Compressor and refrigeration device

Abstract

Provided is a compressor capable of suppressing a sudden drop in the oil level of refrigerating machine oil. The compressor comprises a casing (20), a compression mechanism (30), a drive shaft (40), a motor (50), and a partition member (80). The casing stores the refrigerating machine oil. The compression mechanism compresses a refrigerant stored inside the casing. The drive shaft drives the compression mechanism. The motor comprises a stator (51) and rotates the drive shaft. The partition member is disposed below the motor. The partition member partitions a side close to the motor and a side far from the motor. The refrigerating machine oil mixed with the refrigerant in the casing is separated into a first layer (L1) and a second layer (L2) in a stopped state. The second layer is positioned above the first layer. The lower end (H1) of the partition member is positioned above the upper end (H2) of the first layer.

Description

Compressors and refrigeration equipment

[0001] This invention relates to a compressor and a refrigeration device.

[0002] Patent Document 1 (JP 2024-13789 A) discloses a refrigeration system using a scroll compressor. Hydrofluorocarbon (HFC) refrigerants have traditionally been used in refrigeration systems. However, in recent years, the use of propane (R290) refrigerant has been increasing in response to F-gas regulations in Europe and other global environmental conservation efforts.

[0003] When R290 refrigerant is used in place of HFC refrigerant, the amount of R290 refrigerant that dissolves in the refrigerating machine oil increases, and depending on the conditions, there is a risk that the oil level of the refrigerating machine oil may drop suddenly.

[0004] A compressor according to a first aspect has a casing, a compression mechanism, a drive shaft, a motor, and a partition member. The casing stores refrigeration oil. The compression mechanism compresses a refrigerant housed inside the casing. The drive shaft drives the compression mechanism. The motor has a stator and rotates the drive shaft. The partition member is disposed below the motor. The partition member separates a side closer to the motor from a side farther from the motor. Refrigeration oil mixed with the refrigerant inside the casing separates into a first layer and a second layer when the compressor is stopped. The second layer is located above the first layer. The lower end of the partition member is located above the upper end of the first layer.

[0005] With this configuration, when the compressor is stopped, the refrigerating machine oil mixed with the refrigerant separates into a first layer and a second layer, and the lower end of the partition member is located above the upper end of the first layer. Therefore, when the compressor is stopped, the partition member prevents the first layer from rising, thereby preventing a sudden drop in the refrigerating machine oil level.

[0006] A compressor according to a second aspect is the compressor according to the first aspect, wherein the height of the lower end of the partition member is located below the height of the oil surface of the second layer.

[0007] A compressor according to a third aspect is the compressor according to the first or second aspect, wherein the refrigeration oil is an immiscible oil that is immiscible with the refrigerant.

[0008] A compressor according to a fourth aspect is the compressor according to the third aspect, wherein the refrigeration oil contains any one of polyalkylene glycol, polyvinyl ether, and polyol ester.

[0009] A compressor according to a fifth aspect is the compressor according to the fourth aspect, wherein the refrigerating machine oil is a mono-ol polyalkylene glycol.

[0010] A compressor according to a sixth aspect is the compressor according to any one of the first aspect to the fifth aspect, wherein the liquid density of the first layer, calculated by dividing the mass of the mixed liquid of the refrigerant and the refrigerating machine oil by the volume, is greater than the liquid density of the second layer.

[0011] A compressor according to a seventh aspect is the compressor according to any one of the first aspect to the sixth aspect, wherein the concentration of the refrigerating machine oil in the first layer is higher than the concentration of the refrigerating machine oil in the second layer.

[0012] A compressor according to an eighth aspect is the compressor according to any one of the first aspect to the seventh aspect, wherein the refrigerant is a natural refrigerant.

[0013] A compressor according to a ninth aspect is the compressor according to the eighth aspect, wherein the refrigerant is a single refrigerant made of hydrocarbon or a mixed refrigerant containing hydrocarbon.

