Scroll compressor and refrigeration cycle device
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Filing Date
- 2026-03-25
- Publication Date
- 2026-06-29
Abstract
Description
Scroll compressor and refrigeration cycle device
[0001] The present disclosure relates to a scroll compressor that compresses a refrigerant and a refrigeration cycle device.
[0002] In recent years, efforts to realize a carbon-free society have been accelerating worldwide, and refrigerant regulations have been accelerating in the air conditioning and refrigeration field. This has led to a demand for the development of air conditioners and compressors for use with low-density refrigerants. One method for dealing with low-density refrigerants is to increase the stroke volume of the compressor. In this case, the fixed scroll and the orbiting scroll must be enlarged. Therefore, it has been proposed to increase the diameter of the main shell so that the larger fixed scroll and the orbiting scroll can be accommodated inside.
[0003] Another method for increasing the size of the fixed scroll and the orbiting scroll is disclosed in Patent Document 1, which discloses a scroll compressor having a frame-outer-wall-less structure. In Patent Document 1, the main frame and the fixed scroll are connected by a rod-shaped connecting member, and the fixed scroll is fixed to the shell by shrink fitting, thereby increasing the stroke volume without increasing the diameter of the main shell.
[0004] International Publication No. 2019 / 207759
[0005] However, increasing the diameter of the shell requires that components other than the fixed scroll and the orbiting scroll fixed to the shell, such as the stator or subframe, be enlarged. This increases costs. Furthermore, when a frame-outer-wall-less structure is adopted, as in the scroll compressor disclosed in Patent Document 1, the frame outer wall must be eliminated and the fixed scroll must be fixed to the shell by shrink fitting. This requires high assembly precision and makes assembly difficult. Furthermore, there is also a demand for improved compression efficiency.
[0006] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a scroll compressor and a refrigeration cycle device that can increase the stroke volume at low cost, can be easily assembled, and improves compression efficiency.
[0007] A scroll compressor according to the present disclosure comprises a shell forming an outer casing, an electric motor provided inside the shell, a rotating shaft attached to the electric motor and transmitting the rotational force of the electric motor, a compression mechanism that rotates in conjunction with the rotation of the rotating shaft to compress a refrigerant, and an intake pipe connected to a side of the shell and through which a refrigerant is drawn, the shell having a small diameter portion facing at least a part of the outer periphery of the electric motor, a large diameter portion facing the outer periphery of the compression mechanism and having a diameter larger than that of the small diameter portion, and a boundary portion located at the boundary between the small diameter portion and the large diameter portion, and the thickness of the shell satisfies the relationship: thickness of the small diameter portion > thickness of the large diameter portion.
[0008] The present disclosure provides an increased stroke volume that is cost-effective, easy to assemble, and provides improved compression efficiency.
[0009] 1 is a circuit diagram showing a refrigeration cycle device according to embodiment 1. FIG. 2 is a cross-sectional view showing a compressor according to embodiment 1. FIG. 3 is a top cross-sectional view showing a stator according to embodiment 1. FIG. 4 is a diagram showing a coil end according to embodiment 1. FIG. 5 is a top cross-sectional view showing a shell according to embodiment 1. FIG. 6 is a side cross-sectional view showing a shell according to embodiment 1. FIG. 7 is a cross-sectional view showing a compressor according to embodiment 2. FIG. 8 is a side cross-sectional view showing a shell according to embodiment 2.
[0010] Hereinafter, embodiments of a compressor 100 and a refrigeration cycle apparatus 110 according to the present disclosure will be described with reference to the drawings. Note that the present disclosure is not limited to the embodiments described below. Furthermore, in the following drawings, including FIG. 1, the dimensional relationships between components may differ from the actual relationships. Furthermore, in the following description, terms indicating directions are used as appropriate to facilitate understanding of the present disclosure, but these terms are used for the purpose of explaining the present disclosure and do not limit the present disclosure. Examples of terms indicating directions include "up," "down," "right," "left," "front," and "rear."
[0011] Embodiment 1. Fig. 1 is a circuit diagram showing a refrigeration cycle apparatus 110 according to embodiment 1. The refrigeration cycle apparatus 110 is, for example, an air conditioning apparatus that adjusts the air in a space to be air-conditioned, and as shown in Fig. 1, includes an outdoor unit 121 and an indoor unit 122. The outdoor unit 121 includes, for example, a compressor 100, a flow path switching device 112, an outdoor heat exchanger 113, an outdoor blower 114, and an expansion section 115. The indoor unit 122 includes, for example, an indoor heat exchanger 116 and an indoor blower 117.
[0012] The compressor 100, the flow switching device 112, the outdoor heat exchanger 113, the expansion section 115, and the indoor heat exchanger 116 are connected by refrigerant piping 124 to form a refrigerant circuit 123. The compressor 100 draws in low-temperature, low-pressure refrigerant, compresses it, and discharges it into high-temperature, high-pressure refrigerant. The compressor 100 is, for example, a capacity-controllable inverter compressor. The flow switching device 112 switches the refrigerant flow direction in the refrigerant circuit 123 and is, for example, a four-way valve. The outdoor heat exchanger 113 exchanges heat between, for example, outdoor air and the refrigerant. The outdoor heat exchanger 113 functions as a condenser during cooling operation and as an evaporator during heating operation. The expansion section 115 is a pressure-reducing valve or expansion valve that reduces the pressure of the refrigerant and expands it. The expansion section 115 is, for example, an electronic expansion valve whose opening is adjustable.
[0013] The indoor heat exchanger 116 exchanges heat between, for example, indoor air and a refrigerant. The indoor heat exchanger 116 acts as an evaporator during cooling operation and as a condenser during heating operation. The indoor blower 117 is a device that sends indoor air to the indoor heat exchanger 116.
