The stator of the electric motor, the electric motor, the compressor, and the refrigeration cycle device.

Abstract

This utility model relates to a stator of an electric motor, an electric motor, a compressor, and a refrigeration cycle device, which can improve the cooling efficiency of the electric motor to achieve high output. The stator of the electric motor has a stator core and windings. The stator core has a magnetic yoke, multiple teeth, and multiple slots. The magnetic yoke has slots and holes. The slots are continuous in the axial direction of the rotation axis of the electric motor, causing the outer peripheral surface of the magnetic yoke to be recessed to allow refrigerant to pass through. The holes are continuous in the axial direction and penetrate the magnetic yoke. In a vertical section of the stator core relative to the axial direction, the slots are positioned on an imaginary line that approximately bisects the teeth in the circumferential direction, and the holes are positioned at a position where the shortest distance between the opening edge of the hole and the inner peripheral surface of the magnetic yoke is greater than the shortest distance between the slot and the inner peripheral surface of the magnetic yoke.

Description

Technical Field

[0001] The present invention relates to a stator, an electric motor having the stator, a compressor having the electric motor, and a refrigeration cycle device having the compressor. Background Technology

[0002] For example, the electric motor used in a hermetic compressor has a generally cylindrical stator and a rotor that is rotatably mounted relative to the stator. The stator, for example, has a stator core and windings. The stator core consists of a generally cylindrical yoke and a plurality of teeth protruding radially inward from the yoke. The coils are wound around the teeth, which are spaced at predetermined intervals circumferentially on the yoke.

[0003] In recent years, there has been a demand for high output in electric motors. As one means to achieve this, in order to effectively utilize the winding area of ​​the coils in the stator, one example is to use a segmented iron core that divides the stator into multiple segments.

[0004] For example, the segmented iron core is designed such that the relative positions of the yoke and the teeth are such that wires can be wound around it in a configuration where multiple segmented iron cores are arranged. The yoke is the part of the stator that corresponds to the yoke, and the teeth are the part of the stator that corresponds to the teeth. As an example, the segmented iron core is formed such that the inner circumference of the yoke is perpendicular to the centerline of the teeth.

[0005] Furthermore, to achieve high output from the electric motor, efficient cooling is required. Therefore, a passage for coolant, such as refrigerant, to pass through is sometimes provided on the outer periphery of the stator. The larger the cross-sectional area of ​​this passage, the easier it is for the coolant to pass through, thus improving the motor's cooling efficiency. On the other hand, the outer periphery of the stator becomes, for example, the fitting surface relative to the sealed container when the stator is thermally press-fitted into the compressor's sealed container. Therefore, if a passage is provided on the outer periphery of the stator, the fitting surface relative to the sealed container will be reduced by an amount equivalent to the passage. Thus, the larger the passage in the stator, the easier it is to reduce the holding force of the stator relative to the sealed container when the stator is thermally press-fitted, leading to a decrease in compressor reliability. Additionally, even when the holding force of the stator relative to the sealed container is satisfied, the stress generated in the stator increases, which may lead to a decrease in efficiency due to the deterioration of the magnetic properties of the motor core.

[0006] Existing technical documents Patent documents Patent Document 1: Japanese Patent No. 7163948 Utility Model Content

[0007] This invention was made in view of the above circumstances, and its purpose is to provide a stator that can improve the cooling efficiency of the electric motor and achieve high output.

[0008] According to one embodiment, the stator of the electric motor includes a stator core and windings. The stator core is cylindrical, surrounding a rotor that is fixed to and rotates a rotating shaft. The windings are wound around the stator core. The stator core has a yoke, a plurality of teeth, and a plurality of slots. The yoke is cylindrical, concentrically surrounding the rotor. The plurality of teeth protrude radially inward from the yoke and are spaced apart circumferentially from it. The plurality of slots are formed between adjacent teeth in the circumferential direction and accommodate the windings. The yoke has slots and holes. The slots are continuous axially in the direction of the rotational shaft, causing the outer peripheral surface of the yoke to be recessed for refrigerant to pass through. The holes are continuous axially and extend through the yoke. In the vertical section of the stator core relative to the axial direction, the slot is positioned on an imaginary line that roughly bisects the tooth in the circumferential direction, and the hole is positioned at a position where the shortest distance between the opening edge of the hole and the inner circumferential surface of the yoke is greater than the shortest distance between the slot and the inner circumferential surface of the yoke.

[0009] The stator of the motor in the above embodiment can also be configured such that the stator core is divided into multiple segmented cores, each segmented core including a tooth and a portion of the yoke protruding from the tooth. Each of the multiple segmented cores has a contact surface that contacts other segmented cores adjacent in the circumferential direction. In the vertical cross-section, the shortest distance between the opening edge of the hole of the segmented core and the slot of the segmented core is shorter than the shortest distance between the opening edge of the hole and the contact surface of the segmented core.

[0010] The stator of the motor in the above embodiment can also be configured such that, in the vertical cross section, the slot is formed in a shape that is linearly symmetrical with respect to the imaginary line, and the holes are arranged in pairs on both sides of the imaginary line in a manner that is linearly symmetrical with respect to the imaginary line.

[0011] The stator of the motor in the above embodiment can also be configured such that, in the vertical cross section, the slot is extended into a second slot shape that is different from the first slot shape that is linearly symmetrical with respect to the imaginary line, and the second slot shape is formed to be continuously connected to a region corresponding to one of the paired holes.

[0012] The stator of the motor in the above embodiment can also be configured such that, in the vertical cross section, the second slot shape is formed as a continuous connection with a region corresponding to the leading side of the hole in the rotation direction of the rotating shaft among the paired holes.

[0013] The stator of the motor in the above embodiment can also be configured such that the slot portion has a continuous slot bottom in the axial direction, and in the vertical section, the inner circumferential surface of the yoke and the slot bottom of the slot portion are respectively perpendicular to the imaginary line.

[0014] According to the embodiment, the electric motor includes: a rotor; and the stator described above.

[0015] According to one embodiment, the compressor includes: a cylindrical sealed container; a compression mechanism that compresses the refrigerant inside the sealed container and discharges the compressed refrigerant into the sealed container; and the aforementioned electric motor that is housed in the sealed container and drives the compression mechanism.

[0016] The compressor in the above embodiments can also be configured such that the refrigerant is any one of R290, R454B, and R454C.

[0017] According to an embodiment, the refrigeration cycle device includes: a circulation loop for circulating the refrigerant and connected to a condenser, an expansion device, and an evaporator; and the aforementioned compressor connected to the circulation loop between the condenser and the evaporator. Attached Figure Description

[0018] Figure 1 This is a circuit diagram that roughly represents the structure of the air conditioner according to the first embodiment.

