Stator and motor

Abstract

The invention provides a stator and a motor. The stator has a core back, a plurality of teeth, and a coil. The iron core back part is in a ring shape surrounding the central shaft in the circumferential direction. The plurality of teeth are arranged in the circumferential direction so as to extend radially outward from the core back. The coils are respectively wound on the plurality of teeth. Current of any phase of three-phase alternating current flows through the coil. At least a portion of a connecting line connecting a first coil wound around a first tooth among the plurality of teeth and a second coil through which a current of the same phase as the first coil flows is located in a slot formed between any two teeth among the plurality of teeth except the first tooth and a second tooth disposed next to the first tooth. The connecting line is located at the root of the teeth in the groove.

Description

Technical Field

[0001] The present invention relates to a stator and a motor. Background Art

[0002] In the small spindle motor disclosed in Patent Document 1, three-phase stator coils are disposed on a ring-shaped core of a stator.

[0003] Prior art literature

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2002-238197

[0005] In the small spindle motor of Patent Document 1, the three wires forming the three-phase stator coils pass through multiple slots arranged between the stator coils and are drawn out from any slot. This increases the length of the three wires, which in turn increases resistance and copper loss. Summary of the Invention

[0006] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a stator and a motor capable of suppressing an increase in copper loss due to an increase in electrical resistance.

[0007] An exemplary stator of the present invention has an iron core back, a plurality of teeth, and a coil. The iron core back is annular and surrounds a central axis in the circumferential direction. The plurality of teeth are arranged along the circumferential direction, extending radially outward from the iron core back. The coils are respectively wound on the plurality of teeth. A current of any phase of three-phase alternating current flows through the coils. At least a portion of a connecting wire connecting a first coil wound on a first tooth among the plurality of teeth and a second coil through which a current of the same phase as that of the first coil flows is located in a slot formed between any two teeth among the plurality of teeth other than the first tooth and the second tooth arranged next to the first tooth. The connecting wire is located at the root of the tooth in the slot.

[0008] An exemplary motor of the present invention includes the stator, a shaft, and a rotor. The shaft extends along the central axis. The rotor rotates relative to the stator.

[0009] The effects of the present invention are as follows.

[0010] According to the exemplary embodiment of the present invention, it is possible to suppress an increase in copper loss associated with an increase in electrical resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 1 is a diagram illustrating a cross section of the motor 1 according to the exemplary first embodiment along the rotation axis.

[0012] Figure 2 This is a diagram of the stator 10 as viewed from one axial side Z1 .

[0013] Figure 3 It is a plan view showing the stator 10 in a state where the coil 123 is wound.

[0014] Figure 4 It is an enlarged view of two adjacent teeth 122 of the stator 10 .

[0015] Figure 5 1 is a diagram showing a winding method of the coil 123 corresponding to U.

[0016] Figure 6 1 is a diagram showing a winding method of coil 123 corresponding to V.

[0017] Figure 7 1 is a diagram showing a winding method of the coil 123 corresponding to W.

[0018] In the figure: 1—motor, 10—stator, 20—rotor, 30—shaft, 121a—core back, 122, 122A~122M—teeth, 123, 123A~123M—coil, C—circumferential direction, CA, CA1~CA3—conductors, J—center axis, R—radial direction, S, S1~S12—slots, Z—axial direction. DETAILED DESCRIPTION

[0019] Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings. In addition, in the drawings, the same or equivalent parts are marked with the same figure marks, and the description is not repeated. In this specification, for easy understanding, the direction roughly parallel to the rotating shaft of the motor is recorded as axial direction Z, one side of the axial direction Z is recorded as axial one side Z1, and the other side of the axial direction Z is recorded as axial other side Z2. In addition, the radial direction centered on the axial direction Z is recorded as R, and the circumferential direction centered on the axial direction Z is recorded as circumferential direction C. However, the directions are defined only for the convenience of explanation, and except for the cases where the horizontal direction and the vertical direction need to be defined, the orientation of the cooling device involved in the present invention during use is not limited. In addition, in this application, "orthogonal directions" also include roughly orthogonal directions.

[0020] Reference Figure 1 , a motor 1 according to an exemplary first embodiment will be described. Figure 1 1 is a diagram illustrating a cross section of the motor 1 according to the exemplary first embodiment along the rotation axis.

