FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
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
5 DESCRIPTION
Technical Field
[0001]
The present disclosure relates to a compressor that has a discharge
mechanism by which refrigerant is discharged and a refrigeration cycle apparatus.
10 Background Art
[0002]
Some compressor has been present in which a valve body is located in a
discharge outlet when the discharge outlet is closed and the valve body is
reciprocated by a spring to reduce dead volume. Refer, for example, to Patent
15 Literature 1.
Citation List
Patent Literature
[0003]
Patent Literature 1: Japanese Unexamined Patent Application Publication No.
20 8-319973
Summary of Invention
Technical Problem
[0004]
In the compressor described in Patent Literature 1, however, a valve body may
25 slowly open and slowly close a discharge outlet depending on the weight of the valve
body. As described above, when the valve body slowly opens and slowly closes the
discharge outlet, refrigerant leaks and high-pressure refrigerant is overly compressed,
and efficiency of the compressor is thus reduced.
[0005]
30 The present disclosure is made to avoid such inconvenience, and an object of
the present disclosure is to provide a compressor and a refrigeration cycle apparatus
in which a discharge outlet is prevented from being slowly opened and slowly closed
by a valve body to improve compression efficiency.
Solution to Problem
3
5 [0006]
A compressor according to an embodiment of the present disclosure has an
airtight container; a cylinder provided in the airtight container and in which a
compression chamber is provided in which refrigerant is compressed; a shaft bearing
provided in the airtight container and to which a discharge outlet is provided through
10 which refrigerant compressed in the compression chamber is discharged; and a
discharge mechanism that has a guide lid that is provided to the shaft bearing and
has a cylindrical portion in which a guide hole is opened, a valve body provided in the
guide hole, and a connection component that is provided in the guide hole and by
which the guide lid and the valve body are connected to each other, and is configured
15 to open and close the discharge outlet when the valve body moves in the guide hole,
in which, when an inner diameter of the cylindrical portion in a direction orthogonal to
a movement direction in which the valve body moves along the guide hole is defined
as ar, an outermost diameter of the valve body in the direction orthogonal to the
movement direction in which the valve body moves along the guide hole is defined as
20 br, and clearance between the inner diameter ar of the cylindrical portion and the
outermost diameter br of the valve body is defined as Δc, relationships described
below are satisfied: Δc = ar − br, and 1/1000 ≤ Δc/br ≤ 1/100.
Advantageous Effects of Invention
[0007]
25 According to an embodiment of the present disclosure, relationships of Δc = ar
− br and 1/1000 ≤ Δc/br ≤ 1/100 are satisfied, sealing is thus tighter between a space
around the valve body in which a connection component is located and a space
around the valve body and in the vicinity of a discharge outlet. As a result, by
effective use of differential pressure between pressure in the space around the valve
30 body in which the connection component is located and pressure in the space around
the valve body and in the vicinity of the discharge outlet, a movement speed at which
the valve body moves is increased. The discharge outlet of the compressor is
therefore prevented from being slowly opened and slowly closed and compression
efficiency is thus improved.
4
5 Brief Description of Drawings
[0008]
[Fig. 1] Fig. 1 is a schematic configuration diagram that schematically illustrates
a configuration of a compressor according to Embodiment 1.
[Fig. 2] Fig. 2 is a diagram that illustrates a state in which a valve body in a
10 discharge mechanism in the compressor according to Embodiment 1 closes a
discharge outlet.
[Fig. 3] Fig. 3 is a diagram that illustrates a state in which the valve body in the
discharge mechanism in the compressor according to Embodiment 1 opens the
discharge outlet.
15 [Fig. 4] Fig. 4 is a diagram that illustrates clearance between the valve body
and a guide hole in the compressor according to Embodiment 1.
[Fig. 5] Fig. 5 is a side view that illustrates a valve body that is T-shaped in the
compressor according to Embodiment 1.
[Fig. 6] Fig. 6 is a top view that illustrates the valve body that is T-shaped in the
20 compressor according to Embodiment 1.
[Fig. 7] Fig. 7 is a diagram that illustrates the discharge mechanism to which
the valve body that is T-shaped is attached in the compressor according to
Embodiment 1.
[Fig. 8] Fig. 8 is a diagram that illustrates a case in which a first discharge
25 mechanism and a second discharge mechanism are provided to the compressor
according to Embodiment 1.
[Fig. 9] Fig. 9 is a refrigerant circuit diagram that schematically illustrates a
configuration of a refrigerant circuit in a refrigeration cycle apparatus according to
Embodiment 2.
30 [Fig. 10] Fig. 10 is a chart that illustrates gas density in refrigerant sucked in the
compressor and gas density in refrigerant discharged from the compressor under
rated conditions of compressor operation in a typical refrigeration cycle stipulated in
ASHRAE.
[Fig. 11] Fig. 11 is a diagram that illustrates an example of a reed valve in a
5
5 compressor.
[Fig. 12] Fig. 12 is a diagram that illustrates a lift distance of the valve body in
the compressor used in the refrigeration cycle apparatus according to Embodiment 3.
Description of Embodiments
[0009]
10 A compressor according to embodiments is described below with reference to
drawings. In the drawings, the same components are described by use of the same
reference signs and not described again unless necessary. The present disclosure
may include any combination of configurations that are combinable with each other
among configurations described below in respective embodiments. In addition, a
15 relationship in size between components in the drawings may differ from actual one.
The form of components represented in the entire specification is merely an example,
and does not limit the components to the form described in the specification. In
particular, a combination of components is not limited only to that in each embodiment.
A component described in one embodiment may be applied to another embodiment.
20 In addition, pressure levels and temperature levels are not determined in relation to
particular absolute values but are relatively determined under conditions, such as
states and operation of devices. In addition, in the following description, the
longitudinal direction of an airtight container, which is an up-down direction in the
drawings, is defined as an axial direction. Also, a direction that passes through the
25 center axis in the airtight container and is perpendicular to the center axis is defined
as a radial direction.
[0010]
Embodiment 1
Fig. 1 is a schematic configuration diagram that schematically illustrates a
30 configuration of a compressor 100 according to Embodiment 1.
[0011]
The compressor 100 is described below with reference to Fig. 1. The
compressor 100 is to serve as a component in a refrigerant circuit in a refrigeration
cycle apparatus, such as a refrigerator, a freezer, a vending machine, an air-
6
5 conditioning apparatus, a refrigeration apparatus, and a water heater. Fig. 1
illustrates a rotary compressor as an example of the compressor 100. The
compressor 100 is also applicable to a scroll compressor, a reciprocating compressor,
or other airtight compressor that has a discharge valve. In addition, fluid to be
compressed by the compressor 100 is here described as refrigerant used in an
10 apparatus such as a refrigeration cycle apparatus.
[0012]
[Configuration of Compressor 100]
The compressor 100 is configured to compress sucked refrigerant and
discharge the refrigerant. The compressor 100 has an airtight container 3. The
15 airtight container 3 is formed by a lower container 1 and an upper container 2. The
airtight container 3 houses a compression mechanism unit 10 and a motor unit 20.
For example, Fig. 1 illustrates a state, as an example, in which the compression
mechanism unit 10 is housed in a lower portion of the airtight container 3 and the
motor unit 20 is housed in an upper portion of the airtight container 3. Also, a bottom
20 portion of the airtight container 3 serves as an oil reservoir in which refrigerating
machine oil is pooled. Refrigerating machine oil mainly lubricates sliding portions in
the compression mechanism unit 10.