[0019] Figure 2 This is a schematic longitudinal sectional view of the compressor according to the first embodiment.

[0020] Figure 3 This is a diagram that roughly shows the electric motor of the first embodiment from above.

[0021] Figure 4 It is a general representation Figure 3 The diagram shows the structure of the segmented iron core of the electric motor, and a vertical sectional view of the segmented iron core relative to the axial direction.

[0022] Figure 5 This is a schematic diagram of the structure of the segmented core of the electric motor according to the second embodiment, shown as a vertical cross-sectional view of the segmented core relative to the axial direction.

[0023] Explanation of reference numerals in the attached figures 1…Air conditioner; 2…Compressor; 3…Four-way valve; 4…Outdoor heat exchanger; 401…Outdoor blower; 5…Expansion device; 6…Indoor heat exchanger; 601…Indoor blower; 7…Circulation loop; 10…Sealed container; 11…Compression mechanism; 12…Motor; 15…Rotating shaft; 33…Rotor; 34…Stator; 34a…Stator core; 34b…Divided core; 50…Yoke; 50a…Outer peripheral surface; 50b…Inner peripheral surface; 50c, 50d…End surface; 50e, 50f…Side surface; 51…Tooth; 51a, 51b…Side surface; 51c…Protruding end surface; 51d, 51e…End surface; 51f…Protrusion; 52…Slot; 53…Coil; 54, 70…Second passage (slot); 54a, 70a …bottom of the trough; 54b, 54c…trough wall; 55, 56…insulating components; 57b, 57c…partition wall; 58b…corresponding part of the partition; 60, 61, 62…hole; 60a…first face; 60b…second face; 60c…third face; 70b…face (trough wall); 100…oil separator; D41…shortest distance between the opening edge of the hole and the inner circumferential face of the yoke; D42…shortest distance between the bottom of the trough and the inner circumferential face of the yoke; D43…shortest distance between the opening edge of the hole and the bottom of the trough; D44…shortest distance between the opening edge of the hole and the side face of the yoke; D54…shortest distance between the edge of the trough and the side face of the yoke; L51…centerline of the tooth; O1…central axis of the sealed container. Detailed Implementation

[0024] (First Implementation) Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The application of the electric motor of the present invention is not particularly limited. In this embodiment, the case of an electric motor unit used in a rotary compressor (hereinafter referred to as compressor) of an air conditioner will be described as an example. The electric motor unit is the drive source for the compression mechanism unit that compresses the refrigerant in the compressor.

[0025] Figure 1 This is a refrigeration cycle circuit diagram of the air conditioner 1 according to this embodiment. The air conditioner 1 is a device that performs air conditioning through this refrigeration cycle, and is an example of a refrigeration cycle device. The air conditioner 1 includes a compressor 2, a four-way valve 3, an outdoor heat exchanger 4, an outdoor fan 401, an expansion device 5, an indoor heat exchanger 6, and an indoor fan 601 as its main components.

[0026] like Figure 1As shown, the refrigerant discharge side of compressor 2 is connected to the first port 3a of four-way valve 3. The second port 3b of four-way valve 3 is connected to outdoor heat exchanger 4. Outdoor heat exchanger 4 is connected to indoor heat exchanger 6 via expansion device 5. Indoor heat exchanger 6 is connected to the third port 3c of four-way valve 3. The fourth port 3d of four-way valve 3 is connected to the refrigerant suction side of compressor 2 via receiver 8. The refrigerant circulates in loop 7 from the discharge side of compressor 2 through outdoor heat exchanger 4, expansion device 5, indoor heat exchanger 6, and receiver 8 to the suction side. Any refrigerant can be used, but low-pressure refrigerants such as R290, R454B, and R454C are preferred.

[0027] For example, when the air conditioner 1 is operating in cooling mode, the four-way valve 3 switches so that the first port 3a is connected to the second port 3b, and the third port 3c is connected to the fourth port 3d. When the air conditioner 1 starts operating in cooling mode, the high-temperature, high-pressure gaseous refrigerant compressed by the compressor 2 is discharged into the circulation loop 7. The discharged gaseous refrigerant is guided through the four-way valve 3 to the outdoor heat exchanger 4, which functions as a condenser (radiator).

[0028] The gaseous refrigerant guided to the outdoor heat exchanger 4 condenses and transforms into a high-pressure liquid refrigerant through heat exchange with the air (external gas) drawn in by the outdoor fan 401. The high-pressure liquid refrigerant is then depressurized and transforms into a low-pressure gas-liquid two-phase refrigerant as it flows through the expansion device 5. This gas-liquid two-phase refrigerant is then guided to the indoor heat exchanger 6, which functions as an evaporator (heat absorber), and exchanges heat with the air (internal gas) drawn in by the indoor fan 601 as it flows through the indoor heat exchanger 6.

[0029] As a result, the gas-liquid two-phase refrigerant absorbs heat from the air and evaporates, transforming into a low-temperature, low-pressure gas-phase refrigerant. The air flowing through the indoor heat exchanger 6 is cooled by the latent heat of vaporization of the liquid-phase refrigerant and is delivered as cold air by the indoor fan 601 to the areas where air conditioning (cooling) is required.

[0030] The low-temperature, low-pressure gaseous refrigerant flowing through the indoor heat exchanger 6 is directed to the receiver 8 via the four-way valve 3. If incompletely evaporated liquid refrigerant is mixed in with the refrigerant, it is separated into liquid and gaseous refrigerant here. The low-temperature, low-pressure gaseous refrigerant separated from the liquid refrigerant is drawn from the receiver 8 into the compressor 2, where it is compressed again into high-temperature, high-pressure gaseous refrigerant and discharged into the circulation loop 7.

[0031] On the other hand, when the air conditioner 1 is operating in heating mode, the four-way valve 3 switches so that the first port 3a is connected to the third port 3c, and the second port 3b is connected to the fourth port 3d. When the air conditioner 1 starts operating in heating mode, the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 2 is guided to the indoor heat exchanger 6 via the four-way valve 3 to exchange heat with the air flowing through the indoor heat exchanger 6. In this case, the indoor heat exchanger 6 functions as a condenser.

[0032] As a result, the gaseous refrigerant flowing through the indoor heat exchanger 6 exchanges heat with the air (internal gas) drawn in by the indoor fan 601 and condenses, changing into a high-pressure liquid refrigerant. The air flowing through the indoor heat exchanger 6 is heated by the heat exchange with the gaseous refrigerant and is delivered as warm air by the indoor fan 601 to the areas where air conditioning (heating) is required.

