1
FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
ROTARY COMPRESSOR AND REFRIGERATION CYCLE DEVICE;
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
Technical Field
5 [0001]
The present disclosure relates to a rotary compressor including a partition unit
closing a through hole in a cylinder, and a refrigeration cycle device.
Background Art
[0002]
10 A related-art rotary compressor is provided with an electric motor including a
rotor and a stator at an upper part inside a sealed container. The rotation of the
electric motor is transmitted to the lower side by a crankshaft fixed to the rotor. A
compression mechanism unit is disposed on the lower side of the crankshaft. The
compression mechanism unit generally includes a cylinder, a main bearing, a sub
15 bearing, an intermediate plate, and a piston. In the compression mechanism unit, a
piston moves eccentrically in accordance with the rotation of the eccentric crankshaft.
Thus, when the volume of the compression chamber is reduced, refrigerant is
compressed.
[0003]
20 Further, in one or a plurality of the main bearing, the sub bearing, and the
intermediate plate, an injection hole for introducing injection refrigerant is formed to
communicate with the compression chamber. Intermediate-pressure liquid or gas
refrigerant is injected as injection refrigerant into the compression chamber via an
injection flow path branching off from the middle of a refrigerant circuit. As the
25 injection refrigerant is injected into the compression chamber from the injection flow
path, in addition to suction refrigerant from a main circuit of the refrigerant circuit, the
amount of refrigerant discharged is increased, so that the refrigerant flow rate on the
condenser side of the refrigerant circuit is increased. As a result, the heating
capacity is improved. Further, sliding parts included in the compression mechanism
30 unit are cooled by the injection refrigerant, so that an appropriate clearance is
3
maintained between the sliding parts. This improves the reliability of the rotary
compressor.
[0004]
A known twin rotary compressor having an injection flow path is configured
such that the injection flow path is formed in an intermediate plate 5 (see, for example,
Patent Literatures 1 and 2).
Citation List
Patent Literature
[0005]
10 Patent Literature 1: Japanese Unexamined Patent Application Publication No.
2012-251485
Patent Literature 2: Japanese Unexamined Patent Application Publication No.
2016-23582
Summary of Invention
15 Technical Problem
[0006]
To form an injection flow path in a twin rotary compressor, the injection flow
path needs to be formed in a partition unit such as a bearing or an intermediate plate.
The bearing or the intermediate plate on the inner side of the inner circumference of a
20 cylinder has a section where injection refrigerant does not flow at all because an
eccentrically-moving piston passes therethrough. In the section where injection
refrigerant does not flow, suction refrigerant from a main circuit of a refrigeration cycle
circuit is the only refrigerant that flows into a compression chamber. Therefore, the
amount of refrigerant discharged is reduced, so that the injection effect is reduced.
25 Moreover, in the section where injection refrigerant does not flow, sliding parts are not
cooled. Therefore, the reliability cannot be improved.
[0007]
The present disclosure has been made to solve the above problems, and an
object of the present disclosure is to provide a twin rotary compressor and a
30 refrigeration cycle device in which injection refrigerant always flows into a
4
compression chamber regardless of the eccentric motion of a piston such that the
amount of refrigerant discharged is increased to achieve the injection effect, and such
that sliding parts are always cooled to improve the reliability.
Solution to Problem
5 [0008]
A rotary compressor according to one embodiment of the present disclosure
includes: an electric motor including a stator and a rotor; a crankshaft including an
eccentric portion that is provided on a main shaft fixed to the rotor, and is rotated by
the electric motor; a piston provided on the eccentric portion; a cylinder having a
10 cylindrical through hole in which the eccentric portion and the piston are disposed to
form a compression chamber; an injection flow path through which injection
refrigerant is injected into the compression chamber; and a partition unit closing the
through hole in the cylinder; wherein the injection flow path has a plurality of injection
holes for injecting the injection refrigerant from an inside of the partition unit into the
15 compression chamber, and a common hole formed inside the partition unit and
communicating with the plurality of injection holes.
[0009]
A refrigeration cycle device according to another embodiment of the present
disclosure includes the rotary compressor described above.
20 Advantageous Effects of Invention
[0010]
According to the rotary compressor and the refrigeration cycle device of the
embodiments of the present disclosure, the injection flow path has the plurality of
injection holes for injecting the injection refrigerant from the inside of the partition unit
25 into the compression chamber, and the common hole formed inside the partition unit
and communicating with the plurality of injection holes. Accordingly, the opening
area for the injection refrigerant to be injected into the compression chamber is
increased with a simple configuration. Further, the injection flow path can always
communicate with the compression chamber. Accordingly, the injection refrigerant
30 always flows into the compression chamber, regardless of the eccentric motion of the
5
piston. Thus, the amount of refrigerant discharged is increased, so that the injection
effect is achieved. Also, sliding parts are always cooled, so that the reliability is
increased.
Brief Description of Drawings
5 [0011]
[Fig. 1] Fig. 1 is a refrigerant circuit diagram illustrating a refrigeration cycle
device to which a twin rotary compressor is applied according to Embodiment 1 of the
present disclosure.
[Fig. 2] Fig. 2 is an explanatory view illustrating a longitudinal section of the
10 twin rotary compressor according to Embodiment 1 of the present disclosure.
[Fig. 3] Fig. 3 is a side view illustrating an upper bearing in which a common
hole is formed according to Embodiment 1 of the present disclosure.
[Fig. 4] Fig. 4 is an explanatory view illustrating a transverse section where
injection holes open to a compression chamber are visible according to Embodiment
15 1 of the present disclosure.
[Fig. 5] Fig. 5 is an explanatory view illustrating a transverse section of the
upper bearing in which the common hole and the injection holes are formed in the
cross-section A-A of Fig. 4 according to Embodiment 1 of the present disclosure.
[Fig. 6] Fig. 6 is an explanatory view illustrating a longitudinal section of a
20 piston according to Embodiment 1 of the present disclosure.
[Fig. 7] Fig. 7 is an explanatory view illustrating the open state of the injection
holes in accordance with the eccentric motion of the piston in the range of 0 to 360,
according to Embodiment 1 of the present disclosure.
[Fig. 8] Fig. 8 is an explanatory view illustrating a transverse section where
25 injection holes open to a compression chamber are visible according to Modification 1
of Embodiment 1 of the present disclosure.
[Fig. 9] Fig. 9 is an explanatory view illustrating a longitudinal section of a
compression mechanism unit of a twin rotary compressor according to Embodiment 2
of the present disclosure.
6
[Fig. 10] Fig. 10 is an explanatory view illustrating a transverse section of an
intermediate plate in which a common hole and injection holes are formed according
to Embodiment 2 of the present disclosure.
[Fig. 11] Fig. 11 is an explanatory view illustrating a transverse section of an
intermediate plate in which common holes and injection holes are 5 formed according
to Modification 2 of Embodiment 2 of the present disclosure.
[Fig. 12] Fig. 12 is an explanatory view illustrating a transverse section where
injection holes open to a compression chamber are visible according to Embodiment
3 of the present disclosure.
10 [Fig. 13] Fig. 13 is an explanatory view illustrating a transverse section where
injection holes open to a compression chamber are visible according to Embodiment
4 of the present disclosure.
Description of Embodiments
[0012]
15 Embodiments of the present disclosure will be described with reference to the
drawings. Note that components denoted by the same reference signs in the
drawings correspond to the same or equivalent components. This applies
throughout the specification. Further, in the drawings illustrating cross-sectional
views, some hatching is omitted for clarity. Furthermore, the forms of the
20 components described herein are merely examples, and the components are not
limited thereto.
[0013]
Embodiment 1

25 Fig. 1 is a refrigerant circuit diagram illustrating a refrigeration cycle device 200
to which a twin rotary compressor 100 is applied according to Embodiment 1 of the
present disclosure.
