Electric motor manufacturing method and electric motor

Abstract

To avoid an increase in manufacturing cost of a motor and improve the reliability of a conductor wound in a first layer of a winding portion.SOLUTION: A method for manufacturing an electric motor that includes a stator core having an annular yoke portion and a teeth portion extending radially from the yoke portion, an insulator having a winding drum attached to the teeth portion, and a winding portion having a plurality of layers formed by winding wire around the winding drum and teeth portion, comprises: winding, when a winding pitch of the wire wound in line radially of the yoke portion is P and an outer diameter of the wire is B, the wire radially in a first layer of the winding portion such that P≥B is satisfied; and winding the wire in at least one layer from the second layer onwards of the winding portion such that P<B is satisfied.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing an electric motor and to an electric motor. [Background technology]

[0002] A known electric motor includes a stator core and an insulator provided at an end of the stator core, and a winding portion having multiple layers formed by winding a conductor in a concentrated manner around the teeth of the stator core and the winding drum of the insulator. In this type of electric motor, miniaturization and high efficiency are achieved by increasing the space factor of the conductor in the winding portion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2015 / 063877 [Patent Document 2] Japanese Patent Publication No. 2020-127255 [Patent Document 3] Japanese Patent Application Publication No. 2018-85870 Summary of the Invention [Problem to be solved by the invention]

[0004] In the electric motor described in Patent Document 1, the surface of the winding drum of the insulator is formed flat along the radial direction of the stator core. The winding portion includes a first layer formed by winding a conductor along the surface of the winding drum from one end side (outer diameter side) to the other end side (inner diameter side) in the radial direction of the stator core, and a second layer stacked on top of the first layer and formed by winding a conductor from the other end side (inner diameter side) to one end side (outer diameter side) in the radial direction of the stator core.

[0005] In such an electric motor, if the winding pitch (the amount of movement per turn of the nozzle in the winding process using a winding machine) of the first layer of conductor wires wound side by side in the radial direction of the stator core is reduced in order to increase the space factor of the winding, part of the later wound wire may ride up on the earlier wound wire when forming the first layer of the winding. In this case, the later wound wire may not be lined up with the other end (inner diameter side) of the earlier wound winding, but may intrude on one end (outer diameter side) of the earlier wound winding, and because the surface of the insulating film of the conductor wire is slippery, the earlier wound wire may be pushed out to the other end (inner diameter side) of the stator core (hereinafter referred to as "winding irregularity"). When winding irregularities occur, the conductor that makes up the winding, which is pulled so that it is pushed to the end on the inner diameter side, may break, or the cross-sectional area of ​​the pulled conductor may decrease, increasing electrical resistance and the amount of heat generated by the conductor. In other words, the reliability of the conductor wound in the first layer of the winding may decrease. Note that this phenomenon is not limited to when the first layer of the winding is wound from the outer diameter side to the inner diameter side in the radial direction of the stator core, but can also occur when the first layer of the winding is wound from the inner diameter side to the outer diameter side in the radial direction of the stator core.

[0006] Meanwhile, there is a structure in which grooves or the like are provided on the winding drum of the insulator to prevent slippage of the conductor wound in the first layer of the winding section (Patent Document 2, Patent Document 3). However, in this structure, grooves or the like that match the outer diameter of the conductor are provided on the winding drum, so it is necessary to change the insulator depending on the outer diameter of the conductor, which increases the manufacturing cost of the motor.

[0007] The disclosed technology has been made in consideration of the above, and aims to provide a method for manufacturing an electric motor and an electric motor that can avoid an increase in the manufacturing cost of the electric motor and can improve the reliability of the conductor wound in the first layer of the winding section. [Means for solving the problem]

[0008] One aspect of the method for manufacturing an electric motor disclosed in the present application is a method for manufacturing an electric motor including a stator core having an annular yoke portion and teeth portions extending radially from the yoke portion, an insulator having a winding drum portion attached to the teeth portions, and a winding portion having multiple layers formed by windings of wire around the winding drum portion and the teeth portions, in which, when the winding pitch of the wire wound in a radially aligned manner is P and the outer diameter of the wire is B, the wire is wound radially in the first layer of the winding portion so as to satisfy P>B, and the wire is wound in at least one layer from the second layer onwards of the winding portion so as to satisfy P≦B. [Effects of the Invention]

[0009] According to one aspect of the method for manufacturing an electric motor disclosed in the present application, it is possible to avoid an increase in the manufacturing cost of the electric motor and to improve the reliability of the conductor wound in the first layer of the winding portion. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a vertical cross-sectional view showing a compressor equipped with an electric motor according to an embodiment. [Figure 2] FIG. 2 is a bottom view showing the stator core in the embodiment. [Figure 3] FIG. 3 is a perspective view schematically showing an insulator according to the embodiment. [Figure 4] FIG. 4 is a bottom view showing the stator in the embodiment. [Figure 5] FIG. 5 is a cross-sectional view showing a schematic view of a winding portion in the electric motor of the embodiment. [Figure 6] FIG. 6 is a cross-sectional view that schematically shows a winding portion in an electric motor of a comparative example. [Figure 7] FIG. 7 is a cross-sectional view for explaining a case where the first layer of winding is normally wound in the winding step of the comparative example. [Figure 8] FIG. 8 is a cross-sectional view illustrating a case where the winding position of the first layer of the winding is shifted in the winding process of the comparative example. [Figure 9]FIG. 9 is a side view illustrating a case where the winding position of the first layer of the winding is shifted in the winding process of the comparative example. [Figure 10] FIG. 10 is a flowchart for explaining the winding step in the manufacturing method of the electric motor of the embodiment. [Figure 11] FIG. 11 is a cross-sectional view for explaining a case where the first layer of winding is normally wound in the winding step of the embodiment. [Figure 12] FIG. 12 is a cross-sectional view illustrating a case where the winding position of the first layer of the winding is shifted in the winding process of the embodiment. [Figure 13] FIG. 13 is a cross-sectional view showing the state of windings in the winding step of the first modification. [Figure 14] FIG. 14 is a cross-sectional view showing the state of windings in the winding step of the second modification. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, examples of the manufacturing method of an electric motor and the electric motor disclosed in the present application will be described in detail with reference to the drawings. Note that the manufacturing method of an electric motor and the electric motor disclosed in the present application are not limited to the following examples. [Example]

[0012] (Compressor) FIG. 1 is a longitudinal cross-sectional view of a compressor including an electric motor according to an embodiment. As shown in FIG. 1, compressor 1 is a so-called rotary compressor and includes a container 2, a shaft 3, a compression unit 5, and an electric motor 6. The container 2 is made of a metal material and defines a sealed internal space 7. The internal space 7 is generally cylindrical. When the container 2 is placed upright on a horizontal surface, the central axis of the internal space 7 is parallel to the vertical direction. The container 2 defines an oil reservoir 8 below the internal space 7. The oil reservoir 8 stores lubricating oil for lubricating the compression unit 5. The container 2 is connected to a suction pipe 11 for drawing in refrigerant and a discharge pipe 12 for discharging compressed refrigerant. The shaft 3 is disposed vertically within the internal space 7 of the container 2, with one end immersed in the oil reservoir 8. The shaft 3 is supported by the container 2 so as to be rotatable about the central axis of the internal space 7. The shaft 3 rotates to supply the lubricating oil stored in the oil reservoir 8 to the compression section 5 .

