Compressor, refrigeration device, and refrigerator oil

Abstract

To provide a compressor in which deterioration due to hydrolysis of an insulating member is sufficiently suppressed, and decrease of reliability is suppressed.SOLUTION: A compressor 11 comprises: a casing 50; a compression mechanism 20; and an insulating film 86c. A refrigerator oil is retained in the casing 50. The compression mechanism 20 is installed in the casing 50 and compresses a refrigerant. The insulating film 86c is contained within the casing 50 and is formed of a polymer having an ester bond. The refrigerant is mainly composed of a hydrocarbon. A saturation moisture content of the refrigerant is less than 0.3 wt.%. A saturation moisture content of the refrigerator oil is 1.8 wt.% or more.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a compressor, a refrigeration device, and a refrigeration oil. [Background technology]

[0002] Patent Document 1 (WO 2009 / 072314) describes a compressor that uses R290 (propane) as a refrigerant. Summary of the Invention [Problem to be solved by the invention]

[0003] Hydrocarbon refrigerants such as R290 have a lower saturated water content than HFC refrigerants such as R410A. Therefore, in compressors using hydrocarbon refrigerants, the insulating materials inside the compressor may deteriorate due to the moisture inside the compressor, which may cause a short circuit inside the compressor. [Means for solving the problem]

[0004] A compressor according to a first aspect includes a casing, a compression mechanism, and an insulating member. Refrigeration oil is stored in the casing. The compression mechanism is housed within the casing and compresses a refrigerant. The insulating member is housed within the casing and is made of a polymer having an ester bond. The refrigerant is mainly composed of hydrocarbon. The refrigerant has a saturated moisture content of less than 0.3% by weight. The refrigeration oil has a saturated moisture content of 1.8% by weight or more.

[0005] In this compressor, even if the saturated moisture content of the refrigerant is low, the saturated moisture content of the refrigeration oil is high enough to sufficiently suppress deterioration of the insulating members due to hydrolysis, thereby suppressing a decrease in the reliability of the compressor.

[0006] A compressor according to a second aspect is the compressor according to the first aspect, wherein the refrigeration oil is selected from the group consisting of polyalkylene glycol, a mixed oil of polyalkylene glycol and polyol ester, a mixed oil of polyalkylene glycol and polyvinyl ether, a mixed oil of polyalkylene glycol and alkylbenzene, and a mixed oil of polyalkylene glycol and mineral oil.

[0007] In this compressor, even if the saturated moisture content of the refrigerant is low, the saturated moisture content of the refrigeration oil is high enough to sufficiently suppress deterioration of the insulating members due to hydrolysis, thereby suppressing a decrease in the reliability of the compressor.

[0008] A compressor according to a third aspect is the compressor according to the first or second aspect, in which the refrigerant is propane or isobutane.

[0009] In this compressor, even if the saturated moisture content of the refrigerant is low, the saturated moisture content of the refrigeration oil is high enough to sufficiently suppress deterioration of the insulating members due to hydrolysis, thereby suppressing a decrease in the reliability of the compressor.

[0010] A compressor according to a fourth aspect is the compressor according to any one of the first to third aspects, in which the polymer is selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate.

[0011] This compressor includes an insulating member made of a polymer that is not easily deteriorated by hydrolysis, so that deterioration of the reliability of the compressor is suppressed.

[0012] A compressor according to a fifth aspect is the compressor according to any one of the first to fourth aspects, further comprising a motor. The motor is connected to the compression mechanism and drives the compression mechanism. The insulating member is an insulating film attached to the motor for suppressing the occurrence of an inter-phase short circuit of the motor.

[0013] In this compressor, the insulating film is less susceptible to degradation due to hydrolysis, so the occurrence of short circuits in the compressor is suppressed, and therefore deterioration in the reliability of the compressor is suppressed.

[0014] A refrigeration apparatus according to a sixth aspect includes the compressor according to any one of the first to fifth aspects.

[0015] In this refrigeration apparatus, deterioration of the insulating members of the compressor due to hydrolysis is sufficiently suppressed, so that deterioration of the reliability of the refrigeration apparatus is suppressed.

[0016] A refrigeration oil according to a seventh aspect is a refrigeration oil used in a compressor including a compression mechanism for compressing a refrigerant mainly composed of a hydrocarbon, and an insulating member made of a polymer having an ester bond. The refrigeration oil is selected from the group consisting of polyalkylene glycol, a mixed oil of polyalkylene glycol and polyol ester, a mixed oil of polyalkylene glycol and polyvinyl ether, a mixed oil of polyalkylene glycol and alkylbenzene, and a mixed oil of polyalkylene glycol and mineral oil. The saturated water content of the refrigeration oil is 1.8% by weight or more.

[0017] Even when this refrigeration oil is used in a compressor that compresses a refrigerant with a low saturated water content, the saturated water content is high enough to sufficiently suppress deterioration due to hydrolysis of the compressor's insulating components, thereby suppressing a decrease in the compressor's reliability. [Brief description of the drawings]

[0018] [Figure 1] 1 is a schematic configuration diagram of an air conditioning device 1. FIG. [Diagram 2] 1 is a block diagram of an air conditioning device 1. FIG. [Diagram 3] FIG. 2 is a schematic cross-sectional view of a compressor 11. [Figure 4] 2 is an enlarged view of the floating member 30 of the compressor 11 and its surroundings. FIG. [Diagram 5] FIG. 2 is a top view of a stator 70a of a motor 70. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] An air conditioner 1, which is an example of a refrigeration device equipped with a compressor according to an embodiment of the present disclosure, will be described with reference to the drawings.

[0020] (1) Air conditioning unit 1 The air conditioner 1 conditions the air in a target space by performing a vapor compression refrigeration cycle. As shown in Fig. 1, the air conditioner 1 mainly has an outdoor unit 2, an indoor unit 3, a gas refrigerant connection pipe 5, a liquid refrigerant connection pipe 6, a controller 7, and a remote control 8. The gas refrigerant connection pipe 5 and the liquid refrigerant connection pipe 6 connect the outdoor unit 2 and the indoor unit 3.

[0021] In the air conditioner 1, a refrigeration cycle is repeatedly performed in which the refrigerant sealed in the refrigerant circuit 10 is compressed, condensed (radiates heat), reduced in pressure, evaporated (absorbs heat), and then compressed again.

