Coil unit, coil assembly and energy converter

Abstract

To provide a coil unit that has superior assembling properties and can have its wire bundles arranged to high density.SOLUTION: A coil unit 10 consists of a first air-core coil 1, a second air-core coil 2, and a third air-core coil 3, and a first longitudinal side part 1a, a second longitudinal side part 2a, and a third longitudinal side part 3a are curved along a circumferential surface S, wherein a one end-side first lateral side part 1b is curved along the circumferential surface S, a one end-side second lateral side part 2b is curved along an outer circumferential surface So1 larger in diameter than the circumferential surface S, and a one end-side third lateral side part 3b is curved along an outermost circumferential surface So2 larger in diameter than the outer circumferential surface So1. Further, the second longitudinal side part 2a and the third longitudinal side part 3a are arranged at a first air-core part 1d, the third longitudinal side part 3a and the first longitudinal side part 1a are arranged at a second air-core part 2d, and the first longitudinal side part 1a and the second longitudinal side part 2a are arranged at a third air-core part 3d.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a coil unit composed of a plurality of air-core coils, a coil assembly, and an energy converter using the same. [Background technology]

[0002] Conventional inner rotor coreless motors have many gaps between the coils and in the air-core parts when using air-core coils, and the effective flux area of ​​the coils that is perpendicular to the magnetic flux is underutilized. If the coil flux could be placed in the gaps between the coils or in the air-core parts of air-core coils and effectively utilized, the motor characteristics could be greatly improved.

[0003] Patent Document 1 shows a coil assembly of a stator used in a motor, in which the hollow core of each coil in a frame shape accommodates the vertical side portion (effective coil portion) of another coil. The outer shape of each coil is a split ring shape obtained by dividing a ring into N equal parts, and the angle between the two sides of the split ring shape is 360° / N or less, allowing the coils to be arranged closely together.

[0004] In the coil assembly of Patent Document 1, the cross-sectional shape of the vertical side of each coil (the cross-sectional shape on a plane perpendicular to the axial direction when the direction in which the vertical side extends is the axial direction) is a sector shape as illustrated in the same document. That is, if the cross-sectional area of ​​the vertical side is made wider to improve the characteristics of the motor, the gap between the vertical side parts becomes narrow, so that the coils cannot be assembled from the radial direction when assembled into a stator. In this regard, in the coil assembly of Patent Document 1, the coils are assembled by moving them relatively in the axial direction. However, as the length of the vertical side parts is increased to increase the torque of the motor, the distance by which the coils are moved in the axial direction also increases. That is, in order to assemble this type of coil assembly, the coils must be moved a long distance with almost no radial gap between the coils, which is difficult in terms of assembly. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6864204 [Patent Document 2] JP 2021-141763 A Summary of the Invention [Problem to be solved by the invention]

[0006] Here, Patent Document 2 shows a motor including a coil (first coil) that can be assembled from the radially inner side as the last remaining coil among the multiple coils that make up the coil assembly. However, the cross-sectional shape of the vertical side of the first coil is a substantially parallelogram as shown in the figure, and there is a large gap between the vertical side parts on the radially outer sides of the adjacent vertical side parts. Therefore, the coil assembly of Patent Document 2 is in a situation where the space of this gap cannot be effectively used to improve the characteristics of the motor.

[0007] In view of the above, an object of the present invention is to provide a coil unit, a coil assembly, and an energy converter using the same, which are easy to assemble and allow coil wire bundles to be arranged at high density. [Means for solving the problem]

