Electric motor and compressor

Abstract

Provided is an electric motor and compressor, which discloses a technique for reducing current flowing in a closed circuit formed by first to third phase windings connected in a delta configuration. A main body portion of a first electric insulator assembly (second electric insulator assembly) disposed on an axial first side (axial second side) of a stator core has a plurality of first grooves and second grooves in connection portions that connect a top surface of the main body portion to side surfaces of the main body portion. First to third phase windings connected in a delta configuration have a plurality of winding portions wound around teeth and at least one overlap portion connecting two winding portions of the plurality of winding portions. The overlap portions of each phase are disposed along an outer peripheral surface of the outer wall portion in a manner such that a length along a circumferential direction is substantially equal.

Description

Technical Field

[0001] This disclosure relates to an electric motor disposed in a compressor, and in particular, to an electric motor in which the stator windings are delta connected. Background Technology

[0002] Air conditioners (for residential, automotive, and commercial use, etc.) have compressors. Furthermore, the compressor includes a compression mechanism and an electric motor that drives the compression mechanism.

[0003] As a motor driving the compression mechanism, for example, a motor comprising a stator having stator windings and a rotor having multiple permanent magnets is used. Furthermore, as a winding method for winding the stator windings, a concentrated winding method in which the stator windings are directly wound onto the teeth is known. By using a concentrated winding method, the length in the axial direction can be shortened compared to using a distributed winding method.

[0004] Alternatively, a motor with stator windings including the first to third phase windings connected in a delta configuration is used. By delta-connecting the first to third phase windings, a neutral point is not required in the case of a star connection, thus eliminating the need for neutral point-related operations.

[0005] On the other hand, when the first to third phase windings are delta connected, the circulating current flows in the closed circuit formed by the first to third phase windings.

[0006] When circulating current flows in a closed circuit formed by the first to third phase windings connected in a delta configuration, heat is generated due to copper losses.

[0007] Previously, for example, Japanese Patent Application Publication No. 2008-301670 disclosed an electric motor control device that controls the voltage applied to the first to third phase windings to counteract the circulating current in order to reduce the influence of the circulating current flowing in the closed circuit formed by the first to third phase windings connected in a delta configuration.

[0008] Existing technical documents

[0009] Japanese Patent Application Publication No. 2008-301670 Summary of the Invention

[0010] The problem the invention aims to solve

[0011] By delta-connecting the first to third phase windings, the output can be improved compared to a star connection, and furthermore, neutral point-related operations are eliminated. Therefore, it is desirable to use a motor with delta-connected first to third phase windings as the motor driving the compression mechanism.

[0012] However, when the first to third phase windings are delta-connected, heat is generated due to the circulating current flowing in the closed circuit formed by the first to third phase windings. When using a motor with a rotor containing multiple permanent magnets (a permanent magnet motor), the permanent magnets demagnetize due to the heat generated by the circulating current. When the permanent magnets are irreversibly demagnetized due to the heat generated by the circulating current (a state where the magnetic properties do not recover even if the temperature recovers), the characteristics of the motor deteriorate. To prevent irreversible demagnetization of the permanent magnets due to the heat generated by the circulating current, it is necessary to use permanent magnets with high coercivity, such as neodymium magnets with a high content of at least one of terbium (Tb) and dysprosium (Dy). Such permanent magnets with high coercivity are relatively expensive.

[0013] Here, the technology disclosed in Japanese Patent Application Publication No. 2008-301670 is considered. However, the technology disclosed in Japanese Patent Application Publication No. 2008-301670 is a technology for controlling the voltage applied to the first to third phase windings to counteract the circulating current, which requires a complex control device.

[0014] The purpose of this disclosure is to disclose a technique for reducing the circulating current flowing in a closed circuit formed by the delta-connected first to third phase windings without using complex control devices.

[0015] Solution for solving the problem

[0016] The first disclosure relates to an electric motor housed together with a compression mechanism within a sealed container.

[0017] The first disclosed electric motor includes a rotor and a stator.

[0018] The rotor includes a rotor core with multiple permanent magnets, and the rotor is supported so that it can rotate relative to the stator.

[0019] The stator includes a stator core, a first electrical insulator assembly and a second electrical insulator assembly, and stator windings.

[0020] The stator core is formed as a cylindrical shape extending along the axial direction. In addition, the stator core has: a magnetic yoke that extends circumferentially; and a plurality of teeth that are arranged separately in the circumferential direction and extend radially inward from the magnetic yoke.

[0021] The first and second electrical insulator assemblies each have an outer wall portion, multiple inner wall portions, and multiple main branches. The outer wall portions extend circumferentially. The multiple inner wall portions are circumferentially separated and arranged at radially inward positions compared to the outer wall portions, and extend circumferentially. The multiple main branches are disposed between each inner wall portion and the outer wall portion, and extend radially.

[0022] The first electrical insulator assembly and the second electrical insulator assembly are respectively disposed on the first side and the second side of the stator core in the axial direction.

[0023] The outer wall portion of at least one of the first electrical insulator assembly and the second electrical insulator assembly has a plurality of notches and a plurality of grooves.

[0024] Multiple notches are arranged separately in the circumferential direction. Each notch opens on the side opposite to the stator core along the axial direction, and also opens on the inner circumferential surface of the outer wall portion and the outer circumferential surface of the outer wall portion.

[0025] Multiple grooves are separately arranged on the outer peripheral surface of the outer wall in the axial direction. Each groove extends circumferentially, opens radially outward, and is also open in one of the multiple notches and another notch.

[0026] The stator windings include phase 1 to phase 3 windings connected in a delta configuration. Each phase winding has multiple winding portions and at least one overlap portion.

[0027] With the outer wall portion of the first electrical insulator assembly and the second electrical insulator assembly respectively arranged on the first side of the axial direction and the second side of the axial direction of the stator core in a manner that the outer wall portion and the multiple main stems are respectively opposite to the magnetic yoke and the multiple teeth, each winding portion is wound around the teeth.

[0028] At least one overlap extends outward from one of the multiple winding portions through one of the multiple notches in the outer wall portion of at least one electrical insulator assembly, is arranged circumferentially through at least one of the multiple slots in the outer wall portion, and extends inward from the outer wall portion through another of the multiple notches in the outer wall portion.

[0029] Each tooth base has: a first tooth base side surface disposed on a circumferential first side and extending parallel to the tooth centerline; and a second tooth base side surface disposed on a circumferential second side and extending parallel to the tooth centerline.

[0030] In the electric motor disclosed herein, each of the first to third phase windings has multiple winding portions and at least one overlapping portion formed by a continuous single wire.

[0031] In addition, each winding portion of the first to third phase windings begins to wind radially outward around the tooth base and ends radially outward.

[0032] Furthermore, each main stem of the first and second electrical insulator assemblies has a first main stem side surface, a second main stem side surface, and a main stem top surface. The first main stem side surface is disposed on the first circumferential side of the main stem and extends parallel to the tooth centerline of the tooth opposite to the main stem. The second main stem side surface is disposed on the second circumferential side of the main stem and extends parallel to the tooth centerline of the tooth opposite to the main stem. The main stem top surface is disposed on the side opposite to the stator core along the axial direction. Moreover, the connection portion of each main stem where the first main stem side surface connects to the main stem top surface has a plurality of first guide grooves formed radially separately, and the connection portion where the second main stem side surface connects to the main stem top surface has a plurality of second guide grooves formed radially separately. The first guide grooves and second guide grooves extend circumferentially.