[0014] (Operation Modes, Cooling Operation) Next, the operation modes of the refrigeration cycle apparatus 110 will be described. First, the cooling operation will be described. In the cooling operation, the refrigerant drawn into the compressor 100 is compressed by the compressor 100 and discharged in a high-temperature, high-pressure gas state. The high-temperature, high-pressure gas refrigerant discharged from the compressor 100 passes through the flow switching device 112 and flows into the outdoor heat exchanger 113, which functions as a condenser. In the outdoor heat exchanger 113, the refrigerant exchanges heat with outdoor air sent by the outdoor blower 114, condensing and liquefying. The condensed liquid refrigerant flows into the expansion section 115, where it expands and is decompressed to become a low-temperature, low-pressure, two-phase gas-liquid refrigerant. The two-phase gas-liquid refrigerant then flows into the indoor heat exchanger 116, which functions as an evaporator. In the indoor heat exchanger 116, the refrigerant exchanges heat with indoor air sent by the indoor blower 117, evaporating and gasifying. At this time, the indoor air is cooled, and cooling is performed in the room. The evaporated refrigerant in a low-temperature, low-pressure gas state passes through the flow switching device 112 and is drawn into the compressor 100.
[0015] (Operation Mode, Heating Operation) Next, the heating operation will be described. In the heating operation, the refrigerant drawn into the compressor 100 is compressed by the compressor 100 and discharged in a high-temperature, high-pressure gas state. The high-temperature, high-pressure gas refrigerant discharged from the compressor 100 passes through the flow switching device 112 and flows into the indoor heat exchanger 116, which functions as a condenser. In the indoor heat exchanger 116, the refrigerant condenses and liquefies through heat exchange with indoor air sent by the indoor blower 117. This heats the indoor air, providing heating in the room. The condensed liquid refrigerant flows into the expansion section 115, where it expands and decompresses to become a low-temperature, low-pressure, two-phase gas-liquid refrigerant. The two-phase gas-liquid refrigerant then flows into the outdoor heat exchanger 113, which functions as an evaporator. In the outdoor heat exchanger 113, the refrigerant exchanges heat with outdoor air sent by the outdoor blower 114, evaporating and gasifying. The evaporated refrigerant in a low-temperature, low-pressure gas state passes through the flow switching device 112 and is drawn into the compressor 100 .
[0016] The refrigeration cycle apparatus 110 does not necessarily have to include the flow path switching device 112. In this case, the refrigeration cycle apparatus 110 becomes a dedicated cooling or heating apparatus. The refrigeration cycle apparatus 110 can be applied to air conditioners, refrigerators, freezers, etc.
[0017] FIG. 2 is a cross-sectional view showing a compressor 100 according to a first embodiment. The compressor 100 is, for example, a scroll compressor, and is one of the components of a refrigeration cycle used in a refrigerator, a freezer, an air conditioner, a refrigeration system, a water heater, or the like. The compressor 100 draws in and compresses a refrigerant circulating through a refrigeration cycle, and discharges the refrigerant in a high-temperature, high-pressure state. As shown in FIG. 2 , the compressor 100 includes a shell 1 forming an outer shell, a main frame 2 fixed to the inner wall surface of the shell 1, a compression mechanism 3 that compresses the refrigerant, and an electric motor 6 that drives the compression mechanism 3. The compressor 100 also includes a rotating shaft 7 that connects the compression mechanism 3 and the electric motor 6. In the following description, the direction in which the rotating shaft 7 extends is referred to as the axial direction, and the direction perpendicular to the axial direction is referred to as the radial direction.
[0018] The shell 1 is made of a conductive material such as metal and is formed into a cylindrical shape with an enclosed space. The shell 1 houses a main frame 2, a compression mechanism 3, an electric motor 6, and a rotating shaft 7. The shell 1 has a low-pressure shell structure in which the electric motor 6 is located in a space filled with refrigerant drawn in from a suction pipe 13, for example.
[0019] The shell 1 is composed of a cylindrical main shell 1a, a substantially hemispherical upper shell 1b that closes the top opening of the main shell 1a, and a substantially hemispherical lower shell 1c that closes the bottom opening of the main shell 1a. The upper shell 1b and the lower shell 1c are each fixed to the main shell 1a by welding or the like. The shell 1 is supported by a fixing base 1d that is fixed to the lower shell 1c.
[0020] The inner wall surface of the main shell 1a has a first inner wall surface 10a with a large diameter formed at the upper end, and a second inner wall surface 10b formed below the first inner wall surface 10a and with a smaller diameter than the first inner wall surface 10a. A step 11 formed by the lower end of the first inner wall surface 10a and the upper end of the second inner wall surface 10b functions as a positioning portion for the main frame 2.
[0021] The main shell 1a is provided with a suction pipe 13 for drawing refrigerant into the shell 1, and a power supply unit 19 for supplying power to the compressor 100. The suction pipe 13 is connected by brazing or the like with a portion inserted into a hole formed in the side wall of the main shell 1a. The suction pipe 13 communicates with the low-pressure space 16b within the shell 1. The power supply unit 19 includes a cover 19a, a power supply terminal 19b, and a wiring 19c. The power supply terminal 19b is a metal member, and one end is surrounded by the cover 19a and the other end is located inside the main shell 1a. The wiring 19c has one end connected to the power supply terminal 19b and the other end connected to the electric motor 6.
[0022] A discharge pipe 14 that discharges the compressed refrigerant from the shell 1 is connected to the upper shell 1b. The discharge pipe 14 is connected by brazing or the like with a portion of the pipe inserted into a hole formed in the upper part of the upper shell 1b. An oil reservoir 18 that stores refrigerating machine oil is provided at the inner bottom of the shell 1. An injection pipe 12 that injects the refrigerant into the compression chamber 30 is also connected to the upper shell 1b.