[0014]
As illustrated in Fig. 1, the refrigeration cycle device 200 includes the twin
30 rotary compressor 100, a condenser 201, an expansion valve 202, and an evaporator
7
203. The twin rotary compressor 100, the condenser 201, the expansion valve 202,
and the evaporator 203 are connected with a refrigerant pipe 204 to form a
refrigeration cycle circuit. Refrigerant having flowed out of the evaporator 203 is
suctioned into the twin rotary compressor 100 via an accumulator 206 to become
high-temperature and high-pressure refrigerant. The high-temperature 5 and highpressure
refrigerant is condensed into liquid in the condenser 201. The liquid
refrigerant is reduced in pressure and expanded by the expansion valve 202 to be
low-temperature low-pressure two-phase gas-liquid refrigerant. The lowtemperature
low-pressure two-phase gas-liquid refrigerant exchanges heat in the
10 evaporator 203.
[0015]
The refrigeration cycle device 200 includes an injection flow path 205 through
which refrigerant is injected into the compression chamber from a separator 207
located in the refrigerant pipe 204 just before the evaporator 203, and more
15 specifically, just before the expansion valve 202 in the refrigerant flowing direction in
the refrigeration cycle circuit. A control valve 208 that controls the flow rate of the
injection refrigerant is disposed halfway along the injection flow path 205. The
control valve 208 is located in the injection flow path 205 on the upstream side of the
twin rotary compressor 100 in the injection refrigerant flowing direction. The control
20 valve 208 includes, for example, an opening/closing valve, a check valve, or a flow
control valve, and regulates the injection refrigerant flow rate to achieve the optimum
injection effect. Note that the injection flow path 205 will be described below in
detail.
[0016]
25 The twin rotary compressor 100 described below is applicable to the
refrigeration cycle device 200 described above. Note that examples of the
refrigeration cycle device 200 include an air-conditioning device, a refrigeration
device, and a water heater.
[0017]
30
8
Fig. 2 is an explanatory view illustrating a longitudinal section of the twin rotary
compressor 100 according to Embodiment 1 of the present disclosure. Fig. 3 is a
side view illustrating an upper bearing 109a in which a first common hole 205f1 is
formed according to Embodiment 1 of the present disclosure. Fig. 4 is an
explanatory view illustrating a transverse section where a first injection 5 hole 205a1
and a second injection hole 205a2 open to a first compression chamber 106a are
visible according to Embodiment 1 of the present disclosure. Fig. 5 is an
explanatory view illustrating a transverse section of the upper bearing 109a in which
the first common hole 205f1, the first injection hole 205a1, and the second injection
10 hole 205a2 are formed in the cross-section A-A of Fig. 4 according to Embodiment 1
of the present disclosure. Fig. 6 is an explanatory view illustrating a longitudinal
section of a first piston 105a according to Embodiment 1 of the present disclosure.
[0018]
As illustrated in Fig. 2, the twin rotary compressor 100 includes a cylindrical
15 sealed container 101 with closed upper and lower ends. The sealed container 101
includes a cylindrical unit 101a, an upper end closing unit 101b closing the upper end
of the cylindrical unit 101a, and a lower end closing unit 101c closing the lower end of
the cylindrical unit 101a. The sealed container 101 is installed and fixed to a base
102.
20 [0019]
An electric motor 103 is disposed at an upper part inside the sealed container
101. The electric motor 103 includes a stator 103a and a rotor 103b. The stator
103a of the electric motor 103 has a cylindrical shape, and is fixed to the inner
circumferential wall of the sealed container 101. The rotor 103b has a cylindrical
25 shape, and is disposed in a hollow portion at the center of the stator 103a to be
rotatable in the horizontal direction and the circumferential direction.
[0020]
A crankshaft 104 rotated by the electric motor 103 is disposed so as to extend
vertically in the sealed container 101. The crankshaft 104 includes a main shaft
9
104a, a first eccentric portion 104b, a second eccentric portion 104c, and a sub shaft
104d.
[0021]
The main shaft 104a is fixed to the rotor 103b. The main shaft 104a transmits
the rotational driving force of the rotor 103b to the first eccentric portion 5 104b and the
second eccentric portion 104c. The first eccentric portion 104b is disposed on the
main shaft 104a, on the main shaft 104a side above the second eccentric portion
104c, and has a center axis eccentric to the main shaft 104a. The first eccentric
portion 104b is wider than the main shaft 104a. The second eccentric portion 104c
10 is disposed on the main shaft 104a, on the sub shaft 104d side below the first
eccentric portion 104b, and has a center axis eccentric to the main shaft 104a and the
first eccentric portion 104b. The second eccentric portion 104c is wider than the
main shaft 104a.
[0022]
15 As illustrated in Fig. 4, the first piston 105a is provided on the first eccentric
portion 104b. The first piston 105a includes a vane 105a1 partitioning the first
compression chamber 106a. The first piston 105a is called also as a rolling piston.
[0023]
The first eccentric portion 104b and the first piston 105a are disposed in a first
20 cylinder 107a having a cylindrical through hole 107a1. In the first cylinder 107a, the
first eccentric portion 104b and the first piston 105a are disposed in the through hole
107a1 to form the first compression chamber 106a. The upper bearing 109a and an
intermediate plate 110 defining the first compression chamber 106a in the vertical
direction in the first cylinder 107a are disposed. The upper bearing 109a and the
25 intermediate plate 110 close the through hole in the first cylinder 107a. The first
compression chamber 106a is a closed cylindrical space. A first inlet refrigerant pipe
108a is connected to the first cylinder 107a via the through hole 107a1.
[0024]
10
As in the case of Fig. 4, a second piston (not illustrated) is provided on the
second eccentric portion 104c. The second piston has a vane partitioning a second
compression chamber. The second piston is called also as a rolling piston.
[0025]
The second eccentric portion 104c and the second piston 5 are disposed in a
second cylinder 107b having a cylindrical through hole, under the first cylinder 107a.
In the second cylinder 107b, the second eccentric portion 104c and the second piston
are disposed in the through hole, to thereby form the second compression chamber.
The intermediate plate 110 and a lower bearing 109b defining the second
10 compression chamber in the vertical direction in the second cylinder 107b are
disposed. The intermediate plate 110 and the lower bearing 109b close the through
hole in the second cylinder 107b. The second compression chamber is a closed
cylindrical space. A second inlet refrigerant pipe 108b is connected to the second
cylinder 107b via the through hole.
15 [0026]
The upper bearing 109a covering the upper end face of the first cylinder 107a
defines the upper wall of the first compression chamber 106a, while holding the
crankshaft 104 such that the crankshaft can slide.
[0027]
20 The lower bearing 109b covering the lower end face of the second cylinder
107b defines the lower wall of the second compression chamber, while holding the
crankshaft 104 such that the crankshaft can slide.
[0028]
The intermediate plate 110 disposed between the first cylinder 107a and the
25 second cylinder 107b defines the lower wall of the first compression chamber 106a
and the upper wall of the second compression chamber, and partitions between the
first compression chamber 106a and the second compression chamber.
[0029]
The inlet ports of both the first inlet refrigerant pipe 108a and the second inlet
30 refrigerant pipe 108b are inserted upward into a suction muffler 113. The refrigerant
11
pipe 204 of the refrigeration cycle circuit is inserted downward into and connected to
the suction muffler 113 such that refrigerant flows thereto. The suction muffler 113 is
fixed to the outer periphery of the sealed container 101.
[0030]

Refrigerating machine oil is accumulated at the bottom of the sealed container
101. The refrigerating machine oil accumulated at the bottom is suctioned through a
hollow hole provided in the crankshaft 104 by the rotation of the crankshaft 104, in the
manner of a centrifugal pump using the rotation of the crankshaft 104. The
10 suctioned refrigerating machine oil passes through an oil supply hole, which extends
from the hollow hole in the crankshaft 104 toward the outer periphery to circulate
through the sliding parts. In this manner, the mechanical parts are sealed with the
refrigerating machine oil. Therefore, the sliding parts, namely, the crankshaft 104,
the first piston 105a, the second piston, the first cylinder 107a, the second cylinder
15 107b, the upper bearing 109a, the lower bearing 109b, and the intermediate plate 110
are not in direct contact with each other. This prevents damages, and prevents
leakage of refrigerant.