[0033] The high-temperature liquid refrigerant flowing through the indoor heat exchanger 6 is guided to the expansion device 5, where it is depressurized and changes into a low-pressure gas-liquid two-phase refrigerant. This gas-liquid two-phase refrigerant is then guided to the outdoor heat exchanger 4, which functions as an evaporator, and evaporates by exchanging heat with the air (external gas) drawn in by the outdoor fan 401, changing into a low-temperature, low-pressure gas-phase refrigerant. The low-temperature, low-pressure gas-phase refrigerant after flowing through the outdoor heat exchanger 4 is drawn into the compressor 2 via the four-way valve 3 and the receiver 8, where it is again compressed into a high-temperature, high-pressure gas-phase refrigerant and discharged into the circulation loop 7.

[0034] In addition, in this embodiment, the air conditioner 1 can operate in either cooling mode or heating mode, but the air conditioner 1 may also be a dedicated cooling unit or a dedicated heating unit that can only operate in either cooling mode or heating mode.

[0035] Next, refer to Figure 2 The specific structure of the compressor 2 used in air conditioner 1 is described. Figure 2 This is a longitudinal sectional view that roughly represents the structure of compressor 2. (For example...) Figure 2 As shown, compressor 2 is a so-called longitudinal rotary compressor (rotary compressor), and its main components include a sealed container 10, a compression mechanism 11, and an electric motor 12. Furthermore, in the following description, based on the relative positional relationship between the compression mechanism 11 and the electric motor 12, which are arranged along the central axis O1 of the sealed container 10 (described later), the side containing the compression mechanism 11 is designated as "down," and the side containing the electric motor 12 is designated as "up." Additionally, the direction in which the central axis O1 extends is called the axial direction, and the direction connecting the center of the circle (a section perpendicular to this axial direction) to the circumference is called the radial direction.

[0036] The sealed container 10 has a cylindrical peripheral wall 10a and stands vertically relative to the mounting surface. The mounting surface is, for example, the base plate of the outdoor unit of the air conditioner 1. A refrigerant discharge pipe 10b is provided at the upper end of the sealed container 10. The discharge pipe 10b forms part of the circulation loop 7 and is connected to the first port 3a of the four-way valve 3 via the circulation loop 7. An oil reservoir 10c for storing lubricating oil I is provided at the lower part of the sealed container 10.

[0037] The compression mechanism 11 compresses the refrigerant inside the sealed container 10 and discharges the compressed refrigerant into the sealed container 10. The compression mechanism 11 is housed in the lower part of the sealed container 10 by being immersed in lubricating oil I. Figure 2 In the example shown, the compression mechanism 11 has a dual-cylinder structure, comprising a first cylinder 13, a second cylinder 14, a rotating shaft 15, a first roller 16, and a second roller 17 as its main elements. Furthermore, the number of cylinders in the compression mechanism is not limited to two; it can also be one or more.

[0038] The first cylinder 13 is fixed to the inner circumferential surface of the peripheral wall 10a of the sealed container 10. The second cylinder 14 is fixed to the lower surface of the first cylinder 13 via a partition plate 18.

[0039] A first bearing 20 is fixed above the first cylinder 13. The first bearing 20 covers the inner diameter portion of the first cylinder 13 from above and protrudes upwards from the first cylinder 13. The space enclosed by the inner diameter portion of the first cylinder 13, the partition plate 18, and the first bearing 20 constitutes the first cylinder chamber 21. The partition plate 18 corresponds to a sealing member defining the lower surface of the first cylinder chamber 21, and the first bearing 20 corresponds to a sealing member defining the upper surface of the first cylinder chamber 21.

[0040] A second bearing 22 is fixed below the second cylinder 14. The second bearing 22 covers the inner diameter of the second cylinder 14 from below and protrudes downwards from the second cylinder 14. The space enclosed by the inner diameter of the second cylinder 14, the partition plate 18, and the second bearing 22 constitutes the second cylinder chamber 23. The partition plate 18 corresponds to a sealing member defining the upper surface of the second cylinder chamber 23, and the second bearing 22 corresponds to a sealing member defining the lower surface of the second cylinder chamber 23. The first cylinder chamber 21 and the second cylinder chamber 23 are arranged concentrically with the central axis O1 of the sealed container 10.

[0041] The first cylinder chamber 21 and the second cylinder chamber 23 are connected to the receiver 8 via refrigerant suction pipes 25a and 25b. Suction pipes 25a and 25b form part of the circulation loop 7. The gaseous refrigerant separated from the liquid refrigerant in the receiver 8 is guided to the first cylinder chamber 21 and the second cylinder chamber 23 through the suction pipes 25a and 25b.

[0042] The rotating shaft 15 is located coaxially with the central axis O1 of the sealed container 10, and passes through the first cylinder chamber 21, the second cylinder chamber 23, and the partition plate 18. The rotating shaft 15 has a first journal 27a, a second journal 27b, and a pair of crank pin portions (eccentric portions) 28a and 28b. That is, the rotating shaft 15 is configured as a crankshaft. The first journal 27a is supported by the first bearing 20 and is rotatable. The second journal 27b is supported by the second bearing 22 and is rotatable.

[0043] Furthermore, the rotating shaft 15 has an extension 27c that extends coaxially from the first journal 27a. The extension 27c passes through the first bearing 20 and protrudes above the compression mechanism section 11. The rotor 33 of the electric motor 12, which will be described later, is fixed to the extension 27c by pressing or the like.

[0044] Eccentric portions 28a and 28b are located between the first journal 27a and the second journal 27b. The eccentric portions 28a and 28b are configured, for example, with a 180-degree phase difference in the circumferential direction relative to the central axis O1 of the sealed container 10, and their eccentricity relative to the central axis O1 is the same. One eccentric portion (hereinafter referred to as the first eccentric portion) 28a is housed in the first cylinder chamber 21. The other eccentric portion (hereinafter referred to as the second eccentric portion) 28b is housed in the second cylinder chamber 23.

[0045] An annular first roller 16 is fitted onto the outer peripheral surface of an eccentric portion 28a. When the rotating shaft 15 rotates, the first roller 16 rotates eccentrically within the first cylinder chamber 21, and a portion of the outer peripheral surface of the first roller 16 contacts the inner peripheral surface of the first cylinder chamber 21 in a sliding manner through an oil film.

[0046] The annular second roller 17 is fitted onto the outer peripheral surface of the eccentric portion 28b on the other side. When the rotating shaft 15 rotates, the second roller 17 rotates eccentrically within the second cylinder chamber 23, and a portion of the outer peripheral surface of the second roller 17 contacts the inner peripheral surface of the second cylinder chamber 23 in a sliding manner through an oil film.

