Motor

Abstract

The purpose of the present disclosure is to provide a motor in which loss can be further reduced. A rotor provided to a motor according to the present disclosure has a columnar rotor yoke and a plurality of magnets. The plurality of magnets are positioned in the side surface of the rotor yoke along the circumferential direction of the rotor yoke. A stator has a cylindrical stator yoke, a plurality of teeth, and a plurality of windings. The plurality of teeth are located on the inner circumferential surface of the stator yoke and protrude from a plurality of positions in the circumferential direction of the rotor yoke toward a rotating shaft of the rotor. The plurality of windings (34) are respectively wound around the plurality of teeth. Each of the plurality of windings (34) is configured by winding numerous straight-angle wires (40) and has a plurality of layers (L1 to L11) that overlap one another in the protrusion direction of the corresponding tooth from among the plurality of teeth. Each of the plurality of windings (34) is provided with a notch section (41) in one or more of the plurality of layers (L1 to L11), including the layer (L1) that is closest to the rotor.

Description

motor

[0001] The present disclosure relates to a motor, and more particularly to a motor including a rotor on which magnets are arranged and a stator on which windings are wound.

[0002] Patent Document 1 discloses a rotating electric machine including a stator and a rotor disposed inside the stator. The stator has a stator core in which multiple teeth protrude radially inward from a circular annular yoke at intervals in the circumferential direction, and multiple concentrated winding coils with wire wound around each tooth.

[0003] In such rotating electric machines, leakage flux emitted from the rotor magnet interlinks with the windings, generating eddy currents and resulting in eddy current loss. In the rotating electric machine described in Patent Document 1, recessed shapes are provided in the stator teeth to reduce the magnetic flux interlinking with the windings and thereby reduce eddy current loss.

[0004] In the rotating electric machine (motor) described in Patent Document 1, the teeth of the stator are provided with a concave shape in order to reduce eddy current loss, which could increase losses generated in the motor due to increased iron loss.

[0005] Japanese Patent Application Laid-Open No. 2017-77046

[0006] An object of the present disclosure is to provide a motor that can further reduce losses.

[0007] A motor according to one aspect of the present disclosure includes a rotor and a stator. The rotor includes a cylindrical rotor yoke having a rotation axis centered on its axis, and a plurality of magnets arranged on the side of the rotor yoke along the circumferential direction of the rotor yoke. The stator includes a cylindrical stator yoke arranged concentrically with the rotor, a plurality of teeth, and a plurality of windings. The teeth protrude from the inner peripheral surface of the stator yoke toward the rotation axis from a plurality of positions along the circumferential direction of the rotor yoke. The windings are wound around the teeth, respectively. Each of the windings is formed by winding a rectangular wire in multiple layers, and includes multiple layers that overlap in the direction in which corresponding ones of the teeth protrude. Each of the windings includes a notch in one or more layers, including the layer closest to the rotor.

[0008] FIG. 1 is a perspective view of a motor according to an embodiment of the present disclosure. FIG. 2 is a top view of the motor. FIG. 3 is a cross-sectional view of the motor taken along line A-A in FIG. 2. FIG. 4 is a perspective view of a portion where a stator and a rotor provided in the motor face each other. FIG. 5 is a front view of windings provided in the motor. FIG. 6 is a perspective view of windings provided in the motor. FIG. 7 is a perspective view of windings provided in a motor of Modification 1. FIG. 8 is a perspective view of windings provided in a motor of Modification 1. FIG. 9 is a perspective view of windings provided in a motor of Modification 1. FIG. 10 is a perspective view of windings provided in a motor of Modification 2. FIG. 11 is a perspective view of windings provided in a motor of Modification 3. FIG. 12 is a perspective view of windings provided in a motor of Modification 4. FIG. 13 is a perspective view of windings provided in a motor of Modification 5. FIG. 14 is a perspective view of windings provided in a motor of Modification 5. FIG. 15 is a perspective view of windings provided in a motor of Modification 6.

[0009] (Embodiments) Motors according to embodiments of the present disclosure will be described in detail below with reference to the drawings. However, the configurations described below are merely examples of the present disclosure, and the present disclosure is not limited to the following embodiments. Various modifications other than these embodiments are possible depending on the design, etc., as long as they do not deviate from the technical concept of the present disclosure. Furthermore, the figures described in the following embodiments are schematic diagrams, and the ratios of the sizes and thicknesses of the components in the figures do not necessarily reflect the actual dimensional ratios.