[0031]
An oil separator (not illustrated) is fitted to an upper portion of the crankshaft
20 104. The oil separator prevents the refrigerating machine oil from flowing out of the
twin rotary compressor 100 through a discharge pipe 112 together with the refrigerant
to be discharged. The oil separator closes the flow path to block a fluid mixture of
refrigerant and refrigerating machine oil flowing toward the discharge pipe 112, and
separates the refrigerant and the refrigerating machine oil from each other through
25 collision, thereby preventing the refrigerating machine oil from flowing out of the twin
rotary compressor 100.
[0032]
In the twin rotary compressor 100, the crankshaft 104 fixed to the rotor 103b of
the motor portion is rotated by the electric motor 103. Accordingly, the first eccentric
30 portion 104b and the second eccentric portion 104c, and the first piston 105a and the
12
second piston respectively attached to the first eccentric portion 104b and the second
eccentric portion 104c rotate eccentrically. Then, the volume of the first compression
chamber 106a and the second compression chamber partitioned by the vane 105a1
is reduced, so that the refrigerant is compressed to a high pressure. Each of the first
compression chamber 106a and the second compression chamber 5 is provided with a
discharge valve that opens when the pressure reaches a predetermined pressure or
higher. When the discharge valve opens, high-temperature and high-pressure gas
refrigerant is discharged into the sealed container 101. The compressed gas
refrigerant passes through the discharge pipe 112, and is discharged into the
10 refrigeration cycle circuit outside the twin rotary compressor. The working refrigerant
is, for example, R410A refrigerant.
[0033]

As illustrated in Fig. 1, the injection flow path 205 injects refrigerant to each of
15 the first compression chamber 106a and the second compression chamber from the
separator 207 disposed on the refrigerant pipe 204 upstream of the evaporator 203,
and more specifically, upstream of the expansion valve 202 in the refrigerant flowing
direction in the refrigeration cycle circuit.
[0034]
20 As illustrated in Fig. 2, the injection flow path 205 includes the first injection
hole 205a1, the second injection hole 205a2, a third injection hole 205a3, a fourth
injection hole 205a4, the first common hole 205f1, a second common hole 205f2, a
bypass pipe 205b, a first injection pipe 205c, a second injection pipe 205d, and an
injection muffler 205e.
25 [0035]
As illustrated in Fig. 3, the first injection hole 205a1 and the second injection
hole 205a2 are formed in the first compression chamber 106a by removing a part of
the upper bearing 109a serving as the partition unit. The first injection hole 205a1
and the second injection hole 205a2 allow the injection refrigerant to be injected from
30 the inside of the upper bearing 109a into the first compression chamber 106a.
13
[0036]
The first injection hole 205a1 and the second injection hole 205a2 are formed
in the positions equally spaced from the center of the first cylinder 107a. More
specifically, the first injection hole 205a1 and the second injection hole 205a2 are
formed adjacent to the inner radial boundary of the first cylinder 5 107a. More
preferably, the first injection hole 205a1 and the second injection hole 205a2 are
formed to be inscribed in the inner radial boundary of the first cylinder 107a.
Accordingly, as will be described below, at least one of the first injection hole 205a1
and the second injection hole 205a2 is always open to the first compression chamber
10 106a.
[0037]
The third injection hole 205a3 and the fourth injection hole 205a4 are formed in
the second compression chamber by removing a part of the lower bearing 109b
serving as the partition unit. The third injection hole 205a3 and the fourth injection
15 hole 205a4 allow the injection refrigerant to be injected from the inside of the lower
bearing 109b into the second combustion chamber.
[0038]
The third injection hole 205a3 and the fourth injection hole 205a4 are formed in
the positions equally spaced from the center of the second cylinder 107b. More
20 specifically, the third injection hole 205a3 and the fourth injection hole 205a4 are
formed adjacent to the inner radial boundary of the second cylinder 107b. More
preferably, the third injection hole 205a3 and the fourth injection hole 205a4 are
formed to be inscribed in the inner radial boundary of the second cylinder 107b.
Thus, similar to the first injection hole 205a1 and the second injection hole 205a2, at
25 least one of the third injection hole 205a3 and the fourth injection hole 205a4 is
always open to the second compression chamber.
[0039]
As illustrated in Fig. 4, the relationship of the positions of the first injection hole
205a1 and the second injection hole 205a2 relative to the hole diameters of the first
30 injection hole 205a1 and the second injection hole 205a2, the outside diameter of the
14
first piston 105a, and the inside diameter of the first cylinder 107a is appropriately set.
Thus, at least either of the first injection hole 205a1 and the second injection hole
205a2 is always open. Here, a description will be given of the configuration inside
the first cylinder. The same applies to the configuration inside the second cylinder.
5 [0040]
In Embodiment 1, the inside diameter of the first cylinder 107a is 50 mm. The
outside diameter of the first piston 105a is 32 mm. The two first and second injection
holes 205a1 and 205a2 are provided. The hole diameter of each of the first injection
hole 205a1 and the second injection hole 205a2 is 4 mm. The distance from the
10 center of the cylinder to the hole center of each of the first injection hole 205a1 and
the second injection hole 205a2 is 22.9 mm. The first injection hole 205a1 and the
second injection hole 205a2 are respectively located at a phase of 270 and a phase
of 180 in the counterclockwise direction relative to the position of the vane 105a1
defined as 0.
15 [0041]
As illustrated in Fig. 6, a chamfered rounded portion 105a3 is formed on the
inner side of the inner radial boundary of the first piston 105a, on a sliding surface
105a2 of the first piston 105a relative to the upper bearing 109a. Further, all of the
first injection hole 205a1 and the second injection hole 205a2 are formed on the
20 radially outer side of the inner radial boundary of the first piston 105a, on the sliding
surface 105a2 of the first piston 105a relative to the upper bearing 109a. This
prevents injection of the injection refrigerant from the first injection hole 205a1 and the
second injection hole 205a2 into the center hole of the first piston 105a.
[0042]
25 As illustrated in Figs. 2, 3, and 5, the first common hole 205f1 is a straight
horizontal hole formed by hollowing out a part of the upper bearing 109a serving as
the partition unit. The first common hole 205f1 has an opening in the side surface of
the upper bearing 109a such that the first injection pipe 205c is connected thereto.
The distal end of the first common hole 205f1 is closed. The first common hole
30 205f1 communicates with the first injection hole 205a1 and the second injection hole
15
205a2. The single first common hole 205f1 is provided for a group of the first
injection hole 205a1 and the second injection hole 205a2. The first common hole
205f1 is formed on the center side of the first cylinder 107a relative to a tangent to the
inner circumference of the first cylinder 107a.
5 [0043]
The second common hole 205f2 is a straight horizontal hole formed by
hollowing out a part of the lower bearing 109b serving as the partition unit. The
second common hole 205f2 has an opening in the side surface of the lower bearing
109b such that the second injection pipe 205d is connected thereto. The distal end
10 of the second common hole 205f2 is closed. The second common hole 205f2
communicates with the third injection hole 205a3 and the fourth injection hole 205a4.
The single second common hole 205f2 is provided for a group of the third injection
hole 205a3 and the fourth injection hole 205a4. The second common hole 205f2 is
formed on the center side of the second cylinder 107b relative to a tangent to the
15 inner circumference of the second cylinder 107b.
[0044]
As illustrated in Figs. 1 and 2, the bypass pipe 205b is connected to the
refrigerant pipe 204 of the refrigeration cycle circuit, and is connected to the injection
muffler 205e by inserting its end downward therein.
20 [0045]
The first injection pipe 205c has an inlet port inserted upward into the injection
muffler 205e, and is connected to the first common hole 205f1 to supply refrigerant to
the first injection hole 205a1 and the second injection hole 205a2.
[0046]
25 The second injection pipe 205d has an inlet port inserted upward into the
injection muffler 205e, and is connected to the second common hole 205f2 to supply
refrigerant to the third injection hole 205a3 and the third injection hole 205a3. The
second injection pipe 205d is connected to the sealed container 101 at a point lower
than the point at which the first injection pipe 205c is connected, and therefore is
30 longer than the first injection pipe 205c.