[0013] The compression section 5 is disposed at the bottom of the internal space 7 and above the oil sump 8. The compressor 1 further includes an upper muffler cover 14 and a lower muffler cover 15. The upper muffler cover 14 is disposed above the compression section 5 in the internal space 7. The upper muffler cover 14 defines an upper muffler chamber 16 therein. The lower muffler cover 15 is provided below the compression section 5 in the internal space 7 and above the oil sump 8. A lower muffler chamber 17 is formed inside the lower muffler cover 15. The lower muffler chamber 17 communicates with the upper muffler chamber 16 via a communication passage (not shown) formed in the compression section 5. A discharge hole 18 for discharging the compressed refrigerant is formed between the upper muffler cover 14 and the shaft 3, and the upper muffler chamber 16 communicates with the internal space 7 via the discharge hole 18.

[0014] The compression section 5 compresses the refrigerant supplied from the suction pipe 11 as the shaft 3 driven by the electric motor 6 rotates, and supplies the compressed refrigerant to the upper muffler chamber 16 and the lower muffler chamber 17. The refrigerant is compatible with the lubricating oil.

[0015] (Electric motor) The electric motor 6 is disposed above the compression section 5 in the internal space 7. The electric motor 6 is a three-phase electric motor and includes a rotor 21 and a stator 22. The rotor 21 is fixed to the shaft 3. The stator 22 is formed in a roughly cylindrical shape and is disposed on the outer periphery of the rotor 21 so as to surround the rotor 21, and is fixed to the container 2. The stator 22 includes a stator core 23, a lower insulator 25B as a first insulator, an upper insulator 25A as a second insulator, and a plurality of windings 46.

[0016] The upper insulator 25A is attached to the upper end of the stator core 23 in the axial direction of the shaft 3. The lower insulator 25B is attached to the lower end of the stator core 23 in the axial direction of the shaft 3. The upper insulator 25A and the lower insulator 25B are an example of an insulating part that insulates the stator core 23 from the windings 46. In this embodiment, the upper insulator 25A and the lower insulator 25B are formed to have the same shape, and are used as the upper insulator 25A when provided at the upper end of the stator core 23, and are used as the lower insulator 25B when provided at the lower end of the stator core 23. Hereinafter, in this embodiment, the upper insulator 25A and the lower insulator 25B will be collectively referred to as the insulator 25. Note that this embodiment illustrates a case where the upper insulator 25A and the lower insulator 25B have the same shape, but the upper insulator 25A and the lower insulator 25B may be formed to have different shapes.

[0017] Fig. 2 is a bottom view showing stator core 23 in the embodiment. As shown in Fig. 2, stator core 23 is formed by stacking a plurality of metal plates made of a soft magnetic material, such as silicon steel plates (electromagnetic steel plates), and includes a yoke portion 31 and a plurality of stator core teeth portions 32 (32-1 to 32-9). Yoke portion 31 is formed in a generally annular (cylindrical) shape. Of the plurality of stator core teeth portions 32-1 to 32-9, first stator core teeth portion 32-1 is formed in a generally columnar shape extending in the radial direction of stator core 23. One end of first stator core teeth portion 32-1 is formed so as to be connected to the inner circumferential surface of yoke portion 31, i.e., it extends from the inner circumferential surface of yoke portion 31 toward the inside in the radial direction of yoke portion 31. Of the multiple stator core teeth portions 32-1 to 32-9, stator core teeth portions 32-2 to 32-9 that are different from first stator core teeth portion 32-1 are also formed in a generally cylindrical shape, similar to first stator core teeth portion 32-1, and extend radially inward from the inner circumferential surface of yoke portion 31. In the case of stator 22 with nine slots, the multiple stator core teeth portions 32-1 to 32-9 are formed on the inner circumferential surface of yoke portion 31 so as to be equally spaced at 40° intervals in the circumferential direction of yoke portion 31.

[0018] FIG. 3 is a perspective view schematically illustrating an insulator 25 according to an embodiment. As shown in FIG. 3, the insulators 25 (upper insulator 25A and lower insulator 25B) are formed into an annular shape and made of an insulating material such as polybutylene terephthalate resin (PBT). As shown in FIG. 3, the insulator 25 has an outer peripheral wall portion 41, a plurality of insulator teeth 42 (42-1 to 42-9) that serve as a winding body around which a conductive wire (winding 46) is wound, and a plurality of flange portions 43 (43-1 to 43-9). The outer peripheral wall portion 41 is formed into a generally cylindrical shape. A plurality of slits 44 are formed in the outer peripheral wall portion 41 at intervals in the circumferential direction of the outer peripheral wall portion 41, the slits 44 extending along the central axis of the outer peripheral wall portion 41 from one end in a direction along the central axis of the outer peripheral wall portion 41 (the axial direction of the shaft 3). Furthermore, the other end of the outer peripheral wall portion 41 in the direction along the central axis of the outer peripheral wall portion 41 contacts the stator core 23. In other words, the multiple slits 44 are formed to extend from one end of the outer peripheral wall portion 41 opposite the stator core 23 toward the stator core 23. When a winding 46 (conductor) drawn from a winding portion 45 (described later) is passed through each slit 44, the winding 46 drawn from the inner peripheral side to the outer peripheral side of the outer peripheral wall portion 41 forms a crossover wire 49 that is laid along the outer peripheral surface of the outer peripheral wall portion 41. Note that the insulator 25 shown in FIG. 3 schematically illustrates the shape and arrangement of each slit 44 in the outer peripheral wall portion 41, and the shape and arrangement of each slit 44 will be described in detail later.

[0019] Of the multiple insulator teeth 42-1 to 42-9, the first insulator tooth 42-1 is formed in the shape of a right column with a roughly semicircular cross section. One end of the first insulator tooth 42-1 is formed to be connected to the inner circumferential surface of the outer peripheral wall 41, that is, it extends from the inner circumferential surface of the outer peripheral wall 41 to the radially inward direction of the outer peripheral wall 41. Of the multiple insulator teeth 42-1 to 42-9, the insulator teeth 42-2 to 42-9 different from the first insulator tooth 42-1 are also formed in the shape of a right column with a roughly semicircular cross section, like the first insulator tooth 42-1, and extend from the inner circumferential surface of the outer peripheral wall 41 to the radially inward direction of the outer peripheral wall 41. The multiple insulator teeth 42-1 to 42-9 are formed on the inner peripheral surface of the outer peripheral wall 41 and are arranged at equal intervals of 40 degrees in the circumferential direction of the outer peripheral wall 41. Note that the insulator teeth 42 in the embodiment are not limited to a shape of a straight column having a substantially semicircular cross section, and may be formed, for example, in a shape of a straight column having a substantially polygonal cross section.

