EP3783225A1

EP3783225A1 - Hermetic compressor and refrigeration cycle apparatus

Info

Publication number: EP3783225A1
Application number: EP19789323.3A
Authority: EP
Inventors: Takuya Hirayama; Shigeki Kimura
Original assignee: Toshiba Carrier Corp
Current assignee: Toshiba Carrier Corp
Priority date: 2018-04-20
Filing date: 2019-04-02
Publication date: 2021-02-24
Anticipated expiration: 2039-04-02
Also published as: CN112055785B; WO2019202976A1; JP2019190302A; EP3783225B1; JP7066495B2; EP3783225A4; CN112055785A

Abstract

To provide a compressor with high compression efficiency provided by increasing the design freedom with respect to the position for connecting an introduction path and an injection path of an injection flow path to improve manufacturability, and by reducing the back flow of refrigerant from a check valve of the injection flow path. An injection flow path (40) includes an injection path (41) opened to a cylinder chamber (19), a communication path (42) connected to the injection path (41), an introduction path (49) having one end side opened to the communication path (42) from an axial direction and the other end (54) to which an injection introduction pipe (70) connected to the outside of a sealed case is connected, and a check valve device (44) that opens and closes an opening portion (53) of the introduction path (49) on the communication path (42) side and blocks a flow of refrigerant from the cylinder chamber (19) to the introduction path (49). The check valve device (44) includes a reed valve (60), a valve retainer (64) that regulates the opening degree of the reed valve (60), and a fixing member (65) that fixes the reed valve (60) and the valve retainer (64).

Description

TECHNICAL FIELD

Embodiments of the present invention relate to a hermetic compressor including an injection flow path, and to a refrigeration cycle apparatus.

BACKGROUND

Conventionally, there may be a case where a hermetic compressor has, for the purpose of cooling, an injection flow path that introduces liquid refrigerant at an intermediate pressure in a refrigeration cycle into the cylinder chamber of a compression mechanism. Such liquid refrigerant at the intermediate pressure evaporates in the cylinder chamber, thus decreasing the temperature of a discharge refrigerant that is discharged from the cylinder chamber.
To reduce compression loss caused by the back flow of a compressed refrigerant from the cylinder chamber to the injection flow path, such a hermetic compressor may include a check valve in the middle of the injection flow path.

PRIOR ART DOCUMENT

PATENT DOCUMENT

Patent Document 1: JP S62-173585 U
Patent Document 2: JP 5760836 B2

SUMMARY

PROBLEMS TO BE SOLVED BY INVENTION

The injection flow path of a compressor disclosed in Patent Document 1 and Patent Document 2 includes an introduction path that introduces liquid refrigerant to a compression mechanism, and an injection path that allows the liquid refrigerant, which is introduced through the introduction path, to be injected into a cylinder chamber. The introduction path extends in the radial direction. The injection path extends in the axial direction of the rotary shaft of the compressor. In this case, the introduction path and the injection path are made to communicate with each other and hence, restrictions are imposed on the design freedom with respect to the position for forming the injection flow path.
Further, the injection flow path of the compressor disclosed in Patent Document 1 includes a communicating pipe that is connected from a gas injection pipe, and a gas injection flow path that allows refrigerant to be injected into the cylinder chamber. A check valve is provided to extend in a direction orthogonal to a flow direction of the communicating pipe. Thus, a slight gap is formed between the communicating pipe and the check valve. This gap causes back flow of compressed refrigerant, so that compression loss occurs.
In the injection flow path of the compressor disclosed in Patent Document 2, it is necessary to insert a slide valve into an intermediate portion of an injection introduction path with high accuracy. For this reason, the injection flow path of the compressor disclosed in Patent Document 2 has extremely low manufacturability.
It is an object of the present invention to provide a compressor with high compression efficiency provided by increasing the design freedom with respect to the position for connecting the introduction path and the injection path of the injection flow path to improve manufacturability, and by reducing the back flow of refrigerant from the check valve of the injection flow path.