[0014] A compressor according to a tenth aspect is the compressor according to the ninth aspect, wherein the refrigerant is propane.

[0015] A refrigeration device according to an eleventh aspect includes the compressor according to any one of the first to tenth aspects.

[0016] Fig. 1 is a refrigerant circuit diagram showing the configuration of a refrigeration device of the present embodiment. Fig. 2 is a longitudinal sectional view showing the configuration of a compressor. Fig. 3 is a perspective view of a lower bearing and an oil separation member. Fig. 4 is a plan view of the lower bearing and the oil separation member. Fig. 5 is a longitudinal sectional view showing the configuration of a compressor in a state in which a two-layer separation region has occurred. Fig. 6 is a view showing the two-layer separation region. Fig. 7 is another longitudinal sectional view showing the configuration of a compressor in a state in which a two-layer separation region has occurred. Fig. 8 is a perspective view of a lower bearing and an oil separation member in a modified example.

[0017] In the following description, expressions indicating directions such as "up" and "down" are used as appropriate, and these refer to the directions when the refrigeration apparatus 100 is installed and in normal use. For example, the up-down direction is the vertical direction. The vertical direction is the direction parallel to the direction of gravity.

[0018] (1) Overall Configuration of Refrigeration System 100 As shown in Fig. 1, the refrigeration system 100 has a refrigerant circuit 100a filled with refrigerant. The refrigerant circuit 100a has a compressor 10, a radiator 3, a pressure reduction mechanism 4, and an evaporator 5. The compressor 10 is a scroll compressor. The pressure reduction mechanism 4 is, for example, an expansion valve. The refrigerant circuit 100a performs a vapor compression refrigeration cycle.

[0019] The refrigeration system 100 is an air conditioning system. The air conditioning system may be a cooling-only system, a heating-only system, or an air conditioning system that switches between cooling and heating. In this case, the air conditioning system has a switching mechanism (e.g., a four-way switching valve) that switches the refrigerant circulation direction. The refrigeration system 100 may be a water heater, a chiller unit, a cooling system that cools the air inside a storage unit, or the like. A cooling system cools the air inside a refrigerator, a freezer, a container, or the like.

[0020] (2) Compressor 10 As shown in FIG. 2 , the compressor 10 includes a casing 20 , a compression mechanism 30 , a drive shaft 40 , a motor 50 , and a partition member 80 .

[0021] (2-1) Casing 20 The casing 20 is formed in a vertically long cylindrical shape and configured as a sealed dome type. The casing 20 houses the motor 50 and the compression mechanism 30.

[0022] An oil reservoir 21 is provided at the bottom of the casing 20. Refrigeration oil is stored in the oil reservoir 21. A suction pipe 12 is connected to the top of the casing 20. A discharge pipe 13 is connected to the body of the casing 20.

[0023] A housing 27 is fixed to the casing 20. The housing 27 is fixed inside the casing 20 by, for example, shrink fitting. The housing 27 is disposed above the motor 50. The compression mechanism 30 is disposed above the housing 27. The inlet end of the discharge pipe 13 is located between the motor 50 and the housing 27.

[0024] A recess 53 is formed in the housing 27. The recess 53 is formed by recessing a portion of the upper surface of the housing 27. An upper bearing 27a is provided below the recess 53.

[0025] An oil drain passage 27b is provided in the housing 27. The oil drain passage 27b is a passage for draining the lubricating oil that has flowed into the recess 53 to the outside of the housing 27. The upstream end of the oil drain passage 27b is connected to the recess 53. An oil return member 56 is disposed downstream of the oil drain passage 27b.

[0026] The oil return member 56 guides downward the lubricating oil discharged from the recess 53 toward the oil discharge passage 27b. A guide plate 57 is disposed below the oil return member 56.

[0027] The guide plate 57 guides the lubricating oil discharged from the oil return member 56 to the oil return passage 35 of the motor 50. The guide plate 57 is formed from a tapered plate material whose opening width narrows from top to bottom. The lower part of the oil return member 56 is inserted into the upper part of the guide plate 57. The lower part of the guide plate 57 extends so as to pass through the gap between the casing 20 and the coil part of the motor 50, and the gap in the oil return passage 35.