[0008] The present invention provides a first air core coil having a frame shape and including a pair of first vertical side portions, a one-end first horizontal side portion connecting one end of the first vertical side portions, and an other-end first horizontal side portion connecting the other end of the first vertical side portions, with a first air core portion provided inside the pair of first vertical side portions, the one-end first horizontal side portion, and the other-end first horizontal side portion; a second air core coil having a frame shape and including a pair of second vertical side portions, a one-end second horizontal side portion connecting one end of the second vertical side portions, and an other-end second horizontal side portion connecting the other end of the second vertical side portions, with a second air core portion provided inside the pair of second vertical side portions, the one-end second horizontal side portion, and the other-end second horizontal side portion; and a second air core coil having a frame shape and including a pair of third vertical side portions, a one-end third horizontal side portion connecting one end of the third vertical side portions, and an other-end third horizontal side portion connecting the other end of the third vertical side portions, and a third air core coil having a third air core portion provided inside the third horizontal side portion on the one end side and the third horizontal side portion on the other end side, wherein the first vertical side portion, the second vertical side portion, and the third vertical side portion are curved to follow a predetermined circumferential surface while oriented in a direction along the axis of the predetermined circumferential surface, the first horizontal side portion on the one end side is curved to follow the circumferential surface, the second horizontal side portion on the one end side is curved to follow the outer circumferential surface having a larger diameter than the circumferential surface, and the third horizontal side portion on the one end side is curved to follow the outermost circumferential surface having a larger diameter than the outer circumferential surface, and the second vertical side portion and the third vertical side portion are arranged in the first air core portion, the third vertical side portion and the first vertical side portion are arranged in the second air core portion, and the first vertical side portion and the second vertical side portion are arranged in the third air core portion.

[0009] In the above-mentioned coil unit, it is preferable that the third horizontal edge portion on the other end side is curved to follow the circumferential surface, the second horizontal edge portion on the other end side is curved to follow an inner circumferential surface which has a smaller diameter than the circumferential surface, and the first horizontal edge portion on the other end side is curved to follow an innermost circumferential surface which has a smaller diameter than the inner circumferential surface.

[0010] The present invention also provides a coil assembly in which the above-mentioned coil units are arranged cylindrically along the circumferential surface.

[0011] The present invention also relates to an energy converter in which one or more of the above-mentioned coil units are arranged along the circumferential surface, or which uses the above-mentioned coil assembly. Effect of the Invention

[0012] In the present invention, a single coil unit is formed by the first air core coil, the second air core coil, and the second air core coil, and even when the cross-sectional shapes of the first vertical side portion, the second vertical side portion, and the second vertical side portion are substantially sector-shaped and the gap between them is narrow, these coils can be assembled by moving them in the radial direction. Furthermore, when multiple coil units are used and assembled into a cylindrical shape, they can be assembled by moving the coil units in the radial direction, and the three coils can be handled as a single unit, resulting in excellent workability during assembly. [Brief description of the drawings]

[0013] [Figure 1] 1A to 1C are diagrams showing a schematic view of one embodiment of a first air core coil according to the present invention, in which (a) is a front view, (b) is a longitudinal cross-sectional view along the central axis, and (c) is a view taken along the arrow A. [Diagram 2] 1A is a front view of an embodiment of a second air core coil according to the present invention, FIG. 1B is a longitudinal cross-sectional view taken along the central axis, and FIG. 1C is a view taken along the arrow B. [Diagram 3] 1A to 1C are diagrams showing one embodiment of a third air core coil according to the present invention, in which (a) is a front view, (b) is a longitudinal cross-sectional view along the central axis, and (c) is a view taken along the arrow C. [Figure 4] 4 is a schematic perspective view of a coil unit constituted by the first air core coil, the second air core coil, and the third air core coil shown in FIGS. 1 to 3. FIG. [Diagram 5] FIG. 4 is a diagram showing a modified example in which the arrangement of the coils in the coil unit formed of the first air core coil, the second air core coil, and the third air core coil shown in FIGS. 1 to 3 is changed. [Figure 6]5A is a plan view, FIG. 5B is a cross-sectional view along line DD, and FIG. 5C is a bottom view of a coil assembly in which four coil units shown in FIG. 4 are arranged in a cylindrical shape. [Figure 7] FIG. 7 is a cross-sectional view taken along line EE of the coil assembly shown in FIG. 6. [Figure 8] FIG. 7 is a schematic perspective view of the coil assembly shown in FIG. 6. [Figure 9] 7 is a cross-sectional view of a motor using the coil assembly shown in FIG. 6 as a stator coil. [Figure 10] 10 is a cross-sectional view showing a modified example of the motor shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] An embodiment of the coil unit according to the present invention will be described below. FIG. 4 is a perspective view showing a coil unit 10 of this embodiment. The coil unit 10 is composed of a first air-core coil 1, a second air-core coil 2, and a third air-core coil 3. The coil unit 10 of this embodiment is assembled as a coil assembly 20 by using four of them and arranging them in a cylindrical shape as shown in FIGS. 6, 7, and 8. In the following description, the axial direction is the direction along the central axis (axis O) of the cylindrical coil assembly 20 shown in FIG. 6, the radial direction is the direction perpendicular to the axis O in a plane perpendicular to the axis O, and the circumferential direction is the direction going around the axis O in a plane perpendicular to the axis O.