[0023] As shown in FIG. 2 , the main frame 2 is a cylindrical metal frame that tapers gradually downward and supports the orbiting scroll 5 so that it can orbit freely. The center of the main frame 2 is an axial hole through which the rotary shaft 7 passes. The outer circumferential surface of the main frame 2 is fixed to the inner wall surface of the main shell 1 a, for example, by shrink fitting. An annular flat surface 20 is formed on the upper surface of the main frame 2. A ring-shaped thrust plate 25 made of a steel plate material such as valve steel is disposed on the flat surface 20. The thrust plate 25 functions as a thrust sliding surface for the main frame 2 and supports the thrust load of the compression mechanism 3.
[0024] 2, a housing portion 21 is formed inside the main frame 2. The main frame 2 is provided with a main bearing portion 22 that supports the rotating shaft 7. The housing portion 21 is formed on the upper side of the main frame 2. The main bearing portion 22 is provided on the lower side of the main frame 2.
[0025] 2, the accommodation portion 21 is formed so that the inner diameter decreases in stages downward. The accommodation portion 21 has a stepped portion located on the flat surface 20 side which serves as an Oldham accommodation portion 21a, and a stepped portion located on the main bearing portion 22 side which serves as a bushing accommodation portion 21b. A pair of keyways is formed in the Oldham accommodation portion 21a and part of the flat surface 20 so as to face each other across the shaft hole of the main frame 2.
[0026] 2, the main frame 2 is formed with an oil return hole 23 penetrating from the inside to the outside. The oil return hole 23 is connected to the bushing accommodation portion 21b. An oil return pipe 24 is inserted into and fixed in the oil return hole 23. The oil return pipe 24 is provided to return refrigeration oil accumulated in the accommodation portion 21 to the oil reservoir 18 provided in the lower shell 1c. The number of oil return holes 23 and oil return pipes 24 is not limited to one, and multiple return holes 23 and oil return pipes 24 may be provided.
[0027] As shown in Fig. 2, the fixed scroll 4 has a disk-shaped fixed base plate 4a and a fixed spiral protrusion 4b formed on the lower surface of the fixed base plate 4a. The orbiting scroll 5 has a disk-shaped oscillating base plate 5a and an orbiting spiral protrusion 5b formed on the upper surface of the oscillating base plate 5a and meshing with the fixed spiral protrusion 4b. The orbiting scroll 5 is installed eccentrically with respect to the fixed scroll 4. The fixed spiral protrusion 4b of the fixed scroll 4 and the orbiting spiral protrusion 5b of the orbiting scroll 5 combine to form a compression chamber 30 that compresses the refrigerant.
[0028] The fixed scroll 4 is made of metal such as cast iron, etc. The fixed scroll 4 has a fixed base plate 4a fixed to the upper part of the main frame 2 by, for example, bolting.
[0029] A discharge port 40 is formed in the center of the fixed base plate 4a, and discharges the compressed, high-temperature, high-pressure refrigerant. A chamber 15 is disposed on the upper surface of the fixed scroll 4, and has a discharge hole 15a that communicates with the discharge port 40. A discharge valve 17 that opens and closes the discharge hole 15a depending on the refrigerant pressure is screwed into the chamber 15. The discharge valve 17 opens the discharge hole 15a when the refrigerant in the compression chamber 30 that communicates with the discharge port 40 reaches a predetermined pressure. The compressed, high-temperature, high-pressure refrigerant is discharged from the discharge port 40 into the high-pressure space 16a at the top of the fixed scroll 4, passes through the discharge pipe 14, and is discharged to the outside of the shell 1.
[0030] 2, a fixed groove (not shown) is formed at the tip of the fixed spiral protrusion 4b along the spiral direction, and a fixed tip seal (not shown) made of, for example, hard plastic is inserted into this fixed groove. The radial width of the fixed groove is configured to be larger than the radial width of the fixed tip seal (not shown).
[0031] The orbiting scroll 5 is made of a metal such as aluminum. As shown in Fig. 2, the orbiting scroll 5 revolves without rotating relative to the fixed scroll 4 due to an Oldham ring 54 that prevents rotation. The surface of the orbiting base plate 5a on the side where the orbiting spiral protrusion 5b is not formed (the lower surface in the illustrated example) acts as an orbiting scroll thrust bearing surface.
[0032] A cylindrical boss portion 51 is provided at the center of the thrust bearing surface of the orbiting scroll. A rocking bearing that rotatably supports a slider 80 of a bushing 8 (described later) is provided on the inner peripheral surface of the boss portion 51. The rocking bearing is a so-called journal bearing. The rocking bearing is provided so that its central axis is parallel to the central axis of the rotating shaft 7. The orbiting scroll 5 revolves on the thrust sliding surface of the main frame 2 as an eccentric shaft portion 71 (described later) of the rotating shaft 7 inserted into the boss portion 51 rotates.
[0033] 2, a groove (not shown) is formed at the tip of the oscillating spiral protrusion 5b along the spiral direction, and a tip seal (not shown) made of, for example, hard plastic is inserted into the groove so as to be movable in the axial direction. The radial width of the groove is larger than the radial width of the tip seal.
[0034] As shown in Fig. 2, a pair of Oldham grooves 53 are formed on the thrust bearing surface of the orbiting scroll so as to face each other across the boss portion 51. The Oldham grooves 53 are oval key grooves. The pair of Oldham grooves 53 are arranged so that the line connecting them is perpendicular to the line connecting the key grooves of the main frame 2.
[0035] The Oldham ring 54 includes a ring portion and a key portion. The ring portion is annular and is provided in the Oldham receiving portion 21 a of the main frame 2. Two key portions are provided on each of the lower and upper surfaces of the ring portion. The key portion provided on the lower surface of the ring portion is received in the key groove of the main frame 2, and the key portion provided on the upper surface of the ring portion is received in the Oldham groove 53 of the orbiting scroll 5. The position of the orbiting spiral protrusion 5 b of the orbiting scroll 5 in the rotational direction is determined by aligning the Oldham groove 53 of the orbiting scroll 5 with the key portion of the Oldham ring 54. In other words, the Oldham ring 54 positions the orbiting scroll 5 relative to the main frame 2, and determines the phase of the orbiting spiral protrusion 5 b relative to the main frame 2.
