Compressor and refrigeration apparatus

Abstract

When using refrigerating machine oil which is separated into two layers in a mixture with a refrigerant under a prescribed condition, a mixture of a layer having a higher refrigerant concentration is supplied to a sliding portion, and consequently, the reliability of a compressor deteriorates. A scroll compressor (101) is provided with a casing (10), a compression mechanism (15), a motor (16), and a housing (23). The housing (23) has an annular groove (23g), a first oil supply passage (23c), and a second oil supply passage (23d). The annular groove (23g) is the supply source of refrigerating machine oil that is supplied to a sliding portion in the casing (10). The first oil supply passage (23c) is linked with the sliding portion. The second oil supply passage (23d) is linked with the annular groove (23g) via a first opening (23e), and is linked with the first oil supply passage (23c) via a second opening (23f). In the annular groove (23g), the refrigerating machine oil mixed with a refrigerant is separated, in a first state, into a first layer (L1) and a second layer (L2) above the first layer (L1). A first height position (H1) of the upper end of the first opening (23e) is lower than a second height position (H2) of the upper end of the first layer (L1).

Description

Compressor and Refrigeration Device

[0001] It relates to a compressor and a refrigeration device.

[0002] Patent Document 1 (Japanese Patent Application Laid-Open No. 2024-13789) discloses a refrigeration device including a scroll compressor. In such a refrigeration device, for example, a hydrofluorocarbon (HFC) refrigerant is used. However, in recent years, the adoption of propane (R290) refrigerant has been progressing in response to the F-gas regulations by the European Union and for environmental protection.

[0003] The propane refrigerant has a larger amount of dissolution in the refrigeration oil compared to the HFC refrigerant. When using the propane refrigerant, the viscosity of the refrigeration oil is likely to decrease. Therefore, in a compressor using the propane refrigerant, a refrigeration oil in which the mixture with the refrigerant separates into two layers under predetermined conditions is used. In that case, the mixture in the layer with a higher refrigerant concentration may be supplied to the sliding part of the compressor, which may reduce the reliability of the compressor.

[0004] The compressor according to the first aspect includes a casing, a compression mechanism, a motor, and a housing. The casing stores refrigeration oil inside. The compression mechanism is housed inside the casing and compresses the refrigerant. The motor is housed inside the casing and drives the compression mechanism. The housing is housed inside the casing. The housing has a first space, a first oil supply passage, and a second oil supply passage. The first space is a supply source of the refrigeration oil supplied to the sliding part inside the casing. The first space is located below the sliding part. The first oil supply passage communicates with the sliding part. The second oil supply passage communicates with the first space through a first opening and also communicates with the first oil supply passage through a second opening. Inside the first space, the refrigeration oil mixed with the refrigerant separates into a first layer and a second layer above the first layer in a first state. The first height position of the upper end of the first opening is lower than the second height position of the upper end of the first layer.

[0005] The compressor according to the first aspect facilitates the supply of the mixture in the layer with a higher concentration of refrigeration oil to the sliding part inside the compressor when the mixture of the refrigeration oil and the refrigerant inside the compressor separates into two layers, thereby suppressing a decrease in the reliability of the compressor.

[0006] The compressor in the second view is the compressor in the first view, and the third height position of the upper end of the second opening is lower than the second height position.

[0007] The second aspect of the compressor is to facilitate the flow of a mixture with a higher concentration of refrigerant oil from the first opening to the second opening, thereby suppressing a decrease in the reliability of the compressor.

[0008] The compressor in the third viewpoint is the compressor in the second viewpoint, and the third height position is the same as the first height position.

[0009] The third-party compressor is designed to make it easier for the mixture with a higher refrigerant concentration to return to the first space even if it flows into the second oil supply passage, thereby suppressing a decrease in the reliability of the compressor.

[0010] The compressor in the fourth viewpoint is the compressor in the second viewpoint, and the third height position is lower than the first height position.

[0011] The fourth aspect of the compressor is designed to suppress a decrease in compressor reliability by making it easier for the mixture of layers with higher refrigerant concentrations to return to the first space even if it flows into the second oil supply passage.

[0012] The compressor of the fifth viewpoint is one of the compressors of the first to fourth viewpoints, wherein the cross-sectional area of ​​the first space at the first height position is smaller than the cross-sectional area of ​​the first space at the fourth height position at the upper end of the second layer.

[0013] The compressor in the fifth view has a first space having a shape that causes the upper surface height of the layer with a higher concentration of refrigerant oil to be higher. Therefore, the compressor in the fifth view facilitates the supply of the mixture of the layer with a higher concentration of refrigerant oil to the sliding parts, thereby suppressing a decrease in the reliability of the compressor.

[0014] The compressor in the sixth perspective is the compressor in the fifth perspective, wherein the first space has a range from the first height position to the fourth height position, and the cross-sectional area gradually decreases from the fourth height position toward the first height position.

[0015] The sixth aspect of the compressor facilitates the supply of a mixture with a higher concentration of refrigerant oil to the sliding parts, thereby suppressing a decrease in the reliability of the compressor.

[0016] The compressor of the seventh viewpoint is a compressor of the fifth or sixth viewpoint, wherein the first space has a cross-sectional area that decreases discontinuously from the fourth height position to the first height position in the range from the first height position to the fourth height position.

[0017] The seventh aspect of the compressor facilitates the supply of a mixture with a higher concentration of refrigerant oil to the sliding parts, thereby suppressing a decrease in the reliability of the compressor.

[0018] The compressor of the eighth viewpoint is one of the compressors of the first to seventh viewpoints, wherein the first space is a groove formed on the surface of the housing.

[0019] The compressor of the ninth aspect is one of the compressors of the first to eighth aspects, and the compression mechanism has a fixed scroll and a movable scroll. A motor rotates the movable scroll relative to the fixed scroll. The sliding part is the sliding surface between the fixed scroll and the movable scroll.