[0015] The first air core coil 1 is formed into a rectangular frame as shown in FIG. 1(a). Here, the portion extending along the axis O when the first air core coil 1 is assembled into the coil assembly 20 shown in FIG. 6 is referred to as the first vertical side portion 1a. Also, when assembled into the coil assembly 20, the portion located at the upper part and connecting the pair of first vertical side portions 1a is referred to as the one-end first horizontal side portion 1b, and the portion located at the lower part and connecting the pair of first vertical side portions 1a is referred to as the other-end first horizontal side portion 1c. And, the portion of the first air core coil 1 surrounded by the pair of first vertical side portions 1a, the one-end first horizontal side portion 1b, and the other-end first horizontal side portion 1c is referred to as the first air core portion 1d. The width of the first vertical side portion 1a is substantially the same as the widths of the second vertical side portion 2a and the third vertical side portion 3a described later. The width of the first hollow core portion 1d is substantially the same as the widths of a second hollow core portion 2d and a third hollow core portion 3d, which will be described later, and is approximately twice the width of the first vertical side portion 1a.

[0016] 1(b) and 1(c), the first vertical side portion 1a and the first horizontal side portion 1b on one end side are curved to follow a circumferential surface S with a radius R. The first horizontal side portion 1c on the other end side is curved to follow an innermost circumferential surface Si2 with a radius Ri2.

[0017] The second air core coil 2 is shaped like a rectangular frame as shown in Fig. 2(a). Here, a portion of the second air core coil 2 extending along the axis O is referred to as the second vertical side portion 2a. Furthermore, when assembled into the coil assembly 20, a portion located at the upper part and connecting the pair of second vertical side portions 2a is referred to as the one-end second horizontal side portion 2b, and a portion located at the lower part and connecting the pair of second vertical side portions 2a is referred to as the other-end second horizontal side portion 2c. Furthermore, a portion of the second air core coil 2 surrounded by the pair of second vertical side portions 2a, the one-end second horizontal side portion 2b, and the other-end second horizontal side portion 2c is referred to as the second air core portion 2d.

[0018] 2(b) and 2(c), the second vertical side portion 2a is curved to follow a circumferential surface S of radius R. The one end second horizontal side portion 2b is curved to follow an outer circumferential surface So1 of radius Ro1, and the other end second horizontal side portion 2c is curved to follow an inner circumferential surface Si1 of radius Ri1.

[0019] As shown in FIG. 3(a), the third air-core coil 3 is formed in a rectangular frame shape. Here, a portion extending along the axis O in the third air-core coil 3 is referred to as a third longitudinal side portion 3a. Also, when assembled as the coil assembly 20, a portion located upward and connecting a pair of the third longitudinal side portions 3a is referred to as a first-end-side third transverse side portion 3b, and a portion located downward and connecting the pair of the third longitudinal side portions 3a is referred to as a second-end-side third transverse side portion 3c. And a portion surrounded by the pair of the third longitudinal side portions 3a, the first-end-side third transverse side portion 3b, and the second-end-side third transverse side portion 3c in the third air-core coil 3 is referred to as a third air-core portion 3d.