[0036] The compression chambers 30 are sealed by contact between the fixed-side tip seals provided at the tips of the fixed spiral protrusions 4 b and the oscillating base plate 5 a, and by contact between the oscillating-side tip seals provided at the tips of the oscillating spiral protrusions 5 b and the fixed base plate 4 a. The compression chambers 30 are made up of a plurality of compression chambers 30 whose volumes decrease from the outside to the inside in the radial direction of the scroll.
[0037] The refrigerant may be, for example, a halogenated hydrocarbon having a carbon-carbon double bond, a halogenated hydrocarbon not having a carbon-carbon double bond, a natural refrigerant, or a mixture thereof. Examples of halogenated hydrocarbons having a carbon-carbon double bond include HFO refrigerants such as R1234yf (CFCF=CH), R1234ze (CFCH=CHF), or R1233zd (CFCH=CHCl). Examples of halogenated hydrocarbons not having a carbon-carbon double bond include HFC refrigerants such as R32 (CHF), R41 (CHF), R125 (CHF), R134a (CHFCF), R143a (CFCH), R410A (R32 / R125), or R407C (R32 / R125 / R134a). Examples of refrigerants include a mixture of R32 (difluoromethane) and R41, which are represented by CHF. Natural refrigerants include ammonia (NH), carbon dioxide (CO), propane (C3H8), propylene (C3H6), butane (C4H10), or isobutane (CH(CH3)3). Desirably, the refrigerant has zero ozone depletion potential and a low GWP.
[0038] As shown in Fig. 2, the electric motor 6 drives the compression mechanism 3 connected via a rotating shaft 7. The electric motor 6 has an annular stator 6a fixedly supported on the inner wall surface of the shell 1 by shrink fitting or the like, and a rotor 6b rotatably attached opposite the inner surface of the stator 6a. The stator 6a has a configuration in which a winding 64 is wound around an iron core 62 made of, for example, a plurality of laminated electromagnetic steel sheets via an insulating layer, and is formed in a ring shape in a plan view. The rotor 6b has a configuration in which a permanent magnet is built inside the iron core made of a plurality of laminated electromagnetic steel sheets, and has a through-hole that passes through the center in the vertical direction.
[0039] Fig. 3 is a top cross-sectional view showing a stator 6a according to the first embodiment. In the first embodiment, the stator 6a is wound using a concentrated winding method in which wire is wound in a concentrated manner around one tooth 63. As shown in Fig. 3, the stator 6a has an annular iron core 62, a plurality of teeth 63 extending inward from the iron core 62, and a coil made up of windings 64 wound around each tooth 63. Note that spaces called slots 65 are formed between each pair of windings 64.
[0040] 4 is a diagram showing coil ends 61 according to embodiment 1. Coil ends 61 are portions that protrude from both ends of annular core 62, and are located above the upper end of boundary portion 250, i.e., in large diameter portion 300. Conventionally, the insulation distance between the coil ends and the shell has been short, but in embodiment 1, boundary portion 250 ensures a large insulation distance between coil ends 61 and shell 1.
[0041] As shown in Figure 2, the rotating shaft 7 is a rod-shaped member made of metal. The rotating shaft 7 includes a main shaft portion 70 and an eccentric shaft portion 71. The main shaft portion 70 is a shaft that constitutes the main portion of the rotating shaft 7 and is disposed within the shell 1 so that its central axis coincides with the central axis of the main shell 1a. The main shaft portion 70 is fixed to a through-hole in the center of the rotor 6b by shrink fitting or the like. The main shaft portion 70 is rotatably supported by a main bearing portion 22 provided in the center of the main frame 2 and a sub-bearing portion 90 provided in the center of a sub-frame 9 that is fixed to the lower part of the shell 1 by welding or the like.
[0042] The eccentric shaft portion 71 is provided at the upper end of the main shaft portion 70 so that its central axis is eccentric with respect to the central axis of the main shaft portion 70. The eccentric shaft portion 71 is connected to the orbiting scroll 5 via a bushing 8, which is a metal member such as iron, and is rotatably supported by a boss portion 51 of the orbiting scroll 5. The rotating shaft 7 rotates in conjunction with the rotation of the rotor 6b, causing the orbiting scroll 5 to orbit via the eccentric shaft portion 71. An oil passage 72 is provided inside the main shaft portion 70 and the eccentric shaft portion 71 along the axial direction, penetrating to both end surfaces of the rotating shaft 7 in the axial direction.
[0043] 2, the bushing 8 includes a slider 80 and a balance weight 81a. The slider 80 is a cylindrical member formed with a flange, and is rotatably inserted into the boss portion 51. The eccentric shaft portion 71 is inserted inside the slider 80. In other words, the slider 80 is interposed between the orbiting scroll 5 and the eccentric shaft portion 71, and makes the orbiting radius of the orbiting scroll 5 variable, and also supports the orbiting scroll 5 to allow the orbiting scroll 5 to revolve.
[0044] The balance weight 81a is provided to offset the centrifugal force of the orbiting scroll 5 generated by the orbiting motion. The balance weight 81a is annular and formed in a generally C-shape in plan view on the side opposite the direction of the centrifugal force acting on the orbiting scroll 5. In the compressor 100, the balance weight 81a can reduce the pressure of the orbiting scroll protrusion 5b against the fixed scroll protrusion 4b. The balance weight 81a is fixed to the flange of the slider 80, for example, by shrink fitting. The balancer 82 is attached to offset imbalance caused by the orbiting motion of the orbiting scroll 5 and is a cylindrical weight with openings at the top and bottom. The balancer cover 83 prevents refrigeration oil from splashing into the shell 1 due to rotation of the balancer 82 and is shaped to surround the top and side surfaces of the balancer 82. Here, the open end of the balancer cover 83 is located opposite the stator 6a. This is because the size of the electric motor 6 is smaller than that of the compression mechanism 3. Oil rising of refrigeration oil is likely to occur due to the refrigeration oil being blown up as it passes through the space between the rotor 6b and the stator 6a. In the first embodiment, the open end of the balancer cover 83 is positioned opposite the stator 6a, so that the balancer cover 83 can capture the oil that is blown up. Therefore, oil rising can be suppressed.
