Motor

Abstract

To reduce a length in an axis direction.SOLUTION: A motor includes a stator and a substrate. The stator includes a plurality of magnetic bodies arranged in the circumferential direction, and coils wound around the respective magnetic bodies. The substrate faces the stator in the rotational axis direction. The coils each include a first layer and a second layer that is deposited on the first layer. When the thickness of each magnetic body in the rotational axis direction and the width of each magnetic body in the radial direction are defined as L and D, respectively, 1≤D / L is established. The second layer is the furthest layer from the magnetic body. In the radial direction, a conductive wire of the first layer and a conductive wire of the second layer, which form an inner edge of the coil, are in contact with each other. In the radial direction, a conductive wire of the first layer and a conductive wire of the second layer, which form an outer edge of the coil, are in contact with each other.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a motor. [Background technology]

[0002] A so-called flat motor is known in which the radial length of a stator core is greater than the axial length of the stator core, and in which a connecting member such as a circuit board is disposed in close proximity to the stator of the motor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-033873 A [Patent Document 2] JP 2000-166193 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a flat motor, it is required to reduce the axial length of the motor, but in order to suppress magnetic flux saturation and increase torque, it is preferable to ensure the axial height of the stator core (stack length).

[0005] One aspect of the present invention is to provide a motor that can reduce its axial length. [Means for solving the problem]

[0006] In one embodiment, the motor comprises a stator; A rotor; a sensor; Substrate and , a housing, The stator includes a plurality of magnetic bodies arranged in a circumferential direction, coils wound around each of the magnetic bodies, and Insulators and Equipped with. The rotor has a thickness equal to or greater than a thickness of the magnetic bodies in the axial direction of the rotation axis, and the sensor is disposed opposite the rotor in the axial direction of the rotation axis. The substrate faces the stator in the direction of the rotation axis. The housing includes the sensor.The coil includes a first layer and a second layer stacked on top of the first layer. The rotor is disposed inside the stator. The housing accommodates the rotor, the stator, and the substrate. The above in the direction of the rotation axis Multiple The thickness of the magnetic body is L, and the Multiple The width of the magnetic body is D, and the ratio D / L is 1≦D / L. In the rotation axis direction and the circumferential direction, The above Multiple The furthest point from the magnetic material The outermost part of the coil The conductor wires of the first layer and the conductor wires of the second layer, which form the inner edge of the coil in the radial direction, are in contact with each other, and the conductor wires of the first layer and the conductor wires of the second layer, which form the outer edge of the coil in the radial direction, are in contact with each other. The sensor is located on the rotor side of the substrate in the axial direction. The thickness of the magnetic bodies in the axial direction is greater than a sum of a thickness of the coil in the axial direction and a thickness of the insulator in the axial direction.

[0007] According to one aspect, the length in the axial direction can be reduced. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view illustrating an example of a motor according to an embodiment. [Diagram 2] FIG. 2 is an exploded perspective view illustrating an example of a motor according to an embodiment. [Diagram 3] FIG. 3 is a cross-sectional perspective view illustrating an example of a motor according to an embodiment. [Figure 4] FIG. 4 is a side cross-sectional view showing an example of a motor according to an embodiment. [Diagram 5] FIG. 5 is an exploded perspective view illustrating an example of a stator core in the embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing an example of a stator core around which a coil is wound in the embodiment. [Figure 7] FIG. 7 is a side cross-sectional view showing an example of a stator core around which a coil is wound in the embodiment. [Figure 8] FIG. 8 is a cross-sectional view illustrating an example of a stator in the embodiment. [Figure 9] FIG. 9 is a perspective view illustrating an example of a stator in the embodiment. [Figure 10]FIG. 10 is an enlarged perspective view showing an example of a connection portion in the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the motor disclosed in the present application will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments shown below. Furthermore, the dimensional relationships of the elements in the drawings, the ratios of the elements, etc. may differ from the reality. The drawings may also include parts with different dimensional relationships and ratios. For example, in FIG. 2 and other figures shown below, the shape of the wall portion 122 of the insulator 12, which will be described later, differs from the shape shown in FIG. 1 and other figures. Furthermore, the contents described in one embodiment or modified example are, in principle, similarly applicable to other embodiments or modified examples.