16
[0047]
The injection muffler 205e is disposed between the bypass pipe 205b and each
of the first injection pipe 205c and the second injection pipe 205d. The injection
muffler 205e has a greater inside diameter than the first injection pipe 205c and the
second injection pipe 205d. Thus, the first injection pipe 205c 5 and the second
injection pipe 205d are connected at two points to the circular bottom of the injection
muffler 205e.
[0048]
Similar to the suction muffler 113, the injection muffler 205e is fixed to the outer
10 periphery of the sealed container 101. The volume of the injection muffler 205e is
based on the relationship between suction refrigerant and injection refrigerant.
[0049]

Fig. 7 is an explanatory view illustrating the open state of the first injection hole
15 205a1 and the second injection hole 205a2 in accordance with the eccentric motion of
the first piston 105a, in the range of 0 to 360 according to Embodiment 1 of the
present disclosure. The following describes the state during operation of the first
piston 105a. Note that the same applies to the second piston.
[0050]
20 First, when the first piston 105a is located at 0 to 135 in the counterclockwise
direction relative to the position of the vane 105a1 defined as 0, both the first
injection hole 205a1 and the second injection hole 205a2 are open. Therefore, the
injection refrigerant flows into the first compression chamber 106a from both the first
injection hole 205a1 and the second injection hole 205a2.
25 [0051]
Subsequently, when the first piston 105a is located at 135 to 225 in the
counterclockwise direction relative to the position of the vane 105a1 defined as 0,
the first injection hole 205a1 is closed by being covered with the sliding surface 105a2
of the first piston 105a. The second injection hole 205a2 remains open. Therefore,
17
the injection refrigerant flows into the first compression chamber 106a only from the
second injection hole 205a2.
[0052]
Then, when the first piston 105a is located at 225 to 315 in the
counterclockwise direction relative to the position of the vane 105a1 5 defined as 0,
the second injection hole 205a2 is closed by being covered with the sliding surface
105a2 of the first piston 105a. The volume of the closed first compression chamber
106a is gradually reduced, so that high-temperature and high-pressure gas refrigerant
is discharged from a discharge hole 107a3 when the pressure exceeds a
10 predetermined pressure. Meanwhile, the first injection hole 205a1 is open to the
next first compression chamber 106a such that the injection refrigerant flows thereto.
In this manner, either of the first injection hole 205a1 and the second injection hole
205a2 is open to the first cylinder 107a, regardless of the eccentric motion of the first
piston 105a.
15 [0053]
The refrigerant having flowed from the refrigeration cycle circuit into the
injection flow path 205 flows into the injection muffler 205e via the bypass pipe 205b.
The refrigerant having flowed into the injection muffler 205e is supplied from the
injection muffler 205e to each of the first injection pipe 205c and the second injection
20 pipe 205d. The refrigerant that has supplied to the first injection pipe 205c passes
through the first common hole 205f1 of the twin rotary compressor 100, and is
injected as liquid or gas refrigerant from the first injection hole 205a1 and the second
injection hole 205a2 into the first compression chamber 106a. The refrigerant that
has supplied to the second injection pipe 205d passes through the second common
25 hole 205f2 of the twin rotary compressor 100, and is injected as liquid or gas
refrigerant from the third injection hole 205a3 and the fourth injection hole 205a4 into
the second compression chamber.
[0054]
In this step, the pressure inside the injection muffler 205e is an intermediate
30 pressure between the injection pressure from the refrigeration cycle circuit and the
18
pressures of the first injection pipe 205c and the second injection pipe 205d supplied
to the first compression chamber 106a and the second compression chamber.
Therefore, leakage of refrigerant due to the differential pressure between the first
compression chamber 106a and the second compression chamber does not easily
5 occur.
[0055]
The pressures of the first injection pipe 205c and the second injection pipe
205d vary in accordance with the phases of the first piston 105a and the second
piston. However, the first injection pipe 205c and the second injection pipe 205d are
10 connected to the bypass pipe 205b via the injection muffler 205e whose internal
pressure is maintained at the intermediate pressure. Therefore, the pressure of the
bypass pipe 205b is maintained constant. Thus, the refrigerant is stably injected
from the injection flow path 205, and the loss is small.
[0056]
15
In the case of a related-art twin rotary compressor having a single injection
hole, there is a period in which the injection hole is closed by an end face of a piston
passing the injection hole. Therefore, there is a phase in which the flow of injection
refrigerant is stopped. If the injection hole is provided only at 270, the injection hole
20 is open in the range of 0 to 18 and 162 to 360. In this case, in the period of 19
to 161, the injection hole is closed to prevent the injection refrigerant from flowing
into a compression mechanism unit, so that the injection effect cannot be expected.
[0057]
Meanwhile, in Embodiment 1, either of the two first and second injection holes
25 205a1 and 205a2 is always open to the first compression chamber 106a.
Accordingly, the flow of injection refrigerant is not inhibited, so that the injection effect
is improved. The preferable open state of the first injection hole 205a1 and the
second injection hole 205a2 is a fully open state. If either of the first injection hole
205a1 and the second injection hole 205a2 is always fully open, the injection effect is
19
further improved. The same applies to the relationship between the third injection
hole 205a3 and the fourth injection hole 205a4.
[0058]
Further, the two first and second injection holes 205a1 and 205a2 are disposed
with an appropriate distance therebetween, so that the pulsation 5 of the refrigerant
flowing back from the first injection hole 205a1 and the second injection hole 205a2 is
reflected by the first piston 105a, thereby reducing leakage of the refrigerant from the
first compression chamber 106a to the suction chamber. The same applies to the
relationship between the third injection hole 205a3 and the fourth injection hole
10 205a4.
[0059]
If the opening section of one injection hole of the first injection hole 205a1, the
second injection hole 205a2, the third injection hole 205a3, and the fourth injection
hole 205a4 is longer, the flow rate of injection refrigerant is increased. Thus, the
15 injection effect is increased. In order to geometrically obviously increase the opening
section, the injection hole may be located as far away from the center of the cylinder
as possible. However, if the injection hole is located on the outer side of the inner
circumference of the cylinder, the injection flow path 205 is closed by the inner
circumferential wall surface of the cylinder, so that the injection effect is reduced.
20 Further, if the injection hole inhibits formation of the corner between the inner
periphery of the cylinder and the bearing end face, the sealing property by the corner
of the piston is reduced, so that the compressor efficiency is reduced. The position
of the outer circumference of the injection hole closest to the inner circumference of
the cylinder is preferably located inwardly by approximately 0.1 mm to 3 mm
25 therefrom.
[0060]
In the case where the plurality of injection holes are located as far away from
the center of the cylinder as possible, the distances of the respective injection holes
from the center of the cylinder are preferably substantially the same. Further, the
30 common hole communicating with two injection holes is preferably straight and shifted
20
from a tangent to the inner circumference of the cylinder toward the center of the
cylinder. Thus, the common hole can communicate with two injection holes with a
simple configuration. Each of the first common hole 205f1 and the second common
hole 205f2 in Embodiment 1 is straight and shifted from the inner circumference of the
cylinder toward the center of the cylinder, and the distance to 5 the center of the
cylinder is 16.2 mm.
[0061]
When the inside diameter and the chamfering amount of the inside edge of the
piston are appropriately selected, the injection holes and the center hole inside the
10 piston never communicate with each other. This reduces the flow of high pressure
refrigerant from the injection flow path 205 into the center hole inside the piston, so
that the injection effect is increased. In Embodiment 1, the inside diameter of the
piston is 22 mm while the outside diameter thereof is 32 mm. The chamfering
amount of the inside edge of the piston is 0.5 mm in the radial direction, and 0.2 mm
15 in the height direction. If the chamfering amount in the height direction is set to be
greater than that in the radial direction, it is possible to further reduce the flow of highpressure
refrigerant into the injection flow path 205.