[0020] As shown in FIGS. 3(b) and (c), the third longitudinal side portion 3a and the second-end-side third transverse side portion 3c are curved along a circumferential surface S having a radius R. And the first-end-side third transverse side portion 3b is curved along an outermost circumferential surface So2 having a radius Ro2.

[0021] In this embodiment, the thicknesses of the first air-core coil 1, the second air-core coil 2, and the third air-core coil 3 are all equal. Hereinafter, the thicknesses of the first air-core coil 1, the second air-core coil 2, and the third air-core coil 3 are referred to as a thickness t.

[0022] The above-described radius R and the like satisfy the relationship of Ri2 < Ri1 < R < Ro1 < Ro2. Also, the differences between the respective radii (the difference between Ro2 and Ro1, the difference between Ro1 and R, ···) are set to be larger than the thickness t of the first air-core coil 1 or the like (Ro2 - Ro1 > t, Ro1 - R > t, ···). Here, in FIG. 6 and the like, for example, it is shown that the first-end-side first transverse side portion 1b and the first-end-side second transverse side portion 2b are in contact with each other (so that the differences between the above-described respective radii are equal to the thickness t), but actually there is a slight gap, and these are electrically insulated from each other. Note that, for example, if the surfaces of the first-end-side first transverse side portion 1b and the first-end-side second transverse side portion 2b are covered with an insulating material and have sufficient insulation properties, the first-end-side first transverse side portion 1b and the first-end-side second transverse side portion 2b may be in contact with each other.

[0023] The first air core coil 1, the second air core coil 2, and the third air core coil 3 can be formed, for example, by forming the coil bobbin forming the framework of these coils from synthetic resin or the like, and winding an insulated electric wire around this coil bobbin. Note that the means for forming the first air core coil 1, etc. are not limited to this, and the first air core coil 1, etc. may be formed by preparing a winding frame that will have the shape of the first air core coil 1, etc., winding an insulated electric wire having self-adhesive properties, fusing them together by applying heat or using a solvent, and then removing it from the winding frame (and further adjusting the outer shape to a predetermined shape by press molding as necessary). Alternatively, one type of air core coil may be prepared, and then shaped into the shapes of the first air core coil 1, the second air core coil 2, and the third air core coil 3. As a method for this, a winding frame for a flat air core coil may be prepared, and the flat air core coil may be formed using the insulated electric wire having self-adhesive properties described above, and the first air core coil 1, the second air core coil 2, and the third air core coil 3 may be formed by press molding and curving the flat air core coil using three types of dies.

[0024] After preparing the first air core coil 1, the second air core coil 2, and the third air core coil 3, they can be stacked and fixed to each other as shown in Figures 4 and 5(a) to form the coil unit 10. In Figures 4 and 5(a), the first horizontal side portion 1b on one end, the second horizontal side portion 2b on one end, and the third horizontal side portion 3b on one end are placed facing the same side, and the first air core coil 1, the second air core coil 2, and the third air core coil 3 are stacked in this order such that the second vertical side portion 2a and the third vertical side portion 3a are arranged in the first air core portion 1d, the third vertical side portion 3a and the first vertical side portion 1a are arranged in the second air core portion 2d, and the first vertical side portion 1a and the second vertical side portion 2a are arranged in the third air core portion 3d (see Figure 7), and these are fixed, for example, by an adhesive or the like.

[0025] According to such a coil unit 10, by sequentially supplying current to the first air core coil 1, the second air core coil 2, and the third air core coil 3, the first vertical side portion 1a, the second vertical side portion 2a, and the third vertical side portion 3a can be used as a three-phase electromagnetic coil functioning as effective coil portions.