[0010] In the following description, for convenience, the illustrated axial direction is the direction of the rotation axis of the motor in this embodiment. One of the axial directions (upward) is the first direction, and the other (downward) is the second direction. The illustrated radial direction is the radial direction perpendicular to the direction of the rotation axis of the motor in this embodiment. Among the radial directions, the direction away from the rotation axis Z described later is the radially outward, and the direction toward the rotation axis Z is the radially inward. The illustrated circumferential direction is the direction that coincides with the rotation direction of the motor in this embodiment. In each drawing, to make the description easier to understand, coordinate axes including at least one of the axial direction, radial direction, and circumferential direction may be illustrated. In addition, in the coordinate axes, the direction toward the radially outward direction may be the positive direction.

[0011] (Embodiment) First, a motor according to an embodiment will be described with reference to Figs. 1 to 4. Fig. 1 is a perspective view showing an example of a motor according to an embodiment. Fig. 2 is an exploded perspective view showing an example of a motor according to an embodiment. Fig. 3 is a cross-sectional perspective view showing an example of a motor according to an embodiment. Fig. 4 is a side cross-sectional view showing an example of a motor according to an embodiment. Figs. 3 and 4 show cross sections taken along line AA in Fig. 1.

[0012] 1 to 4, a motor 1 in this embodiment includes a substrate 2, a stator 3, a rotor 80, and a housing 90. In the following, illustrations of parts other than the lid of the housing 90 may be omitted. The motor 1 in this embodiment is, for example, an inner rotor type brushless motor.

[0013] The stator 3 shown in FIG. 1 is disposed so as to surround the rotor 80. The motor 1 in this embodiment employs a so-called split core. The stator 3 in this embodiment includes a plurality of split cores 10, which will be described later. The stator 3 is formed by arranging the plurality of split cores 10 in an annular shape along the circumferential direction, and joining adjacent split cores 10 together. The plurality of split cores 10 are disposed, for example, in an annular shape along the circumferential direction. Each split core 10 is integrally molded, for example, by insert molding.

[0014] As shown in Fig. 4, the stator 3 includes a stator core 11, an insulator 12, and a coil 30. The stator core 11 is an example of a magnetic body. The coil 30 is formed by winding the conductor 14 around the stator 3 via the insulator 12. As shown in Fig. 2, a first end 141 and a second end 142 of the conductor 14 are drawn out from the coil 30 in the same direction (first direction) as lead wires. The stator core 11, the insulator 12, and the coil 30 will be described in detail later.

[0015] As shown in FIG. 2, the substrate 2 formed in an annular shape is disposed on the first axial direction side of the stator 3 so as to face the stator 3 in the axial direction. The substrate 2 is formed of an insulating resin material such as epoxy. The substrate 2 has two surfaces 2a and 2b. Electronic components (not shown) are disposed on the substrate 2. The electronic components include, for example, a capacitor, a resistor, an inverter, and an IC. The substrate 2 is disposed, for example, as shown in FIG. 4, so that the surface 2b faces the stator 3 in the axial direction, and is supported by the stator 3 directly or via another member. The substrate 2 may be disposed, supported by the housing 90.

[0016] As shown in Fig. 2, the substrate 2 is recessed radially inward from the outer circumferential end and has a plurality of recesses 21, 22 adjacent to each other in the circumferential direction. Hereinafter, the recess 21 may be referred to as the first recess 21 or the substrate-side first recess 21, and the recess 22 may be referred to as the second recess 22 or the substrate-side second recess 22. In this embodiment, a land 29 is formed on the surface 2a of the substrate 2. In addition, a substrate protrusion 23 is formed as a protrusion in the circumferential direction between the substrate-side first recess 21 and the substrate-side second recess 22. The substrate protrusion 23 is formed to protrude radially outward from the outer periphery of the substrate 2.

