Rotating Electric Machine

By using protrusions or depressions on the bobbin to regulate the position of rectangular cross-section electric wires, the winding structure in split-core motors achieves improved insulation and efficiency, addressing the positional deviations and protrusions in existing technologies.

JP7621131B2Active Publication Date: 2025-01-24HITACHI LTD
View PDF 4 Cites 0 Cited by

Patent Information

Application Number
JP2021022170
Authority / Receiving Office
JP · JP
Patent Type
Patents
Current Assignee / Owner
Filing Date
2021-02-15
Publication Date
2025-01-24
Estimated Expiration
2041-02-15

AI Technical Summary

Technical Problem

In split-core concentrated winding motors using rectangular cross-section electric wires, the coil position is not regulated, leading to deviations and protrusions that compromise insulation performance and assembly, especially with square cross-section electric wires.

Method used

A rotating electric machine with a stator featuring a bobbin that has protrusions or depressions at predetermined locations to restrict the movement of rectangular cross-section electric wires, ensuring they stay within the insulation boundary and maintain proper positioning.

Benefits of technology

This solution prevents positional shifts of the electric wires, allowing for dense winding and improved insulation, resulting in high efficiency and output of the motor.

✦ Generated by Eureka AI based on patent content.

Smart Images

  • Figure 0007621131000001
    Figure 0007621131000001
  • Figure 0007621131000002
    Figure 0007621131000002
  • Figure 0007621131000003
    Figure 0007621131000003
Patent Text Reader

Abstract

To prevent displacement of an electric wire of a split core using an electric wire coil with an angular cross section.SOLUTION: A rotary electric machine includes a rotor 2 and a stator 1 having teeth including a bobbin 4 and a multilayer coil 5 in which a wire with a square cross section is wound around the bobbin. The multilayer coil has a first layer and a second layer formed adjacent to the outside of the first layer. A depression or projection 12 is formed at a predetermined location in the first layer, the first turn of the second layer is positioned outside the terminal turn of the first layer, and the depression or projection of the first layer restricts the movement of at least some of the teeth of the first turn of the second layer in the elongation direction.SELECTED DRAWING: Figure 6
Need to check novelty before this filing date? Find Prior Art

Description

[Technical field]

[0001] The present invention relates to a rotating electric machine, and more particularly to a winding structure of a core that constitutes a stator of a motor. [Background technology]

[0002] One known type of motor is an epicyclic motor, in which a rotor supported by bearings on the outer periphery of a stator rotates. The stator is made up of multiple cores (split cores) assembled in the circumferential direction. A bobbin made of insulating material is attached to the split core, and a coil of enameled wire with a round or square cross section is wound around the bobbin to form split magnetic poles. The stator is made up of these multiple split magnetic poles assembled in a ring shape. Meanwhile, the rotor is made up of a permanent magnet such as a rare earth or ferrite fixed to the inside of the ring member. The rotor rotates when different phase currents are passed through the stator coils, converting electrical energy into mechanical energy. The winding structure of the stator and the bobbin is disclosed in, for example, Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-20875 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a split-core concentrated winding motor using rectangular cross-section wire for the coil, the split cores 3 are arranged so that the rectangular cross-section wire is at its maximum density within the trapezoidal cross section defined by the three planes defined by the bobbin 4 and the insulation boundary line 9 of the adjacent split cores 3, as shown in Fig. 1. In this case, jump lines 10a, 10b (collectively indicated as 10) that skip the wire by several turns are formed at the axial end of the split core 3. (Fig. 1(b) is a view taken along the line AA in (a).) In the winding structure of the bobbin, in the case of a round cross-section electric wire, the position of the coil surface can be controlled by the valleys of the electric wires that make up the coils in the lower layer, but in the case of a rectangular cross-section electric wire, there is no means to control the position of the coil surface. Therefore, due to the tension during winding, the jump wires 10 are stretched to take the shortest route, and deviations from the ideal position occur, as shown in jump wires 10a and 10b in Figure 1(a). As a result, as shown in Figure 1(b), a protrusion 91 is generated in which the jump wires 10 protrude beyond the insulation boundary line 9 of the split core 3. In this state, the insulation performance required for the motor cannot be satisfied, and in the worse case, there is a problem that the split magnetic poles cannot even be assembled in the circumferential direction.