[0010] (1) Overview Fig. 1 is a perspective view of a main part of a motor 1 according to an embodiment of the present disclosure, Fig. 2 is a plan view of the main part of the motor 1, and Fig. 3 is a cross-sectional view taken along line AA in Fig. 2.

[0011] The motor 1 of this embodiment includes a rotor 2 and a stator 3 .

[0012] The rotor 2 has a cylindrical rotor yoke 22 and a plurality of magnets 23 .

[0013] The rotor yoke 22 has a rotation axis 21 whose center of rotation is the axis Ax1.

[0014] The plurality of magnets 23 are arranged on the side surface of the rotor yoke 22 along the circumferential direction of the rotor yoke 22 .

[0015] The stator 3 has a cylindrical stator yoke 32 , a plurality of teeth 33 , and a plurality of windings 34 .

[0016] The stator yoke 32 is disposed concentrically with the rotor 2 .

[0017] The teeth 33 protrude from the inner peripheral surface of the stator yoke 32 toward the rotary shaft 21 at a plurality of positions in the circumferential direction of the rotor yoke 22 .

[0018] The plurality of windings 34 are wound around the plurality of teeth 33, respectively.

[0019] Each of the multiple windings 34 is constructed by winding a flat wire 40 in multiple layers, and has multiple (for example, 11 in Figure 4) layers L1 to L11 that overlap in the protruding direction of the corresponding tooth 33 among the multiple teeth 33.

[0020] In each of the plurality of windings 34, a notch 41 (see FIGS. 5 and 6) is provided in one or more layers, including the layer L1 closest to the rotor 2, among the plurality of layers L1 to L11.

[0021] Here, the "axial direction" of the rotating shaft 21 is the direction in which the rotating shaft 21 extends and coincides with the axis Ax1 of the rotating shaft 21. Furthermore, on a plane perpendicular to the axis Ax1, the direction perpendicular to the extension direction of the axis Ax1 and extending radially from the axis Ax1 of the rotating shaft 21 is defined as the "radial direction" of the rotor yoke 22, and the direction in which the rotor yoke 22 revolves around the axis Ax1 of the rotating shaft 21, i.e., the direction along the peripheral surface of the rotor yoke 22, is defined as the "circumferential direction" of the rotor yoke 22. Note that "orthogonal" in this disclosure does not only refer to a state in which the angle between two elements is exactly 90 degrees, but also includes a state in which the two elements are approximately orthogonal within a certain margin of error. In other words, the angle between the two orthogonal elements is within a certain margin of error (for example, 10 degrees or less) from 90 degrees. Each of the plurality of windings 34 has a plurality of layers L1 to L11 of wire material 40. Of the plurality of layers L1 to L11 of wire material 40, the layer closest to the rotor 2 may be referred to as the first layer L1, and the nth layer counting from the rotor 2 side may be referred to as the nth layer Ln, where n is a positive integer. Furthermore, "windings wound around teeth" may mean, for example, that the windings are wound around insulating insulators provided on the teeth, or that the windings are wound directly around teeth whose surfaces have been subjected to an insulating treatment.

[0022] In the motor 1 of this embodiment, a notch 41 is provided in one or more layers of the multiple layers L1 to L11 of the wire 40 of the winding 34, including the layer closest to the rotor 2 (first layer L1).

[0023] In each of the multiple windings 34, leakage magnetic flux from the magnets 23 of the rotor 2 is likely to link with one or more layers, including the first layer L1, which is closest to the rotor 2. In this embodiment, the notches 41 are provided in one or more layers, including the first layer L1, in each of the multiple windings 34. This increases the distance between the windings 34 and the magnets 23 compared to when the notches 41 are not provided. This reduces leakage magnetic flux linking with the wire 40 of the windings 34 and reduces eddy current loss in the motor 1. Furthermore, unlike the rotating electric machine described in Patent Document 1, there is no need to provide recesses in the teeth 33. This suppresses an increase in iron loss in the teeth 33, thereby providing a motor 1 that can further reduce losses overall. Another advantage is that the notches 41 are formed in a portion of one or more layers, including the first layer L1, among the multiple layers L1 to L11 of the windings 34. This suppresses an increase in DC resistance of the wire 40 that constitutes the windings 34.