[0022] The refrigerant circuit 10 is filled with a refrigerant for performing a vapor compression refrigeration cycle. The refrigerant filled in the refrigerant circuit 10 is a simple refrigerant consisting of only a hydrocarbon-based refrigerant, or a mixed refrigerant containing a hydrocarbon-based refrigerant and another refrigerant. The mixed refrigerant is a refrigerant containing a hydrocarbon-based refrigerant as a main component. The content of the hydrocarbon-based refrigerant in the mixed refrigerant is 50% by weight or more. The mixed refrigerant may contain multiple types of hydrocarbon-based refrigerants. The hydrocarbon-based refrigerant is selected from the group consisting of methane (R50), ethane (R170), propane (R290), butane (R600), isobutane (R600a), pentane (R601), isopentane (R601a), ethylene (R1150), propylene (R1270), and cyclopropane (RC270). The hydrocarbon-based refrigerant is preferably propane (R290) or isobutane (R600a). Hydrocarbon refrigerants such as R290 have a lower saturated water content than HFC refrigerants such as R410A. In this embodiment, the saturated water content of the refrigerant charged into the refrigerant circuit 10 is less than 0.3% by weight. The saturated water content of the refrigerant may be less than 0.15% by weight.

[0023] In the refrigerant circuit 10, refrigerating machine oil is sealed together with the refrigerant. The refrigerating machine oil is used to lubricate sliding parts in the refrigerant circuit 10. The refrigerating machine oil is selected from the group consisting of polyalkylene glycol, a mixed oil of polyalkylene glycol and polyol ester, a mixed oil of polyalkylene glycol and polyvinyl ether, a mixed oil of polyalkylene glycol and alkylbenzene, and a mixed oil of polyalkylene glycol and mineral oil. One type of refrigerating machine oil may be used alone, or two or more types may be used in combination. The saturated water content of the refrigerating machine oil is 1.8% by weight or more, preferably 3.5% by weight or more, and more preferably 10% by weight or more.

[0024] The refrigerating machine oil preferably contains at least one additive selected from the group consisting of an extreme pressure agent, an acid scavenger, and an antioxidant. These additives are preferably blended in an amount of, for example, 5.0% by weight or less in the refrigerating machine oil.

[0025] Examples of the extreme pressure agents include extreme pressure agents containing phosphate esters; extreme pressure agents based on organic sulfur compounds such as monosulfides, polysulfides, sulfoxides, sulfones, thiosulfinates, sulfurized oils and fats, thiocarbonates, thiophenes, thiazoles, and methanesulfonic acid esters; extreme pressure agents based on thiophosphate esters such as thiophosphate triesters; extreme pressure agents based on esters such as higher fatty acids, hydroxyaryl fatty acids, polyhydric alcohol esters, and acrylic acid esters; and chlorinated hydrocarbons such as chlorinated paraffins. organic chlorine-based extreme pressure agents such as chlorinated carboxylic acid derivatives; organic fluorinated extreme pressure agents such as fluorinated aliphatic carboxylic acids, fluorinated ethylene resins, fluorinated alkyl polysiloxanes, and fluorinated graphite; alcohol-based extreme pressure agents such as higher alcohols; and metal compound-based extreme pressure agents such as naphthenates (lead naphthenate, etc.), fatty acid salts (lead fatty acid, etc.), thiophosphates (zinc dialkyldithiophosphate, etc.), thiocarbamate, organic molybdenum compounds, organic tin compounds, organic germanium compounds, and boric acid esters.

[0026] Examples of the acid scavenger include phenyl glycidyl ether, alkyl glycidyl ether, alkylene glycol glycidyl ether, cyclohexene oxide, α-olefin oxide, epoxy compounds such as epoxidized soybean oil, and carbodiimides. Among these, from the viewpoint of compatibility with refrigerating machine oil, phenyl glycidyl ether, alkyl glycidyl ether, alkylene glycol glycidyl ether, cyclohexene oxide, and α-olefin oxide are preferred. The number of carbon atoms of these acid scavengers is preferably 3 to 30, and more preferably 4 to 24. The number of carbon atoms of α-olefin oxide is preferably 4 to 50, and more preferably 4 to 24. The acid scavenger may be used alone or in combination of two or more.

[0027] Examples of the antioxidant include phenol-based antioxidants and amine-based antioxidants. Examples of the phenol-based antioxidants include 2,6-di-tert-butyl-4-methylphenol (DBPC), 2,6-di-tert-butyl-4-ethylphenol, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,4-dimethyl-6-tert-butylphenol, 2,6-di-tert-butylphenol, di-tert-butyl-p-cresol, and bisphenol A. Examples of the amine-based antioxidants include N,N'-diisopropyl-p-phenylenediamine, N,N'-di-sec-butyl-p-phenylenediamine, phenyl-α-naphthylamine, N,N'-di-phenyl-p-phenylenediamine, and N,N-di(2-naphthyl)-p-phenylenediamine.

[0028] (1-1) Outdoor unit 2 The outdoor unit 2 is connected to the indoor unit 3 via a gas refrigerant connection pipe 5 and a liquid refrigerant connection pipe 6, and constitutes a part of a refrigerant circuit 10. The outdoor unit 2 mainly has a compressor 11, a four-way switching valve 12, an outdoor heat exchanger 13, an expansion valve 9, a low-pressure receiver 14, an outdoor fan 15, a gas-side shut-off valve 16, and a liquid-side shut-off valve 17.

[0029] The compressor 11 is a device that compresses a low-pressure refrigerant in a refrigeration cycle to a high pressure. The compressor 11 changes the volume of a compression chamber by rotating a compression element such as a rotary type or scroll type by a compressor motor, thereby compressing the refrigerant in the compression chamber. The operating frequency of the compressor motor can be controlled by an inverter.

[0030] The four-way switching valve 12 switches between a first connection state (solid lines in FIG. 1) and a second connection state (dotted lines in FIG. 1) by switching the connection state of the refrigerant circuit 10. The first connection state connects the discharge side of the compressor 11 to the outdoor heat exchanger 13, and also connects the suction side of the compressor 11 to the gas side shut-off valve 16. The second connection state connects the discharge side of the compressor 11 to the gas side shut-off valve 16, and also connects the suction side of the compressor 11 to the outdoor heat exchanger 13. The four-way switching valve 12 has four connection ports.

[0031] The outdoor heat exchanger 13 functions as a condenser or radiator of high-pressure refrigerant in the refrigeration cycle during cooling operation, and functions as an evaporator or heat absorber of low-pressure refrigerant in the refrigeration cycle during heating operation. The outdoor heat exchanger 13 has a plurality of heat transfer tubes (not shown) through which refrigerant flows, and a plurality of heat transfer fins (not shown) through which air flows through the gaps between them. The plurality of heat transfer tubes are lined up in the vertical direction, and each heat transfer tube extends substantially horizontally. The material of the heat transfer tubes is, for example, copper, copper alloy (brass, etc.), and stainless steel (SUS304, etc.). The plurality of heat transfer fins extending in the vertical direction are lined up along the direction in which the heat transfer tubes extend, with a predetermined interval between each other. The plurality of heat transfer fins and the plurality of heat transfer tubes are combined so that the plurality of heat transfer tubes penetrate each heat transfer fin.