[0062]
As described above, since the plurality of injection holes such as the first
20 injection hole 205a1, the second injection hole 205a2, the third injection hole 205a3,
and the fourth injection hole 205a4 are provided, the total opening area for the
injection refrigerant to the compression chamber is increased. This allows a greater
amount of injection refrigerant to flow into the compression chamber. Further, the
injection pipe inserted from the outside of the sealed container 101 into a
25 compression chamber is provided only one for each compression chamber.
According to Embodiment 1, although a plurality of injection holes are provided for
each compression chamber, it is not necessary to provide a plurality of injection
pipes. This allows greater freedom in designing the exterior of the sealed container
and the periphery of the compression mechanism unit.
30 [0063]
21
The intersection between each of the injection holes such as the first injection
hole 205a1, the second injection hole 205a2, the third injection hole 205a3, and the
fourth injection hole 205a4, and each of the common holes is located on the inner
side of the inner circumference of the cylinder. The intersection is formed by one
injection hole and one common hole intersecting in a T shape. 5 However, the hole
corresponding to the vertical part of the T shape may be either the injection hole or
the common hole. However, at least one of the two injection holes closer to the inlet
of the common hole corresponds to the vertical part of the T-shape. In Embodiment
1, all the injection holes are arranged as holes corresponding to the vertical part of
10 the T-shape.
[0064]
The injection holes such as the first injection hole 205a1, the second injection
hole 205a2, the third injection hole 205a3, and the fourth injection hole 205a4 may
have a circular shape, or a non-circular shape such as an oval shape. If the injection
15 holes have an oval shape, the long side is preferably aligned with the direction of a
tangent to the inner circumference of the cylinder to secure the communication
section. In Embodiment 1, the injection holes have a circular shape.
[0065]
The plurality of injection holes may not have the same diameter. If one of the
20 injection holes has a greater diameter, it is possible to selectively change the
distribution of the injection refrigerant in the compression chamber. For example, if
the injection hole located at a phase closer to the vane 105a1 has a greater diameter,
the amount of injection refrigerant that cools the vane 105a1 is increased. This
reduces thermal expansion of the vane 105a1, so that the twin rotary compressor 100
25 with high reliability can be provided.
[0066]

Fig. 8 is an explanatory view illustrating a transverse section where the first
injection hole 205a1 and the second injection hole 205a2 open to the first
30 compression chamber 106a are visible according to Modification Example 1 of
22
Embodiment 1 of the present disclosure. In Modification Example 1, the same
features as those of Embodiment 1 will not be described, and only the characteristic
features will be described.
[0067]
As illustrated in Fig. 2, the injection refrigerant flows into 5 the upper bearing
109a via the first injection pipe 205c. An injection refrigerant pressure Pinj is the
intermediate pressure between the suction pressure Ps and the discharge pressure
Pd. Here, Ps = 0.5 MPaG; Pd = 4.0 MPaG; and Pinj = 1.5 MPaG. As illustrated in
Fig. 8, the injection refrigerant that has flowed into the first cylinder 107a passes
10 through the first common hole 205f1, and is injected from the first injection hole 205a1
and the second injection hole 205a2 into the first compression chamber 106a. Here,
the first injection hole 205a1 and the second injection hole 205a2 are located on the
inner side of the inner circumference of the first cylinder 107a. In Modification
Example 1, the inside diameter of the first cylinder 107a is 50 mm. The hole
15 diameter of the first common hole 205f1 is 3 mm. The distance from the center of
the first cylinder 107a to the hole center of each of the first injection hole 205a1 and
the second injection hole 205a2 is 22.5 mm. The outside diameter of the first piston
105a is 42 mm. The inside diameter of the first piston 105a is 35 mm. The first
injection hole 205a1 has a hole diameter of 2 mm, and is located at a phase of 270
20 in the counterclockwise revolving direction of the first piston 105a relative to the vane
105a1 defined as 0. Further, the second injection hole 205a2 has a hole diameter
of 3 mm, and is located at a phase of 280. The mass of refrigerant discharged from
the twin rotary compressor 100 is increased due to the injection refrigerant, so that
the heating capacity of the refrigeration cycle device 200 is improved. Further, the
25 injection refrigerant has a lower temperature than the discharge refrigerant.
Therefore, the sliding parts such as the vane 105a1 are cooled, and their thermal
expansion is reduced, thereby improving the reliability of the twin rotary compressor
100.
[0068]
30
23
According to Embodiment 1, the twin rotary compressor 100 includes the
electric motor 103 that includes the stator 103a and the rotor 103b. The twin rotary
compressor 100 includes the crankshaft 104 that includes the first eccentric portion
104b and the second eccentric portion 104c provided on the main shaft 104a fixed to
the rotor 103b, and that is rotated by the electric motor 103. 5 The twin rotary
compressor 100 includes the first piston 105a and the second piston provided on the
first eccentric portion 104b and the second eccentric portion 104c. The twin rotary
compressor 100 includes the first cylinder 107a and the second cylinder 107b having
the cylindrical through hole 107a1 in which the first eccentric portion 104b or the
10 second eccentric portion 104c and the first piston 105a or the second piston are
disposed to form the first compression chamber 106a or the second compression
chamber. The twin rotary compressor 100 includes the injection flow path 205
through which injection refrigerant is injected into the first compression chamber 106a
and the second compression chamber from the refrigerant pipe 204 upstream of the
15 evaporator 203 in the refrigerant flowing direction in the refrigeration cycle circuit.
The twin rotary compressor 100 includes the upper bearing 109a, the lower bearing
109b, and the intermediate plate 110 serving as the partition unit that close the
through holes in the first cylinder 107a or the second cylinder. The injection flow
path 205 has the plurality of first, second, third, and fourth injection holes 205a1,
20 205a2, 205a3, and 205a4 for injecting the injection refrigerant from the inside of the
upper bearing 109a, the lower bearing 109b, or the intermediate plate 110 into the
first compression chamber 106a or the second compression chamber, and the first
common hole 205f1 and the second common hole 205f2 formed inside the upper
bearing 109a, the lower bearing 109b, or the intermediate plate 110 and
25 communicating with the plurality of first, second, third, and fourth injection holes
205a1, 205a2, 205a3, and 205a4.
[0069]
According to this configuration, the opening area for the injection refrigerant to
be injected into the first compression chamber 106a and the second chamber is
30 increased with a simple configuration. Further, the injection flow path 205 can
24
always communicate with the first compression chamber 106a and the second
compression chamber. Accordingly, the injection refrigerant always flows into the
first compression chamber 106a and the second compression chamber, regardless of
the eccentric motion of the first piston 105a and the second piston. Thus, the
amount of refrigerant discharged is increased, so that the injection effect 5 is achieved.
Also, the sliding parts are always cooled, so that the reliability is increased.
[0070]
According to Embodiment 1, at least one injection hole of the plurality of first,
second, third, and fourth injection holes 205a1, 205a2, 205a3, and 205a4 is always
10 open to the first compression chamber 106a and the second compression chamber.
[0071]
According to this configuration, the injection flow path 205 can always
communicate with the first compression chamber 106a and the second compression
chamber, regardless of the eccentric motion of the first piston 105a and the second
15 piston.
[0072]
According to Embodiment 1, the plurality of first, second, third, and fourth
injection holes 205a1, 205a2, 205a3, and 205a4 are formed in positions equally
spaced from the centers of the first cylinder 107a and the second cylinder 107b.
20 [0073]
According to this configuration, the opening section of each injection hole is
increased, so that the injection flow rate is increased. Thus, the injection effect is
further increased.
[0074]
25 According to Embodiment 1, the plurality of first, second, third, and fourth
injection holes 205a1, 205a2, 205a3, and 205a4 are formed adjacent to the inner
radial boundary of the first and second cylinders 107a and107b.
[0075]
25
According to this configuration, the opening section of each injection hole is
further increased, so that the injection flow rate is increased. Thus, the injection
effect is further increased.
[0076]
According to Embodiment 1, the plurality of first, second, 5 third, and fourth
injection holes 205a1, 205a2, 205a3, and 205a4 are formed to be inscribed in the
inner radial boundary of the first and second cylinders 107a and107b.