[0021] As an example, the motor 1 is mounted on a drone. Typically, the motor 1 is used as a motor for rotating a propeller of the drone.

[0022] like Figure 1As shown, the motor 1 includes a shaft 30 serving as a rotating axis, a stator 10, a rotor 20, and bearings 24. When the motor 1 is mounted on a drone, the shaft 30 is fixed to the rotor 20, forming the rotating axis of the propeller. The stator 10 is annular in shape. The rotor 20 rotates relative to the stator 10. In this embodiment, the rotor 20 surrounds the radial outer circumference R of the stator 10 and covers one axial side Z1 of the stator 10.

[0023] Specifically, the rotor 20 has a yoke 21 and a plurality of magnets 22. Typically, the yoke 21 is a cylindrical, i.e., annular, iron component that surrounds the outer circumference of the stator 10. A plurality of magnets 22 are arranged along the inner circumferential surface of the yoke 21. Specifically, the plurality of magnets 22 are arranged on the inner circumferential surface of the yoke 21 with the north pole and the south pole alternating along the circumferential direction C. The magnet 22 is, for example, a rectangular permanent magnet. In the embodiment, a plurality of magnets are arranged in an array, but it may also be a single annular magnet with the north pole and the south pole alternating.

[0024] [stator]

[0025] Next, refer to Figure 1 and Figure 2 , a stator 10 according to an exemplary first embodiment will be described. Figure 2 1 is a plan view showing the stator 10 according to the exemplary first embodiment. Figure 2 This is a diagram of the stator 10 as viewed from one axial side Z1 . Figure 2 The stator 10 is shown in a state where the coils 123 are not provided.

[0026] The stator 10 has a stator core 121 and a coil 123. Figure 1 As shown, the stator core 121 is annular and is arranged on the inner side of the magnet 22 in the radial direction R with a gap therebetween. Specifically, the stator core 121 is mounted so as to be rotatable relative to the shaft 30 via the bracket 25 and the bearing 24. For example, the outer diameter of the stator core 121 is 35 [mm] to 40 [mm]. The bracket 25 has a cylindrical barrel 25A located on the inner side of the stator core 121 in the radial direction R, and a cover 25B connected to the barrel 25A and covering the other axial side Z2 of the stator core 121. The outer circumferential surface of the barrel 25A contacts the inner circumferential surface of the stator core 121. The bearing 24 is mounted on the inner circumferential surface of the barrel 25A. That is, the center of the stator core 121 coincides with the center of the barrel 25A. As a result, the center of the stator core 121 roughly coincides with the central axis J of the shaft 30. Therefore, the rotor 20 rotates around the stator 10 together with the shaft 30 , with the shaft 30 serving as an axis.

[0027] like Figure 1 As shown, the stator core 121 is formed by stacking a plurality of core components in the axial direction Z. The core components are formed of electromagnetic steel sheets, for example. Figure 2 As shown, stator core 121 includes core back 121a and twelve teeth 122A to 122M. Hereinafter, teeth 122A to 122M may be referred to as teeth 122. Providing twelve teeth 122 achieves a balance between suppressing cogging torque and ensuring space between teeth 122 for winding coils 123.

[0028] The core back 121a and the teeth 122 are integrally formed. The core back 121a is annularly shaped, surrounding the central axis J of the shaft 30 in the circumferential direction C. The teeth 122 extend outward in the radial direction R from the outer surface of the core back 121a in the radial direction R. The teeth 122A to 122M are arranged sequentially in a clockwise direction C1 at equal intervals along the circumferential direction C when viewed from one axial side Z1.

[0029] Slots S, which serve as gaps between teeth 122 and other components, are formed between teeth 122. Specifically, slot S2 is formed between tooth 122A and tooth 122B. Slot S3 is formed between tooth 122B and tooth 122C. Slot S4 is formed between tooth 122C and tooth 122D. Slot S5 is formed between tooth 122D and tooth 122E. Slot S6 is formed between tooth 122E and tooth 122F. Slot S7 is formed between tooth 122F and tooth 122G. Slot S8 is formed between tooth 122G and tooth 122H. Slot S9 is formed between tooth 122H and tooth 122J. Slot S10 is formed between tooth 122J and tooth 122K. Slot S11 is formed between tooth 122K and tooth 122L. Slot S12 is formed between tooth 122L and tooth 122M. A slot S1 is formed between the tooth 122M and the tooth 122A.