[0024] (2) Details The motor 1 according to this embodiment will be described in detail below with reference to FIGS. 1 to 6. FIG.

[0025] The motor 1 according to this embodiment is, for example, an inner rotor brushless motor in which a rotor is disposed inside a stator 3. This motor 1 is driven by, for example, three-phase AC current (U phase, V phase, and W phase) that are 120 degrees out of phase with each other.

[0026] The motor 1 includes a rotor 2, a stator 3, and a casing (not shown) that houses the rotor 2 and the stator 3.

[0027] (2.1) Rotor As described above, the rotor 2 includes the rotor yoke 22 and a plurality of magnets 23.

[0028] The rotor yoke 22 is cylindrical and centered on the axis Ax1, with the axial dimension being smaller than the radial dimension. The rotor yoke 22 is formed, for example, by stacking multiple non-oriented magnetic steel plates in the axial direction. The rotor yoke 22 may also be formed of iron, silicon steel, permalloy, ferrite, or the like.

[0029] A circular hole is provided in the center of rotor yoke 22. Rotating shaft 21 is inserted into the central hole of rotor yoke 22, and rotor yoke 22 is attached to the axial middle portion of rotating shaft 21. Rotor yoke 22 is fixed to rotating shaft 21, and rotates together with rotating shaft 21 about axis Ax1.

[0030] The rotor 2 is, for example, a surface magnet type rotor. A plurality of magnets 23 are attached to the side surface of the rotor yoke 22 so as to be arranged at equal intervals in the circumferential direction of the rotor yoke 22. In this embodiment, for example, ten magnets 23 are attached at equal intervals to the circumferential surface of the rotor yoke 22.

[0031] Each of the plurality of magnets 23 is a permanent magnet, such as a neodymium magnet, formed in a rectangular parallelepiped shape. The plurality of magnets 23 are arranged on the side surfaces of the rotor yoke 22 so that their magnetic poles are arranged alternately in the circumferential direction of the rotor yoke 22.

[0032] (2.2) Stator The stator 3 has a stator core 31 and a plurality of windings 34 .

[0033] The stator core 31 is configured by combining the above-mentioned stator yoke 32 with a plurality of teeth 33 .

[0034] The stator yoke 32 is formed in a cylindrical shape. The stator yoke 32 is formed, for example, by stacking multiple non-oriented magnetic steel plates in the axial direction of the rotating shaft 21. The stator yoke 32 is disposed concentrically with the rotor 2. In other words, the central axis of the cylindrical stator yoke 32 coincides with the axis Ax1 of the rotating shaft 21 of the rotor yoke 22.

[0035] A plurality of teeth 33 protrudes toward the rotating shaft 21 from the inner peripheral surface of the stator yoke 32 so as to be arranged at equal intervals in the circumferential direction of the rotor yoke 22. Each of the plurality of teeth 33 is fixed to the stator yoke 32, for example, by fitting a portion of the tooth 33 into a groove provided in the stator yoke 32.

[0036] The teeth 33 are arranged at equal intervals in the circumferential direction of the rotor yoke 22, and each of the teeth 33 faces the rotor yoke 22 in the radial direction. A winding 34 is wound around each of the teeth 33 via an insulating insulator. When the rotor 2 is arranged inside the stator 3, each of the teeth 33 faces the outer circumferential surface of the rotor 2 with a gap therebetween.

[0037] In this embodiment, twelve teeth 33, for example, are arranged at equal intervals on the inner circumferential surface of the stator yoke 32, and a winding 34 is wound around each of the twelve teeth 33. The twelve windings 34 are divided into three groups corresponding to the three phases. Each group includes four windings 34 arranged at equal intervals in the circumferential direction of the rotor yoke 22.

[0038] Fig. 4 is a perspective view of the main part, showing a state in which one tooth 33 of the stator 3 faces one magnet 23 attached to the rotor yoke 22. Fig. 5 is a front view of only the winding 34, and Fig. 6 is a perspective view of only the winding 34.