[0005] An object of the present invention is to prevent misalignment of wires in a split core using a rectangular cross-section electric coil, more specifically, to suppress movement of the rectangular cross-section electric coil due to jump wires in a split core motor with concentrated winding. [Means for solving the problem]

[0006] A preferred example of a rotating electric machine according to the present invention is a rotating electric machine including a stator having teeth including a bobbin and a multilayer coil in which a rectangular cross-section electric wire is wound around the bobbin, and a rotor, The multi-layer coil has a first layer and a second layer formed adjacent to an outer side of the first layer, A depression or a protrusion is formed at a predetermined location of the first layer, This is a rotating electric machine in which the initial turn of the second layer is located outside the terminal turn of the first layer, and the depression or protrusion of the first layer limits the movement of at least a portion of the initial turn of the second layer in the extension direction of the teeth.

[0007] In a preferred example, a protrusion is provided at least on a corner of the bobbin, and the recess or protrusion in the first layer is formed by the protrusion.

[0008] In a preferred example, a plurality of the projections are provided in parallel in the winding direction of the multi-layer coil on both opposing side surfaces of the bobbin.

[0009] In a preferred example, the terminal turn of the first layer and the initial turn of the second layer of the rectangular cross-section electric wire are connected via a jump wire, and the jump wire is in contact with the depression or protrusion. Effect of the Invention

[0010] According to the present invention, it is possible to prevent misalignment of the rectangular cross-section electric wire on the side of the coil and to arrange the flying wire spanning multiple turns on one end face of the coil in the axial direction. As a result, it is possible to obtain a coil of rectangular cross-section electric wire wound densely within a trapezoidal winding range by keeping the wire on the side of the coil, which is an extension of the flying wire, within the insulation boundary, and to realize a motor with high efficiency and high output. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing a winding structure of a bobbin in the prior art. [Diagram 2] FIG. 1 is a diagram showing the configuration of an epidural motor. [Diagram 3] FIG. 2 is a cross-sectional view of the stator taken along a direction perpendicular to the rotation axis of the rotor. [Figure 4] FIG. 2 is a perspective view showing a bobbin according to the first embodiment. [Diagram 5] FIG. 2 is a perspective view showing a winding structure of a bobbin in the first embodiment. [Figure 6] 4A to 4C are diagrams showing a process of winding a wire around a bobbin in the first embodiment. [Figure 7] FIG. 4 is a diagram for explaining the width dimension of a protrusion of a bobbin in the first embodiment. [Figure 8] 10A to 10C are diagrams showing a process of winding a wire around a bobbin in the second embodiment. [Figure 9] FIG. 10 is a diagram for explaining the width dimension of a protrusion of a bobbin in the second embodiment. [Figure 10] FIG. 4 is a diagram for explaining the height dimension of a bobbin protrusion. [Figure 11] FIG. 4 is a diagram for explaining the dimensions of the corner radius of a bobbin protrusion. [Figure 12] FIG. 4 is a diagram for explaining the dimensions of corners of a bobbin protrusion. [Figure 13] 13A to 13C are diagrams showing a winding procedure in the third embodiment. [Figure 14] FIG. 11 is a diagram illustrating the width dimension of a winding in the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. EXAMPLES

[0013] Figure 2 shows the structure of an epidromic motor. An epidromic motor is composed of a stator 1 and a rotor 2 that rotates while being supported by bearings on the outer periphery of the stator 1.

[0014] 3, the stator 1 is formed by arranging multiple split magnetic poles 6 in the circumferential direction, and housing the coil 5 in a trapezoidal cross-sectional space defined by three planes defined by the bobbin 4 and the insulating boundary lines 9 of adjacent split cores 3. The split cores 3 are generally formed by punching out electromagnetic steel sheets with a thickness of about 0.1 mm to 0.5 mm (the surface has an insulating film to prevent electrical current passing through it) and laminating them by crimping, welding, or bonding with resin.