[0047] like Figure 2 As shown, a blade 30 is disposed in the second cylinder 14. The blade 30 is supported in the second cylinder 14, for example, in a state where it is subjected to force in the radial direction by a force-applying unit. The leading end of the blade 30 presses against the outer peripheral surface of the second roller 17 in a slidable manner. The blade 30 cooperates with the second roller 17 to divide the second cylinder chamber 23 into an intake region and a compression region, and moves in the direction of protruding into the second cylinder chamber 23 or moving out of the second cylinder chamber 23 following the eccentric movement of the second roller 17. In this way, by the advance and retreat of the blade 30 relative to the second cylinder chamber 23, the volume of the intake region and the compression region of the second cylinder chamber 23 changes, and the gaseous refrigerant drawn into the second cylinder chamber 23 from the intake pipe 25b is compressed.

[0048] Although the illustration is omitted, the same blade 30 is also arranged in the first cylinder 13. Therefore, when the first roller 16 moves eccentrically in the first cylinder chamber 21, the volume of the suction region and the compression region of the first cylinder chamber 21 changes, and the gaseous refrigerant drawn into the first cylinder chamber 21 from the suction pipe 25a is compressed.

[0049] The high-temperature, high-pressure gaseous refrigerant compressed in the first cylinder chamber 21 and the second cylinder chamber 23 is discharged into the sealed container 10 via a discharge valve mechanism (not shown). The discharged gaseous refrigerant rises inside the sealed container 10. Furthermore, during the operation of the compression mechanism 11, the lubricating oil I stored in the oil reservoir 10c of the sealed container 10 is agitated. The agitated lubricating oil I becomes a mist and rises towards the discharge pipe 10b inside the sealed container 10 along with the flow of the gaseous refrigerant. An oil separator 100 is assembled in the sealed container 10 to separate the lubricating oil I contained in the rising gaseous refrigerant.

[0050] Figure 3 This is a diagram showing a portion of the structure of the electric motor 12 from above. (As shown...) Figure 2 and Figure 3 As shown, the electric motor 12 is a drive device for driving the compression mechanism 11, and is housed in the sealed container 10 between the compression mechanism 11 and the discharge pipe 10b. The electric motor 12 is a so-called internal rotor type electric motor, which has a rotor 33 mounted on the rotating shaft 15 and a stator 34 fixed to the inner circumferential surface of the peripheral wall 10a of the sealed container 10. By supplying power to the electric motor 12 from the power source, the rotor 33 rotates relative to the stator 34 about the central axis O1, causing the rotating shaft 15 to rotate together with the rotor 33. The rotating shaft 15 is supported by two bearings 20 and 22 to enable rotation.

[0051] The rotor 33 has a cylindrical iron core portion 35. The iron core portion 35 is, for example, constructed by stacking multiple annular electromagnetic steel plates along the axial direction. The stacked electromagnetic steel plates are integrated into a rotor 33, for example, by riveting. A through hole 36 is formed in the center of the iron core portion 35 for inserting an extension 27c of the rotating shaft 15. The extension 27c of the rotating shaft 15 is coaxially fixed to the center of the iron core portion 35 facing the through hole 36, for example, by pressing.

[0052] The upper part of the extension 27c of the rotating shaft 15 is formed with a diameter smaller than that of the insertion hole 36 of the iron core 35. The upper part of the extension 27c protrudes upward toward the iron core 35. A continuous circumferential gap is ensured between the outer peripheral surface of the upper part of the extension 27c and the inner peripheral surface of the center part of the iron core 35 facing the insertion hole 36.

[0053] Multiple plate-shaped permanent magnets 38 are integrally embedded inside the core portion 35. The permanent magnets 38 are arranged to surround the through hole 36. Furthermore, multiple first passages 39 are formed near the inner circumference of the core portion 35. The multiple first passages 39 respectively penetrate the core portion 35 axially and are arranged at predetermined intervals in the circumferential direction of the core portion 35 to surround the through hole 36. Through these first passages 39, the gaseous refrigerant discharged from the compression mechanism portion 11 into the interior of the sealed container 10 is guided to the discharge pipe 10b.

[0054] The rotor 33 includes a first balancing weight 40 and a second balancing weight 41. The first balancing weight 40 and the second balancing weight 41 are elements used to eliminate the rotational imbalance of the rotating shaft 15 that accompanies the eccentric movement of the first roller 16 and the second roller 17.

[0055] The first counterweight 40 consists of an annular first end plate 42 and a plurality of counterweight plates 43 stacked on the first end plate 42. The first end plate 42 is fixed to the upper end portion of the iron core 35. The second counterweight 41 consists of an annular second end plate 44 and a plurality of counterweight plates 45 stacked on the second end plate 44. The second end plate 44 is fixed to the lower end portion of the iron core 35.

[0056] The stator 34 has a stator core 34a and a coil 53. The stator core 34a consists of a generally cylindrical yoke 50 and a plurality of teeth (pole teeth) 51 protruding radially inward from the yoke 50. The coil 53 is wound around the teeth 51 of the stator core 34a.

[0057] The stator core 34a is formed into a generally cylindrical shape by stacking multiple generally fan-shaped electromagnetic steel plates axially and arranging them circumferentially, concentrically surrounding the rotor 33 along its approximately full axial length. The stacked electromagnetic steel plates are integrated, for example, by riveting, and adjacent fan-shaped electromagnetic steel plates in the circumferential direction are fixed to each other by welding. The stator core 34a is positioned and fixed to the peripheral wall 10a of the sealed container 10, for example, by thermoforming. Multiple teeth 51 are arranged at predetermined intervals in the circumferential direction (hereinafter referred to as the circumferential direction) of the yoke 50, protruding from the inner circumferential surface of the yoke 50 toward the outer circumferential surface of the rotor 33 along its full axial length. The axial direction of the yoke 50 is the direction in which its central axis (the same as the central axis O1) extends. A narrow air gap G is formed between the protruding end face 51c of the tooth 51 and the outer circumferential surface of the rotor 33. The number of teeth 51 can be arbitrarily set corresponding to the number of magnetic poles. exist Figure 3 In the example shown, nine teeth 51 are provided on the stator core 34a.

[0058] In addition, such as Figure 2As shown, the stator core 43a includes insulating components 55 and 56. The insulating components 55 and 56 are used to insulate the stator core 34a from its yoke 50 and the plurality of teeth 51, respectively, and from the coil (winding) 53. That is, the coil 53 is wound around the teeth 51 of the stator core 34a through the insulating components 55. The insulating components 55 are made of an insulator, such as a synthetic resin material with electrical insulating properties, such as polybutylene terephthalate resin, liquid crystal polymer resin, or polyphenylene sulfide resin. In the example shown, the insulating components 55 and 56 are arranged in pairs at both ends of the stator core 34a along its axial direction. One insulating component 55 is concentrically arranged with the stator core 34a at its upper end. The other insulating component 56 is concentrically arranged with the stator core 34a at its lower end.