[0013]
To the lower container 1 of the airtight container 3, a first suction pipe 31a and
25 a second suction pipe 31b, which communicate with an accumulator 300, which is
referable to Fig. 9, are connected. Respective inlet ports of the first suction pipe 31a
and the second suction pipe 31b are inserted into a suction muffler 60. The suction
inlet 50 of the first suction pipe 31a is formed at a cylinder 13. For the second
suction pipe 31b, a configuration similar to the configuration of the first suction pipe
30 31a is also used. Such a configuration of the second suction pipe 31b is formed at
another cylinder 13. The suction muffler 60 is connected to the accumulator 300
through a portion of a low-pressure pipe 155b, which is referable to Fig. 9, in a
refrigeration cycle circuit and refrigerant flows from the accumulator 300 into the
suction muffler 60. The suction muffler 60 is fixed to the outer circumference of the
7
5 airtight container 3. The compressor 100 draws refrigerant, which is gas refrigerant,
into the airtight container 3 from the accumulator 300 through the first suction pipe
31a and the second suction pipe 31b. At an upper portion of the upper container 2
of the airtight container 3, a discharge pipe 2a is connected. The compressor 100
discharges refrigerant compressed in the compression mechanism unit 10 to the
10 outside through the discharge pipe 2a. The accumulator 300 is described later.

The compression mechanism unit 10 is configured to compress refrigerant by being
driven by the motor unit 20.
[0014]
15 The compression mechanism unit 10 is configured such that the cylinder 13, a
rolling piston 16, a shaft bearing 14, a main shaft 11, an unillustrated vane, and other
component are included.
[0015]
The cylinder 13 is located in the airtight container 3, is substantially circular20 shaped in plan view at its outer circumference, and has a compression chamber 30,
which is a substantially circular-shaped space in plan view, in the inside of the
cylinder 13. The cylinder 13 has a specified height in the axial direction in side view.
The compression chamber 30 has open ends opposite to each other in the axial
direction. Also, to the cylinder 13, an unillustrated vane groove that communicates
25 with the compression chamber 30 and extends in a radial direction is provided such
that the vane groove extends through the cylinder 13 in the axial direction. The
compression chamber 30 in the cylinder 13 is a space defined by attaching the shaft
bearing 14 to one end of the cylinder 13, which is cylindrical, in a direction in which
the main shaft 11 extends and by attaching a partition plate 15 to the other end. In
30 the compression chamber 30, refrigerant is compressed.
[0016]
To the cylinder 13, an unillustrated suction port through which gas refrigerant
sucked through the first suction pipe 31a passes is also provided. The suction port
is formed such that the suction port extends through from the outer-circumferential
8
5 face of the cylinder 13 to the compression chamber 30.
[0017]
Also, to the cylinder 13, an unillustrated discharge port through which
refrigerant compressed in the compression chamber 30 is discharged from the
compression chamber 30 is also provided. The discharge port is formed by cutting a
10 portion of an edge portion of an upper end face of the cylinder 13.
[0018]
The rolling piston 16 is ring-shaped and housed in the compression chamber
30 such that the rolling piston 16 is eccentrically rotatable. The rolling piston 16 is
also fitted to, at its inner circumference portion, an eccentric shaft portion 12 of the
15 main shaft 11 such that the rolling piston 16 is slidable.
[0019]
In the unillustrated vane groove, a vane is housed. By an unillustrated vane
spring provided to a back-pressure chamber, the vane housed in the vane groove is
always pressed against the rolling piston 16. When the pressure in the airtight
20 container 3 is high and the compressor 100 start operation, on the back-pressure
chamber, which is located in the rear face of the vane, force caused by differential
pressure between high pressure in the airtight container 3 and pressure in the
compression chamber 30 acts. The vane spring is thus used, mainly when the
compressor 100 starts with no pressure difference between the inside of the airtight
25 container 3 and the inside of the compression chamber 30, to press the vane against
the rolling piston 16.
[0020]
The shape of the vane is a substantial cuboid. Specifically, the vane is a
substantial cuboid that is flat such that its circumferential length, which is also referred
30 to as thickness, is smaller than each of its radial length and its axial length.
[0021]
The shaft bearing 14 is located in the airtight container 3 and substantially
inverted T-shaped in side view. The shaft bearing 14 is fitted to a main shaft portion
11a of the main shaft 11, which is a portion upper than the eccentric shaft portion 12,
9
5 such that the main shaft 11 is slidable. The shaft bearing 14 closes one end face of
the compression chamber 30 and its vicinity that includes the vane groove of the
cylinder 13, which is an end face that faces toward the motor unit 20. To an inside
and upper portion of the shaft bearing 14, a discharge mechanism 40, which has a
valve body 41, which is referable to Fig. 2 and Fig. 3, is provided. The configuration
10 of the discharge mechanism 40 is described later.
[0022]
The suction muffler 60 is located next to the airtight container 3. The suction
muffler 60 sucks low-pressure gas refrigerant from a refrigeration cycle. The suction
muffler 60 prevents, in a case in which liquid refrigerant returns from the refrigeration
15 cycle, the liquid refrigerant from being sucked directly into the compression chamber
30 in the cylinder 13. The suction muffler 60 is connected to the suction ports in the
cylinder 13 through the first suction pipe 31a and the second suction pipe 31b. The
suction muffler 60 is fixed to the side face of the airtight container 3 by welding or
other method.
20 [0023]
High-temperature and high-pressure gas refrigerant compressed in the
compression mechanism unit 10 passes through the motor unit 20 from the discharge
outlet 45 located inside the discharge muffler 17, which is referable to Fig. 2, and is
discharged through the discharge pipe 2a to the outside of the compressor 100.
25 [0024]

The motor unit 20 is configured to drive the compression mechanism unit 10.
[0025]
The motor unit 20 is configured such that a rotor 21, a stator 22, and other
30 components are included. The stator 22 is in contact with and fixed to the inner
circumferential face of the airtight container 3. The rotor 21 is located in the inside of
the stator 22 with a gap between the rotor 21 and the stator 22.
[0026]
The stator 22 has at least a stator core of which a plurality of magnetic steel
10
5 sheets are laminated and a winding wire wound around teeth of the stator core by
concentrated winding with an insulator component between the winding wire and the
teeth. To the winding wire of the stator 22, a lead wire is also connected. The lead
wire is connected to a glass terminal provided to the upper container 2 to supply
electric power from the outside of the airtight container 3.
10 [0027]
The rotor 21 has at least a rotor core of which a plurality of magnetic steel
sheets are laminated and a permanent magnet inserted into the rotor core. To the
center of the rotor core, the main shaft portion 11a of the main shaft 11 is shrink-fitted
or press-fitted.
15 [0028]

Fig. 2 is a diagram that illustrates a state in which the valve body 41 in the
discharge mechanism 40 in the compressor 100 according to Embodiment 1 closes
the discharge outlet 45. Fig. 3 is a diagram that illustrates a state in which the valve
20 body 41 in the discharge mechanism 40 in the compressor 100 according to
Embodiment 1 opens the discharge outlet 45.
[0029]
To the shaft bearing 14, a discharge outlet 45 is also provided. The discharge
outlet 45 is provided to a flange portion of the shaft bearing 14 such that the
25 compression chamber 30 and the airtight container 3 communicate with each other.
The discharge outlet 45 is a hole that forms a passage through which refrigerant
passes when the refrigerant is discharged from the compression chamber 30 into the
airtight container 3. An opening portion of the discharge outlet 45 that faces toward
the compression chamber 30 is located at an end face of the compression chamber
30 30. Specifically, the opening portion of the discharge outlet 45 that faces toward the
compression chamber 30 is formed such that the positions of the opening portion and
an upper face of the compression chamber 30 defined in the cylinder 13 substantially
coincide with each other in plan view.
[0030]
11
5 As illustrated in Fig. 2 and Fig. 3, the discharge mechanism 40 has the valve
body 41, a spring 43, and a guide lid 46. An arrow illustrated in Fig. 2 indicates highpressure gas refrigerant of which pressure is applied from the compression chamber
30 to the valve body 41. Also, an arrow a, an arrow b, and an arrow c illustrated in
Fig. 3 indicate courses through which high-pressure gas refrigerant flow.