[0028] (2-2) Compression Mechanism 30 The compression mechanism 30 includes a fixed scroll 60 and a movable scroll 70. The fixed scroll 60 is fixed to the upper surface of the housing 27. The movable scroll 70 is disposed between the fixed scroll 60 and the housing 27.

[0029] The fixed scroll 60 has a fixed end plate 61, a fixed side wrap 62, and an outer peripheral wall 63. The outer peripheral wall 63 is formed in a substantially cylindrical shape and stands on the outer edge of the front surface (the lower surface in FIG. 2 ) of the fixed end plate 61.

[0030] The fixed-side wrap 62 is formed in a spiral shape and stands inside the outer peripheral wall 63 of the fixed-side end plate 61 .

[0031] The fixed side end plate 61 is located on the outer periphery and is formed continuously with the fixed side wrap 62. The tip end surface of the fixed side wrap 62 and the tip end surface of the outer periphery wall 63 are formed to be substantially flush with each other. The fixed scroll 60 is fixed to the housing 27.

[0032] The movable scroll 70 has a movable end plate 71, a movable side wrap 72, and a boss portion 73. The movable side wrap 72 is formed in a spiral shape. The movable side wrap 72 is formed on the upper surface of the movable side end plate 71. The movable side wrap 72 meshes with the fixed side wrap 62.

[0033] The boss portion 73 is formed at the center of the lower surface of the movable-side end plate 71. The eccentric portion 42 of the drive shaft 40 is inserted into the boss portion 73, and the drive shaft 40 is connected thereto.

[0034] An Oldham coupling 45 is provided on the upper part of the housing 27. The Oldham coupling 45 prevents the movable scroll 70 from rotating on its axis.

[0035] The compression mechanism 30 has a fluid chamber S into which the refrigerant flows. The fluid chamber S is formed between the fixed scroll 60 and the movable scroll 70. The movable scroll 70 is disposed so that the movable wrap 72 meshes with the fixed wrap 62 of the fixed scroll 60. Here, the lower surface of the outer peripheral wall 63 of the fixed scroll 60 serves as the surface facing the movable scroll 70. In addition, the upper surface of the movable end plate 71 of the movable scroll 70 serves as the surface facing the fixed scroll 60.

[0036] An intake port 64 is formed in the outer peripheral wall 63 of the fixed scroll 60. The intake port 64 opens near the end of the fixed side wrap 62. The downstream end of the intake pipe 12 is connected to the intake port 64.

[0037] A discharge port 65 is formed in the center of the fixed side end plate 61 of the fixed scroll 60. The discharge port 65 opens in the upper surface of the fixed side end plate 61 of the fixed scroll 60. The high-pressure gas refrigerant discharged from the discharge port 65 flows through a passage (not shown) formed in the housing 27 into the upper space 24 below the housing 27 and above the motor 50.

[0038] The recess 53 of the housing 27 communicates with the oil supply passage 16 of the drive shaft 40 via the inside of the boss portion 73 of the movable scroll 70. When high-pressure lubricating oil is supplied to the recess 53, a high pressure corresponding to the discharge pressure of the compression mechanism 30 acts on the recess 53. The high pressure in the recess 53 presses the movable scroll 70 against the fixed scroll 60.

[0039] An oil passage 55 is formed inside the housing 27 and the fixed scroll 60. The inlet end of the oil passage 55 communicates with the recess 53 of the housing 27. The outlet end of the oil passage 55 opens to the opposing surface of the fixed scroll 60. The oil passage 55 supplies high-pressure lubricating oil in the recess 53 to the opposing surface between the movable end plate 71 of the movable scroll 70 and the outer peripheral wall 63 of the fixed scroll 60.

