Electric motor and compressor

Abstract

The invention provides a motor and a compressor. The electrical insulator includes: a first outer wall portion disposed on a first side in the axial direction of the yoke; a first main body section disposed on a first side of the tooth base section in the axial direction; and a first inner wall portion disposed on a first axial side of the tooth tip portion. The first body portion includes a first side surface on a first side in a circumferential direction and a second side surface on a second side in the circumferential direction. The electrical insulator is provided with a protruding part which is formed at a connection part between the first main body part and the first outer wall part, and which has an inclined wall surface connected to the inner peripheral surface of the first outer wall part and the first side surface. The stator core includes at least one of a recessed cutout portion formed in at least one of the tooth second side surface and the yoke inner peripheral surface and a tooth protruding portion formed in a connection portion between the tooth first side surface and the yoke inner peripheral surface.

Description

Technical Field

[0001] The present disclosure relates to electric motors and compressors. Background Art

[0002] A known concentrated winding electric motor is equipped with a concentrated winding stator. The stator includes an electrical insulator that insulates the stator core from the stator windings wound around the teeth of the stator core. The stator comprises a circumferentially extending yoke, a plurality of teeth extending radially from the yoke, and a plurality of slots defined by adjacent teeth. The teeth have a tooth base extending radially inward from the yoke and a tooth tip disposed at the tip of the tooth base and extending circumferentially. For example, Japanese Patent Application Laid-Open No. 2002-272045 discloses a stator having an inclined surface formed on the first axial side of the tooth base. This allows the stator winding to be wound while sliding radially outward along the inclined surface formed on the tooth base. Summary of the Invention

[0003] However, in conventional technologies, stator windings are sometimes wound crosswise, which can reduce the slot fill factor of the stator windings within the slots. Furthermore, in recent years, the stator core and the electrical insulator are sometimes integrally formed through insert molding. Therefore, there is a need for a technology that reduces defects in insert molding of resin materials and improves the slot fill factor of the stator windings within the slots.

[0004] The present disclosure can be implemented in the following forms.

[0005] (1) According to one embodiment of the present disclosure, an electric motor having a stator and a rotor is provided. The stator includes a stator core, an electrical insulator, and a stator winding. The stator core has a cylindrical shape extending in the axial direction. The stator core has a yoke extending in the circumferential direction and a plurality of teeth extending radially inward from the yoke. The teeth include: a tooth base extending radially inward from the yoke; and a tooth tip connected to the radially inner tip of the tooth base. The tooth base includes a tooth first side surface on the first circumferential side and a tooth second side surface on the second circumferential side. The electrical insulator includes: a first outer wall portion arranged on the first axial side of the yoke; a first main body portion arranged on the first axial side of the tooth base; and a first inner wall portion arranged on the first axial side of the tooth tip portion. The first main body portion includes a first side surface on the first circumferential side and a second side surface on the second circumferential side. The stator winding is wound around at least the tooth base portion in a state where the first main body portion is arranged on the first axial side of the tooth base portion. The electrical insulator includes a protrusion portion formed at a connection portion between the first main body portion and the first outer wall portion, and having an inclined wall surface connected to the inner peripheral surface of the first outer wall portion and the first side surface. The stator core includes at least one of a notch portion and a tooth protrusion portion, the notch portion being formed at at least one of the second side surface of the tooth and the inner peripheral surface of the yoke, and having a concave shape facing the side opposite to the slot defined by the circumferentially adjacent teeth, and the tooth protrusion portion being formed at a connection portion between the first side surface of the tooth and the inner peripheral surface of the yoke, and protruding toward the slot.

[0006] According to this embodiment of the electric motor, even when the electrical insulator having the protruding portion is formed by insert molding, the flow rate balance of the resin material between the first side surface and the second side surface can be appropriately set. Therefore, molding defects such as short shots during insert molding of the electrical insulator can be reduced or prevented.

[0007] (2) In the motor of the above embodiment, the stator core may include the notch. The notch may be provided at the connection between the second side surface of the tooth and the inner peripheral surface of the yoke. The notch may have a concave shape including a first portion formed on the inner peripheral surface of the yoke and a second portion formed on the second side surface of the tooth.

[0008] According to the electric motor of this aspect, compared with a case where the notches are provided on the inner peripheral surface of the yoke and the second side surface of the teeth, the flow rate of the resin material in the notches during insert molding can be increased.

[0009] (3) In the electric motor of the above aspect, the notch portion may include a curved portion having a curvature smaller than a curvature of a connection portion between the inner peripheral surface of the yoke and the first side surface of the tooth.

[0010] According to the electric motor of this aspect, the flow path resistance of the notch portion can be reduced, and the flow rate of the resin material in the notch portion during insert molding can be increased.

[0011] (4) In the electric motor according to the above aspect, the cross-sectional area of the protrusion and the cross-sectional area of the notch may be different from each other.

[0012] According to the motor of this aspect, even when there is a difference in the flow rate of the resin material at positions other than the connection portion between the first main body portion and the first outer wall portion, the balance of the flow rate of the resin material during insert molding can be appropriately set.

[0013] (5) In the electric motor of the above aspect, the stator core may include the tooth protrusion. The thickness of the electrical insulator defined from the surface of the tooth protrusion to the surface of the protrusion of the electrical insulator may be the same as the thickness of the electrical insulator defined from the first side surface of the tooth to the surface of the first main body of the electrical insulator.

[0014] According to the electric motor of this aspect, by making the thickness of the electrical insulator uniform, it is possible to suppress or prevent local variations in the insulation performance of the stator core.

[0015] (6) In the electric motor of the above embodiment, the electrical insulator may further include a second outer wall portion disposed on the second axial side of the yoke, a second main body portion disposed on the second axial side of the tooth base portion, and a second inner wall portion disposed on the second axial side of the tooth tip portion. Alternatively, the electrical insulator may include: a first electrical insulating portion including the first outer wall portion, the first main body portion, and the first inner wall portion; a second electrical insulating portion including the second outer wall portion, the second main body portion, and the second inner wall portion; and an insulator connecting portion provided to connect the first and second electrical insulating portions.

[0016] The electric motor of this embodiment can reduce the number of steps for assembling the electrical insulator and the stator core, thereby improving the productivity of the electric motor. In addition, by providing the insulator connection portion in the middle of the axial direction, the electric motor can be manufactured without remaking the forming mold even if the stacking thickness (axial length) of the stator is changed.

[0017] (7) According to another embodiment of the present disclosure, a compressor is provided that includes a compression mechanism for compressing and delivering a fluid and an electric motor for driving the compression mechanism. Alternatively, the compressor may include the electric motor according to the above-described embodiments.

[0018] The present disclosure can also be implemented in various forms other than electric motors, for example, in forms such as a stator, a method for manufacturing a stator, a method for manufacturing an electric motor, and a method for forming a stator winding. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is an explanatory diagram showing the internal structure of a compressor including the motor according to the first embodiment.

[0020] Figure 2 It is an explanatory diagram showing the structure of a stator used in the motor according to the first embodiment.

[0021] Figure 3 Yes Figure 2 Cross-sectional view of the III-III position.