10 [0031]
The guide lid 46 is cylindrical and has a closure portion 46a, which is provided
close to an upper portion of the shaft bearing 14, and a cylindrical portion 46b, which
is provided inside of the shaft bearing 14. The inside of the closure portion 46a and
the inside of the cylindrical portion 46b define a guide hole 42. The closure portion
15 46a is a portion of the guide lid 46 at which a communication hole 44 is provided.
The cylindrical portion 46b is a portion of the guide lid 46 that faces toward a portion
at which the compression chamber 30 is located. The cylindrical portion 46b is
located in the shaft bearing 14. The inside of the cylindrical portion 46b and the
discharge outlet 45 communicate with each other. The lowermost end of the
20 cylindrical portion 46b is formed such that the lowermost end fits on the shape of the
valve body 41. To the lowermost end of the cylindrical portion 46b, a valve-body
seat portion 46c formed in the shaft bearing 14 is provided. The valve-body seat
portion 46c is chamfered. A face is chamfered by, for example, 2 [mm] in its height
direction and 3 [mm] in its radial direction.
25 [0032]
The valve body 41 is configured to open and close the discharge outlet 45 by
receiving pressure in the compression chamber 30 and pressure in the airtight
container 3. When the pressure in the compression chamber 30 is lower than the
pressure in the airtight container 3, the valve body 41 is pressed against the
30 discharge port and the discharge outlet 45 is closed. The valve body 41 is located
such that, when the valve body 41 closes the discharge outlet 45, an end face of the
valve body 41 that faces toward the compression chamber 30 is almost even with an
end face of the discharge outlet 45 that faces toward the compression chamber 30.
The end face of the compression chamber 30 and the end face of the valve body 41
12
5 that faces toward the compression chamber 30 thus coincide with each other at the
same plane. In other words, the valve body 41 closes an opening face of the
discharge outlet 45 that faces toward the compression chamber 30 from the inside of
the discharge outlet 45. The above expression "coincide with each other" includes a
case in which, to secure clearance, for example, the end face of the valve body 41
10 that faces toward the compression chamber 30 is only away from the corresponding
end of the discharge outlet 45 by a slight distance. For example, such a case may
be a case in which the end face of the valve body 41 that faces toward the
compression chamber 30 and the corresponding end face of the compression
chamber 30 are only away from each other by a distance of approximately one tenth
15 of a whole length of the discharge outlet 45. To increase an area at which pressure
from the compression chamber 30 is received, a dent, a groove, and other shape may
also be formed in the valve body 41 at a portion of the valve body 41 that faces
toward the compression chamber 30.
[0033]
20 On the other hand, when the pressure in the compression chamber 30 is higher
than the pressure in the airtight container 3, the valve body 41 is pushed upward by
the pressure in the compression chamber 30 and thus releases the discharge outlet
45. When the discharge outlet 45 is released, refrigerant compressed in the
compression chamber 30 is guided to the outside of the compression chamber 30.
25 [0034]
When the discharge outlet 45 opens, high-temperature and high-pressure gas
refrigerant discharged from the discharge outlet 45 is emitted into the airtight
container 3.
[0035]
30 The closure portion 46a and the cylindrical portion 46b of the guide lid 46 are
formed integrally with each other. The closure portion 46a and the cylindrical portion
46b, however, may also be formed as parts separated from each other. Also, the
cylindrical portion 46b of the guide lid 46, which is formed as a part separated from
the shaft bearing 14, may also be formed integrally with the shaft bearing 14. The
13
5 shaft bearing 14, the closure portion 46a, and the cylindrical portion 46b are formed
into two parts or three parts. To the closure portion 46a of the guide lid 46, one end
of the spring 43, which is a connection component, is attached. The one end of the
spring 43 is located in the guide hole 42 in the guide lid 46. The other end of the
spring 43 is attached to the valve body 41. The spring 43 applies spring force, which
10 is elastic force, in a direction in which the valve body 41 closes the discharge outlet
45.
[0036]
The guide hole 42 is a round-columnar-shaped space and is the inside of the
closure portion 46a of the guide lid 46 and the inside of the cylindrical portion 46b of
15 the guide lid 46. Also, the cylindrical portion 46b is located in a hole provided to the
flange portion of the shaft bearing 14. One end of the guide hole 42 that faces
toward the compression chamber 30 is formed such that the one end coincides with
the corresponding end face of the compression chamber 30 and fits on the inside wall
of the cylinder 13. Also, a lower portion of the shaft bearing 14 coincides with the
20 corresponding end face of the compression chamber 30 and the corresponding end
face of the cylinder 13. Also, a space inside the guide lid 46 may also be formed by
tooling from the side face of the flange portion of the shaft bearing 14. The guide
hole 42 may also be formed such that another component covers a flat face at an end
portion of the guide hole 42 opposite to the compression chamber 30.
25 [0037]
The one end of the guide hole 42 that faces toward the compression chamber
30 does not necessarily coincide with the corresponding end face of the compression
chamber 30, which is located under the guide hole 42, and does not necessarily fit on
the inside wall of the cylinder 13. The one end of the guide hole 42 that faces
30 toward the compression chamber 30 may also be, for example, located outside the
inside wall of the cylinder 13. In this case, a portion of the valve body 41 is in
contact with the cylinder 13 or comes close to or is in contact with an object such as
an elastic body provided on the cylinder 13. Also , the one end of the guide hole 42
that faces toward the compression chamber 30 may also be located slightly further
14
5 inside the airtight container 3 than is the corresponding end face of the compression
chamber 30. Clearance between the valve body 41 and the rolling piston 16 are
thus secured.
[0038]
Also, in a case in which the guide lid 46 is a part separate from the shaft
10 bearing 14, the guide lid 46 may also be located inside the flange portion of the shaft
bearing 14. In this case, the discharge outlet 45 has its reduced length and an
opening portion of the guide hole 42 that faces toward the compression chamber 30
is made to be an opening portion that communicates with the inside of the airtight
container 3. The valve-body seat portion 46c may also be located at the cylindrical
15 portion 46b of the guide lid 46 rather than at the shaft bearing 14.
[0039]
In the closure portion 46a of the guide lid 46, the communication hole 44, which
is round-columnar-shaped, is opened. The communication hole 44 communicates
with the inside of the airtight container 3 to which high-pressure refrigerant discharged
20 through the guide hole 42 in the guide lid 46 and the discharge outlet 45 is discharged
through the discharge muffler 17. The horizontal outer diameter of the
communication hole 44 is smaller than the horizontal outer diameter of the valve body
41. The diameter of the communication hole 44 is smaller than the inner diameter of
the guide lid 46 and is Φ6 mm in this description. The shape of the communication
25 hole 44, which is circular-shaped, may also be selected to be oval-shaped in
consideration of interference with parts around the communication hole 44. The
valve-body seat portion 46c of the guide lid 46 may also be formed such that at least
a portion of a bottom portion of the valve body 41 is exposed.
[0040]
30 The valve body 41 is located in the guide hole 42 and, in a case in which
pressure in the guide hole 42 is higher than pressure in the compression chamber 30,
slides and moves downward along the guide hole 42. The discharge outlet 45 is
thus closed. This state is referable to Fig. 2. When the valve body 41 closes the
discharge outlet 45, the side face of the valve body 41 is in contact with the
15
5 corresponding portion of the side face of the discharge outlet 45. For this reason, a
portion of the side face of the valve body 41 that faces the discharge outlet 45 is
formed such that the portion of the side face of the valve body 41 that faces the
discharge outlet 45 is not uneven to the side face of the discharge outlet 45. Also, in
a case in which pressure in the guide hole 42 is lower than pressure in the
10 compression chamber 30, the valve body 41 moves upward in the guide hole 42. As
illustrated in Fig. 3, the discharge outlet 45 is thus opened.
