force acts on the orbiting scroll 3 from the compliant
frame 31.
[0079]
20 In the scroll compressor 100 of Embodiment 1, the gas introduction passage 14
is formed in the compliant frame 31, the gas introduction passage 14 communicating
with the bleed hole 3e when the revolution angle of the orbiting scroll 3 is within the
intermediate pressure bleed zone, the gas introduction passage 14 introducing
refrigerant at intermediate pressure in the second compression chamber 56b into the
25 intermediate pressure space 32b. Further, the thrust surface 33 is formed on the
compliant frame 31, the thrust surface 33 forming a facing surface that faces the
bleed hole 3e and closes the bleed hole 3e when the revolution angle of the orbiting
scroll 3 falls outside the intermediate pressure bleed zone.
[0080]
33
As described above, due to the gas introduction passage 14 formed in the
compliant frame 31 and the thrust surface 33 formed on the compliant frame 31, the
second compression chamber 56b is intermittently made communicate with the
intermediate pressure space 32b.
5 [0081]
The scroll compressor 100 of Embodiment 1 has two or more injection ports 4e.
[0082]
By providing two or more injection ports 4e as described above, it is possible to
further increase the amount of injection.
10 Reference Signs List
[0083]
1: sealed container, 2: compression mechanism unit, 2b: compression chamber,
3: orbiting scroll, 3a: orbiting spiral body, 3aa: inwardly facing surface, 3ab: outwardly
facing surface, 3b: orbiting base plate, 3c: boss portion, 3d: thrust surface, 3e: bleed
15 hole, 3ei: bleed inlet, 3eo: bleed outlet, 3f: end portion, 4: fixed scroll, 4a: fixed spiral
body, 4 aa: inwardly facing surface, 4 ab: outwardly facing surface, 4b: fixed base
plate, 4d: injection inflow passage, 4e: injection port, 4f: end portion, 5: oil reservoir
space, 6: high-pressure gas atmosphere, 7: suction pipe, 8: suction-side space, 9:
suction check valve, 10: spring, 11: discharge pipe, 12: discharge port, 14: gas
20 introduction passage, 15a: fixed-side Oldham ring groove, 15b: orbiting-side Oldham
ring groove, 16: electric motor, 16a: electric motor rotor, 16b: electric motor stator,
18a: balance weight, 18b: balance weight, 19: drive shaft, 20: main shaft, 21: orbiting
shaft, 22: sub-shaft, 23: oil supply passage, 24a: supply passage, 24b: supply
passage, 25: main bearing, 26: orbiting bearing, 27: sub-bearing, 28: thrust bearing,
25 29: holder, 30: guide frame, 30a: upper fitting cylindrical surface, 30b: lower fitting
cylindrical surface, 30c: flow passage, 31: compliant frame, 32a: compliant frame
upper space, 32b: intermediate pressure space, 33: thrust surface, 34: compliant
frame lower end surface, 35a: upper fitting cylindrical surface, 35b: lower fitting
cylindrical surface, 36a: upper annular sealing part, 36b: lower annular sealing part,
30 37: sub-frame, 38: boss portion outer space, 39a: intermediate pressure regulating
34
valve, 39c: intermediate pressure regulating spring, 39d: intermediate pressure
regulating valve space, 39e: through passage, 40: Oldham ring, 41: reciprocal sliding
surface, 42a: fixed-side key, 42b: orbiting-side key, 50: injection pipe, 50a: opening
and closing valve, 56a: first compression chamber, 56b: second compression
5 chamber, 100: scroll compressor, 103: four-way selector valve, 104: outdoor-side heat
exchanger, 105a: pressure reducer, 105b: pressure reducer, 106: indoor-side heat
exchanger, 107: gas-liquid separator, 200: refrigeration cycle apparatus

35
We Claim :
[Claim 1]
A scroll compressor comprising a compression mechanism unit including a
fixed scroll and an orbiting scroll, the fixed scroll including a fixed base plate and a
5 fixed spiral body provided on the fixed base plate, the orbiting scroll including an
orbiting base plate and an orbiting spiral body provided on the orbiting base plate, the
compression mechanism unit being configured to cause the orbiting scroll to perform
a revolving motion relative to the fixed scroll to compress refrigerant in a compression
chamber formed by combining the fixed spiral body and the orbiting spiral body,
10 wherein
the compression mechanism unit has an asymmetric spiral structure in which a
spiral length of the fixed spiral body of the fixed scroll differs from a spiral length of the
orbiting spiral body of the orbiting scroll, and an injection port is formed in the fixed