[0032] The outdoor fan 15 supplies outdoor air to the outdoor heat exchanger 13, exchanges heat with the refrigerant in the outdoor heat exchanger 13, and generates an airflow to be discharged outside the outdoor unit 2. The outdoor fan 15 is rotationally driven by an outdoor fan motor.

[0033] The expansion valve 9 is provided between the liquid side end of the outdoor heat exchanger 13 and the liquid side stop valve 17. The expansion valve 9 is, for example, an electronic expansion valve whose valve opening degree can be adjusted by electronic control.

[0034] The low-pressure receiver 14 is provided between the suction side of the compressor 11 and one of the four connection ports of the four-way switching valve 12. The low-pressure receiver 14 is a refrigerant container capable of storing surplus refrigerant in the refrigerant circuit 10 as liquid refrigerant.

[0035] The gas-side shutoff valve 16 is a manual valve provided in the outdoor unit 2 at a connection portion with the gas refrigerant communication pipe 5.

[0036] The liquid-side shutoff valve 17 is a manual valve provided in the outdoor unit 2 at a connection portion with the liquid refrigerant connection pipe 6.

[0037] The outdoor unit 2 has an outdoor unit control section 71 that controls the operation of each section constituting the outdoor unit 2. The outdoor unit control section 71 has a microcomputer including a CPU, memory, etc. The outdoor unit control section 71 is connected to the indoor unit control sections 72 of each indoor unit 3 via communication lines, and transmits and receives control signals, etc.

[0038] As shown in FIG. 1, the outdoor unit 2 is provided with a discharge temperature sensor 75, an intake temperature sensor 76, an outdoor heat exchanger temperature sensor 77, an outdoor air temperature sensor 78, and the like. These sensors are electrically connected to the outdoor unit control unit 71 and transmit detection signals to the outdoor unit control unit 71. The discharge temperature sensor 75 detects the temperature of the refrigerant flowing through the discharge pipe 4d connecting the discharge side of the compressor 11 and one of the four connection ports of the four-way switching valve 12. The intake temperature sensor 76 detects the temperature of the refrigerant flowing through the intake pipe 4e extending from the low pressure receiver 14 to the intake side of the compressor 11, among the intake passages connecting the intake side of the compressor 11 and one of the four connection ports of the four-way switching valve 12. The outdoor heat exchanger temperature sensor 77 detects the temperature of the refrigerant flowing through the pipe near the liquid side end of the outdoor heat exchanger 13. The outdoor air temperature sensor 78 detects the temperature of the outdoor air before passing through the outdoor heat exchanger 13.

[0039] (1-2) Indoor unit 3 The indoor unit 3 is installed on the walls and ceiling of the room, which is the target space. The indoor unit 3 is connected to the outdoor unit 2 via a gas refrigerant connection pipe 5 and a liquid refrigerant connection pipe 6, and constitutes a part of the refrigerant circuit 10. The indoor unit 3 mainly has an indoor heat exchanger 18 and an indoor fan 19.

[0040] The liquid side end of the indoor heat exchanger 18 is connected to the liquid refrigerant connection pipe 6. The gas side end of the indoor heat exchanger 18 is connected to the gas refrigerant connection pipe 5. The indoor heat exchanger 18 functions as an evaporator or heat absorber of low-pressure refrigerant in the refrigeration cycle during cooling operation, and functions as a condenser or radiator of high-pressure refrigerant in the refrigeration cycle during heating operation. Similar to the outdoor heat exchanger 13, the indoor heat exchanger 18 has a plurality of heat transfer tubes (not shown) through which refrigerant flows, and a plurality of heat transfer fins (not shown) through which air flows between the gaps between them.

[0041] The indoor fan 19 draws in air from the room, which is the target space, exchanges heat with the refrigerant in the indoor heat exchanger 18, and then generates an airflow to be discharged to the outside of the indoor unit 3. The indoor fan 19 is rotationally driven by an indoor fan motor.

[0042] The indoor unit 3 has an indoor unit control unit 72 that controls the operation of each part that constitutes the indoor unit 3. The indoor unit control unit 72 has a microcomputer including a CPU, memory, etc. The indoor unit control unit 72 is connected to the outdoor unit control unit 71 via a communication line and transmits and receives control signals, etc.

[0043] 1, the indoor unit 3 is provided with an indoor heat exchanger temperature sensor 73, an indoor air temperature sensor 74, etc. These sensors are electrically connected to the indoor unit control unit 72 and transmit detection signals to the indoor unit control unit 72. The indoor heat exchanger temperature sensor 73 detects the temperature of the refrigerant flowing through the piping near the liquid side end of the indoor heat exchanger 18. The indoor air temperature sensor 74 detects the temperature of the indoor air before it passes through the indoor heat exchanger 18.

[0044] (1-3) Controller 7 In the air conditioner 1, an outdoor unit control section 71 and an indoor unit control section 72 are connected via a communication line to constitute a controller 7 that controls the operation of the air conditioner 1. The controller 7 mainly has a CPU and memories such as ROM and RAM. Various processes and controls by the controller 7 are realized by the integrated functioning of each section included in the outdoor unit control section 71 and the indoor unit control section 72.

[0045] 2 via the outdoor unit control unit 71 and the indoor unit control unit 72. The controller 7 controls the components of the refrigerant circuit 10 so that, for example, the temperature of the fluid (refrigerant and refrigeration oil) flowing through the refrigerant circuit 10 of the air conditioner 1 is kept below a predetermined temperature. Examples of such control include control to prevent the drive frequency of the compressor 11 from exceeding a predetermined value, control to prevent the temperature of the refrigerant discharged from the compressor 11 from exceeding a predetermined temperature, and control to prevent the pressure of the refrigerant discharged from the compressor 11 from exceeding a predetermined pressure.

[0046] (1-4) Remote Control 8 The remote control 8 is installed in a room which is the target space, or in a specific space of a building which includes the target space, and is used by a user or the like to issue operation control commands for the air conditioner 1 and to monitor the operating status.

[0047] The remote control 8 includes a reception unit 8a such as operation buttons and a touch panel, and a display 8b capable of displaying various information. The reception unit 8a receives input of various information by being operated by a user or the like. The remote control 8 is connected to the outdoor unit control unit 71 and the indoor unit control unit 72 via a communication line, and supplies information received by the reception unit 8a from a user or the like to the controller 7. The remote control 8 outputs information received from the controller 7 to the display 8b.