[0022] Figure 4 It is a perspective view showing the external structure of an electrical insulator.

[0023] Figure 5 It is a plan view showing the external structure of an electrical insulator.

[0024] Figure 6 It is an enlarged representation Figure 5 Illustration of the local range.

[0025] Figure 7 It is an explanatory diagram schematically showing a stator winding wound around the main body.

[0026] Figure 8 It is an explanatory diagram showing the structure of the outer wall portion.

[0027] Figure 9 It is an explanatory diagram showing an enlarged groove portion.

[0028] Figure 10 It is an explanatory diagram showing an enlarged view of the periphery of the protruding portion.

[0029] Figure 11 It is an explanatory diagram showing the periphery of the first flange portion and the second flange portion in an enlarged manner.

[0030] Figure 12 It is an enlarged representation Figure 3 Illustration of the local range.

[0031] Figure 13 It is an explanatory diagram showing the structure of a conventional stator core as a comparative example.

[0032] Figure 14 It is an explanatory diagram showing the structure of a stator core included in a motor according to a second embodiment.

[0033] Figure 15It is an explanatory diagram showing the structure of a stator core included in a motor according to a third embodiment.

[0034] Figure 16 It is an explanatory diagram showing the structure of a stator core included in a motor according to a fourth embodiment.

[0035] Description of Reference Numerals

[0036] 70, 70R, electrical insulator; 72, outer wall; 74, main body; 76, inner wall; 78, slot; 80, 80R, 80b, 80c, 80d, stator core; 82, yoke; 84, tooth; 86, 86c, 86d1, 86d2, notch; 86P1, first portion; 86P2, second portion; 88, 88c, tooth protrusion; 88s, tooth inclined wall; 90, 90A, 90B, 90S, 90T, stator winding; 100, stator; 200, rotor; 300, compressor; 301, housing; 302, suction port; 303, motor chamber; 304, communication path; 305, discharge port; 310, motor; 320, compression mechanism; 322, fixed scroll; 324, movable scroll; 330, Drive shaft; 332, eccentric pin; 340, drive circuit; 701, first electrical insulating portion; 702, second electrical insulating portion; 703, insulator connecting portion; 720, inner circumference; 722T, upper end; 724, groove; 741, first side surface; 742, second side surface; 743, connecting portion; 744, protrusion; 744s, inclined wall; 746, first end surface; 746E, protrusion; 746R, recess; 761, first flange portion; 762, second flange portion; 780, slot opening; 820, yoke inner circumference; 841, first side surface of tooth; 842, second side surface of tooth; 844, tooth top portion; 844T, tooth top surface; 846, tooth base; 862, bent portion; 863, connecting portion; AX, rotation axis; SP, gap. DETAILED DESCRIPTION

[0037] A. First embodiment:

[0038] A1. Structure of compressor 300 and motor 310:

[0039] Figure 1 This is an explanatory diagram showing the internal structure of a compressor 300 equipped with a motor 310 according to the first embodiment of the present disclosure. Compressor 300 is, for example, a scroll-type electric compressor. Compressor 300 is mounted on, for example, a vehicle (not shown), and functions as a refrigerant circuit of a vehicle air conditioner, for example, together with an evaporator, an expansion valve, and a condenser.

[0040] like Figure 1As shown, compressor 300 includes housing 301, motor 310, compression mechanism 320 for compressing and delivering fluid, drive shaft 330, and drive circuit 340. Housing 301 houses motor 310 and compression mechanism 320. Housing 301 is formed with suction port 302, motor chamber 303 in which motor 310 is disposed, and discharge port 305.

[0041] The suction port 302 communicates with the motor chamber 303. The suction port 302 is connected to, for example, an evaporator (not shown), receives refrigerant supplied from the evaporator, and flows the refrigerant into the motor chamber 303. The discharge port 305 discharges the high-pressure refrigerant compressed by the compression mechanism 320 to the outside of the compressor 300. The discharge port 305 is connected to, for example, a condenser (not shown).

[0042] The drive shaft 330 is a generally cylindrical member extending along the rotation axis AX. The drive shaft 330 is supported within the housing 301 so as to be rotatable about the rotation axis AX. A generally cylindrical eccentric pin 332 is formed at the end of the drive shaft 330. The eccentric pin 332 is positioned at a predetermined distance from the rotation axis AX.

[0043] The motor 310 generates a driving force that rotates the drive shaft 330 around the rotation axis AX. The motor 310 is an example of an "electric motor". The motor 310 includes a rotor 200 and a stator 100 having a substantially cylindrical shape. The stator 100 is fixed in the motor chamber 303. The stator 100 is electrically connected to the drive circuit 340. The drive circuit 340 is, for example, an inverter configured to control the motor 310. The rotor 200 is configured inside the stator 100 so as to be rotatable relative to the stator 100. The rotor 200 is connected to the drive shaft 330. The rotation of the rotor 200 causes the drive shaft 330 to rotate around the rotation axis AX.

[0044] The compression mechanism 320 includes a fixed scroll 322 and a movable scroll 324. The movable scroll 324 is connected to the drive shaft 330 via an eccentric pin 332. The fixed scroll 322 is fixed to the housing 301. A communication path 304 is formed in the fixed scroll 322. The fixed scroll 322 and the movable scroll 324 each have a wall surface configured in a spiral shape, and the spiral wall surfaces are configured in a manner that meshes with each other. As a result, a compression chamber capable of compressing refrigerant is formed between the fixed scroll 322 and the movable scroll 324. When the motor 310 is operating and the drive shaft 330 rotates around the rotation axis AX, the movable scroll 324 rotates, and the refrigerant in the compression chamber is compressed. The compressed refrigerant is sent from the compression mechanism 320 to the discharge port 305 via the communication path 304.

[0045] A2. Structure of stator 100:

[0046] Figure 21 is an explanatory diagram showing the structure of the stator 100 included in the motor 310 according to the first embodiment. Figure 2 As shown, the stator 100 includes a stator core 80 , an electrical insulator 70 , and a stator winding 90 . Figure 2 The three directions used in the present disclosure are schematically shown. "Axial direction Z" refers to the axial direction of the rotation axis AX of the rotor 200. The side of the first outer wall portion 72 described later in the axial direction Z is defined as the "axial first side Z1", and the opposite side is defined as the "axial second side Z2". When the motor 310 is arranged along the vertical direction, the axial first side Z1 is sometimes referred to as the "upper side", and the axial second side Z2 is sometimes referred to as the "lower side". "Circumferential direction X" refers to the circumferential direction centered on the rotation axis AX. In the circumferential direction X, when observing the motor 310 from the axial first side Z1, the counterclockwise direction is defined as the "circumferential first side X1", and the clockwise direction is defined as the "circumferential second side X2". "Radial direction Y" is a direction passing through the rotation axis AX and orthogonal to the rotation axis AX. Radial direction Y refers to the radial direction centered on the rotation axis AX. In the radial direction Y, the rotation axis AX side is defined as the "radial inner side Y2", and the opposite side is defined as the "radial outer side Y1".

