Rotary compressor and equipment

Abstract

To provide a rotary compressor that can ensure lubrication performance and maintain good sliding conditions even when liquid-compressing operation is unavoidable, and equipment using the rotary compressor.SOLUTION: A compression mechanism part 30 includes a cylinder 31, a piston 32 that is disposed inside the cylinder 31, and a vane 33 that partitions the interior of the cylinder 31. A shaft 40 has an eccentric part 42. A vane groove 36 in which the vane 33 is disposed is formed in the cylinder 31. The eccentric part 42 is disposed inside the cylinder 31, and the piston 32 fits into the eccentric part 42. The vane 33 operates without separating from the piston 32. At 25°C temperature conditions, a refrigerating machine oil and a working fluid are in a state of two-phase separation.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a rotary compressor in which vanes operate without separating from pistons, and to a device using this rotary compressor. [Background technology]

[0002] Patent Document 1 discloses a rotary compressor in which a cylindrical groove is formed in the piston and a cylindrical portion is formed at the end of the vane to be placed in the cylindrical groove, thereby allowing the vane to operate without separating from the piston. Patent Document 2 discloses a swing rotary compressor that uses an immiscible oil having an incompatible oil content range in the range of -40°C to 31°C. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 3-185291 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-101523 Summary of the Invention [Problem to be solved by the invention]

[0004] When liquid refrigerant is sucked in and compressed, the sealed container is filled with the liquid refrigerant, and a large amount of the liquid refrigerant dissolves in the refrigerating machine oil, causing the viscosity of the refrigerating machine oil to decrease. In the rotary compressor described in Patent Document 1, the piston and vane are not separated, so when liquid refrigerant is drawn into the compression chamber, it is compressed as a liquid. Liquid compression places a much greater load on the compressor than gas compression. In this way, the simultaneous occurrence of a decrease in the viscosity of the refrigerating machine oil and an increase in the load due to liquid compression deteriorates the sliding condition of the compressor. In addition, when an incompatible oil such as that described in Patent Document 2 is discharged from a compressor, it is difficult for it to return to the compressor, and this is likely to cause a shortage of refrigerating machine oil in the compressor.

[0005] Therefore, an object of the present invention is to provide a rotary compressor that can ensure lubrication performance and maintain a good sliding condition even when liquid compression operation is unavoidable, and a device that uses this rotary compressor. [Means for solving the problem]

[0006] The rotary compressor 1 of the present invention according to claim 1 includes an electric motor unit 20 and a compression mechanism unit 30 in a sealed container 10, an oil reservoir 11 for storing refrigerating machine oil is formed at the bottom of the sealed container 10, the sealed container 10 has a suction pipe 12 for guiding a working fluid to the compression mechanism unit 30, and a discharge pipe 13 for guiding the working fluid compressed by the compression mechanism unit 30 to the outside of the sealed container 10, the working fluid compressed by the compression mechanism unit 30 is discharged into the sealed container 10, and then is guided to the outside of the sealed container 10 from the discharge pipe 13, and the electric motor a rotary compressor (1) in which a compressor mechanism (20) and the compression mechanism (30) are connected by a shaft (40), the compression mechanism (30) has a cylinder (31), a piston (32) arranged in the cylinder (31), and a vane (33) that divides the inside of the cylinder (31), the shaft (40) has an eccentric part (42), the cylinder (31) has a vane groove (36) in which the vane (33) is arranged, the eccentric part (42) is arranged in the cylinder (31), the piston (32) is fitted into the eccentric part (42), and the vane (33) operates without being separated from the piston (32), The working fluid is R32, the refrigerating machine oil is alkylbenzene oil, and the refrigerating machine is operated at a speed of 600 rpm or less. In the low rotation range, the compatibility between the working fluid and the refrigerating machine oil is low. Ku, Under a temperature condition of 25°C, the refrigerating machine oil and the working fluid are in a two-phase separated state, In a mixture in which the working fluid is dissolved to the maximum extent in the refrigerating machine oil under a temperature condition of 0°C to 25°C, the ratio of the working fluid is less than 30 wt%. It is characterized by: The present invention described in claim 2 is characterized in that, in the rotary compressor 1 described in claim 1, the piston 32 is formed with a cylindrical groove 32a having an arc angle α exceeding 180°, and the end of the vane 33 is formed with a cylindrical portion 33b that is positioned in the cylindrical groove 32a. The present invention according to a third aspect is characterized in that in the rotary compressor 1 according to the first aspect, no accumulator 14 is provided upstream of the suction pipe 12 . Claim 4The present invention is characterized in that, in the rotary compressor 1 described in claim 1, an accumulator 14 is provided upstream of the suction pipe 12, and the volume of the liquid reservoir section 14f of the accumulator 14 is set to be not more than twice the suction volume formed in the cylinder 31. Claim 5 The device of the invention as described in claims 1 to 1 Claim 4 The rotary compressor 1 according to any one of the above items is used, characterized in that the rotary compressor 1, the condenser 2, the pressure reducing device 3, and the evaporator 4 are connected in a ring shape by piping. [Effects of the Invention]