[0045] The sub-frame 9 is a metal frame. As shown in Fig. 2, the sub-frame 9 is provided with an auxiliary bearing 90 and an oil pump 91. The auxiliary bearing 90 is a ball bearing provided in the center of the sub-frame 9. The oil pump 91 is a pump for sucking up refrigeration oil stored in the oil reservoir 18 of the shell 1, and is provided below the auxiliary bearing 90.
[0046] Refrigerant oil is stored in an oil reservoir 18. The refrigerant oil is pumped up by an oil pump 91 and passes through an oil passage 72 in the rotating shaft 7 to reduce wear between mechanically contacting parts such as the compression mechanism 3, and to improve temperature regulation and sealing of sliding parts. A suitable refrigerant oil has excellent lubrication properties, electrical insulation properties, stability, refrigerant solubility, and low-temperature fluidity, as well as a moderate viscosity. Examples of refrigerant oils that can be used include naphthenic, polyol ester (POE), polyvinyl ether (PVE), and polyalkylene glycol (PAG) oils.
[0047] Next, the operation of the compressor 100 will be described. When the power supply unit 19 is energized, the rotor 6b of the electric motor 6 rotates. Accordingly, the rotary shaft 7 fixed to the rotor 6b is driven to rotate. When the rotary shaft 7 is driven to rotate, the orbiting scroll 5 of the compression mechanism 3 is restricted from rotating by the Oldham ring 54 and performs an orbiting motion.
[0048] As the compression mechanism 3 is driven, refrigerant is sucked into the shell 1 through the suction pipe 13 and taken into the compression chamber 30. The compression chamber 30 that has taken in the refrigerant reduces its volume while moving from the outer periphery toward the center as the orbiting scroll 5 swings, compressing the refrigerant. The refrigerant compressed in the compression chamber 30 is discharged from the discharge port 40 provided in the fixed scroll 4 into the high-pressure space 16a and then discharged to the outside of the shell 1 through the discharge pipe 14.
[0049] During operation of the compressor 100, refrigeration oil is supplied to each sliding part of the compression mechanism 3. Specifically, when the rotating shaft 7 is driven to rotate, the oil pump 91 pumps up refrigeration oil stored in the oil sump 18 of the shell 1. The pumped refrigeration oil flows into an upstream opening of an oil passage 72 formed in the rotating shaft 7 and flows out from a downstream opening. The refrigeration oil that flows out from the downstream opening of the oil passage 72 flows into the inner space of the boss 51. A portion of the refrigeration oil that flows into the inner space of the boss 51 lubricates the rocking bearing. A portion of the refrigeration oil that lubricates the rocking bearing is supplied to the thrust plate 25 and then flows into the compression mechanism 3 to seal the compression chamber 30. The remainder of the refrigeration oil that lubricates the rocking bearing lubricates the main shaft 70 and other parts before returning to the oil sump 18.
[0050] When the orbiting scroll 5 is performing an orbiting motion, the fixed-side tip seal is pressed against the orbiting base plate 5a of the orbiting scroll 5 and slides due to the pressure difference between adjacent compression chambers 30. Similarly, the orbiting-side tip seal is pressed against the fixed base plate 4a of the fixed scroll 4 and slides due to the pressure difference between adjacent compression chambers 30. This pressure difference is the pressure difference between the compression chamber 30 on the center side of the orbiting scroll 5 and the compression chamber 30 one chamber radially outward from that compression chamber 30.
[0051] The fixed-side tip seal and the swing-side tip seal are also pressed radially outward due to this pressure difference. As a result, the fixed-side tip seal is positioned radially outward within the fixed-side groove, with its radially outer side surface contacting the side surface of the fixed-side groove on the same side. The swing-side tip seal is also positioned radially outward within the swing-side groove, with its radially outer side surface contacting the side surface of the swing-side groove on the same side.
[0052] As described above, the fixed-side tip seal and the swing-side tip seal are pressed against the opposing base plates, thereby sealing the compression chambers 30 and preventing leakage of compressed refrigerant between adjacent compression chambers 30. At this time, the greater the amount of refrigeration oil taken into the compression chambers 30, the better the sealing performance.
[0053] (Explanation of Shell 1) FIG. 5 is a top view showing the shell 1 according to the first embodiment, and FIG. 6 is a side cross-sectional view showing the shell 1 according to the first embodiment. FIG. 6 is a cross-sectional view taken along the line B-B in FIG. 5. Next, the structure of the shell 1 will be described in detail. As shown in FIGS. 5 and 6, the shell 1 has a small diameter portion 200, a large diameter portion 300, and a boundary portion 250. The small diameter portion 200 faces at least a portion of the outer periphery of the electric motor 6. The large diameter portion 300 faces the outer periphery of the compression mechanism 3 and has a larger diameter than the small diameter portion 200. Specifically, the outer diameter of the large diameter portion 300 located at the upper part of the main shell 1a of the shell 1 is larger than the outer diameter of the small diameter portion 200 located at the lower part of the main shell 1a. In other words, the outer diameter of the large diameter portion 300 is greater than the outer diameter of the small diameter portion 200.