[0041]
Density of material of the valve body 41 is lower than density of steel. In
addition, at least a portion of the material of the valve body 41 may also be resin
15 material. In Embodiment 1, the resin material is polyetheretherketone (PEEK). In
addition, the resin material may also be polyamide imide (PAI) or aluminum.
[0042]
In addition, the surface of the valve body 41 is coated with metal. In
Embodiment 1, nickel phosphorus is coated. The thickness of coating is from 10
20 [μm] to 20 [μm].
[0043]
In a case in which the valve body 41 closes the discharge outlet 45, the spring
43 is smaller in length than its equilibrium length.
[0044]
25 In the valve body 41, a fitting portion is provided that fixes the spring 43. The
fitting portion fixes the outer diameter or the inner diameter of the end portion of the
spring 43.
[0045]
Between the valve body 41 and the valve-body seat portion 46c, a rubber
30 component may be provided. Such a provided rubber component cushions a shock
caused when the valve body 41 is seated on the valve-body seat portion 46c and the
rubber component also helps sealing. In addition, in the vicinity of the valve-body
seat portion 46c, an oil-supply groove may be provided through which oil is supplied.
Such a provided oil-supply groove provides oil film and thus secures sealing at a time
16
5 when the valve body 41 is seated on the valve-body seat portion 46c.
[0046]
The valve body 41 may also be in a state in which, when the discharge outlet
45 opens wide, the distal end of the valve body 41 protrudes slightly into the inside of
the discharge outlet 45 and partially covers the discharge outlet 45. The distal end
10 of the valve body 41 is thus prevented from entering the inside of the opening port in
the side face of the discharge outlet 45.
[0047]
Fig. 4 is a diagram that illustrates clearance Δc between the valve body 41 and
the guide hole 42 in the compressor 100 according to Embodiment 1.
15 [0048]
In Fig. 4, an inner diameter of the cylindrical portion 46b in a direction
orthogonal to a movement direction in which the valve body 41 moves along the
guide hole 42 is defined as ar. The outermost diameter of the valve body 41 in the
direction orthogonal to the movement direction in which the valve body 41 moves
20 along the guide hole 42 is defined as br. Clearance between the inner diameter ar of
the cylindrical portion 46b and the outermost diameter br of the valve body 41 is
defined as Δc.
[0049]
In this case, in the compressor 100 according to Embodiment 1, relationships
25 of Δc = ar − br (1) and 1/1000 ≤ Δc/br ≤ 1/100 (2) are satisfied.
[0050]
A linear expansion coefficient in relation to the temperature of the material of
the valve body 41 differs from a linear expansion coefficient in relation to the
temperature of the material of the valve-body seat portion 46c. Limits of a linear
30 expansion coefficient to the valve body 41 are limits in which an end face of the valve
body 41, at a time when the valve body 41 is seated, is not in the compression
chamber 30 at the maximum possible discharge temperature of high-pressure
refrigerant in an operation range in which the compressor 100 operates.
[0051]
17
5 The height of the valve body 41 is, for example, 15 [mm]. The height of the
guide hole 42, in which the valve body 41 moves, is 30 [mm]. For example, in a
case in which the outermost diameter br of the valve body 41 is 30 [mm], the
clearance Δc is from 30 [μm] to 300 [μm].
[0052]
10 As illustrated in Fig. 4, the valve-body seat portion 46c in the shaft bearing 14
has a taper shape. On the valve-body seat portion 46c, the valve body 41 is seated.
The shape of the distal end of the valve body 41 that faces the valve-body seat
portion 46c is a chamfered shape and is referred to as a taper shape 41_t. The
taper angle of the taper shape 41_t of the valve body 41 is equal to a taper angle of
15 the taper shape of the valve-body seat portion 46c.
[0053]
The valve body 41 has a hollow portion 41_b in the valve body 41. The shape
of the valve body 41 in a section viewed in the direction orthogonal to the movement
direction in which the valve body 41 moves may also be T-shaped.
20 [0054]
Fig. 5 is a side view that illustrates a valve body 41_1 that is T-shaped in the
compressor 100 according to Embodiment 1. Fig. 6 is a top view that illustrates the
valve body 41_1, which is T-shaped, in the compressor 100 according to Embodiment
1. Fig. 7 is a diagram that illustrates the discharge mechanism 40 to which the valve
25 body 41_1, which is T-shaped, is attached in the compressor 100 according to
Embodiment 1.
[0055]
As illustrated in Fig. 5 to Fig. 7, the valve body 41_1 is T-shaped in a section
viewed in the direction orthogonal to the movement direction in which the valve body
30 41 moves. That is, a section of a first portion 41_1_1 that is orthogonal to a
movement direction in which the valve body 41_1 moves is smaller than a section of
a second portion 41_1_2, which opens and closes the discharge outlet 45, that is
orthogonal to the movement direction.
[0056]
18
5 The first portion 41_1_1 of the valve body 41_1 is attached to the inside of the
spring 43. The first portion 41_1_1 of the valve body 41_1 is allowed to be attached
to the spring 43 in any method.
[0057]
[Operation of Compressor 100]
10 Electric power is supplied to the stator 22 in the motor unit 20 through the lead
wire. Electric current thus flows through the winding wire of the stator 22 and
magnetic flux is generated from the winding wire. The rotor 21 in the motor unit 20 is
rotated by action caused by magnetic flux generated from the winding wire and
magnetic flux generated from the permanent magnet in the rotor 21. By rotation of
15 the rotor 21, the main shaft 11, which is fixed to the rotor 21, is rotated. Along with
rotation of the main shaft 11, the rolling piston 16 in the compression mechanism unit
10 eccentrically rotates in the compression chamber 30 in the cylinder 13.
[0058]
A space between the cylinder 13 and the rolling piston 16 in the compression
20 chamber 30 is divided into two by an unillustrated vane. Along with rotation of the
main shaft 11, these two spaces changes their respective capacities. One space of
the two spaces gradually increases in capacity and low-pressure gas refrigerant is
sucked from the accumulator 300 into the one space. The other space of the two
spaces gradually reduces in capacity and gas refrigerant in the other space is
25 compressed in the compression chamber 30.
[0059]
The gas refrigerant compressed in the compression chamber 30 into a highpressure and high-temperature state pushes up the valve body 41 in the discharge
mechanism 40 and is discharged from the discharge outlet 45. The unillustrated
30 vane is pressed against the rolling piston 16 by high-pressure refrigerant emitted into
the airtight container 3. Along movement of the rolling piston 16, the vane radially
slides in the vane groove in a radial direction and serves such that the vane partitions
the space in the compression chamber 30 into a low-pressure space and a highpressure space. At this time, the discharge mechanism 40 is caused, by a pressure
19
5 difference between discharge pressure in the airtight container 3 and internal
pressure in the compression chamber 30, to open or close the discharge outlet 45
and discharge the compressed refrigerant. The discharge pressure in the airtight
container 3 varies with operational conditions of the refrigeration cycle. The
discharge mechanism 40 is thus caused to perform opening-closing operation by
10 relative height in pressure. The valve body 41, for example, opens when pressure is
higher than or equal to a specified pressure relative to discharge pressure in the
airtight container 3. Gas refrigerant discharged from the discharge outlet 45 is
discharged into a space in the airtight container 3 through the discharge outlet 45
located inside the discharge muffler 17. The discharged gas refrigerant passes
15 through a gap in the motor unit 20 and is discharged outside the airtight container 3
through the discharge pipe 2a, which is interlinked to a top portion of the airtight
container 3. The refrigerant discharged outside the airtight container 3 circulates in
the refrigeration cycle and turns back to the accumulator 300 again.
