Stator, motor, compressor and refrigeration cycle device

Abstract

The stator includes a stator core having a ring-shaped core back, teeth extending from the core back toward a radial inner side, and slots adjacent to the teeth in a circumferential direction; an insulating portion provided to the teeth; and a winding wound to the teeth with the insulating portion interposed. The teeth have an end surface toward an axial direction of the stator core, a side surface facing the slots, and a step portion formed between the end surface and the side surface. The insulating portion has an insulating member covering the end surface of the teeth, and an insulating film covering the side surface of the teeth and covering a part of the insulating member. When a direction perpendicular to both an extending direction of the teeth and the axial direction is set as a tooth width direction, the step portion has a depth D in the axial direction and a width W in the tooth width direction. A gap is provided in the axial direction between the step portion of the teeth and the insulating member. The insulating film overlaps the insulating member on the slot side. In a plane perpendicular to the extending direction of the teeth, a sum of a shortest distance from a joint at which the insulating film meets a surface of the insulating member facing the step portion to the step portion and an overlapping length L0 of the insulating film overlapping the insulating member is above an insulation distance required for insulation of the stator core and the winding, and the overlapping length L0 is a length by which the insulating film overlaps the insulating member. At least one of 0 < D ≤ 1.25 mm and 0 < W ≤ 1.25 mm is satisfied.

Description

Technical Field

[0001] This disclosure relates to stators, electric motors, compressors, and refrigeration cycle devices. Background Technology

[0002] The stator of the electric motor has a stator core with multiple teeth for winding. Slots for receiving the winding are formed between adjacent teeth of the stator core. To insulate the stator core from the winding, insulating members, which are resin molded bodies, are provided on the axial end faces of the teeth, and an insulating film is provided on the inner surface of the slots.

[0003] For example, Patent Document 1 discloses the following technology: In order to ensure the insulation distance between the stator core and the winding, a stepped portion is provided at the axial end of the tooth, and a space portion is provided in the stepped portion.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2009-89493 (refer to paragraph 0017) Figure 6 , 7 ) Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] However, if the stepped section is enlarged to extend the insulation distance, the magnetic circuit within the teeth becomes narrower. Consequently, iron losses increase, leading to a decrease in motor efficiency.

[0009] This disclosure was made to solve the above-mentioned problems, and its purpose is to ensure the insulation between the stator core and the windings and to suppress the reduction of motor efficiency.

[0010] Methods for solving problems

[0011] The stator disclosed herein comprises: a stator core having an annular core back, teeth extending radially inward from the core back, and slots adjacent to the teeth in the circumferential direction; an insulating portion disposed on the teeth; and a winding wound around the teeth with respect to the insulating portion. The teeth have an end face facing the stator core along an axial direction, a side face facing the slot, and a stepped portion formed between the end face and the side face. The insulating portion comprises: an insulating member covering the end face of the teeth; and an insulating film covering the side face of the teeth and a portion of the insulating member. When the direction perpendicular to both the extension direction and the axial direction of the teeth is defined as the tooth width direction, the stepped portion has a depth D in the axial direction and a width W in the tooth width direction. A gap is provided axially between the stepped portion of the teeth and the insulating member. In a plane perpendicular to the extension direction of the teeth, the sum of the shortest distance from the contact point where the insulating film contacts the step face of the insulating member to the stepped portion and the overlap length L0 is greater than or equal to the insulation distance required for the insulation between the stator core and the winding, where the overlap length L0 is the length by which the insulating film overlaps with the insulating member. At least one of 0 < D ≤ 1.25 mm and 0 < W ≤ 1.25 mm is true.

[0012] Invention Effects

[0013] According to this disclosure, the sum of the shortest distance from the contact point where the insulating member's surface facing the step contacts the insulating film and the step portion, plus the overlap length L0, is greater than or equal to the insulation distance. Furthermore, regarding the depth D and width W of the step portion, at least one of 0 < D ≤ 1.25 mm and 0 < W ≤ 1.25 mm is true. Therefore, it is possible to insulate the stator core from the windings and ensure the magnetic circuit within the teeth, thus suppressing the increase in iron losses and thereby suppressing the decrease in motor efficiency. Attached Figure Description

[0014] Figure 1 This is a cross-sectional view of the electric motor according to Embodiment 1.

[0015] Figure 2 This is a top view showing the rotor of Embodiment 1.

[0016] Figure 3 This is a top view showing the stator core of the electric motor according to Embodiment 1.

[0017] Figure 4 This is a perspective view showing the stator core, insulating components, and insulating film of Embodiment 1.

[0018] Figure 5 This is a cross-sectional view showing the teeth, insulating component, and insulating film of Embodiment 1.

[0019] Figure 6 This is a cross-sectional view showing the teeth, insulating components, insulating film, and windings of Embodiment 1.

[0020] Figure 7This is a cross-sectional view showing the stepped portion of the tooth in Embodiment 1 and the surrounding insulating material and insulating film.

[0021] Figure 8 This is a cross-sectional view showing the teeth, insulating component, and insulating film of Comparative Example 1.

[0022] Figure 9 This is a cross-sectional view showing the teeth, insulating components, insulating film, and windings of Comparative Example 1.

[0023] Figure 10 This is a cross-sectional view showing the teeth, insulating parts, and insulating film of Comparative Example 2.

[0024] Figure 11 This is a schematic diagram showing the winding state of the winding in Comparative Example 2.

[0025] Figure 12 It is a graph showing the relationship between the size of the stepped section of the tooth and the rate of increase in iron loss.

[0026] Figure 13 This is a graph showing the relationship between the size of the stepped portion of the tooth and the rate of increase in copper loss.

[0027] Figure 14 It is a graph showing the relationship between the size of the stepped section of the tooth and the rate of increase in iron loss and copper loss.

[0028] Figure 15 The diagram shows a cross-sectional view (A) of the tooth, insulating element, insulating film, and winding in Embodiment 2, and a cross-sectional view (B) of the stepped portion of the tooth and the insulating element and insulating film surrounding it.

[0029] Figure 16 It is a graph showing the relationship between the width of the stepped portion of the tooth and the rate of increase in iron loss.

[0030] Figure 17 This is a graph showing the relationship between the width of the tooth step and the rate of increase in copper loss.

[0031] Figure 18 It is a graph showing the relationship between the width of the tooth step and the rate of increase in total wear.

[0032] Figure 19 This is a cross-sectional view showing the teeth, insulating component, and insulating film of embodiment 3.

[0033] Figure 20 This is a cross-sectional view showing the stepped portion of the tooth in Embodiment 3 and the surrounding insulating material and insulating film.

[0034] Figure 21 This is a cross-sectional view showing the stepped portion of the tooth in embodiment 4 and the surrounding insulating material and insulating film.

[0035] Figure 22These are schematic diagrams (A) illustrating the winding method of the winding to the insulating film in embodiment 4, and perspective views (B) showing the overall insulating film disposed in a slot.

[0036] Figure 23 It is a diagram used to illustrate the tension of the windings acting on the insulator.

[0037] Figure 24 This is a cross-sectional view showing the stepped portion of the tooth in embodiment 5 and the surrounding insulating material and insulating film.

[0038] Figure 25 This is a cross-sectional view showing the stepped portion of the tooth and the surrounding insulating member and insulating film of a modified example of embodiment 5.

[0039] Figure 26 This is a cross-sectional view showing the teeth, insulating component, and insulating film of embodiment 6.

[0040] Figure 27 This is a cross-sectional view showing the stepped portion of the tooth in embodiment 7 and the surrounding insulating material and insulating film.

[0041] Figure 28 This is a cross-sectional view showing the stepped portion of the tooth in embodiment 7 and the surrounding insulating material and insulating film.

[0042] Figure 29 This is a cross-sectional view showing the teeth, insulating element, and insulating film of embodiment 8.

[0043] Figure 30 This is a cross-sectional view showing the stepped portion of the tooth in embodiment 8 and the insulating member and insulating film surrounding it.

[0044] Figure 31 This is a cross-sectional view showing the teeth, insulating component, and insulating film of embodiment 9.

[0045] Figure 32 This is a cross-sectional view showing the stepped portion of the tooth in embodiment 9 and the insulating member and insulating film surrounding it.

[0046] Figure 33 This is a cross-sectional view showing the stepped portion of the tooth in embodiment 10 and the insulating member and insulating film surrounding it.

[0047] Figure 34 This is a cross-sectional view showing the stepped portion of the tooth and the surrounding insulating member and insulating film in another structural example of embodiment 10.

[0048] Figure 35 This is a cross-sectional view showing the stepped portion of the tooth and the surrounding insulating member and insulating film in another structural example of embodiment 10.

[0049] Figure 36This is a longitudinal sectional view of a compressor with an electric motor to which various embodiments and modifications can be applied.

[0050] Figure 37 It means that it can be applied. Figure 36 A diagram of the refrigeration cycle of a compressor. Detailed Implementation

[0051] Implementation method 1.

[0052] <Structure of an electric motor>

[0053] First, the electric motor 3 of Embodiment 1 will be described. Figure 1 This is a cross-sectional view of the electric motor 3 in Embodiment 1. Figure 1 The motor 3 shown is a permanent magnet embedded synchronous motor, for example, used in compressor 8 ( Figure 36 ).

[0054] The electric motor 3 has a shaft 90 serving as a rotation axis, a rotor 5 fixed to the shaft 90, and a stator 1 arranged to surround the rotor 5. An air gap of, for example, 0.3 to 1.0 mm is formed between the stator 1 and the rotor 5. The stator 1 is assembled into the compressor 8 described later. Figure 36 The inner side of the cylindrical frame 81.

[0055] Hereinafter, the direction of the rotation center of rotor 5, that is, the central axis Ax which is the central axis of shaft 90, is defined as "axial". The radial direction centered on the central axis Ax is defined as "radial". The circumferential direction centered on the central axis Ax is defined as "circumferential".

[0056] <Structure of the rotor>

[0057] Figure 2 This is a cross-sectional view of rotor 5. Rotor 5 has an annular rotor core 50 centered on the central axis Ax and permanent magnets 55 mounted on the rotor core 50. The rotor core 50 has multiple laminated elements stacked along the axial direction. The laminated elements are, for example, electromagnetic steel plates. The thickness of the laminated elements is 0.1 to 0.7 mm.

[0058] A center hole 53 is formed at the radial center of the rotor core 50. Shaft 90 ( Figure 1 It is fixed to the center hole 53 of the rotor core 50 by hot pressing or pressing.

[0059] Multiple magnet insertion holes 51 are formed along the outer periphery of the rotor core 50. Each magnet insertion hole 51 contains a permanent magnet 55. Each magnet insertion hole 51 corresponds to one magnetic pole. The rotor core 50 has six magnet insertion holes 51, therefore the rotor 5 has six poles. However, the number of poles of the rotor 5 is not limited to six; two or more poles are acceptable. Alternatively, two or more permanent magnets 55 may be placed in each magnet insertion hole 51.

[0060] The permanent magnet 55 has a width in the circumferential direction and a thickness in the radial direction of the rotor core 50. Each permanent magnet 55 is magnetized in the thickness direction. The permanent magnet 55 is, for example, made of rare earth magnets containing neodymium (Nd), iron (Fe) and boron (B).

[0061] In rare-earth magnets, dysprosium (Dy) can be added to improve coercivity. However, the addition of Dy increases manufacturing costs and also leads to a decrease in remanent flux density. Therefore, it is preferable to keep the Dy content at 4% by weight or less, or to omit Dy altogether. That is, the Dy content is preferably 0 to 4% by weight.

[0062] The circumferential center of the magnet insertion hole 51 is the pole center Pc. A straight line in the radial direction passing through the pole center Pc is called the pole center line. An inter-pole portion Ip is formed between adjacent magnetic poles. Here, the magnet insertion hole 51 extends in a straight line in a direction perpendicular to the pole center line. However, the magnet insertion hole 51 may also extend in a V-shape.

[0063] Magnetic flux barriers 52, serving as gaps, are formed on both circumferential sides of the magnet insertion hole 51. A thin-walled portion is formed between the magnetic flux barriers 52 and the outer periphery of the rotor core 50. To reduce leakage flux between adjacent magnetic poles, the radial width of the thin-walled portion is, for example, set to be the same as the plate thickness of the laminated element.

[0064] A radially elongated slit 54 is formed on the radially outer side of the magnet insertion hole 51. The slit 54 is formed to control the magnetic flux density distribution on the surface of the rotor 5. Here, seven slits 54 are formed symmetrically with respect to the pole center line, but the number and arrangement of the slits 54 are arbitrary. Alternatively, it is not necessary to provide slits 54 on the rotor core 50.

[0065] The riveting portion 56 for fixing the stacked elements is formed at a circumferential position corresponding to the inter-pole portion Ip, and is located radially inward compared to each flux barrier 52. However, the arrangement of the riveting portion 56 is not limited to this position. In addition, the stacked elements of the rotor core 50 can also be fixed by methods other than riveting.