[0020] The compressor of the tenth perspective is one of the compressors of the first to ninth perspectives, wherein the concentration of the refrigerant oil in the first layer is greater than the concentration of the refrigerant oil in the second layer.

[0021] The compressor of the eleventh perspective is one of the compressors of the first to tenth perspectives, wherein the first state includes a state in which the motor has stopped driving and a predetermined time has elapsed.

[0022] The compressor of the twelfth perspective is one of the compressors of the first to eleventh perspectives, and the refrigerant is a natural refrigerant.

[0023] The compressor of the 13th aspect is the compressor of the 12th aspect, wherein the refrigerant is a single refrigerant consisting of hydrocarbons, or a mixed refrigerant containing hydrocarbons.

[0024] The compressor in the 14th perspective is the compressor in the 13th perspective, and the refrigerant is propane.

[0025] The compressor of the 15th aspect is one of the compressors of the 1st to 14th aspects, and the refrigerant oil is an incompatible oil that is incompatible with the refrigerant.

[0026] The compressor of the 16th aspect is the compressor of the 15th aspect, wherein the refrigeration oil contains any of polyalkylene glycol, polyvinyl ether, or polyol ester.

[0027] The compressor in the 17th aspect is the compressor in the 16th aspect, and the refrigerant oil is monoal type polyalkylene glycol.

[0028] The refrigeration system of the 18th aspect comprises one of the compressors of the first to 17th aspects.

[0029] This is a refrigerant circuit diagram of the refrigeration device 1 of the first embodiment. This is a longitudinal cross-sectional view of the scroll compressor 101 of the first embodiment. This is a bottom view of the fixed scroll 24 of the first embodiment. This is a top view of the movable scroll 26 of the first embodiment. This is a perspective view of the Oldham joint 39 of the first embodiment. This is a diagram illustrating the state of the mixture of propane and PAG oil. This is a longitudinal cross-sectional view of the vicinity of the second oil supply passage 23d of the first embodiment. This is an enlarged view of Figure 2. This is a longitudinal cross-sectional view of the vicinity of the second oil supply passage 23d of the second embodiment. This is a longitudinal cross-sectional view of the vicinity of the second oil supply passage 23d of modified example A. This is a longitudinal cross-sectional view of the vicinity of the second oil supply passage 23d of modified example B. This is a longitudinal cross-sectional view of the vicinity of the second oil supply passage 23d of modified example C. This is a longitudinal cross-sectional view of the vicinity of the second oil supply passage 23d of modified example D.

[0030] -First Embodiment- (1) As shown in the overall configuration diagram 1, the scroll compressor 101 is provided in the refrigeration system 1. The refrigeration system 1 is, for example, an air conditioning system. The refrigeration system 1 includes a refrigerant circuit 100 into which a refrigerant is filled. The refrigerant circuit 100 includes a scroll compressor 101, a radiator 2, a pressure reducing mechanism 3, and a heat absorber 4. The radiator 2 and the heat absorber 4 are heat exchangers. The pressure reducing mechanism 3 is, for example, an expansion valve. The refrigerant circuit 100 performs a vapor compression type refrigeration cycle.

[0031] As shown in Figure 2, the scroll compressor 101 comprises a casing 10, a compression mechanism 15, a housing 23, an Oldham coupling 39, a motor 16, a lower bearing 60, a crankshaft 17, an intake pipe 19, and a discharge pipe 20.

[0032] (1-1) Casing 10 The casing 10 has a cylindrical body casing portion 11, a bowl-shaped upper wall portion 12, and a bowl-shaped bottom wall portion 13. The upper wall portion 12 is airtightly welded to the upper end of the body casing portion 11. The bottom wall portion 13 is airtightly welded to the lower end of the body casing portion 11. The casing 10 is arranged such that the longitudinal direction of the body casing portion 11 is aligned with the vertical direction.

[0033] The casing 10 houses the compression mechanism 15, the housing 23, the Oldham joint 39, the motor 16, the lower bearing 60, and the crankshaft 17. The suction pipe 19 and the discharge pipe 20 are hermetically welded to the casing 10.

[0034] An oil reservoir 10a is formed at the bottom of the internal space of the casing 10, where refrigerant oil is stored. The refrigerant oil is a lubricant used to maintain good lubrication of the compression mechanism 15 and the crankshaft 17, etc., during the operation of the scroll compressor 101.

[0035] (1-2) Compression mechanism 15 The compression mechanism 15 draws in and compresses a low-temperature, low-pressure refrigerant gas and discharges a high-temperature, high-pressure refrigerant gas (hereinafter referred to as "compressed refrigerant"). The compression mechanism 15 has a fixed scroll 24 and a movable scroll 26. The fixed scroll 24 is fixed to the inner circumferential surface of the casing 10. The movable scroll 26 performs a rotational motion relative to the fixed scroll 24.

[0036] As shown in Figure 3, the fixed scroll 24 has a fixed end plate 24a, a fixed lap 24b, and an outer peripheral wall 24c. The fixed end plate 24a has a disc shape. The fixed lap 24b has a spiral shape when viewed along the vertical direction. The outer peripheral wall 24c has an annular shape when viewed along the vertical direction. The outer peripheral wall 24c is provided on the outer edge of the lower surface of the fixed end plate 24a. The fixed lap 24b is provided on the lower surface of the fixed end plate 24a, inside the outer peripheral wall 24c. When viewed along the vertical direction, the fixed lap 24b extends from the starting point of the winding located in the center of the fixed end plate 24a toward the ending point of the winding that connects to the outer peripheral wall 24c. Two fixed keyways 24g are formed on the lower surface of the outer peripheral wall 24c.

[0037] As shown in Figure 4, the movable scroll 26 has a movable end plate 26a and a movable wrap 26b. The movable end plate 26a has a disc shape. The movable wrap 26b is provided on the upper surface of the movable end plate 26a. When viewed along the vertical direction, the movable wrap 26b has a spiral shape. When viewed along the vertical direction, the movable wrap 26b extends from the starting point of the winding located in the center of the movable end plate 26a to the ending point located on the outside of the movable end plate 26a. As shown in Figure 2, an upper end bearing 26c is provided in the center of the lower surface 26g of the movable end plate 26a. The upper end bearing 26c has a cylindrical shape. Two movable keyways 26d are formed on the lower surface 26g of the movable end plate 26a.