[0033] In addition, the circumferential lengths of the overlap portions of the first to third phase windings are configured to be approximately equal, and the resistance difference between the first and third phase windings is configured to be within ±3%.

[0034] In the first disclosed electric motor, the circulating current flowing in the closed circuit formed by the first to third phase windings connected in a delta configuration can be reduced without using a complex control device. Furthermore, this suppresses the temperature rise caused by the circulating current flowing in the closed circuit, eliminating the need for expensive permanent magnets with high coercivity.

[0035] In different configurations of the electric motor disclosed in the first article, the multiple gaps are configured such that the circumferential length of the portion of each overlapping portion of the first phase winding to the third phase winding located between one of the multiple gaps and another of the multiple gaps is approximately equal.

[0036] In this method, by having each overlapping portion pass through one of the multiple notches, at least one of the multiple slots, and another of the multiple notches, it is easy to make the circumferential lengths of each overlapping portion approximately equal.

[0037] In the different types of electric motors disclosed in the first article, permanent magnets with a coercivity in the range of 18,000 (Oe) to 26,500 (Oe) are used as permanent magnets.

[0038] In motors with star connections of the first to third phase windings, permanent magnets with coercivity ranging from 18,000 (Oe) to 26,500 (Oe) are used.

[0039] In this method, the same permanent magnet used in the case of star connection of the first phase winding to the third phase winding can be used to perform delta connection of the first phase winding to the third phase winding while preventing irreversible demagnetization of the permanent magnet due to temperature rise caused by circulating current.

[0040] In the different embodiments of the electric motor disclosed in the first disclosure, the temperature rise of the permanent magnet is suppressed to within 8°C when the ambient temperature of the electric motor is lower than 150°C.

[0041] When the air conditioner operates below 150°C, the motor needs to withstand heat at 150°C. The permanent magnets used in a motor with a star connection between the first and third phase windings are irreversibly demagnetized when the ambient temperature rises by 8°C at 150°C.

[0042] In this method, the same permanent magnet used in the case of star connection of the first phase winding to the third phase winding can be used to perform delta connection of the first phase winding to the third phase winding while preventing irreversible demagnetization of the permanent magnet due to temperature rise caused by circulating current.

[0043] In the different embodiments of the electric motor disclosed in the first disclosure, the wire forming the winding portion and the overlapping portion is formed by a conductor and an insulating covering portion disposed around the conductor.

[0044] In this method, the diameter of the conductor is within the range of ±0.002mm to ±0.03mm relative to the conductor diameter setting value.

[0045] This reduces the circulating current caused by the deviation in the resistance values ​​of each phase winding.

[0046] In addition, the diameter of the wire is within the range of ±0.018mm to ±0.17mm relative to the wire diameter setting value.

[0047] When the diameter of the wire deviates, the resistance value also deviates. Furthermore, when the wire diameter deviates, the circumference of the winding portion formed by the teeth on the wire deviates, thus also causing a deviation in the resistance value.

[0048] Furthermore, by reducing the deviation in the thickness of the insulating film surrounding the conductor, the deviation in the wire diameter can also be reduced.

[0049] Therefore, while guiding the wire using multiple first guide slots and second guide slots formed on the main body of the first and second electrical insulator assemblies, the winding portions can be arranged and wound, and the difference in resistance value of each phase winding can be kept within ±3%.

[0050] In different embodiments of the electric motor disclosed in the first disclosure, the outer peripheral surface of the outer wall portion of at least one electrical insulator assembly extends parallel to the axial direction.

[0051] In addition, there are multiple slots, including slots in groups 1 to 3. Slots in group 1 are located on the side opposite to the stator core. Slots in group 3 are located on the stator core side closer to the stator core than slots in group 1. Slots in group 2 are located between slots in group 1 and slots in group 3.

[0052] Furthermore, the depth of the second set of grooves is configured to be greater than the depth of the third set of grooves and less than the depth of the first set of grooves (the depth of the third set of grooves < the depth of the second set of grooves < the depth of the first set of grooves).

[0053] In this method, the resistance deviation of the first phase winding to the third phase winding can be further reduced.

[0054] In different embodiments of the electric motor disclosed in the first disclosure, the outer peripheral surface of the outer wall portion of at least one electrical insulator assembly extends obliquely relative to the axial direction, with its end on the side opposite to the stator core positioned radially inward than the end on the stator core side.

[0055] In addition, similar to the above method, the multiple slots include a first group of slots to a third group of slots arranged separately along the axial direction.

[0056] Furthermore, the depths of the first to third groups of grooves are equal.

[0057] In this method, the resistance deviation of the first phase winding to the third phase winding can be further reduced.

[0058] In different embodiments of the electric motor disclosed in the first disclosure, the outer peripheral surface of the outer wall portion of at least one electrical insulator assembly extends parallel (including "generally parallel") to the axial direction.

[0059] Similarly, as described above, the plurality of grooves includes a first group of grooves to a third group of grooves arranged separately along the axial direction. Furthermore, at least one first protrusion is formed on the bottom surface of the second group of grooves. Additionally, at least one second protrusion is formed on the bottom surface of the third group of grooves.

[0060] Furthermore, the minimum gap between the first protrusion and the outer peripheral surface of the outer wall portion is configured to be larger than the minimum gap between the second protrusion and the outer peripheral surface of the outer wall portion and smaller than the depth of the first set of grooves ([minimum gap between the second protrusion and the outer peripheral surface of the outer wall portion < minimum gap between the first protrusion and the outer peripheral surface of the outer wall portion < depth of the first set of grooves]).

[0061] In this method, the resistance deviation of the first phase winding to the third phase winding can be further reduced.

[0062] The second disclosure relates to a compressor.

[0063] The compressor disclosed in the second disclosure includes: a compression mechanism; an electric motor that drives the compression mechanism; and a sealed container that houses the compression mechanism and the electric motor.

[0064] Furthermore, any of the aforementioned electric motors may be used as the electric motor.

[0065] The compressor disclosed in the second disclosure has the same effect as the electric motor described above.

[0066] The effects of the invention

[0067] By using the electric motor disclosed in the first disclosure and the compressor disclosed in the second disclosure, the current flowing in the closed circuit formed by the first phase winding to the third phase winding connected in a delta configuration can be reduced without using a complex control device. Attached Figure Description

[0068] Figure 1 This is a cross-sectional view of a compressor according to one embodiment.

[0069] Figure 2 Observing from the direction of arrow II-II Figure 1 A sectional view at that time.

[0070] Figure 3 Is Figure 1 The diagram shows the first electrical insulator assembly viewed from the direction of arrow III.

[0071] Figure 4 This is a three-dimensional view of the first electrical insulator assembly.

[0072] Figure 5 This is a diagram showing the connection status of the first to third phase windings.

[0073] Figure 6 yes Figure 3 A magnified view of a portion of the image.

[0074] Figure 7 This is a cross-sectional view of a tooth.

[0075] Figure 8 This is a diagram showing an example of a groove provided on the outer wall.

[0076] Figure 9 This is a diagram showing another example of a groove provided on the outer wall.

[0077] Figure 10 This is a diagram showing another example of a groove provided on the outer wall.

[0078] Figure 11 This diagram shows an example of a protrusion formed in a groove provided on the outer wall.

[0079] Figure 12 This is a diagram showing another example of a protrusion formed in a groove provided on the outer wall.