[0039] The windings 34 are edgewise windings formed by winding rectangular wire material (so-called rectangular wire) 40 made of, for example, copper or a copper alloy in multiple layers. Each of the plurality of windings 34 has a plurality of (e.g., eleven) layers L1 to L11 that overlap in the direction in which a corresponding one of the plurality of teeth 33 protrudes. Both ends (first end 40A and second end 40B) of the wire material 40 that constitutes the windings 34 are drawn out in one direction, for example, parallel to the axial direction of the rotating shaft 21.

[0040] In each of the multiple windings 34, the portions located outside the rotor yoke 22 when viewed radially from the rotor yoke 22 (in other words, when viewed from a plane in the radial direction of the rotor yoke 22) are referred to as coil end portions E1 and E2. In other words, when viewed from a plane in the radial direction of the rotor yoke 22, the portions of the windings 34 that do not overlap with the rotor yoke 22 are referred to as coil end portions E1 and E2. The coil end portions E1 and E2 are portions that do not contribute to the generation of an effective magnetic field that creates a rotating magnetic field that rotates the rotor 2. In this embodiment, a notch 41 is provided in the coil end portion E1 of one of the coil end portions E1 and E2 on either side of the rotor yoke 22 (the lower side in FIG. 5 ). In other words, in one or more layers of the windings 34, the notch 41 is provided in the coil end portion E1 located outside the rotor yoke 22 when viewed from a plane in the radial direction of the rotor yoke 22.

[0041] Here, with the rotor 2 in the rotational position shown in FIG. 2 , we will explain the eddy current reduction effect of providing the cutout 41, focusing on the magnet 23A, which faces two adjacent teeth 33A and 33B, among the multiple magnets 23 provided on the rotor yoke 22. When the magnet 23A faces two adjacent teeth 33A and 33B, magnetic flux B1 emanating from the magnet 23A is swept by the tooth 33A, passes through the stator yoke 32, and returns to the magnet 23A from the adjacent tooth 33B. This flow of magnetic flux B1 is called the main magnetic flux and is used to rotate the rotor 2 and output torque. However, the magnetic flux emanating from the magnet 23A is not limited to the main magnetic flux; there is also leakage magnetic flux that leaks outside the stator core 31. The leakage magnetic flux is mainly generated in the air gap between the rotor 2 and the stator 3. When this leakage magnetic flux interlinks with the winding 34 wound around the tooth 33A or 33B, an eddy current is generated in the winding 34, and an eddy current loss corresponding to this current occurs. This eddy current loss becomes heat, which may cause a temperature rise in the winding 34 and a decrease in the efficiency of the motor 1.

[0042] In the motor 1 of this embodiment, the wire 40 of the winding 34 is rectangular wire, which improves the space factor and reduces the DC resistance of the winding 34. However, when the wire 40 is rectangular wire, the cross-sectional area through which leakage flux intersects is larger than when the wire 40 is twisted or round, which may increase eddy currents. Therefore, in this embodiment, as shown in Figures 5 and 6, notches 41 are provided in the winding 34 at locations where leakage flux concentrates, such as the coil end E1 of the winding 34. This allows the length of the gap between the magnet 23 and the winding 34 to be longer than when the notch 41 is not provided. This reduces the leakage flux interlinking the winding 34 and reduces eddy current loss. Note that the notch 41 is provided in the coil end E1, but it may also be provided in the coil end E2 or both coil ends E1 and E2.

[0043] Furthermore, in this embodiment, the notch 41 is provided only in a portion of the winding 34 where leakage magnetic flux concentrates, for example, in the layer (first layer L1) of the multiple layers L1 to L11 that is closest to the rotor 2. By providing the notch 41 in the first layer L1 of the winding 34, the length of the air gap between the magnet 23 and the winding 34 is increased, thereby reducing the leakage magnetic flux that interlinks with the winding 34, which in turn suppresses the generation of eddy currents and therefore reduces eddy current loss. The notch 41 may be formed in the winding 34 by stamping or cutting, or any appropriate method may be used.

[0044] In this embodiment, the notches 41 are provided in the first layer L1 of the winding 34 at the end facing the teeth 33. In other words, it is preferable that the notches 41 are provided in one or more layers of the winding 34 at the end facing the teeth 33. By providing the notches 41 in the one or more layers of the winding 34 at locations where leakage flux is likely to concentrate, it is possible to reduce the leakage flux linking the winding 34 and reduce eddy current loss.