[0020] The plurality of flange portions 43-1 to 43-9 correspond to the plurality of insulator teeth portions 42-1 to 42-9 and are each formed in a generally semicircular plate shape. Of the plurality of flange portions 43-1 to 43-9, the first flange portion 43-1 corresponding to the first insulator tooth portion 42-1 is continuous with the other end of the first insulator tooth portion 42-1 and formed integrally with the first insulator tooth portion 42-1. Similarly to the first flange portion 43-1, the other flange portion 43 of the plurality of flange portions 43-1 to 43-9 that is different from the first flange portion 43-1 is also continuous with the other end of the plurality of insulator teeth portions 42-1 to 42-9 and formed integrally with the respective insulator teeth portions 42-1 to 42-9.

[0021] FIG. 4 is a bottom view of the stator 22 according to the embodiment, as viewed from the lower insulator 25B side. As shown in FIG. 4, a plurality of windings 46 (U-phase windings 46-U1 to 46-U3, V-phase windings 46-V1 to 46-V3, and W-phase windings 46-W1 to 46-W3, which will be described later) are wound around each of the stator core teeth 32-1 to 32-9 of the stator core 23. As shown in FIG. 4, a winding portion 45 is formed around each of the stator core teeth 32-1 to 32-9 by the windings 46 of each phase. Each winding portion 45 has multiple layers (e.g., six to eight layers) of windings 46, each of which is formed by winding a conductor around the stator core teeth 32 via the insulator teeth 42. The nine slots of the winding portions 45 are indicated by the reference numerals 1 to 9 in clockwise order in FIG. 4. The nine winding portions 45 are arranged so that the three phases repeat in the same order along the circumferential direction of the stator core 23. That is, the nine winding portions 45 are arranged so that the U phase, V phase, and W phase repeat in clockwise order in FIG.

[0022] The electric motor 6 in this embodiment is a 6-pole, 9-slot concentrated winding type electric motor. The plurality of windings (conductors) 46 includes a plurality of U-phase windings 46-U1 to 46-U3 that form the U-phase winding portion 45, a plurality of V-phase windings 46-V1 to 46-V3 that form the V-phase winding portion 45, and a plurality of W-phase windings 46-W1 to 46-W3 that form the W-phase winding portion 45.

[0023] Although the electric motor 6 of the embodiment is configured with nine slots, the number of slots, that is, the number of winding portions 45 (or the number of stator core teeth portions 32) is not limited thereto.

[0024] Furthermore, although the stator core 23 in the embodiment has an annular yoke portion 31 formed integrally therewith, the yoke portion may be formed by connecting and assembling a plurality of arc-shaped yoke components (not shown) into an annular shape. Furthermore, although the stator core teeth 32 of the stator core 23 in the embodiment extend from the inner peripheral surface of the yoke portion 31 radially inward of the yoke portion 31, they may extend from the outer peripheral surface of the yoke portion 31 radially outward of the yoke portion 31. Similarly, the insulator teeth 42 of the insulator 25 are not limited to a shape extending from the inner peripheral surface of the outer peripheral wall portion 41 radially inward of the outer peripheral wall portion 41, but may extend from the outer peripheral surface of the outer peripheral wall portion 41 radially outward of the outer peripheral wall portion 41. Furthermore, the insulator teeth 42 in the embodiment are not limited to a shape of a right column having a substantially semicircular cross section, and may be formed, for example, in a shape of a right column having a substantially polygonal cross section.

[0025] (Characteristic structure of electric motor) Next, a description will be given of the characteristic structure of the electric motor 6 of this embodiment. The characteristic of this embodiment includes the winding state of the winding 46 of the first layer 1L of the winding portion 45.

[0026] 5 is a cross-sectional view schematically showing a winding portion (coil) 45 in an electric motor 6 according to the embodiment. In FIG. 5, the numbers "1 to 8" attached to the windings 46 (conductors) of each layer of the winding portion 45 indicate the first layer 1L to the eighth layer 8L.

[0027] As shown in FIG. 5 , the winding portion 45 in this embodiment is wound at a predetermined winding pitch P (the amount of movement of the nozzle N in the radial direction Y per turn) for each layer of the winding portion 45 so as to be aligned in the radial direction Y of the yoke portion 31 (which also corresponds to the radial direction Y of the outer peripheral wall portion 41; hereinafter, simply referred to as the radial direction Y). The winding 46 wound as the first layer 1L of the winding portion 45 is wound so as to be in contact with the surface of the insulator teeth 42 on which the conductor wire is wound (hereinafter, referred to as the surface of the insulator teeth 42). When the winding pitch of the conductor wire (winding 46) in one layer of the winding portion 45 is P and the outer diameter of the conductor wire is B, the winding pitch P of the winding wire 46 (conductor wire) wound as the first layer 1L in the radial direction Y satisfies P>B. In addition, in the winding portion 45, the winding pitch P of the wire 46 (conductor) wound as at least one layer from the second layer 2L onwards satisfies P≦B. By winding the wire 46 at such a winding pitch P, no irregular winding occurs in the wire 46 of the first layer 1L, and the space factor of the winding portion 45 is increased. This will be described in more detail later (see the explanation of the manufacturing method of the electric motor).

[0028] The winding pitch P here refers to the amount of movement of the nozzle N in the radial direction Y per turn of the conductor (winding 46) wound in the radial direction Y around the insulator teeth 42 and the stator core teeth 32, and is different from the pitch dimension between adjacent windings 46 in the radial direction Y. For convenience, the winding pitch P is also shown as the pitch dimension in the drawings, but in the following description, the winding pitch P refers to the amount of movement of the nozzle N. Note that the amount of movement of the nozzle N refers to the amount of change in the relative position between the nozzle N and the insulator teeth 42. In other words, when changing the relative position of the nozzle N with respect to the insulator teeth 42, the insulator teeth 42 side may be fixed and the nozzle N side may move, the nozzle N side may be fixed and the insulator teeth 42 side may move, or both the insulator teeth 42 side and the nozzle N side may move.

[0029] In the embodiment, for example, the outer diameter B of the conductor and the winding pitch P of the first layer 1L and the second layer 2L satisfy P>B, and the winding pitch P of the third layer 3L to the eighth layer 8L satisfies P≦B. In other words, in the first layer 1L and the second layer 2L of the winding portion 45, the windings 46 are wound so that a gap G is generated between adjacent windings 46 in the radial direction Y, and in the third layer 3L and onwards, the windings 46 are wound so that adjacent windings 46 in the radial direction Y are in close contact with each other.

[0030] (Electric motor manufacturing method) The manufacturing method for the electric motor of this embodiment includes a winding step in which a conductor wire is wound around the stator core teeth 32 via the insulator teeth 42 to form a winding portion (coil) 45. As shown in Fig. 5, in the winding step of this embodiment, the conductor wire is wound using a winding machine (not shown) having a nozzle N that supplies the conductor wire. A feature of the manufacturing method for the electric motor of this embodiment includes controlling, in the winding step, the movement amount (winding pitch P) of the nozzle N that supplies the conductor wire to be wound in the first layer 1L of the winding portion 45 by a control unit C of the winding machine.