[0015] In a split-core concentrated winding motor using a square cross-section wire for the coil 5, the square cross-section wire is arranged in this trapezoidal cross-section so as to be at maximum density. At the end of the axial direction (direction A in Fig. 2) of the split core 3, a jump line 10 (two points 10a and 10b in Fig. 6) is formed, which moves the wire by skipping several turns. The more wire with a larger unit conductor cross-sectional area is wound in the trapezoidal space with the same number of turns, the less copper loss there is, and the more efficient the motor becomes. On the other hand, the more ampere turns can be obtained by increasing the number of turns for the same unit conductor area, and the more the motor output increases. Therefore, the efficiency and output of the motor can be increased by increasing the ratio of the conductor area in the trapezoidal cross-section formed by the three planes constituting the bobbin 4 and the insulation boundary line 9 of the adjacent split core 3.

[0016] FIG. 4 shows the configuration of the bobbin 4. The bobbin 4 is quadrilaterally made of an insulating material such as PBT or LCP, and an electric wire (winding) such as an enameled wire is wound around the outer periphery to form a quadrilateral coil (rectangular cross-section electric wire coil), and the hollow portion 42 is assembled to the split core 3. Fig. 5 shows the bobbin 4 with the rectangular cross-section electric wire coil 5 formed thereon attached to the split core 3.

[0017] A characteristic feature is that two protrusions 411, 413, 412, 414 (collectively referred to as 41) are provided on each of the two opposing outer side surfaces of the bobbin 4 in parallel to the axial direction (i.e., the direction of the rotation axis of the rotor 2). These protrusions 4 form protrusions on the winding layers of the rectangular cross-section electric wire, suppressing misalignment of the coil side surface, particularly the movement of the flying wires of the rectangular cross-section electric wire coil in the extension direction of the teeth. The number of protrusions formed on one side surface corresponds to the number of flying wires 10 occurring on that surface. For example, the two protrusions 412, 414 engage with the two flying wires 10a, 10b (FIG. 5) to limit their misalignment.

[0018] The reason for forming protrusions 41 on the outer surfaces of the two opposing side surfaces of the bobbin 4 is to accommodate the case where the wire is wound clockwise from the right and the case where the wire is wound counterclockwise from the left. That is, in the illustrated example, one bobbin 4 can accommodate both clockwise and counterclockwise windings. Note that, in the case of only clockwise or counterclockwise windings, it is sufficient to have a protrusion on only one of the two opposing side surfaces of the bobbin 4.

[0019] In addition, the protrusions 41 do not need to have a continuous structure in the axial direction, and may have, for example, a discontinuous structure. In order to significantly prevent the positional deviation of the jump line, it is preferable to provide the protrusions 41 at least on the corners of the bobbin 4.

[0020] Next, the process of winding the wire around the bobbin will be described with reference to FIG. Here, the position of the protrusion 41 in the winding advancement direction is set at a position one turn before the end position of the flying wire 10. The winding process is carried out in the following steps (1) to (8), where (1) to (8) indicate the state of the coil end at each stage.

[0021] (1) The state of the bobbin 4 before winding. (2) The first layer is wound from the bottom (split core 3 side) to the top (winding progression direction (X direction)). At this time, protrusions 12 are formed by the winding on top of the four protrusions 41. (3) The winding is folded back at the upper end, and the second layer is wound from top to bottom (Y direction (opposite direction to X direction)). The second layer of projections 13 are formed on top of the projections of the first layer. (4) A first flying line 10a is formed from the lower end. Here, the end of the first flying line 10a is hooked onto the protrusion 13a of the second layer and positioned. (5) The third layer is wound from the end position of the first flying line 10a from below toward above (in the X direction). At this time, the protrusions 14 of the third layer are formed on the protrusions 13b of the second layer. (6) The winding is folded back at the upper end, and the fourth layer is wound from top to bottom. At this time, the fourth layer projection 15 is formed on the third layer projection 14. (7) A second jump line 10b is formed from the lower folded end. Here, the end of the second jump line 10b is hooked onto the protrusion 15b of the fourth layer and positioned. (8) Finally, wind from the end position of the second flying wire 10b upwards and finish at the upper end. The finally wound bobbin 4 looks like FIG.