[0017] The land 29 is formed of a conductive material and is a connection portion connected to the conductor 14. As will be described later, a first end 141 and a second end 142 of the conductor 14 drawn out from the coil 30 are physically and electrically connected to the land 29 by solder 19, which is an alloy shown in Fig. 1. Note that the land 29 is not visible in Figs. 3 and 4 because it is covered with the solder 19.

[0018] The rotor 80 is disposed radially inside the stator 3. As shown in Fig. 3, the rotor 80 includes a rotor magnet 81 and a rotor core 82. The rotor magnet 81 is, for example, a tubular or cylindrical magnet fixed to the outer circumferential surface of the rotor core 82. The rotor magnet 81 is, for example, formed of a rare earth magnet such as a neodymium magnet. The rotor core 82 is, for example, fixed to the outer circumferential surface of a shaft (not shown).

[0019] 3 and 4, in this embodiment, the height (size in the axial direction) L2 of the rotor magnet 81 is formed to be larger than the height (size in the axial direction) L of the stator core 11.

[0020] The housing 90 accommodates the substrate 2, the stator 3, and the rotor 80. The housing 90 includes a lid portion, and an outer periphery and a bottom portion (not shown). As shown in FIG. 2, the lid portion of the housing 90 covers part or all of the substrate 2 and the stator 3 when viewed from above.

[0021] The housing 90 further includes a sensor 91 and a sensor holder 92. The sensor 91 detects at least one of the rotation speed and the rotation angle of the rotor 80 by detecting the magnetic flux of the rotor magnet 81. As shown in FIG. 4, the sensor holder 92 extends from a surface of the housing 90 on the second direction side in the axial direction toward the second direction side. The sensor 91 is disposed on the surface of the sensor holder 92 on the second direction side (the rotor 80 side). As shown in FIGS. 2 to 4, the sensor 91 is disposed at a predetermined distance away from the rotor magnet 81 so as to face the rotor magnet 81 in the axial direction. In addition, the position P1 of the sensor 91 in the axial direction is closer to the rotor 80 side than the position P2 of the substrate 2 in the axial direction, that is, on the second direction side in the axial direction.

[0022] Next, the configuration of each split core 10 will be described with reference to Figs. 5 to 8. Fig. 5 is an exploded perspective view showing an example of a stator core in an embodiment. Fig. 6 is a cross-sectional view showing an example of a stator core around which a coil is wound in an embodiment. Fig. 7 is a side cross-sectional view showing an example of a stator core around which a coil is wound in an embodiment. Fig. 8 is a cross-sectional view showing an example of a stator in an embodiment. As shown in Figs. 5 to 8, each split core 10 includes a stator core 11, an insulator 12, and a coil 30. Note that the coil 30 is not shown in Fig. 5. Also, the conductor wire 14 drawn out as a lead wire from the coil 30 is not shown in Fig. 7.

[0023] The stator core 11 is a magnetic body having a laminated structure in which, for example, a plurality of electromagnetic steel sheets are laminated in the axial direction. The plurality of stator cores 11 are arranged in an annular shape along the circumferential direction. The stator core 11 has teeth 11a having magnetic pole portions as ends facing the rotor 80, and a yoke 11b. The teeth 11a extend from the inner surface of the yoke 11b toward the radially inner side (toward the rotor 80). As shown in FIG. 8, the yoke 11b is connected to the adjacent yoke 11b in the circumferential direction in a state in which the plurality of split cores 10 are arranged in an annular shape along the circumferential direction. The yoke 11b is an example of an outer periphery.