[0031] In the winding process, a conductor wire is supplied from a nozzle N that moves in the radial direction Y of the stator core 23, and a winding 46 is wound around the stator core teeth 32 of the stator core 23 and the insulator teeth 42 of the insulator 25 that is attached to and overlaps the stator core teeth 32, and a crossover wire 49 drawn out from the winding portion 45 is wound around the outer peripheral wall 41 of the insulator 25. In the embodiment, when forming each of the three-phase winding portions 45 using a winding machine, for example, a so-called three-nozzle winding method is applied, in which a winding portion 45 is formed for each phase using three nozzles N, and the winding portions 45 for each phase are formed in order to form the three-phase winding portions 45.

[0032] (Comparative Example) First, for comparison with the winding process in the manufacturing method of the motor of the embodiment, the winding process in the manufacturing method of the motor of the comparative example will be described. In the winding process in the comparison, in order to increase the occupation ratio of the winding portion, when the outer diameter of the conductor wire in the state before being wound is B and the winding pitch (the amount of movement of the nozzle N in the radial direction Y per turn) of the winding wire of the first layer 1L of the winding portion is P, the conductor wire is wound so as to satisfy P < B (for example, P = 0.8B). Note that the outer diameter B of the conductor wire tends to be slightly reduced in the outer diameter of the winding wire wound around the winding portion due to the conductor wire stretching in the longitudinal direction by the tension applied when the conductor wire is wound around the stator core tooth portion 32 through the insulator tooth portion 42.

[0033] FIG. 6 is a cross-sectional view schematically showing the winding portion 145 in the motor of the comparative example. In FIG. 6, the numbers "1 to 8" attached to the winding wires 46 of each layer of the winding portion 145 indicate the first layer 1L to the eighth layer 8L. As shown in FIG. 6, in the winding portion 145 of the comparative example, for example, the winding wire 46 forms 8 layers, and the conductor wire is wound so that the winding pitch P of all layers from the first layer 1L to the eighth layer 8L satisfies P < B. For this reason, the first layer 1L to the eighth layer 8L of the winding portion 145 are wound so that the adjacent winding wires 46 are in close contact with each other in the radial direction Y.

[0034] (Winding process of the comparative example) FIG. 7 is a cross-sectional view for explaining the winding portion when the winding wire of the first layer 1L is normally wound in the winding process of the comparative example. As shown in FIG. 7, in the comparative example, in the first layer 1L, the winding wire 46 of the second turn (second turn 2T) slides down the outer peripheral surface of the winding wire 46 of the first turn (first turn 1T) to the other end side in the radial direction Y (the inner diameter side which is the inner side in the radial direction Y), and then, following the winding wire 46 of the first turn 1T, the winding wire 46 of the second turn 2T and the winding wire 46 of the third turn 3T are wound in sequence so as to be adjacent and in contact with each other. After the fourth turn 4T and later, since the winding pitch P satisfies P < B, the conductor wire is wound so that the adjacent winding wires 46 are aligned in contact with each other with respect to the radial direction Y. That is, when each winding wire 46 (conductor wire) forming the first layer 1L is normally wound, each winding wire 46 of the first layer 1L is wound tightly without a gap.

[0035] FIG. 8 is a cross-sectional view for explaining the case where the winding position of the winding 46 of the first layer 1L is displaced in the winding process of the comparative example. FIG. 9 is a side view for explaining the case where the winding position of the winding 46 is displaced in the winding process of the comparative example.

[0036] As shown in FIG. 8, in the winding process of the comparative example, in the first layer 1L wound on the insulator teeth portion 42, for example, the winding 46 of the second turn 2T wound following the winding 46 of the first turn 1T slides from the position adjacent to and contacting the winding 46 of the first turn 1T to the other end side in the radial direction Y (the inner diameter side which is the inner side in the radial direction Y), and the winding position of the winding 46 of the second turn 2T may be greatly separated from the winding 46 of the first turn 1T.

[0037] At this time, in the comparative example, since the winding pitch (the amount of movement of the nozzle N in the radial direction Y per turn) P is P < B (P = 0.8B), the winding 46 of the third turn 3T is sent by 0.8B from the winding position where the winding 46 of the second turn 2T would normally be wound. For this reason, the winding 46 of the third turn 3T cannot cross over the winding 46 of the second turn 2T toward the other end side in the radial direction Y (the inner diameter side which is the inner side in the radial direction Y), and is wound on the side of the winding 46 of the first turn 1T (the outer diameter side which is one end side in the radial direction Y) rather than the position of the winding 46 of the second turn 2T. As a result, the winding 46 of the third turn 3T enters between the winding 46 of the first turn 1T and the winding 46 of the second turn 2T, and a part of the winding 46 of the third turn 3T rides on and is wound on the winding 46 of the second turn 2T, resulting in winding disorder.

[0038] Subsequently, from the winding position of the winding 46 of the second turn 2T which is originally located at the winding position where the winding 46 of the third turn 3T would be normally wound, the winding 46 of the fourth turn 4T is sent by 0.8B which is smaller than the outer diameter B of the conductor in the state before being wound. As a result, the winding 46 of the fourth turn 4T is wound adjacent to the winding 46 of the second turn 2T on the side opposite to the side of the winding 46 of the third turn 3T in the radial direction Y.

[0039] Also, as shown in FIG. 9, for example, when the windings 46 of the third turn 3T and the fourth turn 4T are inserted between the winding 46 of the first turn 1T and the winding 46 of the second turn 2T, the winding 46 of the second turn 2T continues to be displaced in the direction away from the winding 46 of the first turn 1T in the radial direction Y (the direction approaching the flange portion 43), along with winding disorder. In particular, the winding 46 of the second turn 2T is pulled to the other end side of the radial direction Y (the inner diameter side which is the inner side of the radial direction Y), resulting in a decrease in cross-sectional area, an increase in electrical resistance, and an increase in the heat generation amount of the winding 46. Further, when winding disorder occurs in the first layer 1L, the conductor wound around the second layer 2L rides on the winding 46 that has caused the winding disorder, leading to a problem that the winding portion 45 bulges significantly in the stacking direction (the winding diameter direction, for example, the axial direction of the shaft 3), and the winding portion 45 is distorted and enlarged.

[0040] As described above, in order to increase the occupation ratio of the winding portion 145, when the winding pitch P of the winding 46 (conductor) wound around the first layer 1L satisfies P < B and the conductor is wound, there is a problem that winding disorder is likely to occur in the winding 46 wound around the first layer 1L. Here, as an example, the case where the winding disorder starts when the winding 46 of the second turn 2T in the first layer 1L slides on the insulator teeth portion 42 is shown. However, in the first layer 1L where the winding 46 is wound in contact with the surface of the insulator teeth portion 42, similar winding disorder may occur at any position in the radial direction Y.

[0041] (Winding Process of the Embodiment) FIG. 10 is a flowchart for explaining the winding process in the method for manufacturing an electric motor according to an embodiment. In the winding process of the comparative example described above, the winding pitch P in the first layer 1L of the winding portion 45 is P < B (P = 0.8B), whereas in the winding process of the embodiment, as shown in FIG. 10, the conductor is wound so that the winding pitch P in the first layer 1L of the winding portion 45 satisfies P > B (step S1). When winding the conductor around the first layer 1L, the nozzle N moves along the radial direction Y from the outer peripheral wall portion 41 side, which is one end side in the radial direction Y of the insulator tooth portion 42, toward the flange portion 43 side, which is the other end side in the radial direction Y. The winding pitch P, which is the amount of movement of the nozzle N, is controlled by the control unit C of the winding machine.