[0026] In forming the coil unit 10, the method of stacking the first air core coil 1, the second air core coil 2, and the third air core coil 3 is not limited to the above. For example, in the coil unit 10 shown in FIG. 5(a), the first air core coil 1, the second air core coil 2, and the third air core coil 3 are arranged clockwise as shown in the arrow view in a state in which the first horizontal side portion 1b on one end side, the second horizontal side portion 2b on one end side, and the third horizontal side portion 3b on one end side are arranged in this order from the inside to the outside in the radial direction, but the first air core coil 1, the second air core coil 2, and the third air core coil 3 may be arranged counterclockwise as shown in FIG. 5(b). Also, as shown in FIG. 5(c), the first air core coil 1 may be arranged clockwise around the third air core coil 3 and the second air core coil 2 may be arranged counterclockwise, or as shown in FIG. 5(d), the first air core coil 1 may be arranged counterclockwise around the third air core coil 3 and the second air core coil 2 may be arranged clockwise.

[0027] The coil unit 10 of this embodiment can be formed into a coil assembly 20 having a cylindrical shape as a whole by using four of them and arranging them in the circumferential direction as shown in Figs. 6, 7, and 8. According to such a coil assembly 20, the first vertical side portion 1a, etc. are arranged in the order of the first vertical side portion 1a, the second vertical side portion 2a, the third vertical side portion 3a, and the first vertical side portion 1a, etc., as shown in Fig. 7, so that it can be used as a coil for a three-phase motor or a three-phase generator. Also, as shown in Fig. 6(b), the outer peripheral surface of the coil assembly 20, where the other end side first horizontal side portion 1c, etc. are located, does not protrude radially outward, so that when used as a three-phase motor, etc., a cylindrical yoke can be easily inserted from the side where the other end side first horizontal side portion 1c, etc. are located, and this provides excellent workability. Also, the inner peripheral surface of the coil assembly 20, where the one end side first horizontal side portion 1b, etc. are located, does not protrude radially inward, so that when used as a three-phase motor, etc., a rotor can be easily inserted from the side where the one end side first horizontal side portion 1b, etc. are located.

[0028] FIG. 9 shows a motor 30 which is an example of an energy converter using the coil unit 10. The motor 30 includes a stator 31 having a coil assembly 20, and a rotor 32 which rotates with respect to the stator 31. The coil assembly 20 of this embodiment has a first horizontal side portion 1b on one end side and a first horizontal side portion 1c on the other end side covered with a protective portion 33 made of, for example, synthetic resin, and is fixed to a base 34. A bearing 35 is provided on the base 34, and a shaft 36 of the rotor 32 is rotatably held by the bearing 35. The shaft 36 is provided with an inner yoke 37 formed of, for example, pure iron or low carbon steel and positioned radially inside the coil assembly 20, and an outer yoke 39 made of, for example, pure iron and positioned radially outside the coil assembly 20 via a flange portion 38. An inner magnet 40 is provided on the outer peripheral surface of the inner yoke 37, and an outer magnet 41 is provided on the inner peripheral surface of the outer yoke 39.

[0029] In such a motor 30, the inner yoke 37 and inner magnet 40, and the outer yoke 39 and outer magnet 41 are arranged opposite each other on either side of the coil assembly 20, so that when the shaft 36 rotates, no change in magnetic flux occurs inside the inner yoke 37 and outer yoke 39. As a result, iron loss inside the inner yoke 37 and outer yoke 39 is suppressed, making the motor efficient.

[0030] Motor 30A shown in Fig. 10 is obtained by omitting outer magnet 41 from motor 30 shown in Fig. 9. In motor 30A like this, iron loss inside inner yoke 37 and outer yoke 39 can also be suppressed.

[0031] Energy converters using the coil unit 10 or the coil assembly 20 include the above-mentioned three-phase motors and three-phase generators, as well as voice coil motors (VCMs) that use one to three coil units 10 and perform reciprocating motion at a limited angle.

[0032] Although one embodiment of the present invention has been described above, the present invention is not limited to the specific embodiment, and various modifications and changes are possible within the scope of the spirit of the present invention described in the claims unless otherwise specifically limited in the above description. For example, the configuration of the above-mentioned embodiment can be appropriately added or deleted, and the configuration of one embodiment can be applied to another embodiment. Furthermore, the effects of the above-mentioned embodiment are merely examples of the effects resulting from the present invention, and do not mean that the effects of the present invention are limited to the above-mentioned effects.