[0024] The stator core 11 of the motor 1, which is a so-called flat motor, is formed so that its length (width) in the radial direction is greater than its height (thickness) in the axial direction. In this embodiment, as shown in Fig. 7, the ratio (D / L) of the width D of the stator core 11 in the radial direction to the thickness L of the stator core 11 in the axial direction is greater than 1. Furthermore, it is preferable that D / L is greater than 4.5. The thickness L of the stator core 11 in this embodiment is, for example, 20 mm or less.

[0025] The insulator 12 is formed of an insulating material such as resin, and is interposed between the stator core 11 and the coil 30 to electrically insulate the coil 30 from the stator core 11. As shown in Fig. 5, the insulator 12 has an accommodating portion 121 that accommodates the stator core 11 therein, a wall portion 122 formed at a radially outer end of the accommodating portion 121, a top surface 123 formed at both axially outer ends of the accommodating portion 121, and side surfaces 125 formed at both circumferential ends of the accommodating portion 121. The insulator 12 is formed so as to be separable into two, and in the divided state, the stator core 11 can be accommodated inside in the axial direction.

[0026] The wall portion 122 of the insulator 12 is located on the outer periphery of the substrate 2 in an assembled state in which the substrate 2 is assembled to the stator 3. The wall portion 122 is formed in a substantially rectangular shape when viewed in the radial direction, and is formed to protrude from the yoke 11b in the axial direction. In this embodiment, as shown in Fig. 5, the wall portion 122 is formed with a recessed portion 122A recessed in the axial direction and an inclined surface 122B inclined to form a predetermined angle with respect to the axial direction.

[0027] Next, the operation of winding the conductor 14 around the insulator 12 in this embodiment to form the coil 30 will be described. The coil 30 is wound clockwise or counterclockwise around the teeth 11a of the stator core 11 through the housing portion 121 of the insulator 12 so as to surround the top surface 123 and the side surface 125 of the insulator 12. The coil 30 in this embodiment is, for example, a so-called concentrated winding coil wound around one stator core 11. The conductor 14 in this embodiment is, for example, a round copper wire.

[0028] As shown in Figs. 6 to 8, the coil 30 includes a first layer 31 and a second layer 32 stacked on the first layer 31 in the axial direction. When the conductor 14 is wound around the insulator 12, the first layer 31 of the coil 30 is wound on the top surface 123. At that time, the multiple conductors 1n forming the first layer 31 of the coil 30 are wound so as to be in contact with each other in the radial direction, as shown in Figs. 7 and 8, for example. In this embodiment, the conductor 1n is wound radially inward, for example, starting from the first layer conductor 1o constituting the outer edge oE of the coil 30, toward the first layer conductor 1i constituting the inner edge iE of the coil 30.

[0029] Next, a conductor is wound axially outward from the first layer conductor 1i to form a second layer of the coil 30. In this case, as shown in Fig. 7, the first layer conductor 1i and the second layer conductor 2i constituting the inner edge iE of the coil 30 are in contact with each other.

[0030] The conductor wire 2n forming the second layer of the coil 30 is wound radially outward from the conductor wire 2i toward the second layer conductor wire 2o forming the outer edge oE of the coil 30. In this case, as shown in Fig. 7, the first layer conductor wire 1o and the second layer conductor wire 2o constituting the outer edge oE of the coil 30 are in contact with each other.

[0031] In this embodiment, as shown in Fig. 6 and Fig. 7, for example, the radially inner end I2 of the conductor 2i is located closer to the outer edge oE than the radially inner end I1 of the conductor 1i, i.e., closer to the outer side in the radial direction. Similarly, the radially inner end O2 of the conductor 2o is located closer to the inner edge iE than the radially inner end O1 of the conductor 1o, i.e., closer to the inner side in the radial direction. In this case, the number of turns of the conductor 2n constituting the second layer 32 is smaller than, for example, the number of turns of the conductor 1n constituting the first layer 31. More specifically, the number of turns T2 of the conductor 2n is the same as the number of turns T1 of the conductor 1n or is smaller by 1 than T1.