[0022] As described above, the end of the jump wire 10 is hooked on the protrusions 13a, 15b formed by winding the coil 5 around the protrusion 41 on the side of the bobbin 4, thereby regulating the position of the coil and suppressing misalignment of the rectangular cross-section electric wire. This allows the jump wires 10a, 10b to be formed on one end face in the axial direction of the coil 5, and the electric wire on the side of the coil to be contained inside the insulation boundary line.

[0023] Here, as shown in FIG. 7, by setting the width Wp of the protrusion 41 of the bobbin 4 smaller than the minimum width Wc of the rectangular cross-section electric wire 16, it becomes possible to wind the coil on the upper layer of the bobbin without any gaps, in response to the manufacturing dimensional error of the rectangular cross-section electric wire 16. EXAMPLES

[0024] A second embodiment will be described with reference to FIGS. The second embodiment uses the same bobbin 4 (FIG. 4) as the first embodiment, but is different in that the position of the protrusion 41 in the winding advancement direction is set at the end position of the flying wire 10. The other configurations are the same as those of the first embodiment. The winding process will be described below with reference to Fig. 8. (1) to (8) show the state of the coil end at each stage.

[0025] (1) The state of the bobbin 4 before winding. (2) The first layer is wound from the bottom (split core 3 side) to the top (X direction). At this time, protrusions 12 are formed by the winding on top of the four protrusions 41. (3) The winding is folded back at the top end, and the second layer is wound from top to bottom (Y direction). Here, after the second layer is wound, the flying wire 10a is formed, and the recess 17a is formed avoiding the protrusion 12a which is the end position of the flying wire 10a. In the third layer, the rectangular cross-section wire is wound around the protrusion 41 in the place where the flying wire 10a is not formed, to form the protrusion 13 of the second layer. (4) First flying line 10a is formed from the lower end. Here, the end of first flying line 10a is embedded and positioned in depression 17a of the first layer. (5) The third layer is wound from the end position of the first flying line 10a from below toward above (in the X direction). At this time, protrusions 14 of the third layer are formed on the protrusions 13 of the second layer. (6) The winding is turned back at the upper end, and the fourth layer is wound from top to bottom. At this time, a jump line is formed after the fourth layer is wound, and a recess 18b is formed to avoid the protrusion 14b which is the end position of the jump line. (7) A second jump line 10b is formed from the lower folded end. Here, the end of the second jump line 10b is embedded and positioned in the depression 18b of the third layer. (8) Finally, wind upward (in the X direction) from the end position of the second jump wire 10b and finish at the upper end.

[0026] As described above, the end portions of the jump wires 10a and 10b are embedded in the depressions 17a and 18b formed by winding around the protrusions 41 on the side surface of the bobbin 4 while avoiding the protrusions 12a and 14b, so that the position is regulated, and the displacement of the square cross-section wire can be suppressed. Thereby, the jump wire 10 can be formed on one end surface in the axial direction of the coil 5, and the wire on the side surface of the coil can be housed inside the insulation boundary line.

[0027] Here, as shown in FIG. 9, by setting the width Wp of the protrusion 41 of the bobbin 4 to be larger than the maximum width of the width Wc of the square cross-section wire 16, corresponding to the manufacturing dimensional error of the square cross-section wire 16, the width Wg of the depression 17a formed in the second layer can be made smaller than the width Wc of the square cross-section wire 16, and the end portion of the jump wire 10a can be inserted into the depression to obtain a stable fixing force.

[0028] What can be said in common for both Example 1 and Example 2 is that, as shown in FIG. 10(a) compared to FIG. 10(b), by making the height hp of the protrusion 41 of the bobbin larger than the minimum radius r of the corner portion of the square cross-section wire 16 (r < hp), the displacement of the square cross-section wire 16 in the winding progress direction with respect to the protrusion 41 can be made smaller.

[0029] Also, what can be said in common for both Example 1 and Example 2 is that, as shown in FIG. 11(a) compared to FIG. 11(b), if the corner radius rp of the protrusion 41 of the bobbin 4 is made smaller than the corner radius rb of the surface of the bobbin 4 other than the protrusion, the area of the protrusion 41 that restrains the end portion of the jump wire becomes larger, so that a stable jump wire positioning effect can be obtained.