[0060]
20 [Operation of Discharge Mechanism 40]
Operation of the discharge mechanism 40 is described next. First, when the
internal pressure in the compression chamber 30 is lower than the internal pressure
in the guide hole 42 in the discharge mechanism 40, the valve body 41 receives a
load in a direction in which the valve body 41 closes the discharge outlet 45 from the
25 spring force of the spring 43 and the pressure in the guide hole 42. The end face of
the valve body 41 that faces toward the compression chamber 30, without protruding
from the corresponding end face of the compression chamber 30, closes the
discharge outlet 45 and receives the internal pressure in the compression chamber
30.
30 [0061]
Next, refrigerant is compressed in the compression chamber 30 and the end
face of the valve body 41 that faces toward the compression chamber 30 receives the
internal pressure. In a case in which the load from the internal pressure to the end
face of the valve body 41 that faces toward the compression chamber 30 is larger
20
5 than resultant force of the internal pressure in the guide hole 42 in the discharge
mechanism 40 and the spring force of the spring 43, the valve body 41, which closes
the discharge outlet 45, moves toward the spring 43 along the guide hole 42 as
illustrated in Fig. 3. The valve body 41 then opens the discharge outlet 45.
[0062]
10 When the discharge outlet 45 opens, a discharge course is formed through
which refrigerant is discharged. High-temperature and high-pressure gas refrigerant
discharged from the discharge outlet 45 is emitted into the airtight container 3.
Specifically, the refrigerant passes through a portion inside the guide hole 42 and
under the valve body 41, passes through the flange portion of the shaft bearing 14, as
15 indicated by an arrow a, passes through a hole provided to the side face of the guide
hole 42, as indicated by an arrow b, and flows into the discharge muffler 17. Highpressure refrigerant inside the discharge muffler 17 subsequently passes through a
gap defined between the shaft bearing 14 and the discharge muffler 17 and a hole
opened in the discharge muffler 17, as indicated by an arrow c, and is discharged into
20 the airtight container 3 of the compressor 100. When discharge of the refrigerant is
completed, the valve body 41 moves to the discharge outlet 45 by the spring force of
the spring 43 and starts closing the discharge outlet 45. The internal pressure in the
compression chamber 30 is then lower than the pressure in the airtight container 3.
Next, as illustrated in Fig. 2, the distal end of the valve body 41 that faces toward the
25 compression chamber 30 is pressed against the valve-body seat portion 46c, which is
located at the distal end of the discharge outlet 45, by a pressure difference between
pressure in the guide hole 42 and pressure in the compression chamber 30 and the
discharge outlet 45 is fully closed.
[0063]
30 A threshold value for the internal pressure in the compression chamber 30 at
which discharge operation of refrigerant is performed may be an absolute value.
The spring 43 does not have to operate in the guide hole 42. To reduce pressure
loss of refrigerant that passes through the communication hole 44, another spring 43
may also be provided to a portion other than the guide hole 42 such that the guide
21
5 hole 42 is increased in capacity.
[0064]
In addition, in the discharge mechanism 40 according to Embodiment 1, the
guide lid 46 may also not be provided with the communication hole 44.
[0065]
10 In addition, the discharge mechanism 40 for the cylinder 13 at which the
second suction pipe 31b is located may be located at a shaft bearing 14a, which is
lower than the shaft bearing 14.
[0066]
Fig. 8 is a diagram that illustrates a case in which a first discharge mechanism
15 40_1 and a second discharge mechanism 40_2 are provided to the compressor 100
according to Embodiment 1. As illustrated in Fig. 8, the first discharge mechanism
40_1 is attached to the shaft bearing 14, which is located higher than the cylinder 13,
and the second discharge mechanism 40_2 is attached to the shaft bearing 14a,
which is lower than the cylinder 13. The configuration of the first discharge
20 mechanism 40_1 and the configuration of the second discharge mechanism 40_2
each are substantially similar to the configuration of the discharge mechanism 40.
[0067]
The first discharge mechanism 40_1 and the second discharge mechanism
40_2 differ from each other in that the mass of the valve body 41 in the second
25 discharge mechanism 40_2 is smaller than the mass of the valve body 41 in the first
discharge mechanism 40_1. The spring constant of the spring 43 in the second
discharge mechanism 40_2 is larger than the spring constant of the spring 43 in the
first discharge mechanism 40_1. The equilibrium length of the spring 43 in the
second discharge mechanism 40_2 is smaller than the equilibrium length of the
30 spring 43 in the first discharge mechanism 40_1.
[0068]
In a case in which a plurality of compression chambers 30 and a plurality of
discharge mechanisms 40 are provided, the reciprocating movement of each of the
valve bodies 41 is affected by the gravity. For this reason, the masses of the
22
5 respective valve bodies 41 are designed to differ from each other such that the time
periods from the opening to the closure of respective discharge outlets 45 are the
same as each other. In this case, the mass of the valve body 41 that moves upward
to close its corresponding discharge outlet 45 is smaller than the mass of the valve
body 41 that moves downward to close its corresponding discharge outlet 45.
10 [0069]
[Advantageous Effects]
With the compressor 100 according to Embodiment 1, relationships of Δc = ar −
br and 1/1000 ≤ Δc/br ≤ 1/100 are satisfied, sealing is thus tighter between a space
around the valve body 41 in which the spring 43 is located and a space around the
15 valve body 41 and in the vicinity of the discharge outlet 45. As a result, by effective
use of differential pressure between pressure in the space around the valve body 41
in which the spring 43 is located and pressure in the space around the valve body 41
and in the vicinity of the discharge outlet 45, a movement speed at which the valve
body 41 moves is increased. The compressor 100 is therefore provided that has
20 improved compression efficiency.
[0070]
This differential pressure is used not only when the discharge outlet 45 is
closed by the valve body 41 but also when the valve body 41 rises such that the
discharge outlet 45 is opened. The movement speed of the valve body 41 is thus
25 increased to be high. In addition, in comparison with a case in which a reed valve is
used, the compressor 100 according to Embodiment 1 ensures a large area of a flow
passage through which refrigerant is discharged, has reduced pressure loss when
refrigerant is discharged, and has improved efficiency of the compressor.
[0071]
30 In addition, resin material, which is lightweight, is used for the valve body 41,
frictional force is thus reduced between the valve body 41 and the side face of the
cylindrical portion 46b when the valve body 41 opens and closes the discharge outlet
45. In the compressor 100 according to Embodiment 1, the valve body 41 is
therefore prevented from slowly opening and slowly closing and over-compression
23
5 loss and suction over-heat loss are thus reduced. In addition, a shock load is also
reduced between the valve body 41 and the end portion of the guide hole 42 when
the valve body 41 closes the discharge outlet 45. The compressor 100 therefore has
increased reliability.
[0072]
10 The valve body 41 is coated with metal and the valve body 41 thus has
increased reliability in its reciprocating movement.
[0073]
In a case in which the valve body 41 closes the discharge outlet 45, the spring
43 is smaller in length than its equilibrium length. Even in a state in which the valve
15 body 41 is seated and in a state in which differential pressure of refrigerant before
discharge and after discharge is small, the valve body 41 is seated and thus
sufficiently seals the shaft bearing 14 and the compressor 100 is thus operational.
The state in which differential pressure of refrigerant before discharge and after
discharge is small, described above, is based on an operation range in which a
20 typical compressor 100 operates. For example, when R410A is in use as refrigerant,
the differential pressure of refrigerant is as small in extent as 0.5 MPa between 2 MPa
of discharged refrigerant and 1.5 MPa of refrigerant to be sucked.