[0066] Through holes 57 and 58 are formed radially inside the magnet insertion hole 51. The circumferential position of the through hole 57 coincides with the pole center Pc, and the circumferential position of the through hole 58 coincides with the inter-pole portion Ip. The through holes 57 and 58 axially penetrate the rotor core 50 and serve as refrigerant passages. Furthermore, the arrangement of the through holes 57 and 58 is not limited to the positions described herein. Alternatively, it may be unnecessary to provide through holes 57 and 58 in the rotor core 50.

[0067] <Structure of the stator>

[0068] like Figure 1 As shown, the stator 1 has a stator core 10 that surrounds the rotor core 50 radially outward and a winding 30 wound around the stator core 10. The stator core 10 has multiple laminated elements stacked axially. The laminated elements are, for example, electromagnetic steel plates. The thickness of the laminated elements is 0.1 to 0.7 mm.

[0069] Figure 3 This is a top view showing the stator core 10, and the frame 81 is also shown. (See attached image.) Figure 3 As shown, the stator core 10 has an annular core back 11 centered on the central axis Ax and N teeth 12 (N being an integer greater than or equal to 2) extending radially inward from the core back 11. The teeth 12 are arranged at constant intervals in the circumferential direction. The number of teeth 12, N, is 9 here, but it is acceptable as long as it is 2 or more.

[0070] The tooth 12 has an extension 121 extending radially inward from the back of the iron core 11 and a tooth tip 122 formed at the end of the extension 121. The circumferential width of the tooth tip 122 is wider than the circumferential width of the extension 121. The tooth tip 122 is connected to the rotor 5 ( Figure 2 Opposite. The radial straight line passing through the circumferential center of tooth 12 is set as the tooth centerline Tc.

[0071] A slot 13 is formed between adjacent teeth 12 in the circumferential direction. The slot 13 is the area for accommodating the winding 30. The number of slots 13 is the same as the number of teeth 12, which is N, and in this case, 9.

[0072] Winding 30 ( Figure 1 The winding 30 is formed by electromagnetic wire and is wound in a concentrated manner on each tooth 12. A current with a frequency corresponding to the rotational speed of the motor 3 flows through the winding 30, generating a rotating magnetic field that makes the rotor 5 rotate.

[0073] The wire diameter of winding 30 and the number of turns wound onto one tooth 12 are determined by requirements such as rotational speed and torque, supply voltage, and cross-sectional area of ​​slot 13. As an example, the wire diameter of winding 30 is 1.0 mm and the number of turns is 80. An insulating part is provided between the stator core 10 and winding 30, which will be described later.

[0074] The stator core 10 is divided into N segmented cores 14 by a segmentation surface 111 formed on the core back 11. Each segmented core 14 includes a tooth 12. The portion of the core back 11 included in each segmented core 14 is also referred to as the core back 110. Adjacent segmented cores 14 in the circumferential direction are connected by riveting portions 112 or welding provided on the outer periphery of the segmentation surface 111.

[0075] When manufacturing the stator 1, the N segmented cores 14 of the stator core 10 are unfolded into a straight line, and the winding 30 is wound onto the teeth 12 using a winding nozzle. After the winding 30 is wound onto the teeth 12, the N segmented cores 14 are bent into a ring shape, and the segmented cores 14 at both ends are fixed by welding or other means to form a ring-shaped stator core 10.

[0076] Furthermore, the stator core 10 is not limited to a structure in which N segmented cores 14 are combined into a ring shape. For example, it can also be an integral core formed by stacking ring-shaped electromagnetic steel plates along the axial direction.

[0077] Figure 4 This is a schematic diagram showing a portion of the stator core 10 (i.e., the segmented core 14) and the insulation. Figure 4 In the diagram, arrow Z represents the central axis Ax ( Figure 1 The direction of () is the axial direction.

[0078] like Figure 4 As shown, the iron core back 11 has an axially oriented end face 11e and an inner circumferential surface 11a facing the groove 13. The tooth 12 has an axially oriented end face 12e and a side face 12a facing the groove 13.

[0079] The end face 11e of the core back 11 and the end face 12e of the tooth 12 are located on the same plane, corresponding to the end face of the stator core 10. These end faces 11e and 12e are perpendicular to the axial direction. The inner circumferential surface 11a of the core back 11 and the side surface 12a of the tooth 12 form the inner surface of the groove 13. These inner circumferential surfaces 11a and side surfaces 12a are parallel to the axial direction.

[0080] A stepped portion 12S of tooth 12 is formed between the end face 12e and the side face 12a of tooth 12. The stepped portion 12S is composed of a bottom surface 12b facing the axial direction and a wall surface 12c facing the groove 13. The bottom surface 12b is perpendicular to the axial direction, and the wall surface 12c is parallel to the axial direction.

[0081] A stepped portion 11S of the iron core back 11 is formed between the end face 11e and the inner peripheral face 11a of the iron core back 11. The stepped portion 11S is composed of a bottom surface 11b facing the axial direction and a wall surface 11c facing the groove 13. The bottom surface 11b is perpendicular to the axial direction, and the wall surface 11c is parallel to the axial direction.

[0082] The segmented core 14 is composed of a first core portion A1 stacked at the axial center and a second core portion A2 stacked at both axial ends. In the second core portion A2, the width of the core back 11 and the width of the teeth 12 are narrower than those of the first core portion A1.

[0083] Insulating members 20 are provided at both ends of the axial direction of the segmented iron core 14. The insulating members 20 are made of resins such as polybutylene terephthalate (PBT) and liquid crystal polymer (LCP). Furthermore, in... Figure 4 Only the insulating member 20 at one end of the axial direction of the split iron core 14 is shown, but the insulating member 20 at the other end is also constructed in the same way.

[0084] Each insulating member 20 has a wall portion 21 mounted on the back of the iron core 11, a main body portion 22 mounted on the extension portion 121 of the tooth 12, and a flange portion 23 mounted on the top of the tooth 122. The wall portion 21 and the flange portion 23 are radially opposite to each other.

[0085] The wall portion 21 is located on the end face 11e of the iron core back 11 and extends axially. The main body portion 22 covers the end face 12e of the extension portion 121 of the tooth 12. The flange portion 23 is located on the end face 12e of the tooth tip 122 of the tooth 12 and extends axially.

[0086] The insulating member 20 also has a protrusion (not shown) that engages with a fitting hole 16 formed on the back of the core 11. The insulating member 20 is fixed to the segmented core 14 by the engagement of the protrusion with the fitting hole 16 on the back of the core 11. Alternatively, the insulating member 20 can also be fixed to the segmented core 14 by methods other than the engagement of the protrusion with the fitting hole 16.

[0087] An insulating film 25 is provided to cover the inner peripheral surface 11a of the iron core back 11 and the side surface 12a of the teeth 12. The insulating film 25 is, for example, a film formed of a resin such as polyethylene terephthalate (PET). The thickness of the insulating film 25 is, for example, 0.1 to 0.3 mm.

[0088] A winding 30 is wound on the main body 22 and the insulating film 25 of the insulating member 20. In addition, the wall portion 21 and the flange portion 23 of the insulating member 20 guide the winding 30 from both radial sides.

[0089] Figure 5 This is a cross-sectional view showing the tooth 12, the insulating element 20, and the insulating film 25, perpendicular to the extending direction of the tooth 12. The view is perpendicular to the extending direction of the tooth 12. Figure 3 The direction of the tooth centerline Tc shown in the diagram and the direction perpendicular to both the axial direction are defined as the "tooth width direction".

[0090] The insulating member 20 covers the end face 12e of the tooth 12. The insulating member 20 has a top surface 201 facing the side opposite to the tooth 12 in the axial direction, a side surface 202 facing the groove 13, and a curved surface 203 extending from the top surface 201 to the side surface 202. The top surface 201 is also referred to as the first surface, the side surface 202 as the second surface, and the curved surface 203 as the third surface.

[0091] The insulating element 20 has a thickness T in the axial direction. The thickness T is the distance from the end face 12e of the tooth 12 to the top surface 201 of the insulating element 20.

[0092] The insulating film 25 covers the side surface 12a of the tooth 12. Additionally, as described later, the insulating film 25 also covers the side surface 202 of the insulating member 20.

[0093] For reference Figure 4 As explained, the tooth 12 has a stepped portion 12S between the end face 12e and the side face 12a. The stepped portion 12S has a bottom surface 12b facing the axial direction and a wall surface 12c facing the groove 13.

[0094] Figure 6 This is a cross-sectional view of the tooth 12, the insulator 20, the insulating film 25, and the winding 30, perpendicular to the extending direction of the tooth 12. The winding 30 is wound around the tooth 12 with the insulator 20 and the insulating film 25 in between.

[0095] A winding bulge H1 is formed between the winding 30 and the insulating film 25. The winding bulge H1 is largest at the center of the insulating film 25 in the axial direction. In addition, a winding bulge H2 is formed between the winding 30 and the top surface 201 of the insulating member 20. The winding bulge H2 is largest at the center of the top surface 201 in the tooth width direction.

[0096] Figure 7 This is a cross-sectional view showing the stepped portion 12S of the tooth 12 and the surrounding insulating member 20 and insulating film 25. The stepped portion 12S has a depth D in the axial direction. The depth D is the axial distance from the bottom surface 12b of the stepped portion 12S to the end face 12e of the tooth 12.

[0097] The stepped portion 12S has a width W in the tooth width direction (i.e., the direction perpendicular to the extension direction and axial direction of the tooth 12). The width W is the distance from the wall surface 12c of the stepped portion 12S to the side surface 12a of the tooth 12.

[0098] Furthermore, a gap is provided between the bottom surface 12b of the stepped portion 12S and the insulating member 20. This gap is a spatial portion. The axial length of the gap is defined as the gap length L1. The gap length L1 is the axial distance from the bottom surface 12b of the stepped portion 12S to the insulating member 20. Figure 7 In the example shown, the gap length L1 is equal to the depth D of the step portion 12S (D=L1).

[0099] In addition, as will be discussed later Figure 15 As shown in (B), when a portion of the insulating member 20 protrudes towards the step portion 12S, the gap length L1 is shorter than the depth D of the step portion 12S (L1 < D). This will be explained in Embodiment 2.

[0100] The insulating film 25 covers the side surface 12a of the tooth 12 and overlaps with the groove 13 side of the insulating member 20 through the step portion 12S. The portion of the insulating film 25 that overlaps with the insulating member 20 is called the overlapping portion 25a.

[0101] In a cross section perpendicular to the extension direction of tooth 12, the length of the overlap between insulating film 25 and insulating member 20, i.e. the length of the overlapping portion 25a, is called the overlap length L0.

[0102] The overlapping portion 25a of the insulating film 25 is in Figure 7 It contacts the side 202 of the insulating element 20, but may also further contact the curved surface 203 (see reference). Figure 24 ).

[0103] <Comparative Example 1>

[0104] Figure 8 This is a cross-sectional view of the tooth 12H, the insulating element 20, and the insulating film 25 of Comparative Example 1, perpendicular to the extending direction of the tooth 12H. Figure 9 This is a cross-sectional view showing the winding state of the winding 30 towards the tooth 12H in Comparative Example 1. Figure 8 , 9 In the text, the structural elements of Comparative Example 1 are also labeled with the same reference numerals as those of the structural elements of Embodiment 1.

[0105] like Figure 8 As shown, the tooth 12H of Comparative Example 1 does not have a stepped portion between the side surface 12a and the end surface 12e. That is, a 90-degree angle is formed between the side surface 12a and the end surface 12e of the tooth 12H.

[0106] Insulation between the stator core 10 and the winding 30 is achieved by an insulating member 20 covering the end face 12e of the tooth 12H and an insulating film 25 covering the side surface 12a of the tooth 12H. The insulating film 25 overlaps with the insulating member 20 in the area where it protrudes axially from the end face 12e of the tooth 12H.

[0107] When the same resin molded body as the insulating member 20 is used to cover the side surface 12a of the tooth 12H, the resin molded body must be molded to a uniform thinness, thus increasing manufacturing costs. In Comparative Example 1, since the side surface 12a of the tooth 12H is covered with an insulating film 25, manufacturing costs can be reduced. In addition, since the insulating film 25 is thinner than the resin molded body, the wound area within the groove 13 can be expanded, improving motor efficiency.

[0108] Here, the overlap length L0 between the insulating film 25 and the insulating member 20 is set to be greater than the insulation distance required for the insulation between the stator core 10 and the winding 30. To ensure the overlap length L0, the insulating member 20 needs to have a sufficient thickness T.

[0109] As the thickness T of the insulation 20 increases, the circumference of the winding 30 increases. The circumference of the winding 30 refers to the length of one turn of the winding 30 wound around one tooth 12H. The portion of the winding 30 wound around the insulation 20 does not contribute to torque generation; therefore, as the thickness T of the insulation 20 increases, the length of the portion of the winding 30 that does not contribute to torque generation increases.

[0110] The winding 30 is made of copper or aluminum wire, but the price of copper wire has risen due to the increasing demand for motors used in electric vehicles. Therefore, as the circumference of the winding 30 increases, the manufacturing cost rises significantly. In addition, aluminum wire has a higher resistance than copper wire, so as the circumference of the winding 30 increases, the copper loss increases.