[0030] Further, if the corner shape of the protrusion 41 of the bobbin 4 is an elliptical shape with the long side a (= rb + hp) in the height direction of the protrusion and the short side b in the direction perpendicular to the height of the protrusion 41, and the short side b is made smaller than the corner radius rb of the surface of the bobbin 4 other than the protrusion, the area of the protrusion 41 that restrains the end portion of the jump wire becomes larger as well, so that the positioning effect of the end portion of the jump wire can be enhanced.

Example

[0031] Example 3 will be described with reference to Figures 13 and 14. In Example 3, instead of providing the protrusions 41 on the bobbin 4 as in Example 1, a recess is formed in the winding layer by improving the winding structure, and the winding is positioned with respect to the flying wires by using this recess. The winding process will be described below with reference to Fig. 13. (1) to (8) show the state of the coil end at each stage.

[0032] (1) The state of the bobbin 4 before winding. (2) Wind the first layer from the bottom (split core 3 side) to the top (X direction). (3) The winding is folded back at the upper end, and the second layer is wound from top to bottom (Y direction). After the second layer is wound, a flying wire 10a is formed, and a recess 17a is formed by avoiding the end position of the flying wire 10a. Here, the recess 17a is formed by winding the wire 16 on the side of the bobbin 4 with a gap of one wire, as shown in FIG. (4) First flying lines 10a are formed from the lower end. Here, the end of first flying line 10a is embedded and positioned in depression 17a of the second layer. (5) From the end position of the first jump line 10a, wind the third layer from bottom to top (X direction). (6) The winding is turned back at the upper end, and the fourth layer is wound from top to bottom. At this time, a jump line is formed after the fourth layer is wound, and a recess 18b is formed at the end position. (7) The second flying wire 10b is formed from the lower folded end. Here, the wire is wound around the side surface of the bobbin 4 with a space for one wire to form a recess 18b. The end of the second flying wire 10b is embedded and positioned in the recess 18b of the third layer. (8) Finally, wind upward (in the X direction) from the end position of the second jump wire 10b and finish at the upper end.

[0033] As described above, by embedding the end portions of the jump wires 10a, 10b in the recesses 17a, 18b formed by winding the electric wire at intervals of one wire on the side surface of the bobbin 4, the end positions of the jump wires can be restricted and the electric wires can be prevented from shifting. As a result, the jump wire 10 can be formed on one end surface in the axial direction of the coil 5, and the electric wire on the side surface of the coil can be contained inside the insulation boundary line.

[0034] Although the above embodiment has been described with reference to a concentrated winding motor having an outer rotor type divided core, the present invention can also be applied to a concentrated winding motor having an inner rotor type divided core. [Explanation of symbols]

[0035] 1: Stator 2: Rotor 3: Split core 4: Bobbin 41: Protrusion 5: Coil 6: Split magnetic pole 9: Insulation boundary 10: Flying lines 12: Protrusion from first layer winding 13: Protrusion due to second layer winding 14: Protrusion due to third layer winding 15: Protrusion due to fourth layer winding 16: Square cross section electric wire 17: Depression of second layer winding 18: Depression of the fourth layer winding

Claims

1. A rotating electric machine having a stator having teeth including a bobbin and a multi-layer coil in which a rectangular cross-section electric wire is wound around the bobbin, and a rotor, The multi-layer coil has a first layer and a second layer formed adjacent to an outer side of the first layer, A depression or a protrusion is formed at a predetermined location of the first layer, The terminal turn of the first layer and the initial turn of the second layer of the rectangular cross-section electric wire are connected via a jump wire, and the jump wire is in contact with the depression or the protrusion, The initial turn of the second layer is located outside the terminal turn of the first layer, and the depression or protrusion of the first layer limits movement of at least a portion of the initial turn of the second layer in the extension direction of the teeth, A protrusion is provided at least on a corner of the bobbin, the protrusions in the first layer are formed by the protrusions provided on the bobbin; The number of the protrusions generated on the first layer corresponds to the number of the jump lines. Rotating electric motor.