[0080] Explanation of reference numerals in the attached figures

[0081] 10. Compressor; 100. Sealed container; 111. Side wall; 111a. Inner wall of side wall; 112. Bottom wall; 113. Top wall; 114. Suction inlet; 115. Discharge outlet; 116. Liquid reservoir; 117. Suction pipe; 118. Oil reservoir; 200. Electric motor; 210. Gap; 220. Passage; 300. Stator; 310. Stator core; 310A, 310B. Stator core end face; 310b. Stator core outer peripheral surface; 311. Magnetic yoke; 312. Tooth; 313. Tooth base; 31 4, 315, Tooth base side; 316, Tooth tip; 317, Tooth tip face (stator core inner circumferential surface); 318, Slot; 319, Notch face; 320, Stator winding; 321, Winding section; 321U1, 321U2, U-phase winding section; 321V1, 321V2, V-phase winding section; 321W1, 321W2, W-phase winding section; 321a, Winding start section; 321b, Winding end section; 322, Overlap section (overlap wire); 400, 500, Electrical insulation assembly; 400A, 500 A. End face; 410, 510. Outer wall portion; 410a, 510a. Inner circumferential surface of outer wall portion; 410b. Outer circumferential surface of outer wall portion; 411A, 411B, 411C. Notch; 412A, 412B, 412C, 413A, 413B, 413C, 414A, 414B, 414C, 415A, 415B, 415C. Groove; 415Ba. Bottom surface; 416B, 416C. Protrusion; 420. Inner wall portion; 420a. Inner circumferential surface of inner wall portion; 420b. Outer circumferential surface of inner wall portion; 430. Main body; 431, 432, 531, 532, side of main body; 431a, 432a, 531a, 532a, guide groove; 433, top surface of main body; 440, 540, recess; 600, rotor; 610, rotor core; 610a, inner circumferential surface of rotor core; 610b, outer circumferential surface of rotor core; 620, permanent magnet; 630, end plate; 640, riveting pin; 650, rotating shaft; 700, compression mechanism; 710, cylinder; 720, eccentric rotor; 730, compression chamber; 740, 750, bearing. Detailed Implementation

[0082] The electric motors used in automotive air conditioning compressors mostly operate in environments below 150°C. Therefore, the motors need to withstand temperatures up to 150°C. For example, the permanent magnets mounted on the rotor must maintain their performance even at 150°C.

[0083] Here, the permanent magnets installed on the rotor of the electric motor are demagnetized due to the temperature rise caused by the increase in the driving current of the motor. As a result, the residual magnetic flux density of the permanent magnets decreases with the increase in the driving current of the motor. Furthermore, the residual magnetic flux density ratio can be regarded as the ratio (%) of the induced voltage when the motor is running to the induced voltage when there is no load (at room temperature).

[0084] Furthermore, when the temperature of the permanent magnet exceeds a specified value due to the increase in the drive current of the motor, the permanent magnet is irreversibly demagnetized. When the permanent magnet is irreversibly demagnetized, its magnetic properties will not be restored even if the temperature of the permanent magnet decreases. That is, the characteristics of the motor are degraded.

[0085] In motors where the phase windings (U-phase, V-phase, and W-phase windings) are star-connected, permanent magnets with coercivity ranging from 18,000 (Oe) to 26,500 (Oe) are used. When the operating temperature of the motor rises by more than 8°C compared to the set temperature, the permanent magnets irreversibly demagnetize.

[0086] On the other hand, when the phase windings are delta-connected, circulating current flows in the closed circuit formed by the phase windings. Due to this circulating current, the temperature of the permanent magnet may rise by more than 8°C.

[0087] Therefore, when the phase windings are delta-connected, it is necessary to suppress motor current while using permanent magnets that are used in star-connected phase windings, or to use permanent magnets with higher coercivity than those used in star-connected phase windings. For example, neodymium magnets with high coercivity, or neodymium magnets with a high content of at least one of terbium (Tb) and dysprosium (Dy). However, such permanent magnets with high coercivity are relatively expensive.

[0088] The inventors have conducted various studies on the following technology: when using the same permanent magnet as the one used in the case of star connection of phase windings, the permanent magnet is not irreversibly demagnetized even when the phase windings are delta connected.

[0089] The results showed that, when the phase windings were delta connected, the circulating current flowing in the closed circuit formed by the phase windings was largely caused by the deviation in the resistance values ​​of the phase windings.

[0090] Furthermore, it was found that by combining the structures described below, the deviation of the resistance values ​​of each phase winding can be reduced to a range where the circulating current flowing in the closed circuit will not cause irreversible demagnetization of the permanent magnet.

[0091] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0092] In this specification, the extension direction of axis P will be ( Figure 1 The X direction shown is called the "axial direction". When the rotor is rotatably mounted on the stator, the axis P corresponds to the center line of rotation of the rotor (rotation axis). Furthermore, Figure 1 The direction of arrow X1 is referred to as "the first side of the axis direction", and the direction of arrow X2 is referred to as "the second side of the axis direction".

[0093] The circumferential direction centered on axis P ( Figure 2 , Figure 3 The Y direction shown is called the "circumferential direction". Additionally, the view will be taken from the X1 side (the first side along the axis). Figure 1 time Figure 2 The direction of arrow Y1 is referred to as "circumferential first side", and the direction of arrow Y2 is referred to as "circumferential second side".

[0094] The direction of extension of the line passing through axis P when viewed from one side of the axis (Z direction) is called the "radial direction". Additionally, the direction along the radial direction (… Figure 6 The side of axis P (Z1 side) in the Z direction (as shown) is called the "radial inner side", and the side opposite to axis P in the radial direction (Z2 side) is called the "radial outer side". "Radial" varies depending on the position along the circumference.

[0095] Furthermore, for electrical insulator assemblies (first electrical insulator assembly, second electrical insulator assembly), terms such as "axial direction," "circumferential direction," and "radial direction" indicate the "axial direction," "circumferential direction," and "radial direction" of the electrical insulator assembly in the state of being disposed on the stator core.

[0096] First, refer to Figure 1 An embodiment of the compressor disclosed herein will be described. Figure 1 This is a cross-sectional view of a compressor 10 according to one embodiment.

[0097] also, Figure 1 The electric motor 200 shown is one embodiment of the electric motor disclosed herein.

[0098] The compressor 10 includes a sealed container 100, an electric motor 200, a compression mechanism 700, a liquid receiver 116, etc.

[0099] The sealed container 100 has a side wall portion 111, a bottom wall portion 112, and a top wall portion 113.

[0100] The electric motor 200 and the compression mechanism 700 are housed within the inner space of a sealed container. The compressor 10 of this embodiment is configured as a vertical compressor in which the electric motor 200 and the compression mechanism 700 are arranged in a vertical direction. Furthermore, it is configured as a vertical compressor in which the electric motor 200 is positioned above the compression mechanism 700. Alternatively, it can be configured as a vertical compressor in which the electric motor 200 is positioned below the compression mechanism 700.

[0101] On the sealed container 100, an intake port 114 is provided below the motor 200, and an exhaust port 115 is provided above the motor 200. In addition, an oil reservoir 118 is provided at the bottom of the sealed container 100 (below the compression mechanism 700) to store lubricating oil supplied to the sliding parts (e.g., bearing parts 740, 750) of the compression mechanism 700.