[0007] According to the present invention, by using a refrigeration oil that has low compatibility with the working fluid, particularly in the low rotation range, it is possible to ensure lubrication performance and maintain a good sliding condition even when liquid compression operation is unavoidable. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view showing a rotary compressor according to an embodiment of the present invention; [Figure 2] View along the line AA in Figure 1 [Figure 3] FIG. 10 is a diagram showing a piston and a vane used in the rotary compressor according to the embodiment. [Figure 4] 5A and 5B are diagrams showing a manufacturing process of a vane used in the rotary compressor according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] A rotary compressor according to a first embodiment of the present invention comprises: The working fluid is R32, the refrigeration oil is alkylbenzene oil, and the rpm is 600 or less. In the low rotation range, the compatibility between the working fluid and the refrigeration oil is low. Ku, At a temperature of 25°C, the refrigerating machine oil and the working fluid are in a two-phase separation state. At temperatures between 0°C and 25°C, the maximum amount of working fluid dissolved in refrigerating oil is less than 30 wt%. According to this embodiment, by using a refrigeration oil that has low compatibility with the working fluid, particularly in the low rotation range, it is possible to ensure lubrication performance and maintain a good sliding state even when liquid compression operation is unavoidable. Furthermore, by using a refrigeration oil that has low compatibility with the working fluid, particularly in the low rotation range, lubrication performance can be ensured and a good sliding condition can be maintained even when liquid compression operation is unavoidable.

[0010] In a second embodiment of the present invention, in the rotary compressor according to the first embodiment, a cylindrical groove having an arc angle exceeding 180° is formed in the piston, and a cylindrical portion is formed at the end of the vane so as to be placed in the cylindrical groove. According to this embodiment, high wear resistance is achieved by the surface support provided by the cylindrical portion and the cylindrical groove.

[0011] The present invention Third In this embodiment, an accumulator is not provided upstream of the suction pipe in the rotary compressor according to the first embodiment. According to this embodiment, even when liquid compression operation is unavoidable, lubrication performance can be ensured and a good sliding state can be maintained, so an accumulator does not need to be provided.

[0012] The present invention Fourth In this embodiment, an accumulator is provided upstream of the suction pipe in the rotary compressor of the first embodiment, and the volume of the liquid reservoir of the accumulator is set to be equal to or less than twice the suction volume formed in the cylinder. According to this embodiment, even when liquid compression operation is unavoidable, lubrication performance can be ensured and a good sliding state can be maintained, so the accumulator can be made smaller.