[0111] <Comparative Example 2>

[0112] Figure 10 This is a cross-sectional view of the tooth 12, the insulating element 20H and the insulating film 25 of Comparative Example 2, perpendicular to the extending direction of the tooth 12. Figure 11 This is a cross-sectional view showing the winding state of the winding 30 towards the tooth 12 in Comparative Example 2. Figure 11 In the text, the structural elements of Comparative Example 2 are also labeled with the same reference numerals as those of the structural elements of Embodiment 1.

[0113] like Figure 11 As shown, in Comparative Example 2, similar to Embodiment 1, a stepped portion 12S is provided between the end face 12e and the side face 12a of the tooth 12. The stepped portion 12S has a depth D in the axial direction and a width W in the tooth width direction.

[0114] The insulating member 20H has a thin-walled portion 20T that protrudes from the end face 12e of the tooth 12 toward the stepped portion 12S. The thin-walled portion 20T is formed to contact the bottom surface 12b and the wall surface 12c of the stepped portion 12S. That is, there is no gap between the stepped portion 12S and the insulating member 20H.

[0115] The insulating film 25 overlaps with the insulating member 20H, which includes the thin-walled portion 20T. The overlap length L0 between the insulating film 25 and the insulating member 20H is set to be greater than or equal to the insulation distance required for the insulation between the stator core 10 and the winding 30.

[0116] In Comparative Example 2, the axial length of the thin-walled portion 20T of the insulating member 20H is included in the overlap length L0. Therefore, by increasing the axial length (i.e., the protrusion amount) of the thin-walled portion 20T, the thickness T of the insulating member 20H can be reduced, and the circumference of the winding 30 can be shortened.

[0117] On the other hand, in order to extend the axial length of the thin-walled portion 20T, it is necessary to increase the depth D of the stepped portion 12S of the tooth 12. If the depth D of the stepped portion 12S is increased, the magnetic circuit inside the tooth 12 will become narrower, the magnetic reluctance inside the tooth 12 will increase, and the iron loss may increase.

[0118] Furthermore, increasing the depth D of the step portion 12S can lead to magnetic saturation around the step portion 12S, potentially reducing the torque constant. When the torque constant decreases, the current required to generate the desired torque increases, potentially increasing copper losses.

[0119] <Function of Implementation Method 1>

[0120] In contrast, in implementation method 1, such as Figure 7 As shown, a gap is provided between the bottom surface 12b of the stepped portion 12S of the tooth 12 and the insulating member 20. The overlap length between the insulating film 25 and the insulating member 20, i.e., the overlap length L0, is equivalent to the surface distance. The surface distance refers to the length along the surface of the insulator between two insulating objects.

[0121] Here, the contact point where the opposing surface 204 of the insulating member 20 facing the step portion 12S contacts the insulating film 25 is designated as P. The shortest distance from the contact point P to the step portion 12S corresponds to the spatial distance. The spatial distance refers to the shortest distance through the space between two insulating objects.

[0122] The shortest distance from point P to step 12S is the shorter of the distance from point P to bottom surface 12b and the distance from point P to wall surface 12c. The distance from point P to bottom surface 12b is the gap length L1. The gap length L1 is longer than 0 mm, but will not exceed the depth D of step 12S, therefore it falls within the range of 0 < L1 ≤ D. The distance from point P to wall surface 12c is the width W of step 12S. Therefore, the shorter of the gap length L1 and the width W of step 12S corresponds to the spatial distance.

[0123] The sum of the aforementioned surface distance and spatial distance is set to be greater than or equal to the insulation distance required for the insulation between the stator core 10 and the winding 30. The insulation distance required for the insulation between the stator core 10 and the winding 30 is determined according to the safety standards of the country where the electric motor 3 is used.

[0124] Japan's Electrical Appliance and Material Safety Law, which serves as a safety standard, requires that the insulation distance between the stator core and windings of an air conditioner motor be at least 2.0 mm. Furthermore, in the United States, for example, based on the UL standard established by the U.S. Insurers Safety Testing Institute, the insulation distance is required to be at least 1.0 mm.

[0125] In Embodiment 1, the sum of the smaller of the overlap length L0 between the insulating film 25 and the insulating member 20, the gap length L1, and the width W of the step portion 12S is sufficient to meet or exceed the required insulation distance. That is, L0 + L1 or L0 + W is sufficient to meet or exceed the required insulation distance (e.g., 2.0 mm or more).

[0126] Therefore, the overlap length L0 can be made shorter than the required insulation distance. Thus, compared to Comparative Example 2 ( Figure 11 Compared to the previous method, this method can make the depth D of the step portion 12S shallower, thus suppressing the increase in magnetic resistance.

[0127] Additionally, it is not necessary to follow the method described in Comparative Example 1 ( Figure 9 By increasing the thickness T of the insulation component 20, the circumference of the winding 30 can be shortened.

[0128] Here, in the motor 3, the insulation distance required for the insulation between the stator core 10 and the winding 30 is not determined by the volume of the motor 3 but by the driving voltage, etc., and is therefore constant and independent of the axial length of the stator core 10.

[0129] Figure 12 and Figure 13 This is a graph showing the analytical results of the loss variation when the dimensions of the stepped portion 12S are changed. In the analysis, the depth D and width W of the stepped portion 12S are set to be the same (D=W), and they are varied from 0.00mm to 2.00mm. The axial length of the stator core 10 is set to three different values: 25mm, 35mm, and 45mm. The gap length L1 is set to be the same as the depth D and width W of the stepped portion 12S (i.e., D=W=L1).

[0130] Figure 12 This represents the relationship between the dimensions of the step section 12S and the rate of increase in iron loss. The horizontal axis represents the depth D and width W of the step section 12S, and the vertical axis represents the rate of increase in iron loss. The rate of increase in iron loss is a relative value of iron loss based on the iron loss when D=W=0.

[0131] Figure 13 This represents the relationship between the dimensions of the stepped section 12S and the copper loss increase rate. The horizontal axis represents the depth D and width W of the stepped section 12S, and the vertical axis represents the copper loss increase rate. The copper loss increase rate is a relative value of copper loss based on the copper loss when D=W=0.

[0132] like Figure 12As shown, the shorter the axial length of the stator core 10, the more significant the increase in iron loss caused by the step portion 12S. Furthermore, as... Figure 13 As shown, the shorter the axial length of the stator core 10, the more significant the increase in copper loss caused by the step portion 12S. This is because, as the axial length of the stator core 10 decreases, the proportion of the step portion 12S in the cross-section of the tooth 12 increases.

[0133] Figure 14 It is shown together Figure 12 , 13 The graph shown in the analysis results illustrates the increase rate of iron loss and copper loss when the axial length of stator core 10 is 25 mm.

[0134] like Figure 14 As shown, iron loss increases with the increase of depth D and width W of step 12S, but the gradient becomes gentler at the point where depth D and width W are 1.25 mm. On the other hand, copper loss increases with the increase of depth D and width W of step 12S, but the gradient becomes steeper at the point where depth D and width W are 1.25 mm.

[0135] That is, in the curves representing the changes in iron loss and the curves representing the changes in copper loss, the points where the depth D and width W of the step 12S are 1.25 mm are both inflection points.

[0136] This is because when the depth D and width W of the step portion 12S exceed 1.25 mm, magnetic saturation occurs within the tooth 12. When magnetic saturation occurs, iron losses saturate, but the torque constant decreases due to magnetic saturation, thus increasing the current required to generate the desired torque and increasing copper losses.

[0137] According to the results, if at least one of the depth D and width W of the step portion 12S is less than 1.25 mm, the effect of suppressing magnetic saturation in the tooth 12 can be obtained. If both the depth D and width W of the step portion 12S are less than 1.25 mm, the effect of suppressing magnetic saturation is particularly high.

[0138] In addition, Figure 12 , 13 In the curves showing the stator core 10 with an axial length of 35mm and 45mm, the point where the depth D and width W of the step portion 12S are 1.25mm also become an inflection point. Therefore, it can be seen that if at least one of the depth D and width W of the step portion 12S (more preferably both) is 1.25mm or less, the generation of magnetic saturation can be suppressed, and the increase of iron loss and copper loss can be suppressed.

[0139] That is, by setting the sum of the shortest distance (i.e., spatial distance) from the contact point P where the opposing surface 204 of the insulating member 20 contacts the insulating film 25 to the step portion 12S and the overlap length L0 (i.e., surface distance) to be greater than or equal to the required insulation distance, the depth D of the step portion 12S can be made relatively shallow, and the increase in magnetic reluctance within the tooth 12 can be suppressed. Moreover, by ensuring that at least one (more preferably both) of 0 < D ≤ 1.25 mm and 0 < W ≤ 1.25 mm is true, the generation of magnetic saturation within the tooth 12 can be suppressed.

[0140] The stepped portion 12S of tooth 12 preferably has a depth D that is greater than or equal to the width W (i.e., D ≥ W), and more preferably has a depth D that is greater than the width W (i.e., D > W). The rationale is explained in Embodiment 2. Figures 16-18 Please provide an explanation.

[0141] Next, the thermal shrinkage of the insulating film 25 will be explained. The insulating film 25, formed from resins such as PET, has the property of shrinking due to heat. The coefficient of thermal expansion α of the insulating film 25 is 60 × 10⁻⁶. -6 / ℃≤α≤120×10 -6 Within the range of / ℃.

[0142] In the stator 1, heat is generated by energizing the winding 30, and the amount of heat generated varies depending on the specifications of the motor 3 or the operating conditions. Therefore, the allowable temperature range of the winding 30 is usually set according to the specifications of the motor 3, so that the motor 3 is operated in a manner that the temperature of the winding 30 does not exceed the upper limit temperature Tmax of the allowable temperature range.

[0143] On the other hand, even if the temperature of the winding 30 is below the upper limit temperature Tmax, the amount of thermal shrinkage of the insulating film 25 varies depending on the temperature, and the aforementioned insulation distance changes.

[0144] Therefore, the insulation distance can be set assuming that the winding 30 is heated to the upper limit temperature Tmax (i.e., the insulation film 25 has the greatest thermal shrinkage). Alternatively, multiple stators 1 with different sizes of insulation film 25 can be prepared, and the optimal stator 1 can be selected by considering the specifications of the motor 3 and the operating conditions.

[0145] In contrast, in implementation method 1, such as Figure 5 As shown, the spatial distance is ensured by the gap between the stepped portion 12S of the tooth 12 and the insulating member 20. Therefore, the minimum value of the width W of the stepped portion 12S is preferably 1 / 2 or more of the maximum axial shrinkage X of the insulating film 25, i.e., X / 2 (i.e., W≥X / 2).

[0146] If the axial length of the insulating film 25 at room temperature (20℃) is set as Li (mm), the coefficient of thermal expansion of the insulating film 25 is set as α, and the upper limit of the allowable temperature range is set as Tmax, then the maximum axial shrinkage X (mm) of the insulating film 25 is represented by X=Li×α×(Tmax-20).

[0147] Therefore, the width W of the step portion 12S preferably satisfies W≥Li×α×(Tmax-20) / 2. In this way, the reduction in surface distance (more specifically, the reduction in overlap length L0) caused by thermal shrinkage on each side of the axial direction of the insulating film 25 can be compensated by the width W of the step portion 12S.

[0148] In addition, refer to Figure 7 The insulation structure for the stator core 10 and winding 30 described herein only needs to be provided at at least one axial end of the stator core 10; insulation at the other end can also be provided using other structures. Alternatively, an inclined surface can be provided instead of the bent surface 203 of the insulating member 20 (see reference). Figure 25 ).

[0149] <Effects of the Implementation Method>

[0150] As described above, the stator 1 of Embodiment 1 includes: a stator core 10 having an annular core back 11, teeth 12 extending radially inward from the core back 11, and slots 13 adjacent to the teeth 12 in the circumferential direction; an insulating portion disposed on the teeth 12; and a winding 30 wound around the teeth 12 with the insulating portion in between. The teeth 12 have an axially facing end face 12e, a side face 12a facing the slots 13, and a stepped portion 12S formed between the end face 12e and the side face 12a. The insulating portion includes: an insulating member 20 disposed on the end face 12e of the teeth 12; and an insulating film 25 covering the side face 12a of the teeth 12 and a portion of the insulating member 20. The stepped portion 12S has a depth D in the axial direction and a width W in the tooth width direction (i.e., a direction perpendicular to both the extension direction of the teeth 12 and the axial direction). A gap is provided axially between the stepped portion 12S and the insulating member 20. In a plane perpendicular to the extending direction of tooth 12, the sum of the shortest distance from the contact point P where the insulating film 25 contacts the opposing surface 204 of the insulating member 20 facing the step portion 12S, to the step portion 12S, and the overlap length L0 of the insulating film 25 and the insulating member 20, is greater than or equal to the insulation distance required for the insulation between the stator core 10 and the winding 30 (e.g., 2.0 mm). Regarding the depth D and width W of the step portion 12S, at least one of 0 < D ≤ 1.25 mm and 0 < W ≤ 1.25 mm is true.