[0102] The compression unit 700 compresses the refrigerant that facilitates heat transfer. In this embodiment, a natural refrigerant with a low global warming coefficient (GWP), particularly non-toxic and non-flammable carbon dioxide, is used as the refrigerant. Of course, various refrigerants other than carbon dioxide can also be used. Furthermore, when using carbon dioxide as the refrigerant, the sealed container 170 experiences high temperature and high pressure compared to using Freon-based refrigerants. Therefore, a high-viscosity lubricant is used as the lubricant.

[0103] In this embodiment, a rotary compression mechanism is used as the compression mechanism 700. Of course, other compression mechanism structures can also be used.

[0104] The compression mechanism 700 includes a cylinder 710, an eccentric rotor 720 that rotates via a rotating shaft 650, and a compression chamber 730. The rotating shaft 650 is supported by bearings 740 and 750 to enable it to rotate.

[0105] When the eccentric rotor 720 of the compression mechanism 700 rotates due to the rotation of the rotating shaft 650, the refrigerant drawn in from the suction port 114 is compressed (pressurized) in the compression chamber 730.

[0106] The refrigerant compressed by the compression mechanism 700 is mixed with particulate lubricating oil. Then, the gas mixture containing the compressed refrigerant and particulate lubricating oil flows in the passage of the motor 200 and is ejected from the nozzle 115. The passage of the motor 200 includes the gap (air gap) between the stator core 310 and the rotor core 610, the stator passage formed in the stator core 310, and the rotor passage formed in the rotor core 610.

[0107] The receiver 116 separates the refrigerant and lubricating oil contained in the gas mixture ejected from the nozzle 115. The refrigerant separated from the gas mixture by the receiver 116 returns to the compressor section 700 via the suction pipe 117 and the suction port 114. In addition, the lubricating oil separated from the gas mixture by the receiver 116 returns to the oil reservoir 118.

[0108] Furthermore, the rotation of the rotating shaft 650 supplies lubricating oil stored in the oil reservoir 118 to the sliding parts of the compression mechanism 700. The lubricating oil, after lubricating the sliding parts of the compression mechanism 700, returns to the oil reservoir 118.

[0109] The mixed gas flowing above the motor 200 via the passageway of the motor 200 is cooled upon contact with the inner circumferential surface of the sealed container. As the mixed gas is cooled, a portion of the lubricating oil contained in the mixed gas is separated. The separated lubricating oil flows downward via the passageway of the motor 200 and returns to the oil reservoir 118.

[0110] Next, refer to Figures 1-6 The structure of the electric motor 200 will be described. Figure 2 Observing from the direction of arrow II-II Figure 1 A sectional view at that time. Figure 3 From Figure 1 The diagram shows the first electrical insulator assembly 400 viewed in the direction of arrow III. Figure 4 This is a perspective view of the first electrical insulator assembly 400. Figure 5 This is a diagram showing an example of the connection state of the first to third phase windings. Figure 6 This is a magnified view of the main parts.

[0111] The motor 200 in this embodiment is a permanent magnet motor including a stator 300 and a rotor 600.

[0112] The stator 300 has a stator core 310, electrical insulator assemblies 400 and 500, and stator windings 320.

[0113] The stator core 310 comprises a laminate formed by stacking multiple plate-shaped electromagnetic steel plates. The stator core 310 is formed into a cylindrical shape extending along the axial direction (X direction) and has an inner circumferential surface 317 and an outer circumferential surface 310b. The inner circumferential surface 317 is the tooth tip surface described later.

[0114] The inner circumferential surface 317 of the stator core forms an inner space with axis P as the center line. The rotor 600 (rotor core 610) is rotatably disposed within the inner space of the stator core.

[0115] In this embodiment, the stator core 310 is configured such that its axial direction (X direction) is parallel to the vertical direction (including "approximately parallel").

[0116] In addition, the stator core 310 has a stator core end face 310A on the first side (X1 side) in the axial direction (the upper side in this embodiment) and a stator core end face 310B on the second side (X2 side) in the axial direction (the lower side in this embodiment).

[0117] The stator core 310 has a magnetic yoke 311 and multiple teeth 312.

[0118] The magnetic yoke 311 extends circumferentially.

[0119] Multiple teeth 312 are arranged separately in the circumferential direction, extending radially inward (towards axis P) from the magnetic yoke 311.

[0120] Each tooth 312 has a tooth base 313 and a tooth tip 316.

[0121] The tooth base 313 extends radially inward from the yoke 311. The tooth base 313 has tooth base side surfaces 314 and 315 on its first circumferential side (Y1 side) and second circumferential side (Y2 side), respectively. In this embodiment, the tooth base side surfaces 314 and 315 extend parallel (including "generally parallel") to the tooth centerline e of the tooth 312. The tooth centerline e is a line passing through the circumferential center of the tooth 312 (tooth base 313) and the axis P. Therefore, the winding portion 321 (described later) can be arranged and wound around the tooth base 313, reducing the deviation in the resistance value of the winding portion 321.

[0122] A tooth tip portion 316 is provided at the tip portion radially inner to the tooth base portion 313 and extends circumferentially. A tooth tip surface 317 is formed on the radially inner side of the tooth tip portion 316. The tooth tip surface 317 forms the inner space of the stator core. That is, the tooth tip surface 317 forms the inner circumferential surface of the stator core.

[0123] The groove 318 is formed by adjacent teeth 312 in the circumferential direction.

[0124] Furthermore, the number of teeth 312 (grooves 318) can be appropriately selected.

[0125] In this embodiment, the stator core 310 is disposed in the inner space of the sealed container with its outer peripheral surface 310b abutting against the inner peripheral surface 111a of the side wall portion 111.

[0126] In this embodiment, a plurality of notched surfaces 319 extending along the axial direction are formed on the outer peripheral surface 310b of the stator core. A passage 220 extending along the axial direction is formed by the inner peripheral surface 111a of the sidewall portion and the notched surfaces 319. The passage 220 is used as a stator passage for the flow of refrigerant (mixed gas).

[0127] The rotor 600 includes a rotor core 610 and a rotating shaft 650.

[0128] The rotor core 610 includes a laminate formed by stacking multiple plate-shaped electromagnetic steel plates. End plates 630 are arranged on both sides of the laminate in the axial direction. The laminate is formed with the electromagnetic steel plates aligned by inserting rivet pins 640 into rivet pin insertion holes formed in each electromagnetic steel plate and the end plates 630.

[0129] The rotor core 610 has a plurality of permanent magnets 620. Typically, the permanent magnets 620 are inserted into magnet insertion holes (not shown) that extend axially in the rotor core 610. As permanent magnets 620, rare earth magnets, such as neodymium magnets, neodymium magnets diffused with dysprosium (Dy) and terbium (Tb), etc., are used.

[0130] The magnetic poles of the rotor 600 are formed by permanent magnets 620. Furthermore, Figure 2 The number, shape, and arrangement of the permanent magnets are illustrated illustratively. The number of poles of the rotor 600 can be appropriately selected (e.g., 4 poles, 6 poles, 12 poles). Furthermore, the shape of the permanent magnets 620 forming each pole can be appropriately selected (e.g., straight shape, curved shape). Additionally, the number and arrangement of the permanent magnets 620 in each pole can be appropriately selected (e.g., arranging two straight-shaped permanent magnets 620 in a letter V shape, or arranging three straight-shaped permanent magnets 620 in a trapezoidal shape).

[0131] Preferably, the number of slots 318 (teeth 312) in the stator core 310 and the number of magnetic poles in the rotor 600 are set in an appropriate relationship.

[0132] In addition, a passage (rotor passage) extending along the axial direction can also be provided in the rotor core 610.