[0013] The present invention No. 5 The device according to the embodiment includes: Fourth The present invention provides a device using a rotary compressor according to the present embodiment, in which the rotary compressor, a condenser, a pressure reducing device, and an evaporator are connected in a ring shape by piping. According to the present embodiment, a highly reliable device can be provided. [Example]

[0014] FIG. 1 is a cross-sectional view showing a rotary compressor according to an embodiment of the present invention, and FIG. 2 is a view taken along line AA in FIG. The rotary compressor 1 according to this embodiment includes an electric motor section 20 and a compression mechanism section 30 housed within a sealed container 10. The electric motor section 20 and the compression mechanism section 30 are connected by a shaft 40. The electric motor section 20 is composed of a stator 21 fixed to the inner surface of the sealed container 10 and a rotor 22 that rotates within the stator 21 . The compression mechanism 30 has a cylinder 31, a piston 32 disposed in the cylinder 31, and a vane 33 (see FIG. 2) that divides the interior of the cylinder 31. An upper bearing 51 is disposed on one surface of the cylinder 31, and a lower bearing 52 is disposed on the other surface of the cylinder 31. The shaft 40 is made up of a main shaft portion 41 to which the rotor 22 is attached and which is supported by an upper bearing 51 , an eccentric portion 42 to which the piston 32 is attached, and a counter shaft portion 43 which is supported by a lower bearing 52 . The upper bearing 51 is fixed to the sealed container 10. The piston 32 is fitted to the eccentric portion 42 of the shaft 40 that passes through the cylinder 31 so as to be able to rotate freely. An upper cover 53 is provided above the upper bearing 51. A silencing chamber 54 is formed between the upper bearing 51 and the upper cover 53. High-pressure refrigerant gas compressed by the compression mechanism 30 is discharged into the silencing chamber 54. The high-pressure refrigerant gas discharged into the silencing chamber 54 is then discharged into the sealed container 10.

[0015] An oil reservoir 11 is formed at the bottom of the sealed container 10. The oil reservoir 11 stores refrigeration oil. An in-shaft oil supply passage 46 is formed inside the shaft 40 in the axial direction. A communication passage 47 is formed inside the eccentric portion 42 to supply refrigeration oil to the sliding surface of the compression mechanism 30. The refrigeration oil in the oil reservoir 11 is introduced into the shaft oil supply passage 46 from the lower end of the shaft 40. A portion of the refrigeration oil introduced into the shaft oil supply passage 46 is supplied to the sliding surface of the compression mechanism 30 through a communication passage 47. A suction pipe 12 is connected to the side of the sealed container 10, and a discharge pipe 13 is connected to the top of the sealed container 10. The suction pipe 12 guides the refrigerant to the compression mechanism 30. The discharge pipe 13 guides the refrigerant compressed by the compression mechanism 30 and discharged into the sealed container 10 to the outside of the sealed container 10. An accumulator 14 is provided upstream of the suction pipe 12 .

[0016] In the rotary compressor 1 according to this embodiment, a condenser 2, a pressure reducing device 3, and an evaporator 4 are connected in a ring shape by piping. The condenser 2 condenses the refrigerant discharged from a discharge pipe 13. The pressure reducing device 3 reduces the pressure of the refrigerant condensed by the condenser 2. The evaporator 4 evaporates the refrigerant reduced in pressure by the pressure reducing device 3. The refrigerant evaporated in the evaporator 4 is returned to the accumulator 14. The accumulator 14 has an outer cylinder 14a, a refrigerant suction pipe 14b, and a separation plate 14c. An outer cylinder inlet 14d is provided at the top of the outer cylinder 14a, through which the refrigerant is introduced from the evaporator 4. The refrigerant suction pipe 14b has a suction pipe inlet 14e inside the outer cylinder 14a. The separation plate 14c is disposed between the outer cylinder inlet 14d and the suction pipe inlet 14e. A liquid reservoir 14f is formed at the inner bottom of the outer cylinder 14a. The liquid refrigerant is stored in the liquid reservoir 14f. The liquid refrigerant can be stored up to a height H of the suction pipe inlet 14e. Therefore, the volume of the liquid reservoir 14f is up to the height H of the suction pipe inlet 14e. Note that there are no particular limitations on the specific driving method of the rotary compressor 1. For example, the rotary compressor 1 may be driven by simple on / off control, or may be inverter-driven at multiple operating frequencies. In inverter drive, in order to optimize the operational control of the rotary compressor 1, a low rotation region where the rotation speed of the electric motor unit 20 decreases and a high rotation region where the rotation speed of the electric motor unit 20 increases occur.