[0047] Figure 3 Yes Figure 2 The cross-sectional view of the III-III position. Figure 3 In order to facilitate understanding of the technology, the stator winding 90 is omitted. The stator core 80 is formed by stacking a plurality of electromagnetic steel sheets. Figure 3 As shown, the stator core 80 includes a yoke 82 and a plurality of teeth 84 extending along the circumferential direction X. In order to electrically insulate the stator winding 90 from the stator core 80 , the electrical insulator 70 is configured to cover the stator core 80 .

[0048] The teeth 84 extend from the yoke 82 in a direction approaching the rotation axis AX, that is, in the radial direction inward Y2. The plurality of teeth 84 are arranged so as to be spaced apart from each other along the circumferential direction X. The slots 78 are defined by the teeth 84 adjacent in the circumferential direction. The number of teeth 84 is appropriately set.

[0049] Each tooth 84 includes a tooth base 846 and a tooth tip 844. The tooth base 846 is connected to the yoke inner circumferential surface 820 of the yoke 82. The tooth base 846 extends from the yoke inner circumferential surface 820 of the yoke 82 toward the radially inner side Y2. The portion where the tooth base 846 connects to the yoke 82 is also referred to as a "connecting portion 863." The tooth base 846 includes a first tooth side surface 841 on the first circumferential side X1 and a second tooth side surface 842 on the second circumferential side X2.

[0050] The tooth tip portion 844 is a portion connected to the tip of the radial inner side Y2 of the tooth base portion 846. Figure 3As shown, the tooth tip portion 844 extends toward the first circumferential side X1 and the second circumferential side X2 from the tip of the tooth base portion 846. The tooth tip surface 844T formed on the radially inner side Y2 of the tooth tip portion 844 defines a space inside the stator core in which the rotor 200 is rotatably arranged.

[0051] like Figure 3 As shown, the slot 78 is a space defined by two teeth 84 adjacent in the circumferential direction X and the inner circumferential surface 820 of the yoke of the stator core 80. The slot opening 780 is defined by the tooth tip 844 of the tooth 84 located on the first circumferential side X1 and the tooth tip 844 of the tooth 84 located on the second circumferential side X2. In the concentrated winding method, the stator winding 90 is wound around the main body 74 by inserting a needle into the slot 78 from the inside of the electrical insulator 70 through the slot opening 780 and moving the inserted needle.

[0052] A3. Structure of the electrical insulator 70:

[0053] Reference Figures 4 to 6 , the structure of the electrical insulator 70 will be described. Figure 4 It is a perspective view showing the external appearance structure of the electrical insulator 70 . Figure 5 70 is a top view showing the appearance of the electrical insulator 70. The electrical insulator 70 is formed of a resin having insulating properties. The electrical insulator 70 is sometimes also referred to as a "resin frame". Figure 4 As shown, the electrical insulator 70 includes a first electrical insulating portion 701 disposed on the first axial side Z1 of the stator core 80, a second electrical insulating portion 702 disposed on the second axial side Z2 of the stator core 80, and an insulator connecting portion 703. Furthermore, the electrical insulator 70 is not limited to resin and may be formed of materials other than resin.

[0054] The insulator connecting portion 703 is connected between the first electrical insulating portion 701 and the second electrical insulating portion 702. Figure 3 and Figure 4 As shown, the insulator connection portion 703 is formed on the inner surface side of the stator core 80. Specifically, the insulator connection portion 703 is formed on the yoke inner peripheral surface 820, the tooth first side surface 841, and the tooth second side surface 842.

[0055] In this embodiment, the electrical insulator 70 is formed by insert molding. Specifically, a resin material is introduced into a mold with the stator core 80 disposed therein, and the resin material is cured. As a result, the electrical insulator 70 is formed with the stator core 80 housed therein, and the first electrical insulating portion 701, the second electrical insulating portion 702, and the insulator connecting portion 703 are integrated.

[0056] The first electrical insulating portion 701 includes a first outer wall portion 72 disposed on the first axial side Z1 of the yoke 82, a first main body portion 74 disposed on the first axial side Z1 of the tooth base portion 846, and a first inner wall portion 76 disposed on the first axial side Z1 of the tooth tip portion 844. The second electrical insulating portion 702 includes a second outer wall portion disposed on the second axial side Z2 of the yoke 82, a second main body portion disposed on the second axial side Z2 of the tooth base portion 846, and a second inner wall portion disposed on the second axial side Z2 of the tooth tip portion 844. The second outer wall portion, second main body portion, and second inner wall portion are formed on the second axial side Z2 at positions corresponding to the first outer wall portion 72, first main body portion 74, and first inner wall portion 76, respectively. The structures of the second outer wall portion, second main body portion, and second inner wall portion are identical to those of the first outer wall portion 72, first main body portion 74, and first inner wall portion 76, and therefore their description will be omitted. The insulator connecting portion 703 includes a third outer wall portion arranged on the radially inner side Y2 of the yoke inner circumferential surface 820 of the yoke 82, a third main body portion arranged on the circumferential first side X1 of the tooth base 846, a fourth main body portion arranged on the circumferential second side X2 of the tooth base 846, a third inner wall portion arranged on the circumferential first side X1 of the tooth tip 844, and a fourth inner wall portion arranged on the circumferential second side X2 of the tooth tip 844. In this specification, the first outer wall portion 72, the second outer wall portion, and the third outer wall portion are simply referred to as the "outer wall portion 72" when not being distinguished. The first main body portion 74, the second main body portion, the third main body portion, and the fourth main body portion are simply referred to as the "main body portion 74" when not being distinguished. The first inner wall portion 76, the second inner wall portion, the third inner wall portion, and the fourth inner wall portion are simply referred to as the "inner wall portion 76" when not being distinguished.

[0057] like Figure 4 As shown, the outer wall portion 72 is a portion extending axially toward the first side Z1 relative to the main body portion 74. Conductive wires connecting the stator windings 90 wound around the main body portion 74 are arranged on the outer wall portion 72. The outer wall portion 72 is formed with grooves 724 described below.

[0058] The main body 74 is a portion for winding the stator winding 90. The portion connecting the main body 74 and the outer wall 72 is also referred to as the "connecting portion 743". Figure 5 As shown, the main body portion 74 includes a first side surface 741 on the first circumferential side X1 and a second side surface 742 on the second circumferential side X2. The first side surface 741 is disposed on the first circumferential side X1 of the tooth first side surface 841 of the stator core 80, and the second side surface 742 is disposed on the second circumferential side X2 of the tooth second side surface 842. Furthermore, the first side surface 741 is included in the third main body portion, and the second side surface 742 is included in the fourth main body portion.