[0133] The rotating shaft 650 is inserted into the rotating shaft insertion hole formed by the inner circumferential surface 610a of the rotor core by pressing or other means. A gap (air gap) 210 is formed between the outer circumferential surface 610b of the rotor core and the inner circumferential surface 317 of the stator core.

[0134] Electrical insulator assemblies 400 and 500 are formed from resins with insulating properties.

[0135] Electrical insulator assemblies 400 and 500 are arranged on both sides of the stator core 310 along its axial direction. Figure 1 In this configuration, the electrical insulator assembly 400 is disposed on the first side of the stator core 310 along its axial direction, and the electrical insulator assembly 500 is disposed on the second side of the stator core 310 along its axial direction. At this time, the end face 400A of the electrical insulator assembly 400 is opposite to the end face 310A of the stator core, and the end face 500A of the electrical insulator assembly 500 is opposite to the end face 310B of the stator core.

[0136] In this embodiment, the electrical insulator assembly 400 corresponds to the "first electrical insulator assembly" of the present invention, and the electrical insulator assembly 500 corresponds to the "second electrical insulator assembly" of the present invention.

[0137] In this embodiment, the electrical insulator assemblies 400 and 500 have the same shape. Therefore, hereinafter, reference will be made to... Figure 3 , Figure 4 The electrical insulator assembly 400 is described below.

[0138] exist Figure 4 In the figure, the reference numerals of each element of the electrical insulator assembly 500 are shown in correspondence with the elements of the electrical insulator assembly 400.

[0139] Electrical insulator assemblies 400 and 500 are arranged in opposite directions along their axial axes. Therefore, the first side, second side, first circumferential side, and second circumferential side of electrical insulator assembly 500 are respectively opposite to... Figure 3 , Figure 4 The axial direction second side, axial direction first side, circumferential direction second side and circumferential direction first side of the electrically insulating assembly 400 shown correspond to each other.

[0140] Furthermore, the positions of the winding start portion 321a and the winding end portion 321b of the winding portion 321 described below can be either the first side (X1 side) or the second side (X2 side) in the axial direction. Additionally, the portion where the overlapping portion 322 connecting the winding portion 321 is disposed can be either the first side (X1 side) or the second side (X2 side) in the axial direction.

[0141] The following description addresses the case where the winding start portion 321a and the winding end portion 321b are positioned on the first side (X1 side) in the axial direction, and an overlap portion 322 is also provided on the first side (X1 side) in the axial direction. In this case, in the electrical insulator assembly 500 positioned on the second side (X2 side) in the axial direction, the multiple notches and slots corresponding to the multiple notches 411A to 411C and the multiple slots 412A to 412C of the electrical insulator assembly 400 can be omitted.

[0142] The electrical insulator assembly 400 has an outer wall portion 410, a plurality of inner wall portions 420, and a plurality of main sections 430. The electrical insulator assembly 400 has an end face 400A on a second side in the axial direction (the side opposite to the stator core 310).

[0143] The outer wall portion 410 extends along the circumferential and axial directions and has an inner circumferential surface 410a, an outer circumferential surface 410b, and an end face 410B. The end face 410B is formed on the side opposite to the end face 400A along the axial direction (the side opposite to the stator core). The outer wall portion 410 is configured to face the yoke 311 of the stator core 310.

[0144] In addition, the outer wall portion 410 has multiple notches 411A to 411C and multiple grooves 412A to 412C.

[0145] Multiple notches 411A to 411C are arranged separately in the circumferential direction. Each notch 411A to 411C opens toward a first side in the axial direction (the side opposite to the stator core 310), a radially inward side (inner circumferential surface 410a of the outer wall portion), and a radially outward side (outer circumferential surface 410b of the outer wall portion). The notches 411A to 411C are formed to allow the wire 320a forming the winding portion 321 (described later) to pass through from the radially inward side to the radially outward side of the outer wall portion 410, and also from the radially outward side to the radially inward side.

[0146] In this embodiment, the plurality of notches 411A to 411C include a first group of notches 411A, a second group of notches 411B, and a third group of notches 411C. In this embodiment, the depth of the second group of notches 411B is set to be greater than the depth of the first group of notches 411A and less than the depth of the third group of notches 411C ([depth of the first group of notches 411A < depth of the second group of notches 411B < depth of the third group of notches 411C]). The first to third groups of notches 411A to 411C each have bottom surfaces 411a to 411c.

[0147] Multiple slots 412A to 412C are separately arranged on the outer peripheral surface 410b of the outer wall portion in the axial direction and extend circumferentially. Each slot 412A to 412C is open at one of the notches 411A to 411C on the outer peripheral surface 410b of the outer wall portion. The slots (412A to 412C) are formed to allow the insertion of the wire 320a that forms the overlapping part 322 (described later).

[0148] In this embodiment, the plurality of slots 412A to 412C include a first group of slots 412A disposed on the side opposite to the end face 400A (the side opposite to the stator core 310), a third group of slots 412C disposed on the side of the end face 400A (the side of the stator core 310), and a second group of slots 412B disposed between the first group of slots 412A and the third group of slots 412C.

[0149] The overlapping portion 322 (wire 320a) provided via the first set of slots 412A passes through one and the other gaps in the first set of gaps 411A. The overlapping portion 322 (wire 320a) provided via the second set of slots 412B passes through one and the other gaps in the second set of gaps 411B. The overlapping portion 322 (wire 320a) provided via the third set of slots 412C passes through one and the other gaps in the third set of gaps 411C.

[0150] By separately providing the first to third sets of grooves 412A to 412C in the axial direction, it is possible to prevent the multiple overlapping portions 322 arranged along the circumferential direction from contacting each other.

[0151] Multiple inner wall portions 420 are arranged radially inward from the outer wall portion 410, separated in the circumferential direction. Each inner wall portion 420 extends in both the circumferential and axial directions and has an inner circumferential surface 420a and an outer circumferential surface 420b. Each inner wall portion 420 is arranged opposite to the tooth tip portion 316 of the stator core 310.

[0152] Each main stem 430 extends circumferentially and radially, connecting the outer wall portion 410 and each inner wall portion 420. Each main stem 430 is configured to face each tooth base 313 of the stator core 310.

[0153] like Figure 6 , Figure 7 As shown, each main stem 430 has a main stem side surface 431 disposed on the first circumferential side (Y1 side), a main stem side surface 432 disposed on the second circumferential side (Y2 side), and a main stem top surface 433 disposed on the first axial side (the side opposite to the stator core 310).

[0154] Each main stem 430 has multiple guide grooves 431a formed at the connection between the main stem side surface 431 and the main stem top surface 433. The multiple guide grooves 431a are arranged radially separately. Each guide groove 431a extends circumferentially.

[0155] In addition, each main stem 430 has multiple guide grooves 432a formed at the connection between the main stem side surface 432 and the main stem top surface 433. The multiple guide grooves 432a are arranged radially separately. Each guide groove 432a extends circumferentially.

[0156] The shapes and radially arranged positions of the guide grooves 431a and 432a are configured such that the winding portions 321 are arranged and wound around the teeth 312 (tooth base 313). Furthermore, by arranging and winding the first turn (the innermost portion) of the winding portions 321, overlap of the wires 320a can be prevented, and the winding portions 321 are arranged and wound in a specific order. In this embodiment, the winding position and winding direction of the first turn of the wire 320a can be guided using the multiple guide grooves 431a and 432a, thus making it easy to arrange and wind the first turn.