[0054] As shown in FIG. 2 , a boundary 250 between the small diameter portion 200 and the large diameter portion 300 faces the outer periphery of the electric motor 6. The boundary 250 is inclined. The small diameter portion 200 is located at the shrink-fit portion 150 of the shell 1 to which the stator 6a is shrink-fitted, and the boundary 250 is spaced apart from the outer periphery of the stator 6a. The lower end of the boundary 250 is connected at an angle relative to the stator 6a. That is, the stator 6a has a portion fixed to the small diameter portion 200 and a portion not fixed to either portion. When the stator 6a is fixed by shrink fitting, the fixed portion may cause the stator core to deform due to the shrink fitting, reducing the efficiency of the electric motor 6 (motor). In contrast, in the first embodiment, the existence of a portion not fixed to either portion can suppress a reduction in the efficiency of the electric motor 6 (motor). The portion of the stator 6a that is fixed to the small diameter portion 200 and the portion that is not fixed to the small diameter portion 200 depend on the shrink fit required to hold the stator 6a. However, it is sufficient if the portion that is fixed to the small diameter portion 200 is about half or more of the total length (height) of the stator 6a, and the remaining portion can be the unfixed portion.
[0055] The main shell 1a extends upward from the lowest part without changing its diameter, then extends obliquely upward from the shrink-fitted part 150 while gradually increasing its diameter, and then extends upward again after reaching a predetermined diameter. As shown in Figure 2, the large diameter part 300 includes a part to which the suction pipe 13 is connected. That is, the suction pipe 13 is provided in the large diameter part 300. The boundary part 250 is not limited to an inclined shape, and may be crank-shaped.
[0056] The thickness of the shell 1 has the following relationship: thickness of the small diameter portion 200 > thickness of the boundary portion 250 > thickness of the large diameter portion 300. Here, the inner diameter of the large diameter portion 300 is greater than 100% and not greater than 115% of the inner diameter of the small diameter portion 200. The diameters of the fixed scroll 4, the orbiting scroll 5, and the main frame 2 located in portions facing the large diameter portion 300 are also large to match the diameter of the large diameter portion 300. Note that the sizes of the electric motor 6 and the subframe 9 located in portions facing the small diameter portion 200 remain unchanged.
[0057] The compressor 100 may also be equipped with a unit. The unit has various uses. The unit piping of the unit is disposed adjacent to the small diameter portion 200. A space is formed outside the small diameter portion 200 and below the large diameter portion 300. By providing the unit piping in this space, the unit piping does not get in the way. Therefore, the space can be used effectively when the unit is mounted.
[0058] According to the first embodiment, the shell 1 has a large diameter portion 300 that faces the outer periphery of the compression mechanism 3 and has an outer diameter larger than the small diameter portion 200 that faces at least a portion of the outer periphery of the electric motor 6. This eliminates the need to increase the size of components other than the compression mechanism 3, thereby reducing costs. Furthermore, because a frameless structure is not employed, the fixed scroll 4 does not need to be fixed to the shell 1 by shrink fitting. This facilitates assembly. By enlarging the scroll housing portion, a space capable of accommodating a large-capacity scroll can be secured. This allows for a larger stroke volume and makes it possible to accommodate low-density refrigerants. Furthermore, because the electric motor 6 and subframe 9 do not need to be enlarged, the existing electric motor 6 and subframe 9 can be reused, and the cost of enlarging components is eliminated. In this way, increasing the stroke volume is inexpensive and facilitates assembly.
[0059] The large-diameter portion 300 also includes a portion connected to the suction pipe 13. This allows for an expansion of the space below the main frame 2 where the suction pipe 13 is installed. This allows for a larger refrigerant intake space, improving compression efficiency. Furthermore, the refrigerant flow rate can be reduced, reducing oil spills due to refrigerant suction. Furthermore, the small-diameter portion 200 is located at the shrink-fit portion 150, and the boundary portion 250 is spaced apart from the outer periphery of the stator 6a. By not shrink-fitting a portion of the stator 6a, the amount of deformation of the stator 6a can be reduced. This improves the efficiency of the electric motor 6. Furthermore, the fixed scroll 4 is fixed to the shell 1 by tightening bolts, as in the conventional configuration. This does not impair assembly.
[0060] Furthermore, the thickness of the shell 1 satisfies the relationship: thickness of the small diameter portion 200 > thickness of the large diameter portion 300. When the shell 1 is manufactured by tube expansion and the outer diameter of the large diameter portion 300 is greater than the outer diameter of the small diameter portion 200, the thickness satisfies the relationship: thickness of the small diameter portion 200 > thickness of the large diameter portion 300. Furthermore, the thickness of the shell 1 satisfies the relationship: thickness of the small diameter portion 200 > thickness of the boundary portion 250 > thickness of the large diameter portion 300. Because the small diameter portion 200 is thicker than the boundary portion 250 and the large diameter portion 300, the holding force due to shrink fitting can be ensured even with a small shrink-fitting allowance. That is, in the first embodiment, in addition to reducing the portion of the stator 6a that deforms as described above, the efficiency of the electric motor 6 can be further improved by reducing the shrink-fitting allowance of the stator 6a.
[0061] If the fixed spiral protrusion 4b and the oscillating spiral protrusion 5b are made larger to realize the large diameter portion 300, vibration (swaying) during operation will increase. In the present embodiment 1, the oscillating scroll 5 is made of aluminum, which is lighter than iron, so that vibration (swaying) during operation can be suppressed.
[0062] As described above, the suction pipe 13 is located in the large-diameter portion 300. This increases the space into which the refrigerant is drawn, slowing the refrigerant flow rate and facilitating the separation of refrigerant oil from the refrigerant before it enters the suction port. This reduces the risk of refrigerant oil being drawn into the compression mechanism 3 and discharged through the discharge pipe 14, a phenomenon that often occurs when the rotational frequency increases. Furthermore, the oil separated from the refrigerant falls by its own weight into the space between the boundary portion 250 and the stator 6a. It then smoothly falls into the oil reservoir 18 through the gap between the stator 6a and the small-diameter portion 200 along the boundary portion 250, which is connected at an angle to the stator 6a. Furthermore, the space between the boundary portion 250 and the stator 6a allows the refrigerant and refrigerant oil to cool the outer surface of the stator 6a, lowering the temperatures of the stator 6a, the rotor 6b, and the magnets inside the rotor 6b.