[0038] The compression mechanism 15 forms a compression chamber 40. The compression chamber 40 is formed between the fixed scroll 24 and the movable scroll 26. The fixed scroll 24 and the movable scroll 26 are arranged so that the fixed-side wrap 24b and the movable-side wrap 26b interlock. The lower surface of the outer peripheral wall 24c of the fixed scroll 24 faces the movable scroll 26. The upper surface of the movable-side end plate 26a of the movable scroll 26 faces the fixed scroll 24. While the movable scroll 26 is rotating, the lower surface of the outer peripheral wall 24c slides against the upper surface of the movable-side end plate 26a.

[0039] A suction port 24d is formed in the fixed scroll 24. The suction port 24d opens near the end of the winding of the fixed-side wrap 24b. The downstream end of the suction pipe 19 is connected to the suction port 24d. The suction port 24d communicates with the compression chamber 40.

[0040] A cylindrical recess, or enlarged recess 42, is formed on the upper surface of the fixed end plate 24a of the fixed scroll 24. The enlarged recess 42 is covered by a cover member 44. A discharge hole 41 is formed on the bottom surface of the enlarged recess 42. The discharge hole 41 is located in the center of the fixed end plate 24a. The discharge hole 41 is a hole that penetrates the fixed end plate 24a vertically. The discharge hole 41 connects the compression chamber 40 and the enlarged recess 42.

[0041] On the fixed-side mirror plate 24a and the outer peripheral wall 24c, a first refrigerant flow path (not shown) is formed. The first refrigerant flow path communicates with the enlarged recess 42. The first refrigerant flow path communicates with a second refrigerant flow path (not shown) of the housing 23 on the lower surface of the outer peripheral wall 24c.

[0042] As shown in FIG. 3, a fixed-side oil groove 80 is formed in a first thrust surface 24e which is the lower surface of the outer peripheral wall 24c of the fixed scroll 24. The fixed-side oil groove 80 extends in the circumferential direction of the fixed scroll 24. The circumferential direction of the fixed scroll 24 is a direction substantially along the inner peripheral surface of the outer peripheral wall 24c. At least a part of the fixed-side oil groove 80 has an arc shape.

[0043] While the movable scroll 26 is turning, the first thrust surface 24e of the fixed scroll 24 slides on a second thrust surface 26e which is the upper surface of the movable-side mirror plate 26a of the movable scroll 26. The first thrust surface 24e and the second thrust surface 26e are sliding surfaces between the fixed scroll 24 and the movable scroll 26. The first thrust surface 24e and the second thrust surface 26e correspond to the sliding parts of the compression mechanism 15.

[0044] An oil passage 24f for supplying oil to the fixed-side oil groove 80 is formed in the fixed scroll 24. The oil passage 24f is formed inside the outer peripheral wall 24c. One end of the oil passage 24f opens inside the fixed-side oil groove 80 and communicates with the fixed-side oil groove 80. The other end of the oil passage 24f opens on the lower surface of the outer peripheral wall 24c and communicates with a first oil supply passage 23c described later.

[0045] A first communication passage 24h is formed in the outer peripheral wall 24c of the fixed scroll 24. The first communication passage 24h is a groove formed on the lower surface of the outer peripheral wall 24c. The inner end portion of the first communication passage 24h opens on the inner peripheral surface of the outer peripheral wall 24c and communicates with the compression chamber 40. The first communication passage 24h is provided at a position communicating with the compression chamber 40 in an intermediate pressure state. The pressure in the compression chamber 40 in the intermediate pressure state is higher than the pressure of the refrigerant before compression and lower than the pressure of the compressed refrigerant.

[0046] On the outer peripheral portion of the movable mirror plate 26a of the movable scroll 26, a second communication passage 26h is formed. The second communication passage 26h is a hole that vertically penetrates the movable mirror plate 26a. During the turning of the movable scroll 26, the upper end of the second communication passage 26h intermittently communicates with the first communication passage 24h. The lower end of the second communication passage 26h communicates with an intermediate pressure space 72 to be described later.

[0047] (1-3) Housing 23 The housing 23 is disposed below the compression mechanism 15 and above the motor 16. The outer peripheral surface of the housing 23 is hermetically joined to the inner peripheral surface of the body casing portion 11. The internal space of the casing 10 is partitioned into a high-pressure space 71, an intermediate pressure space 72, and an upper space 73. The high-pressure space 71 is a space below the housing 23. The high-pressure space 71 is a space into which compressed refrigerant is discharged from the compression mechanism 15. The intermediate pressure space 72 is a space above the housing 23 and is a space surrounded by the housing 23, the fixed scroll 24, and the movable scroll 26. The upper space 73 is a space above the housing 23 and above the fixed scroll 24.

[0048] The intermediate pressure space 72 communicates with the compression chamber 40 in an intermediate pressure state via the first communication passage 24h and the second communication passage 26h. Therefore, the pressure in the intermediate pressure space 72 is lower than the pressure in the high-pressure space 71. Due to the pressures of the refrigerant in the high-pressure space 71 and the intermediate pressure space 72, the movable scroll 26 during turning is pressed against the fixed scroll 24.

[0049] The housing 23 mounts the fixed scroll 24 and sandwiches the movable scroll 26 together with the fixed scroll 24. On the outer peripheral portion of the housing 23, a second refrigerant flow path is formed. The second refrigerant flow path is a hole that vertically penetrates the outer peripheral portion of the housing 23. The second refrigerant flow path communicates with the first refrigerant flow path of the fixed scroll 24 on the upper surface of the housing 23. The second refrigerant flow path communicates with the high-pressure space 71 on the lower surface of the housing 23. Therefore, the compression chamber 40 of the compression mechanism 15 communicates with the high-pressure space 71 via the discharge hole 41, the enlarged recess 42, the first refrigerant flow path of the fixed scroll 24, and the second refrigerant flow path of the housing 23.

