Motor

Abstract

To simplify the configuration of a motor.SOLUTION: A motor includes a yoke having a plurality of magnetic pole portions aligned in the circumferential direction and a plurality of air core coils aligned in the circumferential direction. The plurality of magnetic pole portions is arranged inside one of the plurality of air core coils in the circumferential direction. Of the plurality of air core coils, connecting portions drawn from two adjacent air core coils are electrically connected.SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] 2. Description of the Related Art In rotating electrical machines such as motors, a distributed winding technique is known in which a coil is arranged across a plurality of magnetic pole portions. In the distributed winding technique, for example, it is known to use segment coils. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-6082 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-223028 [Patent Document 3] JP 2016-73120 A Summary of the Invention [Problem to be solved by the invention]

[0004] Segment coils require a lot of man-hours to form and weld the rectangular wire, making the motor structure complicated. In addition, the coil ends protrude in the axial direction, which hinders efforts to make the motor more compact.

[0005] One aspect of the present invention aims to simplify the configuration of a motor. [Means for solving the problem]

[0006] In one embodiment, the motor includes a stator. The stator includes a yoke having a plurality of magnetic pole portions arranged in a circumferential direction, a plurality of air-core coils arranged in a circumferential direction, and a plurality of joint portions. The plurality of magnetic pole portions are arranged inside any of the plurality of air-core coils in the circumferential direction. Two adjacent air-core coils among the plurality of air-core coils include two connection ends arranged in a circumferential direction. The two connection ends form the joint portion. The winding directions of the two adjacent air-core coils are opposite to each other.

[0007] According to one aspect, the configuration of the motor can be simplified. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a top view showing an example of a motor according to an embodiment. [Figure 2] FIG. 2 is a perspective view illustrating an example of a stator in the embodiment. [Figure 3] FIG. 3 is a perspective view illustrating an example of a first coil in the embodiment. [Figure 4] FIG. 4 is a perspective view showing an example of joining of the first coil in the embodiment. [Figure 5] FIG. 5 is a cross-sectional perspective view showing an example of a stator in the embodiment. [Figure 6] FIG. 6 is a cross-sectional perspective view showing an example of attachment of the first coil in the embodiment. [Figure 7] FIG. 7 is a cross-sectional perspective view showing an example of attachment of the second coil in the embodiment. [Figure 8] FIG. 8 is a cross-sectional perspective view showing an example of attachment of the third coil in the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of a motor disclosed herein will be described in detail below with reference to the drawings. Note that the dimensional relationships and ratios of elements in the drawings may differ from reality. The dimensional relationships and ratios may also differ between the drawings. To facilitate understanding, each drawing may illustrate a coordinate system in which the direction in which a shaft 80 (described later) extends is the axial direction and the direction in which a rotor 70 rotates is the circumferential direction.

[0010] FIG. 1 is a top view showing an example of a motor according to an embodiment. The motor 1 shown in FIG. 1 includes, for example, a stator 2, a rotor 70, and a shaft 80. The motor 1 described in each embodiment is, for example, an inner rotor type brushless motor. The motor 1 includes, for example, a rotor 70 having a plurality of magnets 71 as a component, and a rotating shaft (shaft) 80 is fixed to the rotor 70. The motor 1 is housed, for example, in a frame (not shown).

[0011] FIG. 2 is a perspective view showing an example of a stator according to an embodiment. As shown in FIGS. 1 and 2, the stator 2 according to the embodiment includes a yoke 10, a plurality of first coils 40A to 40H, a plurality of second coils 50A to 50H, and a plurality of third coils 60A to 60H. In the following description, when the plurality of first coils 40A to 40H are not distinguished from one another, they may be simply referred to as the first coil 40. The same applies to the plurality of second coils 50A to 50H and the plurality of third coils 60A to 60H. In the following description, when the first coil 40, the second coil 50, and the third coil 60 are not distinguished from one another, they may be simply referred to as the air-core coil X0.

[0012] The motor 1 in this embodiment is, for example, an 8-pole, 24-slot motor, that is, the motor 1 in this embodiment includes eight magnets 71 and 24 air-core coils X0, as shown in FIG.