[0030] Next, refer to Figure 3 and Figure 4 , the stator 10 in a state where the coil 123 is wound will be described. Figure 3 It is a plan view showing the stator 10 in a state where the coil 123 is wound. Figure 4 It is an enlarged view of two adjacent teeth 122 of the stator 10 . Figure 4 The tooth 122D and the tooth 122E are representatively shown.

[0031] Coil 123 is attached to teeth 122A through 122M. Specifically, coil 123 is formed by winding a conductive wire CA around each tooth 122. Conductor CA is a cable consisting of a rope-shaped conductor and an insulating coating surrounding the conductor. Hereinafter, the portion of conductor CA not forming coil 123 is sometimes referred to as "extending wire."

[0032] Coils 123 corresponding to any of the three-phase AC are wound around teeth 122A to 122M. In this embodiment, coils 123A, 123B, 123G, and 123H corresponding to phase U of the three-phase AC are respectively arranged on teeth 122A, 122B, 122G, and 122H. In other words, the current of phase U of the three-phase AC flows through coils 123A, 123B, 123G, and 123H. Coils 123A and 123B are arranged adjacent to each other. Coil 123G is arranged on the opposite side of coil 123A across the center axis J. Coil 123H is arranged on the opposite side of coil 123B across the center axis J.

[0033] Coils 123C, 123D, 123J, and 123K are disposed on teeth 122C, 122D, 122J, and 122K, respectively, corresponding to phase V of the three-phase AC. Current for phase V of the three-phase AC flows through coils 123C, 123D, 123J, and 123K. Coils 123C and 123D are disposed adjacent to each other. Coil 123J is disposed on the opposite side of coil 123C across the central axis J. Coil 123K is disposed on the opposite side of coil 123D across the central axis J.

[0034] Coils 123E, 123F, 123L, and 123M, corresponding to phase W of the three-phase AC, are disposed on teeth 122E, 122F, 122L, and 122M, respectively. Current for phase W of the three-phase AC flows through coils 123E, 123F, 123L, and 123M. Coils 123E and 123F are disposed adjacent to each other. Coil 123L is disposed on the opposite side of coil 123E across the central axis J. Coil 123M is disposed on the opposite side of coil 123F across the central axis J.

[0035] like Figure 4 As shown, the tooth 122 includes a columnar portion 122a and a pair of protrusions 122b. The columnar portion 122a has a columnar shape and extends outward in the radial direction R from the core back portion 121a. Hereinafter, in the radial direction R, the core back portion 121a side of the tooth 122 and the columnar portion 122a is referred to as the root side, and the side opposite the root side is referred to as the tip side. The pair of protrusions 122b protrude from the tip side of the columnar portion 122a in the clockwise direction C1 and the counterclockwise direction C2 of the circumferential direction C, respectively.

[0036] The coil 123 is provided on the column 122a. Specifically, the coil 123 is formed by winding the conductive wire CA around the column 122a. In this embodiment, the conductive wire CA is first wound from the root side of the column 122a toward the front end side, and when the conductive wire CA reaches the protrusion 122b, it is further wound from the outside of the conductive wire CA wound around the column 122a toward the root side. Figure 4 , the winding order of the conductive wire CA is represented by numbers 1 to 10. The following description will be made taking the case where the number of turns of the conductive wire CA per coil 123 is 10 as a representative example.

[0037] In this embodiment, the end of the coil 123 is located outside the center of the tooth 122 in the radial direction R. Since the intervals between the slots S on the tip side of the tooth 122 are wider than the intervals between the slots S on the root side of the tooth 210, the number of turns of the coil 123 can be easily increased by arranging the end of the coil 123 further to the tip side.

[0038] For example, the wire diameter of the conductor CA is 0.5 mm to 0.9 mm. This improves the heat dissipation of the conductor CA and suppresses the increase in resistance associated with temperature rise. As a result, the motor 1 including the stator 10 can achieve good torque characteristics in the high-speed range.