MEANS FOR SOLVING PROBLEM

To achieve the above-mentioned object, a hermetic compressor according to this embodiment includes: a sealed case; and a compression mechanism accommodated in the sealed case. The compression mechanism includes a cylinder having a cylinder chamber, a closing member fixed to one end surface of the cylinder to close the cylinder chamber, an end plate overlapped with the closing member, an injection flow path through which refrigerant is supplied into the cylinder chamber, a roller configured to compress the refrigerant that flows into the cylinder chamber, and a check valve device provided in the injection flow path. The injection flow path includes an injection path formed in the closing member, and having one end opened to the cylinder chamber, and another end opened toward the end plate, a communication path provided between the closing member and the end plate, and connected to the injection path, and an introduction path provided in either one of the closing member or the end plate, and having one end and another end, the one end being opened in a direction along which the closing member and the end plate overlap with each other and being connected to the communication path, and the another end being connected to an injection introduction pipe that communicates with an outside of the sealed case. The check valve device includes a reed valve that opens and closes the introduction path, a valve retainer configured to regulate an opening degree of the reed valve, and a fixing member that fixes the reed valve and the valve retainer. The reed valve and the valve retainer are fixed to the closing member or the end plate in which the introduction path is provided.
In the hermetic compressor according to the embodiment of the present invention, it may be desired that a valve seat surface of the reed valve and a joint surface between the closing member and the end plate be on a same plane.
It may be further desired that a discharge hole that allows the refrigerant compressed in the cylinder chamber to be discharged into a sealed case, and a discharge valve that opens and closes the discharge hole, and the check valve device opens a communication-path-side opening portion of the introduction path at a differential pressure higher than a differential pressure at which the discharge valve opens the discharge hole.
It may be desired that the reed valve includes a fixed support portion fixed using the fixing member, an opening and closing portion that opens and closes the communication-path-side opening portion of the introduction path, and a reed portion coupling the fixed support portion and the opening and closing portion to each other, and the fixed support portion disposed at a position that is outward of the cylinder chamber in a radial direction of a rotary shaft that connects the compression mechanism and an electric motor that drives the compression mechanism, and has no overlap with the injection flow path as viewed from an axial direction of the rotary shaft.
It may be desired that the check valve device is provided in the communication path, and a volume of the check valve device is larger than a space capacity that is obtained by subtracting the volume of the check valve device from a volume of the communication path.
It may be desired that at least a portion of the communication path of the hermetic compressor according to the embodiment of the present invention to be disposed at a position lower than a communication-path-side opening portion of the injection path.
It may be desired that the compression mechanism of the hermetic compressor according to the embodiment of the present invention includes a plurality of the cylinders, and the injection flow path is provided between the plurality of the cylinders.
It may be further desired that two partition plates that closes the cylinder chamber are arranged between the plurality of the cylinders, and are arranged in an axial direction of a rotary shaft coupling the compression mechanism and an electric motor that drives the compression mechanism to each other, and one of the two partition plates is the closing member, and another of the two partition plates is the end plate.
It may be desired that the injection path is opened to the cylinder chamber of one of the plurality of the cylinders, and the injection path includes an auxiliary injection path that is provided in the end plate, and has one end opened to the cylinder chamber of another of the plurality of the cylinders and another end opened to the communication path.
To achieve the above-mentioned object, a refrigeration cycle apparatus according to the embodiment of the present invention includes: the hermetic compressor; a radiator connected to the hermetic compressor; an expansion device connected to the radiator; and a heat sink connected between the expansion device and the hermetic compressor.

ADVANTAGE OF THE INVENTION

According to the present invention, it is possible to provide the compressor with high compression efficiency provided by increasing the design freedom with respect to the position for connecting the introduction path and the injection path of the injection flow path to improve manufacturability, and by reducing the back flow of refrigerant from the check valve of the injection flow path.

BRIEF DESCRIPTION OF DRAWINGS

Fig. 1 is a view showing the internal structure of a hermetic compressor according to a first embodiment, and is also a configuration diagram of a refrigeration cycle of a refrigeration cycle apparatus.
Fig. 2 is a plan view of a compression mechanism according to the first embodiment.
Fig. 3 is a plan view of a main bearing according to the first embodiment.
Fig. 4 is a view showing the structure of an injection flow path with a check valve device according to the first embodiment being in a closed state.
Fig. 5 is a view showing the structure of an injection circuit with the check valve device according to the first embodiment being in an open state.
Fig. 6 is a view showing the positional relationship between the injection flow path and the check valve device according to the first embodiment.
Fig. 7 is a view showing the internal structure of a hermetic compressor according to a second embodiment, and is also a configuration diagram of a refrigeration cycle of a refrigeration cycle apparatus.
Fig. 8 is a view showing the structure of an injection circuit with a check valve device according to the second embodiment being in an open state.

DETAILED DESCRIPTION

Hereinafter, embodiments for carrying out the invention will be described with reference to drawings. In a plurality of drawings, identical or corresponding components are given the same reference numerals.

(First embodiment)