[0013] The stator 2 is formed of a magnetic material such as stainless steel or a magnetic steel plate, and includes a cylindrical yoke 10 that opens in the direction of the rotation axis, and magnetic pole portions 20. In the embodiment, an insulator is formed on the surface of the yoke 10 by, for example, applying electro-deposition coating. The yoke 10 also includes 24 magnetic pole portions 20a to 20x that extend in the axial direction. Note that, hereinafter, when the multiple magnetic pole portions 20a to 20x are not to be distinguished from one another, they may be simply referred to as magnetic pole portions 20.

[0014] The magnetic pole portion 20 is formed integrally with the yoke 10 and is a protruding portion that protrudes radially inward from the inner peripheral surface of the yoke 10. In the embodiment, as shown in FIG. 2, the magnetic pole portion 20 has a shape that does not have an end portion that protrudes circumferentially on the tip side (inward in the radial direction).

[0015] In this embodiment, the 24 magnetic pole portions 20 are arranged at equal intervals in the circumferential direction. For example, as shown in Figures 1 and 2, the angle Rxa formed between adjacent magnetic pole portions 20a and 20x in the circumferential direction is approximately 15 degrees. Similarly, the angle Rwx formed between adjacent magnetic pole portions 20w and 20x in the circumferential direction is also approximately 15 degrees.

[0016] A plurality of first coils 40, a plurality of second coils 50, and a plurality of third coils 60 are arranged in the magnetic pole portion 20. The first coil 40, the second coil 50, and the third coil 60 are, for example, air-core coils that have been wound in advance. The first coil 40 is an example of a first group of air-core coils, the second coil 50 is an example of a second group of air-core coils, and the third coil 60 is an example of a third group of air-core coils.

[0017] The air core coil X0 is formed by bending a conductor wire (e.g., a rectangular wire or a round wire) made of a conductor such as copper. In the embodiment, the conductor of the conductor wire forming the air core coil X0 is covered with a coating layer made of a heat-resistant resin such as polyimide. The conductor wire forming the air core coil X0 may also be a self-bonding wire in which the coating layer is covered with a bonding layer. The bonding layer is made of a resin that can be melted by heat or a solvent to form a coating.

[0018] The air-core coil X0 has a shape that is curved in the circumferential direction. For example, the first coil 40 is formed in a curved shape in the circumferential direction so as to follow the inner peripheral surface of the yoke 10. Furthermore, the second coil 50, which is disposed radially inward (toward the rotor 70) of the first coil 40, is formed to have a larger circumferential curvature and a smaller circumferential width than the first coil 40. Similarly, the third coil 60 is formed to have an even larger circumferential curvature and an even smaller circumferential width than the second coil 50. Note that in the embodiment, the first coil 40, the second coil 50, and the third coil 60 have approximately the same axial length.

[0019] In the embodiment, for example, both the beginning and end of the air core coil X0 protrude outside the yoke 10 to serve as lead wires. That is, the conductor of the air core coil X0 is wound in a so-called alpha (α) shape. Fig. 3 is a perspective view showing an example of a first coil in the embodiment. Note that the magnetic pole portion 20 is not shown in Fig. 3.

[0020] 3, the winding start 41A and winding end 42A of the first coil 40A and the winding start 41B and winding end 42B of the first coil 40B all protrude toward the negative axial direction (the other end side of the yoke 10). The winding start 41A and 41B and the winding end 42A and 42B are examples of connection end portions.

[0021] In this embodiment, the conductor wires of two adjacent air-core coils X0 are wound in opposite directions. For example, as shown in Fig. 3, when the conductor wire of first coil 40B is wound counterclockwise (CCW) from winding start 41B to winding end 42B, the conductor wire of first coil 40A, which is circumferentially adjacent to first coil 40B, is wound clockwise (CW) from winding start 41A to winding end 42A.

[0022] In the embodiment, of the eight first coils 40, the first coils 40A, 40C, 40E, and 40G are wound clockwise, and the other first coils 40B, 40D, 40F, and 40H are wound counterclockwise, so that the N-pole coil and the S-pole coil are adjacent to each other in the circumferential direction.

[0023] 3, the first coil 40A wound counterclockwise and the first coil 40B wound clockwise start and end in the same circumferential direction. That is, between two first coils 40 adjacent to each other in the circumferential direction, for example, the winding start 41B of the first coil 40B and the winding end 42A of the first coil 40A are close to each other, and the winding end 41A of the first coil 40A and the winding start 42B of the first coil 40B are separated from each other.