[0157] By arranging and winding each winding portion 321, the deviation in the length of the wire 320a forming each winding portion 321 can be reduced, thereby reducing the deviation in the resistance value of each winding portion 321.

[0158] In this embodiment, the main stem side 431 corresponds to the "first main stem side" of the present invention, and the main stem side 432 corresponds to the "second main stem side" of the present invention. Additionally, the guide groove 431a corresponds to the "first guide groove" of the present invention, and the guide groove 432a corresponds to the "second guide groove" of the present invention.

[0159] The stator winding 320 includes multiple phase windings. Each phase winding has multiple winding portions 321 and at least one overlap portion 322 connecting the winding portions 321. The multiple winding portions of each phase winding are connected in series and in parallel in a suitable combination.

[0160] Figure 5 This represents an example of a stator winding of 320.

[0161] exist Figure 5 In the stator winding 320, there are U-phase winding, V-phase winding and W-phase winding connected by delta connection.

[0162] The U-phase winding has two U-phase winding portions 321U1 and 321U2 and a U-phase overlapping portion 322U1 connecting the U-phase winding portions 321U1 and 321U2.

[0163] The V-phase winding has two V-phase winding sections 321V1 and 321V2 and a V-phase overlap section 322V1 connecting the V-phase winding sections 321V1 and 321V2.

[0164] The W-phase winding has two W-phase winding portions 321W1 and 321W2 and a W-phase overlapping portion 322W1 connecting the W-phase winding portions 321W1 and 321W2.

[0165] exist Figure 5 In this configuration, the winding sections of each phase winding are connected in series.

[0166] When the U-phase winding, V-phase winding, and W-phase winding are delta-connected, the circulating current Ia caused by the deviation in the resistance values ​​of each phase winding flows in the closed circuit formed by the U-phase winding, V-phase winding, and W-phase winding (refer to...). Figure 5 ).

[0167] The motor 200 of this embodiment reduces the circulating current caused by the deviation in the resistance values ​​of each phase winding by reducing the deviation in the resistance values ​​of each phase winding.

[0168] The U-phase to W-phase windings correspond to the "first to third phase windings" of this invention.

[0169] With the outer wall portions 410 and 510 of the electrical insulator assemblies 400 and 500 and the plurality of main stems 430 and 530 respectively arranged on both sides of the axial direction of the stator core 310 opposite to the magnetic yoke 311 and the plurality of tooth base portions 313, each winding portion 321 is wound around each tooth base portion 313.

[0170] Each winding portion 321 is formed by winding an electric wire 320a. The electric wire 320a includes a conductor made of a conductive material such as copper and an insulating covering portion made of an insulating material and disposed around the conductor.

[0171] In this embodiment, each winding portion 321 is wound around each tooth base 313 in such a manner that it begins to wind from the radially outer side (outer wall portion 410 side) and ends to wind from the radially outer side (outer wall portion 410 side) (see reference). Figure 3 , Figure 4 That is, each winding portion 321 is wound with the winding start portion 312a and the winding end portion 312b arranged radially outward.

[0172] By arranging the winding start portion 321a and winding end portion 321b of each winding portion 321 on the radially outer side, the deviation in the length of the wire 320a forming each winding portion 321, i.e. the deviation in the resistance value of each winding portion 321, can be reduced.

[0173] Furthermore, by arranging the winding start portion 321a and winding end portion 321b of each winding portion 321 radially outward, the deviation in the length of the overlap portion 322 connecting the two winding portions 321 (connecting the winding end portion 321b of one winding portion 321 and the winding start portion 321a of the other winding portion 321) can be reduced, that is, the deviation in the resistance value of each overlap portion 322.

[0174] Furthermore, in this embodiment, the plurality of winding portions 321 and at least one overlapping portion 322 included in the same phase winding are formed by a continuous single wire 320a. That is, there is no connection between the winding end portion 321b and the overlapping portion 322, and between the overlapping portion 322 and the winding start portion 321a.

[0175] As a result, the deviation in resistance value at the connection point disappears, thus preventing the deviation in resistance value of each phase winding caused by the deviation at the connection point.

[0176] The following is about the formation Figure 5 The case of the U-phase winding, including the U-phase winding portion 321U1, the U-phase winding portion 321U2 and the U-phase overlap portion 322U1, will be explained.

[0177] First, a wire 320a is wound around the tooth base 313 of one of the multiple teeth 312 used for the U-phase. At this time, on the circumferential first side, winding begins from the radially outer winding start portion 321a, and on the circumferential second side, winding ends at the radially outer winding end portion 321b. Thus, the U-phase winding portion 321U1 is formed.

[0178] Next, the wire 320a is led out from the winding end portion 321b of the U-phase winding portion 321U1 through one of the multiple notches 411A to 411C formed in the outer wall portion 410 from the radial inside to the radial outside.

[0179] Next, the wire 320a, which is led out to the radially outer side of the outer wall portion 410, is arranged circumferentially through one of the multiple slots 412A to 412C formed on the outer peripheral surface 410b of the outer wall portion.

[0180] Next, the wire 320a is led back from the radially outer side to the radially inner side of the outer wall portion 410 through another of the multiple notches 411A to 411C.

[0181] Next, the wire 320a is wound around the tooth base 313 of another tooth 312 among the multiple teeth 312 for the U-phase. At this time, on the first circumferential side, winding begins from the radially outer winding start portion 321a, and on the second circumferential side, winding ends at the radially outer winding end portion 321b. Thus, the U-phase winding portion 321U2 is formed, and the U-phase overlap portion 322U1 connecting the U-phase winding portions 321U1 and 321U2 is formed.

[0182] Furthermore, in this embodiment, the arrangement positions of the multiple notches 411A to 411C are set such that the lengths of each overlapping portion 322 along the circumferential direction are approximately equal. The length of the overlapping portion 322 along the circumferential direction is the length along the circumferential direction between one notch (411A to 411C) through which the overlapping portion 322 extends from the radially inner side to the radially outer side of the outer wall portion 410 and another notch (411A to 411C) through which the overlapping portion 322 extends back from the radially outer side to the radially inner side of the outer wall portion 410.

[0183] In this embodiment, by leading the wires 320a forming each overlap portion 322 out radially from the radially inner side to the radially outer side of the outer wall portion 410 through one of the multiple notches 411A to 411C, and leading them back from the radially outer side to the radially inner side of the outer wall portion through another of the multiple notches 411A to 411C, the deviation in the length of the circumferentially arranged portion of each overlap portion 322, i.e., the deviation in the resistance value of each overlap portion 322, can be reduced.

[0184] This reduces the deviation in resistance values ​​of each phase winding (U-phase winding, V-phase winding, W-phase winding) caused by the deviation in resistance values ​​of each overlapping part 322.

[0185] like Figure 3 , Figure 4 As shown, the winding start portion 321a (winding end portion 321b) of the winding portion 321 passes through one of the three groups of slots: the first group of slots 412A, the second group of slots 412B, and the third group of slots 412C.

[0186] Here, the first set of slots 412A, the second set of slots 412B, and the third set of slots 412C are separately arranged on the outer peripheral surface 410b of the outer wall portion in the axial direction. Therefore, the length of the winding start portion 321a (winding end portion 321b) along the axial direction varies depending on the slot through which the winding start portion 321a (winding end portion 321b) passes. That is, the resistance value of the winding start portion 321a (winding end portion 321b) of each winding portion 321 deviates.

[0187] The resistance values ​​of each phase winding are affected by the deviation in the resistance value of the winding start part 321a (winding end part 321b).