[0048] The information received by the reception unit 8a from the user, etc., is not particularly limited, but includes a command to execute the cooling operation mode, a command to execute the heating operation mode, a command to stop the operation, and information regarding a designation to set a temperature, etc. The information displayed on the display 8b is not particularly limited, but includes the current operation mode (cooling or heating operation mode), the set temperature, and information indicating the occurrence of various abnormalities, etc.

[0049] (2) Compressor 11 The compressor 11 is a so-called low-pressure dome-type scroll compressor. As shown in Fig. 3, the compressor 11 mainly includes a casing 50, a compression mechanism 20, a floating member 30, a housing 40, a seal member 60, a motor 70, a crankshaft 80, and a lower bearing housing 90.

[0050] (2-1) Casing 50 The casing 50 has a substantially cylindrical member 50a, an upper lid 50b attached to the upper end of the cylindrical member 50a, and a lower lid 50c attached to the lower end of the cylindrical member 50a. The cylindrical member 50a, the upper lid 50b, and the lower lid 50c are fixed by welding so as to maintain airtightness. The casing 50 accommodates components of the compressor 11, including the compression mechanism 20, the floating member 30, the housing 40, the seal member 60, the motor 70, the crankshaft 80, and the lower bearing housing 90.

[0051] The compression mechanism 20 is installed on the upper part of the casing 50. The floating member 30 and the housing 40 are installed below the compression mechanism 20. The motor 70 is installed below the housing 40. The lower bearing housing 90 is installed below the motor 70.

[0052] An oil reservoir space 11a is formed at the bottom of the casing 50. Refrigeration oil for lubricating the compression mechanism 20 and the like is stored in the oil reservoir space 11a. The casing 50 has an oil reservoir 50d that forms the oil reservoir space 11a. The oil reservoir 50d is a part of the casing 50, and corresponds to a portion below the lower bearing housing 90. For example, as shown in FIG. 3, the oil reservoir 50d is composed of a lower cover 50c and the lower end of the cylindrical member 50a. An oil reservoir temperature sensor 79 is attached to the outer surface of the oil reservoir 50d. The oil reservoir temperature sensor 79 measures the temperature of the oil reservoir 50d.

[0053] The internal space of the casing 50 is divided into a first space S1 and a second space S2 by a partition plate 42. The first space S1 is the space below the partition plate 42. The second space S2 is the space above the partition plate 42. The partition plate 42 is fixed to the compression mechanism 20 and the casing 50 by welding so as to maintain airtightness between the first space S1 and the second space S2.

[0054] The partition plate 42 is a plate-like member formed in an annular shape in a plan view. The inner peripheral side of the partition plate 42 is fixed to the upper part of the fixed scroll 21 of the compression mechanism 20 over the entire circumference. The outer peripheral side of the partition plate 42 is fixed to the inner surface of the casing 50 over the entire circumference.

[0055] The first space S1 is a space in which the motor 70 is installed. The first space S1 is a space into which refrigerant flows from the refrigerant circuit 10 having the compressor 11 before being compressed by the compressor 11. The first space S1 is a space into which low-pressure refrigerant in a refrigeration cycle flows.

[0056] The second space S2 is a space into which the refrigerant discharged from the compression mechanism 20 (the refrigerant compressed by the compression mechanism 20) flows in. The second space S2 is a space into which high-pressure refrigerant in the refrigeration cycle flows in.

[0057] A suction pipe 51, a discharge pipe 52 and an injection pipe 53 are attached to the casing 50 so as to communicate between the inside and outside of the casing 50.

[0058] The suction pipe 51 is attached near the center of the casing 50 in the up-down direction (vertical direction). Specifically, as shown in Fig. 3, the suction pipe 51 is attached horizontally to the cylindrical member 50a at a height position between the housing 40 and the motor 70. The suction pipe 51 communicates between the outside of the casing 50 and a first space S1 inside the casing 50. The refrigerant before compression (low-pressure refrigerant in the refrigeration cycle) passes through the suction pipe 51 and flows into the first space S1.

[0059] The discharge pipe 52 is attached to the upper part of the casing 50 at a height position above the partition plate 42. Specifically, as shown in Fig. 3, the suction pipe 51 is attached horizontally to the upper lid 50b. The discharge pipe 52 communicates between the outside of the casing 50 and a second space S2 inside the casing 50. The refrigerant compressed by the compression mechanism 20 and flowing into the second space S2 (high-pressure refrigerant in the refrigeration cycle) passes through the discharge pipe 52 and flows out to the outside of the compressor 11.

[0060] The injection pipe 53 is attached to the upper part of the casing 50 at a height position lower than the partition plate 42. Specifically, as shown in FIG. 3, the injection pipe 53 is attached horizontally to the cylindrical member 50a at a height position of the compression mechanism 20. As shown in FIG. 3, the end of the injection pipe 53 on the inside side of the casing 50 is connected to the fixed scroll 21 of the compression mechanism 20. The injection pipe 53 communicates with the compression chamber Sc in the middle of compression inside the compression mechanism 20 through a passage (not shown) formed in the fixed scroll 21. An intermediate pressure refrigerant (a refrigerant with a pressure intermediate between low pressure and high pressure in the refrigeration cycle) is supplied to the compression chamber Sc in the middle of compression from the refrigerant circuit 10 having the compressor 11 through the injection pipe 53.

[0061] (2-2) Compression mechanism 20 The compression mechanism 20 mainly includes a fixed scroll 21 and a movable scroll 22. The fixed scroll 21 and the movable scroll 22 are combined with each other to form a compression chamber Sc. The compression mechanism 20 compresses the refrigerant in the compression chamber Sc and discharges the compressed refrigerant.

[0062] (2-2-1) Fixed Scroll 21 3, the fixed scroll 21 is mounted on a housing 40. The fixed scroll 21 and the housing 40 are fixed to each other by a fixing means such as a bolt.

[0063] The fixed scroll 21 has a disk-shaped fixed side end plate 21a, a spiral-shaped fixed side wrap 21b, and a peripheral portion 21c. The fixed side wrap 21b and the peripheral portion 21c extend from the front surface (lower surface) of the fixed side end plate 21a toward the movable scroll 22 side (downward). When the fixed scroll 21 is viewed from below, the fixed side wrap 21b is formed in a spiral shape (involute shape) from near the center of the fixed side end plate 21a toward the outer periphery. The peripheral portion 21c has a cylindrical shape. The peripheral portion 21c is located on the outer periphery side of the fixed side end plate 21a so as to surround the fixed side wrap 21b.