[0042] Subsequently, in the winding process of the embodiment, the conductor is wound around the second layer L2 of the winding portion 45 so that the winding pitch P satisfies P > B (step S2). When winding the conductor around the second layer 2L, the nozzle N moves along the radial direction Y from the flange portion 43 side, which is the other end side in the radial direction Y of the insulator tooth portion 42, toward the outer peripheral wall portion 41 side, which is one end side in the radial direction Y.

[0043] Next, in the winding process of the embodiment, the conductor is wound around the third layer L3 of the winding portion 45 so that the winding pitch P satisfies P ≤ B (step S3). When winding the conductor around the third layer 3L, the nozzle N moves along the radial direction Y from the outer peripheral wall portion 41 side (one end side in the radial direction Y) of the insulator tooth portion 42 toward the flange portion 43 side (the other end side in the radial direction Y). In the winding process of the embodiment, the conductor is also wound around the fourth layer 4L and subsequent layers of the winding portion 45 so that the winding pitch P satisfies P ≤ B (step S4).

[0044] As described above, the nozzle N winds the conductor wire while moving back and forth in the radial direction Y. That is, the nozzle N winds the conductor wire in the first layer 1L on the outgoing path of the reciprocating movement, winds the conductor wire in the second layer 2L on the return path of the reciprocating movement, and repeats the reciprocating movement a predetermined number of times to wind the conductor wire in the third layer 3L and beyond. In the winding process of the embodiment, the stator core 23 and the insulator 25 are rotated around the radial direction Y in accordance with the movement of the nozzle N, so that the conductor wire is wound around the stator core teeth 32 via the insulator teeth 42. Note that the direction in which the winding 46 is wound with respect to the radial direction Y in the first layer 1L, i.e., the movement direction of the nozzle N in the first layer 1L, is not limited to the direction from the outer circumferential wall 41 side toward the flange 43 side, and may be the direction from the flange 43 side toward the outer circumferential wall 41 side.

[0045] 11 is a cross-sectional view illustrating a case where the winding 46 of the first layer 1L is wound normally in the winding process of the embodiment. As shown in FIG. 11, in the winding process of the embodiment, in the first layer 1L, the conductor is wound in order from the first turn 1T of the winding 46 to the second turn 2T of the winding 46 and the third turn 3T of the winding 46 so that a gap G is left between them. From the fourth turn 4T onwards, the conductor is wound so that the winding pitch P satisfies P>B, and thus the windings 46 are aligned in the radial direction Y with a gap G between them.

[0046] 12 is a cross-sectional view illustrating a case where the winding position of the first layer 1L winding 46 is shifted during the winding process of the embodiment. As shown in Fig. 12, in the winding process of the embodiment as well, similar to the winding process of the comparative example described above (see Fig. 8), in the first layer 1L, for example, the second turn 2T winding 46 wound following the first turn 1T winding 46 may slip in the radial direction Y on the insulator teeth 42 from the winding position where the second turn 2T winding 46 would normally be wound, and the winding position of the second turn 2T winding 46 may become separated from the first turn 1T winding 46.

[0047] Even in such a case, in the winding process of the embodiment, the conductor wire is wound so that the winding pitch P of the first layer 1L satisfies P>B, thereby ensuring an appropriate amount of movement of the nozzle N. This allows the next third-turn 3T winding 46 to smoothly pass over the misaligned second-turn 2T winding 46. The third-turn 3T winding 46 is wound around the surface of the insulator teeth 42 while contacting the flange 43 side of the outer circumferential surface of the second-turn 2T winding 46, for example. Therefore, the third-turn 3T winding 46 does not get caught between the first-turn 1T winding 46 and the second-turn 2T winding 46 as in the comparative example, but is appropriately wound on the opposite side of the second-turn 2T winding 46 from the first-turn 1T winding 46.

[0048] In other words, the winding pitch P of the first layer 1L (the movement amount of the nozzle N) is preferably set to a value obtained by adding a predetermined value corresponding to the maximum amount of misalignment of the winding position of the winding 46 expected in the first layer 1L, i.e., the maximum amount of slippage of the winding 46, to the outer diameter B of the conductor (the upper limit of the dimensional tolerance). The winding pitch P of the first layer 1L may be set to a value equal to or larger than the value at which the next winding 46 is wound so as to contact the outer peripheral surface (the flange 43 side of the outer peripheral surface) of the misaligned winding 46. This allows the next winding 46 to pass over the misaligned winding 46 in the winding process of the embodiment. Therefore, in the winding process of the embodiment, the order of each turn of the winding 46 wound on the first layer 1L is not disturbed, and each turn of the winding 46 is wound in the correct order, preventing winding irregularities in the first layer 1L.

[0049] As described above, even if the winding position of the previously wound winding 46 is shifted for the windings 46 after the fourth turn 4T, the next winding 46 is wound while smoothly passing over the previously wound winding 46, thereby preventing winding irregularities from occurring in the first layer 1L.

[0050] As described above, in the winding process of the embodiment, the conductor is wound so that the winding pitch P of the first layer 1L satisfies P > B, thereby preventing winding irregularities in the winding 46 of the first layer 1L. Furthermore, the winding pitch P of at least one layer from the second layer 2L onward satisfies P ≦ B, thereby increasing the space factor of the winding portion 45. In the embodiment, the outer diameter B of the conductor before winding and the winding pitch P of the third layer 3L and subsequent layers of the winding portion 45 satisfy P ≦ B. It is preferable that the winding pitch P of all layers from the second layer 2L onward satisfy P ≦ B, which can both prevent winding irregularities in the first layer L1 and maximize the space factor of the winding portion 45. The outer diameter B of the conductor before winding can be approximated to the outer diameter of the conductor in the crossover wire 49 extending from the winding portion 45 to the outer peripheral wall portion 41, as described below. Therefore, in this embodiment, the outer diameter of the conductor in the crossover wire 49 extending from the winding portion 45 to the outer peripheral wall portion 41 is treated as the outer diameter B of the conductor in the state before being wound.

[0051] In this embodiment, the winding pitch P of all layers from the second layer 2L onward is not limited to satisfying P≦B, and the second layer 2L onward may include layers whose winding pitch P satisfies P>B. Furthermore, when the winding pitch P of all layers from the second layer 2L onward satisfies P≦B, the winding pitch P of each layer from the second layer 2L onward may be made different. For example, the winding pitch P of each layer from the second layer 2L onward may be increased or decreased, or the winding pitch P of only any layer may be made different.