[0017] The compression chamber 34 shown in FIG. 2 is formed between the upper bearing 51 and the lower bearing 52, between the inner peripheral surface of the cylinder 31 and the outer peripheral surface of the piston 32. The intake pipe 12 is connected to an intake passage 35 of the compression mechanism 30 . The suction passage 35 is connected to the compression chamber 34 . Rotation of the shaft 40 causes the piston 32 to revolve. The vane 33 reciprocates in the vane groove 36 due to the piston 32 revolving along the inner wall surface of the cylinder 31 . Compression chamber 34 is divided by vane 33 into suction space 34a, which communicates with suction passage 35, and compression space 34b, which communicates with discharge hole 37. The suction volume formed in cylinder 31 is the volume of suction space 34a when suction passage 35 is blocked by piston 32, and is the volume when suction space 34a is at its maximum space. The gas refrigerant is drawn into the compression chamber 34 through the suction passage 35 from the suction pipe 12 by the revolution of the piston 32, and is then compressed in the compression chamber 34 and discharged from the discharge hole 37 into the muffling chamber 54. The refrigerant gas discharged into the silencing chamber 54 is discharged into the sealed container 10 and then discharged from the discharge pipe 13 to the outside of the sealed container 10. The high-pressure refrigerant gas discharged to the outside of the sealed container 10 passes through the condenser 2, the pressure reducing device 3, and the evaporator 4, becomes a low-pressure refrigerant gas, and is returned to the compression mechanism 30 via the accumulator 14.

[0018] 3A and 3B are diagrams showing a piston and a vane used in the rotary compressor according to the embodiment, in which FIG. 3A is a perspective view of the piston and the vane separated from each other, FIG. 3B is a plan view of the piston and the vane separated from each other, and FIG. 3C is a perspective view of the vane seen from a different direction.

[0019] A cylindrical groove 32a having an arc angle α of more than 180° is formed on the outer circumferential surface of the piston 32. The cylindrical groove 32a extends from one end face of the piston 32 to the other end face. The vane 33 has a vane side surface 33a that slides in the vane groove 36, a cylindrical portion 33b that is disposed in the cylindrical groove 32a, and a constricted portion 33c that connects the vane side surface 33a and the cylindrical portion 33b. The cylindrical portion 33b is formed at the end of the vane 33. By engaging the cylindrical portion 33b with the cylindrical groove 32a, the vane 33 operates without separating from the piston 32. The cylindrical portion 33b has a notch 33d formed therein, which extends from one end face of the cylindrical portion 33b to the other end face thereof. The notch 33d divides the arcuate surface 33e of the cylindrical portion 33b into a plurality of parts. In this way, the outer peripheral surface of the cylindrical portion 33b has at least two arcuate surfaces 33e separated by the notch 33d. Each arcuate surface 33e has an arcuate angle β of less than 180°, and each cutout portion 33d has an arcuate angle γ of less than 45°. By setting the arc angle γ of the cutout portion 33d to be less than 45°, the contact area between the cylindrical groove 32a and the cylindrical portion 33b can be increased, and refrigerant leakage can be reliably prevented. In this embodiment, the notch 33d is formed at the vane tip of the vane 33. That is, the notch 33d is formed at the tip of the cylindrical portion 33b. Load is less likely to be applied to the vane tip, and by forming the notch 33d at the vane tip, the suction-side arcuate surface 33e1 and the discharge-side arcuate surface 33e2 can be formed symmetrically by the notch 33d. Furthermore, although the notch 33d is formed as a flat surface in this embodiment, the notch 33d may be a curved surface or may not be formed as a single flat surface as long as it is cut out so that the surface is closer to the inner side than the arcuate outer circumferential surface of the cylindrical portion 33b. It is preferable to arrange the two arcuate surfaces 33e formed at positions closest to the virtual plane X extending from the side surface of the vane side surface portion 33a. In this way, the point in the cylindrical portion 33b closest to the virtual plane X extending from the side surface of the vane side surface portion 33a is located on the arcuate surface 33e, thereby reliably preventing refrigerant leakage.