[0050] A recess called the crank chamber 23a is formed on the upper surface of the housing 23. A housing through hole 31 is formed in the housing 23. The housing through hole 31 is a hole that penetrates the housing 23 vertically from the center of the bottom surface of the crank chamber 23a to the center of the lower surface of the housing 23. Hereinafter, a part of the housing 23, and the part surrounding the housing through hole 31, will be referred to as the upper bearing 32. An annular groove 23g is formed on the outer circumference of the bottom surface of the crank chamber 23a. The annular groove 23g is a space that serves as a supply source for refrigerant oil supplied to the first thrust surface 24e and the second thrust surface 26e, which are sliding parts of the compression mechanism 15. The annular groove 23g is located below the sliding parts of the compression mechanism 15.

[0051] In this embodiment, the inner circumferential surface of the annular groove 23g is aligned vertically from the upper end of the annular groove 23g to the vicinity of the lower end of the annular groove 23g. In other words, the cross-sectional area of ​​the annular groove 23g is constant from the upper end of the annular groove 23g to the vicinity of the lower end of the annular groove 23g. The cross-sectional area of ​​the annular groove 23g is the area of ​​the annular groove 23g when cut along a plane perpendicular to the vertical direction.

[0052] The housing 23 has an oil discharge passage 23b that connects the crank chamber 23a and the high-pressure space 71. In the crank chamber 23a, the opening of the oil discharge passage 23b is formed near the bottom surface of the crank chamber 23a.

[0053] A first oil supply passage 23c and a second oil supply passage 23d are formed inside the housing 23. The first oil supply passage 23c and the second oil supply passage 23d are passages for supplying refrigerant oil stored in the annular groove 23g to the sliding parts of the compression mechanism 15. The first oil supply passage 23c extends in a substantially vertical direction. The upper end of the first oil supply passage 23c opens to the outer circumference of the upper surface of the housing 23. The upper end of the first oil supply passage 23c communicates with the oil passage 24f of the fixed scroll 24. One end of the second oil supply passage 23d communicates with the annular groove 23g. The other end of the second oil supply passage 23d communicates with the first oil supply passage 23c. A throttling mechanism (not shown) for reducing the pressure of the refrigerant oil flowing through the first oil supply passage 23c is arranged inside the first oil supply passage 23c.

[0054] (1-4) Oldham joint 39 The Oldham joint 39 is a component for suppressing the rotation of the revolving movable scroll 26. The Oldham joint 39 is positioned between the movable scroll 26 and the housing 23 in the intermediate pressure space 72.

[0055] As shown in Figure 5, the Oldham joint 39 has an annular body portion 39a, a pair of first key portions 39b, and a pair of second key portions 39c. The first key portions 39b and the second key portions 39c are portions that protrude from the upper surface of the annular body portion 39a. The first key portions 39b are located inside the fixed-side key groove 24g of the fixed scroll 24. The second key portions 39c are located inside the movable-side key groove 26d of the movable scroll 26. While the movable scroll 26 is orbiting, the first key portions 39b reciprocate within the fixed-side key groove 24g along the longitudinal direction of the fixed-side key groove 24g. While the movable scroll 26 is orbiting, the second key portions 39c reciprocate within the movable-side key groove 26d along the longitudinal direction of the movable-side key groove 26d. This suppresses the rotation of the orbiting movable scroll 26.

[0056] (1-5) Motor 16 The motor 16 is located below the housing 23. The motor 16 has a stator 51 and a rotor 52. The motor 16 drives the compression mechanism 15.

[0057] The stator 51 comprises a stator core 51a and a plurality of coils 51b. The stator core 51a is a cylindrical member fixed to the inner circumferential surface of the casing 10. The stator core 51a has a plurality of teeth (not shown). The coils 51b are formed by winding wire around the teeth.

[0058] Multiple core cuts are formed on the outer circumferential surface of the stator core 51a. The core cuts are grooves formed vertically from the upper end surface to the lower end surface of the stator core 51a.

[0059] The rotor 52 is a cylindrical member positioned inside the stator core 51a. An air gap is formed between the inner circumferential surface of the stator core 51a and the outer circumferential surface of the rotor 52. The rotor 52 is connected to the crankshaft 17. The rotor 52 is connected to the compression mechanism 15 via the crankshaft 17. The rotor 52 rotates the crankshaft 17 around the rotation axis 16a. The rotation axis 16a passes through the central axis of the rotor 52.

[0060] The motor 16 functions as a power source for compressing the gaseous refrigerant in the compression chamber 40 by rotating the movable scroll 26 via the rotation of the crankshaft 17.

[0061] (1-6) Lower bearing 60 The lower bearing 60 is located below the motor 16. The outer circumferential surface of the lower bearing 60 is joined to the inner circumferential surface of the casing 10. The lower bearing 60 rotatably supports the crankshaft 17.

[0062] (1-7) Crankshaft 17 The crankshaft 17 is positioned so that its axial direction is aligned with the vertical. The axis of the upper end of the crankshaft 17 is eccentric with respect to the axis of the portion excluding the upper end. The crankshaft 17 has a balance weight 18. The balance weight 18 is fixed in close contact with the crankshaft 17 at a height below the housing 23 and above the motor 16.

[0063] The crankshaft 17 is connected to the rotor 52 by passing vertically through the rotor 52's center of rotation. The upper end of the crankshaft 17 is fitted into the upper end bearing 26c of the movable scroll 26. This connects the crankshaft 17 to the movable scroll 26, and the rotation of the crankshaft 17 is transmitted to the movable scroll 26. The crankshaft 17 is rotatably supported by the upper bearing 32 and the lower bearing 60.