[0077]
According to this configuration, the opening section of each injection hole is
10 maximized, so that the injection flow rate is increased. Thus, the injection effect is
further increased.
[0078]
According to Embodiment 1, the common hole 205f1 and the second common
hole 205f2 are respectively formed on the center side of the first cylinder 107a and
15 the second cylinder 107b relative to tangents to the inner circumference of the first
cylinder 107a and the second cylinder 107b.
[0079]
According to this configuration, each of the first common hole 205f1 and the
second common hole 205f2 can communicate with a plurality of injection holes, with a
20 simple structure.
[0080]
According to Embodiment 1, all of the first, second, third, and fourth injection
holes 205a1, 205a2, 205a3, and 205a4 are formed on the radially outer side of the
inner radial boundary of the first piston 105a and the second piston, on the sliding
25 surface 105a2 of the first piston 105a and the second piston relative to the upper and
lower bearings 109a and 109b and the intermediate plate 110.
[0081]
According to this configuration, the injection refrigerant does not leak into the
center holes of the first piston 105a and the second piston, so that the injection
30 refrigerant is not wasted.
26
[0082]
According to Embodiment 1, the first common hole 205f1 and the second
common hole 205f2 are straight.
[0083]
According to this configuration, machining is easy, and the injection 5 flow path
205 can be formed with a simple structure. The first common hole 205f1 and the
second common hole 205f2 may not be straight. For example, the first common
hole 205f1 and the second common hole 205f2 may have other shapes such as a
curved shape, the shape of a straight line bent in the middle, and a meandering
10 shape.
[0084]
According to Embodiment 1, the single first common hole 205f1 and the single
second common hole 205f2 are provided for the upper bearing 109a, the lower
bearing 109b, and the intermediate plate 110.
15 [0085]
According to this configuration, the injection flow path 205 can be formed with a
simple configuration, while reducing the man-hours for machining, and allowing easier
machining.
[0086]
20 According to Embodiment 1, the partition unit in which the common hole and
the plurality of injection holes are formed includes the upper bearing 109a covering an
end face of the first cylinder 107a or the lower bearing 109b covering an end face of
the second cylinder 107b.
[0087]
25 According to this configuration, the opening area for the injection refrigerant to
be injected into the first compression chamber 106a and the second chamber is
increased with a simple configuration. Further, the injection flow path 205 can
always communicate with the first compression chamber 106a and the second
compression chamber.
30 [0088]
27
According to Embodiment 1, the refrigeration cycle device 200 includes the
twin rotary compressor 100 described above.
[0089]
According to this configuration, in the refrigeration cycle device 200 including
the twin rotary compressor 100, the injection refrigerant always flows 5 into the first
compression chamber 106a and the second compression chamber, regardless of the
eccentric motion of the first piston 105a and the second piston. Thus, the amount of
refrigerant discharged is increased, so that the injection effect is achieved. Also, the
sliding parts are always cooled, so that the reliability is increased.
10 [0090]
According to Embodiment 1, the refrigeration cycle device 200 includes the
control valve 208 that is disposed halfway along the injection flow path 205 on the
upstream side of the twin rotary compressor 100 in the injection refrigerant flowing
direction, and that controls the flow rate of the injection refrigerant.
15 [0091]
According to this configuration, the control valve 208 regulates the flow rate of
the injection refrigerant, whereby the optimum injection effect is achieved.
[0092]
Embodiment 2
20 Fig. 9 is an explanatory view illustrating a longitudinal section of the
compression mechanism unit of the twin rotary compressor 100 according to
Embodiment 2 of the present disclosure. Fig. 10 is an explanatory view illustrating a
transverse section of the intermediate plate 110 in which the first common hole 205f1,
the first injection hole 205a1, the second injection hole 205a2, the third injection hole
25 205a3, and the fourth injection hole 205a4 are formed according to Embodiment 2 of
the present disclosure. In Embodiment 2, the same features as those of
Embodiment 1 will not be described, and only the characteristic features will be
described.
[0093]
28
As illustrated in Figs. 9 and 10, the injection flow path 205 may be disposed in
the intermediate plate 110. That is, the single first common hole 205f1 and the first
injection hole 205a1, the second injection hole 205a2, the third injection hole 205a3,
and the fourth injection hole 205a4 are formed in the intermediate plate 110 serving
as the partition unit. Since the intermediate plate 110 is disposed 5 between the first
cylinder 107a and the second cylinder 107b, a group of the first injection hole 205a1
and the second injection hole 205a2 and a group of the third injection hole 205a3 and
the fourth injection hole 205a4 are made to communicate with the single first common
hole 205f1. Further, if the intersection between the first common hole 205f1 and
10 each injection hole is formed in a cross shape, the injection flow path 205 can be
formed with a simpler configuration. In Embodiment 2, all the intersections are
formed in a cross shape.
[0094]

15 Fig. 11 is an explanatory view illustrating a transverse section of the
intermediate plate 110 in which the first common hole 205f1, the second common
hole 205f2, the first injection hole 205a1, the second injection hole 205a2, the third
injection hole 205a3, and the fourth injection hole 205a4 are formed according to
Modification 2 of Embodiment 2 of the present disclosure. In Modification 2, the
20 same features as those of Embodiment 1 will not be described, and only the
characteristic features will be described.
[0095]
As illustrated in Fig. 11, the intermediate plate 110 is disposed between the first
cylinder 107a and the second cylinder 107b. Accordingly, a group of the first and
25 second injection holes 205a1 and 205a2 and the first common hole 205f1 and a
group of the third and fourth injection holes 205a3 and 205a4 and the second
common hole 205f2 are formed in the single intermediate plate 110. Since the
injection holes and the common holes are formed in the single intermediate plate 110,
the injection flow path 205 can be formed with a simpler configuration.
30 [0096]
29

According to Embodiment 2, the two first and second eccentric portions 104b
and 104c, the two first and second pistons 105a, and the two first and second
cylinders 107a and 107b are provided. The partition unit in which the common holes
and the injection holes are formed includes the intermediate 5 plate 110 disposed
between the two first and second cylinders 107a and 107b.
[0097]
According to this configuration, the injection flow path 205 can be formed with a
simpler configuration.
10 [0098]
According to Embodiment 2, the common hole formed in the intermediate plate
110 communicates commonly with the plurality of first, second, third, and fourth
injection holes 205a1, 205a2, 205a3, and 205a4 for injecting the injection refrigerant
into the first compression chamber 106a and the second compression chamber in the
15 two first and second cylinders 107a and 107b.
[0099]
According to this configuration, the injection flow path 205 can be formed with a
simpler configuration, while further reducing the man-hours for machining.
[0100]
20 Embodiment 3
Fig. 12 is an explanatory view illustrating a transverse section where the first
injection hole 205a1 and the second injection hole 205a2 open to the first
compression chamber 106a are visible according to Embodiment 3 of the present
disclosure. In Embodiment 3, the same features as those of Embodiments 1 and 2
25 will not be described, and only the characteristic features will be described.
[0101]
As illustrated in Fig. 12, the inside diameter of the first cylinder 107a is 60 mm.
The outside diameter of the first piston 105a is 44 mm. The two first and second
injection holes 205a1 and 205a2 are provided. The hole diameter of each of the first
30 injection hole 205a1 and the second injection hole 205a2 is 2 mm. The distance
30
from the center of the first cylinder 107a to the hole center of each of the first injection
hole 205a1 and the second injection hole 205a2 is 26 mm. The first injection hole
205a1 is located at a phase of 30 in the counterclockwise direction relative to the
position of the vane 105a1 defined as 0. The second injection hole 205a2 is
located at a phase of 330 in the counterclockwise direction relative 5 to the position of
the vane 105a1 defined as 0. The angle of a suction hole 107a2 into which noninjection
refrigerant flows is 30. The hole diameter of the suction hole 107a2 is 10
mm. The length of the suction hole 107a2 extending through the first cylinder 107a
is 20 mm. An injection refrigerant pressure Pinj is the intermediate pressure
10 between the suction pressure Ps and the discharge pressure Pd. Here, Ps = 0.5
MPaG; Pd = 4.0 MPaG; and Pinj = 1.5 MPaG.