[0020] The Vickers hardness of the surface of the piston 32 is set to Hv 400 or less. By using a low-hardness material for the piston 32, the cylindrical groove 32a can be easily formed, and the surface support between the cylindrical portion 33b and the cylindrical groove 32a provides high wear resistance. The Vickers hardness of the surface of the piston 32 is preferably in the range of Hv80 to Hv400, and more preferably in the range of Hv180 to Hv250. The piston 32 is preferably made of gray cast iron, which makes it easier to form the cylindrical groove 32a.

[0021] The vane side surface portion 33a, i.e., the side surface of the vane 33, is subjected to a surface treatment so that the side surface of the vane 33 has a Vickers hardness exceeding Hv1000. Therefore, the vane groove 36 can have sufficient sliding resistance. Nitriding or DLC treatment is suitable for the surface treatment of the vane side surface portion 33a. By carrying out the nitriding or DLC treatment, the vane side surface portion 33a can be hard-coated.

[0022] The surface hardness of at least a portion of the cylindrical portion 33b is lower than the surface hardness of the vane side surface 33a. Note that "at least a portion of the cylindrical portion 33b" refers to the arcuate surface 33e. The same applies to the following description. By making the surface hardness of at least a portion of the cylindrical portion 33b lower than the surface hardness of the vane side surface 33a, the cylindrical portion 33b is provided with sliding resistance against the vane groove 36, and by making the surface hardness of at least a portion of the cylindrical portion 33b lower than the surface hardness of the vane side surface 33a, the processability and toughness of the cylindrical portion 33b can be improved. It is preferable that the Vickers hardness of at least a part of the cylindrical portion 33b is lower by at least Hv 200 than the Vickers hardness of the vane side surface portion 33a. In other words, by performing a hard coating treatment on the vane side surface portion 33a, the Vickers hardness of the vane side surface portion 33a can be made higher by at least Hv 200 than the Vickers hardness of at least a part of the cylindrical portion 33b, and sufficient sliding resistance to the vane groove 36 can be imparted. The surface hardness of the constricted portion 33c is set lower than the surface hardness of the vane side surface 33a. By setting the surface hardness of the constricted portion 33c lower than the surface hardness of the vane side surface 33a, the workability and toughness of the constricted portion 33c can be improved, and by setting the surface hardness of the vane side surface 33a higher than the surface hardness of the constricted portion 33c, sliding resistance to the vane groove 36 can be imparted. The surface hardness of the constricted portion 33c is preferably set lower than that of the cylindrical portion 33b. By setting the surface hardness of the constricted portion 33c lower than that of the vane side surface portion 33a and the cylindrical portion 33b, the workability and toughness of the constricted portion 33c can be improved. Furthermore, the surface hardness of the arcuate surface 33e is preferably set lower than that of the cutout portion 33d. By setting the surface hardness of the arcuate surface 33e lower than that of the cutout portion 33d, the workability and toughness of the arcuate surface 33e can be improved.