A first embodiment of a hermetic compressor will be described by referring to Fig. 1 to Fig. 6.
Fig. 1 is a view showing the internal structure of the hermetic compressor, and is also a configuration diagram of a refrigeration cycle of a refrigeration cycle apparatus.
A refrigeration cycle 1 includes a hermetic compressor 2 (hereinafter referred to as "compressor 2"), a condenser 3 acting as a radiator, an expansion device 4, an evaporator 5 acting as a heat sink, an accumulator 6 attached to the compressor 2, and refrigerant pipes that connect the compressor 2, the condenser 3, the expansion device 4, the evaporator 5, and the accumulator 6 in this order. The compressor 2 compresses gas refrigerant. The condenser 3 condenses the gas refrigerant discharged from the compressor 2 to produce liquid refrigerant. The expansion device 4 is a pressure reducer that decompresses the refrigerant. The evaporator 5 evaporates the liquid refrigerant to produce gas refrigerant. The accumulator 6 separates the gas refrigerant and the liquid refrigerant from each other, and supplies the gas refrigerant to the compressor 2. The refrigeration cycle 1 also includes an injection pipe 7 for introducing the liquid refrigerant to the compressor 2 after passing through the condenser 3. The injection pipe 7 is connected to an injection flow path 40 provided to the compressor 2. A regulating valve 8 is provided in the injection pipe 7. The regulating valve 8 reduces the pressure of the refrigerant introduced from the downstream side of the condenser 3, and adjusts an injection flow rate.
The compressor 2 includes a sealed case 10, an electric motor 14 provided in the upper portion of the sealed case 10, and a compression mechanism 17 provided in the lower portion of the sealed case 10. The electric motor 14 includes a stator 15 fixed in the sealed case 10, and a rotor 16 fixed to a rotary shaft 12. The rotor 16 of the electric motor 14 is provided at one end portion of the rotary shaft 12, and an eccentric portion 13 is provided at the other end portion of the rotary shaft 12. The compression mechanism 17 is provided at a position that corresponds to the eccentric portion 13. Thus, the electric motor 14 and the compression mechanism 17 are coupled to each other via the rotary shaft 12.
The compression mechanism 17 includes a cylinder 18 fixed to the sealed case 10. A cylinder chamber 19 is formed inward of the cylinder 18. A main bearing 25 is provided on the upper side of the cylinder 18. A sub-bearing 26 acting as a closing member is provided on the lower side of the cylinder 18. A muffler 27 that forms a muffler chamber 28 is attached to a flange portion 25f of the main bearing 25, and the muffler chamber 28 surrounds the periphery of the flange portion 25f of the main bearing 25.
The eccentric portion 13 of the rotary shaft 12 is disposed in the cylinder chamber 19. A roller 22 is rotatably fitted on the eccentric portion 13. During the rotation of the rotary shaft 12, the roller 22 eccentrically rotates while causing the outer peripheral wall thereof to be brought into line contact with the inner peripheral surface of the cylinder 18 with an oil film interposed therebetween. The cylinder 18 has a blade groove 24. A blade 23 is disposed in the blade groove 24. As shown in Fig. 2, the blade 23 reciprocates in the blade groove 24 while pushing the distal end portion of the blade 23 against the outer peripheral wall of the roller 22. The blade 23 is pushed in a direction along which the distal end portion of the blade 23 is pushed against the outer peripheral wall of the roller 22. The blade 23 partitions the cylinder chamber 19 into two spaces 19a, 19b.
The cylinder 18 has a suction port 20 that introduces gas refrigerant, which is supplied from the accumulator 6, into the cylinder chamber 19. Among the spaces that are partitioned by the blade 23, the space connected to the suction port 20 is referred to as a suction chamber 19a, and the other of the spaces is referred to as a compression chamber 19b. In other words, as shown in Fig. 2, the roller 22 rotates in a counterclockwise direction as viewed in a plan view. The suction port 20 is disposed on the left side of the blade 23. The suction chamber 19a is disposed at the left portion of the cylinder chamber 19, and the compression chamber 19b is disposed at the right portion of the cylinder chamber 19.
The main bearing 25 is provided with a discharge port 25a and a discharge valve 25b shown in Fig. 3, and the discharge valve 25b opens and closes the discharge port 25a. The discharge port 25a allows a refrigerant compressed in the cylinder chamber 19 to be discharged into the sealed case 10 through the muffler chamber 28 in the muffler 27. The discharge valve 25b is provided on the upper surface of the main bearing 25. The discharge valve 25b is formed of a reed valve. The discharge valve 25b opens and closes the discharge port 25a using a differential pressure between the compression chamber 19b and the muffler chamber 28. In other words, the discharge valve 25b opens the discharge port 25a when the pressure in the compression chamber 19b becomes higher than the pressure in the sealed case 10 by a predetermined value. The compressed refrigerant discharged into the sealed case 10 is discharged to the outside of the compressor 2 through a discharge pipe 11.
The discharge port may be provided in the sub-bearing 26. In such a case, a second muffler not shown in the drawing is provided to a flange portion 26f of the sub-bearing 26, and a passage that connects a second muffler chamber, which is formed by the second muffler, and the muffler chamber 28 of the muffler 27, which is provided to the flange portion 25f of the main bearing 25, is provided such that the passage penetrates the cylinder 18 and the main bearing 25. A compressed refrigerant discharged into the muffler chamber from the discharge port of the sub-bearing 26 merges, through the passage, with the compressed refrigerant in the muffler chamber 28 near the main bearing 25.
Next, the injection pipe 7 and the injection flow path 40 will be described. The injection pipe 7 in the first embodiment introduces liquid refrigerant, which is condensed by the condenser 3 of the refrigeration cycle 1, to the compressor 2. The liquid refrigerant, which has passed through the injection pipe 7, flows into the injection flow path 40, and then is injected into the cylinder chamber 19.
Fig. 4 and Fig. 5 are longitudinal cross-sectional views taken along a direction along which a reed valve 60 of a check valve device 44 extends. The portion indicated by a dot-dashed line is a portion shown by a virtual line.
The injection flow path 40 is formed of an injection path 41, a communication path 42, and an introduction path 49. The flow paths 41, 42, 49 are formed in the sub-bearing 26 that closes the lower side of the cylinder chamber 19, and an end plate 30 that is overlapped with the lower side of the flange portion 26f of the sub-bearing 26, and is fixed to the cylinder 18 by a fastening bolt 31.