[0024] Each air-core coil X0 is formed in a generally arc shape when viewed from above (axially). In this case, as shown in Fig. 3, the winding start 41A and winding end 42A of the first coil 40A and the winding start 41B and winding end 42B of the first coil 40B protrude toward the negative axial direction. Each air-core coil X0 may protrude in the circumferential or axial direction as necessary.

[0025] In addition, in the embodiment, after the air core coil X0 is placed on the magnetic pole portion 20, the winding start and winding end of adjacent air core coils X0 are electrically connected. Fig. 4 is a perspective view showing an example of joining of the first coil in the embodiment. Note that the magnetic pole portion 20 is also omitted from Fig. 4.

[0026] In the embodiment, adjacent air-core coils X0 in the circumferential direction are joined by joints 49, 59, or 69, respectively. For example, as shown in FIG. 4, first coil 40A and first coil 40B adjacent to first coil 40A are electrically connected by joint 49AB. Joint 49AB is formed, for example, by welding or ultrasonically joining winding end 42A of first coil 40A and winding start 41B of first coil 40B. Note that some joints may not be shown in FIGS. 1, 2, and 5.

[0027] 4, the first coils 40A and 40B that are adjacent to each other in the circumferential direction are spaced apart except at the joint 49AB. For example, a gap G1 is formed between the first coils 40A and 40B in the arc portion (curved portion) on the positive axial side. Note that the two air-core coils X0 that are adjacent to each other in the circumferential direction may be insulated from each other by an insulating member such as resin (not shown) except for the connection end portions. An insulating member may be present in the gap G1.

[0028] 3 and 4 also apply, with some exceptions, to the second coil 50 and the third coil 60. For example, the second coil 50A and the second coil 50B, and the third coil 60D and the third coil 60E, which are adjacent in the circumferential direction, are electrically connected by the joints 59AB and 69DE, respectively, shown in FIG.

[0029] However, in this embodiment, the second coil 50 located between the first coil 40 and the third coil 60 wound in the same circumferential direction is wound in the opposite direction. For example, like the first coil 40, the third coils 60A, 60C, 60E, and 60G are wound clockwise, while the other third coils 60B, 60D, 60F, and 60H are wound counterclockwise. On the other hand, the second coil 50A located between the first coil 40A and the third coil 60A, whose conductor wire is wound clockwise (CW), has its conductor wire wound counterclockwise (CCW). That is, the second coils 50B, 50D, 50F, and 50H are wound clockwise, while the other second coils 50A, 50C, 50E, and 50G are wound counterclockwise.

[0030] In the embodiment, the first coil 40, the second coil 50, and the third coil 60 are disposed at mutually different positions in the circumferential direction. For example, as shown in Fig. 1, the angle R12 formed between the first coil 40E and the second coil 50E in the circumferential direction is approximately 15 degrees. Similarly, the angle R23 formed between the second coil 50E and the third coil 60E, and the angle R31 formed between the first coil 40E and the third coil 60E are also approximately 15 degrees.

[0031] In this case, in the embodiment, a portion of the first coil 40 faces a portion of each of the two second coils 50 and a portion of each of the two third coils 60 in the radial direction. For example, as shown in Fig. 5, a portion of the first coil 40F faces a portion of the second coils 50E and 50F and faces a portion of the third coils 60E and 60F in the radial direction. Similarly, a portion of the second coil 50E faces a portion of the first coils 40E and 40F and faces a portion of the third coils 60D and 60E, and a portion of the third coil 60E faces a portion of the first coils 40E and 40F and faces a portion of the second coils 50E and 50F.

[0032] Fig. 5 is a cross-sectional perspective view showing an example of a stator in an embodiment. Fig. 5 shows a cross section taken along line AA in Fig. 2. As shown in Fig. 5, the second coil 50H and the second coil 50A are adjacent to each other in the circumferential direction without any other air-core coil X0 or magnetic pole portion 20 in between. Similarly, the third coil 60H and the third coil 60A are adjacent to each other in the circumferential direction without any other air-core coil X0 or magnetic pole portion 20 in between. Note that in Fig. 5, the first coil 40A and the arc portions (curved portions) of the third coil 60H and the third coil 60A are not visible.

[0033] 5, the magnetic pole portion 20a is disposed inside the second coil 50H and inside the third coil 60H in the circumferential direction. Similarly, the magnetic pole portion 20a is disposed inside the first coil 40A in the radial direction, as shown in FIG. 2. Similarly, the other magnetic pole portions 20b to 20x are disposed inside at least one of the first coil 40, the second coil 50, and the third coil 60 in the circumferential direction.