[0023] FIG. 4 is a diagram showing a manufacturing process of the vane used in the rotary compressor according to the embodiment. FIG. 4(a) shows the base material of the vane 33. The vane 33 is made of an iron alloy containing chromium (Cr) as the main component and iron (Fe), or a steel material made of high-carbon steel to which metal materials such as chromium (Cr), tungsten (W), vanadium (V), and molybdenum (Mo) are added. FIG. 4(b) shows the state in which the base material of the vane 33 shown in FIG. 4(a) has been subjected to hard coating treatment. As shown in FIG. 4(c), the base material of the vane 33 that has been subjected to the hard coating treatment is fixed to a jig Y, and a cutting tool Z is used to machine the cylindrical portion 33b and the necked portion 33c. As shown in FIG. 4(c), to form a cylindrical portion 33b with an arc angle α exceeding 180°, finishing must be performed in two or more steps, which reduces the machining accuracy at the joint M of the machined surface. However, by dividing the arcuate surface 33e of the cylindrical portion 33b into a plurality of portions by the cutout portion 33d and setting each arcuate surface 33e to an arc angle β of less than 180°, the machining accuracy of the arcuate surface 33e of the cylindrical portion 33b can be improved. In particular, by forming the notch 33d at the connecting surface M, i.e., the tip of the cylindrical portion 33b, the processing can be performed with just two finishing processes: finishing the suction side arcuate surface 33e1 and finishing the discharge side arcuate surface 33e2.

[0024] The working fluid described as the refrigerant in this embodiment and the refrigerating machine oil are in a two-phase separation state at a temperature of 25°C. By using a refrigerating machine oil that has low compatibility with the working fluid, particularly in the low rotational speed range of the rotary compressor 1, it is possible to ensure lubrication performance and maintain a good sliding state even when liquid compression operation is unavoidable. Here, the low rotational speed range refers to a rotational speed range of 900 rpm or less, particularly 600 rpm or less. Liquid compression is likely to occur in the low rotational speed range, and by ensuring lubrication performance in the low rotational speed range where liquid compression is likely to occur, operation in the low rotational speed range, i.e., low-capacity operation, can be performed stably. Furthermore, in a mixture in which the working fluid is dissolved to the maximum extent in the refrigerating machine oil under temperature conditions of 0° C. to 25° C., the ratio of the working fluid is 1 wt % or more and less than 30 wt %. In this way, by using a refrigerating machine oil that has low compatibility with the working fluid, especially in the low rotation range, it is possible to ensure lubrication performance and maintain a good sliding state even when liquid compression operation is unavoidable.

[0025] In this embodiment, the accumulator 14 is provided upstream of the suction pipe 12, but it is possible to eliminate the accumulator 14. In other words, by using a refrigerating machine oil that has low compatibility with the working fluid, even when liquid compression operation is unavoidable, the lubricating performance of the refrigerating machine oil can be ensured and a good sliding state can be maintained, so that the accumulator 14 does not need to be provided. Furthermore, the volume of the liquid reservoir 14f of the accumulator 14 can be set to no more than twice the suction volume formed in the cylinder 31. That is, by using a refrigeration oil that has low compatibility with the working fluid, even when liquid compression operation is unavoidable, lubrication performance can be ensured and a good sliding state can be maintained, so the accumulator 14 can be made smaller.

[0026] In particular, by using R32 as the working fluid and alkylbenzene oil as the refrigeration oil, compatibility is low, lubrication performance can be ensured, and a good sliding state can be maintained. Furthermore, by using carbon dioxide as the working fluid and polyalkylene glycol oil as the refrigerating machine oil, compatibility is low, lubricating performance can be ensured, and a good sliding state can be maintained. Furthermore, by using R290 as the working fluid and polyalkylene glycol oil as the refrigeration oil, compatibility is low, lubrication performance can be ensured, and a good sliding state can be maintained. The refrigerating machine oil preferably has a kinematic viscosity of 35 mm / s or less.