[0188] Therefore, it is preferable to reduce the deviation of the resistance value of the winding start portion 321a (winding end portion 321b) of each phase winding.

[0189] As a method to reduce the deviation of the resistance value of the winding start portion 321a (winding end portion 321b) of each phase winding, it is possible to use a method of changing the shape of the plurality of grooves 412A to 412C formed on the outer peripheral surface 410b of the outer wall portion.

[0190] Figure 8 This illustrates an example where the shape of the multiple grooves 412A to 412C formed on the outer peripheral surface 410b of the outer wall portion has been changed.

[0191] exist Figure 8 In the middle, the outer peripheral surface 410b of the outer wall extends parallel (including "generally parallel") to the axial direction.

[0192] In addition, the plurality of grooves 413A to 413C formed on the outer peripheral surface 410b of the outer wall portion include a first group of grooves 413A, a second group of grooves 413B, and a third group of grooves 413C separated in the axial direction.

[0193] The depths of the first to third groups of grooves 413A to 413C are different. That is, the depth r2 of the second group of grooves 413B is configured to be smaller than the depth r1 of the first group of grooves 413A formed on the side opposite to the stator core 310 and larger than the depth r3 of the third group of grooves 413C formed on the side of the stator core 310. In other words, it is set to satisfy [r3 < r2 < r1].

[0194] Therefore, the resistance value deviation caused by the height difference along the axial direction of each winding start portion 321a (winding end portion 321b) can be compensated by utilizing the resistance value deviation caused by the difference in radial arrangement position (difference in radial length) of each overlapping portion 322.

[0195] The depths r1 to r3 are set to appropriate values ​​that can compensate for the deviation of the resistance value of the winding start portion 321a (winding end portion 321b) of each phase winding.

[0196] Figure 9 This is another example of changing the shape of multiple grooves formed on the outer peripheral surface 410b of the outer wall portion.

[0197] exist Figure 9 In the middle, the outer peripheral surface 410b of the outer wall portion extends obliquely relative to the axis in such a way that the end opposite to the end face 400A (the side opposite to the stator core 310) along the axial direction is located radially inward of the end on the end face 400A side (the stator core 310 side).

[0198] In addition, the plurality of grooves 414A to 414C formed on the outer peripheral surface 410b of the outer wall portion include a first group of grooves 414A, a second group of grooves 414B, and a third group of grooves 414C separated in the axial direction.

[0199] The first to third groups of grooves 414A to 414C are formed to have equal depths (including "approximately equal"). That is, they are configured to satisfy the following: [the depth s1 of the first group of grooves 414A = the depth s2 of the second group of grooves 414B = the depth s3 of the third group of grooves 414C].

[0200] Therefore, the resistance value deviation caused by the height difference along the axial direction of each winding start portion 321a (winding end portion 321b) can be compensated by utilizing the resistance value deviation caused by the difference in radial arrangement position (difference in radial length) of each overlapping portion 322.

[0201] Figure 10 This is another example of changing the shape of multiple grooves formed on the outer peripheral surface 410b of the outer wall portion.

[0202] exist Figure 10 In the middle, the outer peripheral surface 410b of the outer wall extends parallel (including "generally parallel") to the axial direction.

[0203] In addition, the plurality of grooves 415A to 415C formed on the outer peripheral surface 410b of the outer wall portion include a first group of grooves 415A, a second group of grooves 415B, and a third group of grooves 415C separated in the axial direction.

[0204] The first to third groups of grooves 415A to 415C are formed to have equal depths (including "approximately equal").

[0205] Furthermore, a protrusion 416B is formed in the second groove 415B, and a protrusion 416C is formed in the third groove 415C.

[0206] The protrusions 416B and 416C are configured such that the minimum interval t2 between the protrusion 416B and the outer peripheral surface 410b of the outer wall portion is larger than the minimum interval t3 between the protrusion 416C and the outer peripheral surface 410b of the outer wall portion and smaller than the depth t1 of the first group of grooves 415A.

[0207] That is, the protrusions 416B and 416C are formed to satisfy [t3 < t2 < t1].

[0208] For example, such as Figure 11 As shown, a protrusion 416B extending circumferentially is formed on the bottom surface 415Ba of groove 415B. A protrusion extending circumferentially in the same manner as the protrusion 416B is also formed on the bottom surface of groove 415C (illustration omitted).

[0209] Or, such as Figure 12 As shown, a plurality of protrusions 417B that are separated in the circumferential direction are formed on the bottom surface 415Ba of groove 415B. Protrusions that are separated in the circumferential direction in the same manner as the protrusions 417B are also formed on the bottom surface of groove 415C (illustration omitted).

[0210] Therefore, the resistance value deviation caused by the height difference along the axial direction of each winding start portion 321a (winding end portion 321b) can be compensated by utilizing the resistance value deviation caused by the difference in radial arrangement position (difference in radial length) of each overlapping portion 322.

[0211] Protrusions 416B and 417B correspond to "at least one first protrusion" of the present invention. Protrusion 416C corresponds to "at least one second protrusion" of the present invention.

[0212] exist Figure 11 and Figure 12 In the embodiment shown, at least (n-1) of the n grooves that are axially separated on the outer peripheral surface 410b of the outer wall portion have at least one protrusion formed on their bottom surfaces in a manner that varies for each groove, with a minimum depth from the outer peripheral surface 410b of the outer wall portion.

[0213] Furthermore, wire 320a is configured to meet the following conditions.

[0214] The diameter of the conductors included in the wire 320a is managed to be within the range of ±0.002 mm to ±0.03 mm relative to the conductor diameter setting.

[0215] This reduces the deviation in resistance values ​​of each phase winding.

[0216] In addition, the diameter of wire 320a is managed to be within the range of ±0.018mm to ±0.17mm relative to the wire diameter setting.

[0217] When the wire diameter deviates, the resistance value also deviates. Furthermore, when the wire diameter deviates, the circumference of the winding portion 321 formed by winding the wire 320a around the teeth 312 deviates, thus causing a deviation in the resistance value. However, the deviation in wire diameter can also be reduced by decreasing the deviation in the thickness of the insulating film surrounding the conductor.

[0218] Therefore, while guiding the wire 320a using the multiple first and second guide grooves 431a, 432a (531a, 532a) formed in the main stems 430, 530 of the first and second electrical insulator assemblies 400, 500, the winding portions 321 can be arranged and wound, so that the difference in resistance value of each phase winding is within ±3%.

[0219] In the motor 200 of this embodiment, by combining the above-described structures, the deviation of the resistance values ​​of each phase winding (U-phase winding, V-phase winding, W-phase winding) connected in a delta configuration can be reduced to within ±3%.

[0220] Therefore, the circulating current flowing in the closed circuit formed by the phase windings connected in a delta configuration can be reduced to a value that does not cause the temperature of the permanent magnet to rise by more than 8°C at an ambient temperature of 150°C.

[0221] Furthermore, since the temperature of the permanent magnet will not rise by more than 8°C due to the circulating current when the ambient temperature is 150°C, permanent magnets with a coercivity in the range of 18000 (Oe) to 26500 (Oe) can be used when the phase windings (U phase winding, V phase winding, W phase winding) are connected in a star configuration.

[0222] Furthermore, the structures described above are effective for motors 200 used in the range of 50mm to 240mm outer diameter of stator 300 (stator core 310), 30mm to 144mm inner diameter, 6 (6 slots) to 36 (36 slots) number of slots 318, and DC12V to 800V voltage (power supply voltage).