[0040] (2-3) Drive Shaft 40 The drive shaft 40 extends in the vertical direction along the central axis of the casing 20. The drive shaft 40 has a main shaft portion 41 and an eccentric portion 42.

[0041] The eccentric portion 42 is provided at the upper end of the main shaft portion 41. The lower portion of the main shaft portion 41 is rotatably supported by the lower bearing 22. The lower bearing 22 is fixed to the inner circumferential surface of the casing 20. For example, a positive displacement pump 23 is provided in the lower bearing 22. The upper portion of the main shaft portion 41 passes through the housing 27 and is rotatably supported by the upper bearing 27a of the housing 27.

[0042] A balance weight 18 is provided on the drive shaft 40. The balance weight 18 is disposed in the upper space 24 above the rotor 52 of the motor 50.

[0043] An oil supply passage 16 is formed inside the drive shaft 40. The oil supply passage 16 extends vertically from the lower end to the upper end of the drive shaft 40. The lower end of the drive shaft 40 is connected to a pump 23. The lower end of the pump 23 is immersed in an oil reservoir 21. As the drive shaft 40 rotates, the pump 23 draws up lubricating oil from the oil reservoir 21 and transports it to the oil supply passage 16. The oil supply passage 16 supplies the lubricating oil from the oil reservoir 21 to the sliding surfaces between the lower bearing 22 and the drive shaft 40, the sliding surfaces between the upper bearing 27a and the drive shaft 40, and the sliding surfaces between the boss portion 73 and the drive shaft 40. The oil supply passage 16 opens to the upper end surface of the drive shaft 40 and supplies the lubricating oil above the drive shaft 40.

[0044] (2-4) Motor 50 The motor 50 includes a stator 51 and a rotor 52 .

[0045] The stator 51 is fixed to the inner peripheral surface of the casing 20. Coils 51a are wound in a concentrated manner around teeth (not shown) of the stator 51.

[0046] The rotor 52 is disposed inside the stator 51. The drive shaft 40 passes through the rotor 52. The rotor 52 is fixed to the drive shaft 40. The rotor 52 is formed with rotor holes 52a that pass through in the axial direction. A plurality of the rotor holes 52a are formed at intervals in the circumferential direction.

[0047] (2-5) Partition Member 80 The partition member 80 is disposed in the lower space 26 below the stator 31. The partition member 80 divides the space below the stator 51 into a first space 26 and a second space 27.

[0048] The first space 26 is a space farther from the motor 50. The first space 26 is a space including the oil reservoir 21 at the bottom of the casing 20.

[0049] The second space 27 is a space closer to the motor 50. The second space 27 is also located above the first space 26. The second space 27 is a space into which the refrigerant flows.

[0050] 3 and 4 , the partition member 80 is formed of a ring-shaped plate material. The partition member 80 is attached to the lower bearing 22. The attachment position of the partition member 80 to the lower bearing 22 is not particularly limited. The partition member 80 is attached to, for example, the lower surface of the lower bearing 22. The outer circumferential surface of the partition member 80 extends to a position where it abuts against the inner circumferential surface of the casing 20.

[0051] 5, the lower end H1 of the partition member 80 is located above the upper end H2 of the first layer L1 for the following reason.

[0052] In the lower space 26, which is the space between the motor 50 and the partition member 80, the refrigerant swirls as the motor 50 rotates. This swirl can cause the refrigeration oil stored in the oil reservoir 21 to be stirred up and flow up and out of the casing 20, a phenomenon known as "oil rising."

[0053] Furthermore, if the compressor is stopped for an extended period of time in an environment with low ambient temperatures, a large amount of refrigerant dissolves in the refrigerant oil, a so-called "stagnation state." When the compressor 10 is started in this state, the refrigerant components in the mixed liquid may suddenly vaporize, causing foaming. This foaming may cause the refrigerant oil to rise along with the bubbles and be discharged from the oil reservoir. If this oil rising phenomenon occurs, the amount of lubricating oil may be insufficient, potentially causing instability in the lubrication supply to the sliding parts and bearings of the compressor 10.