[0059] Figure 6 It is an enlarged representation Figure 5FIG. 7 is an explanatory diagram of a local range AR2. In the electrical insulator 70, a protrusion 744 is formed in the connection portion 743 connecting the main body 74 and the outer wall 72 on the first side surface 741 side. The protrusion 744 is configured to protrude from the inner peripheral surface 720 toward the radial inner side Y2 and from the first side surface 741 toward the circumferential first side X1. The protrusion 744 is formed over the entire length of the main body 74 in the axial direction Z (see FIG. 7 ). Figure 4 ). In other words, in this embodiment, the electrical insulator 70 includes: a protrusion 744 formed at the connection portion 743 between the first main body 74 and the first outer wall 72 in the first electrical insulating portion 701; a second protrusion having a second inclined wall surface formed at the connection portion 743 between the second main body and the second outer wall in the second electrical insulating portion 702; and a third protrusion having a third inclined wall surface formed at the connection portion 743 between the third main body and the third outer wall in the insulator connection portion 703. By providing the inclined wall surfaces on both sides of the axial first side Z1 and the axial second side Z2 and between them, the stator winding 90 is easily arranged along the axial direction Z. Therefore, it is possible to more reliably suppress or prevent the arrangement of the stator winding 90 from being disturbed. However, the protrusion 744 is not limited to being formed along the entire length of the connection portion 743 of the main body 74, and may also be formed at a portion of the connection portion 743. For example, the protrusion 744 may be formed only on the connection portion 743 between the first main body portion 74 and the first outer wall portion 72. At least one of the second protrusion and the third protrusion may be omitted. In addition, a plurality of protrusions 744 may be provided on one connection portion 743.

[0060] The protrusion 744 includes an inclined wall surface 744s connected to the inner circumferential surface 720 of the outer wall portion 72 and the first side surface 741. When the stator winding 90 is wound on the first side surface 741, the stator winding 90 in contact with the protrusion 744 is guided along the inclined wall surface 744s to a suitable arrangement position. Furthermore, the protrusion 744 restricts movement of the stator winding 90 toward the radially outward side Y1. The protrusion 744 suppresses or prevents the stator windings 90 arranged around the main body 74 from being wound in a manner that intersects with each other.

[0061] When the surface of the main body 74 on the first axial side Z1 is defined as the first end face 746, a plurality of protrusions 746E are formed on the first end face 746. The plurality of protrusions 746E are arranged along the extension direction of the main body 74. The protrusions 746E protrude from the first end face 746 toward the first axial side Z1. More specifically, the protrusions 746E have a generally triangular pyramidal appearance, with the top of the protrusion 746E protruding from the first end face 746 toward the first axial side Z1. The recesses 746R are defined by adjacent protrusions 746E. The recesses 746R restrict movement of the stator winding 90 arranged on the first end face 746 in the radial direction Y. The recesses 746R are arranged at equal intervals. As a result, the stator windings 90 arranged on the first end face 746 are easily arranged parallel to each other, and the stator windings 90 can be suppressed or prevented from being wound crosswise around the main body 74.

[0062] like Figure 6 As shown, the inner wall portion 76 includes a first flange portion 761 that protrudes from the main body portion 74 toward the first circumferential side X1, and a second flange portion 762 that protrudes from the main body portion 74 toward the second circumferential side X2. The first flange portion 761 and the second flange portion 762 prevent the stator winding 90 wound around the main body portion 74 from falling out toward the radially inward side Y2. In this embodiment, as described later, the thickness of the second flange portion 762 in the radial direction Y is configured to be greater than the thickness of the first flange portion 761 in the radial direction Y.

[0063] A4. Structure of stator winding 90:

[0064] Figure 7 : is an explanatory diagram schematically showing the stator winding 90 wound around the main body 74. Figure 7 Schematically shows the distance L1 in the radial direction Y from the wall surface of the radially outer side Y1 of the first flange portion 761 to the inner peripheral surface 720, and the distance L2 in the radial direction Y from the wall surface of the radially outer side Y1 of the second flange portion 762 to the inner peripheral surface 720. Figure 7 Schematically shows the thickness T1 of the first flange portion 761 in the radial direction Y and the thickness T2 of the second flange portion 762 in the radial direction Y. Figure 7 In order to facilitate understanding of the technology, the structure of each part is simplified. In this specification, for the sake of convenience, the conductive wire forming the stator winding 90 is sometimes simply referred to as "stator winding 90".

[0065] The method of forming the stator winding 90 will be described. Figure 4 As shown, the stator winding 90 is guided from the outer wall portion 72 to the main body portion 74 through the groove portion 724. The stator winding 90 guided to the main body portion 74 is repeatedly wound around the main body portion 74 and arranged in sequence along the radial direction Y. Figure 7The numbers in the stator winding 90 shown schematically represent the order in which the stator winding 90 is wound. The numbers in the stator winding 90 are indicated on the first side 741 and the second side 742. In this embodiment, the winding order is from the second side 742 to the first side 741.

[0066] like Figure 7 As shown by the number "1" on the right side of the stator winding 90, the stator winding 90 is guided from the outer wall portion 72 to the vicinity of the connection portion 743 between the second side surface 742 and the inner peripheral surface 720. In this specification, the unit of arrangement of the stator winding 90 along the radial direction Y is defined as a "row", and the unit of arrangement along the circumferential direction X is defined as a "level". Figure 7 In the example, the outermost side in the radial direction Y of the first stage ST1 is the position of the stator winding 90 of the first column CL1 wound for the first time.

[0067] After the stator winding 90 passes on the second side surface 742 along the axial direction Z, as shown in FIG. Figure 7 As shown by the arrow A1, the main body 74 passes through the second end surface side opposite to the first end surface 746 of the main body 74 from the second side X2 in the circumferential direction toward the first side X1 in the circumferential direction. Figure 7 As shown by the number "1" on the left side of the stator winding 90, which has passed through the second end surface, is guided to the first side surface 741 and passes through the first side surface 741 along the axial direction Z. Figure 7 As indicated by the middle arrow A2, the stator winding 90 passing on the first side surface 741 is guided from the circumferential first side X1 toward the circumferential second side X2 on the first end surface 746. In this way, the stator winding 90 completes one round of winding around the main body 74.

[0068] When the stator winding 90 is guided to the second side surface 742 again, the winding is repeated in the same manner. Figure 7 As shown by the number "2" on the right side of the , the columns after the second column CL2 are adjacent to the first column CL1 toward the radial inner side Y2 and are arranged in sequence. Figure 7 As shown by the number "n+1" on the right side of the , when the stator winding 90 of the first stage ST1 reaches the inner wall portion 76, the arrangement of the stator winding 90 of the first stage ST1 is completed. Figure 7 As indicated by the number "n+2" on the right side of the stator winding 90, the stator winding 90 is stacked on the second circumferential side X2 relative to the first stage ST1. Furthermore, on the first side surface 741, the stator winding 90 is stacked on the first circumferential side X1 relative to the first stage ST1. The stator winding 90 is arranged radially outward Y1, starting with the second stage ST2, and the same pattern is repeated for the third and subsequent stages ST3.

[0069] use Figure 8 and Figure 9, the structure of the groove portion 724 provided on the inner peripheral surface 720 of the outer wall portion 72 will be described. Figure 8 72 is an explanatory diagram showing the structure of the outer wall portion 72. Figure 8 As shown, the groove 724 is provided in the inner circumferential surface 720 of the outer wall portion 72 at a position intersecting the plane direction SD of the second side surface 742, and in the vicinity thereof. Specifically, the groove 724 is formed in the vicinity of an extension of the second side surface 742. Furthermore, the groove 724 extends in the axial direction Z from the vicinity of the first end surface 746 of the main body portion 74 in the inner circumferential surface 720 to the upper end 722T of the outer wall portion 72. In other words, the groove 724 is provided on the introduction path of the stator winding 90 from the outer wall portion 72 to the main body portion 74.