[0223] The electric motor and compressor disclosed herein are not limited to the structures described in the embodiments, and various changes, additions, and deletions can be made.

[0224] In the embodiments, a vertical compressor in which the motor and the compression mechanism are arranged in the vertical direction has been described, but the compressor of this disclosure can also be configured as a horizontal compressor in which the motor and the compression mechanism are arranged in the horizontal direction.

[0225] The structure of the stator (e.g., the number of teeth, the shape of the teeth, the number of phase winding portions included in the phase winding, the connection method, the number of winding portions, and the number of overlapping portions) is not limited to the structure described in the embodiments.

[0226] The structure of the rotor (e.g., the number of permanent magnets, the shape of the permanent magnets, and the arrangement of the permanent magnets) is not limited to the structure described in the embodiments.

[0227] The structure of the electrical insulator assembly (e.g., the shape of the outer wall, inner wall, and main body, the number and shape of the notches) is not limited to the structure described in the embodiments.

[0228] It also eliminates the need for structures used to reduce the resistance deviation at the beginning and end of winding. Figures 8-12 (The structure shown).

[0229] The structures described in the embodiments can be used individually or in combination with appropriately selected structures.

Claims

1. An electric motor, which is housed together with a compression mechanism within a sealed container, characterized in that, The electric motor includes a rotor and a stator. The rotor includes a rotor core with multiple permanent magnets, and the rotor is supported to rotate relative to the stator. The stator includes a stator core, a first electrical insulator assembly, a second electrical insulator assembly, and stator windings. The stator core has: a magnetic yoke formed as a cylinder extending along the axial direction and extending circumferentially; and a plurality of teeth arranged separately in the circumferential direction and extending radially inward from the magnetic yoke. The first electrical insulator assembly and the second electrical insulator assembly each have an outer wall portion that extends along the circumferential direction; Multiple inner wall portions are arranged separately in the circumferential direction at a position radially inward than the outer wall portions and extend along the circumferential direction; And multiple main branches, which are disposed between each of the inner wall portions and the outer wall portions, and extend radially. The first electrical insulator assembly and the second electrical insulator assembly are respectively disposed on the first side and the second side of the stator core in the axial direction. At least one of the first and second electrical insulator assemblies has a plurality of notches and a plurality of grooves on its outer wall portion. The plurality of notches are arranged separately in the circumferential direction, and each notch opens on the side opposite to the stator core along the axial direction, on the inner circumferential surface of the outer wall portion and on the outer circumferential surface of the outer wall portion. The plurality of grooves are separately arranged on the outer peripheral surface of the outer wall portion in the axial direction, each groove extending along the circumferential direction and opening in the radially outer side, at one of the plurality of notches and at the other notch. The stator windings include a first phase winding to a third phase winding connected in a delta configuration. Each phase winding has multiple winding portions and at least one overlapping portion. With the first electrical insulator assembly and the second electrical insulator assembly respectively arranged on the first and second sides of the stator core in the axial direction, such that their outer wall portions and the plurality of main stems are respectively opposite to the magnetic yoke and the plurality of teeth, each of the winding portions is wound around the teeth. The at least one overlap portion extends outward from one of the plurality of winding portions via one of the plurality of notches in the outer wall portion of the at least one electrical insulator assembly, is disposed circumferentially via at least one of the plurality of grooves in the outer wall portion, and extends back inward from the outer wall portion via another of the plurality of notches in the outer wall portion. Each of the aforementioned teeth has the following tooth base: a first tooth base side surface disposed on a circumferential first side and extending parallel to the tooth centerline; and a second tooth base side surface disposed on a circumferential second side and extending parallel to the tooth centerline. The plurality of winding portions and the at least one overlapping portion of each of the first to third phase windings are formed by a single continuous wire. The winding portions of each of the first to third phase windings begin winding from the radially outer side and end winding from the radially outer side. Each of the main stems of the first and second electrical insulator assemblies has: a first main stem side surface disposed on a circumferential first side and extending parallel to the tooth centerline of the tooth opposite to the main stem; a second main stem side surface disposed on a circumferential second side and extending parallel to the tooth centerline; a main stem top surface disposed on a side opposite to the stator core along the axial direction; a plurality of first guide grooves formed radially separately at the connection portion connecting the first main stem side surface and the main stem top surface; and a plurality of second guide grooves formed radially separately at the connection portion connecting the second main stem side surface and the main stem top surface, wherein the plurality of first guide grooves and the plurality of second guide grooves extend circumferentially. The circumferential lengths of the overlapping portions of the first to third phase windings are configured to be approximately equal. The resistance difference between the first phase winding and the third phase winding is configured to be within ±3%.

2. The electric motor according to claim 1, characterized in that, The plurality of gaps are configured such that the portion of at least one overlap of the first phase winding to the third phase winding, located between one of the gaps and another of the gaps, has approximately equal length along the circumferential direction.

3. The electric motor according to claim 1 or 2, characterized in that, As the permanent magnet, a permanent magnet with a coercivity in the range of 18000 Oe to 26500 Oe is used.

4. The electric motor according to claim 1 or 2, characterized in that, When the ambient temperature around the motor is lower than 150°C, the temperature rise of the permanent magnet is suppressed to within 8°C.

5. The electric motor according to claim 1 or 2, characterized in that, The wire is formed by conductors and an insulating covering disposed around the conductors. The diameter of the conductor is within the range of ±0.002 mm to ±0.03 mm relative to the set conductor diameter value. The diameter of the wire is within the range of ±0.018 mm to ±0.17 mm relative to the wire diameter setting value.

6. The electric motor according to claim 1 or 2, characterized in that, The outer peripheral surface of the outer wall portion of the at least one electrical insulator assembly extends parallel to the axial direction. The plurality of slots includes: a first group of slots disposed on the side opposite to the stator core; a third group of slots disposed on the stator core side; and a second group of slots disposed between the first group of slots and the third group of slots. The depth of the second set of grooves is configured to be greater than the depth of the third set of grooves and less than the depth of the first set of grooves.

7. The electric motor according to claim 1 or 2, characterized in that, The outer peripheral surface of the outer wall portion of the at least one electrical insulator assembly extends obliquely relative to the axial direction, with its end on the side opposite to the stator core positioned radially inward than the end on the stator core side. The plurality of slots includes: a first group of slots disposed on the side opposite to the stator core; a third group of slots disposed on the stator core side; and a second group of slots disposed between the first group of slots and the third group of slots. The depths of the first to third groups of grooves are equal.

8. The electric motor according to claim 1 or 2, characterized in that, The outer peripheral surface of the outer wall portion of the at least one electrical insulator assembly extends parallel to the axial direction. The plurality of slots includes: a first group of slots disposed on the side opposite to the stator core; a third group of slots disposed on the stator core side; and a second group of slots disposed between the first group of slots and the third group of slots. At least one first protrusion is formed on the bottom surface of the second set of grooves. At least one second protrusion is formed on the bottom surface of the third set of grooves. The minimum interval between the first protrusion and the outer peripheral surface of the outer wall portion is configured to be larger than the minimum interval between the second protrusion and the outer peripheral surface of the outer wall portion and smaller than the depth of the first set of grooves.

9. A compressor comprising: a compression mechanism; an electric motor for driving the compression mechanism; and a sealed container housing the compression mechanism and the electric motor. The compressor is characterized in that, The electric motor described in claim 1 or 2 is used as the electric motor.

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