[0063] Second Embodiment Fig. 7 is a cross-sectional view showing a compressor 100 according to a second embodiment. The second embodiment differs from the first embodiment in that the shell 1 has a second large diameter portion 400. In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals and their description will be omitted, and the description will focus on the differences from the first embodiment.
[0064] As shown in Figure 7, the main shell 1a and lower shell 1c of the shell 1 have second large diameter portions 400 that are larger in diameter than the small diameter portions 200. Specifically, the diameter of the second large diameter portion 400 located at the lower part of the main shell 1a is larger than the diameter of the small diameter portion 200 located at the center of the main shell 1a. The lower shell 1c of the shell 1 also has a large diameter to match the larger diameter of the lower part of the main shell 1a. In this way, the lower part of the main shell 1a, which has a larger diameter, and the lower shell 1c, which also has a larger diameter, are fixed together.
[0065] FIG. 8 is a side cross-sectional view showing the shell 1 according to the second embodiment. As shown in FIG. 8 , the second boundary 350 between the small diameter portion 200 and the second large diameter portion 400 is inclined. Here, the small diameter portion 200 is located at the shrink-fit portion 150 of the shell 1 to which the stator 6a is shrink-fitted, and the second boundary 350 is spaced apart from the outer periphery of the stator 6a. That is, in the stator 6a according to the second embodiment, portions not fixed to the small diameter portion 200 are located opposite the boundary 250 and the second boundary 350. This further reduces the portion of the stator core that is deformed, thereby further suppressing a decrease in the efficiency of the electric motor 6. Note that the second boundary 350 is not limited to an inclined shape and may be crank-shaped.
[0066] The main shell 1a extends upward from the lowest part without changing its diameter, then extends obliquely upward while decreasing in diameter toward the shrink-fitted portion 150 of the shell 1, and extends upward again after reaching the shrink-fitted portion 150. Thereafter, the main shell 1a extends obliquely upward from the shrink-fitted portion 150 while gradually increasing in diameter, and once it reaches a predetermined diameter, extends upward again.
[0067] The thickness of the shell 1 has the following relationship: thickness of the small diameter portion 200 > thickness of the second boundary portion 350 > thickness of the second large diameter portion 400. The diameter of the subframe 9 located in the portion facing the second large diameter portion 400 is also large to match the diameter of the second large diameter portion 400. The size of the electric motor 6 located in the portion facing the small diameter portion 200 remains unchanged.
[0068] An example of dimensions and the like in the second embodiment will now be described. The thickness of the large diameter portion 300 is 5.0 mm, the thickness of the small diameter portion 200 is 5.7 mm, and the thickness of the second large diameter portion 400 is 4.5 mm. The large diameter portion 300 protrudes 13 mm outward beyond the small diameter portion 200. The angle between the boundary portion 250 and the small diameter portion 200 is 20 degrees, and the angle between the second boundary portion 350 and the small diameter portion 200 is 25 degrees. The angles between the boundary portion 250 and the large diameter portion 300 and the second large diameter portion 400 are 45 degrees or less, and preferably 30 degrees or less.
[0069] According to the second embodiment, the main shell 1a and the lower shell 1c of the shell 1 have a second large-diameter portion 400 having a diameter larger than the small-diameter portion 200. Therefore, there is no need to increase the size of components other than the compression mechanism 3, resulting in lower costs. Furthermore, because a frameless structure is not employed, there is no need to fix the fixed scroll 4 to the shell 1 by shrink fitting. Therefore, assembly is easy. By enlarging the scroll housing portion, space can be secured to accommodate a large-capacity scroll. This allows for a larger stroke volume, making it possible to accommodate low-density refrigerants. Furthermore, there is no need to increase the size of the electric motor 6, so the existing electric motor 6 can be reused, and there is no cost associated with increasing the size of components. In this way, increasing the stroke volume is inexpensive and assembly is easy.
[0070] The large-diameter portion 300 also includes a portion connected to the suction pipe 13. This allows for an expansion of the lower space of the main frame 2 where the suction pipe 13 is installed. This allows for a larger refrigerant intake space, improving compression efficiency. Furthermore, this allows for a lower refrigerant flow rate, reducing oil spills due to refrigerant suction. Furthermore, the small-diameter portion 200 is located at the shrink-fit portion 150, and the boundary portion 250 and the second boundary portion 350 are spaced apart from the outer periphery of the stator 6a. By not shrink-fitting a portion of the stator 6a, the amount of deformation of the stator 6a can be reduced. This improves the efficiency of the electric motor 6. Furthermore, the fixed scroll 4 is fixed to the shell 1 by tightening bolts, as in the conventional configuration. This does not impair assembly.
[0071] Furthermore, by increasing the diameter of the lower shell 1c, the amount of refrigeration oil that can be stored in the oil reservoir 18 of the lower shell 1c can be increased. As a result, when the compressor 100 is installed in the outdoor unit 121, operation under an excessive oil level can be suppressed, thereby improving the performance of the refrigeration cycle apparatus 110. Note that the diameter of the large-diameter portion 300, which is the upper portion of the main shell 1a, and the diameter of the second large-diameter portion 400, which is the lower portion of the main shell 1a, may be the same or different. If they are different, the diameter of the large-diameter portion 300 may be adjusted to match the size of the spiral, and the diameter of the second large-diameter portion 400 may be adjusted according to the amount of refrigeration oil that can be stored in the oil reservoir 18. For example, the outer diameter of the large-diameter portion 300 may be greater than the outer diameter of the second large-diameter portion 400 and greater than the outer diameter of the shrink-fit portion 150.
