Axial gap rotating electric machine

Abstract

An object of the present invention is to provide an axial gap rotary electric machine capable of improving productivity of a stator core.SOLUTION: An axial gap type rotary electric machine 100 includes a rotor 2 provided with a plurality of magnetic poles 26, a multi-phase stator core 3 facing the magnetic poles 26 in an axial direction, and a coil 8 provided in the stator core 3. The stator core 3 of each phase has a magnetic path member 5 including a plurality of facing portions 36 facing the magnetic poles 26 and a connection portion 34 connecting the facing portions 36 to each other, and the connection portion 34 is connected from one facing portion of the plurality of facing portions 36 to two facing portions adjacent in the circumferential direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an axial gap type rotating electric machine. [Background technology]

[0002] A rotating electric machine having a rotor and a stator arranged opposite to each other is known. In Patent Document 1, the present applicant disclosed an axial gap type rotating electric machine including a rotor having a magnet with multiple magnetic poles, a stator core axially facing the multiple magnetic poles, and a coil attached to the stator core. The stator core has multiple magnetic path members for passing magnetic flux from the magnetic poles, and the multiple magnetic path members are magnetically independent from each other. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2024-040653 Summary of the Invention [Problem to be solved by the invention]

[0004] The inventors have studied axial gap type rotating electric machines and have recognized that the rotating electric machine described in Patent Document 1 has disadvantages in terms of productivity because the height of the yoke portion for passing magnetic flux from the magnetic poles differs for each phase and the shape of the magnetic path member differs for each phase. In other words, there is room for improvement in conventional rotating electric machines from the viewpoint of improving the productivity of stator cores.

[0005] SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide an axial gap type rotating electric machine that can improve the productivity of stator cores. [Means for solving the problem]

[0006] To solve the above problems, an axial gap type rotating electric machine according to one embodiment of the present invention includes a rotor provided with multiple magnetic poles, a multiple-phase stator core axially facing the magnetic poles, and coils provided in the stator core. Each stator core has a magnetic path member including multiple opposing portions facing the magnetic poles and connection portions connecting the opposing portions. The connection portions are connected from one of the multiple opposing portions to two opposing portions adjacent in the circumferential direction.

[0007] Any combination of the above components, or mutual substitution of the components or expressions of the present invention between methods, systems, etc., are also valid aspects of the present invention. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide an axial gap type rotating electric machine that can improve the productivity of stator cores. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a side view showing an axial gap type rotating electric machine according to an embodiment; [Figure 2] FIG. 2 is a plan view showing the stator of FIG. [Figure 3] FIG. 2 is a plan view showing the stator core of FIG. [Figure 4] 4 is a plan view showing a U-phase stator core of FIG. 3. FIG. [Figure 5] 5 is a diagram showing a magnetic path member of the stator core of FIG. 4. [Figure 6] FIG. 10 is a side view showing an axial gap type rotating electric machine according to a first modified example. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described below based on preferred embodiments with reference to the drawings. In the embodiments and modifications, identical or equivalent components and members are designated by the same reference numerals, and redundant explanations will be omitted where appropriate. The dimensions of the members in the drawings are enlarged or reduced as appropriate to facilitate understanding. Some members that are not important for explaining the embodiments will be omitted from the drawings.

[0011] Furthermore, terms including ordinal numbers such as first and second are used to describe various components, but these terms are used only to distinguish one component from another and do not limit the components.

[0012] [Embodiment] The configuration of an axial gap type rotating electric machine 100 (hereinafter sometimes referred to as "rotating electric machine 100") according to an embodiment will be described with reference to the drawings. In this specification, an electric machine having a rotating part is referred to as a "rotating electric machine," and the term "rotating electric machine" includes electric motors, generators, and electric motor / generator combinations. The rotating electric machine 100 in this example can be used as an electric motor, a generator, or an electric motor / generator combination.