[0052] Furthermore, in the winding process of the embodiment, it is preferable that the conductor is wound in the first layer 1L of the winding section 45 so that the outer diameter B of the conductor and the winding pitch P satisfy P>1.02B. In other words, it is preferable that the outer diameter B and the winding pitch P of the conductor before being wound in the first layer 1L of the winding section 45 satisfy P>1.02B. This allows the winding process of the embodiment to appropriately feed the conductor in the radial direction Y when winding the conductor in the first layer 1L so that the next wound conductor reliably passes over the previously wound winding 46. As a result, it is possible to further prevent winding irregularities in the first layer 1L during the winding process.

[0053] In the winding process of the embodiment, it is preferable to wind the conductor in the first layer 1L of the winding section 45 so that the outer diameter B of the conductor and the winding pitch P satisfy the relationship 2B>P. In other words, it is preferable that the outer diameter B of the conductor and the winding pitch P of the winding 46 wound in the first layer 1L of the winding section 45 before winding satisfy the relationship 2B>P. This prevents winding irregularities in the first layer 1L and avoids a decrease in the number of turns (number of windings) of the winding 46 that would otherwise occur with an increase in the winding pitch P. If the winding pitch P of the winding 46 in the first layer 1L is set to 2B or more, the number of turns of the winding 46 in the second layer 2L and subsequent layers (in the embodiment, the third layer 3L and subsequent layers) must be significantly increased to compensate for the decrease in the number of turns in the first layer 1L and ensure an appropriate space factor. In this case, the winding 46 may easily bulge in the lamination direction (winding diameter direction) from the second layer 2L onward, or the number of layers forming the winding section 45 may increase, which may result in a decrease in the alignment of the winding 46. Furthermore, even if the winding position of the previously wound winding 46 in the first layer 1L of the winding section 45 shifts, the amount of shift rarely exceeds the outer diameter B of the conductor. Therefore, in the winding process of the embodiment, by winding the conductor so that 2B>P is satisfied as described above, the reliability of the wound state of the winding 46 is ensured and a decrease in the alignment of the winding 46 in the winding section 45 can be suppressed.

[0054] In the winding process of the embodiment, it is preferable that the conductor is wound such that the outer diameter B of the conductor before winding and the winding pitch P of at least one layer after the second layer 2L (in the embodiment, the third layer 3L or later) satisfy 0.82B≦P≦B. In other words, it is preferable that the outer diameter B of the conductor before winding and the winding pitch P of the winding 46 wound on at least one layer after the second layer 2L (in the embodiment, the third layer 3L or later) in the winding section 45 satisfy 0.82B≦P≦B. Unlike the winding 46 of the first layer 1L that contacts the surface of the insulator teeth portion 42, the winding 46 wound on the second layer 2L or later is wound on top of the winding 46 wound on the layer immediately below it, which restricts movement and makes it less likely to slip, thereby reducing winding irregularities. For this reason, in the second layer 2L and thereafter, the winding pitch P must satisfy 0.82B≦P≦B, for example, by making it small enough to be approximately the same as the outer diameter of the conductor 46a (see FIG. 5) in the conducting wire, thereby increasing the space factor of the winding portion 45. On the other hand, if the winding pitch P is smaller than 0.82B, the next winding 46 may not be able to get over the previously wound winding 46, which may result in the second layer 2L and thereafter not being able to be properly formed, which is not preferable.

[0055] It is preferable that the relational expression relating to the outer diameter B of the conductor (for example, "the winding pitch P of the first layer 1L satisfies P>B") holds even when this outer diameter B is set to the upper limit of the dimensional tolerance of the outer diameter of the conductor (maximum finished outer diameter), and since the winding pitch P can be set optimally, the effect of preventing irregular winding of the winding 46 wound in the first layer 1L can be most appropriately obtained.

[0056] 5, the conductor (winding 46) has a conductor 46a and an insulating film 46b covering the conductor 46a, and the outer diameter B of the conductor is a dimension that includes the thickness of the insulating film 46b. In the conductor in this example, for example, the outer diameter of the conductor 46a is 0.8 mm, and the upper limit of the dimensional tolerance of the outer diameter B of the conductor covered with the insulating film 46b is set to 0.88 mm.

[0057] The insulating film 46b contains, for example, polyamideimide, and has a static friction coefficient of 0.12 or less. In the embodiment, the insulating film 46b has high lubricity, with a static friction coefficient of approximately 0.05. A conductor (winding 46) with a small static friction coefficient on the surface of the insulating film 46b can prevent the conductor from getting caught during the winding process, but the first layer 1L that contacts the surface of the insulator teeth 42 is prone to slippage, making the winding position of the winding 46 prone to shifting. Therefore, when using a conductor with a small static friction coefficient on the insulating film 46b as described above, ensuring that the winding pitch P of the first layer 1L satisfies P>B, as in the embodiment, is highly effective in preventing irregular winding of the first layer 1L.

[0058] Furthermore, the insulator 25 contains glass fiber in an amount of 15% by weight or more and 45% by weight or less, which increases the dynamic friction coefficient on the surface of the insulator teeth 42. Adding less than 15% by weight increases the molding shrinkage of the resin material containing the glass fiber, reducing the moldability of the insulator 25, which is undesirable. Adding more than 45% by weight is undesirable because it does little to increase the dynamic friction coefficient and simply increases manufacturing costs. The addition of glass fiber in the insulator 25 prevents the winding 46 wound on the surface of the insulator teeth 42 from slipping, which prevents irregular winding of the first layer 1LL and improves the reliability of the conductor wound in the first layer 1L.

[0059] The conductor (winding 46) has a tensile strength of 460 [N / mm 2 ], and for example, annealed copper wire is used. A conductor with such low tensile strength is prone to stretching due to the tension applied when winding, which may reduce the reliability of the conductor (for example, if the conductor stretches and its cross-sectional area decreases, the amount of heat generated increases. Also, if the conductor stretches and eventually breaks, no current will flow through the winding and the motor will no longer operate). Therefore, when a conductor with low tensile strength is used as in the example, ensuring that the winding pitch P of the first layer 1L satisfies P>B is particularly effective in preventing irregular winding of the first layer 1L and reducing the reliability of the conductor.

[0060] In the electric motor 6 of the embodiment, when A1 is a first cross-sectional area perpendicular to the longitudinal direction of the winding 46 wound in the first layer 1L and A2 is a second cross-sectional area perpendicular to the longitudinal direction of the jumper wire 49 extending from the winding portion 45 to the outer peripheral wall portion 41 (see FIG. 5 ), (A1 / A2) > 0.85 is satisfied. By satisfying (A1 / A2) > 0.85, the elongation rate (the rate at which the conductor wire elongates from its original length) of the winding 46 wound in the first layer 1L is kept to 15% or less. The first cross-sectional area A1 and the second cross-sectional area A2 include the cross-sectional area of ​​the insulating film 46b. The outer diameter of the jumper wire 49 drawn out from the winding portion 45 is less susceptible to elongation due to tension, unlike the winding 46. Therefore, the outer diameter of the jumper wire 49 is larger than the outer diameter of the conductor wire forming the winding 46 and is closer to the outer diameter B of the conductor wire before winding. By satisfying (A1 / A2)>0.85 in this way, the winding 46 of the first layer 1L of the winding portion 45 is wound in a manner that prevents it from stretching to the extent that would cause a significant increase in the amount of heat generated or that would pose a risk of breakage.