[0072] Furthermore, the outer diameter of the large diameter portion 300 of the shell 1 may be larger than the outer diameter of the small diameter portion 200, and further, the outer diameter of the second large diameter portion 400 may be larger than the outer diameter of the large diameter portion 300. That is, the relationship may be such that the outer diameter of the second large diameter portion 400 > the outer diameter of the large diameter portion 300 > the outer diameter of the small diameter portion 200. The outer diameter of the large diameter portion 300 is set so as to be able to accommodate the fixed spiral protrusion 4b and the oscillating spiral protrusion 5b. The outer diameter of the second large diameter portion 400 should be as large as possible to suppress excessive oil flow.
[0073] The thickness of the shell 1 has the following relationship: thickness of the small diameter portion 200 > thickness of the large diameter portion 300 > thickness of the second large diameter portion 400. When the shell 1 is manufactured by tube expansion and the outer diameter of the second large diameter portion 400 > outer diameter of the large diameter portion 300 > outer diameter of the small diameter portion 200, the thickness relationship is as described above. In the case of a low-pressure shell structure, the thickness of the large diameter portion 300 (high-pressure portion) can be made thinner than that of the second large diameter portion 400 (low-pressure portion), thereby ensuring the pressure resistance of the shell 1. Therefore, in this second embodiment, a low-pressure shell is more suitable than a high-pressure shell.
[0074] DESCRIPTION OF SYMBOLS 1 Shell, 1a Main shell, 1b Upper shell, 1c Lower shell, 1d Fixed base, 2 Main frame, 3 Compression mechanism, 4 Fixed scroll, 4a Fixed base plate, 4b Fixed volute protrusion, 5 Swing scroll, 5a Swing base plate, 5b Swing volute protrusion, 6 Electric motor, 6a Stator, 6b Rotor, 7 Rotating shaft, 8 Bush, 9 Subframe, 10a First inner wall surface, 10b Second inner wall surface, 11 Step portion, 12 Injection pipe, 13 Suction pipe, 14 Discharge pipe, 15 Chamber, 15a Discharge hole, 16a High pressure space, 16b Low pressure space, 17 Discharge valve, 18 Oil reservoir, 19 Power supply portion, 19a Cover, 19b Power supply terminal, 19c Wiring, 20 Flat surface, 21 Housing portion, 21a Oldham accommodation portion, 21b bush accommodation portion, 22 main bearing portion, 23 oil return hole, 24 oil return pipe, 25 thrust plate, 30 compression chamber, 40 discharge port, 51 boss portion, 53 Oldham groove, 54 Oldham ring, 61 coil end, 62 iron core, 63 teeth, 64 winding, 65 slot, 70 main shaft portion, 71 eccentric shaft portion, 72 oil passage, 80 slider, 81a balance weight, 82 balancer, 83 balancer cover, 90 auxiliary bearing portion, 91 oil pump, 100 compressor, 110 refrigeration cycle device, 112 flow path switching device, 113 outdoor heat exchanger, 114 outdoor blower, 115 expansion portion, 116 indoor heat exchanger, 117 indoor blower, 121 outdoor unit, 122 Indoor unit, 123 refrigerant circuit, 124 refrigerant piping, 150 shrink-fit portion, 200 small diameter portion, 250 boundary portion, 300 large diameter portion, 350 second boundary portion, 400 second large diameter portion.
Claims
1. The outer shell and An electric motor is provided inside the shell, A rotating shaft attached to the electric motor and transmitting the rotational force of the electric motor, A compression mechanism that rotates in conjunction with the rotation of the aforementioned rotating shaft to compress the refrigerant, The shell comprises a suction pipe connected to the side of the shell through which refrigerant is drawn, The aforementioned shell is A small diameter portion facing at least a part of the outer circumference of the electric motor, Opposite the outer circumference of the compression mechanism, there is a large-diameter portion with a larger diameter than the small-diameter portion, It has a boundary portion located at the boundary between the small diameter portion and the large diameter portion, The thickness of the aforementioned shell is, The thickness of the small diameter portion > The thickness of the large diameter portion They are in a relationship, The aforementioned shell is Main shell and, An upper shell located above the main shell, It has a lower shell located below the main shell, The aforementioned main shell is It further has a second large-diameter portion that has a larger diameter than the small-diameter portion and the large-diameter portion, The thickness of the aforementioned shell is, The thickness of the small diameter portion > The thickness of the large diameter portion > The thickness of the second large diameter portion They are in a relationship Scroll compressor.
2. The aforementioned electric motor is, The stator fixed by shrink-fitting in the shrink-fitting portion of the aforementioned shell, The stator has a rotor provided on its inner circumference and which rotates together with the rotation shaft, The small diameter portion is located in the shrink-fit portion, The boundary portion and the outer circumference of the stator are spaced apart. The scroll compressor according to claim 1.
3. The lower end of the boundary portion is It is connected at an angle to the stator. The scroll compressor according to claim 2.
4. The stator is, The wire is wound using a concentrated winding method, where the wire is wrapped around it in a concentrated manner. The scroll compressor according to claim 2 or 3.
5. The stator is, The coil ends, which are the parts that protrude from both ends of the annular core, are located above the upper end of the boundary portion. The scroll compressor according to claim 2 or 3.
6. The compression mechanism is A fixed scroll that is fixed to the aforementioned shell, It comprises a swinging scroll that is installed eccentrically with respect to the fixed scroll, The oscillating scroll is made of aluminum. A scroll compressor according to any one of claims 1 to 3.
7. The inner diameter of the aforementioned large diameter portion is The inner diameter of the small diameter portion is greater than 100% and less than or equal to 115%. A scroll compressor according to any one of claims 1 to 3.
8. The aforementioned suction tube is The large diameter portion is provided A scroll compressor according to any one of claims 1 to 3.
9. The aforementioned shell is The electric motor is located in a space filled with refrigerant drawn in from the aforementioned suction pipe, forming a low-pressure shell structure. A scroll compressor according to any one of claims 1 to 3.
10. A scroll compressor according to any one of claims 1 to 3, The scroll compressor further comprises a unit mounted on the aforementioned scroll compressor, The unit piping of the aforementioned unit is Distended adjacent to the small diameter portion Refrigeration cycle device.