[0054] Here, by setting the lower end H1 of the partition member 80 above the upper end H2 of the first layer L1, the path of oil rise is physically blocked, and the refrigeration oil in the oil reservoir 21 is prevented from being blown up to the top of the casing 20. As a result, even when the compressor is stopped, the refrigeration oil remains appropriately within the oil reservoir 21, preventing a sudden drop in the oil level. The partition member 80 can prevent the refrigeration oil from being discharged from the oil reservoir 21.

[0055] Meanwhile, the lower end H1 of the partition member 80 is located below the upper end H3 of the second layer L2. Furthermore, the distance between the lower end H1 of the partition member 80 and the upper end H3 of the second layer L2 is greater than the distance between the lower end H1 of the partition member 80 and the upper end H2 of the first layer L1. The reason for this is as follows: The second layer L2 contains more refrigerant than the first layer L1. Therefore, in the "dead state," a larger amount of refrigerant dissolves in the refrigerant oil in the second layer L2. Because the lower end H1 of the partition member 80 is located below the upper end H3 of the second layer L2, bubbles and refrigerant generated by foaming can easily escape upward, allowing the refrigerant and oil to be separated and redistributed quickly. This ensures that the refrigerant oil is appropriately retained in the oil reservoir 21 even during restart, ensuring lubrication and enabling stable system operation.

[0056] In this embodiment, the upper end H2 of the first layer L1, the lower end H1 of the partition member 80, and the upper end H3 of the second layer L2 are arranged in this order in height, so that the discharge of refrigeration oil is suppressed while the flow of refrigerant is not hindered both when the unit is stopped and when it is restarted.

[0057] An outflow passage 81 is formed in the partition member 80. The outflow passage 81 allows the refrigerating machine oil and R-290 mixture and the refrigerating machine oil to pass through. The outflow passage is formed in the shape of an elongated hole extending in the circumferential direction. A plurality of the outflow passages are provided at intervals in the circumferential direction.

[0058] The partition member 80 is formed with a notch 82. The notch 82 allows the lubricating oil collected on the partition member 80 to fall into the oil reservoir 21.

[0059] (3) Refrigerant and Refrigeration Oil In this embodiment, the refrigerant used in the compressor 10 is propane (R290). The refrigerant is not limited to propane, as long as it is a single refrigerant made of a hydrocarbon or a mixed refrigerant containing a hydrocarbon. The hydrocarbon may be selected from the group consisting of propane, butane, and isobutane. The refrigerant may also be a natural refrigerant other than a hydrocarbon. The natural refrigerant may include, for example, at least one of carbon dioxide, ammonia, and water.

[0060] In this embodiment, the refrigeration oil used in the compressor 10 is a mono-ol polyalkylene glycol, which is an incompatible oil. An incompatible oil is incompatible with the refrigerant. A mono-ol polyalkylene glycol is a polyalkylene glycol having one hydroxyl group at its terminal. The refrigeration oil is not limited to a mono-ol polyalkylene glycol, as long as it is an incompatible oil containing either a polyalkylene glycol, a polyvinyl ether, or a polyol ester. Hereinafter, the mono-ol polyalkylene glycol, which is the refrigeration oil used in the compressor 10, will be referred to as "PAG oil."

[0061] As shown in Figures 5 and 6, when R-290 is mixed into PAG oil, the mixture separates into two layers, a first layer L1 and a second layer L2, depending on the R-290 mixed and the temperature conditions. When the compressor 10 is stopped, the mixture separates into two layers, a first layer L1 and a second layer L2. The second layer L2 is located above the first layer L1. In the first layer L1, the PAG oil content is greater than the R-290 content. In the second layer L2, the R-290 content is greater than the PAG oil content. Therefore, the liquid density of the first layer L1 is greater than that of the second layer L2. Here, the liquid density is the mass of the mixture of R-290 and PAG oil divided by the volume.