[0034] 5, eight first coils 40A to 40H arranged in a substantially circular shape in the circumferential direction constitute a first row C1. Similarly, eight second coils 50A to 50H arranged in a substantially circular shape in the circumferential direction constitute a second row C2, and eight third coils 60A to 60H arranged in a substantially circular shape in the circumferential direction constitute a third row C3.

[0035] The first row C1, the second row C2, and the third row C3 form substantially concentric circles centered on the shaft 80. That is, the first coils 40A to 40H are arranged so that they are at substantially the same radial distance from the shaft 80. The second coils 50A to 50H are arranged radially inward from the first row C1, and the third coils 60A to 60H are arranged radially inward from the first row C1 and the second row C2.

[0036] In addition, in the embodiment, the first coil 40, the second coil 50, and the third coil 60 respectively correspond to the U phase, the V phase, and the W phase of the motor 1. Note that the order of the U phase, the V phase, and the W phase is merely an example, and the order may be different from that shown in the embodiment.

[0037] In the embodiment, the air core coil X0 is arranged on the magnetic pole part 20 in the order of the first coil 40, the second coil 50, and the third coil 60. Fig. 6 is a cross-sectional perspective view showing an example of how the first coil is attached in the embodiment. Fig. 7 is a cross-sectional perspective view showing an example of how the second coil is attached in the embodiment. Fig. 8 is a cross-sectional perspective view showing an example of how the third coil is attached in the embodiment. Figs. 6 to 8 show a cross section taken along line BB in Fig. 2. Note that in the embodiment, the air core coil X0 is arranged after, for example, covering the magnetic pole part 20 with an annular insulating member (not shown).

[0038] 6, the first coil 40F is arranged so as to be in contact with the magnetic pole portions 20p and 20r of the 24 magnetic pole portions 20. In this case, the magnetic pole portion 20q, which is adjacent to the magnetic pole portion 20p and the magnetic pole portion 20r in the circumferential direction, is also arranged inside the first coil 40F. In other words, the three magnetic pole portions 20p, 20q, and 20r are arranged inside the first coil 40F. The other first coils 40A to 40E, 40G, and 40H are arranged in the same manner.

[0039] 7, the second coil 50 is disposed radially inside the first coil 40 disposed in the magnetic pole portion 20. In this case, as shown in FIG. 7, the second coil 50F is disposed at a different position in the circumferential direction from the first coils 40F and 40G adjacent to it in the radial direction.

[0040] For example, of the three magnetic pole portions 20q, 20r, and 20s arranged inside the second coil 50F in the circumferential direction, only the magnetic pole portions 20q and 20r are arranged inside the first coil 40F. The magnetic pole portion 20s is arranged inside the first coil 40G, not inside the first coil 40F. In other words, the second coil 50 is arranged at a position that straddles the two first coils 40 in the circumferential direction.

[0041] Similarly, as shown in Fig. 8, the third coil 60 is disposed radially inside the second coil 50 disposed in the magnetic pole portion 20. In this case, the third coil 60E is disposed at a different position in the circumferential direction from the second coils 50E and 50F adjacent to it in the radial direction, as shown in Fig. 8. Furthermore, the third coil 60E is disposed at a different position in the circumferential direction from any of the first coils 40.

[0042] For example, of the three magnetic pole portions 20o, 20p, and 20q arranged inside the third coil 60E in the circumferential direction, only the magnetic pole portions 20o and 20p are arranged inside the second coil 50E, and the magnetic pole portion 20r is arranged inside the second coil 50F. Also, of the three magnetic pole portions, the magnetic pole portion 20o is arranged in the first coil 40E, while the magnetic pole portions 20p and 20q are arranged in the first coil 40F. In other words, the third coil 60 is arranged in a position that straddles two first coils 40 and two second coils 50 in the circumferential direction.

[0043] Each magnetic pole portion 20 is disposed inside at least one of the air-core coils X0 in the circumferential direction. In the embodiment, each air-core coil X0 is disposed across multiple magnetic pole portions 20 in the circumferential direction. For example, the magnetic pole portion 20b is disposed inside the first coil 40A, the second coil 50A, and the third coil 60H in the circumferential direction.

[0044] As described above, eight first coils 40 are arranged in the first row C1, eight second coils 50 are arranged in the second row C2, and eight third coils 60 are arranged in the third row C3. Note that the stator 2 on which all of the air-core coils X0 are arranged may further be fitted with retainers (not shown) on both axial sides.