[0045] In addition, the notch 41 may be provided at the end opposite to the end facing the tooth 33 in one or more layers of the winding 34, and the position at which the notch 41 is provided can be changed as appropriate.

[0046] Furthermore, in this embodiment, it is not essential that the notch 41 be provided in one or more layers, including the layer L1 closest to the rotor 2, of all of the multiple windings 34 wound around the multiple teeth 33. The notch 41 may be provided in one or more layers, including the layer L1 closest to the rotor 2, of some of the multiple windings 34 wound around the multiple teeth 33.

[0047] (3) Modifications The above embodiment is merely one of various embodiments of the present disclosure. The above embodiment can be modified in various ways depending on the design, etc., as long as the object of the present disclosure can be achieved.

[0048] Modifications of the above embodiment are listed below. The modifications described below can be applied in appropriate combinations.

[0049] (3.1) Modification 1 The winding 34A of the motor 1 according to Modification 1 of the above embodiment will be described with reference to Figures 7 to 9. Note that, apart from the winding 34A, the motor 1 has the same configuration as the motor 1 of the above embodiment, and therefore the same reference numerals are used for the common configuration and a description thereof will be omitted.

[0050] In the winding 34 of the above embodiment, the notch 41 is provided only in the first layer L1, but in the winding 34A of the first modification, the notch 41 is provided in multiple layers including the first layer L1.

[0051] Fig. 7 is a perspective view of a winding 34A included in the motor 1 of Modification 1. In the winding 34A shown in Fig. 7, a notch 41 is provided in two layers, a first layer L1 and a second layer L2, at the same position when viewed from the radial direction of the rotor yoke 22.

[0052] In this way, by providing notches 41 in multiple layers of the winding 34A, including the first layer L1, the leakage magnetic flux linking the winding 34A can be further reduced, and eddy current loss can be further reduced.

[0053] The number of layers in which the notches 41 are provided among the multiple layers of the winding 34A can be changed as appropriate.

[0054] For example, as shown in Fig. 8, the three layers, from the first layer L1 to the third layer L3 of the winding 34A, may have the notches 41 at the same position as viewed from the radial direction of the rotor yoke 22. Alternatively, as shown in Fig. 9, the notches 41 may be at the same position as viewed from the radial direction of the rotor yoke 22 in all of the layers L1 to L11 of the winding 34A. When the notches 41 are provided in each of the multiple layers, it is preferable that the multiple notches 41 provided in each of the multiple layers be at the same position as viewed from the radial direction of the rotor yoke 22.

[0055] In the winding 34A of modified example 1, the multiple layers of the winding 34A have a notch 41 at the end facing the tooth 33, but the notch 41 may also be provided at the end opposite the end facing the tooth 33, and the position at which the notch 41 is provided can be changed as appropriate.

[0056] Furthermore, in the winding 34A of variant example 1, a notch 41 is provided in the coil end portion E1, but the notch 41 may also be provided in the coil end portion E2, or the notch 41 may also be provided in both the coil end portions E1 and E2.

[0057] (3.2) Modification 2 The winding 34B provided in the motor 1 according to Modification 2 of the above embodiment will be described with reference to Fig. 10. Note that, since the motor 1 has the same configuration as the motor 1 of the above embodiment except for the winding 34B, the same reference numerals will be used for the common configuration and a description thereof will be omitted.

[0058] The motor 1 of variant 2 differs from the above embodiment in that a notch 42 is provided up to the middle of the thickness direction in the layer (first layer L1) closest to the rotor 2 among the multiple layers of the winding 34B.

[0059] The cutout 42 is provided only in the first layer L1 of the winding 34B, extending to the middle of the first layer L1 in the thickness direction. Because the cutout 42 does not penetrate the first layer L1 of the winding 34B, the cross-sectional area of ​​the first layer L1 can be made larger than in the case where the cutout 41 penetrates the first layer L1, as in the above embodiment. Therefore, in the motor 1 of Modification 2, the resistance of the winding 34B is reduced, and by providing the cutout 42 to the middle of the first layer L1 in the thickness direction, leakage magnetic flux linking the winding 34B can be reduced, thereby reducing eddy current loss.