[0074]
In addition, in the compressor 100 according to Embodiment 1, in a case in
25 which pressure in the guide hole 42 in the guide lid 46 is higher than pressure in the
compression chamber 30, the valve body 41 moves in the guide hole 42 and the
discharge outlet 45 is closed. Refrigerant discharged from the discharge outlet 45 is
discharged into the airtight container 3. The communication hole 44 communicates
with the space in the airtight container 3 and discharge refrigerant, which is higher in
30 pressure than refrigerant that remains in the guide hole 42, thus compresses a space
in the guide hole 42 and above the valve body 41. Resultant damper effect thus
prevents the valve body 41 from slowly opening and from slowly closing the discharge
outlet 45.
[0075]
24
5 In addition, in the compressor 100 according to Embodiment 1, the
communication hole 44 is located in the guide lid 46. The diameter of the
communication hole 44 is smaller than the inner diameter of the guide lid 46. When
the valve body 41 rises, a small amount of refrigerant in a space between the valve
body 41 and the closure portion 46a does not therefore passes through the
10 communication hole 44. Such remaining refrigerant is compressed and the valve
body 41 is pushed back. At this time, the pressure of the refrigerant, which remains
in the space between the valve body 41 and the closure portion 46a, is further higher
than the pressure of high-pressure refrigerant that has been compressed and
discharged into the airtight container 3. This damper effect causes the valve body
15 41 to start descending immediately after the valve body 41 finishes rising. The valve
body 41 thus achieves closure and is seated on the valve-body seat portion 46c
located in the shaft bearing 14 not later than a desired seating timing.
[0076]
In addition, in the compressor 100 according to Embodiment 1, the horizontal
20 outer diameter of the communication hole 44 is specified to be smaller than the
horizontal outer diameter of the valve body 41 and the valve body 41 is thus further
prevented from causing closure at reduced speed.
[0077]
In addition, in the compressor 100 according to Embodiment 1, the one end of
25 the guide hole 42 that faces toward the compression chamber 30 is formed such that
the one end coincides with the corresponding end face of the compression chamber
30 and fits on the inside wall of the cylinder 13. Refrigerant thus flows an increased
area of a flow passage with reduced discharge pressure loss.
[0078]
30 In addition, in the compressor 100 according to Embodiment 1, the discharge
course is configured such that the compression chamber 30, the valve body 41, and
the discharge outlet 45 are sequentially arranged. Also, immediately after the
compression chamber 30, the valve body 41 closes the discharge outlet 45. Dead
volume in the compressor 100 is thus reduced. Reduction in efficiency of the
25
5 compressor 100 caused by re-expansion of refrigerant is thus prevented.
[0079]
In addition, in the compressor 100 according to Embodiment 1, the end face of
the compression chamber 30 and the end face of the valve body 41 that faces toward
the compression chamber 30 coincide with each other at the same plane. The dead
10 volume in the compressor 100 is thus possibly minimized and the valve body 41
protrudes inside the compression chamber 30 and the valve body 41 is thus
prevented from colliding with the rolling piston 16.
[0080]
In addition, in the compressor 100 according to Embodiment 1, the cylindrical
15 portion 46b of the guide lid 46 is formed as a part separate from the shaft bearing 14,
the structure of the shaft bearing 14 is thus simplified and the compressor 100 is
provided at low cost.
[0081]
In addition, in the compressor 100 according to Embodiment 1, in a case in
20 which the cylindrical portion 46b of the guide lid 46 and the shaft bearing 14 are
integrally formed with each other, the core of the valve body 41 and the core of the
valve-body seat portion 46c are prevented from being off-centered and the
compressor 100 with high reliability is thus provided.
[0082]
25 In addition, in the compressor 100 according to Embodiment 1, the horizontal
outer diameter of the communication hole 44 is smaller than the horizontal outer
diameter of the valve body 41. The communication hole 44 thus serves as a
squeeze outlet and an advantageous effect is produced in which damper effect in the
communication hole 44 to be reduced is made not to be reduced more than or equal
30 to a designed and desired extent. Also, when the discharge outlet 45 is to be closed,
another advantageous effect is produced in helping immediate closure by the valve
body 41.
[0083]
Embodiment 2
26
5 Fig. 9 is a refrigerant circuit diagram that schematically illustrates a
configuration of a refrigerant circuit in a refrigeration cycle apparatus 200 according to
Embodiment 2. With reference to Fig. 9, the configuration and operation of the
refrigeration cycle apparatus 200 is described below. The refrigeration cycle
apparatus 200 according to Embodiment 2 is a refrigerant circuit to which any of the
10 compressors 100 according to Embodiment 1 is provided as one component. Fig. 9
illustrates, for descriptive purposes, a case in which the compressor 100 according to
Embodiment 1 is provided.
[0084]

15 The refrigeration cycle apparatus 200 has the compressor 100, a flow-passage
selector 151, a first heat exchanger 152, an expansion device 153, and a second heat
exchanger 154. The compressor 100, the first heat exchanger 152, the expansion
device 153, and the second heat exchanger 154 are connected to each other by a
high-pressure pipe 155a and the low-pressure pipe 155b and thus form the refrigerant
20 circuit. Also, to an upper stream of the compressor 100, the accumulator 300 is
provided.
[0085]
The compressor 100 is configured to compress sucked refrigerant into a hightemperature and high-pressure state. Refrigerant compressed in the compressor
25 100 is discharged from the compressor 100 and sent to the first heat exchanger 152
or the second heat exchanger 154.
[0086]
The flow-passage selector 151 is configured to switch respective refrigerant
flows for cooling operation and heating operation. In other words, the flow-passage
30 selector 151 is switched such that the compressor 100 and the second heat
exchanger 154 are connected to each other for heating operation and such that the
compressor 100 and the first heat exchanger 152 are connected to each other for
cooling operation. The flow-passage selector 151 is preferably, for example, a fourway valve. Combination of two-way valves and three-way valves, however, may
27
5 also be used as the flow-passage selector 151.
[0087]
The first heat exchanger 152 is configured to operate as an evaporator during
heating operation and operate as a condenser during cooling operation. In other
words, in a case in which the first heat exchanger 152 operates as an evaporator, the
10 first heat exchanger 152 allows low-temperature and low-pressure refrigerant that
flows out from the expansion device 153 and air supplied by, for example, an
unillustrated air-sending device to exchange heat with each other and lowtemperature and low-pressure liquid refrigerant or two-phase gas-liquid refrigerant
thus evaporates. On the other hand, in a case in which the first heat exchanger 152
15 operates as a condenser, the first heat exchanger 152 allows high-temperature and
high-pressure refrigerant discharged from the compressor 100 and air supplied by, for
example, an unillustrated air-sending device to exchange heat with each other and
high-temperature and high-pressure gas refrigerant thus condenses. The first heat
exchanger 152 may also be a refrigerant-water heat exchanger. In this case, the
20 first heat exchanger 152 allows refrigerant and a heat medium, such as water, to
exchange heat with each other.
[0088]
The expansion device 153 is configured to expand and decompress refrigerant
that flows out from the first heat exchanger 152 or the second heat exchanger 154.
25 The expansion device 153 is preferably, for example, a component such as an electric
expansion valve that is configured to adjust a flow rate of refrigerant. To the
expansion device 153, not only the electric expansion valve but also a mechanical
expansion valve in which a diaphragm is use as a pressure receiver, a capillary tube,
or other component is applicable.