[0064] A main oil supply passage 61 is formed inside the crankshaft 17. The main oil supply passage 61 extends along the axial direction (vertical direction) of the crankshaft 17. The upper end of the main oil supply passage 61 communicates with the oil chamber 83, which is the space between the upper end surface of the crankshaft 17 and the lower surface 26g of the movable end plate 26a. The lower end of the main oil supply passage 61 communicates with the oil reservoir 10a.

[0065] The crankshaft 17 has a first auxiliary oil supply passage 61a, a second auxiliary oil supply passage 61b, and a third auxiliary oil supply passage 61c that branch off from the main oil supply passage 61. The first auxiliary oil supply passage 61a, the second auxiliary oil supply passage 61b, and the third auxiliary oil supply passage 61c extend horizontally. The first auxiliary oil supply passage 61a opens into the sliding portion between the crankshaft 17 and the upper end bearing 26c of the movable scroll 26. The second auxiliary oil supply passage 61b opens into the sliding portion between the crankshaft 17 and the upper bearing 32 of the housing 23. The third auxiliary oil supply passage 61c opens into the sliding portion between the crankshaft 17 and the lower bearing 60.

[0066] (1-8) Intake pipe 19 The intake pipe 19 is a pipe for introducing refrigerant from the refrigerant circuit to the compression mechanism 15 from outside the casing 10. The intake pipe 19 penetrates the upper wall portion 12 of the casing 10. Inside the casing 10, the end of the intake pipe 19 is fitted into the intake port 24d of the fixed scroll 24.

[0067] (1-9) Discharge pipe 20 The discharge pipe 20 is a pipe for discharging compressed refrigerant from the high-pressure space 71 to the outside of the casing 10. The discharge pipe 20 penetrates the body casing portion 11 of the casing 10. Inside the casing 10, the end of the discharge pipe 20 is located in the high-pressure space 71 above the motor 16 and below the housing 23.

[0068] (2) When the operating motor 16 of the scroll compressor 101 is driven, the crankshaft 17 connected to the rotor 52 of the motor 16 rotates. The rotational motion of the crankshaft 17 causes the movable scroll 26 to pivot around the axis of rotation 16a of the crankshaft 17. As a result, the movable scroll 26 pivots relative to the fixed scroll 24. During the pivoting of the movable scroll 26, its rotation is suppressed by the Oldham coupling 39.

[0069] (2-1) Refrigerant Flow The scroll compressor 101 compresses the low-pressure refrigerant flowing through the refrigerant circuit 100 and discharges compressed refrigerant. The refrigerant before compression passes through the suction pipe 19 and suction port 24d and is supplied to the compression chamber 40 of the compression mechanism 15. Due to the rotational movement of the movable scroll 26, the volume of the compression chamber 40 to which the refrigerant before compression is supplied decreases. As a result, the refrigerant is compressed in the compression chamber 40 and becomes compressed refrigerant. During the process of compressing the refrigerant, the compression chamber 40 becomes a compression chamber 40 in an intermediate pressure state.

[0070] The compressed refrigerant is discharged from the compression chamber 40 through the discharge hole 41 into the enlarged recess 42. The compressed refrigerant then passes through the first refrigerant flow path of the fixed scroll 24 and the second refrigerant flow path of the housing 23 and is supplied to the high-pressure space 71. The compressed refrigerant supplied to the high-pressure space 71 passes through the discharge pipe 20 and is discharged to the refrigerant circuit 100 outside the scroll compressor 101.

[0071] (2-2) Flow of refrigerant oil When compressed refrigerant is supplied to the high-pressure space 71, the pressure in the high-pressure space 71 increases. As a result, the refrigerant oil stored in the oil reservoir 10a of the high-pressure space 71 rises up the main oil supply passage 61 due to the pressure difference between the high-pressure space 71 and the oil chamber 83. The refrigerant oil rising up the main oil supply passage 61 is supplied to the first sliding part between the crankshaft 17 and the lower bearing 60, the second sliding part between the crankshaft 17 and the upper bearing 32, and the third sliding part between the crankshaft 17 and the upper end bearing 26c, respectively. The refrigerant oil that lubricates the first sliding part flows into the high-pressure space 71. The refrigerant oil that lubricates the second sliding part flows into the high-pressure space 71 and the crank chamber 23a. The refrigerant oil that lubricates the third sliding part flows into the crank chamber 23a.

[0072] The refrigerant oil that flows into the high-pressure space 71 from the first and second sliding parts returns to the oil reservoir 10a. A portion of the refrigerant oil that flows into the crank chamber 23a from the second and third sliding parts passes through the oil discharge passage 23b and flows into the high-pressure space 71 and returns to the oil reservoir 10a. Most of the refrigerant oil that flows into the crank chamber 23a passes through the annular groove 23g, the second oil supply passage 23d, the first oil supply passage 23c, and the oil passage 24f and is supplied to the fixed-side oil groove 80. The refrigerant oil supplied to the fixed-side oil groove 80 flows into the compression chamber 40 while sealing the first thrust surface 24e. The refrigerant oil that flows into the compression chamber 40 is mixed with the compressed refrigerant in the form of tiny oil droplets and flows into the high-pressure space 71 together with the compressed refrigerant and returns to the oil reservoir 10a.

[0073] (3) Detailed Configuration The refrigerant oil used in the compressor of a refrigeration system is classified into miscible oil and miscible oil. Miscible oil is refrigerant oil that is incompatible with the refrigerant. Miscible oil is refrigerant oil that has lower solubility with the refrigerant compared to miscible oil. When miscible oil is used, refrigerant oil in which the refrigerant is uniformly dissolved is stored inside the compressor. When miscible oil is used, depending on conditions such as temperature, refrigerant oil in a two-layer separation state may be stored inside the compressor. A two-layer separation state is a state in which, when the refrigerant and refrigerant oil are mixed, the refrigerant and refrigerant oil do not dissolve and separate into two layers. In a two-layer separation state, refrigerant oil is separated into a layer with high refrigerant solubility and a layer with low refrigerant solubility. The refrigerant oil in the layer with high refrigerant solubility has a higher refrigerant content and therefore a lower density compared to the refrigerant oil in the layer with low refrigerant solubility. Therefore, in a two-layer separated refrigerant oil, the layer with higher refrigerant solubility forms above the layer with lower refrigerant solubility.