[0060] In the winding 34B of the second modified example, the multiple layers of the winding 34B have a notch 42 at the end facing the tooth 33, but the notch 42 may also be provided at the end opposite the end facing the tooth 33, and the position at which the notch 42 is provided can be changed as appropriate.

[0061] In addition, in the winding 34B of variant example 2, a notch 42 is provided in the coil end portion E1, but the notch 42 may also be provided in the coil end portion E2, or the notch 42 may be provided in both the coil end portions E1 and E2.

[0062] (3.3) Modification 3 A winding 34C provided in a motor 1 according to a modification 3 of the above embodiment will be described with reference to Fig. 11. Note that, other than the winding 34C, the motor 1 has the same configuration as the motor 1 of the above embodiment, and therefore the same reference numerals will be used to designate the common configuration, and a description thereof will be omitted.

[0063] In the above embodiment, the notch 41 is formed by providing a rectangular recess at the end of the first layer L1 of the winding 34, but the shape of the notch can be changed as appropriate.

[0064] In winding 34C of modification 3, one or more layers have notches 43 at the ends facing teeth 33. Furthermore, in winding 34C, the shape of notches 43 when viewed from the radial direction of rotor yoke 22 is formed so that the width of notches 43 in the winding direction of wire 40 increases as it approaches teeth 33. The ends of notches 43 are inclined obliquely with respect to the end face of wire 40, which has the advantage of being easier to process than when the ends of notches 43 intersect the end face of wire 40 at right angles.

[0065] It should be noted that FIG. 11 shows an example of the shape of the notch 43, and the shape of the notch 43 can be changed as appropriate.

[0066] Furthermore, in the winding 34C of variant example 3, a notch 43 is provided in the coil end portion E1, but the notch 43 may also be provided in the coil end portion E2, or the notch 43 may also be provided in both the coil end portions E1 and E2.

[0067] (3.4) Modification 4 A winding 34D provided in a motor 1 according to Modification 4 of the above embodiment will be described with reference to Fig. 12. Note that, since the motor 1 has the same configuration as the motor 1 of the above embodiment except for the winding 34D, the same reference numerals will be used for the common configuration and a description thereof will be omitted.

[0068] In the above embodiment, the notch 41 is formed by providing a recess at the end of the first layer L1 of the winding 34, but the shape of the notch can be changed as appropriate.

[0069] In the winding 34D of Modification 4, a notch 44, which is a through-hole that penetrates the first layer L1, is provided in the center of the first layer L1 in the width direction (direction perpendicular to the winding direction) of the wire 40. That is, in Modification 4, the notch 44 is a hole with a closed periphery. Even when the notch 44 is a hole with a closed periphery, leakage flux that links with the winding 34D is reduced compared to when the notch 44 is not provided, and eddy current loss can be reduced.

[0070] Although the notch 44 penetrates only the first layer L1 of the winding 34D, the notch 44 may be formed to penetrate multiple layers of the winding 34D.

[0071] Although the notch 44 is provided in the coil end portion E1, it may also be provided in the coil end portion E2, or may be provided in both the coil end portions E1 and E2. The notch 44 may also be a hole that penetrates multiple layers including the first layer L1.

[0072] (3.5) Modification 5 A winding 34E provided in a motor 1 according to Modification 5 of the above embodiment will be described with reference to Figures 13 and 14. Note that, since the motor 1 has the same configuration as the motor 1 of the above embodiment except for the winding 34E, the same reference numerals will be used for the common configuration and a description thereof will be omitted.

[0073] In the above embodiment, the coil end E1 of the winding 34 is provided with a notch 41, but in Modification 5, the first layer L1 of the winding 34E has notches 45 (see FIG. 13 ) in each of the intermediate regions F1 and F2 between the coil end E1 and the coil end E2. That is, the first layer L1 of the winding 34E has notches 45 in each of two intermediate regions F1 and F2 that face each other in the circumferential direction of the rotor yoke 22. More specifically, the first layer L1 of the winding 34E has notches 45 in each of the ends of the intermediate regions F1 and F2 that face the teeth 33. By providing notches 45 in each of the intermediate regions F1 and F2, leakage flux linking the winding 34E can be reduced, thereby reducing eddy current loss.