[0061] As described above, the crossover wire 49 drawn out from the winding portion 45 is less likely to stretch due to tension than the winding 46, and therefore has a larger outer diameter than the portion of the conductor forming the winding 46 and is closer to the outer diameter B of the conductor before being wound. Therefore, the outer diameter B of the conductor before being wound can be approximated to the outer diameter of the conductor as the crossover wire 49 extending from the winding portion 45 to the outer peripheral wall 41. Therefore, in this embodiment, the outer diameter of the conductor of the crossover wire 49 extending from the winding portion 45 to the outer peripheral wall 41 is treated as the outer diameter B of the conductor before being wound.

[0062] In the insulator teeth 42 of the embodiment, when viewed in cross section along the radial direction Y, the surface of the insulator teeth 42 around which the conductor wire is wound has a flat surface 42a extending along the radial direction Y and an arc-shaped curved surface 42b that is inclined relative to the flat surface 42a. The flat surface 42a extends from the inner circumferential surface of the outer peripheral wall 41. The curved surface 42b is formed continuously from the side surface of the flange 43 facing the outer peripheral wall 41 to the flat surface 42a.

[0063] When the length of the winding portion 45 in the radial direction Y of the flat surface 42a is M and the number of turns (winding number) of the winding 46 wound around the flat surface 42a in the first layer 1L is T, (B × T) < M is satisfied. That is, it is wound so that a gap G is generated between the windings 46 wound around the flat surface 42a.

[0064] Also, in the winding process of the embodiment, by winding the conducting wire using a winding machine having a nozzle N, the control unit C of the winding machine controls the movement amount (winding pitch P) of the nozzle N, so that a winding portion 45 without winding disorder can be easily formed with a desired winding pitch P.

[0065] (Modifications 1 and 2) In the winding process of the above-described embodiment, the conducting wire was wound so that the winding pitch P of the first layer 1L and the second layer 2L satisfies P > B, but the conducting wire may be wound so that the winding pitch P after the second layer 2L satisfies P ≤ B.

[0066] FIG. 13 is a cross-sectional view showing the winding state of the winding 46 in the winding process of Modification 1. FIG. 14 is a cross-sectional view showing the winding state of the winding 46 in the winding process of Modification 2. In FIGS. 13 and 14, the numbers "1 to 8" attached to the windings 46 of each layer of the winding portions 55 and 56 indicate the first layer 1L to the eighth layer 8L. In FIG. 14, only the first layer 1L and the second layer 2L are shown.

[0067] In the winding processes of Modifications 1 and 2, due to the elongation of the conducting wire caused by the tension applied during winding, the outer diameter of the winding 46, which is the conducting wire in the wound state, is about 0.95 times the outer diameter of the conducting wire in the state before winding. Therefore, the cross-sectional area of the winding 46, which is the conducting wire in the wound state, is about 0.9 times the cross-sectional area of the conducting wire in the state before winding. In the present embodiment and the modifications, the outer diameter of the conducting wire in the state before winding is B. In the winding process of Modification 1, the winding pitch P of the first layer 1L and the second layer 2L of the winding portion 55 is set to 1.1B, and the winding pitch P after the second layer 2L is set to 0.95B. In the winding process of Modification 2, the winding pitch P of the first layer 1L of the winding portion 56 is set to 1.4B, and the winding pitch P after the third layer 3L is set to 0.95B.

[0068] 13 , in the winding process of Modification 1, the windings 46 are aligned and wound to the extent that a small gap G is created between adjacent windings 46 in the first layer 1L of the winding section 55, and the conductor wire is wound without any irregularities in the windings 46 when wound into the first layer 1L. On the other hand, when the winding 46 is wound into the second layer 2L so as to overlap the first layer 1L, part of the winding 46 formed into the first layer 1L is pushed aside by the conductor wire wound into the second layer 2L, causing part of the winding 46 formed into the first layer 1L to shift to one side in the radial direction Y, resulting in locations where relatively large gaps are created between the windings 46 forming the first layer 1L. As a result, when the winding 46 wound in the second layer 2L is placed on top of the first layer 1L, a portion of the winding 46 enters the relatively large gaps between the windings 46 in the first layer 1L, and the windings 46 of the second layer 2L and the windings 46 of the second layer 2L are arranged side by side at the end of the first layer 1L. As a result of the winding 46 of the second layer 2L entering into the first layer 1L at the end of the first layer 1L on the flange 43 side in this way, a portion of the winding 46 wound in the third layer 3L enters into the second layer 2L and the first layer 1L at the end on the flange 43 side. Similarly, on the flange 43 side of the winding section 55, portions of the winding 46 of the fourth layer 4L to the eighth layer 8L are wound in turn so as to enter into the layer below. Even in such a case, if the winding pitch P of the first layer 1L satisfies P>B, the next winding 46 can smoothly overcome the winding 46 whose winding position is shifted in the first layer 1L and be wound appropriately, thereby preventing winding irregularities from occurring when winding the winding 46 of the first layer 1L. Also, since the winding pitch P of at least one layer from the second layer 2L onwards is smaller than the winding pitch P of the first layer 1L, a decrease in the space factor of the winding portion 45 is prevented.

[0069] In this disclosure, the winding 46 in the first layer 1L refers only to the winding 46 wound as the first layer 1L, and the winding 46 that is not overlapped with the second layer 2L but enters the first layer 1L is included in the winding 46 of the second layer 2L. The same applies to the winding 46 in the third layer 3L and beyond.

[0070] 14 , in the winding process of Modification 2, the windings 46 are aligned so that gaps G are created between the windings 46 wound in the first layer 1L of the winding section 56, and the windings 46 are wound without any irregularities in the first layer 1L. As a result, some of the windings 46 wound in the second layer 2L enter the gaps G between the windings 46 wound in the first layer 1L, and the windings 46 of the second layer 2L and the windings 46 of the first layer 1L are arranged side by side in the first layer 1L. As a result of the windings 46 of the second layer 2L entering the first layer 1L in this way, gaps G are created between the windings 46 wound in the second layer 2L, and the windings 46 wound in the third layer 3L and onwards are wound entering the second layer 2L.

[0071] (Effects of the Example) As described above, in the manufacturing method of the electric motor of the embodiment, when the winding pitch of the conductor wound in the radial direction Y of the yoke portion 31 of the stator core 23 is P and the outer diameter of the conductor is B, the conductor is wound in the first layer 1L of the winding portion 45 so that P > B is satisfied in the radial direction Y, and the conductor is wound in at least one layer from the second layer 2L onward so that P ≦ B is satisfied. As a result, even if the winding 46 wound in the first layer 1L slips on the surface of the insulator teeth 42, the winding pitch P of the first layer 1L satisfies P > B, so that the next winding 46 smoothly passes over the misaligned winding 46 and is properly wound, preventing winding irregularities in the first layer 1L. Furthermore, in the embodiment, the winding pitch P of at least one layer from the second layer 2L onward is made smaller than the winding pitch P of the first layer 1L, thereby suppressing a decrease in the space factor of the winding portion 45. Therefore, according to the embodiment, for example, there is no need to change the insulator having grooves to prevent the winding from slipping depending on the outer diameter of the conductor, which avoids an increase in the manufacturing cost of the motor 6. Furthermore, according to the embodiment, the winding 46 of the first layer 1L of the winding portion 45 is prevented from stretching due to winding irregularities, which suppresses an increase in the resistance value and heat generation of the winding 46 and improves the reliability of the conductor wound in the first layer 1L.