[0059] like Figure 3 As shown, in this embodiment, the stator core 34a is constructed by assembling together multiple core components, i.e., segmented cores (hereinafter referred to as segmented cores) 34b, which are divided circumferentially. However, the stator core 34a may not have such a segmented structure. The stator core 34a may be divided, for example, according to each tooth 51 it has. In the example shown, the stator core 34a is divided into nine segmented cores 34b. These segmented cores 34b are arranged circumferentially to form a generally cylindrical stator core 34a as a whole. Two adjacent segmented cores 34b are arranged circumferentially such that their side surfaces 50e and 50f contact each other. Figure 3 The following is an example of a stator core 34a, which is generally cylindrical in shape, with three segmented cores 34b arranged circumferentially.

[0060] like Figure 3 As shown, multiple segmented cores 34b respectively constitute a portion of the yoke 50 in the stator core 34a and a tooth 51 protruding from a portion of the yoke 50. In other words, the stator core 34a is configured to be divided into multiple segmented cores 34b, each segmented core 34b including a tooth 51 and a portion of the yoke 50 protruding from the tooth 51.

[0061] The portion constituting part of the magnetic yoke 50 includes: an outer peripheral surface 50a forming the outer peripheral side of the stator core 34a; a flat inner peripheral surface 50b facing the slot 52; flat end surfaces 50c and 50d connecting to the outer peripheral surface 50a and the inner peripheral surface 50b at their respective axial ends; and flat side surfaces 50e and 50f contacting adjacent segmented cores 34b. The adjacent segmented cores 34b in the circumferential direction are arranged such that the side surface 50e of one segmented core 34b contacts the side surface 50f of the other segmented core 34b.

[0062] The portion constituting tooth 51 includes: a pair of side portions 51a, 51b extending radially toward rotor 33 from the inner circumferential portion 50b constituting yoke 50 in the segmented core 34b; a protruding end portion 51c connecting the inner diameter edges of these side portions 51a, 51b to each other; and flat end portions 51d, 51e connected to the side portions 51a, 51b and the protruding end portion 51c at both ends in the axial direction, respectively. The side portions 51a, 51b have a pair of protrusions 51f, 51f, which protrude circumferentially from the side portions 51a, 51b and connect to the protruding end portion 51c and the end portions 51d, 51e, and are continuous along the entire axial length of the segmented core 34b. The protruding end portion 51c is located at the front end of the inner diameter side of tooth 51 and is a portion facing away from the outer circumferential surface of the core portion 35 of rotor 33, separated by a narrow air gap G. End face 51d is coplanarly continuous with end face 50c of the yoke 50, and end face 51e is coplanarly continuous with end face 50d of the yoke 50. These end faces 50c, 50d and 51d, 51e constitute the segmented core 34b, specifically the end faces at both ends of the stator core 34a along its axial direction.

[0063] like Figure 3 As shown, slots 52 are formed on both sides of the stator core 34b in the circumferential direction between adjacent teeth 51 in the stator core 34a, or in other words, on both sides of the stator core 34b, separated by teeth 51. Slots 52 are spaces for accommodating coils 53 wound around teeth 51. Slots 52 are spaced apart in the circumferential direction of the yoke 50 and are continuous along the entire axial length of the yoke 50.

[0064] Furthermore, the yoke 50 has a plurality of second passages (hereinafter referred to as slots) 54. The plurality of slots 54 are axially extending recesses provided on the outer peripheral surface 50a of the yoke 50, and are arranged at predetermined intervals in the circumferential direction of the yoke 50. That is, the plurality of slots 54 are continuous in the axial direction and are formed by recessing the outer peripheral surface 50a of the yoke 50. The outer peripheral surface 50a of the yoke 50 is, for example, the fitting surface of the stator core 34a relative to the peripheral wall 10a of the sealed container 10 when hot-pressed, and is in close contact with the peripheral wall 10a. Thus, a plurality of axially communicating spaces are created between the yoke 50 and the peripheral wall 10a of the sealed container 10 at positions corresponding to the slots 54. Therefore, through these plurality of spaces, i.e., the slots 54, the gaseous refrigerant discharged from the compression mechanism section 11 into the interior of the sealed container 10 is guided to the discharge pipe 10b via the slots 54.

[0065] Furthermore, in this embodiment, the yoke 50 is axially continuous and has a plurality of holes 60 extending through it. The holes 60 are axially continuous, extending the yoke 50 from end face 50c to end face 50d. Thus, in the yoke 50, a plurality of axially connected spaces are created at positions corresponding to the holes 60 from the end face 50d side to the end face 50c side of the yoke 50. Therefore, through these multiple spaces, i.e., the holes 60, the gaseous refrigerant discharged from the compression mechanism section 11 into the interior of the sealed container 10 is guided to the discharge pipe 10b via the holes 60.

[0066] As described above, in this embodiment, the stator core 34a is divided into a plurality of (for example, nine) segmented cores 34b. The slot portion 54 and the hole portion 60 are equally disposed in each of these segmented cores 34b. Figure 4 It is a schematic representation of the structure of the segmented core 34b, and a vertical sectional view of the segmented core 34b relative to the axial direction.

[0067] like Figure 3 and Figure 4 As shown, each of the multiple segmented iron cores 34b has one slot 54 and two holes 60. Figure 4 In the axial vertical section of the segmented iron core 34b shown, the slot 54 is arranged along the centerline of the tooth 51 of the segmented iron core 34b. Figure 4 The single-dot dashed line shown is on L51. The center line L51 of tooth 51 is an imaginary line that roughly bisects tooth 51 in the circumferential direction. That is, multiple teeth 51 are formed in a shape that is approximately linearly symmetrical with respect to the center line L51.

[0068] exist Figure 4 In the axial vertical section of the segmented iron core 34b shown, the inner peripheral surface 50b of the yoke 50 is approximately perpendicularly continuous with respect to the center line L51 of the tooth 51. In the example shown, the side surfaces 51a and 51b of the tooth 51 are approximately parallel to the center line L51 of the tooth 51, and these side surfaces 51a and 51b are approximately perpendicularly connected to the inner peripheral surface 50b of the yoke 50.

[0069] like Figure 3 and Figure 4 As shown, the plurality of grooves 54 each have a groove bottom 54a that is flat and continuous in the axial direction, and a pair of groove wall portions 54b, 54c that rise obliquely from the edge of the groove bottom 54a and are connected to the outer peripheral surface 50a of the magnetic yoke 50. Figure 4In the axial vertical section of the segmented iron core 34b shown, the groove bottom 54a and the center line L51 of the tooth 51 are approximately perpendicularly continuous, and the groove wall portions 54b and 54c are flat, inclined surfaces connecting the groove bottom 54a and the outer peripheral surface 50a. In the example shown, the groove portion 54 has a generally trapezoidal shape (bathtub shape) outline defined by the groove bottom 54a and the groove wall portions 54b and 54c, but its outline is not limited to this. The outline of the groove portion may also be, for example, a generally rectangular shape, a generally V-shaped shape, a keyed stepped shape, etc.