[0070] Figure 9 724 is an enlarged view of the groove portion 724. Figure 9 As shown, in this embodiment, the depth of the groove 724 is configured to be substantially consistent with the diameter of the conductive wire forming the stator winding 90. Therefore, the surface of the stator winding 90 passing through the groove 724 is substantially flush with the inner peripheral surface 720. That is, by providing the groove 724 on the inner peripheral surface 720, the stator winding 90 can be offset radially outward Y1 by an amount corresponding to the depth of the groove 724 in the introduction path of the stator winding 90 from the outer wall portion 72 to the second side surface 742. Therefore, for example, it is possible to suppress or prevent the stator winding 90 from being displaced radially outward Y1. Figure 9 The portion of the stator winding 90S guided from the outer wall portion 72 toward the second side surface 742, as shown at position P1, interferes with the portion of the stator winding 90T constituting the second stage ST2 or subsequent stages, as shown at position P2. The depth of the groove 724 is not limited to being substantially equal to the diameter of the conductor; it may also be greater than the diameter of the conductor. Furthermore, the depth of the groove 724 may be smaller than the diameter of the stator winding 90. Furthermore, the groove 724 may be omitted.

[0071] Figure 10 744 is an enlarged explanatory diagram showing the periphery of the protrusion 744. Figure 10 As shown, it is believed that if the stator windings 90 can be arranged in a densest structure with substantially the smallest gaps between the stator windings 90, the slot fill factor of the stator windings 90 can be improved. When the inner peripheral surface of the protrusion 744 is formed as an inclined wall surface 744s, the stator winding 90 located most outside in the radial direction Y can contact the inclined wall surface 744s.

[0072] In the present embodiment, the inclined wall surface 744s is a plane that is inclined in a manner that it goes from the radially outer side Y1 toward the radially inner side Y2 as it goes from the circumferential first side X1 toward the circumferential second side X2. By configuring in this manner, in the first stage ST1, the second stage ST2, and the third stage ST3, the arrangement of the stator winding 90 arranged at the outermost side in the radial direction Y can be restricted along the surface direction of the inclined wall surface 744s. In addition, in the present embodiment, the inclination angle θ1 between the surface direction of the inclined wall surface 744s and the extension direction of the main body 74 (radial direction in the present embodiment) is configured to be approximately 55 degrees. By configuring in this manner, the stator winding 90 can be arranged in the densest structure, thereby improving the slot filling rate of the stator winding 90. In addition, in the present embodiment, compared with the case where the inclination angle θ1 is set to 60 degrees, the error after taking into account the diameter deviation of the stator winding 90 and the deviation of the configuration position of the stator winding 90 is set to 5 degrees. This prevents a decrease in the number of stator windings 90 arranged per stage due to variations in the diameter of the stator windings 90 or in the arrangement positions of the stator windings 90. However, the inclined wall surface 744s is not limited to a flat surface and may also be a curved surface. In this case, the inclined wall surface 744s may be a curved surface that is convex toward the radially inner side, i.e., the slot 78 side, or a curved surface that is concave toward the radially outer side, i.e., the side opposite the slot 78.

[0073] However, the tilt angle θ1 is not limited to 55 degrees. The tilt angle θ1 can be set to 60 degrees, for example. In addition, the tilt angle θ1 is preferably greater than 40 degrees. When the tilt angle θ1 is less than 40 degrees, for example, the outermost stator winding 90 arranged in the radial direction Y of the second stage ST2 is likely to fall off toward the first stage ST1, and the slot fill rate may decrease. In addition, the tilt angle θ1 is preferably less than 70 degrees. When the tilt angle θ1 is greater than 70 degrees, the space in which the stator winding 90 can be arranged in the radial direction Y becomes smaller, the number of stator windings 90 arranged in each stage is reduced, and the slot fill rate may decrease.

[0074] Figure 10 The cross-sectional width WS of the inclined wall surface 744s is shown. The cross-sectional width WS of the inclined wall surface 744s referred to herein refers to the width from the inner circumferential surface 720 of the outer wall portion 72 to the first side surface 741. In this embodiment, the cross-sectional width WS is configured to be approximately 2.2 times the diameter DM of the conductive wire forming the stator winding 90. This configuration allows the outermost stator windings 90 in the radial direction Y to be arranged in the densest configuration in the three stages, from the first stage ST1 to the third stage ST3, thereby improving the slot fill rate of the stator windings 90 across multiple stages.

[0075] However, the cross-sectional width WS is not limited to 2.2 times the diameter DM. The cross-sectional width WS is preferably, for example, 1.5 times or more of the diameter DM. By configuring in this way, at least in the first stage ST1 and the second stage ST2, the outermost stator windings 90 in the radial direction Y can be arranged into the densest structure. In the case where the cross-sectional width WS is less than 1.5 times the diameter DM, there is a possibility that the stator windings 90 of the stages after the second stage ST2 will be difficult to arrange. In addition, the cross-sectional width WS is preferably, for example, 3 times or less of the diameter DM. In the case where the cross-sectional width WS is greater than 3 times the diameter DM, the size of the protrusion 744 is excessive, for example, the number of columns of the stator windings 90 that can be arranged in the first stage ST1 is reduced, and the slot fill rate may be reduced.

[0076] exist Figure 10 shows the thickness WT of the protrusion 744 in the radial direction Y. In this embodiment, the thickness WT is determined by the design of the cross-sectional width WS and the inclination angle θ1. However, the thickness WT can also be set using the distance in the radial direction Y from the protrusion 744 to the first flange portion 761. For example, by setting the thickness WT so that the distance in the radial direction Y from the protrusion 744 to the first flange portion 761 is an integral multiple of the diameter DM, it is possible to suppress or prevent the formation of gaps between the stator windings 90 arranged on the first side surface 741.

[0077] Reference Figure 11 , the structure of the inner wall portion 76 is described. Figure 11 : is an explanatory diagram showing the periphery of the first flange portion 761 and the second flange portion 762 in an enlarged manner. Figure 11 As shown, in this embodiment, the thickness T2 of the second flange portion 762 in the radial direction Y is configured to be thicker than the thickness T1 of the first flange portion 761 in the radial direction Y. More specifically, in the second flange portion 762, the thickness T2 of the portion configured to be radially outward Y1 is thicker than the thickness T1 of the first flange portion 761 by the amount of thickness TU. By making the thickness T2 of the second flange portion 762 thicker, the configuration position of the stator winding 90 arranged on the second side surface 742 can be shifted toward the radially outward Y1 by the amount of the increased thickness TU. In addition, Figure 7 The cumulative value of the distance L1 and the thickness T1 shown is approximately the same as the cumulative value of the distance L2 and the thickness T2. The distance from the inner wall portion 76 to the rotor 200 is approximately uniform from the first flange portion 761 to the second flange portion 762. Furthermore, the distance from the inner circumferential surface 720 to the top end surface of the inner wall portion 76 is approximately constant.