[0151] Thus, the sum of the shortest distance (i.e., spatial distance) from the contact point P to the step portion 12S and the overlap length L0 (i.e., surface distance) is greater than or equal to the insulation distance. Therefore, even if the depth D of the step portion 12S is relatively shallow, insulation between the stator core 10 and the winding 30 can be ensured. This suppresses the increase in magnetic reluctance within the tooth 12 and inhibits the decrease in motor efficiency. Furthermore, regarding the depth D and width W of the step portion 12S, at least one (more preferably both) of 0 < D ≤ 1.25 mm and 0 < W ≤ 1.25 mm is satisfied. This suppresses the generation of magnetic saturation in the tooth 12, thereby suppressing the increase in iron and copper losses and inhibiting the decrease in motor efficiency.

[0152] Furthermore, in Embodiment 1, since the depth D of the step portion 12S is the same as the gap length L1 (i.e., D=L1), the shape of the insulating member 20 can be simplified, thereby simplifying the molding process of the insulating member 20.

[0153] Implementation method 2.

[0154] Figure 15 (A) is a cross-sectional view showing the tooth 12, insulating member 20A, insulating film 25, and winding 30 in Embodiment 2. In Embodiment 2, as Figure 15 As shown in (A), the insulating member 20A has a thin-walled portion 20T that protrudes toward the stepped portion 12S.

[0155] Figure 15 (B) is a cross-sectional view showing the stepped portion 12S of tooth 12 and the surrounding insulating member 20A and insulating film 25. As described in Embodiment 1, the stepped portion 12S has a depth D in the axial direction and a width W in the tooth width direction.

[0156] The thin-walled portion 20T of the insulating member 20A protrudes in a manner opposite to the wall surface 12c of the stepped portion 12S of the tooth 12. The portion of the insulating member 20A other than the thin-walled portion 20T is also referred to as the main body portion.

[0157] A gap is formed between the bottom surface 12b of the stepped portion 12S and the thin-walled portion 20T of the insulating member 20A. Since the insulating member 20A has a thin-walled portion 20T, the axial length of the gap between the bottom surface 12b of the stepped portion 12S and the insulating member 20A, i.e., the gap length L1, is shorter than the depth D of the stepped portion 12S. That is, 0 < L1 < D holds true.

[0158] The insulating film 25 contacts the side surface 202 of the insulating member 20A. The length of the side surface 202 of the insulating member 20A is longer than that of the thin-walled portion 20T compared to Embodiment 1. Therefore, the overlap length L0 between the insulating film 25 and the insulating member 20A is longer than that of Embodiment 1.

[0159] Let P be the contact point where the opposing surface 205 of the thin-walled portion 20T facing the stepped portion 12S contacts the insulating film 25. The shortest distance from the contact point P to the stepped portion 12S corresponds to the spatial distance. In other words, the shorter of the width W of the stepped portion 12S and the gap length L1 corresponds to the aforementioned spatial distance.

[0160] The sum of the aforementioned surface distance and spatial distance is set to be greater than or equal to the insulation distance required for the insulation between the stator core 10 and the winding 30. That is, the shorter of L0+W and L0+L1 is set to be greater than or equal to the required insulation distance.

[0161] Here, the shape of the stepped portion 12S of the tooth 12, i.e., the relationship between the depth D and the width W, will be explained. Figures 16-18 This is a graph showing the analytical results of the change in loss when the product of the depth D and width W of the step 12S is kept constant and the width W of the step 12S is varied.

[0162] In the analysis, the product of the depth D and width W of the step portion 12S is kept constant at 1.25mm × 1.25mm, while the width W of the step portion 12S varies from 0.25mm to 1.25mm. Furthermore, the axial length of the stator core 10 is set to three different values: 25mm, 35mm, and 45mm.

[0163] Furthermore, the gap length L1 is set to be the same as the depth D and width W of the step portion 12S (i.e., L1=D=W). That is, as in Embodiment 1. Figure 7 As shown, the insulating member 20A is designed to not protrude toward the step portion 12S side compared to the end face 12e of the tooth 12.

[0164] Figure 16 This plot shows the relationship between the width W of the step section 12S and the rate of increase in iron loss. The horizontal axis represents the width W of the step section 12S, and the vertical axis represents the rate of increase in iron loss. The rate of increase in iron loss is a relative value of iron loss based on the iron loss when W=D=1.25mm.

[0165] Figure 17 This plot shows the relationship between the width W of the step section 12S and the copper loss increase rate. The horizontal axis represents the width W of the step section 12S, and the vertical axis represents the copper loss increase rate. The copper loss increase rate is a relative value of copper loss based on the copper loss when W=D=1.25mm.

[0166] Figure 18 This represents the relationship between the width W of the step section 12S and the rate of increase of the total loss (iron and copper). The horizontal axis represents the width W of the step section 12S, and the vertical axis represents the rate of increase of the total loss. The rate of increase of the total loss is a relative value of the total loss based on the total loss when W=D=1.25mm.

[0167] When the width W of the step 12S is reduced, the iron loss increases slightly (see reference). Figure 16 However, copper losses were significantly reduced (refer to...). Figure 17 ),like Figure 18 As shown, the total loss is reduced. This is because, when the product of the width W and the depth D of the step portion 12S is kept constant, the reduction in magnetic saturation caused by the reduction in width W is greater than the reduction in magnetic saturation caused by the reduction in depth D.

[0168] according to Figures 16-18 As a result, in order to reduce total losses, it is preferable that the width W of the step portion 12S is small and the depth D is deep. That is, it is preferable that the width W of the step portion 12S is less than or equal to the depth D (i.e., W ≤ D), and more preferably the width W is smaller than the depth D (i.e., W < D). In other words, the step portion 12S is preferably a shape that is longer in the axial direction.

[0169] Preferably, D≥W applies to both the stepped portion 12S in Embodiments 1 and 2. On the other hand, in Embodiment 2, compared with Embodiment 1, the overlap length L0 becomes longer by an amount corresponding to the protrusion of the thin-walled portion 20T, and the gap length L1 becomes shorter by an amount corresponding to the protrusion of the thin-walled portion 20T.

[0170] Therefore, in Embodiment 2, the depth D and width W of the step portion 12S can be determined in a way that reduces iron loss and copper loss, and the protrusion amount of the thin-walled portion 20T can be determined in a way that obtains the desired surface distance and spatial distance.

[0171] exist Figure 15 In (B), the shortest distance from the contact point P to the step portion 12S is the shorter of the gap length L1 and the width W of the step portion 12S. When the gap length L1 is longer than the width W of the step portion 12S (i.e., L1 > W), the width W of the step portion 12S becomes the shortest distance from the contact point P to the step portion 12S. In this case, the gap length L1 cannot be used as the spatial distance. Therefore, the gap length L1 is preferably less than or equal to the width W of the step portion 12S (i.e., L1 ≤ W).

[0172] The width of the thin-walled portion 20T of the insulating member 20A is preferably the same as the width W of the stepped portion 12S. Since the insulating member 20A is a resin molded body, if the width of the thin-walled portion 20T is too thin, the moldability will be reduced, requiring increased pressure during injection molding, thus increasing processing costs.

[0173] When the insulating part 20A is formed of LCP or PBT, if the width of the thin-walled portion 20T is 0.3 mm or more, sufficient moldability can be obtained without increasing the pressure applied during injection molding. Therefore, processing costs can be reduced.

[0174] As described in Embodiment 1, the upper limit of the width W of the step portion 12S is 1.25 mm, so the range of the width W of the step portion 12S can be represented by 0.3 mm ≤ W ≤ 1.25 mm.

[0175] Apart from the points mentioned above, the stator of Embodiment 2 is constructed in the same manner as the stator 1 of Embodiment 1. Furthermore, the insulating member 20A may also have an inclined surface 206 (see reference). Figure 25 ) to replace the curved surface 203.

[0176] As explained above, in Embodiment 2, the thin-walled portion 20T of the insulating member 20A protrudes towards the stepped portion 12S from the end face 12e of the tooth 12, thus increasing the overlap length L0 between the insulating film 25 and the insulating member 20A. This extends the surface distance, making it easier to ensure the insulation distance between the stator core 10 and the winding 30.

[0177] Furthermore, by making the width W of the step portion 12S of the tooth 12 less than or equal to the depth D (i.e., W≤D), it is possible to suppress the generation of magnetic saturation within the tooth 12 and suppress the increase of iron loss and copper loss.

[0178] Furthermore, by ensuring that the width W of the step portion 12S of the tooth 12 satisfies 0.3mm≤W≤1.25mm, it is possible to suppress the generation of magnetic saturation within the tooth 12 without increasing manufacturing costs.

[0179] In addition, the gap length L1 between the step portion 12S and the insulating member 20A is less than or equal to the width W of the step portion 12S (i.e., L1 ≤ W), so the gap length L1 can be used as a spatial distance, and the insulation distance can be easily ensured.

[0180] Implementation method 3.

[0181] Figure 19 This is a cross-sectional view of the tooth 12, the insulating member 20, and the insulating film 25 in Embodiment 3, perpendicular to the extending direction of the tooth 12. In Embodiment 3, the insulating film 25 is configured to enter the space between the step portion 12S of the tooth 12 and the insulating member 20.

[0182] Figure 20 This is a cross-sectional view showing the stepped portion 12S of tooth 12 and the surrounding insulating member 20 and insulating film 25. (See image below.) Figure 20 As shown, the insulating film 25 of Embodiment 3 has an entry portion 25b that enters the space between the stepped portion 12S of the tooth 12 and the insulating member 20. The structures of the tooth 12 and the insulating member 20 are as described in Embodiment 1.

[0183] The entry portion 25b of the insulating film 25 has a first portion B1 that contacts the bottom surface 12b of the stepped portion 12S, a second portion B2 that contacts the wall surface 12c of the stepped portion 12S, and a third portion B3 that contacts the opposing surface 204 of the insulating member 20. In addition, the aforementioned overlapping portion 25a is continuously formed on the end side of the entry portion 25b of the insulating film 25.

[0184] In the manufacturing process of the electric motor 3, when the stator core 10 is formed by stacking electromagnetic steel plates, a tolerance is set for the axial length of the stator core 10. When the axial length of the stator core 10 is lower than the lower limit of the tolerance, it is difficult to adjust the axial length thereafter. Therefore, in practice, the electromagnetic steel plates are stacked such that the axial length of the stator core 10 is close to the upper limit of the tolerance. If the upper limit of the tolerance is exceeded, the axial length of the stator core 10 is brought within the tolerance by peeling off the electromagnetic steel plates at the axial ends of the stator core 10.

[0185] On the other hand, when the electromagnetic steel plate at the axial end of the stator core 10 is removed, the depth D of the step portion 12S of the tooth 12 decreases, and the gap length L1 ( Figure 7 The number of [something] also decreases. Therefore, the spatial distance becomes shorter.

[0186] As a redundant design taking this situation into account, the thickness T of the insulation member 20 needs to be further increased while the surface distance is increased by the amount that the spatial distance is shortened. However, increasing the thickness T of the insulation member 20 will lead to an increase in the circumference of the winding 30, which is therefore not preferred.

[0187] like Figure 20 As shown, in Embodiment 3, the entry portion 25b of the insulating film 25 enters the space between the stepped portion 12S of the tooth 12 and the insulating member 20. Furthermore, the third portion B3 of the entry portion 25b contacts the opposing surface 204 of the insulating member 20, and the length of this contact portion is the width W of the stepped portion 12S. This is the length of the insulators in contact with each other, and is therefore included in the surface distance.

[0188] Therefore, the surface distance in Embodiment 3 is the sum of the overlap length L0 described in Embodiment 1 and the overlap length (i.e., width W) of the overlap between the entry portion 25b of the insulating film 25 and the insulating member 20, i.e., L0+W.

[0189] Therefore, even if the depth D of the step portion 12S of the tooth 12 and the gap length L1 are reduced during the manufacturing process, the surface distance can be extended to ensure sufficient insulation between the stator core 10 and the winding 30.

[0190] Apart from the points mentioned above, the stator of Embodiment 3 is constructed in the same manner as the stator 1 of Embodiment 1. Furthermore, the insulating member 20A of Embodiment 2 may be provided instead of the insulating member 20. Additionally, an inclined surface may be provided instead of the curved surface 203 of the insulating member 20.

[0191] As explained above, in Embodiment 3, since the insulating film 25 has a portion (i.e., the entry portion 25b) of the space between the step portion 12S of the entry tooth 12 and the insulating member 20, the stator core 10 and the winding 30 can be fully insulated regardless of how the depth D of the step portion 12S and the gap length L1 change.

[0192] Implementation method 4.

[0193] Figure 21 This is a cross-sectional view showing the stepped portion 12S of the tooth 12 in Embodiment 4, the surrounding insulating member 20A, and the insulating film 25. In Embodiment 4, the insulating film 25 overlaps not only with the side surface 202 of the insulating member 20A, but also with the curved surface 203.