[0039] Furthermore, by using the conductive wire CA having a wire diameter of 0.5 mm to 0.9 mm, good torque characteristics can be obtained even when the coil 123 is formed by the conductive wire CA wound around the teeth 122 with 10 turns or less.

[0040] As a result, since the coil 123 is formed with a small number of turns, the number of conductive wires CA wound around the teeth can be reduced to two or less layers. Therefore, the volume of the coil 123 is reduced, and the stator 10 can be formed more compactly.

[0041] In this embodiment, the number of turns of the conductive wire CA in each coil 123 is not particularly limited. For example, the number of turns of the conductive wire CA in each coil 123 may be 20 or less. By increasing the number of turns of the coil 123 to more than 10, the magnetic force of the coil 123 is increased, further increasing the torque of the rotor 20.

[0042] In this embodiment, coils 123A, 123B, 123G, and 123H corresponding to the U phase are formed from a single conductor CA1. Coils 123A, 123B, 123G, and 123H corresponding to the U phase are formed from a single conductor CA1. Coils 123C, 123D, 123J, and 123K corresponding to the V phase are formed from a single conductor CA2. Coils 123E, 123F, 123L, and 123M corresponding to the W phase are formed from a single conductor CA3.

[0043] The following description uses the U-phase as a representative example. The V-phase and W-phase are similar to the U-phase. For example, when coils 123A, 123B, 123G, and 123H are formed from a single conductive wire CA1, when transferring conductive wire CA1 from coil 123B to coil 123G, it is necessary to avoid region E0 located radially inward of the inner circumferential surface of stator core 121.

[0044] Therefore, in this embodiment, the conductive wire CA1 is transferred from coil 123B to coil 123G via one or more slots S. Typically, the conductive wire CA1 passes through any slot S5 to S12 formed between any two teeth 122 among teeth 122D to 122M, excluding tooth 122B on which coil 123B is located and teeth 122A and 122C located adjacent to tooth 122B. In this case, tooth 122B on which coil 123B is located is an example of a first tooth. Teeth 122A and 122C located on either side of tooth 122B are each an example of a second tooth. Tooth 122G on which coil 123G, in phase with coil 123B, is located is an example of a third tooth.

[0045] Thus, in addition to region E0, conductive wire CA1 can also avoid region E1, which is a predetermined range extending from the inner circumferential surface of core back 121a to the outer side in radial direction R. As a result, the mounting jig used to attach cylindrical portion 25A to stator core 121 can be installed in region E1, thereby reducing the possibility of contact between the mounting jig and coil 123. For example, region E1 preferably occupies at least half of the width of core back 121a in radial direction R. Furthermore, region E1 more preferably occupies at least two-thirds of the width of core back 121a in radial direction R.

[0046] For example, Figure 3 and Figure 4 As shown, the conductive wire CA1 forming the coil 123B and the coil 123G corresponding to U passes through a slot S5 formed between the tooth 122D provided with the coil 123D corresponding to V and the tooth 122E provided with the coil 123E corresponding to W.

[0047] Specifically, the conductor CA1 extends from the position where the winding of the coil 123B ends in slot S2 along the surface on the other axial side Z2 of the stator core 121 to slot S5, extends through slot S5 to the surface on the one axial side Z1 of the stator core 121, and extends from slot S5 along the surface on the one axial side Z1 of the stator core 121 to the position where the winding of the coil 123G ends in slot S7. Figure 3 and Figure 4 In FIG. 1 , the conductor CA1 is indicated by a solid line on a surface on one axial side Z1 , and the conductor CA1 is indicated by a dotted line on a surface on the other axial side Z2 .

[0048] By passing only through slot S5 from coil 123B to coil 123G, conductor CA1 minimizes movement between the two surfaces of stator core 121 in the axial direction Z, allowing conductor CA1 to be transferred from coil 123B to coil 123G over a shorter distance. Consequently, stator 10, equipped with multiple coils 123, can be compactly constructed without the use of insulators. Furthermore, since the overall resistance of coils 123 is reduced, stator core 121 exhibits excellent magnetic properties. As a result, motor 1 equipped with stator core 121 achieves a high-efficiency motor with reduced copper loss, excellent torque characteristics in the high-speed range, and reduced losses.