[0078] exist Figure 11, as a comparative example, shows position 90R of the stator winding 90 without increasing the thickness of the second flange portion 762. A gap SP may form between the stator winding 90 arranged at position 90R and the stator winding 90 arranged at the adjacent position 90Q. The formation of gap SP can cause the stator winding 90 of the second stage ST2 to fall out, reducing the slot fill rate. In this embodiment, the formation of gap SP is suppressed or prevented by setting the thickness TU to a thickness equivalent to gap SP. By arranging the stator winding 90 in the densest arrangement even at the innermost position in the radial direction Y, the slot fill rate of the stator winding 90 can be improved.

[0079] Furthermore, the thickness TU can also be used, for example, in Figure 7 The thickness TU is set by dividing the distance L2 in the radial direction Y from the wall surface of the radially outer side Y1 of the second flange portion 762 to the inner peripheral surface 720 by the diameter DM, which is the remainder (also referred to as the "remainder"). In other words, the thickness TU can be determined by a simple method of predicting the size of the gap SP using the calculated remainder.

[0080] The thickness TU can also be set using the diameter DM of the wire forming the stator winding 90. The thickness TU can be set, for example, to 0.5 times the diameter DM of the wire forming the stator winding 90. By configuring in this way, it is possible to suppress or prevent the generation of gaps between the stator windings 90 on the second side 742, the stator winding 90 from falling off to the first stage ST1, and the like. The thickness TU is preferably set, for example, to 0.25 times or more of the diameter DM. In the case where the thickness TU is less than 0.25 times the diameter DM, gaps may be generated between the stator windings 90, causing the arrangement of the stator windings 90 to be disordered. In addition, the thickness TU is preferably set to less than 1.0 times the diameter DM. In the case where the thickness TU is more than 1.0 times the diameter DM, it is possible to reduce the number of stator windings 90 that can be arranged on the second side 742.

[0081] like Figure 11 As shown, the second flange portion 762 extends from the second side surface 742, which is the side surface of the main body 74 opposite the first side surface 741 forming the protrusion 744. In other words, the thickness of the flange portion is increased on the side opposite the protrusion 744 across the main body 74 in the circumferential direction X. By increasing the thickness T2 of the second flange portion 762 on the side opposite the protrusion 744, the relative arrangement position of the stator winding 90 arranged on the second side surface 742 can be offset relative to the arrangement position of the stator winding 90 arranged on the first side surface 741 according to the size of the protrusion 744.

[0082] In this embodiment, the position of the stator winding 90 on the second side surface 742 is relatively offset to the radially outer side Y1 relative to the position of the stator winding 90 on the parallel first side surface 741. Figure 11 In the example shown in FIG. 1 , the position of stator winding 90A in contact with second flange portion 762 on the second side surface 742 is offset radially outward by an angle θ2 relative to the position of stator winding 90B in contact with first flange portion 761 on the first side surface 741. Furthermore, when stator winding 90 on the second side surface 742 is arranged side by side in circumferential direction X relative to stator winding 90 on the first side surface 741, as in arrangement position 90R, angle θ2 is zero.

[0083] In this embodiment, the stator winding 90 is wound at an angle θ2 toward the radially outer side Y1 relative to the parallel arrangement, so that it can be wound while applying a force toward the radially outer side Y1. Therefore, the next stator winding 90 can be wound adjacent to the stator winding 90 wound radially outward Y1, and the arrangement of the stator winding 90 can be suppressed or prevented. In addition, as Figure 6 As shown, the arrangement of the recessed portions 746R on the second side surface 742 side is shifted by an angle θ2 with respect to the arrangement of the recessed portions 746R on the first side surface 741 side.

[0084] A5. Structure of stator core 80:

[0085] Reference Figure 12 and Figure 13 , the structure of the stator core 80 is described. Figure 12 It is an enlarged representation Figure 3 In this embodiment, as shown in FIG. Figure 12 As shown, a notch 86 having a concave shape facing in a direction opposite to the slot 78 is formed in a connection portion 863 connecting the tooth second side surface 842 and the yoke inner peripheral surface 820 in the stator core 80 .

[0086] Figure 13 1 is an explanatory diagram showing the structure of a conventional stator core 80R as a comparative example. Figure 13As shown, the conventional electrical insulator 70R does not include the protrusion 744, and the stator core 80R does not include the notch 86. In the conventional stator core 80R, the cross-sectional area of the connection portion 743 on the first side 741 side is substantially the same as the cross-sectional area of the connection portion 743 on the second side 742 side. Therefore, when the stator core 80R is used to form the electrical insulator 70R, the flow rate of the resin material at the connection portion 743 on the first side 741 side is substantially the same as the flow rate of the resin material at the connection portion 743 on the second side 742 side. For example, when the electrical insulator 70 is formed by insert molding, when the resin material is introduced between the stator core 80 and the mold, the resin material tends to flow substantially evenly on both the first side 741 side and the second side 742 side.

[0087] In contrast, in this embodiment, Figure 12 As shown in FIG. 1 , in the electrical insulator 70 , a protrusion 744 is formed on the connection portion 743 on the first side surface 741 side. Figure 12 The cross-hatched area S1 is the cross-sectional area of the protrusion 744. The area S1 is considered to be the area of the portion increased by the formation of the protrusion 744 compared to the conventional electrical insulator 70R.

[0088] For example, without forming Figure 12 If only the protrusion 744 is formed instead of the notch 86 shown, the volume of the space between the mold and the stator core 80 increases by an amount corresponding to the area S1. Therefore, when insert molding is used to form the electrical insulator 70, resin tends to flow into the protrusion 744. As a result, the flow rate of the resin material on the first side 741 side may be greater than the flow rate of the resin material on the second side 742 side. In this case, the resin material may not be fully filled between the connection portion 743 on the second side 742 side and the mold, potentially resulting in a molding defect such as a so-called short shot.

[0089] In this embodiment, a notch 86 is formed on the tooth's second side surface 842, opposite the tooth's first side surface 841 where the protrusion 744 is formed. The notch 86 increases the volume from the stator core 80 to the mold, thereby increasing the flow rate of the resin material introduced during insert molding. In this embodiment, the notch 86 formed on the second side surface 742 ensures that the flow rate of the resin material in the connecting portion 743 on the first side surface 741 and the flow rate of the resin material in the connecting portion 743 on the second side surface 742 are substantially equal.

[0090] like Figure 12As shown, the notch 86 includes a first portion 86P1 formed on the yoke inner circumferential surface 820 of the yoke 82 and having a concave shape extending radially outward from the yoke inner circumferential surface 820 toward the first circumferential side X1; and a second portion 86P2 having a concave shape extending circumferentially from the tooth second side surface 842 toward the first circumferential side X1. The inclusion of both the first portion 86P1 and the second portion 86P2 increases the area of the notch 86, thereby increasing the flow rate of the resin material at the notch 86. Furthermore, in this embodiment, the first portion 86P1 and the second portion 86P2 have a connected, integral concave shape. Forming the notch 86 over a wide range from the yoke inner circumferential surface 820 to the tooth second side surface 842 increases the flow rate of the resin material at the connecting portion 863 compared to a case where the notch 86 is provided separately on the yoke inner circumferential surface 820 and the tooth second side surface 842.