The injection path 41 is provided in the sub-bearing 26. The injection path 41 has a first opening portion 51 that is opened to the cylinder chamber 19, and a second opening portion 52 that is opened toward the end plate 30. The first opening portion 51 allows liquid refrigerant at an intermediate pressure to be injected therethrough into the cylinder chamber 19. The first opening portion 51 is provided at a position that is opened and closed by the lower surface of the roller 22 in the cylinder chamber 19.
The communication path 42 is defined by the end plate 30 and the sub-bearing 26. The upper end surface of the end plate 30 has a groove portion 43. The communication path 42 is formed by the groove portion 43 that is closed by the end plate 30 that overlaps the sub-bearing 26. The communication path 42 is connected to the injection path 41 through the second opening portion 52 of the injection path 41.
The introduction path 49 is provided parallel to the radial direction of the sub-bearing 26. One end side of the introduction path 49 has a third opening portion 53 that is opened in the axial direction toward the communication path 42. The other end 54 of the introduction path 49 is opened to the outer peripheral surface of the sub-bearing 26. An injection introduction pipe 70, which is connected to the outside of the sealed case 10, is connected to the other end 54 of the introduction path 49. The injection introduction pipe 70 is connected to the injection pipe 7 at a position outside the sealed case 10. The cross-sectional area of the third opening portion 53 of the introduction path 49 is larger than the cross-sectional area of the first opening portion 51 of the injection path 41.
The check valve device 44 is provided in the communication path 42. The check valve device 44 includes the reed valve 60, a valve retainer 64 that regulates the opening degree of the reed valve 60, and a fixing member 65 that fixes the reed valve 60 and the valve retainer 64. The reed valve 60 includes a fixed support portion 61 that is provided at one end of the reed valve 60 and is fixed to the flange portion 26f of the sub-bearing 26, an opening and closing portion 62 that is provided to the other end of the reed valve 60 and opens and closes the third opening portion 53 of the introduction path 49, and a reed portion 63 that couples the fixed support portion 61 and the opening and closing portion 62 to each other. The fixing member 65 may be a rivet, for example.
Fig. 4 shows the injection flow path 40 when the check valve device 44 closes the third opening portion 53 of the introduction path 49. Fig. 5 shows the injection flow path 40 when the check valve device 44 opens the third opening portion 53.
The fixed support portion 61 of the reed valve 60 is fixed to the flange portion 26f of the sub-bearing 26 together with the valve retainer 64 using the fixing member 65, such as a rivet. In other words, the fixed support portion 61 is fixed to the sub-bearing 26 having the introduction path 49. The fixed surface of the reed valve 60 and a valve seat surface 45a of the check valve device 44 are provided on the same plane. Thus, the opening and closing portion 62 of the reed valve 60 is positioned with high accuracy without forming a gap between the opening and closing portion 62 and the valve seat surface 45a.
The fixed support portion 61 is disposed outward of the cylinder chamber 19 in the radial direction of the rotary shaft 12. Fig. 6 is a cross-sectional view taken along line A-A in Fig. 4, and shows the positional relationship between the injection flow path 40 and the check valve device 44. The fixed support portion 61 is provided at a position that has no overlap with the injection flow path 40 as viewed in the axial direction of the rotary shaft 12. When the fixed support portion 61 is fixed using the fixing member 65, the fixing member 65 penetrates through the sub-bearing 26. For this reason, there is a possibility that the fixing member 65 crossing the introduction path 49 may cause a leakage or may become an obstacle of the flow path. However, the fixed support portion 61 is disposed outward of the cylinder chamber 19 in the radial direction of the rotary shaft 12, and is disposed at a position that has no overlap with the injection flow path 40 as viewed in the axial direction of the rotary shaft 12. Accordingly, it is possible to prevent occurrences of the above with certainty.
The check valve device 44 opens and closes the third opening portion 53 of the introduction path 49 by a differential pressure between the introduction path 49 and the communication path 42. The communication path 42 is connected to the cylinder chamber 19 via the injection path 41. In other words, when the pressure in the compression chamber 19b is higher than the pressure in the introduction path 49, the check valve device 44 closes the third opening portion 53 of the introduction path 49. Whereas when the pressure in the compression chamber 19b is lower than the pressure in the introduction path 49 by a predetermined value, the check valve device 44 opens the third opening portion 53 of the introduction path 49.
This predetermined value is larger than a differential pressure between the pressure in the compression chamber 19b and the pressure in the sealed case 10 when the discharge port 25a being opened. The opening and closing of the check valve device 44 caused by a differential pressure depends on the spring constant, the size of a valve member, the size of the discharge hole, and the like of each of the reed valve 60 and the discharge valve 25b.
In such a configuration, the rotor 16 rotates when the electric motor 14 of the compressor 2 is energized. With the rotation of the rotor 16, the compression mechanism 17 is driven via the rotary shaft 12. When the compression mechanism 17 is driven, gas refrigerant separated by the accumulator 6 is suctioned into the suction chamber 19a of the cylinder chamber 19. When the roller 22 passes through the position of the suction port 20 due to the rotation of the roller 22 in the cylinder chamber 19, the first opening portion 51 of the injection path 41 provided in the cylinder 18 is simultaneously opened. The gas refrigerant suctioned from the suction port 20 is compressed due to the rotation of the roller 22. At this point of operation, liquid refrigerant at an intermediate pressure is injected into the compression chamber 19b from the first opening portion 51 of the injection path 41 that is opened and closed due to the rotation of the roller 22. The liquid refrigerant at the intermediate pressure that is injected into the compression chamber 19b evaporates in the compression chamber 19b, thus cooling refrigerant in the compression chamber 19b, and is discharged from the discharge port 25a together with the refrigerant suctioned from the suction port 20. The refrigerant discharged from the discharge port 25a is discharged to the outside of the compressor 2 through the muffler chamber 28. A portion of the refrigerant condensed by the condenser 3 is introduced into the compressor 2 through the injection pipe 7.