[0032] In addition, in this embodiment, the radial length T from the inner edge conductor 2i to the outer edge conductor 2o of the conductor 2n constituting the second layer is smaller than the radial length S from the inner circumference side to the outer circumference side of the substrate 2, as shown in Figure 7.

[0033] In addition, the entire coil 30 in this embodiment is located inside the extension line of the yoke 11b of the stator core 11 in the circumferential direction in top view. For example, as shown in FIG. 6, the second layer 32 in the outermost layer of the coil 30 is located closer to the stator core 11 in the circumferential direction than the extension lines Xa and Xb of the end faces Ea and Eb of the yoke 11b of the stator core 11 in the circumferential direction. In this configuration, as shown in FIG. 8, gaps G1 and G2 are formed between the coils 30 of the split core 10 adjacent in the circumferential direction. In this embodiment, the outer edge oE of the coil 30 is located inside the inclined portion B1 of the insulator 12 in the radial direction as shown in FIG. 6.

[0034] In this embodiment, the axial length (thickness) L of the stator core 11 is greater than the sum of the axial lengths (thicknesses of the coil end portions) Ta and Tb of the coils 30, as shown in Fig. 4. Note that in this embodiment, the thickness L of the stator core 11 is greater than the sum of the axial thicknesses Tx and Ty of the insulators 12 in addition to Ta and Tb.

[0035] In this case, the second layer 32 of the coil 30 is the layer that is the furthest in the axial and circumferential directions from the stator core 11. By reducing the number of coil turns, the height of the stator is reduced.

[0036] Next, the work of routing the first end 141 and the second end 142 of the conductor 14, which is a lead wire drawn from the coil 30 in this embodiment, and assembling it into the first recess 21 on the board side and the second recess 22 on the board side will be described with reference to Figs. 9 and 10. Fig. 9 is a perspective view showing an example of a stator in the embodiment. Fig. 10 is an enlarged perspective view showing an example of a connection part in the embodiment. In this embodiment, the first end 141 of the coil 30 is drawn from the conductor 2o on the outer edge side of the second layer 32 of the coil 30 shown in Fig. 7. The second end 142 of the coil 30 is drawn from the conductor 1o on the outer edge side of the first layer 31 of the coil 30. In this embodiment, both the first end 141 and the second end 142 are drawn from the outer periphery side of the coil 30 in the radial direction, as shown in Fig. 9.

[0037] The first end 141 and the second end 142 of the conducting wire 14 drawn out in the first direction are connected to the land 29 of the substrate 2 as shown in Fig. 10. At that time, the first end 141 and the second end 142 are tilted toward the inclined surface 122B shown in Fig. 5, that is, outward in the radial direction, and escape along the inclined surface 122B toward the recessed portion 122A.

[0038] 10, a first end 141, which is one end of the conductor 14 drawn from the coil 30, is passed through the board-side first recess 21. As shown in FIG. 10, a second end 142, which is the other end of the conductor 14 drawn from the coil 30, is passed through the board-side second recess 22.

[0039] In an assembled state in which the board 2 is assembled to the stator 3, the first end 141 of the conductive wire 14 is located inside the board-side first recess 21, and the other end 142 is located inside the board-side second recess 22. The first end 141 and the second end 142 are arranged in a direction facing each other in the circumferential direction. The first end 141 and the second end 142 sandwich the board protrusion 23 between the board-side first recess 21 and the board-side second recess 22 in the circumferential direction. As shown in FIG. 10, the first end 141 and the second end 142 are joined to the land 29 of the board 2 by, for example, solder 19 in a state in which the board protrusion 23 between the board-side first recess 21 and the board-side second recess 22 is sandwiched in the circumferential direction.