[0072] Also, in the manufacturing method of the motor of the embodiment, the conducting wire is wound around the first layer 1L so as to satisfy P > 1.02B. As a result, when the conducting wire is wound around the first layer 1L, the previously wound winding 46 can be appropriately sent in the radial direction Y so that the next winding conducting wire can cross over it, further preventing winding disorder from occurring in the first layer 1L.

[0073] Also, in the manufacturing method of the motor of the embodiment, the conducting wire is wound around the first layer 1L so as to satisfy 2B > P. Thereby, in the first layer 1L, winding disorder can be prevented, and a decrease in the number of turns (winding times) of the winding 46 accompanying an increase in the winding pitch P can be avoided. In addition, according to the embodiment, while ensuring the reliability of the winding state of the winding 46, the number of turns after the second layer 2L and later is increased to compensate for the decrease in the number of turns of the first layer 1L, suppressing a decrease in the alignment of the winding 46 in the winding part 45.

[0074] Also, in the manufacturing method of the motor of the embodiment, the conducting wire is wound around at least one layer after the second layer 2L so as to satisfy 0.82B ≤ P ≤ B. The winding 46 wound after the second layer 2L is wound on top of the winding 46 wound on the layer directly below it, so its movement is restricted and it is difficult to slip, thus suppressing winding disorder. Therefore, for example, by making it approximately the same size as the outer diameter of the conductor 46a in the conducting wire, the occupation ratio of the winding part 45 can be increased.

[0075] Also, in the manufacturing method of the motor of the embodiment, the conducting wire is wound around all layers after the second layer 2L so as to satisfy P < B. Thereby, it is possible to achieve both preventing winding disorder in the first layer L1 and maximizing the occupation ratio of the winding part 45.

[0076] Also, the outer diameter B of the conducting wire wound in the manufacturing method of the motor of the embodiment is the upper limit value of the dimensional tolerance of this outer diameter. Thereby, the effect of preventing winding disorder of the winding 46 in the first layer 1L can be most appropriately obtained.

[0077] In addition, in the method for manufacturing the electric motor of the embodiment, the conductor wire is wound using a winding machine having a nozzle N that supplies the conductor wire. As a result, a control unit C of the winding machine controls the movement amount of the nozzle N (winding pitch P), and thus a wound portion 45 can be easily formed at the desired winding pitch P without any irregular winding. [Explanation of symbols]

[0078] 6 Electric motor 23 stator core 25(25A, 25B) insulator 31 York 32 (32-1 to 32-9) Stator core teeth (teeth) 41 Outer wall 42 (42-1 to 42-9) Insulator teeth (winding drum) 42a flat surface 45, 55, 56 Winding section 46 windings 46a Conductor 46b insulating film 49 Crossover A1 1st cross-sectional area A2 2nd cross-sectional area B Conductor outer diameter P Winding pitch 1L 1st layer 2L~8L 2nd to 8th layers (at least one layer after the 2nd layer) M length N nozzle 1T~4T 1st turn to 4th turn Y radial direction

Claims

1. a stator core having an annular yoke portion and teeth portions extending radially from the yoke portion; an insulator having a winding drum attached to the tooth portion; a winding portion in which a plurality of layers are formed by windings in which a conductor is wound around the teeth portion via the winding drum portion, When the winding pitch of the conductor wire wound side by side in the radial direction is P and the outer diameter of the conductor wire is B, a first layer of the winding portion in the radial direction, the conductor wire is wound so that P>B is satisfied, and a second or subsequent layer of the winding portion in at least one layer is wound so that P≦B is satisfied.

2. The conductor is wound in the first layer so that P>1.02B is satisfied. A method for manufacturing the electric motor according to claim 1.

3. The conductor is wound in the first layer so that 2B>P is satisfied. The method for manufacturing the electric motor according to claim 1 or 2.

4. The conductive wire is wound in the at least one layer so that 0.82B≦P≦B is satisfied. A method for manufacturing the electric motor according to claim 1.

5. The conductor is wound so that P≦B is satisfied in the second and subsequent layers of the winding portion. A method for manufacturing the electric motor according to claim 1.

6. The outer diameter B of the conductor is the upper limit of the dimensional tolerance of the outer diameter. A method for manufacturing the electric motor according to claim 1.

7. winding the conductor wire using a winding machine having a nozzle for supplying the conductor wire; A method for manufacturing the electric motor according to claim 1.

8. a stator core having an annular yoke portion and teeth portions extending radially from the yoke portion; an insulator provided at an axial end of the stator core and having a winding drum portion disposed on the tooth portion; a winding portion in which a plurality of layers are formed by windings in which a conductor wire is wound around the teeth portion via the winding drum portion, When a winding pitch of the conductor wound side by side in the radial direction is P and an outer diameter of the conductor is B, the winding portion has In the radial direction, the winding pitch of the first layer of the winding portion satisfies P>B, an electric motor, wherein the winding pitch of at least one layer of the winding portion from the second layer onward satisfies P≦B.

9. When viewed in a cross section of the winding drum along the radial direction, a surface of the winding drum around which the conducting wire is wound has a flat surface extending along the radial direction, where M is the length of the flat surface in the radial direction and T is the number of turns of the wire wound around the flat surface in the first layer, and (B×T)<M is satisfied.

9. The electric motor according to claim 8.

10. The winding wound in the first layer satisfies P>1.02B.

9. The electric motor according to claim 8.

11. The winding wound in the first layer satisfies 2B>P.

11. The electric motor according to any one of claims 8 to 10.

12. the winding wound in the at least one layer satisfies 0.82B≦P≦B; 9. The electric motor according to claim 8.

13. The windings wound in the second and subsequent layers of the winding portion satisfy P≦B.

9. The electric motor according to claim 8.

14. The outer diameter B of the conductor is the upper limit of the dimensional tolerance of the outer diameter.

9. The electric motor according to claim 8.

15. The conductor has a tensile strength of 460 [N / mm ２ ] is less than 9. The electric motor according to claim 8.

16. the insulator has an annular outer peripheral wall portion attached to the stator core, the conducting wire extends from the winding portion to the outer peripheral wall portion to form a crossover wire, When a first cross-sectional area perpendicular to the longitudinal direction of the winding wound in the first layer is A1 and a second cross-sectional area perpendicular to the longitudinal direction of the jumper wire is A2, (A1 / A2)>0.85 is satisfied.

9. The electric motor according to claim 8.

17. the conducting wire has a conductor and an insulating film covering the conductor, the static friction coefficient of the insulating film is 0.12 or less; 9. The electric motor according to claim 8.

18. The insulator contains glass fibers in an amount of 15% by weight or more and 45% by weight or less.

9. The electric motor according to claim 8.

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