[0049] Furthermore, the conductive wire CA1 can be connected to the coil 123G disposed opposite to the coil 123B in the radial direction R, specifically, the coil 123G adjacent to the coil 123H located farthest from the coil 123B, only via the slot S5 . This allows the conductive wire CA1 to be further shortened.

[0050] In this case, conductor CA1 is positioned at the base of tooth 122E in slot S5, replacing conductor CA3, which forms coil 123E. Positioning conductor CA1 at the base of tooth 122E prevents obstruction of coil 123E and allows conductor CA1 to be transferred from coil 123B to coil 123G over a shorter distance. Furthermore, when conductor CA1 passes through slot S5, it can be positioned at the base of tooth 122D, rather than at the base of tooth 122E.

[0051] Next, refer to Figures 5 to 7 , the winding methods of the coils 123 corresponding to the U phase, V phase and W phase respectively are described. Figure 5 1 is a diagram showing a winding method of the coil 123 corresponding to U. Figure 6 1 is a diagram showing a winding method of coil 123 corresponding to V. Figure 7 1 is a diagram showing a winding method of the coil 123 corresponding to W.

[0052] like Figure 5 As shown, the winding start position US of the conductor CA1 forming the coils 123A, 123B, 123G, and 123H corresponding to U is on the other axial side Z2 of the slot S10. The conductor CA1 first passes through the slot S10 and extends along the surface on the one axial side Z1 to the slot S12. Then, the conductor CA1 passes through the slot S12 and extends along the surface on the other axial side Z2 of the stator core 121 to the slot S1. Next, the conductor CA1 is wound around the tooth 122A ( Figure 3) to form the coil 123A. Next, the conductor CA1 extends from the winding end portion of the coil 123A in the slot S2 along the surface on the other axial side Z2 of the stator core 121 to the slot S3. Next, the conductor CA1 is wound around the tooth 122B ( Figure 3 ) to form the coil 123B. Next, the conductor CA1 extends from the winding end portion of the coil 123B in slot S2 along the surface on the other axial side Z2 of the stator core 121 to slot S5. Next, the conductor CA1 passes through slot S5 and extends along the surface on one axial side Z1 of the stator core 121 to slot S7. Next, the conductor CA1 passes through slot S7 and extends along the surface on the other axial side Z2 to slot S8. Next, the conductor CA1 is wound around the tooth 122G ( located next to slot S8). Figure 3 ) to form the coil 123G. Next, the conductor CA1 extends from the winding end portion of the coil 123G in the slot S7 along the surface on the other axial side Z2 of the stator core 121 to the slot S8. Next, the conductor CA1 is wound around the tooth 122H ( Figure 3 ) to form the coil 123H. The conductive wire CA1 is drawn out from the winding end portion of the coil 123H in the slot S9 to the other axial side Z2. That is, the winding end portion of the coil 123H in the slot S9 is the position UE where the winding of the conductive wire CA1 ends.

[0053] like Figure 6 As shown, the winding start position VS of the conductor CA2 forming the coils 123C, 123D, 123J, and 123K corresponding to V is on the other axial side Z2 of the slot S9. The conductor CA2 is first wound around the tooth 122J ( Figure 3 ) to form the coil 123J. Next, the conductor CA2 extends from the winding end portion of the coil 123J in the slot S10 along the surface on the other axial side Z2 of the stator core 121 to the slot S11. Next, the conductor CA2 is wound around the tooth 122K ( Figure 3 ) to form the coil 123K. Next, the conductor CA2 extends from the winding end portion of the coil 123K in the slot S10 along the surface on the other axial side Z2 of the stator core 121 to the slot S1. Next, the conductor CA2 passes through the slot S1 and extends along the surface on the one axial side Z1 of the stator core 121 to the slot S3. Next, the conductor CA2 is wound around the tooth 122C ( Figure 3 ) to form the coil 123C. Next, the conductor CA2 extends from the winding end portion of the coil 123C in the slot S3 along the surface on the other axial side Z2 of the stator core 121 to the slot S4. Next, the conductor CA2 is wound around the tooth 122D ( Figure 3) to form coil 123D. Then, the conductive wire CA2 extends from the winding end of coil 123G in slot S4 along the surface on one axial side Z1 of stator core 121 to slot S7. Then, the conductive wire CA2 passes through slot S7 and is led out to the other axial side Z2. That is, the winding end point VE of the conductive wire CA2 is located in slot S7.