[0040] In this embodiment, the first end 141 of the conducting wire 14 and another coil 30 wound around another split core 10 are electrically connected via the substrate 2. In this case, the first end 141 and the lead wires drawn out from the other coils 30 do not intersect with each other. This eliminates the need to secure a space for the lead wires to intersect, and therefore the axial length of the motor 1 can be reduced.

[0041] The first layer 31 and the second layer 32 of the coil 30 are wound so that the cross-sectional shape of the coil 30 shown in Fig. 6 is within a substantially rectangular frame. When the number of turns T2 of the conductor 2n of the second layer 32 is smaller than the number of turns T1 of the conductor 1n of the first layer 31, the cross-sectional shape of the coil 30 is contained within a substantially trapezoidal frame, and the length in the radial direction of the second layer 32 is slightly smaller than the length of the first layer 31. In either case, the outer shape of the coil 30 formed by the second layer 32 (axial outer side) of the coil 30 in the axial direction does not include a portion protruding outside the substantially rectangular or trapezoidal frame.

[0042] In this embodiment, the second layer 32 of the coil 30 is wound starting from a part of the inner edge conductor 2i of the coil 30 on the circumferential side after the first layer 31 is wound from the outer edge conductor 1o to the inner edge conductor 1i. That is, the winding start of the second layer 32 is formed at the circumferential end of the inner edge iE of the coil 30. Even in this case, a gap G2 is secured between the inner edges of two coils 30 adjacent in the circumferential direction, so that interference with other coils 30 adjacent in the circumferential direction can be suppressed. In addition, compared to the case where the winding start of the second layer 32 is at the end of the coil 30 on the axial direction side, it is possible to suppress collapse of the coil 30 and to suppress the axial length of the motor.

[0043] As described above, the motor 1 in this embodiment includes the stator 3 and the substrate 2. The stator 3 includes a plurality of magnetic bodies 11 arranged in a circumferential direction, and the coils 30 wound around each of the magnetic bodies 11. The substrate 2 faces the stator 3 in the rotation axis direction. The coil 30 includes a first layer 31 and a second layer 32 stacked on the first layer 31. The thickness of the magnetic body 11 in the rotation axis direction is L, and the width of the magnetic body 11 in the radial direction is D, and 1≦D / L holds. The second layer 32 is the layer farthest from the magnetic body 11. In the radial direction, the conductor 1i of the first layer 31 and the conductor 2i of the second layer 32, which constitute the inner edge iE of the coil 30, are in contact with each other, and in the radial direction, the conductor 1o of the first layer 31 and the conductor 2o of the second layer 32, which constitute the outer edge oE of the coil 30, are in contact with each other. With this configuration, the length of the motor 1 in the axial direction can be reduced.

[0044] In the motor 1, the conductor 2i of the second layer 32 constituting the inner edge iE is located on the outer edge oE side in the radial direction relative to the conductor 1i of the first layer 31 constituting the inner edge iE, and the conductor 2o of the second layer 32 constituting the outer edge oE is located on the inner edge iE side in the radial direction relative to the conductor 1o of the first layer 31 constituting the outer edge oE. In the motor 1, the conductors 1n adjacent to each other in the radial direction forming the first layer 31 are in contact with each other in the radial direction, and the conductors 2n adjacent to each other in the radial direction forming the second layer 32 are in contact with each other in the radial direction. The lead wire 14 drawn from the coil 30 is drawn out from the outer edge oE of the coil 30. In the coil 30 of the motor 1, the start of winding of the second layer 32 is formed at the end of the conductor 2i of the second layer 32 constituting the inner edge iE of the coil 30 in the circumferential direction of the coil 30. According to this configuration, it is possible to prevent the coil 30 from collapsing while ensuring the space factor of the coil 30.