[0070] exist Figure 4 In the axial vertical cross-section of the segmented iron core 34b shown, the groove 54 is formed in a linearly symmetrical shape with respect to the center line L51. In other words, the groove bottom 54a is formed in a linearly symmetrical shape with respect to the center line L51, and the groove wall portions 54b and 54c are arranged in pairs on both sides of the center line L51 in a linearly symmetrical manner with respect to the center line L51.

[0071] like Figure 3 and Figure 4 As shown, each of the plurality of holes 60 has a triangular opening, having three facets (first facet 60a, second facet 60b, and third facet 60c) surrounding the opening. However, the shape of the opening of the hole 60 is not limited to this triangular shape and can be arbitrary. Figure 4 In the axial vertical cross-section of the segmented core 34b shown, the first facet 60a is a flat facet that is substantially parallel to the inner peripheral facet 50b of the yoke 50 and the bottom 54a of the slot 54; the second facet 60b is a flat facet that is substantially parallel to the outer peripheral facet 50a of the yoke 50; and the third facet 60c is a flat facet that is substantially parallel to the slot wall portion 54b (or slot wall portion 54c) of the slot 54. In other words, the first facet 60a is substantially perpendicular and continuous with respect to the center line L51 of the tooth 51 and the side portions 51a and 51b, respectively.

[0072] like Figure 4 As shown, there are partition walls 57b and 57c separating the hole 60 from the outer peripheral surface 50a of the yoke 50, located between the opening edge of the hole 60 and the outer peripheral surface 50a. In the example shown, partition wall 57b separates the second surface 60b of the hole 60 from the outer peripheral surface 50a of the yoke 50, and partition wall 57c separates the third surface 60c of the hole 60 from the groove walls 54b and 54c of the groove 54 of the yoke 50. Partition walls 57b and 57c are connected at positions corresponding to the connection positions of the second surface 60b and the third surface 60c of the hole 60.

[0073] exist Figure 4In the axial vertical section of the segmented core 34b shown, the holes 60 are arranged in pairs on both sides of the center line L51 in a linearly symmetrical manner with respect to the center line L51. That is, in the segmented core 34b, two holes 60 (61, 62) of the same shape are arranged one at each position in a linearly symmetrical manner with respect to the center line L51. These holes 61 and 62 are arranged as follows.

[0074] exist Figure 4 In the axial vertical section of the segmented iron core 34b shown, the holes 61 and 62 are respectively positioned at a distance D41 greater than or equal to the distance D42. The distance D41 is the shortest distance between the opening edges of the holes 61 and 62 in the segmented iron core 34b and the inner circumferential surface 50b of the magnetic yoke 50 in the segmented iron core 34b. Figure 4 (D41 is the distance shown in the figure). In the example, distance D41 is the shortest distance between the first face 60a and the inner circumferential face 50b of the holes 61 and 62. Distance D42 is the shortest distance between the bottom 54a of the slot 54 in the segmented iron core 34b and the inner circumferential face 50b of the yoke 50 in the segmented iron core 34b. Figure 4 (Distance shown in D42).

[0075] That is, in Figure 4 In the axial vertical section of the segmented core 34b shown, the opening edges of the holes 61 and 62 and the bottom 54a of the slot 54 are located on the same vertical line relative to the center line L51 of the tooth 51, or the opening edges of the holes 61 and 62 are located at a position closer to the outer peripheral surface 50a of the yoke 50 than this vertical line. In the example shown, the first surface 60a of the holes 61 and 62 and the bottom 54a of the slot 54 are located on approximately the same vertical line relative to the center line L51 of the tooth 51.

[0076] In addition, in such Figure 4 In the axial vertical cross-section of the segmented iron core 34b shown, the holes 61 and 62 are respectively positioned at a distance D43 shorter than the distance D44. The distance D43 is the shortest distance between the opening edges of the holes 61 and 62 in the segmented iron core 34b and the groove walls 54b and 54c of the grooves 54 in the segmented iron core 34b. Figure 4 (D43 is the distance shown in the figure). In the example, distance D43 is the shortest distance between the third face 60c of the holes 61 and 62 and the groove walls 54b and 54c. Distance D44 is the shortest distance between the opening edge of the holes 61 and 62 of the segmented core 34b and the side faces 50e and 50f of the yoke 50 in the segmented core 34b. Figure 4 (Distance shown in the figure D44). In the example drawing, distance D44 is the shortest distance between the connection point of the first face 60a and the second face 60b of the holes 61 and 62 and the side faces 50e and 50f. That is, in Figure 4 In the axial vertical section of the segmented iron core 34b shown, the opening edges of the holes 61 and 62 are located near the groove wall portions 54b and 54c (in other words, the partition wall portion 57c) of the groove portion 54 in the segmented iron core 34b, rather than the side portions 50e and 50f of the magnetic yoke 50 in the segmented iron core 34b.

[0077] Here, the angle formed by the first surface 60a and the second surface 60b is an acute angle. Furthermore, the angle formed by the second surface 60b and the third surface 60c is an obtuse angle.

[0078] Thus, the hole 60 is shaped as a flat shape that is longer in the circumferential direction.

[0079] Thus, according to this embodiment, the stator 34 of the electric motor 12 has a plurality of slots 54 and a plurality of holes 60 in the yoke 50. That is, for example in the compressor 2, the gaseous refrigerant discharged from the compression mechanism 11 into the interior of the sealed container 10 can be guided to the discharge pipe 10b through these slots 54 and holes 60 via multiple paths.

[0080] That is, by providing a hole 60 in addition to the slot 54 in the magnetic yoke 50, the path for guiding the refrigerant can be extended by an amount equivalent to that of the hole 60. Therefore, compared to the case where only the slot 54 is provided, the cooling efficiency of the motor 12 can be improved, resulting in higher output. In other words, the cooling efficiency of the motor 12 can be improved without expanding the slot 54.

[0081] As described above, the slot 54 is an axially extending recess provided on the outer peripheral surface 50a of the yoke 50, which, for example, is the fitting surface of the stator core 34a relative to the peripheral wall 10a when it is hot-pressed onto the sealed container 10. Therefore, expanding the slot 54 on the outer peripheral surface 50a reduces the fitting surface relative to the peripheral wall 10a of the sealed container 10. Therefore, according to this embodiment, the cooling efficiency of the motor 12 can be improved without reducing the fitting surface relative to the peripheral wall 10a due to expanding the slot 54. That is, the cooling efficiency of the motor 12 can be improved without reducing the holding force of the stator core 34a relative to the sealed container 10 when it is hot-pressed onto the sealed container 10.