[0027] The equipment according to this embodiment, in which the rotary compressor 1, the condenser 2, the pressure reducing device 3, and the evaporator 4 are connected in a ring shape by piping, is highly reliable. [Industrial Applicability]

[0028] An apparatus using the rotary compressor of the present invention is useful as a refrigeration cycle apparatus such as a hot water heating apparatus, an air conditioner, a water heater, a refrigerator, a showcase, a chiller, a dehumidifier, or a refrigerator. [Explanation of symbols]

[0029] 1 Rotary compressor 2 Condenser 3. Pressure reducing device 4. Evaporator 10. Airtight containers 11 Oil sump 12 Suction pipe 13 Discharge pipe 14 Accumulator 14a Outer cylinder 14b Refrigerant suction pipe 14c Separation plate 14d Outer cylinder inlet 14e Suction pipe inlet 14f Liquid reservoir 20 Electric motor section 21 Stator 22 Rotor 30 Compression mechanism 31 cylinders 32 piston 32a Cylindrical groove 33 Vane 33a Vane side 33b Cylindrical part 33c waist 33d Notch 33e Arc surface 33e1 Intake side arc surface 33e2 Discharge side arc surface 34 Compression chamber 34a Suction space 34b Compressed Space 35 Suction passage 36 Vane groove 37 Discharge hole 40 shaft 41 Main shaft section 42 Eccentric part 43 Secondary shaft part 46 Oil supply passage inside shaft 47 Communication path 51 Upper bearing 52 Lower bearing 53 Upper cover 54 Sound deadening room H Height M Joint surface X-extension virtual plane Y jig Z cutting tool α, β, γ arc angles

Claims

1. A motor unit and a compression mechanism unit are provided in a sealed container, an oil reservoir for storing refrigeration oil is formed at the bottom of the sealed container; The sealed container has a suction pipe that introduces the working fluid into the compression mechanism, and a discharge pipe that introduces the working fluid compressed by the compression mechanism to the outside of the sealed container, the working fluid compressed by the compression mechanism is discharged into the sealed container and then guided to the outside of the sealed container through the discharge pipe, The electric motor unit and the compression mechanism unit are connected by a shaft, The compression mechanism includes a cylinder, a piston disposed in the cylinder, and a vane that divides the interior of the cylinder. the shaft has an eccentric portion; a vane groove in which the vane is disposed is formed in the cylinder; the eccentric portion is disposed within the cylinder; The piston is fitted to the eccentric portion, A rotary compressor in which the vanes operate without separating from the pistons, At a temperature of 25°C, the refrigerating machine oil and the working fluid are in a two-phase separated state. A rotary compressor characterized by:

2. The piston is formed with a cylindrical groove having an arc angle of more than 180°. The end of the vane is formed with a cylindrical portion that is disposed in the cylindrical groove.

2. The rotary compressor according to claim 1, wherein:

3. In a mixture in which the working fluid is dissolved to the maximum extent in the refrigerating machine oil under a temperature condition of 0°C to 25°C, the ratio of the working fluid is less than 30 wt%.

2. The rotary compressor according to claim 1, wherein:

4. No accumulator is provided upstream of the intake pipe 2. The rotary compressor according to claim 1, wherein:

5. an accumulator is provided upstream of the suction pipe; The volume of the liquid reservoir of the accumulator is set to be equal to or less than twice the suction volume formed in the cylinder.

2. The rotary compressor according to claim 1, wherein:

6. The working fluid is R32, and the refrigerating machine oil is alkylbenzene oil. The rotary compressor according to any one of claims 1 to 5.

7. The working fluid is carbon dioxide, and the refrigerating machine oil is polyalkylene glycol oil. The rotary compressor according to any one of claims 1 to 5.

8. The working fluid is R290, and the refrigerating machine oil is polyalkylene glycol oil. The rotary compressor according to any one of claims 1 to 5.

9. A device using the rotary compressor according to any one of claims 1 to 5, The rotary compressor, the condenser, the pressure reducing device, and the evaporator are connected in a ring shape by piping. The device characterized by:

Images