[0194] The insulating member 20A has a top surface 201 facing axially toward the side opposite to the end face 12e of the tooth 12, a side surface 202 facing the groove 13, and a curved surface 203 extending from the top surface 201 to the side surface 202. The curved surface 203 is, for example, an arc surface.

[0195] Point P1 is designated as the first point, where the inflection point between the side surface 202 and the curved surface 203 of the insulating member 20A is defined. Point P2 is designated as the second point, where the inflection point between the curved surface 203 and the top surface 201 of the insulating member 20A is defined. Points P1 and P2 are defined as the two ends of the curved surface 203. The midpoint between points P1 and P2 along the curved surface 203 is designated as the midpoint P3.

[0196] The insulating member 20A has the thin-walled portion 20T described in Embodiment 2. Alternatively, the insulating member 20 described in Embodiment 1 may be used instead of the insulating member 20A.

[0197] The insulating film 25 has an overlapping portion 25a that overlaps with the side surface 202 of the insulating member 20A and an overlapping portion 25c that overlaps with the curved surface 203 of the insulating member 20A.

[0198] exist Figure 21 In the process, the overlapping portion 25c of the insulating film 25 separates from the curved surface 203 of the insulating member 20A, but through the winding 30, the overlapping portion 25c bends along the surface of the curved surface 203 of the insulating member 20A and contacts the curved surface 203.

[0199] The length L2 of the overlapping portion 25c of the insulating film 25 is preferably shorter than half the distance (i.e., the arc length) from the first point P1 to the midpoint P2 along the curved surface 203.

[0200] In other words, preferably, the overlapping portion 25c of the insulating film 25 extends beyond the midpoint P3 when it is in contact with the curved surface 203. The reason for this will be explained below.

[0201] Figure 22 (A) is a perspective view showing the winding action of the insulating film 25 on both sides of the winding 30 towards the tooth 12. Figure 22 In (A), tooth 12 and insulating component 20A are omitted, and the winding direction of winding 30 is indicated by arrows W1 to W5.

[0202] like Figure 22 As shown in (A), the winding 30 first passes axially within the slot 13 as indicated by arrow W1, then crosses the tooth 12 and moves to the adjacent slot 13 as indicated by arrow W2. Next, after passing within the slot 13 in the opposite direction to arrow W1 as indicated by arrow W3, the winding 30 crosses the tooth 12 and returns to the original slot 13 as indicated by arrow W4, and then passes within the slot 13 in the same direction as arrow W1 as indicated by arrow W5. By repeating this action, the winding 30 is wound onto the tooth 12.

[0203] The insulating film 25 has an inner peripheral surface 11a covering the back of the iron core 11. Figure 4 The first part 251 and the side 12a of the cover tooth 12 () Figure 21 The second part 252 of the insulating film 25 is formed as a single unit. During the winding operation of the winding 30 described above, the second part 252 of the insulating film 25 is stretched towards the center side in the width direction of the tooth 12. The first part 251 and the second part 252 are formed as a single unit, and therefore are also stretched towards the center side of the tooth 12.

[0204] Figure 22 (B) is a perspective view showing the shape of the insulating film 25. The insulating film 25 is as described above... Figure 22 The simplified version is shown in (A), but as Figure 22 As shown in (B), the insulating film 25 covering the inner surface of a groove 13 is formed integrally. That is, the insulating film 25 has two second portions 252 on both sides of the first portion 251 bent at the center 250 of the groove 13.

[0205] If excessive tensile force is applied to the two second parts 252 connected by the first part 251, the position of each second part 252 will be offset, which may affect the winding state of the winding 30 or the insulation state between the stator core 10 and the winding 30.

[0206] Figure 23 This is a schematic diagram illustrating the tension experienced by the winding 30 wound around the insulating member 20A and the insulating film 25. Figure 23The insulating element 20A is the embodiment 2. Figure 15 The insulating element shown in (A) has an insulating film 25 that does not contact the curved surface 203 of the insulating element 20A. The two ends of the curved surface 203 of the insulating element 20A are defined by points P1 and P2.

[0207] A winding bulge H1 is formed between the winding 30 and the insulating film 25, and a winding bulge H2 is formed between the winding 30 and the top surface 201 of the insulating element 20A. Figure 22 When the winding 30 is wound as shown by arrows W1 to W5 in (A), the winding bulge H2 on the insulating member 20A side is larger than the winding bulge H1 on the insulating film 25 side. Therefore, the point Pmax where the tension acting on the winding 30 is the greatest becomes the point Pmax which is shifted from the midpoint P3 of points P1 and P2 towards point P2.

[0208] If the insulating film 25 does not extend to the point of maximum tension Pmax, excessive tensile force can be avoided from acting on the insulating film 25. Therefore, by extending the insulating film 25 beyond the midpoint P3 between points P1 and P2, excessive tensile force can be avoided from acting on the insulating film 25.

[0209] Therefore, in implementation method 4, as Figure 21 As shown, the length L2 of the protrusion of the insulating film 25 from point P1, i.e. the length of the overlapping portion 25c, is set to less than 1 / 2 of the length of the curved surface 203 (i.e., the distance along the curved surface 203 from point P1 to point P2).

[0210] This prevents excessive tensile force from being applied to the insulating film 25 during the winding process of the winding 30, and prevents the insulating film 25 from shifting position. This improves the winding accuracy of the winding 30 and ensures sufficient insulation between the stator core 10 and the winding 30.

[0211] Alternatively, an inclined surface 206 can be provided instead of the curved surface 203 of the insulating member 20A. Figure 25 In this case, the protrusion length of the insulating film 25 from point P1 is also set to less than 1 / 2 of the length of the inclined surface 206 (i.e., the distance between points P1 and P2 along the inclined surface 206), so that the insulating film 25 does not exceed the midpoint P3 of points P1 and P2, thereby preventing excessive tensile force.

[0212] Apart from the points mentioned above, the stator of Embodiment 4 is constructed in the same manner as the stator 1 of Embodiment 1. Furthermore, the insulating member 20 of Embodiment 1 may be provided instead of the insulating member 20A.

[0213] As explained above, in embodiment 4, the insulating film 25 has a portion (i.e., overlapping portion 25c) that overlaps with the curved surface 203 of the insulating member 20A, thus further extending the surface distance and ensuring insulation between the stator core 10 and the winding 30.

[0214] In addition, since the protrusion length of the insulating film 25 from point P1 is set to less than 1 / 2 of the length of the curved surface 203 (i.e., the distance between points P1 and P2 along the curved surface 203), it is possible to prevent excessive tensile force from being applied to the insulating film 25 during the winding process of the winding 30, and to prevent the position of the insulating film 25 from shifting.

[0215] Implementation method 5.

[0216] Figure 24 This is a cross-sectional view of the tooth 12, the insulating member 20B, and the insulating film 25 in Embodiment 5, perpendicular to the extending direction of the tooth 12. In Embodiment 5, the radius of curvature R of the curved surface 203 of the insulating member 20B is equal to or greater than the thickness T of the insulating member 20B.

[0217] Like the insulating member 20A in Embodiment 2, the insulating member 20B has a thin-walled portion 20T protruding toward the step portion 12S. The insulating member 20B also has a top surface 201 facing the side opposite to the tooth 12 in the axial direction, a side surface 202 facing the groove 13, and a curved surface 203 extending from the top surface 201 to the side surface 202. The curved surface 203 is, for example, an arc surface.

[0218] Let point P1 be the inflection point between the curved surface 203 and the side surface 202. Let point P2 be the inflection point between the curved surface 203 and the top surface 201. Points P1 and P2 define the two ends of the curved surface 203. The radius of the arc connecting points P1 and P2 is the radius of curvature R of the curved surface 203.

[0219] The center of curvature C of the curved surface 203 is located within the tooth 12. Therefore, point P1 is located at a position that does not protrude axially from the end face 12e of the tooth 12. In addition, the radius of curvature R of the curved surface 203 is greater than or equal to the thickness T of the insulating member 20B, and more preferably greater than the thickness T. That is, R ≥ T holds true, and more preferably R > T holds true.

[0220] As described in Embodiment 4, the insulating film 25 has an overlapping portion 25c that overlaps with the curved surface 203 of the insulating member 20B. When the winding 30 is wound, the overlapping portion 25c of the insulating film 25 bends along the curved surface 203 of the insulating member 20B.

[0221] In this way, by making the overlapping portion 25c of the insulating film 25 contact the curved surface 203 of the insulating member 20B, the insulation distance can be extended. However, if the thickness T of the insulating member 20B is increased in order to ensure the length of the curved surface 203, the circumference of the winding 30 becomes longer.

[0222] Therefore, in Embodiment 5, the starting position, i.e., point P1, of the curved surface 203 of the insulating member 20B is set to a position opposite to the wall surface 12c of the step portion 12S. This allows the thickness T of the insulating member 20B to be less than or equal to the radius of curvature R of the curved surface 203.

[0223] By reducing the thickness T of the insulation element 20B, the circumference of the winding 30 can be shortened, thereby reducing the amount of winding 30 used and copper loss. In addition, compared with reducing the radius of curvature R of the bending surface 203, the winding bulge of the winding 30 can be reduced, which can improve the reduction effect of winding 30 usage and copper loss.

[0224] Furthermore, since the insulating member 20B has a thin-walled portion 20T that protrudes toward the step portion 12S, it is possible to achieve a structure in which the radius of curvature R of the curved surface 203 is greater than or equal to the thickness T of the insulating member 20B.

[0225] Apart from the points mentioned above, the stator of Embodiment 5 is constructed in the same manner as the stator 1 of Embodiment 1. Furthermore, the insulating film 25 may be configured as described in Embodiment 3.

[0226] As explained above, in embodiment 5, the radius of curvature R of the curved surface 203 of the insulating member 20B and the thickness T of the insulating member 20B satisfy R≥T. Therefore, the thickness T of the insulating member 20B can be reduced to shorten the circumference of the winding 30 and reduce copper loss.

[0227] Furthermore, while a larger radius of curvature R of the curved surface 203 of the insulating element 20B results in less resin material being used to form the insulating element 20B, an excessively large radius of curvature R makes winding the winding 30 difficult. Therefore, the radius of curvature R of the curved surface 203 of the insulating element 20B is preferably 3 mm or less. That is, it is preferable that R ≤ 3 mm.

[0228] The radius of curvature R of the curved surface 203 is not limited to Embodiment 5, but can also be applied to the insulating parts of Embodiments 1 to 4 and Embodiments 6 to 10 described later.

[0229] Variations.

[0230] Figure 25 This is a cross-sectional view of the tooth 12, the insulating member 20C, and the insulating film 25, in a modified example of Embodiment 5, perpendicular to the extending direction of the tooth 12. In Embodiment 5, the insulating member 20C has an inclined surface 206 instead of a curved surface 203. Figure 24 ).

[0231] like Figure 25As shown, the insulating member 20C has a top surface 201 facing the side opposite to the end face 12e of the tooth 12 in the axial direction, a side surface 202 facing the groove 13, and an inclined surface 206 extending from the top surface 201 to the side surface 202.

[0232] The inflection point between the inclined surface 206 and the side surface 202 is designated as point P1. The inflection point between the inclined surface 206 and the top surface 201 is designated as point P2. Points P1 and P2 define the two ends of the inclined surface 206.

[0233] Let the distance in the tooth width direction between points P1 and P2 be distance E1. Let the axial distance between points P1 and P2 be distance E2. At least one of distances E1 and E2 is greater than or equal to the thickness T of the insulating component 20C. That is, at least one of E1≥T and E2≥T is true.

[0234] Point E is defined as the intersection of a straight line passing through point P1 in the tooth width direction and a straight line passing through point P2 in the axial direction. Point E is located within tooth 12. The distance E1 is the distance from point E to point P1, and the distance E2 is the distance from point E to point P2. The insulating member 20C has a thin-walled portion 20T protruding towards the stepped portion 12S.

[0235] The insulating film 25 has an overlapping portion 25c that overlaps with the inclined surface 206 of the insulating member 20C. When the winding 30 is wound, the overlapping portion 25c of the insulating film 25 is inclined along the inclined surface 206 of the insulating member 20C.

[0236] In this modified example, the starting position of the inclined surface 206 of the insulating member 20C, i.e., point P1, is located at a position where the end face 12e of the non-tooth 12 protrudes axially. Therefore, at least one, more preferably both, of E1≥T and E2≥T are true.

[0237] In this modified example, by reducing the thickness T of the insulating member 20C, the amount of winding 30 used and the copper loss can be reduced in the same way as in embodiment 5. In addition, since the winding bulge of the winding 30 can be reduced, the circumference of the winding 30 can be further shortened, thereby improving the effect of reducing the amount of winding 30 used and the copper loss.

[0238] Furthermore, while a longer inclined surface 206 of the insulating element 20C results in less resin material being used to form the insulating element 20C, excessively long inclined surface 206 makes winding the winding 30 difficult. Therefore, the length of the inclined surface 206 of the insulating element 20C is... Preferably, it is 3mm or less. That is, it preferably meets the following requirements. .