[0064] During operation of the compressor 11, the movable scroll 22 orbits relative to the fixed scroll 21, and the refrigerant (low-pressure refrigerant in the refrigeration cycle) that flows from the first space S1 into the compression chamber Sc on the periphery side is compressed as it moves to the innermost (center) compression chamber Sc. A discharge port 21d that discharges the refrigerant compressed in the compression chamber Sc is formed near the center of the fixed side end plate 21a by penetrating the fixed side end plate 21a in its thickness direction (up and down direction). The discharge port 21d is connected to the innermost compression chamber Sc. A discharge valve 23 that opens and closes the discharge port 21d is attached above the fixed side end plate 21a. When the pressure of the innermost compression chamber Sc that communicates with the discharge port 21d becomes higher than the pressure of the space above the discharge valve 23 (second space S2) by a predetermined value or more, the discharge valve 23 opens, and the refrigerant flows from the discharge port 21d to the second space S2.

[0065] A relief hole 21e is formed on the outer periphery of the discharge port 21d of the fixed side end plate 21a, penetrating the fixed side end plate 21a in the thickness direction. The relief hole 21e is connected to a compression chamber Sc formed on the outer periphery side of the innermost compression chamber Sc that is connected to the discharge port 21d. The relief hole 21e is connected to a compression chamber Sc in the middle of compression of the compression mechanism 20. A plurality of relief holes 21e may be formed in the fixed side end plate 21a. A relief valve 24 that opens and closes the relief hole 21e is attached above the fixed side end plate 21a. When the pressure of the compression chamber Sc that is connected to the relief hole 21e becomes higher than the pressure of the space (second space S2) above the relief valve 24 by a predetermined value or more, the relief valve 24, which is a safety valve, opens, and the refrigerant flows from the relief hole 21e to the second space S2.

[0066] (2-2-2) Movable Scroll 22 The movable scroll 22 has a disk-shaped movable side end plate 22a, a spiral movable side wrap 22b, and a cylindrical boss portion 22c. The movable side wrap 22b extends from the front surface (upper surface) of the movable side end plate 22a toward the fixed scroll 21 side (upward). The boss portion 22c extends from the back surface (lower surface) of the movable side end plate 22a toward the motor 70 side (downward). When the movable scroll 22 is viewed from above, the movable side wrap 22b is formed in a spiral shape (involute shape) from near the center of the movable side end plate 22a toward the outer periphery.

[0067] The fixed side wrap 21b of the fixed scroll 21 and the movable side wrap 22b of the movable scroll 22 are combined with each other to form a compression chamber Sc. The fixed scroll 21 and the movable scroll 22 are combined with each other so that the front surface (lower surface) of the fixed side end plate 21a faces the front surface (upper surface) of the movable side end plate 22a. This forms a compression chamber Sc surrounded by the fixed side end plate 21a, the fixed side wrap 21b, the movable side wrap 22b, and the movable side end plate 22a.

[0068] The compression mechanism 20 has a symmetric wrap structure or an asymmetric wrap structure. In the compression mechanism 20 having a symmetric wrap structure, a first compression chamber surrounded by the outer circumferential surface of the movable side wrap 22b and the inner circumferential surface of the fixed side wrap 21b, and a second compression chamber surrounded by the inner circumferential surface of the movable side wrap 22b and the outer circumferential surface of the fixed side wrap 21b are formed in point symmetry when viewed along the vertical direction. In the compression mechanism 20 having an asymmetric wrap structure, the first compression chamber and the second compression chamber are not formed in point symmetry when viewed along the vertical direction.

[0069] The movable side end plate 22a is disposed above the floating member 30. During operation of the compressor 11, the floating member 30 is pressed toward the movable scroll 22 by the pressure of the back pressure space Sb formed below the floating member 30. As a result, when the pressing portion 34 at the upper part of the floating member 30 comes into contact with the back surface (lower surface) of the movable side end plate 22a, the floating member 30 presses the movable scroll 22 toward the fixed scroll 21. The force of the floating member 30 pressing the movable scroll 22 toward the fixed scroll 21 causes the movable scroll 22 to be in close contact with the fixed scroll 21. As a result, leakage of refrigerant from a gap between the tooth tip (tip surface) of the fixed side wrap 21b and the bottom surface (main surface in contact with the tooth tip) of the movable side end plate 22a and a gap between the tooth tip of the movable side wrap 22b and the bottom surface of the fixed side end plate 21a is suppressed.

[0070] The back pressure space Sb is a space formed between the floating member 30 and the housing 40. As shown in FIG. 4, the back pressure space Sb is mainly formed on the back side (lower side) of the floating member 30. The refrigerant in the compression chamber Sc of the compression mechanism 20 is guided to the back pressure space Sb. The back pressure space Sb and the first space S1 around the back pressure space Sb are sealed. During operation of the compressor 11, the pressure in the back pressure space Sb is higher than the pressure in the first space S1.

[0071] An Oldham coupling 25 is disposed between the movable scroll 22 and the floating member 30. The Oldham coupling 25 slidably engages with both the movable scroll 22 and the floating member 30. The Oldham coupling 25 allows the movable scroll 22 to orbit relative to the fixed scroll 21 while suppressing rotation of the movable scroll 22 on its axis.

[0072] The boss portion 22c is disposed in an eccentric space 38 surrounded by the inner surface of the floating member 30. A first bearing metal 26 is disposed inside the boss portion 22c. The first bearing metal 26 is, for example, press-fitted and fixed inside the boss portion 22c. An eccentric portion 81 of a crankshaft 80 is inserted into the first bearing metal 26. By inserting the eccentric portion 81 into the first bearing metal 26, the movable scroll 22 and the crankshaft 80 are connected to each other.

[0073] (2-3) Floating member 30 The floating member 30 is disposed on the back side of the movable scroll 22 (the side opposite to the side on which the fixed scroll 21 is disposed). The floating member 30 is pressed toward the movable scroll 22 by the pressure in the back pressure space Sb, thereby pressing the movable scroll 22 toward the fixed scroll 21. A part of the floating member 30 also functions as a bearing that supports the crankshaft 80.

[0074] The floating member 30 mainly includes a cylindrical main body portion 30 a, a pressing portion 34 , and an upper bearing housing 31 .

[0075] The main body portion 30a defines an eccentric space 38 surrounded by the inner surface of the main body portion 30a. In the eccentric space 38, the boss portion 22c of the movable scroll 22 is disposed.