30 [0089]
The second heat exchanger 154 is configured to operate as a condenser
during heating operation and operate as an evaporator during cooling operation. In
other words, in a case in which the second heat exchanger 154 operates as a
condenser, the second heat exchanger 154 allows high-temperature and high-
28
5 pressure refrigerant discharged from the compressor 100 and air supplied by, for
example, an unillustrated air-sending device to exchange heat with each other and
high-temperature and high-pressure gas refrigerant thus condenses. On the other
hand, in a case in which the second heat exchanger 154 operates as an evaporator,
the second heat exchanger 154 allows low-temperature and low-pressure refrigerant
10 that flows out from the expansion device 153 and air supplied by, for example, an
unillustrated air-sending device to exchange heat with each other and lowtemperature and low-pressure liquid refrigerant or two-phase gas-liquid refrigerant
thus evaporates. The second heat exchanger 154 may also be a refrigerant-water
heat exchanger. In this case, the second heat exchanger 154 allows refrigerant and
15 a heat medium, such as water, to exchange heat with each other.
[0090]
Also, to the refrigeration cycle apparatus 200, a controller 160 is provided,
which is configured to exercise integrated control of the entirety of the refrigeration
cycle apparatus 200. Specifically, the controller 160 controls a driving frequency of
20 the compressor 100 in accordance with required cooling capacity or required heating
capacity. The controller 160 also controls an opening degree of the expansion
device 153 depending on an operational state and a selected mode. In addition, the
controller 160 controls the flow-passage selector 151 in accordance with a selected
mode.
25 [0091]
The controller 160 controls an actuator, such as the compressor 100, the
expansion device 153, and the flow-passage selector 151, in accordance with an
operational instruction from a user and by use of pieces of information sent from
unillustrated temperature sensors and unillustrated pressure sensors.
30 [0092]
The controller 160 may be formed by a piece of hardware, such as a circuit
device, that is configured to perform functions of the controller 160 and may also be
formed by an arithmetic unit, such as a microcomputer and a CPU, and software run
on the arithmetic unit.
29
5 [0093]
The controller 160 is formed by a dedicated piece of hardware or is formed by
a central processing unit, which is also referred to as a CPU, a central processor, a
processing unit, an arithmetic unit, a microprocessor, a microcomputer, and a
processor, and that is configured to execute a program stored in a memory. In a
10 case in which the controller 160 is a dedicated piece of hardware, the controller 160
corresponds to, for example, a single circuit, a composite circuit, an application
specific integrated circuit (ASIC), a field programmable gate array (FPGA), or
combination of these components above listed. Functions performed by the
controller 160 may be performed by respective pieces of hardware. The functions
15 may also be performed by a single piece of hardware. In a case in which the
controller 160 is formed by a CPU, functions performed by the controller 160 are
performed by software, firmware, or combination of software and firmware. Software
and firmware are described as a program and stored in a memory. The CPU reads
out and executes the program stored in the memory and performs the functions of the
20 controller 160. The memory here is, for example, a non-volatile or volatile
semiconductor memory such as RAM, a ROM, a flash memory, an EPROM, and an
EEPROM. One of functions of the controller 160 may be performed by a dedicated
piece of hardware and another may be performed by software or firmware.
[0094]
25
Operation of the refrigeration cycle apparatus 200 is described below together with
refrigerant flow. With reference to, as an example, a case in which heat-exchange
fluid at the first heat exchanger 152 and the second heat exchanger 154 is air,
operation of the refrigeration cycle apparatus 200 during cooling operation is
30 described below. In Fig. 9, dotted-line arrows indicate refrigerant flow during cooling
operation, and solid-line arrows indicate refrigerant flow during heating operation.
[0095]
The compressor 100 is driven and refrigerant in a high-temperature and highpressure gas state is thus discharged from the compressor 100. The high-
30
5 temperature and high-pressure gas refrigerant, which is single-phase, discharged
from the compressor 100 flows into the first heat exchanger 152. In the first heat
exchanger 152, the high-temperature and high-pressure gas refrigerant that flows in
and air supplied by an unillustrated air-sending device exchange heat with each other
and the high-temperature and high-pressure gas refrigerant thus condenses into high10 pressure liquid refrigerant, which is single-phase.
[0096]
The high-pressure liquid refrigerant sent from the first heat exchanger 152
turns into, by the expansion device 153, refrigerant in a two-phase state of lowpressure gas refrigerant and liquid refrigerant. The refrigerant in the two-phase state
15 flows into the second heat exchanger 154. In the second heat exchanger 154, the
refrigerant in the two-phase state that flows in and air supplied by an unillustrated airsending device exchange heat with each other and the liquid refrigerant included in
the refrigerant in the two-phase state thus evaporates and the refrigerant in the twophase state turns into low-pressure gas refrigerant, which is single-phase. The low20 pressure gas refrigerant sent from the second heat exchanger 154 flows into the
compressor 100 through the accumulator 300 and is compressed into hightemperature and high-pressure gas refrigerant and is discharged from the
compressor 100 again. Subsequently, this cycle is repeated.
[0097]
25 With the refrigeration cycle apparatus 200 according to Embodiment 2, the
refrigeration cycle apparatus 200 in which the compressor 100 with high compression
efficiency is used is therefore provided.
[0098]
Operation of the refrigeration cycle apparatus 200 during heating operation is
30 performed by causing the flow-passage selector 151 to switch the refrigerant flow to
flows indicated by the solid-line arrows illustrated in Fig. 9.
[0099]
Without the flow-passage selector 151 provided to a discharge portion of the
compressor 100 being provided, the refrigerant flow may also be in a constant
31
5 direction.
[0100]
In addition, application examples of the refrigeration cycle apparatus 200
include an air-conditioning apparatus, a water heater, a freezer, and an airconditioning and water-heating composite device.
10 [0101]
Embodiment 3
In Embodiment 3, types of refrigerants used in the refrigeration cycle apparatus
200 according to Embodiment 2 are described.
[0102]
15 A refrigerant used in the refrigeration cycle apparatus 200 according to
Embodiment 3 is lower than an R410A refrigerant in gas density. Such refrigerants
include, for example, R134a, R1234yf, R513A, R463A, R290, R454C, R454A, R404A,
R448A, R449A, R454B, R452B, and R466A.
[0103]
20 Fig. 10 is a chart that illustrates gas density in refrigerant sucked in the
compressor and gas density in refrigerant discharged from the compressor 100 under
rated conditions of compressor 100 operation in a typical refrigeration cycle stipulated
in ASHRAE.
[0104]
25 The ASHRAE here is an acronym of American Society of Heating, Refrigerating
and Air-Conditioning Engineers. The rated conditions of compressor operation is
also widely referred to as ASRAE-T conditions. In the conditions, condensing
temperature is defined to 54.4 degrees C, an evaporating temperature is defined to
7.2 degrees C, a degree of subcooling is defined to 8.3 degrees C, and a degree of
30 superheat is defined to 27.8 degrees C.
[0105]
Fig. 10 lists refrigerants of R134a, R1234yf, R513A, R463A, R290, R454C,
R454A, R404A, R448A, R449A, R454B, R452B, and R466A. These refrigerants
each are, as illustrated in Fig. 10, lower than R410A in gas density both in a case in
32
5 which refrigerant is sucked into the compressor 100 and in a case in which refrigerant
is discharged from the compressor 100.
[0106]
Fluid such as refrigerant gas typically increases in pressure loss in proportion
to flow velocity of the fluid. As long as refrigerant is to be circulated with the same
10 weight, flow velocity of gas has to be increased when density reduces. In other
words, refrigerant gas with low density increases to be higher in pressure loss than
refrigerant gas with high density. Such pressure loss is caused at various portions in
the refrigeration cycle. In particular, its effect is remarkable at a discharge valve of
compression and other portion at which a flow passage is narrow and flow velocity of
15 fluid is high.
[0107]
Pressure loss in a flow passage causes energy loss and thus reduces
efficiency in the entirety of the refrigeration cycle. As a discharge valve in a rotary
compressor 100, a reed valve is typically used. Fig. 11 is a diagram that illustrates
20 an example of a reed valve 401 in a compressor 100. As illustrated in Fig. 11, one
end of a reed valve 401 and one end of a restrictor plate 402 are fixed to the vicinity
of a discharge hole 405 provided in an end face of the shaft bearing 14 by a fastener
rivet 403. The restrictor plate 402 restricts movement of the reed valve 401. The
reed valve 401 is seated on a seat portion 404 and closes the discharge hole 405.