[0054] like Figure 7 As shown, the winding start position WS of the conductor CA3 forming the coils 123E, 123F, 123L, and 123M corresponding to W is on the other axial side Z2 of the slot S8. The conductor CA3 first passes through the slot S8 and extends along the surface on the axial side Z1 of the stator core 121 to the slot S7. The conductor CA3 is then wound around the tooth 122F ( Figure 3 ) to form the coil 123F. Then, the conductor CA3 extends from the winding end portion of the coil 123F in the slot S6 along the surface on the other axial side Z2 of the stator core 121 to the slot S5. Then, the conductor CA3 is wound around the tooth 122E ( Figure 3 ) to form the coil 123E. Next, the conductor CA3 extends from the winding end portion of the coil 123E in the slot S6 along the surface on the other axial side Z2 of the stator core 121 to the slot S12. Next, the conductor CA3 is wound around the tooth 122L ( Figure 3 ) to form the coil 123L. Next, the conductor CA3 extends from the winding end portion of the coil 123L in the slot S11 along the surface on the other axial side Z2 of the stator core 121 to the slot S12. Next, the conductor CA3 is wound around the tooth 122M ( Figure 3 ) to form coil 123M. Then, the conductive wire CA3 extends from the winding end point of coil 123M in slot S1 along the surface on the other axial side Z2 of stator core 121 to slot S12. Then, the conductive wire CA3 passes through slot S12 and extends along the surface on one axial side Z1 of stator core 121 to slot S11. Then, the conductive wire CA3 passes through slot S11 and is led out to the other axial side Z2. That is, the winding end point WE of conductive wire CA3 is located in slot S11.

[0055] Figure 3 and Figures 4 to 7The diagram shows the winding start position US of the conductor CA1, the winding end position UE of the conductor CA1, the winding start position VS of the conductor CA2, the winding end position VE of the conductor CA2, the winding start position WS of the conductor CA3, and the winding end position WE of the conductor CA3. In this embodiment, the winding start position of at least one of the conductors CA1, CA2, and CA3 is located in a slot S other than the slot S where the winding start position or winding end position of the other two conductors CA is located. Furthermore, the winding end position of at least one of the conductors CA1, CA2, and CA3 is located in a slot S other than the slot S where the winding start position or winding end position of the other two conductors CA is located.

[0056] Typically, the winding start position of the wire CA that is wound last among the wires CA1, the wire CA2, and the wire CA3 is located in a slot S other than the slot S where the winding start positions or winding end positions of the other two wires CA are located, and the winding end position is located in a slot S other than the slot S where the winding start positions or winding end positions of the other two wires CA are located.

[0057] As a result, there are two or fewer "connecting wires" located in each slot S. By limiting the number of "connecting wires" extending from each slot S to two or fewer, the "connecting wires" are not biased toward a specific slot. This makes it easier to attach the stator 10 to the rotor 20 and shaft 30.

[0058] The "connection wires" extend from the aligned slots S7 to S11. The slots S where the "connection wires" extend are offset in a portion of the circumferential direction C. This reduces the space required for connecting the "connection wires" to wiring outside the motor 1.

[0059] In this embodiment, the plurality of coils 123 corresponding to the same coil are formed from a single conductive wire CA. However, the present invention is not limited thereto. Alternatively, the plurality of coils 123 may be formed from different conductive wires CA, and the coils 123 may be connected to each other via the different conductive wires CA. In this case, the conductive wire CA connecting the coils 123 is referred to as a "connecting wire."

[0060] In this embodiment, the number of teeth 122 arranged on the stator core 121 and the phase arrangement of the coils 123 arranged on the teeth 122 are not particularly limited. Specifically, the number of teeth 122 can be six, nine, or fifteen or more. Furthermore, the coils 123 can be arranged in alternating three-phase configurations, or groups of multiple coils 123 corresponding to one phase can be arranged sequentially along the circumferential direction C.