[0076] The pressing portion 34 is a cylindrical member extending from the upper end of the main body portion 30a toward the movable scroll 22. As shown in Fig. 4, a thrust surface 34a at the upper end of the pressing portion 34 faces the back surface of the movable end plate 22a of the movable scroll 22. The thrust surface 34a is formed in an annular shape in a plan view. When the floating member 30 is pressed toward the movable scroll 22 by the pressure of the back pressure space Sb, the thrust surface 34a comes into contact with the back surface of the movable end plate 22a and presses the movable scroll 22 toward the fixed scroll 21.

[0077] The upper bearing housing 31 is a cylindrical member disposed below the main body 30a (below the eccentric space 38). A second bearing metal 32 is disposed inside the upper bearing housing 31. The second bearing metal 32 is, for example, press-fitted and fixed inside the upper bearing housing 31. The second bearing metal 32 supports a main shaft 82 of the crankshaft 80 so as to be able to rotate freely.

[0078] (2-4) Housing 40 The housing 40 is a substantially cylindrical member disposed below the fixed scroll 21 and the floating member 30. The housing 40 supports the floating member 30. A back pressure space Sb is formed between the housing 40 and the floating member 30. The housing 40 is attached to the inner surface of the casing 50 by, for example, press fitting.

[0079] (2-5) Sealing member 60 The seal member 60 is a member for forming a back pressure space Sb between the floating member 30 and the housing 40. The seal member 60 is, for example, a gasket such as an O-ring. As shown in FIG. 4, the seal member 60 divides the back pressure space Sb into a first chamber B1 and a second chamber B2. The first chamber B1 and the second chamber B2 are spaces formed in a substantially annular shape in a plan view. The second chamber B2 is disposed inside the first chamber B1. In a plan view, the area of ​​the first chamber B1 is larger than the area of ​​the second chamber B2.

[0080] The first chamber B1 communicates with the compression chamber Sc in the middle of compression via a first flow path 64. The first flow path 64 is a flow path that guides the refrigerant in the middle of compression in the compression mechanism 20 (intermediate pressure refrigerant) to the first chamber B1. The first flow path 64 is formed in the fixed scroll 21 and the housing 40.

[0081] The second chamber B2 is in communication with the discharge port 21d of the fixed scroll 21 via a second flow passage 65. The second flow passage 65 is a flow passage that guides the refrigerant (high-pressure refrigerant) discharged from the compression mechanism 20 to the second chamber B2. The second flow passage 65 is formed in the fixed scroll 21 and the housing 40.

[0082] During operation of the compressor 11, the pressure in the second chamber B2 is higher than the pressure in the first chamber B1. However, since the area of ​​the first chamber B1 is larger than the area of ​​the second chamber B2 in a plan view, the pressing force of the movable scroll 22 against the fixed scroll 21 due to the pressure of the back pressure space Sb is unlikely to become excessive. Since the second chamber B2 is disposed on the inside of the first chamber B1, it is easy to ensure a balance between the force with which the movable scroll 22 is pressed downward by the pressure of the compression chamber Sc and the force with which the movable scroll 22 is pressed upward by the floating member 30.

[0083] (2-6) Motor 70 The motor 70 is a concentrated winding type motor housed inside the casing 50 and disposed below the compression mechanism 20. The motor 70 is mainly composed of a stator 70a fixed to the inner wall surface of the casing 50 and a rotor 70b rotatably housed inside the stator 70a. An air gap is provided between the stator 70a and the rotor 70b.

[0084] The stator 70a has a stator core 86 and a pair of insulators 87 attached to both vertical end faces of the stator core 86. As shown in Fig. 5, the stator core 86 has a cylindrical portion 86a and a plurality of teeth 86b protruding radially inward from the inner circumferential surface of the cylindrical portion 86a. A winding is wound around the teeth 86b of the stator core 86 together with the pair of insulators 87. As a result, a coil 88 is formed on each tooth 86b of the stator core 86.

[0085] The outer surface of the stator 70a is provided with a plurality of core cut portions (not shown) cut out at predetermined intervals in the circumferential direction from the upper end surface to the lower end surface of the stator 70a. The core cut portions form motor cooling passages extending vertically between the cylindrical member 50a of the casing 50 and the stator 70a.

[0086] The rotor 70b has a rotor core 89a made of multiple metal plates stacked in the vertical direction, and multiple magnets 89b embedded in the rotor core 89a. The magnets 89b are arranged at equal intervals along the circumferential direction of the rotor core 89a. The rotor 70b is connected to a crankshaft 80 that passes through its center of rotation in the vertical direction. The rotor 70b is connected to the movable scroll 22 of the compression mechanism 20 via the crankshaft 80. The motor 70 drives the movable scroll 22 by rotating the rotor 70b, causing the movable scroll 22 to orbit relative to the fixed scroll 21.

[0087] An insulating member is attached to the motor 70. In this embodiment, the insulating member is an insulating film 86c attached to the stator 70a in order to suppress the occurrence of an interphase short circuit in the motor 70. As shown in Fig. 5, the insulating film 86c is inserted into a space between adjacent teeth 86b in the circumferential direction so that windings of adjacent coils 88 in the circumferential direction of the rotor 70b do not come into contact with each other. The insulating film 86c may be supported by an insulator 87, for example.

[0088] The insulating member such as the insulating film 86c is formed from a resin made of a polymer having an ester bond, for example, selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate.

[0089] (2-7) Crankshaft 80 The crankshaft 80 connects the rotor 70b of the motor 70 and the movable scroll 22 of the compression mechanism 20. The crankshaft 80 extends in the vertical direction. The crankshaft 80 transmits the driving force of the motor 70 to the movable scroll 22.

[0090] The crankshaft 80 mainly includes an eccentric portion 81 and a main shaft 82 .

[0091] The eccentric portion 81 is disposed above the main shaft 82. The central axis of the eccentric portion 81 is eccentric with respect to the central axis of the main shaft 82. The eccentric portion 81 is connected to the first bearing metal 26 disposed inside the boss portion 22c of the movable scroll 22.

[0092] The main shaft 82 is rotatably supported by a second bearing metal 32 arranged in an upper bearing housing 31 of the floating member 30, and a third bearing metal 91 arranged in a lower bearing housing 90. The main shaft 82 is connected to the rotor 70b of the motor 70 between the upper bearing housing 31 and the lower bearing housing 90. The main shaft 82 extends in the vertical direction.