[0074] In this embodiment, the refrigerant used in the scroll compressor 101 is propane (R290). The refrigerant is not limited to propane, as long as it is a single refrigerant consisting of hydrocarbons or a mixed refrigerant containing hydrocarbons. Hydrocarbons are selected from the group consisting of, for example, propane, butane, and isobutane. The refrigerant may also be a natural refrigerant other than hydrocarbons. Natural refrigerants include, for example, at least one of carbon dioxide, ammonia, and water.

[0075] In this embodiment, the refrigeration oil used in the scroll compressor 101 is a monool-type polyalkylene glycol, which is an incompatible oil. A monool-type polyalkylene glycol is a polyalkylene glycol having one hydroxyl group at one end. The refrigeration oil is not limited to monool-type polyalkylene glycol, as long as it is an incompatible oil containing any of polyalkylene glycol, polyvinyl ether, or polyol ester. Hereinafter, the monool-type polyalkylene glycol used as the refrigeration oil in the scroll compressor 101 will be referred to as "PAG oil".

[0076] A mixture of PAG oil and propane will separate into two layers when the wt% content of PAG oil in the mixture and the temperature of the mixture meet predetermined conditions. In Figure 6, the mixture in the "dissolved region" is in a miscible state where propane is uniformly dissolved in the PAG oil, while the mixture in the "separated region" is in a two-layer separated state. As shown in Figure 7, the two-layer separated mixture is separated into two layers: a first layer L1 and a second layer L2. The second layer L2 is located above the first layer L1. 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 wt% content of PAG oil in the mixture. Specifically, the concentration of PAG oil is the value obtained by dividing the mass of PAG oil contained in the mixture 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.

[0077] In this embodiment, the annular groove 23g is a space in which a mixture of PAG oil and propane is stored. As shown in Figure 7, the mixture in the annular groove 23g separates into a two-layer separation state, into a first layer L1 and a second layer L2, under predetermined conditions.

[0078] As shown in Figure 7, the second refueling passage 23d communicates with the annular groove 23g via the first opening 23e. The second refueling passage 23d communicates with the first refueling passage 23c via the second opening 23f. The first opening 23e is formed on the side surface of the annular groove 23g.

[0079] The scroll compressor 101 has a configuration in which the first height position H1 at the upper end of the first opening 23e is lower than the second height position H2 at the upper end of the first layer L1. The first height position H1 and the second height position H2 are height positions relative to the reference height position H0 of the lower end 23h1 of the annular groove 23g. The second height position H2 is between the height position of the lower end 23h1 of the annular groove 23g and the height position of the upper end 23h2 of the annular groove 23g. The height position of the upper end of the second layer L2 corresponds to the height position of the upper end 23h2 of the annular groove 23g. Since the first height position H1 is lower than the second height position H2, the first opening 23e is immersed in the mixture of the first layer L1.

[0080] In this embodiment, the scroll compressor 101 further has a configuration in which the third height position H3 at the upper end of the second opening 23f is higher than the first height position H1, due to constraints on the cross-sectional shape of the housing 23 near the second oil supply passage 23d. The third height position H3 is a height position relative to the reference height position H0. The second oil supply passage 23d is inclined vertically upward from the first opening 23e toward the second opening 23f. Also, as shown in Figure 7, the scroll compressor 101 has a configuration in which the third height position H3 is higher than the second height position H2.

[0081] (4) Features The scroll compressor 101 uses propane as a refrigerant and PAG oil as refrigeration oil. Inside the casing 10, the mixture of propane and PAG oil is in a two-layer separation state in the first state. The first state includes a stopped state in which a predetermined time has elapsed since the motor 16 stopped running. In the stopped state, if the ambient temperature is low, the mixture stored inside the casing 10 may be in a two-layer separation state in the "separation region" shown in Figure 6.

[0082] The mixture stored in the annular groove 23g flows from the first opening 23e into the second oil supply passage 23d, passes through the first oil supply passage 23c and the oil passage 24f, and is supplied to the fixed-side oil groove 80. When the mixture stored in the annular groove 23g is in a two-layer separation state, it separates into a first layer L1 and a second layer L2. The mixture of the second layer L2 has a lower viscosity than the mixture of the first layer L1 because it has a higher refrigerant content. Therefore, when the mixture of the second layer L2 flows into the second oil supply passage 23d and is supplied to the fixed-side oil groove 80, problems such as seizure and abnormal wear of the sliding parts of the compression mechanism 15 may occur, potentially reducing the reliability of the scroll compressor 101.

[0083] In the scroll compressor 101, the first opening 23e is formed such that the first height position H1 is lower than the second height position H2. Therefore, during operation of the scroll compressor 101, the first opening 23e is always immersed in the mixture of the first layer L1, so that the mixture of the second layer L2 does not flow from the first opening 23e into the second oil supply passage 23d and is supplied to the fixed-side oil groove 80. In other words, during operation of the scroll compressor 101, in the annular groove 23g, the mixture of the first layer L1 flows from the first opening 23e into the second oil supply passage 23d and is supplied to the fixed-side oil groove 80. The mixture of the first layer L1 has a higher viscosity than the mixture of the second layer L2 because it contains a larger amount of refrigerant oil. Therefore, by setting the first opening 23e at an appropriate height position, the scroll compressor 101 can suppress the decrease in reliability caused by the mixture of the second layer L2 flowing into the second oil supply passage 23d.