[0013] FIG. 1 is a side view showing an example of a rotating electric machine 100. FIG. 2 is a plan view showing a stator 4 of the rotating electric machine 100. The stator core 3 in FIG. 1 is shown in cross section along line XX in FIG. 2. The rotating electric machine 100 includes a rotor 2 and a stator 4. The rotor 2 is rotatable about a rotation axis La. Hereinafter, a direction parallel to the rotation axis La will be referred to as the axial direction, a direction perpendicular to the rotation axis La in a plane perpendicular to the rotation axis La will be referred to as the radial direction, and a circumferential direction of a circle centered on the rotation axis La will be referred to as the "circumferential direction." In the axial direction, the side of the stator 4 on which the rotor 2 is mounted will sometimes be referred to as the "upper" side, and the opposite side will sometimes be referred to as the "lower" side. These directional notations do not limit the orientation of the rotating electric machine 100, and the rotating electric machine 100 can be used in any orientation.

[0014] The rotating electric machine 100 includes a rotor 2 provided with a plurality of magnetic poles 26, a multi-phase stator core 3 axially facing the magnetic poles 26, and coils 8 provided in the stator core 3. The rotating electric machine 100 is an axial gap motor in which the rotor 2 and the stator 4 face each other axially via an air gap. The rotor 2 is supported by the stator 4 by bearing means 28 so as to be rotatable about the rotation axis La.

[0015] The rotor 2 has a rotor yoke 22, an annular magnet 24, and a shaft 12. The rotor yoke 22 is a disk having soft magnetic properties. The shaft 12 is a rod-shaped stainless steel member extending along the rotation axis La, is disposed through the center of the rotor yoke 22, and is fixed to the rotor yoke 22.

[0016] The magnet 24 is fixed to the underside of the rotor yoke 22, for example, by adhesive. The magnet 24 has a plurality of magnetic poles 26 that function as driving magnetic poles on the surface axially facing the stator core 3. For example, the plurality of magnetic poles 26 are four magnetic poles arranged at predetermined intervals in the circumferential direction. As an example, the magnet 24 in this embodiment is a neodymium magnet whose main components are neodymium, iron, and boron. The magnet 24 supplies magnetic flux F from the magnetic poles 26 to the magnetic path of the stator core 3.

[0017] The stator 4 has a stator support member 32, a multi-phase stator core 3, and multi-phase coils 8. In this embodiment, the stator cores 3 have U-phase, V-phase, and W-phase stator cores. Hereinafter, when the U-phase, V-phase, and W-phase are to be distinguished, U, V, and W are added to the end of the reference numeral; otherwise, no addition is made. The stator support member 32 is a disk-shaped member having a surface facing the magnet 24, and is made of a non-magnetic material. Examples of the non-magnetic material that can be used include resin, carbon, glass, non-magnetic metal, and ceramic.

[0018] As shown in FIG. 2 , the stator core 3 of this embodiment is made up of magnetic path members 5. The magnetic path member 5 for each phase is made up of four magnetic path members, namely, magnetic path members 51, 52, 53, and 54. Therefore, the stator core 3 includes magnetic path members 51U, 51V, 51W, 52U, 52V, 52W, 53U, 53V, 53W, 54U, 54V, and 54W. A coil 8U is attached to the magnetic path members 51U, 52U, 53U, and 54U. A coil 8V is attached to the magnetic path members 51V, 52V, 53V, and 54V. A coil 8W is attached to the magnetic path members 51W, 52W, 53W, and 54W.

[0019] See also Figures 3, 4, and 5. Figure 3 is a plan view showing the stator core 3 of the rotating electric machine 100. Figure 4 is a plan view showing the U-phase stator core 3U. Figure 5 is a diagram showing the magnetic path member 5 of the stator core 3. The magnetic path member 5 in Figure 5 shows magnetic path member 51 of the four magnetic path members, but the other magnetic path members 52, 53, and 54 are the same as magnetic path member 51.

[0020] In the embodiment, the U-phase, V-phase, and W-phase stator cores 3U, 3V, and 3W are composed of a plurality of magnetic path members 5 of the same shape. In this specification, the term "same shape" includes not only cases where the shapes are strictly the same, but also cases where there are differences due to manufacturing errors or cases where the shapes can be determined to be identical by visual inspection. Therefore, the V-phase and W-phase stator cores 3V and 3W are also the same shape as the stator core 3U. Below, the U-phase stator core 3U will be described, but the same applies to the stator cores 3V and 3W of the other phases. In this example, the stator core 3U is composed of four magnetic path members 5.