[0093] An oil passage (not shown) is formed inside the crankshaft 80. The oil passage has a main path and a branch path. The main path extends in the axial direction of the crankshaft 80 from the lower end to the upper end of the crankshaft 80. The branch path extends from the main path in the radial direction of the crankshaft 80. Refrigeration oil in the oil reservoir space 11a is pumped up by a pump (not shown) provided at the lower end of the crankshaft 80, and is supplied through the oil path to sliding parts between the crankshaft 80 and each of the first bearing metal 26, the second bearing metal 32, and the third bearing metal 91, sliding parts of the compression mechanism 20, etc.

[0094] (2-8) Lower bearing housing 90 The lower bearing housing 90 is fixed to the inner surface of the casing 50. The lower bearing housing 90 is disposed below the motor 70. A third bearing metal 91 is disposed inside the lower bearing housing 90. The third bearing metal 91 is, for example, press-fitted and fixed inside the lower bearing housing 90. The main shaft 82 of the crankshaft 80 passes through the third bearing metal 91. The third bearing metal 91 rotatably supports a lower side of the main shaft 82 of the crankshaft 80.

[0095] (3) Operation of Compressor 11 The operation of the compressor 11 in a normal state will be described below. The normal state is a state in which the pressure of the refrigerant discharged from the discharge port 21d of the compression mechanism 20 is higher than the pressure of the compression chamber Sc during compression.

[0096] When the motor 70 is driven, the rotor 70b rotates, and the crankshaft 80 connected to the rotor 70b also rotates. When the crankshaft 80 rotates, the movable scroll 22 orbits relative to the fixed scroll 21 without rotating on its axis due to the Oldham coupling 25. The low-pressure refrigerant that flows into the first space S1 from the suction pipe 51 passes through a refrigerant passage (not shown) formed in the housing 40 and is sucked into the compression chamber Sc on the peripheral side of the compression mechanism 20. When the movable scroll 22 orbits, the first space S1 and the compression chamber Sc are no longer in communication with each other, the volume of the compression chamber Sc decreases, and the pressure of the compression chamber Sc increases. An intermediate-pressure refrigerant is injected from the injection pipe 53 into the compression chamber Sc during compression. The pressure of the refrigerant increases as it moves from the compression chamber Sc on the peripheral side (outer side) to the compression chamber Sc on the central side (inner side), and finally becomes high pressure in the refrigeration cycle. The refrigerant compressed by the compression mechanism 20 is discharged from the discharge port 21d of the fixed side end plate 21a into the second space S2. The high-pressure refrigerant in the second space S2 is discharged from the discharge pipe 52.

[0097] (4) Features Moisture present in the refrigerant circuit 10 of the air conditioner 1 is absorbed by the refrigerant filled in the refrigerant circuit 10, the refrigerating machine oil sealed in the refrigerant circuit 10, and the insulating member (insulating film 86c, etc.) in the casing 50 of the compressor 11. The refrigerant, the refrigerating machine oil, and the insulating member can absorb moisture up to a weight corresponding to their respective saturated moisture contents. The saturated moisture content of the refrigerant is the ratio of the maximum weight of moisture that can be absorbed by the refrigerant to the weight of the refrigerant. The saturated moisture content of the refrigerating machine oil is the ratio of the maximum weight of moisture that can be absorbed by the refrigerating machine oil to the weight of the refrigerating machine oil. The saturated moisture content of the insulating member is the ratio of the maximum weight of moisture that can be absorbed by the insulating member to the weight of the insulating member. The saturated moisture content differs depending on the type and composition of the refrigerant, the refrigerating machine oil, and the insulating member. The unit of the saturated moisture content is weight % (wt%). The lower the saturated moisture content, the less moisture is absorbed.

[0098] The amount of moisture absorbed by the refrigerant, the refrigeration oil, and the insulating member in the refrigerant circuit 10 is distributed according to the ratio of the saturated moisture content of the refrigerant, the refrigeration oil, and the insulating member. Therefore, the lower the saturated moisture content of the refrigerant, the more likely the moisture in the refrigerant circuit 10 is absorbed by the insulating member. When moisture is absorbed by the insulating member, depending on the material of the insulating member, the insulating member may deteriorate due to the moisture. For example, if the insulating member is made of resin, the resin may be hydrolyzed by the moisture, causing the insulating member to deteriorate, and the insulating performance of the insulating member may decrease. If the insulating member is used to suppress the occurrence of an interphase short circuit of the motor 70, the deterioration of the insulating member may cause a short circuit inside the compressor 11. Therefore, the greater the amount of moisture absorbed by the insulating member, the greater the possibility that the insulating member attached to the motor 70 will deteriorate and cause a short circuit.

[0099] In this embodiment, the refrigerant mainly composed of hydrocarbons, which is filled in the refrigerant circuit 10 of the air conditioner 1, has a lower saturated water content than HFC refrigerants such as R410A. Specifically, the saturated water content of the refrigerant filled in the refrigerant circuit 10 is less than 0.3% by weight. However, the refrigerant oil filled in the refrigerant circuit 10 has a higher saturated water content than known refrigerant oils (polyvinyl ether, polyol ester, mineral oil, etc.). Specifically, the saturated water content of the refrigerant oil filled in the refrigerant circuit 10 is 1.8% by weight or more. In this way, the refrigerant circuit 10 uses a refrigerant with a low saturated water content and a refrigerant oil with a high saturated water content. Therefore, in this embodiment, the moisture in the refrigerant circuit 10 is easily absorbed by the refrigerant oil, so the amount of moisture absorbed by the insulating members in the casing 50 is reduced. Therefore, deterioration of the insulating members due to hydrolysis is suppressed, and the occurrence of a short circuit inside the motor 70 is suppressed.

[0100] (5) Examples The test results of the refrigeration system in this embodiment will be described. In the test of the refrigeration system, the air conditioner 1 using the refrigerant and refrigeration oil was operated for a long time, and the change in strength of the insulating member in the casing 50 of the compressor 11 was measured. The conditions for the long-term operation of the air conditioner 1 are as follows. Test time: 2000 hours ·Discharge temperature: 130℃ Discharge pressure (refrigerant is CO 2 (For 12MPa) Discharge pressure (refrigerant is CO 2 Other than above): Discharge pressure equivalent to condensation temperature of 65°C The test time is the continuous operation time of the air conditioner 1 in the test of the refrigeration unit. The discharge temperature is the temperature of the compressed refrigerant gas discharged from the compressor 11. The discharge pressure is the pressure of the compressed refrigerant gas discharged from the compressor 11.