[0239] Preferred range of length for inclined surface 206 This method is not limited to variations of Embodiment 5. It can also be applied to insulating components in Embodiments 1 to 4 and Embodiments 6 to 10 described later, where the curved surface 203 is changed to an inclined surface.

[0240] Implementation method 6.

[0241] Figure 26 This is a cross-sectional view of the stator 1 in embodiment 6, showing the tooth 12, the insulating member 20A, and the insulating film 25, perpendicular to the extending direction of the tooth 12. In embodiment 6, the depth D1 of the step portion 12S located on the first side of the axial direction in the step portion 12S at both ends of the tooth 12 is deeper than the depth D2 of the step portion 12S located on the second side (i.e., D1 > D2).

[0242] exist Figure 26 In the middle, set the top direction to +Z and the bottom direction to -Z. Figure 26 The top (+Z direction) shown is the side where the winding of winding 30 begins, i.e., the first side, and the bottom (-Z direction) is its opposite side, i.e., the second side.

[0243] The side where winding 30 begins is... Figure 22 One side of the starting point of arrow W1 shown in (A), i.e. Figure 22 Above (A). The upper step portion 12S is also called the first step portion, and the lower step portion 12S is also called the second step portion. In addition, the upper (+Z direction) and lower (-Z direction) are not necessarily the same as the upper and lower when the motor 3 is used.

[0244] In tooth 12, the upper step portion 12S has a depth D1 in the axial direction and a width W in the tooth width direction. The lower step portion 12S has a depth D2 in the axial direction and a width W in the tooth width direction. The depths D1 and D2 of the upper and lower step portions 12S satisfy D1 > D2. On the other hand, the width W of the upper and lower step portions 12S is the same.

[0245] The axial length of the gap between the upper stepped portion 12S and the insulating member 20A is defined as the gap length L11. The axial length of the gap between the lower stepped portion 12S and the insulating member 20A is defined as the gap length L12.

[0246] The insulating members 20A located at both axial ends of the tooth 12 are identical in shape and size. The insulating member 20A has a thin-walled portion 20T as described in Embodiment 2.

[0247] The depths D1 and D2 of the upper and lower step sections 12S satisfy D1 > D2, therefore the gap lengths L11 and L12 satisfy L11 > L12.

[0248] The insulating film 25 is fixed to the stator core 10 by winding the winding 30, not by adhesive. On the other hand, both the axial length of the insulating film 25 and the axial length of the stator core 10 have tolerances. Typically, the tolerance of the stator core 10 is larger than that of the insulating film 25.

[0249] Therefore, when the insulating film 25 is fixed to the stator core 10 by winding the winding 30, the insulating film 25 shifts downward relative to the stator core 10 due to gravity. When the insulating film 25 shifts downward, the upper overlap length L0 becomes shorter and the lower overlap length L0 becomes longer.

[0250] In embodiment 6, as described above, the depth D1 of the upper step portion 12S is deeper than the depth D2 of the lower step portion 12S, and thus the upper gap length L11 is longer than the lower gap length L12. Therefore, even if the upper overlap length L0 is shorter, the spatial distance of the upper step portion 12S can be increased, ensuring sufficient insulation between the stator core 10 and the winding 30.

[0251] Here, the insulating component 20A is formed by a forming mold, and the insulating film 25 is cut from a roll of raw material, so the deviation in axial length is small. In contrast, the stator core 10 is assembled by stacking electromagnetic steel plates along the axial direction, so the deviation in axial length is large.

[0252] Let the thickness of the electromagnetic steel plate constituting the stator core 10 be Ts (mm), the number of layers be Ns, and the duty cycle be Fs. The duty cycle Fs is the ratio of the product of the plate thickness Ts and the number of layers Ns in the axial length Ls (mm) of the stator core 10, and is represented by Fs = (Ts × Ns) / Ls.

[0253] When assembling the stator core 10, the number of electromagnetic steel plates Ns is determined based on the target value of the axial length of the stator core 10 and the plate thickness Ts of the electromagnetic steel plate. However, due to the deviation of the duty cycle Fs, the axial length of the stator core 10 also deviates. Correspondingly, the aforementioned insulating film 25 shifts downward.

[0254] The deviation V of the axial length of the stator core 10 is expressed by V = Ts × Ns × (1 - Fs) using the plate thickness Ts, the number of sheets Ns, and the duty cycle Fs. The difference (D1 - D2) between the depths D1 and D2 mentioned above preferably satisfies D1 - D2 < Ts × Ns × (1 - Fs).

[0255] In this way, at least a portion of the reduction in the overlap length L0 of the first side (e.g., above) caused by the displacement of the insulating film 25 can be compensated by the difference in depths D1 and D2, thus ensuring adequate insulation between the stator core 10 and the winding 30.

[0256] Apart from the points mentioned above, the stator of Embodiment 6 is constructed in the same manner as the stator 1 of Embodiment 1. Furthermore, the insulating member 20 of Embodiment 1, the insulating member 20B of Embodiment 5, or the insulating member 20C of the modified example may be provided instead of the insulating member 20A. Additionally, an inclined surface may be provided instead of the curved surface 203 of the insulating member 20.

[0257] As explained above, in embodiment 6, since the depth D1 of the step portion 12S on the first side (e.g., above) and the depth D2 of the step portion 12S on the second side (e.g., below) satisfy D1 > D2, the difference between depths D1 and D2 can compensate for the reduction in the overlap length L0 of the first side caused by the displacement of the insulating film 25 to the second side.

[0258] Furthermore, by ensuring that the depths D1 and D2 of the step portion 12S on the first and second sides satisfy D1-D2<Ts×Ns×(1-Fs), the difference between depths D1 and D2 can compensate for the reduction in the surface distance on the first side caused by the displacement of the insulating film 25 due to the deviation in the axial length of the stator core 10.

[0259] Implementation method 7.

[0260] Figure 27 This is a cross-sectional view showing the stepped portion 12S of the tooth 12F in the stator 1 of Embodiment 7, and the surrounding insulating member 20 and insulating film 25. The tooth 12F of Embodiment 7 has an intermediate stepped portion 12d in the stepped portion 12S.

[0261] like Figure 27 As shown, the intermediate step portion 12d is configured to protrude axially from the bottom surface 12b of the step portion 12S and protrude from the wall surface 12c toward the groove 13 side. The intermediate step portion 12d is formed of an electromagnetic steel plate.

[0262] The intermediate step portion 12d is formed by varying the width of the electromagnetic steel plate constituting the tooth 12F in stages. By forming the intermediate step portion 12d, the width of the tooth 12F can be increased, thereby reducing the magnetic reluctance in the tooth 12F and suppressing the generation of magnetic saturation.

[0263] The stepped portion 12S has a depth D in the axial direction and a width W in the tooth width direction. A gap with a length L1 is provided between the bottom surface 12b of the stepped portion 12S and the insulating member 20.

[0264] Insulating member 20 and insulating member 20 of embodiment 1 ( Figure 7 Similarly, the same configuration is used. The intersection point of the opposing surface 204 of the insulating member 20 facing the step portion 12S and the surface of the insulating film 25 on the tooth 12F side is designated as point P.

[0265] As described in Embodiment 1, the spatial distance is defined by the shorter of the distance from point P to the bottom surface 12b of the step portion 12S (i.e., the width W) and the distance from point P to the wall surface 12c (i.e., the gap length L1).

[0266] If the smaller of the width W of the step portion 12S and the gap length L1 is set as Q, then the intermediate step portion 12d is preferably formed outside a circle (also called a reference circle) with radius Q centered at point P. In this way, the intermediate step portion 12d can be formed without affecting the spatial distance.

[0267] Figure 28 This is a cross-sectional view showing another structural example of the stepped portion 12S of the tooth 12F in Embodiment 7. For example... Figure 28 As shown, an intermediate step portion 12d with multiple steps can also be provided in the step portion 12S of tooth 12F.

[0268] By setting multiple steps in the step section 12S (in) Figure 28 The intermediate step portion 12d (of steps d1 to d4) can further increase the width of the tooth 12F, thus improving the reduction of magnetic reluctance and the suppression of magnetic saturation in the tooth 12F. The number of steps in the intermediate step portion 12d is four in this case, but it can be less than four or more than five.

[0269] exist Figure 27 , 28 The example shown is that the depth D, width W, and gap length L1 of the step portion 12S are the same, but it is also possible that one of the depth D, width W, and length L1 is different from the others, or all three are different.

[0270] Apart from the points mentioned above, the stator of Embodiment 7 is constructed in the same manner as the stator 1 of Embodiment 1. The insulating member 20A of Embodiment 2, the insulating member 20B of Embodiment 5, or the insulating member 20C of the modified example may be provided instead of the insulating member 20. Furthermore, the insulating film 25 may be provided as described in Embodiments 3 and 4. Additionally, an inclined surface may be provided instead of the curved surface 203 of the insulating member 20.

[0271] As explained above, in embodiment 7, an intermediate step portion 12d is formed in the step portion 12S of tooth 12F. Therefore, the magnetic resistance in tooth 12F can be reduced and the generation of magnetic saturation can be suppressed, thereby suppressing the increase of iron loss and copper loss.

[0272] Furthermore, if the smaller of the width W of the step portion 12S and the gap length L1 is set as Q, the intermediate step portion 12d is formed outside the circle with radius Q centered at point P, thus the intermediate step portion 12d can be formed without affecting the spatial distance.

[0273] Implementation method 8.

[0274] Figure 29 This is a cross-sectional view of the stator 1 in embodiment 8, showing the tooth 12, the insulating member 40, and the insulating film 26, perpendicular to the extending direction of the tooth 12. In embodiment 8, the insulating member 40 has a recess 41 into which a portion of the insulating film 26 is inserted.

[0275] like Figure 29 As shown, the insulating member 40 has a recess 41 on the side opposite to the end face 12e of the tooth 12. The recess 41 of the insulating member 40 is axially opposed to a portion of the stepped portion 12S of the tooth 12.

[0276] Figure 30 This is a cross-sectional view showing the stepped portion 12S of the tooth 12 and the surrounding insulating member 40 and insulating film 25. The recess 41 of the insulating member 40 has a recess bottom surface 41b opposite to the end face 12e of the tooth 12, a recess inner surface 41a located on the groove 13 side of the recess bottom surface 41b, and a recess inner surface 41c opposite to the recess inner surface 41a.

[0277] The inner surface 41a of the recess is located in the tooth width direction at a position that protrudes towards the groove 13 from the wall surface 12c of the stepped portion 12S. On the other hand, the inner surface 41c of the recess is located on the end face 12e of the tooth 12.

[0278] The insulating member 40 also has: a top surface 401, which faces in the axial direction opposite to the end face 12e of the tooth 12; a side surface 402, which faces the groove 13; and a curved surface 403, which extends from the top surface 401 to the side surface 402. The top surface 401 is also referred to as the first surface, the side surface 402 as the second surface, and the curved surface 403 as the third surface.

[0279] The axial depth Lc of the recess 41 of the insulating member 40 is the distance from the end face 12e of the tooth 12 to the bottom surface 41b of the recess. The distance from the side face 402 of the insulating member 40 to the recess 41 is defined as La. The portion of the bottom surface of the insulating member 40 located between the side face 402 of the insulating member 40 and the inner surface 41a of the recess 41 is defined as the opposing surface 405. The opposing surface 405 of the insulating member 40 faces the stepped portion 12S of the tooth 12. The length of the opposing surface 405 in the tooth width direction is the aforementioned distance La.

[0280] The insulating film 26 is provided in such a way that it covers the side surface 12a of the tooth 12. The insulating film 26 also has an insertion portion 26a that inserts into the recess 41 via the stepped portion 12S of the tooth 12. The insertion portion 26a is inclined relative to the axial direction and extends in a straight line.

[0281] The insulation distance between the stator core 10 and the winding 30 is the sum of the distance La from the side 402 of the insulating member 40 to the recess 41, the length Lb of the portion of the insertion part 26a located in the recess 41, and the axial depth Lc of the recess 41.

[0282] In this way, the insertion portion 26a of the insulating film 26 is inserted into the recess 41 of the insulating member 40 via the stepped portion 12S of the tooth 12, so the insulation distance can be ensured by the above-mentioned La+Lb+Lc, thus ensuring the insulation between the stator core 10 and the winding 30.

[0283] In addition, since the recess 41 is formed inside the insulating member 40, the size and shape of the recess 41 do not affect the winding state of the winding 30, so the insulation distance is easy to adjust.

[0284] The insulating member 40 is constructed in the same manner as the insulating member 20 of Embodiment 1, except that it has the recess 41. The insulating film 26 is constructed in the same manner as the insulating film 25 of Embodiment 1, except that it has the insertion portion 26a.

[0285] Apart from the points mentioned above, the stator of Embodiment 8 is constructed in the same manner as the stator 1 of Embodiment 1. Furthermore, the insulating member 40 may also be provided in the thin-walled portion 20T described in Embodiment 2. Alternatively, an inclined surface may be provided instead of the curved surface 403 of the insulating member 40.