[0102]
The opening section of the first injection hole 205a1 is -345 to -75. That is,
the first injection hole 205a1 is open before a phase of 15 where the first piston 105a
15 passes through the suction hole 107a2 to form the first compression chamber 106a.
Further, the phase at which the internal pressure of the first compression chamber
106a is higher than the injection refrigerant pressure varies depending on the
operation condition. However, under a heating operation condition of a typical twin
rotary compressor, specifically, under a condition where the compression ratio
20 representing the ratio between the absolute pressures of discharge refrigerant and
suction refrigerant is 6 to 12, the internal pressure of the first compression chamber
106a is higher than the injection refrigerant pressure in a region where the phase of
the rotation axis is 130 or greater. The first injection hole 205a1 of Embodiment 3 is
not open in the region where the phase of the rotation axis is 130 or greater, that is,
25 the internal pressure of the first compression chamber 106a is higher than the
injection refrigerant pressure. The first injection hole 205a1 communicates with the
suction hole 107a2 in a certain section.
[0103]
The opening section of the second injection hole 205a2 is 75 to 345. That
30 is, the second injection hole 205a2 is open after a phase of 15 where the first piston
31
105a passes through the suction hole 107a2 to form the first compression chamber
106a. Further, the second injection hole 205a2 is open in a region where the internal
pressure of the first compression chamber 106a is higher than the injection refrigerant
pressure. The second injection hole 205a2 never communicates with the suction
hole 107a2 for introducing the refrigerant from the refrigeration cycle 5 circuit into the
first compression chamber 106a of the first cylinder 107a.
[0104]
In the case where the first injection hole 205a1 is open before the phase where
the first compression chamber 106a is formed, the injection refrigerant hinders the
10 suction of the suction refrigerant from the main circuit of the refrigeration cycle circuit,
so that the amount of refrigerant discharged is reduced. As a result, the heating
capacity is reduced, so that the injection effect is reduced. Therefore, it is desirable
to avoid such a situation. This is referred to as a restriction A.
[0105]
15 Further, in the case where the second injection hole 205a2 is open in a region
where the internal pressure of the first compression chamber 106a is higher than the
injection refrigerant pressure, the refrigerant in the first compression chamber 106a
flows back into the injection flow path 205, so that the amount of refrigerant
discharged is reduced. As a result, the heating capacity is reduced, so that the
20 injection effect is reduced. Therefore, it is desirable to avoid such a situation. This
is referred to as a restriction B.
[0106]
To improve the injection effect, it is desirable to satisfy both the restrictions A
and B. However, to satisfy both the restrictions A and B, the injection hole needs to
25 be located near the center of the first cylinder 107a, and the hole diameter of the
injection hole needs to be reduced. In this case, the injection flow path 205 is
narrowed, so that the injection effect is reduced.
[0107]
In Embodiment 3, both the first and second injection holes 205a1 and 205a2 do
30 not satisfy both the restrictions A and B, but each injection hole satisfies only either
32
one of the restrictions. Specifically, the opening section of the first injection hole
205a1 satisfies the restriction A, but does not satisfy the restriction B. The opening
section of the second injection hole 205a2 satisfies the restriction B, but does not
satisfy the restriction A. Thus, it is possible to selectively reduce the number of
injection holes that are open in the section where the injection effect 5 is reduced, while
maximizing the length of the opening sections of the first injection hole 205a1 and the
second injection hole 205a2. Here, "maximizing the opening section of the injection
hole" means locating the injection hole as close to the inner circumferential wall
surface of the first cylinder as possible.
10 [0108]
In Embodiment 3, the opening sections of the two injection holes do not
overlap. However, the two opening sections of the two injection holes may overlap.
Specifically, the rotational angle at which the first piston 105a closes the suction hole
107a2 is presumed to be ; the rotational angle at which the internal pressure of the
15 first compression chamber 106a becomes higher than the injection refrigerant
pressure is presumed to be ; the opening section of the first injection hole 205a1 is
As to Ae; and the opening section of the second injection hole 205a2 is presumed
to be Bs to Be, the relationship As <  < Bs < Ae <  < Be may be satisfied.
In this case, either one of the two injection holes is open in the phase of less than  or
20 greater than  where the injection effect is reduced. Meanwhile, both the two
injection holes are open in the phase greater than or equal to  and less than or equal
to  where the injection effect is not reduced. Accordingly, the injection effect can be
further increased.
[0109]
25
According to Embodiment 3, at least one injection hole of the plurality of first,
second, third, and fourth injection holes 205a1, 205a2, 205a3, and 205a4 is always
closed in a section where the internal pressure of the first compression chamber 106a
and the internal pressure of the second compression chamber are higher than the
30 injection pressure of the injection flow path 205. At least another injection hole of the
33
plurality of first, second, third, and fourth injection holes 205a1, 205a2, 205a3, and
205a4 is open at a part of the section where the internal pressure of the first
compression chamber 106a and the internal pressure of the second compression
chamber are higher than the injection pressure of the injection flow path 205.
5 [0110]
According to this configuration, in the case where the first injection hole 205a1
is open before the phase where the first compression chamber 106a is formed, the
injection refrigerant hinders the suction of the suction refrigerant from the main circuit
of the refrigeration cycle circuit, so that the amount of refrigerant discharged is
10 reduced. As a result, the heating capacity is reduced, so that the injection effect is
reduced. Therefore, it is desirable to avoid such a situation in which the first
injection hole 205a1 is open before the phase where the first compression chamber
106a is formed. This is referred to as a restriction A. Further, in the case where the
second injection hole 205a2 is open in a region where the internal pressure of the first
15 compression chamber 106a is higher than the injection refrigerant pressure, the
refrigerant in the first compression chamber 106a flows back into the injection flow
path 205, so that the amount of refrigerant discharged is reduced. As a result, the
heating capacity is reduced, so that the injection effect is reduced. Therefore, it is
desirable to avoid such a situation in which the second injection hole 205a2 is open in
20 a region where the internal pressure of the first compression chamber 106a is higher
than the injection refrigerant pressure. This is referred to as a restriction B. In
Embodiment 3, the opening section of the one first injection hole 205a1 satisfies the
restriction A, but does not satisfy the restriction B. Further, the opening section of
the other second injection hole 205a2 satisfies the restriction B, but does not satisfy
25 the restriction A. Accordingly, in the section where the injection effect is reduced, it is
possible to selectively reduce the number of injection holes that are open.
Therefore, it is possible to reduce a reduction in the injection effect. Note that the
third injection hole 205a3 and the fourth injection hole 205a4 have the same
relationship as that between the first injection hole 205a1 and the second injection
30 hole 205a2.
34
[0111]
According to Embodiment 3, at least one injection hole of the plurality of first,
second, third, and fourth injection holes 205a1, 205a2, 205a3, and 205a4 never
communicates with the suction hole 107a2 for introducing the refrigerant from the
refrigeration cycle circuit into the first compression chamber 106a 5 and the second
compression chamber of the first cylinder 107a and the second cylinder 107b. At
least another injection hole of the plurality of first, second, third, and fourth injection
holes 205a1, 205a2, 205a3, and 205a4 communicates with the suction hole 107a2 in
a certain section.
10 [0112]
According to this configuration, either of the injection holes is always fully open
regardless of the eccentric motion of the first piston 105a and the second piston, so
that the injection effect is further increased.
[0113]
15 Embodiment 4
Fig. 13 is an explanatory view illustrating a transverse section where the
injection holes 205a open to the first compression chamber 106a are visible
according to Embodiment 4 of the present disclosure. In Embodiment 4, the same
features as those of Embodiments 1 to 3 will not be described, and only the
20 characteristic features will be described.
[0114]
As illustrated in Fig. 13, three or more injection holes 205a may be provided.