[0062] The concentration of PAG oil in the first layer L1 is greater than the concentration of PAG oil in the second layer L2. The concentration of PAG oil corresponds to the content (wt%) of PAG oil in the mixture. Specifically, the concentration of PAG oil is the mass of PAG oil contained in the mixture divided by the mass of the mixture. The density of PAG oil is greater than the density of propane. Therefore, the density of the mixture in the first layer L1 is greater than the density of the mixture in the second layer L2.

[0063] The volume resistivity of the second layer L2 is 1.0×10 １０ The volume resistivity is Ω·m or more. Volume resistivity is a physical property that represents the volume resistance value per unit volume of the test object. The lower the volume resistivity, the lower the electrical insulation. The volume resistivity is measured at room temperature of 25°C in accordance with IEC 60247.

[0064] An upper end H3 of the second layer L2 is located above a lower end H1 of the stator 51. The lower end H1 of the stator 51 is the lower end of the coil 30a that is wound concentratedly around the stator 51.

[0065] (4) Operation The basic operation of the compressor 10 will now be described. In Fig. 2, when the motor 50 is operated, the drive shaft 40 to which the rotor 52 is fixed is driven to rotate. Furthermore, the movable scroll 70 is prevented from rotating by the Oldham coupling 45, and therefore orbits about the axis of the drive shaft 40.

[0066] When the movable scroll 70 orbits, the refrigerant is compressed in the fluid chamber S. The high-pressure gas refrigerant compressed in the fluid chamber S is discharged from the discharge port 65 and flows into the upper space 24 through a passage (not shown) formed in the housing 27.

[0067] A portion of the refrigerant that flows out into the upper space 24 flows into the motor 50 and flows downward along the inner circumferential surface of the casing 20. The refrigerant that flows out of the motor 50 flows toward the upper space 24 through rotor holes 52a formed in the rotor 52. This flow of refrigerant can cool the motor 50.

[0068] The high-pressure gas refrigerant flowing through the upper space 24 is discharged to the outside of the casing 20 via the discharge pipe 13 .

[0069] As the drive shaft 40 rotates, the high-pressure lubricating oil in the oil reservoir 21 is sucked up by the pump 23 , flows upward through the oil supply passage 16 of the drive shaft 40 , and flows out from the opening at the upper end of the eccentric portion 42 of the drive shaft 40 .

[0070] The lubricating oil that flows out from the opening at the upper end of the eccentric portion 42 of the drive shaft 40 flows into the inside of the boss portion 73 of the movable scroll 70 .

[0071] The lubricating oil supplied to the boss portion 73 flows into the recessed portion 53 of the housing 27 through the gap between the eccentric portion 42 of the drive shaft 40 and the boss portion 73. As a result, the recessed portion 53 of the housing 27 becomes high pressure corresponding to the discharge pressure of the compression mechanism 30. The high pressure in the recessed portion 53 presses the movable scroll 70 against the fixed scroll 60.

[0072] The lubricating oil flowing out from the opening at the upper end of the eccentric portion 42 of the drive shaft 40 spreads over the sliding surface of the Oldham coupling 45, lubricating the Oldham coupling 45. The lubricating oil further lubricates the thrust sliding surface on which the fixed scroll 60 and the movable scroll 70 slide.

[0073] After lubricating each part, the lubricating oil is discharged and returned to the oil reservoir 21. The guide plate 57 guides the lubricating oil discharged from the oil return member 56 to the oil return passage 35 of the motor 50.

[0074] (5) Features (5-1) R-290 refrigerant dissolves in a larger amount in refrigeration oil (PAG oil in this embodiment) than HFC refrigerant. In particular, when the refrigerant stagnates due to low ambient temperatures, a large amount of R-290 refrigerant dissolves in the PAG oil. Therefore, when the refrigerant is compressed in a stagnant state (stagnant start-up), the refrigerant components in the mixed liquid may suddenly vaporize, causing foaming. The foamed PAG oil flows along with the R-290 and flows out of the casing 20 through the discharge pipe 12 and is discharged as oil rise. This may cause the PAG oil level to drop rapidly, potentially impairing the lubrication of the compressor 10.