[0101] When the air conditioner 1 is operated for a long time, the tensile strength of the insulating member gradually decreases. In this test, the deterioration time was measured, which is the time required for the tensile strength of the insulating member to decrease by 50% of the initial tensile strength of the insulating member. The initial tensile strength of the insulating member is the tensile strength in an unused state before being attached to the motor 70 of the compressor 11. The following table shows the test results. [Table 1]

[0102] The refrigerants used in the test were R290 (propane), R410A (a 1:1 mixture of R32 and R125), R32 (difluoromethane), and CO. 2 (carbon dioxide).

[0103] The refrigeration oils used in the tests were PAG (polyalkylene glycol), PVE (polyvinyl ether), POE (polyol ester), and mineral oil. The PAG used in Example 1 was a polymer of PO (propylene oxide). The PAG used in Example 2 was a copolymer of PO (propylene oxide) and EO (ethylene oxide). The PAG used in Example 3 was a polymer of diol-type monomers such as ethylene glycol and propylene glycol.

[0104] The insulating member is molded from a resin made of a polymer having an ester bond. The insulating member is an insulating film 86c molded from polyethylene terephthalate. Regarding the criteria for judging deterioration of the insulating member, when the deterioration time exceeds 20,000 hours, it is judged that the deterioration of the insulating member is suppressed, and when it is 20,000 hours or less, it is judged that the deterioration of the insulating member is not suppressed and deterioration is confirmed. The standard of 20,000 hours is a value set based on the deterioration time of 21,260 hours in Comparative Example 1.

[0105] The refrigerants used were R290, which has a low saturated water content, and R410A, R32, and CO, which have a high saturated water content. 2 Refrigerants with high saturated water content (R410A, R32 and CO 2 When a refrigerant with a low saturated moisture content (R290) was used, the amount of moisture distributed to the insulating members was small, and therefore deterioration of the insulating members was suppressed regardless of the type of refrigerant oil (Comparative Examples 1 to 3). When a refrigerant with a low saturated moisture content (R290) was used, deterioration of the insulating members was suppressed when a refrigerant oil with a saturated moisture content of 1.8% by weight or more was used (Examples 1 to 3), and deterioration of the insulating members was confirmed when a refrigerant oil with a saturated moisture content of less than 1.8% by weight was used (Comparative Examples 4 to 6).

[0106] From the above test results, R410A, R32 and CO 2 It was confirmed that even if a refrigerant such as R290, which has a lower saturated moisture content than R290, is used, by using a refrigeration oil with a saturated moisture content of 1.8% by weight or more, the amount of moisture distributed to the insulating components is reduced, and deterioration of the insulating components is suppressed.

[0107] (6) Variations (6-1) Variation A In the air conditioner 1 of the embodiment, the compressor 11 is a low-pressure dome-type scroll compressor. However, the compressor 11 may be a high-pressure dome-type compressor. In a high-pressure dome-type compressor, the low-pressure refrigerant flowing through the refrigerant circuit 10 is directly sucked into the compression chamber Sc on the peripheral side of the compression mechanism 20 without flowing into the internal space of the casing 50. Then, the high-pressure refrigerant discharged from the compression mechanism 20 flows into the internal space of the casing 50 and is then discharged from the compressor 11. Therefore, during operation of the high-pressure dome-type compressor, the internal space of the casing 50 is in a high-pressure state.

[0108] Additionally, the compressor 11 may be a type of compressor other than a scroll compressor, such as a rotary compressor.

[0109] (6-2) Variation B In the embodiment, the insulating member attached to the motor 70 is an insulating film 86c. However, the insulating member may be a member other than the insulating film 86c as long as it is a member molded from a resin made of a polymer having an ester bond. For example, the insulating member may be an insulating coating of the winding of the coil 88, a tie string, an insulating sleeve, an insulating tube, an insulating cap, an insulator 87, and a cluster block. The tie string is a member for fixing the lead wires extending from the coils 88 of each phase to the stator 70a. The insulating sleeve is a braided wire for protecting the lead wires extending from the coils 88 of each phase. The insulating tube is a member for bundling the lead wires extending from the coils 88 of each phase. The insulating cap is a member for protecting the neutral point of the coils 88 in the concentrated winding type motor 70. The cluster block is a member for protecting the power terminal connected to the coils 88.

[0110] The material of the insulating coating of the winding of the coil 88 is, for example, polyesterimide-amideimide. The material of the tie string, insulating sleeve, insulating tube, and insulating cap is, for example, polyethylene terephthalate. The material of the insulator 87 is, for example, liquid crystal polymer (aromatic polyester resin)-polyphenylene sulfide. The material of the cluster block is, for example, polybutylene terephthalate.

[0111] (6-3) Variation C In the embodiment, the motor 70 is a concentrated winding type motor. However, the motor 70 may be a distributed winding type motor.

[0112] (6-4) Variation D In the embodiment, the refrigeration device including the compressor 11 is an air conditioner 1. However, the refrigeration device may be a device other than the air conditioner 1 that performs a refrigeration cycle.

[0113] -Conclusion- 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 described in the claims. [Explanation of symbols]

[0114] 1: Air conditioning equipment (refrigeration equipment) 11: Compressor 20: Compression mechanism 50: Casing 70: Motor 86c: Insulating film (insulating material) [Prior art documents] [Patent documents]

[0115] [Patent Document 1] International Publication No. 2009 / 072314

Claims

1. A low-pressure dome type rotary compressor, A casing (50) in which refrigeration oil is stored; a compression mechanism (20) housed in the casing and compressing a refrigerant; an insulating member housed in the casing and made of a polymer having an ester bond; Equipped with The refrigerant is mainly composed of a hydrocarbon, The refrigerant has a saturated water content of less than 0.15% by weight, The saturated water content of the refrigerating machine oil is 1.8% by weight or more, The refrigeration oil is selected from the group consisting of polyalkylene glycol, a mixed oil of polyalkylene glycol and polyol ester, a mixed oil of polyalkylene glycol and polyvinyl ether, a mixed oil of polyalkylene glycol and alkylbenzene, and a mixed oil of polyalkylene glycol and mineral oil. Compressor (11).

2. The refrigerant is propane or isobutane. The compressor according to claim 1.

3. The polymer is selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate. The compressor according to claim 1 or 2.

4. The refrigeration oil is a polyalkylene glycol, The polyalkylene glycol is selected from the group consisting of polymers of propylene oxide, copolymers of propylene oxide and ethylene oxide, and polymers of ethylene glycol and propylene glycol. The compressor according to any one of claims 1 to 3.

5. A motor (70) is connected to the compression mechanism and drives the compression mechanism, The insulating member is an insulating film (86c) attached to the motor to suppress the occurrence of an interphase short circuit of the motor. A compressor according to any one of claims 1 to 4.

6. A compressor according to any one of claims 1 to 5, Refrigeration device (1).

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