[0091] like Figure 12 As shown, the plane shape of the notch 86 is formed using a curve. For example, the first portion 86P1 and the second portion 86P2 are connected by a curved portion 862 with a smaller curvature. The curvature of the curved portion 862 is, for example, smaller than Figure 12 The curvature of the connecting portion 863 between the yoke inner circumferential surface 820 and the tooth first side surface 841 shown on the left side of the figure is small. This configuration reduces the flow resistance of the notch 86 and increases the flow rate of the resin material in the notch 86 during insert molding. Consequently, the notch 86 can be made smaller than in a case without the curved portion 862.

[0092] Furthermore, in this embodiment, the cross-sectional area S1 of the protrusion 744 is configured to be different from the cross-sectional area S2 of the notch 86. Specifically, the cross-sectional area S2 is configured to be smaller than the cross-sectional area S1. This is because the difference in the flow rate of the resin material between the first side surface 741 and the second side surface 742, which occurs when the thickness T2 of the second flange portion 762 is configured to be greater than the thickness T1 of the first flange portion 761, is taken into account.

[0093] As described above, according to the motor 310 of this embodiment, the electrical insulator 70 includes a protrusion 744 at the connection portion 743 between the main body 74 and the outer wall 72, which is connected to the inner circumferential surface 720 of the outer wall 72 and the first side surface 741. When the stator winding 90 is wound onto the first side surface 741, it can be guided along the protrusion 744 to the appropriate arrangement position. Furthermore, the protrusion 744 restricts movement of the stator winding 90 toward the radially outward side Y1. Consequently, it is possible to suppress or prevent the stator winding 90 from being disorganized on the first side surface 741, thereby improving the slot fill factor of the stator winding 90.

[0094] According to the motor 310 of this embodiment, the angle θ1 between the surface direction of the inclined wall surface 744s and the extension direction of the main body 74 is approximately 55 degrees. This configuration allows the stator windings 90 to be densely arranged to achieve the densest structure, thereby improving the slot fill factor of the stator windings 90.

[0095] In the motor 310 of this embodiment, the cross-sectional width WS of the protrusion 744 from the inner circumferential surface 720 to the first side surface 741 is configured to be approximately 2.2 times the diameter DM of the conductive wire forming the stator winding 90. This configuration allows the outermost stator windings 90 in the radial direction Y to be arranged densely in the three stages, from the first stage ST1 to the third stage ST3, to achieve the closest possible density. Consequently, the slot fill factor of the stator windings 90 across multiple stages can be increased.

[0096] According to the motor 310 of this embodiment, the thickness T2 of the second flange portion 762 along the radial direction Y is configured to be thicker than the thickness T1 of the first flange portion 761 along the radial direction Y. Therefore, the formation of gaps SP between the stator windings 90 on the second side surface 742 can be suppressed or prevented, and the slot fill rate of the stator windings 90 can be improved.

[0097] According to the motor 310 of this embodiment, the position of the stator winding 90A, which contacts the second flange portion 762 on the second side surface 742, is offset radially outward Y1 by an angle θ2 relative to the position of the stator winding 90B, which contacts the first flange portion 761 on the first side surface 741. By winding the stator winding 90 at an angle θ2 tilted radially outward Y1 relative to the parallel arrangement, the stator winding 90 can be wound while applying a force in the radially outward Y1 direction. Therefore, the next stator winding 90 can be wound adjacent to the already wound stator winding 90 radially outward Y1, thereby suppressing or preventing the arrangement of the stator windings 90 from being disturbed.

[0098] The motor 310 of this embodiment includes a groove portion 724 extending in the axial direction at a position on the inner peripheral surface 720 intersecting the surface direction SD of the second side surface 742. Therefore, it is possible to suppress or prevent the stator winding 90S guided from the outer wall portion 72 toward the second side surface 742 from interfering with the stator winding 90T constituting the second stage ST2 or subsequent stages.

[0099] In motor 310 of this embodiment, first insulating portion 701, second insulating portion 702, and insulator connecting portion 703 of insulator 70 are integrally formed by insert molding. This reduces the number of steps required to assemble insulator 70 and stator core 80, improving productivity of motor 310.

[0100] According to the motor 310 of this embodiment, the stator core 80 includes a concave notch 86 formed in the tooth second side face 842 and the yoke inner circumferential surface 820 of the yoke 82 adjacent to the tooth second side face 842. Therefore, when the electrical insulator 70 is formed by insert molding, the flow rate of the resin material at the connection portion 743 on the second side face 742 side can be increased. Therefore, for example, even when the flow rate of the resin material at the connection portion 743 on the first side face 741 side is increased to form the protrusion 744, the flow rate balance of the resin material between the first side face 741 and the second side face 742 can be appropriately set. Consequently, molding defects such as short shots during the formation of the electrical insulator 70 can be reduced or prevented.

[0101] According to motor 310 of this embodiment, notch 86 has a concave shape integrally formed at connection portion 863 between tooth base 846 and yoke 82, comprising a first portion 86P1 formed on yoke inner circumferential surface 820 of yoke 82 and a second portion 86P2 formed on tooth second side surface 842. By widening notch 86 from yoke inner circumferential surface 820 to tooth second side surface 842, the flow rate of resin material in notch 86 during insert molding can be increased compared to a case where notch 86 is provided separately on yoke inner circumferential surface 820 and tooth second side surface 842.

[0102] In motor 310 of this embodiment, notch 86 includes curved portion 862 having a curvature smaller than that of connecting portion 863 between yoke inner circumferential surface 820 of yoke 82 and tooth first side surface 841. This reduces flow resistance in notch 86 and improves the flow rate of resin material in notch 86 during insert molding.

[0103] According to the motor 310 of this embodiment, the cross-sectional area S1 of the protrusion 744 is different from the cross-sectional area S2 of the notch 86. Even if a difference in the flow rate of the resin material occurs at locations other than the connection portion 863 due to, for example, a difference in thickness between the second flange portion 762 and the first flange portion 761, the balance of the flow rate of the resin material during insert molding can be appropriately set.

[0104] B. Second embodiment:

[0105] Figure 14 This diagram illustrates the structure of a stator core 80b included in a motor 310 according to the second embodiment. Stator core 80b differs from stator core 80 shown in the first embodiment in that it includes tooth protrusions 88 in place of notches 86; otherwise, the structure is identical. When insert molding is used to form the electrical insulator 70 having protrusions 744, tooth protrusions 88 suppress or prevent an increase in the flow rate of resin material flowing through the connection portion 743 on the first side surface 741.