[0074] As shown in FIG. 14, the first layer L1 of the winding 34E may have notches 46 at the ends of the intermediate portions F1 and F2, opposite the ends facing the teeth 33.

[0075] Furthermore, in the intermediate portions F1, F2 of the winding 34E, it is not essential that the notches 45, 46 are provided only in the first layer L1, but the notches 45, 46 may be provided in multiple layers. Furthermore, it is not essential that the notches 45, 46 are provided in both the intermediate portions F1, F2 of the winding 34E, but the notches 45, 46 may be provided in only one of the intermediate portions F1, F2.

[0076] (3.6) Modification 6 A winding 34F provided in a motor 1 according to Modification 6 of the above embodiment will be described with reference to Fig. 15. Note that, other than the winding 34F, the motor 1 has the same configuration as the motor 1 of the above embodiment, and therefore the same reference numerals will be used to designate the common configuration, and a description thereof will be omitted.

[0077] In the above embodiment, the notch 41 is formed at one location in the coil end portion E1 of the first layer L1 of the winding 34, but the location and number of the notches can be changed as appropriate.

[0078] In the sixth modification, as shown in FIG. 15, three notches 47 are provided at a plurality of positions (for example, three positions) in the coil end portion E1 of the first layer L1 of the winding 34F.

[0079] In this way, one or more of the multiple layers of the winding 34F may have notches 47 at multiple positions in the winding direction of the wire 40, thereby reducing the leakage magnetic flux interlinking with the winding 34F and reducing eddy current loss.

[0080] Furthermore, in the above-mentioned modified examples 1 to 5, the number and positions of the cutouts 41 to 46 can be changed as appropriate, and multiple cutouts 41 to 46 may be provided in one or more layers including at least the first layer L1.

[0081] Furthermore, in the above-mentioned variants 1 to 6, in some of the multiple windings 34A to 34F wound around the multiple teeth 33, a notch 41 may be provided in one or more layers, including the layer L1 closest to the rotor 2.

[0082] (Summary) The above-described embodiments and the like disclose the following aspects.

[0083] A motor (1) of a first aspect includes a rotor (2) and a stator (3). The rotor (2) includes a cylindrical rotor yoke (22) having a rotation axis (21) whose center of rotation is an axis (Ax1), and a plurality of magnets (23) arranged on the side of the rotor yoke (22) along the circumferential direction of the rotor yoke (22). The stator (3) includes a cylindrical stator yoke (32), a plurality of teeth (33), and a plurality of windings (34, 34A-34F). The stator yoke (32) is arranged concentrically with the rotor (2). The plurality of teeth (33) protrude from the inner peripheral surface of the stator yoke (32) toward the rotation axis (21) from a plurality of positions along the circumferential direction of the rotor yoke (22). The plurality of windings (34, 34A-34F) are wound around the plurality of teeth (33), respectively. Each of the plurality of windings (34, 34A to 34F) is formed by winding a rectangular wire (40) in multiple layers, and has a plurality of layers (L1 to L11) that overlap in the protruding direction of a corresponding one of the plurality of teeth (33). In each of the plurality of windings (34, 34A to 34F), notches (41 to 47) are provided in one or more of the layers (L1 to L11) including the layer (L1) closest to the rotor (2).

[0084] According to this aspect, the length of the gap between the magnet (23) and the windings (34, 34A to 34F) can be made longer than when the cutouts (41 to 47) are not provided, thereby reducing the leakage flux interlinking with the windings (34, 34A to 34F) and further reducing eddy current loss.

[0085] In the motor (1) of the second aspect, in the first aspect, one or more layers (L1 to L11) are provided with notches (41 to 43, 45, 47) at the ends facing the teeth (33).

[0086] According to this aspect, by providing the notches (41 to 43, 45, 47) in areas where leakage magnetic flux is likely to concentrate, the leakage magnetic flux linking the windings (34, 34A to 34C, 34E, 34F) can be reduced, and eddy current loss can be further reduced.

[0087] In the motor (1) of the third aspect, in the second aspect, the shape of the notch (43) when viewed from the radial direction of the rotor yoke (22) is formed so that the width of the notch (43) in the winding direction of the wire (40) increases as it approaches the teeth (33).