The liquid refrigerant that is introduced into the compressor 2 through the injection pipe 7 first flows into the introduction path 49 through the injection introduction pipe 70 of the injection flow path 40. The liquid refrigerant that flows into the introduction path 49 flows toward the third opening portion 53 of the introduction path 49. However, the third opening portion 53 of the introduction path 49 is usually closed by the check valve device 44. In other words, the liquid refrigerant that flows into the introduction path 49 does not flow into the communication path 42. When the pressure in the compression chamber 19b becomes lower than the pressure in the introduction path 49 by a predetermined value, the opening and closing portion 62 of the reed valve 60 of the check valve device 44 is pushed toward the communication path 42, so that the third opening portion 53 of the introduction path 49 is opened. With such opening, the liquid refrigerant in the introduction path 49 flows into the communication path 42. When the pressure in the compression chamber 19b becomes higher than the pressure in the introduction path 49 again, the check valve device 44 closes the third opening portion 53.
The liquid refrigerant that flows into the communication path 42 flows into the injection path 41 through the second opening portion 52 of the injection path 41. As described above, the liquid refrigerant that flows into the injection path 41 is injected into the cylinder chamber 19 when the first opening portion 51 of the injection path 41 is opened, and the first opening portion 51 is opened and closed by the lower surface of the roller 22 that rotates in the cylinder chamber 19.
The injection flow path 40 in the first embodiment has the injection path 41 and the introduction path 49 in the sub-bearing 26, and has the communication path 42 in the end plate 30. However, it is sufficient that the communication path 42 to be defined by combining the sub-bearing 26 and the end plate 30, the third opening portion 53 of the introduction path 49 to be opened in the axial direction of the rotary shaft 12, and the valve seat surface 45a of the check valve device 44 in the communication path 42 and the joint surface between the sub-bearing 26 and the end plate 30 to be on the same plane. For example, the communication path 42 may be provided such that the groove portion 43 is formed on the flange portion 26f of the sub-bearing 26, and the end plate 30 is fixed. In this case, when the introduction path 49 is provided in the end plate 30, the third opening portion 53 is opened in the axial direction. The valve seat surface 45a of the check valve device 44 and the joint surface between the end plate 30 and the sub-bearing 26 are on the same plane. The reed valve 60 opens and closes the third opening portion 53 from above.
According to the compressor 2 of the first embodiment, the injection flow path 40 is formed of the introduction path 49, the communication path 42, and the injection path 41. These flow paths 41, 42, 49 are formed in the sub-bearing 26 and the end plate 30. The introduction path 49 and the injection path 41 are communicated with each other through the communication path 42. With such a configuration, it is possible to increase the design freedom with respect to the position for connecting the introduction path 49 and the injection path 41.
It is preferable that the cross-sectional area of the third opening portion 53 of the introduction path 49 is larger than the cross-sectional area of the first opening portion 51 of the injection path 41. The flow rate of liquid refrigerant in the introduction path 49 becomes larger than the flow rate in the injection path 41, so that the liquid refrigerant is easily injected into the cylinder chamber 19. Further, the flow path resistance caused by the check valve device 44 reduces and hence, flow path loss can be reduced. Accordingly, cooling capacity is improved, so that reliability of the compressor is improved.
Further, the check valve device 44, which prevents the back flow of a compressed refrigerant from the cylinder chamber 19 to the introduction path 49, is provided in the communication path 42 such that the check valve device 44 opens and closes the third opening portion of the introduction path 49. In addition to the above, the opening and closing portion 62 of the reed valve 60 opens and closes in the axial direction. With such a configuration, a back flow can be prevented with certainty, so that a flow path loss is reduced.
The joint surface between the sub-bearing 26and the end plate 30, which form the communication path 42, is required to be sealed. For this reason, this joint surface has small surface roughness, and is formed with high accuracy. The valve seat surface 45a of the check valve device 44 is provided on this joint surface and hence, sealability can be increased.
The reed valve 60 has a thin plate shape, and is fixed in a cantilever manner by the fixed support portion 61. Accordingly, the reed valve 60 has excellent responsiveness. In other words, although the check valve device 44 opens and closes the third opening portion 53 with a fluctuation in the pressure in the compression chamber 19b, deviation in the opening and closing timing can be minimized, so that a reduction in injection flow rate can be prevented. Further, the reed valve 60 is fixed using the fixed support portion 61. Accordingly, the opening and closing portion 62 can stably open and close the third opening portion 53. In addition to the above, a dent or wear caused by irregular movement of the opening and closing portion 62 can be prevented.
A volume V of the check valve device 44 is assumed as the sum of the volume of the reed valve 60, the volume of the valve retainer 64, and the volume of the fixing member 65, and a space capacity C of the communication path 42 is assumed as the size of the groove portion 43. With such an assumption, the volume V of the check valve device 44 is larger than a substantial space capacity S of the communication path 42 that is obtained by subtracting the volume V of the check valve device 44 from the space capacity C of the communication path 42. In other words, the substantial space capacity S of the communication path 42 is equal to or smaller than the volume V of the check valve device 44. Accordingly, the amount of compressed refrigerant that flows back from the cylinder chamber 19 to the injection flow path 40 reduces, so that compression loss can be suppressed.
In the first embodiment, the introduction path 49 and the communication path 42 are provided in the sub-bearing 26 and, as shown in Fig. 4, the communication path 42 is disposed at a position lower than the second opening portion 52 of the injection path 41. Consequently, lubricating oil stays in the communication path 42, thus further reduces the substantial space capacity S of the communication path 42. Performance deterioration of the compressor can be suppressed during a period where the injection into the cylinder chamber 19 is not performed.
Further, as shown in Fig. 6, the injection path 41 is positioned on an extension connecting the center of the fixed support portion 61 of the reed valve 60 and an arbitrary point of the third opening portion 53 of the introduction path 49. In the case where the injection path 41 is provided within this range, when the reed valve 60 opens the third opening portion 53 so that the injection is performed, refrigerant that flows into the communication path 42 substantially linearly flows into the second opening portion 52 that is opened to the injection path 41. Consequently, a flow path resistance can be suppressed, so that a reduction in injection flow rate can be prevented.