base plate, injection refrigerant being supplied to the compression chamber through
15 the injection port,
the compression chamber has a first compression chamber and a second
compression chamber, the first compression chamber being formed by an outwardly
facing surface of the orbiting spiral body and an inwardly facing surface of the fixed
spiral body, the second compression chamber being formed by an inwardly facing
20 surface of the orbiting spiral body and an outwardly facing surface of the fixed spiral
body, and
to allow the injection port to communicate with the first compression chamber
within a range of a revolution angle of the orbiting scroll different from a range of a
revolution angle of the orbiting scroll at which the injection port communicates with
25 the second compression chamber, the injection port is formed within a range from a
position inward of the inwardly facing surface of the fixed spiral body by an amount
corresponding to a wrap thickness of the orbiting spiral body to a position outward of
the outwardly facing surface of the fixed spiral body by the amount corresponding to
the wrap thickness of the orbiting spiral body, the injection port being formed at a
30 position at which the injection port communicates with the second compression
36
chamber when suction of refrigerant is completed and a compression process is
about to be started.
[Claim 2]
The scroll compressor of claim 1, wherein
5 the orbiting base plate has a bleed hole being a hole formed in such a way as
to penetrate through the orbiting base plate from one surface of the orbiting base
plate, on which the orbiting spiral body is provided, to an other surface of the orbiting
base plate, the bleed hole intermittently making the second compression chamber at
intermediate pressure communicate with an intermediate pressure space, the
10 intermediate pressure being higher than a suction pressure of the refrigerant and
lower than a discharge pressure of the refrigerant, the intermediate pressure space
being formed at a position near the other surface of the orbiting base plate, and
when a range of the revolution angle of the orbiting scroll at which the second
compression chamber communicates with the intermediate pressure space through
15 the bleed hole is defined as an intermediate pressure bleed zone,
the injection port is formed at a position at which the injection port is prevented
from communicating with the second compression chamber during a period in which
the revolution angle of the orbiting scroll is within the intermediate pressure bleed
zone.
20 [Claim 3]
The scroll compressor of claim 2 comprising:
a compliant frame being in contact with the other surface of the orbiting scroll to
support the orbiting scroll in an axial direction; and
a guide frame disposed on the compliant frame on a side opposite to the
25 orbiting scroll, the guide frame being configured to house the compliant frame,
wherein
the intermediate pressure space is a space formed between the compliant
frame and the guide frame, and
the compliant frame is configured to support the orbiting scroll in the axial
30 direction due to an intermediate pressure caused by refrigerant introduced into the
37
intermediate pressure space from the second compression chamber through the
bleed hole.
[Claim 4]
The scroll compressor of claim 3, wherein
5 an introduction passage is formed in the compliant frame and a facing surface
is formed on the compliant frame, the introduction passage communicating with the
bleed hole to introduce refrigerant at intermediate pressure in the second
compression chamber into the intermediate pressure space when the revolution angle
of the orbiting scroll is within the intermediate pressure bleed zone, the facing surface
10 facing and closing the bleed hole when the revolution angle of the orbiting scroll falls
outside the intermediate pressure bleed zone.
[Claim 5]
The scroll compressor of any one of claims 1 to 4, wherein the injection port
includes two or more injection ports.
15 [Claim 6]
A refrigeration cycle apparatus comprising: the scroll compressor according to
any one of claims 1 to 5; a condenser, a pressure reducer, and an evaporator.
[Claim 7]
The refrigeration cycle apparatus of claim 6, further comprising a gas-liquid
20 separator, wherein saturated gas refrigerant separated by the gas-liquid separator is
supplied to the compression chamber from the injection port of the scroll compressor.