For example, n injection holes 205a may be provided, and n-1 or less common holes
205f may be provided to communicate with the n injection holes 205a. In
25 Embodiment 4, three injection holes 205a are provided. Two common holes 205f
are provided. The three injection holes 205a are respectively located at phases of
270, 225, and 180 in the counterclockwise direction relative to the position of the
vane 105a1 defined as 0. The two common holes 205f intersect. An end of the
one common hole 205f communicates with the upstream side of the injection flow
30 path 205 in the injection refrigerant flowing direction, and the other end of the one
35
common hole 205f is closed. Both ends of the other common hole 205f are closed.
One end of the other common hole 205f is open to the side surface of the upper
bearing 109a for reasons of machining, and therefore is covered with a cap 109a1.
One injection hole of the three injection holes 205a is formed at the position where
the two common holes 205f intersect. Thus, two injection holes 5 205a are formed in
each of the two common holes 205f. The single injection hole 205a formed at the
position where the two common holes 205f intersect is close to a connection point to
the upstream side of the injection flow path 205, so that it is possible to inject a
greater amount of injection refrigerant therethrough in the section where the greatest
10 amount of injection refrigerant is needed.
[0115]

According to Embodiment 4, the plurality of first and second common holes
205f1 and 205f2 are provided for the upper bearing 109a, the lower bearing 109b,
15 and the intermediate plate 110. Three or more injection holes are provided for each
compression chamber. The plurality of first and second common holes 205f1 and
205f2 intersect.
[0116]
According to this configuration, the injection flow path 205 can always
20 communicate with the first compression chamber 106a and the second compression
chamber.
[0117]
According to Embodiment 4, an end of one common hole of the plurality of
common holes communicates with the upstream side of the injection flow path 205 in
25 the injection refrigerant flowing direction, and the other end of the one common hole
is closed. Both ends of another common hole of the plurality of common holes are
closed.
[0118]
According to this configuration, only one common hole communicates with the
30 upstream side of the injection flow path 205 in the injection refrigerant flowing
36
direction. Accordingly, the injection flow path 205 can be simplified, so that the
injection flow path 205 can be formed with a simple structure.
[0119]
According to Embodiment 4, at least one injection hole of the plurality of
injection holes is formed at the position where the plurality of common 5 holes intersect.
[0120]
According to this configuration, it is possible to inject a greater amount of
injection refrigerant from the injection hole located at the position where the plurality
of common holes intersect, in the section where the greatest amount of injection
10 refrigerant is needed. Accordingly, the injection effect can be further improved.
[0121]
Embodiments1 to 4 of the present disclosure may be combined with each
other, or may be applied to other parts. Further, Embodiments 1 to 4 have illustrated
the twin rotary compressor. However, the present disclosure may be applied to other
15 rotary compressors such as a single rotary compressor.
Reference Signs List
[0122]
100 twin rotary compressor 101 sealed container 101a cylindrical unit
101b upper end closing unit 101c lower end closing unit 102 base 103
20 electric motor 103a stator 103b rotor 104 crankshaft 104a main shaft
104b first eccentric portion 104c second eccentric portion 104d sub shaft
105a first piston 105a1 vane 105a2 sliding surface 105a3 rounded portion
106a first compression chamber 107a first cylinder 107a1 through hole
107a2 suction hole 107a3 discharge hole 107b second cylinder 108a first
25 inlet refrigerant pipe 108b second inlet refrigerant pipe 109a upper bearing
109a1 cap unit 109b lower bearing 110 intermediate plate 112 discharge
pipe 113 suction muffler 200 refrigeration cycle device 201 condenser 202
expansion valve 203 evaporator 204 refrigerant pipe 205 injection flow path
205a injection hole 205a1 first injection hole 205a2 second injection hole
30 205a3 third injection hole 205a4 fourth injection hole 205b bypass pipe
205c first injection pipe 205d second injection pipe 205e injection muffler
205f common hole 205f1 first common hole 205f2 second common hole
206 accumulator 207 separator 208 control valve
We Claim :
[Claim 1]
A rotary compressor comprising:
an electric motor including a stator and a rotor;
a crankshaft including an eccentric portion that is provided 5 on a main shaft
fixed to the rotor, and is rotated by the electric motor;
a piston provided on the eccentric portion;
a cylinder having a cylindrical through hole in which the eccentric portion and
the piston are disposed to form a compression chamber;
an injection flow path through which injection refrigerant is injected into the
compression chamber; and
a partition unit closing the through hole in the cylinder;
wherein the injection flow path has a plurality of injection holes for injecting the
injection refrigerant from an inside of the partition unit into the compression chamber,
and a common hole formed inside the partition unit and communicating with the
plurality of injection holes.
[Claim 2]
The rotary compressor of claim 1, wherein at least one injection hole of the
plurality of injection holes is always open to the compression chamber.
20 [Claim 3]
The rotary compressor of claim 1 or 2, wherein the plurality of injection holes
are formed in positions equally spaced from a center of the cylinder.
[Claim 4]
The rotary compressor of any one of claims 1 to 3, wherein the plurality of
injection holes are formed adjacent to an inner radial boundary of the cylinder.
[Claim 5]
The rotary compressor of any one of claims 1 to 4, wherein the plurality of
injection holes are formed so as to be inscribed in an inner radial boundary of the
cylinder.
[Claim 6]
The rotary compressor of any one of claims 1 to 5, wherein the common hole is
formed on a center side of the cylinder relative to a tangent to an inner circumference
of the cylinder.
[Claim 7]
The rotary compressor of any one of claims 1 to 6, wherein all of 5 the plurality of
injection holes are formed on a radially outer side of an inner radial boundary of the
piston, on a sliding surface of the piston relative to the partition unit.
[Claim 8]
The rotary compressor of any one of claims 1 to 7,
wherein at least one injection hole of the plurality of injection holes is always
closed in a section where an internal pressure of the compression chamber is higher
than an injection pressure of the injection flow path; and
wherein at least one other injection hole of the plurality of injection holes is
open at a part of the section where the internal pressure of the compression chamber
is higher than the injection pressure of the injection flow path.
[Claim 9]
The rotary compressor of any one of claims 1 to 8,
wherein at least one injection hole of the plurality of injection holes never
communicates with a suction hole of the cylinder; and
wherein at least an other injection hole of the plurality of injection holes
communicates with the suction hole in a certain section.
[Claim 10]
The rotary compressor of any one of claims 1 to 9, wherein the common hole is
straight.
[Claim 11]
The rotary compressor of any one of claims 1 to 10, wherein the one common
hole is provided for the partition unit.
[Claim 12]
The rotary compressor of any one of claims 1 to 10,
30 wherein plural of the common holes are provided for the partition unit;
wherein three or more of the injection holes are provided for the single
compression chamber; and
wherein the plurality of common holes intersect.
[Claim 13]
The rotary compressor 5 of claim 12,
wherein an end of one common hole of the plurality of common holes
communicates with an upstream side of the injection flow path in an injection
refrigerant flowing direction, and an other end of the one common hole is closed; and
wherein both ends of an other common hole of the plurality of common holes
are closed.
[Claim 14]
The rotary compressor of claim 12 or 13, wherein at least one injection hole of
the plurality of injection holes is formed at a position where the plurality of common
holes intersect.
[Claim 15]
The rotary compressor of any one of claims 1 to 14, wherein the partition unit in
which the common hole and the plurality of injection holes are formed is a bearing
covering an end face of the cylinder.
[Claim 16]
The rotary compressor of any one of claims 1 to 15,
wherein two of the eccentric portions, two of the pistons, and two of the
cylinders are provided; and
wherein the partition unit in which the common hole and the plurality of injection
holes are formed is the intermediate plate disposed between the two cylinders.
[Claim 17]
The rotary compressor of claim 16, wherein the common hole formed in the
intermediate plate communicates commonly with the plurality of injection holes for
injecting the injection refrigerant into the compression chambers of the two cylinders.
[Claim 18]
30 A refrigeration cycle device comprising:
the rotary compressor of any one of claims 1 to 17.
[Claim 19]
The refrigeration cycle device of claim 18, further comprising:
a control valve configured to control a flow rate of the injection refrigerant and
is disposed halfway along the injection flow path on an upstream 5 side of the rotary
compressor in an injection refrigerant flowing direction.