(Second embodiment)

A compressor 2 of a second embodiment will be described by referring to Fig. 7 and Fig. 8. Components identical or similar to the corresponding components in the first embodiment are given the same reference numerals, and the repeated description will be omitted when appropriate.
In the compressor 2 of the second embodiment, the compression mechanism 17 includes two cylinders 18A, 18B. An A cylinder 18A is positioned on the lower side, and a B cylinder 18B is positioned on the upper side. A partition plate 32 is provided between the two cylinders 18A, 18B. The partition plate 32, which partitions between the two cylinders 18A, 18B and closes a cylinder chamber 19A of the A cylinder 18A and a cylinder chamber 19B of the B cylinder 18B, includes two partition plate members 32A, 32B that overlap with each other.
The compressor 2 of the second embodiment has the injection flow path 40 provided in the partition plate 32. In other words, the partition plate 32 acts as a closing member that closes the cylinder chamber 19B of the B cylinder 18B, and as an end plate that closes the cylinder chamber 19A of the A cylinder 18A.
As shown in Fig. 7 and Fig. 8, the partition plate member 32B has the injection path 41 from which liquid refrigerant is injected into the cylinder chamber 19B. The partition plate member 32A has an auxiliary injection path 50 from which liquid refrigerant is injected into the cylinder chamber 19A. The injection path 41 has the first opening portion 51 that is opened to the cylinder chamber 19B of the B cylinder 18B, and the second opening portion 52 that is opened to the communication path 42. The auxiliary injection path 50 has a fifth opening portion 71 that is opened to the cylinder chamber 19A of the A cylinder 18A, and a sixth opening portion 72 that is opened to the communication path 42. The communication path 42 is defined by the partition plate member 32B and the partition plate member 32A. The partition plate member 32B has the groove portion 43. The communication path 42 is the groove portion 43 that is closed by the partition plate member 32A that overlaps the partition plate member 32B. The groove portion 43 is closed by the end surface of the partition plate member 32A. The introduction path 49 is provided parallel to the radial direction of the partition plate member 32A. One end side of the introduction path 49 has the third opening portion 53 that is opened to the communication path 42 in the axial direction. The other end 54 of the introduction path 49 is opened to the outer peripheral surface of the partition plate member 32A. The injection introduction pipe 70, which is connected to the outside of the sealed case 10, is connected to the other end 54 of the introduction path 49. The injection introduction pipe 70 is connected to the injection pipe 7 at a position outside the sealed case 10.
The communication path 42 of the compressor 2 of the second embodiment is disposed above the third opening portion 53 of the introduction path 49. The check valve device 44 that opens and closes the third opening portion 53 of the introduction path 49 is provided in the communication path 42. In the check valve device 44 in the second embodiment, the fixed support portion 61 of the reed valve 60 and the valve retainer 64 are fixed to the partition plate member 32A having the introduction path 49 using the fixing member 65. The fixed surface of the reed valve 60 and the valve seat surface 45a of the check valve device 44 are provided on the same plane.
In such a configuration, in the same manner as the first embodiment, liquid refrigerant that flows through the injection pipe 7 is injected into each of the cylinder chambers 19A, 19B through the injection introduction pipe 70, the introduction path 49, the communication path 42, and the injection path 41 or the auxiliary injection path 50. At this point of operation, the check valve device 44 opens and closes the third opening portion 53 of the introduction path 49 by a differential pressure between the pressure in the introduction path 49 and the pressure in each of the cylinder chambers 19A, 19B.
According to the compressor 2 of the second embodiment, even when the compressor 2 is a rotary compressor that includes the two cylinders 18A, 18B, by providing the injection flow path 40 in the partition plate 32 formed of the two partition plate members 32A, 32B, liquid refrigerant can be supplied to the respective cylinder chambers 19A, 19B.
The compressor 2 of the second embodiment includes the check valve device 44 at the third opening portion 53 of the introduction path 49 that is disposed on the upstream of a point where liquid refrigerant that flows into the injection flow path 40 is branched into the injection path 41 and the auxiliary injection path 50. Consequently, the compressor 2 of the second embodiment can block back flow from the respective cylinder chambers 19A, 19B by one check valve device 44.