[0082] Furthermore, the yoke 50 has a hole 60, which absorbs the stress (hot-pressing stress) generated in the stator core 34a when it is hot-pressed into the sealed container 10, thus mitigating the stress. This reduces energy loss (iron loss) in the stator core 34a. Additionally, the hole 60 suppresses deformation of the stator core 34a and contributes to the attenuation of deformation, thereby reducing noise during motor 12 operation.

[0083] In addition, in such Figure 4 In the axial vertical section of the segmented iron core 34b shown, the holes 60 are respectively positioned at a distance from D41 greater than or equal to D42, and at a distance from D43 shorter than or equal to D44. That is, in this vertical section, the opening edge of the hole 60 and the bottom 54a of the groove 54 are on the same vertical line relative to the center line L51 of the teeth 51 in the segmented iron core 34b, or the opening edge of the hole 60 is located closer to the outer peripheral surface 50a of the yoke 50 in the segmented iron core 34b than this vertical line. Furthermore, in this vertical section, the opening edge of the hole 60 is located near the groove wall portions 54b and 54c of the groove 54 in the segmented iron core 34b than the side portions 50e and 50f of the yoke 50 in the segmented iron core 34b.

[0084] Therefore, the holes 60 can be easily avoided from the magnetic flux path generated by the conduction through the coil 53, and these holes 60 can be suppressed from becoming magnetic reluctance on that magnetic flux path. Thus, it is possible to prevent the increase in magnetic reluctance caused by the holes 60.

[0085] Here, the yoke 50 has a hole 60, and thus, compared with a comparative example without this hole 60, the induced voltage and torque in the motor 12 are reduced, while torque fluctuations and iron losses are increased. On the other hand, in Figure 4 In the axial vertical section of the segmented iron core 34b shown, the holes 60 are respectively arranged at a distance from D41 that is greater than or equal to the distance from D42, and respectively arranged at a distance from D43 that is shorter than the distance from D44. As a result, compared with the above comparative example, the decrease in induced voltage and torque in the motor 12 can be suppressed to a great extent, and the increase in torque fluctuation and iron loss can be suppressed to a great extent. Moreover, the cooling efficiency of the motor 12 can be improved compared with the above comparative example.

[0086] The refrigerant used in the compressor 2 of this embodiment is, for example, a low-pressure refrigerant such as R290, R454B, or R454C. In a refrigeration cycle using these refrigerants, compared to the case where refrigerants such as R32 or R410A are used, the difference in cooling capacity due to the same pressure loss is greater, and the cooling capacity may decrease. Therefore, in the case of using low-pressure refrigerants such as R290, R454B, or R454C, in order to suppress the decrease in cooling capacity and maintain the same cooling capacity, the compression volume in the compressor 2 needs to be larger than when using refrigerants such as R32 or R410A. However, when the compression volume of the compressor 2 is increased, the refrigerant flow rate increases accordingly, which tends to worsen the pressure loss.

[0087] As described above, according to this embodiment, by providing a hole 60 in addition to the slot 54 in the magnetic yoke 50, the path for guiding the refrigerant can be extended by an amount equivalent to that of the hole 60. Therefore, even when using low-pressure refrigerants such as R290, R454B, and R454C as the refrigerant for the compressor 2, the deterioration of pressure loss can be suppressed, and the cooling capacity can be maintained at the same level as when using refrigerants such as R32 and R410A.

[0088] Furthermore, by making the orifice 60 flat, the surface area of ​​the orifice 60 can be increased even in a small space, thereby improving the cooling capacity of the refrigerant. In particular, by making the angle of the circumferential side of the yoke 50 acute and the angle of the radial outer circumference obtuse, the required refrigerant path and surface area can be ensured even in a small space, and it can be configured to suppress torque fluctuations and the increase of iron losses.

[0089] (Second Implementation) like Figure 4 As shown, in the segmented core 34b of the stator core 34a in the first embodiment, the slot portion 54 is formed in a linearly symmetrical shape with respect to the center line L51. That is, the slot bottom 54a is formed in a linearly symmetrical shape with respect to the center line L51, and the slot wall portions 54b and 54c are arranged in pairs on both sides with respect to the center line L51 in a linearly symmetrical manner. In addition, one hole portion 60 is arranged on each side with respect to the center line L51 in a linearly symmetrical manner with respect to the center line L51.

[0090] However, in Figure 4 In the axial vertical cross-section of the segmented iron core 34b shown, the slot 54 and the hole 60 are not limited to the manner illustrated in the figure. Hereinafter, they will be discussed in conjunction with... Figure 4 An example of a groove and hole with different configurations will be described as a second embodiment. Figure 5 This is a schematic diagram of the structure of the segmented core 34b in the second embodiment, shown as a vertical cross-sectional view of the segmented core 34b relative to the axial direction. In the second embodiment, the structure other than the slot 70 is similar to... Figures 1 to 4 The first embodiment shown is the same. Therefore, for Figure 5 The structure other than the groove 70 in the second embodiment shown is appropriately referenced. Figures 1 to 4 The explanation is omitted.

[0091] like Figure 5 As shown, in this embodiment, the groove 70 is extended to be consistent with... Figure 4 The groove 54 shown in the first embodiment has a different shape (hereinafter referred to as the first groove shape) than the groove 70. That is, the second groove shape is more extensive than the first groove shape.

[0092] The groove 70 is formed as Figure 4 The first embodiment shown depicts a configuration where the groove 54 and the hole 61 are continuously connected. (As shown...) Figure 5 As shown, in this embodiment, the slot 70 is formed in a vertical section along the axial direction of the segmented core 34b, arranged in pairs on both sides with respect to the center line L51. Figure 4 The area corresponding to one of the holes 61 and 62 shown is continuously connected to the groove 54.

[0093] That is, in Figure 5 In the embodiment shown, there is no [missing information]. Figure 4 The third face 60c of the hole 61 shown is separated from the groove wall 54b of the groove 54 by a partition wall 57c, which has only a portion (hereinafter referred to as the partition wall portion) 58b corresponding to the partition wall portion 57b that separates the second face 60b of the hole 61 from the outer peripheral face 50a. The inner peripheral face (the face opposite to the outer peripheral face 50a) 70b of the partition wall portion 58b... Figure 4 The second face 60b of the hole 61 shown is substantially the same. Additionally, Figure 5 The groove bottom 70a of the groove 70 shown is... Figure 4 The bottom 54a of the groove portion 54 shown is coplanar with the portion of the hole portion 61 corresponding to the first face portion 60a, and the face portion 70b is coplanar with the portion of the hole portion 61 corresponding to the first face portion 60a. The face portion 70b on the inner circumferential side of the partition wall corresponding portion 58b corresponds to the groove wall portion 54c on the opposite side of the groove wall portion 54c that is continuous with the bottom 70a of the groove portion 70.