[0045] As described above, the motor 1 in this embodiment includes a yoke 10 having a plurality of magnetic pole portions 20 arranged in the circumferential direction, and a plurality of air core coils 40, 50, 60 arranged in the circumferential direction. The plurality of magnetic pole portions 20 are arranged inside any of the plurality of air core coils 40, 50, 60. The connection ends drawn out from two adjacent air core coils of the plurality of air core coils 40, 50, 60 are electrically connected to each other. This configuration simplifies the motor configuration and reduces the number of manufacturing steps.

[0046] This configuration also reduces the height of the coil ends that protrude in the axial direction from the yoke 10. This configuration also allows two adjacent air-core coils X0 to be connected, which reduces the number of parts and lowers the resistance of the entire motor, thereby reducing power consumption.

[0047] Although the configurations of the respective embodiments have been described above, the embodiments are not limited thereto. For example, the motors in the respective embodiments are not limited to those with 8 poles and 24 slots, and the number of coils and the number of magnets may be changed. Furthermore, while an example in which the air-core coil X0 is arranged across three magnetic pole portions 20 has been described, the embodiments are not limited thereto. For example, the air-core coil X0 may be arranged across two magnetic pole portions 20, or across four or more magnetic pole portions 20. Furthermore, the number of rows of the air-core coil X0 is also arbitrary, and a configuration may be adopted in which the third row C3 is not formed, or in which a fourth row is additionally formed.

[0048] Furthermore, although the configuration has been described in which adjacent air-core coils X0 in the circumferential direction are directly adjacent to each other without any other magnetic pole portion 20 in between, this is not limited to this, and the air-core coils X0 may be adjacent to each other in the circumferential direction with a predetermined gap between them.

[0049] Furthermore, the motor in each embodiment is, for example, an inner rotor brushless motor, but is not limited to this, and the air core coil X0 in the embodiments may be employed in an outer rotor motor. Furthermore, the stator 2 equipped with the air core coil X0 may be employed in a rotating electrical machine other than a motor, such as a generator.

[0050] Furthermore, the magnetic pole portion 20 may have a shape that includes two ends that protrude in the circumferential direction on the tip side (inner side in the radial direction), for example, if this does not interfere with the placement of the air-core coil X0.

[0051] Furthermore, although the air-core coil X0 is formed using a self-bonding wire in the above-described configuration, it is not limited to this. For example, the coil may be wound around a bobbin and covered with a resin material such as varnish.

[0052] While the present invention has been described above based on the embodiments and modifications, it goes without saying that the present invention is not limited to the embodiments and modifications, and various modifications are possible without departing from the spirit of the present invention. Such modifications without departing from the spirit of the present invention 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]

[0053] 1 motor, 2 stator, 10 yoke, 20 magnetic pole portion, 40 first coil, 50 second coil, 60 third coil, 49, 59, 69 joint portion

Claims

1. a stator; The stator includes: a yoke having a plurality of magnetic pole portions arranged in a circumferential direction; a plurality of air-core coils arranged in a circumferential direction; a plurality of joints; Equipped with the plurality of magnetic pole portions are arranged inside any of the plurality of air-core coils in the circumferential direction, Among the plurality of air core coils, two adjacent air core coils have two connection ends arranged side by side in the circumferential direction, The two connection ends form the joint, The winding directions of the two adjacent air-core coils are opposite to each other. Motor.

2. Among the plurality of air-core coils, In the radial direction, a first group of air core coils forming a first row forms a U phase, In the radial direction, the second group of air-core coils forming a second row form a V-phase, In the radial direction, the air core coils of the third group forming the third row form a W phase. The motor according to claim 1 .

3. The motor according to claim 2 , wherein the first group of air core coils, the second group of air core coils, and the third group of air core coils are arranged at different positions in the circumferential direction.

4. The motor according to claim 2 or 3, wherein the first group of air core coils is not adjacent to the second group of air core coils and the third group of air core coils in the circumferential direction.

5. 5. The motor according to claim 1, wherein the air-core coil is disposed across two or more of the plurality of magnetic pole portions.

6. the connection end of one of the two adjacent air-core coils is the winding start of that one air-core coil, the connection end of the other of the two adjacent air core coils is the winding end of the other air core coil; 6. The motor according to claim 1.

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