Further, in the same manner as the compressor of the first embodiment, it may be configured such that the discharge port 25a, through which a compressed refrigerant is discharged, and the discharge valve 25b are provided to each of the main bearing 25 and the sub-bearing 26, and a passage that connects a muffler chamber on the sub-bearing 26 and the muffler chamber 28 on the main bearing 25 is provided. Further, a discharge port and a discharge valve may be provided to the end surfaces of the partition plate 32 for the respective cylinders 18A, 18B. It is preferable that refrigerant that is discharged onto the end surface of the partition plate 32 flows into the passage that connects the muffler chamber on the sub-bearing 26 and the muffler chamber 28 on the main bearing 25. Each discharge valve opens the discharge port 25a by a differential pressure between each cylinder chamber 19A, 19B and the sealed case 10. A differential pressure at which the check valve device 44 provided in the injection flow path 40 opens the third opening portion 53 is higher than a differential pressure at which the discharge port 25a is opened.
According to the compressor 2 of at least one embodiment that has been described heretofore, the injection flow path 40 that introduces liquid refrigerant to the cylinder chamber 19 of the compression mechanism 17 includes the injection introduction pipe 70, the introduction path 49, the injection path 41, the introduction path 49, and the communication path 42 that connects the injection path 41 and the introduction path 49 to each other. The communication path 42 is formed by combining two members, that is, a closing member 26, 32A and the end plate 30, 32B. The introduction path 49 may be formed in either one of the closing member 26, 32A or the end plate 30, 32B. In other words, it is possible to increase the design freedom with respect to the position for connecting the introduction path 49 and the injection path 41. The check valve device 44, which is provided in the communication path 42, opens and closes the third opening portion 53 of the introduction path 49 that is opened in the axial direction of the rotary shaft 12. The valve seat surface 45a is provided on the same plane as the closing member 26, 32A and the end plate 30, 32B that have small surface roughness, and are formed with high accuracy. Consequently, sealability of the valve seat surface 45a can be increased. Thus, back flow of refrigerant from the check valve device 44 can be prevented.
The check valve device 44 includes the reed valve 60. Consequently, deviation in the opening and closing timing can be minimized during the injection, so that a reduction in injection flow rate can be prevented. Further, a dent or wear caused by irregular movement of the opening and closing portion 62 can be reduced.
The check valve device 44 is fixed to a member having the introduction path 49. Consequently, the fixed surface of the reed valve 60 and the valve seat surface 45a of the check valve device 44 are provided on the same plane. The opening and closing portion 62 of the reed valve 60 can be positioned with high accuracy without forming a gap between the opening and closing portion 62 and the valve seat surface 45a.
The fixed support portion 61 of the reed valve 60 is provided at a position that is outward of the cylinder chamber 19 in the radial direction of the rotary shaft 12, and has no overlap with the injection flow path 40 as viewed from the axial direction of the rotary shaft 12. Consequently, it is possible to prevent with certainty that the fixing member 65, which fixes the fixed support portion 61, penetrates the cylinder chamber 19 or the introduction path 49, thus causing a leakage or becoming an obstacle of the flow path. In the embodiment, a rivet is used as the fixing member 65. However, fixing may be performed by other screws.
Further, reducing the space capacity S of the communication path 42 reduces the amount of compressed refrigerant that flows back from the cylinder chamber 19 to the injection flow path 40. Consequently, compression loss is suppressed, and performance deterioration of the compressor can be suppressed during a period where the injection into the cylinder chamber 19 is not performed.
The third opening portion 53 of the introduction path 49 is formed such that the cross-sectional area of the third opening portion 53 is larger than the cross-sectional area of the first opening portion 51 of the injection path 41. With such a configuration, a flow speed in the introduction path 49 becomes higher than a flow speed in the injection path 41, so that refrigerant that flows through the injection flow path 40 can be easily injected into the cylinder chamber 19. Further, increasing the cross section of the third opening portion 53 of the introduction path 49 reduces the flow path resistance of the liquid refrigerant caused by the check valve device 44. Consequently, flow path loss can be reduced. With such a configuration, cooling capacity is improved, so that it is possible to provide the compressor 2 with high reliability.
The compressor 2 of the embodiment is also applicable to the case where a plurality of cylinder chambers 19 are provided. The two partition plate members 32A, 32B are overlapped with each other in the axial direction, and the injection flow path 40 is provided in each of the partition plate members 32A, 32B. With such a structure, it is possible to prevent back flow from the plurality of cylinder chambers 19 with one check valve device 44. Consequently, the structure of the compressor 2 is simplified, so that manufacturability is improved whereby costs can be reduced.
The compressor 2 of the embodiment is a rotary compressor that uses the blade 23 and the roller 22. However, substantially the same advantageous effects can be obtained also in the case where the injection flow path 40 in the embodiment is applied to a swing type compressor where the blade 23 and the roller 22 are provided into an integral body.
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.