[0061] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the above-described embodiments and can be implemented in various ways without departing from the scope of the present invention. In addition, the multiple components disclosed in the above-described embodiments can be appropriately modified. For example, a component of all the components shown in a certain embodiment can be added to the components of another embodiment, or some components of all the components shown in a certain embodiment can be deleted from the embodiment.

[0062] In addition, in order to facilitate understanding of the present invention, the drawings are schematically illustrated with the various components as the main body. To facilitate the preparation of the drawings, the thickness, length, number, spacing, etc. of the various components shown in the drawings may sometimes differ from the actual ones. In addition, the structure of the various components shown in the above embodiment is an example and is not particularly limited. Various changes can of course be made within the scope that does not substantially deviate from the effects of the present invention.

[0063] Furthermore, the present technology can adopt the following structures.

[0064] (1) A stator having:

[0065] an annular core back circumferentially surrounding the central axis;

[0066] a plurality of teeth arranged circumferentially so as to extend radially outward from the core back; and

[0067] Coils are wound around the plurality of teeth,

[0068] In the above coil, the current flowing through any phase of the three-phase AC,

[0069] At least a portion of a connecting wire connecting a first coil wound around a first tooth among the plurality of teeth and a second coil through which a current in phase with that of the first coil flows is located in a slot formed between any two teeth among the plurality of teeth other than the first tooth and a second tooth arranged adjacent to the first tooth.

[0070] The connecting wire is located at the root of the tooth in the groove.

[0071] (2) The stator according to (1), wherein the jumper wire is routed so as to avoid an area within a predetermined range from the inner peripheral surface of the core back to the outer side in the radial direction.

[0072] (3) The stator according to (1) or (2), wherein the third tooth on which the second coil is arranged and the first tooth are arranged to face each other in the radial direction.

[0073] (4) The stator according to any one of (1) to (3), wherein twelve teeth are provided.

[0074] (5) The stator according to any one of (1) to (4), wherein the end portion of the coil is located outside the center of the tooth in the radial direction.

[0075] (6) The stator according to any one of (1) to (5), wherein the coil is wound around the teeth in two layers or less.

[0076] (7) The stator according to any one of (1) to (6), wherein the coil has a number of turns of 10 or less.

[0077] (8) The stator according to any one of (1) to (7), wherein the number of the connecting wires located in the slots is two or less.

[0078] (9) A motor having:

[0079] The stator according to any one of (1) to (8);

[0080] an axis extending along the central axis; and

[0081] A rotor that rotates relative to the stator.

[0082] (10) The motor according to (9), wherein the rotor surrounds the radial outer periphery of the stator.

[0083] The industrial applicability is as follows.

[0084] The present invention can be used in the field of motors.

Claims

1. A stator, characterized in that: have: an annular core back circumferentially surrounding the central axis; a plurality of teeth arranged along the circumferential direction so as to extend radially outward from the core back; and Coils are wound around the plurality of teeth, In the above coil, the current flowing through any phase of the three-phase AC, At least a portion of a connecting wire connecting a first coil wound around a first tooth among the plurality of teeth and a second coil through which a current in phase with that of the first coil flows is located in a slot formed between any two teeth among the plurality of teeth other than the first tooth and a second tooth arranged adjacent to the first tooth. The connecting wire is located at the root of the tooth in the groove.

2. The stator according to claim 1, characterized in that The jumper wire is routed so as to avoid an area within a predetermined range from the inner peripheral surface of the core back to the outer side in the radial direction.

3. The stator according to claim 1 or 2, characterized in that: The third tooth on which the second coil is arranged and the first tooth are arranged at positions facing each other in the radial direction.

4. The stator according to claim 3, characterized in that Twelve of the above-mentioned teeth are provided.

5. The stator according to claim 1 or 2, characterized in that: The end portion of the coil is located outside the center of the tooth in the radial direction.

6. The stator according to claim 5, characterized in that The coil is wound around the teeth in two or fewer layers.

7. The stator according to claim 5, characterized in that The coil has a number of turns of 20 or less.

8. The stator according to claim 1 or 2, characterized in that: There are no more than two connecting wires located in the groove.

9. A motor, characterized in that: have: The stator according to claim 1 or 2; an axis extending along the central axis; and A rotor that rotates relative to the stator.

10. The motor according to claim 9, characterized in that The rotor surrounds the radial outer periphery of the stator.

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