[0286] As explained above, in embodiment 8, the insulating member 40 has a recess 41 that is axially opposed to at least a portion of the stepped portion 12S of the tooth 12, and the insertion portion 26a of the insulating film 26 is inserted into the recess 41 via the stepped portion 12S. Therefore, by the distance La from the side surface 402 of the insulating member 40 to the recess 41 and the length Lb of the insertion portion 26a within the recess 41, the insulation distance can be extended. As a result, sufficient insulation between the stator core 10 and the winding 30 can be ensured.

[0287] Implementation method 9.

[0288] Figure 31 This is a cross-sectional view of the stator 1 in embodiment 9, showing the tooth 12, the insulating member 40A, and the insulating film 27, perpendicular to the extending direction of the tooth 12. In embodiment 9, the thin-walled portion 40T formed in the insulating member 40A is configured to guide a portion of the insulating film 27.

[0289] like Figure 31 As shown, the insulating member 40A has a recess 41 on the side opposite to the end face 12e of the tooth 12. The recess 41 of the insulating member 40A is axially opposed to a portion of the stepped portion 12S of the tooth 12.

[0290] Figure 32This is a cross-sectional view showing the stepped portion 12S of tooth 12 and the surrounding insulating member 40A and insulating film 27. The recess 41 of the insulating member 40A is the same as the recess 41 of the insulating member 40 in Embodiment 8. Figure 30 Similarly, it has an inner surface 41a, a bottom surface 41b, and an inner surface 41c of the recess. The axial depth Lf of the recess 41 is the distance from the end face 12e of the tooth 12 to the bottom surface 41b of the recess.

[0291] The portion between the recess 41 and the side surface 402 of the insulating member 40A is referred to as the thin-walled portion 40T. The thin-walled portion 40T has a width Ld in the tooth width direction. The thin-walled portion 40T is also called the guide portion.

[0292] A portion of the thin-walled portion 40T faces the wall surface 12c of the stepped portion 12S. A gap is formed between the thin-walled portion 40T and the wall surface 12c of the stepped portion 12S, through which the insulating film 27 can be inserted.

[0293] The insulating film 27 is provided in such a way that it covers the side surface 12a of the tooth 12. The insulating film 27 also has an insertion portion 27a that is inserted into the recess 41 of the insulating member 40A via the stepped portion 12S of the tooth 12.

[0294] The insertion portion 27a of the insulating film 27 is guided by the thin-walled portion 40T of the insulating member 40A and the wall surface 12c of the stepped portion 12S, and extends axially. The portion of the insertion portion 27a that is guided by the thin-walled portion 40T and extends axially is designated as the first portion S1.

[0295] The portion of the insertion portion 27a of the insulating member 40A that does not reach the thin-walled portion 40T extends obliquely relative to the axial direction. This obliquely extending portion of the insertion portion 27a is designated as the second portion S2. That is, the insertion portion 27a of the insulating member 40A has a curved shape.

[0296] The insulation distance between the stator core 10 and the winding 30 is the sum of the width Ld of the thin-walled portion 40T of the insulating member 40A, the length Le of the first part S1 of the insertion portion 27a of the insulating film 27, and the axial depth Lf of the recess 41.

[0297] The insulating member 40A is constructed in the same manner as the insulating member 20 of Embodiment 1, except that it has a recess 41 and a thin-walled portion 40T. The insulating film 27 is constructed in the same manner as the insulating film 25 of Embodiment 1, except that it has an insertion portion 27a.

[0298] The insulating film 27 is formed from resins such as PET and has sufficient strength to ensure reliability. Therefore, a processing step is required to bend the insulating film 27 to the desired angle.

[0299] In Embodiment 9, the insertion portion 27a of the insulating film 27 is guided into the recess 41 by the thin-walled portion 40T of the insulating member 40A. Therefore, the tilt angle of the insertion portion 27a is smaller than that of the insertion portion 26a in Embodiment 8. This reduces the amount of bending of the insulating film 27. Furthermore, it simplifies the insertion process of the insulating film 27.

[0300] Apart from the points mentioned above, the stator of Embodiment 9 is constructed in the same manner as the stator 1 of Embodiment 1. Furthermore, the thin-walled portion 40T of the insulating member 40A may not protrude towards the stepped portion 12S. Alternatively, an inclined surface may be provided instead of the curved surface 403 of the insulating member 40A.

[0301] As explained above, in embodiment 9, the insulating member 40A has a recess 41 opposite to a portion of the stepped portion 12S of the tooth 12, and a thin-walled portion 40T is provided on the groove 13 side of the recess 41. The insertion portion 27a of the insulating film 27 is guided into the recess 41 by the thin-walled portion 40T. Therefore, the amount of bending of the insulating film 27 can be reduced, and sufficient insulation between the stator core 10 and the winding 30 can be ensured.

[0302] Implementation method 10.

[0303] Figure 33 This is a cross-sectional view showing the stepped portion 12S of the tooth 12 in the stator 1 of Embodiment 10, the surrounding insulating member 40B, and the insulating film 26. In Embodiment 10, the thin-walled portion 40T of the insulating member 40B is inclined.

[0304] like Figure 33 As shown, the insulating member 40B has a recess 42 on the side opposite to the end face 12e of the tooth 12. The recess 42 of the insulating member 40B is axially opposed to a portion of the stepped portion 12S of the tooth 12.

[0305] The recess 42 of the insulating member 40B and the recess 41 of the insulating member 40A in embodiment 9 ( Figure 32 Similarly, it has a recessed inner surface 42a, a recessed bottom surface 42b, and a recessed inner surface 42c.

[0306] The portion between the recess 42 and the side surface 402 of the insulating member 40B is referred to as the thin-walled portion 40T. The end portion on the stepped portion 12S side of the thin-walled portion 40T is designated as the end portion U.

[0307] The thin-walled portion 40T of the insulating member 40B faces the wall surface 12c of the stepped portion 12S of the tooth 12. A gap is formed between the thin-walled portion 40T and the wall surface 12c of the stepped portion 12S, through which the insulating film 26 can be inserted.

[0308] The inner surface of the thin-walled portion 40T is the inner surface 42a of the recess 42. The width of the thin-walled portion 40T is defined by the distance between the side surface 402 of the insulating member 40B and the inner surface 42a of the recess. The inner surface 42a of the recess slopes in such a way that the width of the thin-walled portion 40T becomes narrower as it approaches the end portion U.

[0309] The insulating film 26 is provided in such a way that it covers the side surface 12a of the tooth 12. The insulating film 26 also has an insertion portion 26a that is inserted into the recess 42 via the stepped portion 12S of the tooth 12. The insertion portion 26a is guided into the recess 42 along the inner surface of the thin-walled portion 40T of the insulating member 40B (i.e., the inner surface 42a of the recess).

[0310] The insulating member 40B is constructed in the same manner as the insulating member 20 of Embodiment 1, except that it has the recess 42 and the thin-walled portion 40T. The insulating film 26 is constructed in the same manner as the insulating film 25 of Embodiment 1, except that it has the insertion portion 26a.

[0311] When the insulating part 40B is formed by resin injection molding, the thin-walled portion 40T corresponds to the portion where resin is last filled into the mold. By having a shape where the width of the thin-walled portion 40T narrows towards the end portion U, as described above, moldability can be improved. Furthermore, the insertion of the insulating film 26 into the recess 24 becomes easier, thus simplifying the manufacturing process.

[0312] Apart from the points mentioned above, the stator of Embodiment 10 is constructed in the same manner as the stator 1 of Embodiment 1. Furthermore, an inclined surface may be provided instead of the curved surface 403 of the insulating member 40B.

[0313] As explained above, in embodiment 10, the insulating member 40B has a recess 41 opposite to at least a portion of the stepped portion 12S of the tooth 12, and a thin-walled portion 40T is provided on the groove 13 side of the recess 41. The thin-walled portion 40T has an inclination with its width decreasing towards the end portion U. Therefore, the formability of the insulating member 40B can be improved, and the insulating film 26 can be easily inserted.

[0314] Figure 34 This is a cross-sectional view showing another structural example of the insulating member 40B in Embodiment 10. Figure 34 In the structural example shown, the insulating element 40B protrudes from the side 12a of the tooth 12 toward the groove 13.

[0315] like Figure 34 As shown, in embodiment 10, the side surface 402 of the insulating member 40B extends from the side surface 12a of the tooth 12 towards the groove 13 side ( Figure 34 (Right side) protrudes. The amount of protrusion of the side 402 of the insulating member 40B from the side 12a of the tooth 12 toward the groove 13 is defined as the protrusion amount G.

[0316] The insulating film 26 is inserted into the recess 42 inside the insulating member 40B, and is therefore not disposed on the outside of the insulating member 40B. Therefore, if the side 12a of the insulating member 40B protrudes towards the slot 13 side from the tooth 12, and its protrusion amount G is close to the thickness F of the insulating film 26, the winding 30 can be performed smoothly.

[0317] The thickness F of the insulating film 26 is 0.1 mm to 0.3 mm. Therefore, the protrusion G of the insulating member 40B protruding from the side 12a of the tooth 12 preferably satisfies 0.1 mm ≤ G ≤ 0.3 mm.

[0318] Figure 35 This is a cross-sectional view showing another structural example of the insulating member 40B in embodiment 10. Figure 35 In the structural example shown, the insulating member 40B protrudes from the side 12a of the tooth 12 by an amount exceeding the thickness F of the insulating film 26.

[0319] As described in Embodiment 1, a winding bulge H1 is generated between the winding 30 and the insulating film 26. Therefore, if the protrusion G of the insulating member 40B protruding from the side 12a of the tooth 12 is close to the sum of the thickness F of the insulating film 26 and the amount of the winding bulge, the winding 30 can be wound more smoothly.

[0320] The thickness F of the insulating film 26 is 0.1 mm to 0.3 mm, and the amount of bulging during winding is typically 0.2 mm. Therefore, the amount of protrusion G of the insulating element 40B protruding from the side 12a of the tooth 12 preferably satisfies 0.3 mm ≤ G ≤ 0.5 mm.

[0321] Figure 34 , 35 The structural example is based on the structure of implementation method 8 ( Figure 29 , 30 However, it can also be applied to implementation methods 9 and 10.

[0322] The features described in embodiments 1 to 10 and their variations can be combined. For example, the structure in which the depth D of the step portion 12S is different at both ends of the tooth 12 in the axial direction, as in embodiment 6, can also be applied to embodiments 1 to 5, 7 to 10.

[0323] <Compressor>

[0324] Next, the compressor 8, which uses the electric motors of embodiments 1 to 10 and their variations, will be described. Figure 36 This is a cross-sectional view showing the structure of compressor 8. Compressor 8 here is a rotary compressor, having a sealed container 80, a compression mechanism 9 disposed within the sealed container 80, an electric motor 3 driving the compression mechanism 9, and a shaft 90 connecting the electric motor 3 and the compression mechanism 9 in a manner capable of transmitting power. Shaft 90 is... Figure 1The shaft 90 shown is connected to the center hole 53 of the rotor 5 of the motor 3. Figure 1 ) Inlay.

[0325] The sealed container 80, for example, is a sealed container formed of steel plate, covering the electric motor 3 and the compression mechanism 9. The sealed container 80 has an upper frame 82 and a frame 81 as a lower frame. The upper frame 82 is equipped with glass terminals 83 as terminals for supplying power to the electric motor 3 and a discharge pipe 85 for discharging the refrigerant compressed within the compressor 8 to the outside. The electric motor 3 and the compression mechanism 9 are housed within the frame 81.

[0326] The compression mechanism 9 has an annular first cylinder 91 and a second cylinder 92 along the shaft 90. The first cylinder 91 and the second cylinder 92 are fixed to the inner side of the frame 81. An annular first piston 93 is disposed on the inner circumference of the first cylinder 91, and an annular second piston 94 is disposed on the inner circumference of the second cylinder 92. The first piston 93 and the second piston 94 are rotary pistons that rotate together with the shaft 90.

[0327] A partition plate 97 is provided between the first cylinder 91 and the second cylinder 92. The partition plate 97 is a circular plate-shaped component with a through hole in the center. Blades (not shown) are provided in the cylinder chambers of the first cylinder 91 and the second cylinder 92 to divide the cylinder chambers into an intake side and a compression side. The first cylinder 91, the second cylinder 92 and the partition plate 97 are fixed together by bolts 98.

[0328] An upper frame 95 is disposed above the first cylinder 91 to block the upper side of the cylinder chamber of the first cylinder 91. A lower frame 96 is disposed below the second cylinder 92 to block the lower side of the cylinder chamber of the second cylinder 92. The upper frame 95 and the lower frame 96 support the shaft 90 so that it can rotate.

[0329] At the bottom of the frame 81 of the sealed container 80, there is refrigeration oil (not shown) that lubricates the sliding parts of the compression mechanism 9. The refrigeration oil rises in a hole 90a formed axially inside the shaft 90 and is supplied to the sliding parts from oil supply holes 90b formed at multiple locations on the shaft 90.

[0330] The stator 1 of the motor 3 is mounted to the inside of the frame 81 via thermoforming. Power is supplied to the windings 30 of the stator 1 from the glass terminals 83 mounted on the upper frame 82. In the center hole 53 of the rotor 5 ( Figure 1 A fixed shaft is 90.