REFERENCE SIGNS LIST

1...refrigeration cycle, 2...compressor, 3...condenser, 4...expansion device, 5...evaporator, 6...accumulator, 7...injection pipe, 10...sealed case, 12...rotary shaft, 14...electric motor, 17...compression mechanism, 18...cylinder, 19...cylinder chamber, 22...roller, 23...blade, 25...main bearing, 26...sub-bearing, 30...end plate, 32...partition plate, 32A, 32B...partition plate member, 40...injection flow path, 41...injection path, 42...communication path, 44...check valve device, 49...introduction path, 50...auxiliary injection path, 51...first opening portion, 52...second opening portion, 53...third opening portion, 54...other end of the introduction path, 60...reed valve, 61...fixed support portion, 62...closing portion, 63...reed portion, 64...valve retainer, 65...fixing member, C...space capacity of the communication path, V...volume of the check valve device.

Claims

A hermetic compressor comprising:
a sealed case; and

a compression mechanism accommodated in the sealed case,

wherein the compression mechanism includes
a cylinder having a cylinder chamber,

a closing member fixed to one end surface of the cylinder to close the cylinder chamber,

an end plate overlapped with the closing member,

an injection flow path through which refrigerant is supplied into the cylinder chamber,

a roller configured to compress the refrigerant that flows into the cylinder chamber, and

a check valve device provided in the injection flow path,

wherein the injection flow path includes
an injection path formed in the closing member, and having one end opened to the cylinder chamber and another end opened toward the end plate,

a communication path provided between the closing member and the end plate, and connected to the injection path, and

an introduction path provided in either one of the closing member or the end plate, and having one end and another end, the one end being opened in a direction along which the closing member and the end plate overlap with each other and being connected to the communication path, and the another end being connected to an injection introduction pipe that communicates with an outside of the sealed case,

wherein the check valve device includes
a reed valve that opens and closes the introduction path,

a valve retainer configured to regulate an opening degree of the reed valve, and

a fixing member that fixes the reed valve and the valve retainer, and

wherein the reed valve and the valve retainer are fixed to the closing member or the end plate in which the introduction path is provided.
The hermetic compressor according to claim 1,
wherein a valve seat surface of the reed valve and a joint surface between the closing member and the end plate are on a same plane.
The hermetic compressor according to claim 1 or claim 2, further comprising a discharge hole that allows the refrigerant compressed in the cylinder chamber to be discharged into a sealed case, and a discharge valve that opens and closes the discharge hole,
wherein the check valve device opens a communication-path-side opening portion of the introduction path at a differential pressure higher than a differential pressure at which the discharge valve opens the discharge hole.
The hermetic compressor according to any one of claims 1 to 3, wherein the reed valve includes
a fixed support portion fixed using the fixing member,

an opening and closing portion that opens and closes the communication-path-side opening portion of the introduction path, and

a reed portion coupling the fixed support portion and the opening and closing portion to each other, and

wherein the fixed support portion is disposed at a position that is outward of the cylinder chamber in a radial direction of a rotary shaft that connects the compression mechanism and an electric motor that drives the compression mechanism, and the position that has no overlap with the injection flow path as viewed from an axial direction of the rotary shaft.
The hermetic compressor according to any one of claims 1 to 4, wherein the check valve device is provided in the communication path, and
a volume of the check valve device is larger than a space capacity that is obtained by subtracting the volume of the check valve device from a volume of the communication path.
The hermetic compressor according to claim 5,
wherein at least a portion of the communication path is disposed at a position lower than a communication-path-side opening portion of the injection path.
The hermetic compressor according to any one of claims 1 to 6, wherein the compression mechanism includes a plurality of the cylinders, and
the injection flow path is provided between the plurality of the cylinders.
The hermetic compressor according to claim 7, further comprising
two partition plates that close the cylinder chambers, are arranged between the plurality of the cylinders, and are arranged in an axial direction of a rotary shaft coupling the compression mechanism and an electric motor that drives the compression mechanism to each other,
wherein one of the two partition plates is the closing member, and another of the two partition plates is the end plate.
The hermetic compressor according to claim 7 or claim 8, wherein the injection path is opened to the cylinder chamber of one of the plurality of the cylinders, and the injection path includes an auxiliary injection path that is provided in the end plate, and has one end opened to the cylinder chamber of another of the plurality of the cylinders and another end opened to the communication path.
A refrigeration cycle apparatus comprising:
the hermetic compressor according to any one of claims 1 to 9;

a radiator connected to the hermetic compressor;

an expansion device connected to the radiator; and

a heat sink connected between the expansion device and the hermetic compressor.