[0045] In the motor 1, the entire coil 30 is on the magnetic body 11 side in the circumferential direction with respect to the extension lines X1, X2 of the end faces Ea, Eb of the outer circumferential portion 11b of the magnetic body 11. In this case, a gap is formed in the circumferential direction between the coils 30 wound around each of the two magnetic bodies 11 that are adjacent in the circumferential direction among the multiple magnetic bodies 11. In addition, in the radial direction, the ratio of the length T from the inner edge side conductor 2i of the second layer 32 to the outer edge side conductor 2o to the length S from the inner circumferential portion to the outer circumferential portion of the substrate 2 is in the range of 50% to 90%. According to this configuration, by providing the gaps G1 and G2 as shown in FIG. 8, the two coils 30 adjacent in the circumferential direction interfere with each other, and the decrease in the roundness of the stator 3 can be suppressed. In addition, by ensuring the gaps G1 and G2, the winding heat dissipation of the coil 30 by air cooling is improved, and when heat dissipation is enhanced by resin such as mold or varnish, the resin can be selected without being restricted by viscosity.

[0046] The motor 1 also includes a rotor 80 having a thickness L2 equal to or greater than the thickness L of the magnetic body 11 in the direction of rotation axis, and a sensor 91 disposed opposite the rotor 80 in the direction of rotation axis. In the direction of rotation axis, the sensor located at height P2 is on the rotor 80 side, i.e., on the negative side in the direction of rotation axis, with respect to the substrate located at height P1. The lead wire 14 is drawn through recesses 21 and 22 formed in the outer periphery of the substrate 2. The lead wire 14 and the lead wire 14 drawn from the other coils 30 are electrically connected via the substrate 2. According to this configuration, the recesses 21 and 22 formed in the substrate 2 ensure a connection area between the lead wire 14 and the substrate 2, and the distance between the substrate 2 and the stator 3 can be reduced, so that the length of the motor 1 in the direction of the axis can be reduced. In addition, the sensor 91 can be brought closer to the rotor magnet 81, so that the detection accuracy of the magnetic flux in the sensor 91 can be improved. Furthermore, by making the thickness L2 of the rotor 80 larger than the thickness L of the stator core 11, demagnetization due to interference between the magnetic flux of the stator 3 and the magnetic flux of the rotor 80 is less likely to occur.

[0047] Furthermore, in motor 1, the thickness L in the axial direction of magnetic body 11 is greater than the sum of the thicknesses Ta, Tb in the axial direction of coil 30. With this configuration, even in motor 1, which is a flat motor, the number of stator cores (stack length) can be increased, thereby suppressing the occurrence of magnetic flux saturation and increasing torque.

[0048] Although the configuration of the present embodiment has been described above, the present embodiment is not limited to this. For example, the motor 1 is not limited to a brushless motor. In addition, the conductor 14 may be further wound inward in the axial direction from the first layer 31 of the coil 30, that is, at a position closer to the stator core 11.

[0049] 2, 9, and 10, the wall 122 of the insulator 12 may be formed with two recesses 126 and 127 and a protrusion 128 located between the two recesses. In this case, the two recesses 126 and 127 are radially opposed to the positions at which the two conductors 14 are drawn out from the coil 30. The end of the protrusion 128 is formed so as to have a lower axial height (located on the negative axial side) than the end of the wall 122 in the first direction. In the configuration shown in FIGS. 9 and 10, the first end 141 and the second end 142 may be tilted outward in the radial direction to allow them to escape to the recesses 126 and 127.

[0050] Furthermore, although the conductor 14 forming the coil 30 is composed of a single copper round wire, the present invention is not limited to this, and the conductor 14 may be composed of multiple round wires. In this case, it is sufficient that any of the multiple round wires constituting adjacent conductors 14 contact any of the multiple round wires constituting other conductors 14. Also, instead of a copper round wire, a conductor 14 of a different shape, such as a rectangular wire, may be used.