[0331] A receiver 87 for storing refrigerant gas is installed on the frame 81. The receiver 87 is held, for example, by a retainer 86 located on the outside of the frame 81. A pair of suction pipes 88, 89 are installed on the frame 81, through which refrigerant gas is supplied from the receiver 87 to cylinders 91, 92.

[0332] As a refrigerant, refrigerants such as R410A, R407C, or R22 can be used, but from the perspective of preventing global warming, refrigerants with low GWP (Global Warming Potential) are preferred. Examples of refrigerants with low GWP include the following.

[0333] (1) First, haloalkanes with carbon-carbon double bonds in their composition can be used, such as HFO (Hydro-Fluoro-Orefin)-1234yf (CF3CF=CH2). The GWP of HFO-1234yf is 4.

[0334] (2) Alternatively, hydrocarbons with carbon-carbon double bonds in their composition can be used, such as R1270 (propylene). R1270 has a GWP of 3, which is lower than HFO-1234yf, but its flammability is higher than that of HFO-1234yf.

[0335] (3) Alternatively, a mixture containing at least one of a halogenated hydrocarbon having a carbon-carbon double bond in its composition and a hydrocarbon having a carbon-carbon double bond in its composition may be used, such as a mixture of HFO-1234yf and R32. HFO-1234yf is a low-pressure refrigerant, and therefore tends to have a large pressure drop, which may lead to a decrease in the performance of the refrigeration cycle (especially the evaporator). Therefore, in practice, it is preferable to use a mixture with R32 or R41, which are refrigerants with a higher pressure than HFO-1234yf.

[0336] The basic operation of compressor 8 is as follows. Refrigerant gas supplied from receiver 87 is supplied to the respective cylinder chambers of first cylinder 91 and second cylinder 92 through suction pipes 88 and 89. When motor 3 is driven and rotor 5 rotates, shaft 90 rotates together with rotor 5. Furthermore, first piston 93 and second piston 94, which are engaged with shaft 90, rotate eccentrically within each cylinder chamber, compressing the refrigerant within each chamber. The compressed refrigerant passes through slot 18 of stator 1 (… Figure 1 ) and the through holes 57 and 58 of rotor 5 Figure 2 It rises within the sealed container 80 and is discharged to the outside through the discharge pipe 85.

[0337] Furthermore, the compressor using electric motor 3 is not limited to a rotary compressor; for example, it can also be a scroll compressor.

[0338] The electric motor 3, equipped with the stator described in the various embodiments and modifications, achieves high motor efficiency by reducing iron and copper losses in the gears 12. Therefore, the operating efficiency of the compressor 8 can be improved.

[0339] Refrigeration Cycle Device

[0340] Next, for those with Figure 36The refrigeration cycle device 300 of the compressor 8 shown will be described. Figure 37 This is a diagram showing a refrigeration cycle device 300. The refrigeration cycle device 300 is, for example, an air conditioning unit, but is not limited to this; it could also be, for example, a refrigerator.

[0341] Figure 37 The refrigeration cycle unit 300 shown includes a compressor 301, a condenser 302 for condensing refrigerant, a pressure reducing device 303 for reducing refrigerant pressure, and an evaporator 304 for evaporating refrigerant. The compressor 301, condenser 302, and pressure reducing device 303 are located in the outdoor unit 310, and the evaporator 304 is located in the indoor unit 320.

[0342] Compressor 301, condenser 302, pressure reducing device 303, and evaporator 304 are connected via refrigerant piping 307, forming a refrigerant circuit. Compressor 301 consists of... Figure 36 The compressor 8 shown is configured. The refrigeration cycle unit 300 also includes an outdoor fan 305 opposite to the condenser 302 and an indoor fan 306 opposite to the evaporator 304.

[0343] The refrigeration cycle unit 300 operates as follows: The compressor 301 compresses the intake refrigerant and delivers it as a high-temperature, high-pressure refrigerant gas. The condenser 302 performs heat exchange between the refrigerant from the compressor 301 and the outdoor air supplied by the outdoor fan 305, condensing the refrigerant and delivering it as a liquid refrigerant. The pressure reducing device 303 expands the liquid refrigerant from the condenser 302, delivering it as a low-temperature, low-pressure liquid refrigerant.

[0344] The evaporator 304 performs heat exchange between the low-temperature, low-pressure liquid refrigerant supplied from the pressure reducing device 303 and the indoor air, causing the refrigerant to evaporate and be released as refrigerant gas. The heated air obtained by the evaporator 304 is supplied to the room through the indoor fan 306.

[0345] In the compressor 301 of the refrigeration cycle device 300, an electric motor 3 equipped with a stator 1 as described in various embodiments and modifications can be used, thereby improving the operating efficiency and reliability of the refrigeration cycle device 300.

[0346] The preferred embodiments have been described in detail above, but this disclosure is not limited to the above embodiments and various improvements or modifications can be made.

[0347] Label Explanation

[0348] 1: Stator; 3: Motor; 5: Rotor; 8: Compressor; 9: Compression mechanism; 10: Stator core; 11: Back of core; 12: Tooth; 12S: Stepped section; 12a: Side; 12b: Bottom; 12c: Wall; 12d: Middle stepped section; 12e: End face; 13: Slot; 14: Segmented core; 20: Insulator; 20T: Thin-walled section; 25: Insulating film; 25a: Overlapping section; 25b: Entering section; 25c: Overlapping section; 26, 27: Insulating film; 26a, 27a: Insertion section; 30: Winding; 40, 40A, 40B: Insulator; 40T: Thin-walled section; 41, 42 : Recess; 50: Rotor core; 51: Magnet insertion hole; 55: Permanent magnet; 80: Sealed container; Frame; 201: Top surface (first surface); 202: Side surface (second surface); 203: Curved surface (third surface); 204, 205: Opposing surfaces; 206: Inclined surface (third surface); 301: Compressor; 302: Condenser; 303: Pressure reducing device; 304: Evaporator; 401: Top surface (first surface); 402: Side surface (second surface); 403: Curved surface (third surface); 405: Opposing surface; D: Depth of step; L1: Gap length; P: Contact point; W: Width of step.

Claims

1. A stator having: A stator core having an annular core back, teeth extending radially inward from the core back, and slots adjacent to the teeth in the circumferential direction; An insulating portion is disposed on the tooth; and The winding, which is wound around the teeth with the insulation portion in between, The tooth has an axial end face facing the stator core, a side face facing the slot, and a stepped portion formed between the end face and the side face. The insulating portion includes: an insulating member covering the end face of the tooth; and an insulating film covering the side face of the tooth and a portion of the insulating member. When the direction perpendicular to both the extension direction and the axial direction of the tooth is defined as the tooth width direction, the stepped portion has a depth D in the axial direction and a width W in the tooth width direction. A gap is provided along the axial direction between the stepped portion of the tooth and the insulating member. The sum of the shortest distance from the contact point between the insulating element's surface facing the stepped portion and the insulating film to the stepped portion, and the overlap length L0, is greater than or equal to the insulation distance required for the insulation between the stator core and the winding. The overlap length L0 is the length by which the insulating film overlaps with the insulating element. At least one of 0 < D ≤ 1.25 mm and 0 < W ≤ 1.25 mm is true.

2. The stator according to claim 1, wherein, The axial length of the gap, i.e., the gap length L1, satisfies 0 < L1 ≤ D.

3. The stator according to claim 1 or 2, wherein, The axial length of the gap, i.e., the gap length L1, and the width W of the step portion satisfy L1≤W.

4. The stator according to any one of claims 1 to 3, wherein, The insulating member has a thin-walled portion that protrudes from the end face of the tooth toward the stepped portion, and the insulating film also overlaps with the thin-walled portion.

5. The stator according to any one of claims 1 to 4, wherein, The depth D and the width W of the stepped portion satisfy W≤D.

6. The stator according to any one of claims 1 to 5, wherein, The width W of the step portion satisfies 0.3mm ≤ W ≤ 1.25mm.

7. The stator according to any one of claims 1 to 6, wherein, A portion of the insulating film enters the stepped portion of the tooth.

8. The stator according to any one of claims 1 to 7, wherein, The insulating member has: a first surface facing the end face of the tooth; The second surface faces the groove; and the third surface is a curved or inclined surface extending between the first and second surfaces.

9. The stator according to claim 8, wherein, When the boundary between the third surface and the second surface is set as point P1, and the boundary between the third surface and the first surface is set as point P2, The length L2 of the portion of the insulating film that protrudes beyond point P1 is less than half the distance from point P1 to point P2 along the third surface.

10. The stator according to claim 8 or 9, wherein, The third surface of the insulating element is a curved surface. When the distance between the first surface of the insulating member and the end face of the tooth is set to T, and the radius of curvature of the curved surface is set to R, R≥T holds true.

11. The stator according to claim 8 or 9, wherein, The third surface of the insulating element is an inclined surface. When the distance between the first surface of the insulating member and the end face of the tooth is defined as T, the inflection point between the third surface and the second surface is defined as point P1, the inflection point between the third surface and the first surface is defined as point P2, the distance between point P1 and point P2 in the tooth width direction is defined as E1, and the distance between point P1 and point P2 in the axial direction is defined as E2, At least one of T≤E1 and T≤E2 is true.

12. The stator according to any one of claims 8 to 10, wherein, The third surface of the insulating element is a curved surface. The radius of curvature R of the curved surface satisfies R≤3mm.

13. The stator according to claim 8, 9 or 11, wherein, The third surface of the insulating element is an inclined surface. When the inflection point between the third surface and the second surface is designated as point P1, the inflection point between the third surface and the first surface is designated as point P2, the distance between point P1 and point P2 in the tooth width direction is designated as E1, and the distance between point P1 and point P2 in the axial direction is designated as E2, Established.

14. The stator according to any one of claims 1 to 13, wherein, When the coefficient of thermal expansion of the insulating film is set as α, the axial length of the insulating film at 20°C is set as Li, and the upper limit of the allowable temperature range of the stator is set as Tmax, The width W of the step portion satisfies W≥Li×α×(Tmax-20) / 2.

15. The stator according to any one of claims 1 to 14, wherein, The tooth has a first stepped portion on the first side of the axial direction, which serves as the stepped portion. The tooth has a second stepped portion on the second side of the axial direction. The axial depth D1 of the first step portion and the axial depth D2 of the second step portion satisfy D1 > D2.

16. The stator according to claim 15, wherein, When the thickness of the electromagnetic steel plate constituting the stator core is set to Ts, the number of layers of the electromagnetic steel plate is set to Ns, and the duty cycle is set to Fs, The condition D1-D2 < Ts×Ns×(1-Fs) holds true.

17. The stator according to any one of claims 1 to 16, wherein, The tooth has a middle stepped portion in the stepped portion. When a reference circle is defined with the point where the surface of the insulating member facing the step portion contacts the insulating film as the center, and with the shorter of the axial length of the gap (i.e., the gap length L1) and the width W of the step portion as the radius, the reference circle is defined. The intermediate stepped portion is positioned outside the reference circle.

18. The stator according to any one of claims 1 to 17, wherein, The insulating member has at least a portion of a recess that opposes the stepped portion of the tooth. A portion of the insulating film is inserted into the recess of the insulating member via the stepped portion of the tooth.

19. The stator according to claim 18, wherein, The insulating member has a thin-walled portion that protrudes from the end face of the tooth toward the stepped portion. The insulating film is guided by the thin-walled portion and inserted into the recess.

20. The stator according to claim 19, wherein, The thin-walled portion has an end portion that protrudes most towards the stepped portion side. The width of the thin-walled portion in the tooth width direction decreases as it approaches the end portion.

21. The stator according to any one of claims 1 to 20, wherein, The insulating element protrudes into the groove from the side of the tooth.

22. The stator according to claim 21, wherein, The protrusion G of the insulating member relative to the side of the tooth satisfies 0.1mm ≤ G ≤ 0.3mm.

23. The stator according to claim 21, wherein, The protrusion G of the insulating member relative to the side of the tooth satisfies 0.3mm ≤ G ≤ 0.5mm.

24. A stator having: A stator core having an annular core back, teeth extending radially inward from the core back, and slots adjacent to the teeth in the circumferential direction; An insulating portion is disposed on the tooth; and The winding, which is wound around the teeth with the insulation portion in between, The tooth has an axial end face facing the stator core, a side face facing the slot, and a stepped portion formed between the end face and the side face. The insulating portion has an insulating member covering the end face of the tooth and an insulating film covering the side face of the tooth. The insulating member has at least a portion of a recess that opposes the stepped portion of the tooth. A portion of the insulating film is inserted into the recess of the insulating member via the stepped portion of the tooth.

25. An electric motor, comprising: The stator according to any one of claims 1 to 24; and The rotor is located inside the stator.

26. A compressor comprising: The electric motor according to claim 25; and The compression mechanism is driven by the electric motor.

27. A refrigeration cycle apparatus comprising the compressor, condenser, pressure reducing device, and evaporator as described in claim 26.

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