2. A rotating electric machine having a stator having teeth including a bobbin and a multi-layer coil in which a rectangular cross-section electric wire is wound around the bobbin, and a rotor, The multi-layer coil has a first layer and a second layer formed adjacent to an outer side of the first layer, A depression or a protrusion is formed at a predetermined location of the first layer, The terminal turn of the first layer and the initial turn of the second layer of the rectangular cross-section electric wire are connected via a jump wire, and the jump wire is in contact with the depression or the protrusion, The initial turn of the second layer is located outside the terminal turn of the first layer, and the depression or protrusion of the first layer limits movement of at least a portion of the initial turn of the second layer in the extension direction of the teeth, a plurality of projections, the same number of which are provided on each of the opposing side surfaces of the bobbin, in parallel to the winding direction of the multilayer coil; the protrusions in the first layer are formed by the plurality of protrusions provided on the bobbin; The number of the protrusions generated on the first layer corresponds to the number of the jump lines. Rotating electric motor.

3. The end of the flying wire is embedded in a recess formed by winding the rectangular cross-section electric wire around the protrusion formed on the side surface of the bobbin, the recess being formed to avoid the protrusion of the first layer. The rotating electric machine according to claim 1.

4. The multilayer coil has a third layer which is a bottom layer located on the inner side adjacent to the first layer, The initial turn of the third layer is located inside the end turn of the third layer, and the third layer has a protrusion formed by winding the rectangular cross-section electric wire around the protrusion of the bobbin, 3. The rotating electric machine according to claim 1, wherein the projections of the first layer are formed by winding the rectangular cross-section electric wire around the projections of the third layer.

5. The rectangular cross-section wire is a wire whose width varies due to manufacturing errors, 5. The rotating electric machine according to claim 4, wherein the width of said projection of said bobbin is equal to or smaller than the minimum width of said rectangular cross-section electric wire.

6. The multilayer coil includes a third layer, which is a bottom layer located on an inner side adjacent to the first layer, The initial turn of the third layer is located inside the end turn of the third layer, and the third layer has a protrusion formed by winding the rectangular cross-section electric wire around a protrusion of the bobbin, 2. The rotating electric machine according to claim 1, wherein the turns of the rectangular cross-section electric wire are spaced above the protrusions of the third layer to form the recesses of the first layer.

7. The rectangular cross-section wire is a wire whose width varies due to manufacturing errors, 7. The rotating electric machine according to claim 6, wherein a width of said projection of said bobbin is equal to or greater than a maximum width of said rectangular cross-section electric wire.

8. The corner of the rectangular cross-section wire is rounded with a first radius, 2. The rotating electric machine according to claim 1, wherein the height of said projection of said bobbin is equal to or greater than said first radius.

9. 2. The rotating electric machine according to claim 1, wherein the radius of the corners of said projections of said bobbin is equal to or smaller than the radius of the corners of the winding body of said bobbin.

10. 5. The rotating electric machine according to claim 4, wherein the corner of said projection of said bobbin is elliptical, and at least one side of said ellipse is equal to or smaller than the radius of the corner of said winding body of said bobbin.

11. A rotating electric machine having a stator having teeth including a bobbin and a multi-layer coil in which a rectangular cross-section electric wire is wound around the bobbin, and a rotor, No protrusions are formed on the side surface of the bobbin, The multi-layer coil has at least a first layer and a second layer formed adjacent to the outside of the first layer, The terminal turn of the first layer and the initial turn of the second layer of the rectangular cross-section electric wire are connected via a jump wire, The rectangular cross-section electric wire is wound around a side surface of the bobbin with an interval of one electric wire therebetween to form a recess, and the end portion of the flying wire is embedded in the recess; A rotating electric machine, wherein the initial turn of the second layer is located outside the terminal turn of the first layer, and the recess of the first layer limits movement of at least a portion of the initial turn of the second layer in the extension direction of the teeth.

Citation Information

Patent Citations

  • Stator and its manufacturing method

    JP2005020875A

  • Stator and its manufacturing method

    JP2008148515A

  • Winding structure of rotating electrical machine

    JP2009118574A

  • Rotary electric machine and vehicle

    JP2011036092A