25 The reed valve 401 is lifted up by pressure increase in the compression chamber 30.
The reed valve 401 is, as described above, structured such that the reed valve 401 is
lifted up from its one end, a lift distance R between the end face of the shaft bearing
14 and a portion close to a portion at which the reed valve 401 is fixed is shorten, and
the entire area of a flow passage is reduced.
30 [0108]
Fig. 12 is a diagram that illustrates the lift distance R of the valve body 41 in the
compressor 100 used in the refrigeration cycle apparatus 200 according to
Embodiment 3. As illustrated in Fig. 12, the valve body 41 in the discharge
mechanism 40 in the compressor 100 moves in the guide hole 42 by the spring 43 in
33
5 the vertical direction. The lift distance R is therefore uniform for the entirety of the
valve body 41 and the entire area of a refrigerant flow passage is increased and
larger than a case of the reed valve 401.
[0109]
The area of the refrigerant flow passage is increased and flow velocity at the
10 discharge outlet 45 is thus reduced and pressure loss at the discharge outlet 45 is
reduced. Such an effect is remarkable with refrigerant that has low gas density.
[0110]
The refrigeration cycle apparatus 200 according to Embodiment 3 applies a
refrigerant that is lower in gas density than R410A, which is widely used in the world
15 at present, to the refrigeration cycle apparatus 200 according to Embodiment 2. The
refrigeration cycle apparatus 200 according to Embodiment 3 is therefore configured
to reduce pressure loss and obtains a refrigeration cycle with high efficiency. In
particular, in a case in which R290, which is remarkably higher than each of the other
refrigerants in suction gas density and discharge gas density, is used as refrigerant,
20 the refrigeration cycle apparatus 200 is configured to reduce pressure loss and
obtains a refrigeration cycle with high efficiency.
[0111]
The embodiments are presented above as examples and not intended to limit
the scope of claims. The embodiments may also be achieved by other various forms
25 and may also be partially omitted, replaced, or changed in various forms without
departing from the gist of the embodiments. These embodiments and their
modifications are included in the scope of the embodiments and the gist of
embodiments.
Reference Signs List
30 [0112]
1: lower container, 2: upper container, 2a: discharge pipe, 3: airtight container,
10: compression mechanism unit, 11: main shaft, 11a: main shaft portion, 12:
eccentric shaft portion, 13: cylinder, 14, 14a: shaft bearing, 15: partition plate, 16:
rolling piston, 17: discharge muffler, 20: motor unit, 21: rotor, 22: stator, 30:
34
5 compression chamber, 31a: first suction pipe, 31b: second suction pipe, 40: discharge
mechanism, 40_1: first discharge mechanism, 40_2: second discharge mechanism,
41, 41_1: valve body, 41_1_1: first portion, 41_1_2: second portion, 41_t: taper shape,
41_b: hollow portion, 42: guide hole, 43: spring, 44, 44a, 44b, 44c: communication
hole, 45: discharge outlet, 46: guide lid, 46a: closure portion, 46b: cylindrical portion,
10 46c: valve-body seat portion, 50: suction inlet, 60: suction muffler, 100: compressor,
141: screw hole, 151: flow-passage selector, 152: first heat exchanger, 153:
expansion device, 154: second heat exchanger, 155a: high-pressure pipe, 155b: lowpressure pipe, 160: controller, 200: refrigeration cycle apparatus, 300: accumulator,
401: reed valve, 402: restrictor plate, 403: fastener rivet, 404: seat portion, 405:
15 discharge hole, R: lift distance, ar: inner diameter of cylindrical portion, br: outermost
diameter of valve body, Δc: clearance

5 WE CLAIM:
[Claim 1]
A compressor comprising:
an airtight container;
a cylinder provided in the airtight container and in which a compression
10 chamber is provided in which refrigerant is compressed;
a shaft bearing provided in the airtight container and to which a discharge
outlet is provided through which refrigerant compressed in the compression chamber
is discharged; and
a discharge mechanism that has a guide lid that is provided to the shaft bearing
15 and has a cylindrical portion in which a guide hole is opened, a valve body provided in
the guide hole, and a connection component that is provided in the guide hole and by
which the guide lid and the valve body are connected to each other, the discharge
mechanism being configured to open and close the discharge outlet when the valve
body moves in the guide hole,
20 when an inner diameter of the cylindrical portion in a direction orthogonal to a
movement direction in which the valve body moves along the guide hole is defined as
ar,
an outermost diameter of the valve body in the direction orthogonal to the
movement direction in which the valve body moves along the guide hole is defined as
25 br, and
clearance between the inner diameter ar of the cylindrical portion and the
outermost diameter br of the valve body is defined as Δc,
relationships described below being satisfied:
Δc = ar − br, and
30 1/1000 ≤ Δc/br ≤ 1/100.
[Claim 2]
The compressor of claim 1, wherein density of material of the valve body is
lower than density of steel.
36
5 [Claim 3]
The compressor of claim 1 or 2, wherein at least a portion of material of the
valve body comprises resin material.
[Claim 4]
The compressor of any one of claims 1 to 3, wherein a surface of the valve
10 body is coated with metal.
[Claim 5]
The compressor of any one of claims 1 to 4, wherein the valve body is Tshaped in a section viewed in the direction orthogonal to the movement direction in
which the valve body moves.
15 [Claim 6]
The compressor of any one of claims 1 to 5, wherein the valve body has a
hollow portion in the valve body.
[Claim 7]
The compressor of any one of claims 1 to 6, wherein, in a case in which the
20 valve body closes the discharge outlet, the connection component is smaller in length
than an equilibrium length of the connection component.
[Claim 8]
The compressor of any one of claims 1 to 7, wherein
the shaft bearing has a valve-body seat portion that has a taper shape and on
25 which the valve body is seated,
a shape of a distal end of the valve body that faces the valve-body seat portion
is a taper shape, and
a taper angle of the taper shape of the valve body is equal to a taper angle of
the taper shape of the valve-body seat portion.
30 [Claim 9]
The compressor of claim 8, wherein a linear expansion coefficient in relation to
a temperature of material of the valve body differs from a linear expansion coefficient
in relation to a temperature of material of the valve-body seat portion.
37
5 [Claim 10]
The compressor of any one of claims 1 to 9, wherein
the shaft bearing comprises an upper shaft bearing and a lower shaft bearing,
the discharge mechanism comprises a first discharge mechanism provided in
the upper shaft bearing and a second discharge mechanism provided in the lower
10 shaft bearing, and
the valve body in the second discharge mechanism is more lightweight than the
valve body in the first discharge mechanism.
[Claim 11]
The compressor of claim 10, wherein the connection component comprises
15 springs, and
a spring constant of one of the springs in the second discharge mechanism is
larger than a spring constant of an other of the springs in the first discharge
mechanism.
[Claim 12]
20 The compressor of claim 10 or 11, wherein an equilibrium length of one of
springs in the second discharge mechanism is smaller than an equilibrium length of
an other of the springs in the first discharge mechanism.
[Claim 13]
A refrigeration cycle apparatus comprising:
25 the compressor of any one of claims 1 to 12;
a first heat exchanger;
an expansion device; and
a second heat exchanger, wherein,
through the compressor, the first heat exchanger, the expansion device, and
30 the second heat exchanger, refrigerant circulates.
[Claim 14]
The refrigeration cycle apparatus of claim 13, wherein the refrigerant is a
refrigerant that is lower than R410A in gas density.

[Claim 15]
The refrigeration cycle apparatus of claim 14, wherein the refrigerant is R290.