[0084] Furthermore, the solubility of polyalkylene glycol in propane can be controlled by adjusting the end groups. The monool-type polyalkylene glycol used in the scroll compressor 101 of this embodiment has a higher viscosity index compared to polyalkylene glycols without hydroxyl groups at both ends, polyol esters, polyvinyl ethers, and mineral oil. Viscosity index is the degree of viscosity change with temperature. When propane dissolves in the refrigeration oil, the viscosity of the refrigeration oil decreases, which may cause problems such as seizure and abnormal wear of the sliding parts of the compression mechanism 15. To suppress the occurrence of these problems, it is preferable to use refrigeration oil with a high viscosity index. Therefore, by using monool-type polyalkylene glycol in the scroll compressor 101, a decrease in reliability can be suppressed.

[0085] -Second Embodiment- (1) Configuration The scroll compressor 101 of the second embodiment has the same basic configuration and operation as the scroll compressor 101 of the first embodiment. The differences from the first embodiment will be explained below.

[0086] In this embodiment, the cross-sectional area of ​​the annular groove 23g is not constant from the upper end 23h2 of the annular groove 23g to the vicinity of the lower end 23h1 of the annular groove 23g. Specifically, the cross-sectional area of ​​the annular groove 23g at the first height position H1 is smaller than the cross-sectional area of ​​the annular groove 23g at the fourth height position H4 at the upper end of the second layer L2. The fourth height position H4 is a height position relative to the reference height position H0. The fourth height position H4 corresponds to the height position of the upper end 23h2 of the annular groove 23g and the height position of the bottom surface of the crank chamber 23a. Preferably, the cross-sectional area of ​​the annular groove 23g at the first height position H1 is 90% or less of the cross-sectional area of ​​the annular groove 23g at the fourth height position H4.

[0087] In this embodiment, as shown in Figure 8, the cross-sectional area of ​​the annular groove 23g gradually decreases from the fourth height position H4 towards the first height position H1 within the range from the first height position H1 to the fourth height position H4. Specifically, the annular groove 23g has an inclined surface 23g1, which is an inner circumferential surface that is inclined with respect to the vertical from the upper end 23h2 of the annular groove 23g to the vicinity of the lower end 23h1 of the annular groove 23g. The inclined surface 23g1 is formed such that the cross-sectional area of ​​the annular groove 23g gradually decreases from the upper end 23h2 of the annular groove 23g to the vicinity of the lower end 23h1 of the annular groove 23g.

[0088] The annular groove 23g may have a plurality of inclined surfaces 23g1.

[0089] (2) Features The annular groove 23g of this embodiment has an inclined surface 23g1, so that the cross-sectional area of ​​the annular groove 23g gradually decreases from the upper end 23h2 of the annular groove 23g to the vicinity of the lower end 23h1 of the annular groove 23g. Therefore, the annular groove 23g of this embodiment has a shape in which the second height position H2 is higher compared to the annular groove 23g of the first embodiment.

[0090] In the scroll compressor 101, the first opening 23e is formed such that the first height position H1 is lower than the second height position H2. Therefore, during operation of the scroll compressor 101, the mixture of the first layer L1 flows from the first opening 23e into the second oil supply passage 23d in the annular groove 23g and is supplied to the fixed-side oil groove 80. Accordingly, the scroll compressor 101 can suppress the decrease in reliability caused by the mixture of the second layer L2 flowing into the second oil supply passage 23d by providing an inclined surface 23g1 in the annular groove 23g to raise the second height position H2.

[0091] - Modification - (1) Modification A As shown in Figure 7, the scroll compressor 101 of the first embodiment has a configuration in which the third height position H3 is higher than the second height position H2. Alternatively, as shown in Figure 9, the scroll compressor 101 may have a configuration in which the third height position H3 is lower than the second height position H2.

[0092] In this modified example, the second opening 23f is formed such that the third height position H3 is lower than the second height position H2. As a result, the height difference between the first opening 23e and the second opening 23f is suppressed, making it easier for the mixture of the first layer L1 to flow through the second oil supply passage 23d from the first opening 23e towards the second opening 23f. Consequently, the mixture of the first layer L1 is more easily supplied from the annular groove 23g to the fixed-side oil groove 80, thereby suppressing a decrease in the reliability of the scroll compressor 101.

[0093] In this modified example, similar to the first embodiment, the scroll compressor 101 has a configuration in which the third height position H3 is higher than the first height position H1.

[0094] This modified example can be applied to the scroll compressor 101 of the second embodiment.

[0095] (2) Modification B As shown in Figure 7, the scroll compressor 101 of the first embodiment has a configuration in which the third height position H3 is higher than the first height position H1. Alternatively, as shown in Figure 10, the scroll compressor 101 may have the same configuration in which the third height position H3 is the same as the first height position H1.

[0096] In this modified example, the first opening 23e and the second opening 23f are formed such that the third height position H3 does not become higher than the first height position H1. Therefore, even if the mixture of the second layer L2 flows into the second oil supply passage 23d, the mixture of the second layer L2 is more likely to return from the second oil supply passage 23d to the annular groove 23g. Consequently, the mixture of the second layer L2 is less likely to be supplied from the annular groove 23g to the fixed-side oil groove 80, thus suppressing a decrease in the reliability of the scroll compressor 101.

[0097] This modified example can be applied to the scroll compressor 101 of the second embodiment.

[0098] (3) Modification C As shown in Figure 7, the scroll compressor 101 of the first embodiment has a configuration in which the third height position H3 is higher than the first height position H1. Alternatively, as shown in Figure 11, the scroll compressor 101 may have a configuration in which the third height position H3 is lower than the first height position H1.

[0099] In this modified example, the first opening 23e and the second opening 23f are formed such that the third height position H3 is lower than the first height position H1. Therefore, even if the mixture of the second layer L2 flows into the second oil supply passage 23d, the mixture of the second layer L2 is more likely to return from the second oil supply passage 23d to the annular groove 23g. Consequently, the mixture of the second layer L2 is less likely to be supplied from the annular groove 23g to the fixed-side oil groove 80, thus suppressing a decrease in the reliability of the scroll compressor 101.

[0100] This modified example can be applied to the scroll compressor 101 of the second embodiment.