[0033] For example, the shape of the first air-core coil 1 etc. of this embodiment is not limited to that shown in the figures, and for example, the shape of the first air-core portion 1d etc., which is shown in the figures as being rectangular in plan view, may be an oval shape in which both opposing edges are arc-shaped, or one of the opposing edges may be arc-shaped. Furthermore, the coil unit 10 using the first air-core coil 1 etc. of this embodiment is advantageous in that when assembled into the coil assembly 20, it can be easily inserted into a cylindrical yoke as described above, but the present invention also includes a coil unit 10 in which the other end side third horizontal side portion 3c etc. protrudes radially outward in the same manner as the one end side third horizontal side portion 3b etc. [Explanation of symbols]

[0034] 1: First air core coil 1a: First vertical side 1b: First lateral side on one end side 1c: First horizontal side on the other end side 1d: First air core part 2: Second air core coil 2a: Second vertical side 2b: Second horizontal side on one end 2c: Second horizontal side on the other end side 2d: Second air core part 3: Third air core coil 3a: Third vertical side 3b: Third side part on one end side 3c: Third horizontal side on the other end side 3d: Third hollow core part 10: Coil unit 20: Coil assembly 30, 30A: Motor (energy converter) O: Axis line S: Circumferential surface Si1: Inner circumferential surface Si2: Innermost circumferential surface So1: Outer circumferential surface So2: Outermost circumferential surface

Claims

1. a first air-core coil having a frame shape, a pair of first vertical side portions, a first horizontal side portion on one end connecting one ends of the first vertical side portions, and a first horizontal side portion on the other end connecting the other ends of the first vertical side portions, and a first air-core portion provided inside the pair of first vertical side portions, the first horizontal side portion on one end, and the first horizontal side portion on the other end; a second air-core coil having a frame shape, a pair of second vertical side portions, a one-end second horizontal side portion connecting one ends of the second vertical side portions, and an other-end second horizontal side portion connecting the other ends of the second vertical side portions, and a second air-core portion provided inside the pair of second vertical side portions, the one-end second horizontal side portion, and the other-end second horizontal side portion; a third air-core coil having a frame shape, a pair of third vertical side portions, a one-end third horizontal side portion connecting one ends of the third vertical side portions, and an other-end third horizontal side portion connecting the other ends of the third vertical side portions, and a third air-core portion provided inside the pair of third vertical side portions, the one-end third horizontal side portion, and the other-end third horizontal side portion; the first vertical side portion, the second vertical side portion, and the third vertical side portion are curved along a predetermined circumferential surface while being oriented in a direction along an axis of the predetermined circumferential surface, The one-end first horizontal side portion is curved to follow the circumferential surface, The one-end second horizontal side portion is curved along an outer circumferential surface having a diameter larger than that of the circumferential surface, the one-end-side third horizontal side portion is curved along an outermost circumferential surface having a diameter larger than that of the outer circumferential surface, A coil unit in which the second vertical side portion and the third vertical side portion are arranged in the first air-core portion, the third vertical side portion and the first vertical side portion are arranged in the second air-core portion, and the first vertical side portion and the second vertical side portion are arranged in the third air-core portion.

2. The other end side third horizontal side portion is curved to follow the circumferential surface, The other end side second horizontal side portion is curved along an inner circumferential surface having a smaller diameter than the circumferential surface, The coil unit according to claim 1 , wherein the other end side first horizontal side portion is curved to fit along an innermost circumferential surface that has a smaller diameter than the inner circumferential surface.

3. A coil assembly in which the coil unit according to claim 1 is arranged cylindrically along the circumferential surface.

4. An energy converter comprising one or more coil units according to claim 1 or 2 arranged along the circumferential surface, or using a coil assembly according to claim 3.

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