[0075] Furthermore, in the lower space 26, which is the space between the motor 50 and the partition member 80, the R-290 rotates as the motor 50 rotates. This rotation causes the PAG oil in the oil reservoir 21 to be swirled up. This swirling also contributes to the oil rising, and there is a possibility that the PAG oil will be discharged.

[0076] In this embodiment, when the compressor 10 is stopped, the mixed liquid separates into two layers: a first layer L1 and a second layer L2. The second layer L2 is located above the first layer L1. The lower end H1 of the partition member 80 is located above the upper end H2 of the first layer. Therefore, the partition member 80 can prevent the PAG oil in the oil reservoir 21 from being blown up. As a result, the partition member 80 can prevent the PAG oil from being discharged from the oil reservoir 21.

[0077] Furthermore, even if rapid foaming occurs during start-up after slumping, the mixed liquid is returned to the oil reservoir 21 by the partition member 80. Therefore, a rapid drop in the PAG oil level can be suppressed.

[0078] (5-2) The second layer L2 contains a higher amount of R-290 than the PAG oil. Therefore, in the second layer L2, a large amount of R-290 dissolves in the PAG oil during aging. When the compressor 10 starts in this state, the dissolved R-290 may suddenly vaporize, causing foaming. When foaming occurs, it is necessary to quickly return the R-290 to the refrigerant circuit 100a.

[0079] In this embodiment, the height H1 of the lower end of the partition member 80 is located below the height H3 of the oil level in the second layer L2, so that the partition member 80 promotes the flow of R-290 without physically obstructing the upward flow of R-290. As a result, R-290 that rises due to foaming is quickly discharged to the outside of the casing 20, making it easier to quickly eliminate the stagnation (deadlock) of R-290.

[0080] In this embodiment, by arranging the upper end H2 of the first layer L1, the lower end H1 of the partition member 80, and the upper end H3 of the second layer L2 in this order in height, it is possible to suppress the discharge of PAG oil while promoting the return of R-290 to the refrigerant circuit 100a.

[0081] (5-3) The refrigerating machine oil is an incompatible oil that is incompatible with the refrigerant. In this case, when R-290 is mixed with the refrigerating machine oil, the mixture separates into a first layer L1 and a second layer L2 when the compressor 10 is stopped.

[0082] (5-4) The refrigerating machine oil contains any one of polyalkylene glycol, polyvinyl ether, and polyol ester. In this case, when R-290 is mixed with the refrigerating machine oil, the mixture separates into a first layer L1 and a second layer L2 when the compressor 10 is stopped.

[0083] (5-5) The refrigerating machine oil is a mono-ol polyalkylene glycol. In this case, when R-290 is mixed with the refrigerating machine oil, the mixture separates into a first layer L1 and a second layer L2 when the compressor 10 is stopped.

[0084] (5-6) The liquid density of the first layer is greater than the liquid density of the second layer. The liquid density is the mass of the mixture of the refrigerant and the refrigerating machine oil divided by the volume.

[0085] (5-7) The concentration of the refrigerating machine oil in the first layer is greater than the concentration of the refrigerating machine oil in the second layer.

[0086] (5-8) The refrigerant is a natural refrigerant.

[0087] (5-9) The refrigerant is a single refrigerant made of hydrocarbon or a mixed refrigerant containing hydrocarbon.

[0088] (5-10) The refrigerant is propane.

[0089] (6) Modifications (6-1) Modification A In the above embodiment, the partition member 80 is a ring-shaped plate material, but is not limited to this. The partition member 80 may be, for example, a mesh-like material.

[0090] (6-2) Modification B In the above embodiment, the partition member 80 is attached to the lower bearing 22, but this is not particularly limited. The partition member 80 may be attached to the fuselage, for example.