[0051] Although the present invention has been described above based on the embodiment and each modification, it goes without saying that the present invention is not limited to the embodiment and each modification, and various modifications are possible within the scope of the gist of the present invention. Such modifications that do not depart from the scope of the gist are also included in the technical scope of the present invention, and this will be clear to those skilled in the art from the description of the claims. [Explanation of symbols]

[0052] 1 motor, 2 board, 3 stator, 10 split core, 11 stator core, 11a teeth, 11b yoke, 12 insulator, 14 conducting wire, 19 solder, 2a, 2b surface, 21 first recess on board side, 22 second recess on board side, 29 land, 30 coil, 31 first layer, 32 second layer, 80 rotor, 81 rotor magnet, 82 rotor core, 90 lid (housing), 91 sensor, 92 sensor holder, 121 storage section, 122 wall, 123 top surface, 125 side surface

Claims

1. a stator including a plurality of magnetic bodies arranged in a circumferential direction, coils wound around each of the magnetic bodies, and an insulator; a rotor having a thickness equal to or greater than a thickness of the plurality of magnetic bodies in a rotation axis direction; a sensor disposed opposite the rotor in a direction of a rotation axis; a substrate facing the stator in a rotation axis direction; a housing comprising the sensor; Equipped with the coil comprises a first layer and a second layer stacked on the first layer; The rotor is disposed inside the stator, the housing accommodates the rotor, the stator, and the substrate; where L is a thickness of the plurality of magnetic bodies in the rotation axis direction and D is a width of the plurality of magnetic bodies in the radial direction, and 1≦D / L; the second layer is an outermost layer of the coil that is farthest from the plurality of magnetic bodies in the rotation axis direction and the circumferential direction, In the radial direction, the first layer conductor and the second layer conductor constituting the inner edge of the coil are in contact with each other, In the radial direction, the first layer conductor and the second layer conductor constituting the outer edge of the coil are in contact with each other, the sensor is located on the rotor side with respect to the substrate in the direction of the rotation axis; a thickness of the magnetic bodies in the rotational axis direction is greater than a sum of a thickness of the coil in the rotational axis direction and a thickness of the insulator in the rotational axis direction; Motor.

2. the second layer of conductors constituting the inner edge are located on the outer edge side in the radial direction relative to the first layer of conductors constituting the inner edge, The second layer of conductors constituting the outer edge is located on the inner edge side in the radial direction relative to the first layer of conductors constituting the outer edge.

2. The motor according to claim 1.

3. the conductors that are adjacent to each other in the radial direction and form the first layer are in contact with each other in the radial direction; the conductors forming the second layer that are adjacent to each other in the radial direction are in contact with each other in the radial direction; 2. The motor according to claim 1.

4. With respect to an extension line of an end surface of an outer periphery of the plurality of magnetic bodies, the entire second layer is located on a side of a portion of the plurality of magnetic bodies around which the coil is wound.

4. A motor according to claim 1.

5. 5. The motor according to claim 1, wherein a gap is provided between the coils wound around two circumferentially adjacent magnetic bodies among the plurality of magnetic bodies.

6. 6. The motor according to claim 1, wherein a lead wire drawn from said coil is drawn out from an outer edge of said coil.

7. The motor according to claim 6 , wherein the lead wires are led out through recesses formed in an outer periphery of the substrate.

8. The motor according to claim 6 or 7, wherein the lead wire and a lead wire drawn from another of the coils are electrically connected to each other via the substrate.

9. A motor as described in any one of claims 1 to 8, wherein in the radial direction, the ratio of the length from the inner edge to the outer edge of the second layer to the length from the inner circumference to the outer circumference of the substrate is in the range of 50% to 90%.

10. The first layer of the coil is wound starting from the outer edge of the coil and winding toward the inner edge of the coil, 10. The motor according to claim 1, wherein the start of the winding of the second layer of the coil is formed at an end, in the circumferential direction of the coil, of the second layer of conductor that constitutes an inner edge of the coil.

Images