[0094] In contrast, Figure 5 In the embodiment shown, Figure 4 The hole 62 shown, the partition wall 57b that separates the second surface 60b of the hole 62 from the outer peripheral surface 50a, and the partition wall 57c that separates the third surface 60c of the hole 62 from the groove wall 54b of the groove 54 are all provided.

[0095] Thus, the groove 70 corresponds to the shape in the first embodiment after removing the partition wall 57c between the groove 54 and the hole 61. Therefore, compared with the groove 54 in the first embodiment, the groove 70 expands the area corresponding to the hole 61 and the partition wall 57c. Figure 4 The shortest distance between the opening edge of the hole 61 of the segmented iron core 34b and the side surface 50e of the magnetic yoke 50 in the segmented iron core 34b. Figure 4 The distance shown in D44 is equivalent to Figure 5The distance D54 shown is the shortest distance between the edge of the slot 70 of the segmented iron core 34b and the side surface 50e of the yoke 50 in the segmented iron core 34b. In the example shown, distance D54 is the shortest distance between the connection point of the slot bottom 70a of the slot 70 and the inner circumferential surface 70b of the corresponding portion 58b of the partition wall, and the side surface 50e, which is the same as distance D44.

[0096] Furthermore, unlike the example shown in the figure, the second groove form, which is the groove portion 70, can also extend to an area corresponding to the hole portion 62 and the partition wall portion 57c between the hole portion 62 and the groove portion 54 in the first embodiment. When set as... Figure 4 In the case where the partition wall 57c between one of the holes 61 and 62 and the slot 54 is removed, the second slot can be configured, for example, to be a configuration in which the hole 60 located on the leading side (front side) of the hole 60 in the rotation direction of the rotating shaft of the motor 12 and the rotor 33, which are arranged in pairs, is continuously connected in region. With this configuration, in Figure 5 In the example shown, the rotation direction is clockwise. In this case, the hole 62 located on the rear side (rear side) in this rotation direction can be left as a through hole for the magnetic yoke 50.

[0097] Alternatively, the second groove shape can also be Figure 4 The shape shown is the result after all the partition walls 57c between the holes 61 and 62 and the groove 54 have been removed. In this case, the portions corresponding to the two partition walls 57b are left.

[0098] Even in the second slot configuration, there is a partition wall portion 57b and a corresponding partition wall portion 58b. The partition wall portion 57b and the corresponding partition wall portion 58b include, for example, the outer peripheral portion 50a of the yoke 50, which is the fitting surface relative to the peripheral wall 10a when the stator core 34a is hot-pressed onto the sealed container 10. Therefore, according to this embodiment, the fitting surface relative to the peripheral wall 10a can be maintained without reducing the amount of fitting surface. Thus, similarly to the first embodiment, the cooling efficiency of the motor 12 can be improved while maintaining the holding force of the stator core 34a relative to the sealed container 10 when it is hot-pressed onto the sealed container 10, without reducing the strength of the stator core 34a relative to the sealed container 10.

[0099] The above description illustrates several embodiments of this utility model, but these embodiments are merely illustrative and not intended to limit the scope of the utility model. These new embodiments can be implemented in various other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the utility model. These embodiments and their variations are included within the scope and spirit of the utility model, and are encompassed by the scope of the utility model as described in the claims and its equivalents.

Claims

1. A stator of an electric motor, characterized by have: A cylindrical stator core surrounds a rotor fixed to and causing the rotating shaft to rotate; and The winding is wound around the stator core. The stator core includes: a cylindrical yoke concentrically surrounding the rotor; a plurality of teeth projecting radially inward from the yoke and spaced apart circumferentially from the yoke; and a plurality of slots formed between adjacent teeth in the circumferential direction and housing the windings. The magnetic yoke has: a groove, continuous in the axial direction along the axis of rotation, such that the outer peripheral surface of the yoke is recessed to allow refrigerant to pass through; and a hole, continuous in the axial direction, penetrating the magnetic yoke. In the vertical section of the stator core relative to the axial direction, the slot is positioned on an imaginary line that roughly bisects the tooth in the circumferential direction, and the hole is positioned at a position where the shortest distance between the opening edge of the hole and the inner circumferential surface of the yoke is greater than the shortest distance between the slot and the inner circumferential surface of the yoke.

2. The stator of the electric motor according to claim 1, characterized in that, The stator core is composed of multiple segmented cores, each segmented core including one tooth and a portion of the yoke protruding from the tooth. Each of the plurality of said segmented iron cores has a contact surface that contacts other said segmented iron cores adjacent in the circumferential direction. In the vertical cross-section, the shortest distance between the opening edge of the hole in the segmented iron core and the groove in the segmented iron core is shorter than the shortest distance between the opening edge of the hole and the contact surface of the segmented iron core.

3. The stator of the electric motor according to claim 1, characterized in that, In the vertical cross-section, the groove is formed in a linearly symmetrical shape with respect to the imaginary line, and the holes are arranged in pairs on both sides of the imaginary line in a linearly symmetrical manner with respect to the imaginary line.

4. The stator of the electric motor according to claim 3, characterized in that, In the vertical section, the groove extends into a second groove shape, which is different from the first groove shape that is linearly symmetrical with respect to the imaginary line. The second groove shape is formed to be continuously connected to a region corresponding to one of the paired holes.

5. The stator of the electric motor according to claim 4, characterized in that, In the vertical cross-section, the second groove is formed in a shape that is continuously connected to the region corresponding to the leading side of the hole in the rotation direction of the rotation axis among the paired holes.

6. The stator of the electric motor according to claim 1, characterized in that, The groove has a continuous groove bottom in the axial direction. In the vertical section, the inner circumferential surface of the magnetic yoke and the bottom of the groove are respectively perpendicular to the imaginary line.

7. An electric motor, characterized in that, have: The stator according to any one of claims 1 to 6; and The rotor.

8. A compressor, characterized in that, have: A cylindrical, sealed container; A compression mechanism compresses the refrigerant inside the sealed container and discharges the compressed refrigerant into the interior of the sealed container; and The electric motor of claim 7 is housed in the sealed container and drives the compression mechanism.

9. The compressor according to claim 8, characterized in that, The refrigerant is any one of R290, R454B, and R454C.

10. A refrigeration cycle device, characterized in that, have: A circulation loop for circulating the refrigerant, and connected to a condenser, an expansion device, and an evaporator; and The compressor of claim 8 is connected to the circulation loop between the condenser and the evaporator.

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