[0091] (6-3) Modification C In the above embodiment, the upper end H3 of the second layer L2 is located above the lower end H1 of the stator 51. However, this is not limitative. For example, the upper end H3 of the second layer L2 may be located below the lower end H1 of the stator 51, as shown in FIG. 7 .

[0092] (6-4) Modification D The partition member 80 may have a three-dimensional shape, for example, as shown in FIG. 8 . In this case, the partition member 80 has a flat portion 83 and a wall portion 84. The flat portion 83 is an annular plate material. The wall portion 84 is provided integrally with the flat portion 83. The wall portion 84 is annular and extends upward from the inner periphery of the flat portion 83. The upper end of the wall portion 84 is positioned so as to fit into the inner periphery of the coil 51 a of the stator 51. The outer diameter of the wall portion 84 is larger than the inner diameter of the stator 51.

[0093] In the modification D, the lower end H1 of the partition member 80 is the lower end of the flat portion 83 .

[0094] (6-5) Modification E In the above embodiment, the outer peripheral surface of the partition member 80 extends to a position where it abuts against the inner peripheral surface of the casing 20, but this is not limiting. For example, taking into consideration dimensional errors of the partition member 80 and ease of assembly, a small gap may be provided between the outer peripheral surface of the partition member 80 and the inner peripheral surface of the casing 20.

[0095] (6-6) Modification F In the above embodiment, only PAG oil is used as the refrigerating machine oil, but this is not particularly limited. The refrigerating machine oil may be a mixture of PAG oil and other oils. For example, the refrigerating machine oil may be a mixture of PAG oil and polyoxyethylene (POE) oil. In this case, the POE oil content is preferably 40 to 80 mass%.

[0096] Although the embodiments of the present disclosure have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the present disclosure as defined in the claims.

[0097] INDUSTRIAL APPLICABILITY As described above, the present disclosure is useful for compressors and refrigeration devices.

[0098] 10: Compressor 20: Casing 30: Compression mechanism 40: Drive shaft 50: Motor 51: Stator 80: Partition member 100: Refrigeration device 100a: Refrigerant circuit L1: First layer L2: Second layer

[0099] JP 2024-13789 A

Claims

1. A compressor comprising: a casing (20) for storing refrigeration oil; a compression mechanism (30) for compressing a refrigerant contained inside the casing; a drive shaft (40) for driving the compression mechanism; a motor (50) having a stator (51) for rotating the drive shaft; and a partition member (80) disposed below the motor and separating a side closer to the motor from a side farther from the motor, wherein the refrigeration oil mixed with the refrigerant inside the casing separates into a first layer (L1) and a second layer (L2) located above the first layer when the compressor is stopped, and a lower end (H1) of the partition member is located above an upper end (H2) of the first layer.

2. The compressor according to claim 1, wherein the height of the lower end of the partition member is located below the height of the oil surface of the second layer.

3. The compressor according to claim 1 or 2, wherein the refrigeration oil is an incompatible oil that is incompatible with the refrigerant.

4. The compressor according to claim 3, wherein the refrigeration oil contains any one of polyalkylene glycol, polyvinyl ether, and polyol ester.

5. The compressor according to claim 4, wherein the refrigeration oil is a mono-ol type polyalkylene glycol.

6. The compressor according to any one of claims 1 to 5, wherein the liquid density of the first layer, calculated by dividing the mass of the mixed liquid of the refrigerant and the refrigeration oil by the volume, is greater than the liquid density of the second layer.

7. The compressor according to any one of claims 1 to 6, wherein the concentration of the refrigerating machine oil in the first layer is greater than the concentration of the refrigerating machine oil in the second layer.

8. A compressor according to any one of claims 1 to 7, wherein the refrigerant is a natural refrigerant.

9. The compressor according to claim 8, wherein the refrigerant is a single refrigerant made of hydrocarbon or a mixed refrigerant containing hydrocarbon.

10. The compressor of claim 9, wherein the refrigerant is propane.

11. A refrigeration device comprising the compressor according to any one of claims 1 to 10.

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