[0101] (4) Modification D In this modification, similar to the second embodiment, the cross-sectional area of ​​the annular groove 23g at the first height position H1 is smaller than the cross-sectional area of ​​the annular groove 23g at the fourth height position H4 at the upper end of the second layer L2. Preferably, the cross-sectional area of ​​the annular groove 23g at the first height position H1 is 90% or less of the cross-sectional area of ​​the annular groove 23g at the fourth height position H4.

[0102] In this modified example, as shown in Figure 12, the cross-sectional area of ​​the annular groove 23g becomes discontinuously smaller from the fourth height position H4 toward the first height position H1 within the range from the first height position H1 to the fourth height position H4. Specifically, the annular groove 23g has a stepped surface 23g2 perpendicular to the vertical direction between the upper end 23h2 and the lower end 23h1 of the annular groove 23g. The cross-sectional area of ​​the annular groove 23g above the stepped surface 23g2 is constant. The cross-sectional area of ​​the annular groove 23g below the stepped surface 23g2 is constant. Therefore, the cross-sectional area of ​​the annular groove 23g decreases at the height of the stepped surface 23g2 toward the first height position H1 from the fourth height position H4. It is preferable that the height of the stepped surface 23g2 is below the second height position H2.

[0103] The annular groove 23g may have multiple stepped surfaces 23g2. The annular groove 23g may have both an inclined surface 23g1 and stepped surfaces 23g2.

[0104] In this embodiment, the annular groove 23g has a stepped surface 23g2, which causes the cross-sectional area of ​​the annular groove 23g to decrease discontinuously from the upper end 23h2 of the annular groove 23g to the vicinity of the lower end 23h1 of the annular groove 23g. Therefore, the annular groove 23g in this embodiment has a shape that results in a higher second height position H2 compared to the annular groove 23g of the first embodiment. Accordingly, the scroll compressor 101 can suppress a decrease in reliability caused by the mixture of the second layer L2 flowing into the second oil supply passage 23d by providing a stepped surface 23g2 in the annular groove 23g and raising the second height position H2.

[0105] This modified version can be applied to the scroll compressor 101 of modified versions A to C.

[0106] While embodiments of this disclosure have been described above, it should be understood that various modifications to the form and details are possible without departing from the spirit and scope of this disclosure as described in the claims.

[0107] 1: Refrigeration device 10: Casing 15: Compression mechanism 16: Motor 23: Housing 23c: First oil supply passage 23d: Second oil supply passage 23e: First opening 23f: Second opening 23g: Annular groove (first space) 24: Fixed scroll 24e: First thrust surface (sliding part) 26: Movable scroll 26e: Second thrust surface (sliding part) 101: Scroll compressor (compressor) H1: First height position H2: Second height position H3: Third height position H4: Fourth height position L1: First layer L2: Second layer

[0108] Japanese Patent Publication No. 2024-13789

Claims

1. The refrigerant comprises: a casing (10) in which refrigerant oil is stored; a compression mechanism (15) housed within the casing for compressing the refrigerant; a motor (16) housed within the casing for driving the compression mechanism; and a housing (23) housed within the casing, wherein the housing has: a first space (23g) located below the sliding parts, which is a source of the refrigerant oil supplied to the sliding parts (24e, 26e) within the casing; a first oil supply passage (23c) communicating with the sliding parts; and a second oil supply passage (23d) communicating with the first space via a first opening (23e) and with the first oil supply passage via a second opening (23f). Within the first space, the refrigerant oil mixed with the refrigerant separates in a first state into a first layer (L1) and a second layer (L2) above the first layer, and the first height position (H1) of the upper end of the first opening is lower than the second height position (H2) of the upper end of the first layer, in the compressor (101).

2. The compressor according to claim 1, wherein the third height position (H3) of the upper end of the second opening is lower than the second height position.

3. The compressor according to claim 2, wherein the third height position is the same as the first height position.

4. The compressor according to claim 2, wherein the third height position is lower than the first height position.

5. The compressor according to any one of claims 1 to 4, wherein the cross-sectional area of ​​the first space at the first height position is smaller than the cross-sectional area of ​​the first space at the fourth height position (H4) of the upper end of the second layer.

6. The compressor according to claim 5, wherein the first space has a cross-sectional area that gradually decreases from the fourth height position toward the first height position in the range from the first height position toward the fourth height position.

7. The compressor according to claim 5 or 6, wherein the first space has a cross-sectional area that decreases discontinuously from the fourth height position toward the first height position in the range from the first height position toward the fourth height position.

8. The compressor according to any one of claims 1 to 7, wherein the first space is a groove formed on the surface of the housing.

9. The compressor according to any one of claims 1 to 8, wherein the compression mechanism comprises a fixed scroll (24) and a movable scroll (26), the motor rotates the movable scroll relative to the fixed scroll, and the sliding portion is the sliding surface between the fixed scroll and the movable scroll.

10. The compressor according to any one of claims 1 to 9, wherein the concentration of the refrigerant oil in the first layer is greater than the concentration of the refrigerant oil in the second layer.

11. The compressor according to any one of claims 1 to 10, wherein the first state includes a state in which the motor has stopped driving and a predetermined time has elapsed.

12. The compressor according to any one of claims 1 to 11, wherein the refrigerant is a natural refrigerant.

13. The compressor according to claim 12, wherein the refrigerant is a single refrigerant consisting of hydrocarbons, or a mixed refrigerant containing hydrocarbons.

14. The compressor according to claim 13, wherein the refrigerant is propane.

15. The compressor according to any one of claims 1 to 14, wherein the refrigeration oil is an incompatible oil that is incompatible with the refrigerant.

16. The compressor according to claim 15, wherein the refrigeration oil comprises any one of polyalkylene glycol, polyvinyl ether, or polyol ester.

17. The compressor according to claim 16, wherein the refrigeration oil is a monoal type polyalkylene glycol.

18. A refrigeration apparatus (1) comprising a compressor according to any one of claims 1 to 17.

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