[0106] The tooth protrusion 88 is connected to the yoke inner circumferential surface 820 and the tooth first side surface 841 of the yoke 82 at the connection portion 863 between the tooth base 846 and the yoke 82. The tooth protrusion 88 has a shape that protrudes toward the slot 78. In this embodiment, the shape of the tooth protrusion 88 is substantially the same as the cross-sectional shape of the protrusion 744 shown in the first embodiment. Specifically, the tooth protrusion 88 is configured to protrude radially inward Y2 from the yoke inner circumferential surface 820 and circumferentially protrude from the tooth first side surface 841 toward the first side X1. The tooth protrusion 88 has a tooth inclined wall surface 88s connected to the yoke inner circumferential surface 820 and the tooth first side surface 841. The inclination angle θ3 between the tooth inclined wall surface 88s of the tooth protrusion 88 and the radial direction Y is configured to be approximately 55 degrees, the same as the inclination angle θ1. The formation of the tooth protrusion 88 can suppress the increase in volume between the connection portion 863 and the mold. Therefore, when the protrusion 744 is formed, it is possible to suppress or prevent the flow rate of the resin material from increasing on the first side surface 741 side.

[0107] In this embodiment, the distance TB from the tooth inclined wall surface 88s to the mold is set to be, for example, the same as the distance TA1 from the yoke inner circumferential surface 820 to the mold on the tooth first side surface 841 side, the distance TA2 from the tooth first side surface 841 to the mold, the distance TA4 from the yoke inner circumferential surface 820 to the mold on the tooth second side surface 842 side, and the distance TA3 from the tooth second side surface 842 to the mold. "The same as distance TB" means that a tolerance of plus or minus 10% is permitted with respect to distance TB. This allows, for example, for the flow rate of the resin material during insert molding to be uniform overall. Consequently, while forming the protrusion 744, local variations in the flow rate of the resin material during insert molding can be suppressed or prevented. Furthermore, by making the thickness of the electrical insulator 70 uniform, local variations in the insulation performance of the stator core 80 can be suppressed or prevented.

[0108] C. 3rd embodiment:

[0109] Figure 15 3 is an explanatory diagram showing the structure of the stator core 80c included in the motor 310 according to the third embodiment. Figure 15 As shown, the stator core 80c includes a notch 86c, which is a miniaturized version of the notch 86 shown in the first embodiment, and a tooth protrusion 88c, which is a miniaturized version of the tooth protrusion 88 shown in the second embodiment. Thus, the stator core 80c may include both the notch 86c and the tooth protrusion 88c. Even with this configuration, when the electrical insulator 70 having the protrusion 744 is formed by insert molding, the flow rate of the resin material during insert molding can be appropriately balanced between the first side surface 741 and the second side surface 742.

[0110] D. 4th embodiment:

[0111] Figure 16 1 is an explanatory diagram showing the structure of the stator core 80d included in the motor 310 according to the fourth embodiment. Figure 16 As shown, the stator core 80d includes a plurality of notches 86d1 and 86d2. More specifically, the stator core 80d differs from the stator core 80 shown in the first embodiment in that it does not include the curved portion 862. Instead, the stator core 80d is configured such that a first portion 86P1 formed on the yoke inner circumferential surface 820 of the yoke 82 and a second portion 86P2 formed on the tooth second side surface 842 are separate components. As a result, the first portion 86P1 functions as the notch 86d1, and the second portion 86P2 functions as the notch 86d2. Even with this configuration, when insert molding the electrical insulator 70 having the protrusion 744, the flow rate of the resin material during insert molding can be appropriately balanced between the first side surface 741 and the second side surface 742.

[0112] The present disclosure is not limited to the above-mentioned embodiments and can be implemented in various structures within the scope of its main purpose. For example, in order to solve part or all of the above-mentioned problems, or to achieve part or all of the above-mentioned effects, the technical features in the embodiments corresponding to the technical features in each method described in the invention content column can be appropriately replaced or combined. In addition, if the technical features are not described as essential features in this specification, they can be appropriately deleted.

Claims

1. An electric motor comprising a stator and a rotor, wherein: The stator comprises a stator core, an electrical insulator and a stator winding, The stator core has a cylindrical shape extending in the axial direction. The stator core includes a yoke extending in a circumferential direction and a plurality of teeth extending radially inward from the yoke. The teeth have: a tooth base extending radially inward from the yoke; and The tooth top portion is connected to the radial inner top of the tooth base portion. The tooth base portion includes a first tooth side surface on a first circumferential side and a second tooth side surface on a second circumferential side. The electrical insulator comprises: a first outer wall portion disposed on a first axial side of the yoke; a first main body portion disposed on a first axial side of the tooth base portion; and a first inner wall portion disposed on a first axial side of the tooth tip portion; The first main body portion includes a first side surface on a first circumferential side and a second side surface on a second circumferential side. The stator winding is wound around at least the tooth base portion in a state where the first main body portion is arranged on a first side in the axial direction of the tooth base portion. The electrical insulator includes a protrusion formed at a connection portion between the first main body portion and the first outer wall portion and having an inclined wall surface connected to the inner peripheral surface of the first outer wall portion and the first side surface. The stator core includes at least one of a notch portion and a tooth protrusion portion. The notch is formed on at least one of the second side surface of the tooth and the inner peripheral surface of the yoke and has a concave shape facing the side opposite to the slot defined by the circumferentially adjacent teeth. The tooth protrusion is formed at a connection portion between the first side surface of the tooth and the inner peripheral surface of the yoke, and protrudes toward the slot.

2. The electric motor according to claim 1, wherein The stator core includes the notch portion. The notch is provided at the connection portion between the second side surface of the tooth and the inner peripheral surface of the yoke. The notch portion has a concave shape including a first portion formed on the inner peripheral surface of the yoke and a second portion formed on the second side surface of the tooth.

3. The electric motor according to claim 2, wherein The notch portion has a curved portion having a curvature smaller than a curvature of a connection portion between the inner peripheral surface of the yoke and the first side surface of the tooth.

4. The electric motor according to claim 2, wherein The cross-sectional area of the protrusion and the cross-sectional area of the notch are configured to be different from each other.

5. The electric motor according to claim 1, wherein The stator core includes the tooth protrusion. The thickness of the electrical insulator defined from the surface of the tooth protrusion to the surface of the protrusion of the electrical insulator is the same as the thickness of the electrical insulator defined from the first side surface of the tooth to the surface of the first main body of the electrical insulator.

6. The electric motor according to claim 1, wherein The electrical insulator further includes a second outer wall portion disposed on the second axial side of the yoke, a second main body portion disposed on the second axial side of the tooth base portion, and a second inner wall portion disposed on the second axial side of the tooth tip portion. The electrical insulator includes: a first electrical insulating portion, which includes the first outer wall portion, the first main body portion and the first inner wall portion; a second electrical insulating portion, which includes the second outer wall portion, the second main body portion and the second inner wall portion; and an insulator connecting portion, which is connected and arranged between the first electrical insulating portion and the second electrical insulating portion.

7. A compressor comprising a compression mechanism for compressing and delivering a fluid and an electric motor for driving the compression mechanism, wherein: This compressor includes the electric motor according to any one of claims 1 to 6 as the electric motor.

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