[0088] This embodiment has the advantage that the cutout portion (43) can be easily processed.

[0089] In the motor (1) of the fourth aspect, in any of the first to third aspects, the notches (41 to 47) are provided only in the layer (L1) of the multiple layers (L1 to L11) that is closest to the rotor (2).

[0090] According to this aspect, it is possible to reduce the leakage flux interlinking with the windings (34, 34A to 34F) while lowering the resistance of the windings (34, 34B to 34F), thereby further reducing eddy current loss.

[0091] In the motor (1) of the fifth aspect, in the fourth aspect, a notch (42) is provided up to the middle of the thickness direction in the layer (L1) closest to the rotor (2) among the multiple layers (L1 to L11).

[0092] According to this aspect, it is possible to reduce the leakage flux interlinking with the winding (34B) while reducing the resistance of the winding (34B), and it is possible to further reduce eddy current loss.

[0093] In the motor (1) of the sixth aspect, in any one of the first to third aspects, the notch (44) is a hole with a closed periphery.

[0094] According to this aspect, it is possible to reduce leakage flux interlinking with the winding (34D), and it is possible to further reduce eddy current loss.

[0095] In the motor (1) of the seventh aspect, in any of the first to sixth aspects, one or more layers (L1 to L11) are provided with notches (47) at multiple positions in the winding direction of the wire (40).

[0096] According to this aspect, it is possible to reduce leakage flux interlinking with the winding (34F), and it is possible to further reduce eddy current loss.

[0097] In the motor (1) of the eighth aspect, in any of the first to seventh aspects, in one or more layers (L1 to L11), cutout portions (41 to 44, 47) are provided in coil end portions (E1, E2) located outside the rotor yoke (22) when viewed from the radial direction of the rotor yoke (22).

[0098] According to this aspect, by providing notches (41 to 44, 47) in the coil end portions (E1, E2) where leakage magnetic flux tends to concentrate, the leakage magnetic flux interlinking with the windings (34, 34A to 34D, 34F) can be reduced, and eddy current loss can be further reduced.

[0099] The configurations according to the second to eighth aspects are not essential for the motor (1) and may be omitted as appropriate.

[0100] REFERENCE SIGNS LIST 1 motor 2 rotor 3 stator 21 rotating shaft 22 rotor yoke 23 magnet 32 ​​stator yoke 33 teeth 34, 34A to 34F winding 40 wire rod 41 to 47 notch Ax1 shaft center E1, E2 coil end L1 to L11 layer

Claims

1. A rotor, a stator; The rotor is a cylindrical rotor yoke having a rotation axis whose center is the axis of rotation; a plurality of magnets arranged on a side surface of the rotor yoke along a circumferential direction of the rotor yoke, The stator includes: a cylindrical stator yoke arranged concentrically with the rotor; a plurality of teeth projecting from an inner peripheral surface of the stator yoke at a plurality of positions in a circumferential direction of the rotor yoke toward the rotation shaft; a plurality of windings wound around the plurality of teeth, Each of the plurality of windings is formed by winding a flat wire material in multiple layers, and has a plurality of layers that overlap in a protruding direction of a corresponding one of the plurality of teeth, In each of the plurality of windings, a notch is provided in one or more layers of the plurality of layers, including the layer closest to the rotor. Motor.

2. The one or more layers are provided with the notches at ends facing the teeth. The motor according to claim 1 .

3. The shape of the notch when viewed from the radial direction of the rotor yoke is formed so that the width of the notch in the winding direction of the wire increases as it approaches the tooth. The motor according to claim 2 .

4. the notch is provided only in the layer closest to the rotor among the plurality of layers; The motor according to any one of claims 1 to 3.

5. the notch is provided up to a middle portion in a thickness direction of the layer closest to the rotor among the plurality of layers; 5. The motor according to claim 4.

6. The notch is a hole whose periphery is closed. The motor according to any one of claims 1 to 3.

7. the one or more layers are provided with the notches at a plurality of positions in the winding direction of the wire rod; The motor according to any one of claims 1 to 3.

8. In the one or more layers, the notch is provided in a coil end portion located outside the rotor yoke as viewed in the radial direction of the rotor yoke. The motor according to any one of claims 1 to 3.