[0021] The magnetic path members 5 function as a magnetic path for passing magnetic flux F supplied from the magnetic poles 26. The four magnetic path members 5 are fixed to the stator support member 32 using an adhesive at predetermined angles (for example, 90°) in the circumferential direction. As shown in FIG. 1 , the magnetic flux F from the magnetic poles 26 flows into one of the opposing portions 361, flows through the connection portion 34, flows out from the other opposing portion 362, and flows into the magnetic poles 26 on the opposite side. The coils 8 are disposed in the opposing portions 361 or the connection portion 34. The position of the coils 8 can be determined by experiment or simulation to achieve desired characteristics.

[0022] The stator core 3 can be manufactured from various known magnetic materials such as plate material, foil material, and powder material. In this embodiment, the facing portion 36 and the connecting portion 34 include soft magnetic wires 41. The facing portion 36 and the connecting portion 34 are formed by bundling a plurality of soft magnetic wires 41. The soft magnetic wires 41 will be described later. By being formed from the soft magnetic wires 41, the stator core 3 can freely change the shape of the outer contour of a cross section cut along a plane perpendicular to the extension direction of the soft magnetic wires 41. The cross-sectional shapes of the facing portion 36 and the connecting portion 34 may be the same or different.

[0023] The stator core 3 has a magnetic path member 5 including a plurality of opposing portions 36 that face the magnetic poles 26 and a connecting portion 34 that connects the opposing portions 36 together. The connecting portion 34 extends bifurcated from one of the plurality of opposing portions 36 and is connected to two opposing portions 36 that are adjacent in the circumferential direction.

[0024] The facing portion 362 is disposed at a position 90° circumferentially away from the facing portion 361 in a clockwise direction, the facing portion 363 is disposed at a position 90° circumferentially away from the facing portion 362 in a clockwise direction, and the facing portion 364 is disposed at a position 90° circumferentially away from the facing portion 363. Therefore, the facing portion 364 is disposed at a position 90° circumferentially away from the facing portion 361 in a counterclockwise direction.

[0025] The connection portion 34 includes a connection portion 341 connecting the opposing portion 361 and the opposing portion 362, a connection portion 342 connecting the opposing portion 362 and the opposing portion 363, a connection portion 343 connecting the opposing portion 363 and the opposing portion 364, and a connection portion 344 connecting the opposing portion 364 and the opposing portion 361. The connection portions 341 and 344 are connected from the opposing portion 361 to the two opposing portions 362 and 364 that are adjacent in the circumferential direction, the connection portions 342 and 341 are connected from the opposing portion 362 to the two opposing portions 361 and 363 that are adjacent in the circumferential direction, the connection portions 343 and 342 are connected from the opposing portion 363 to the two opposing portions 364 and 362 that are adjacent in the circumferential direction, and the connection portions 344 and 343 are connected from the opposing portion 364 to the two opposing portions 363 and 361 that are adjacent in the circumferential direction.

[0026] As described above, the magnetic path member 5 functions as a magnetic path that allows the magnetic flux F from the magnetic pole 26 to pass through, and constitutes the stator core 3. The magnetic path member 5 includes a magnetic path member 51 provided with the facing portion 361, the facing portion 362, and the connecting portion 341, a magnetic path member 52 provided with the facing portion 362, the facing portion 363, and the connecting portion 342, a magnetic path member 53 provided with the facing portion 363, the facing portion 364, and the connecting portion 343, and a magnetic path member 54 provided with the facing portion 364, the facing portion 361, and the connecting portion 344.

[0027] The magnetic path member 51 will now be described. The magnetic path member 51 has a strip shape as a whole and includes a first salient pole portion 511, a second salient pole portion 512, a yoke portion 513 connecting the first salient pole portion 511 and the second salient pole portion 512, a folded portion 514 bending downward from the end of the first salient pole portion 511, and a folded extension portion 515 folded inward from the lower end of the folded portion 514.

[0028] 4, the facing portion 36 is composed of one first salient pole portion and one second salient pole portion arranged side by side. The first salient pole portion and the second salient pole portion arranged side by side may be separated from each other, may be in contact with each other, or may be connected by welding or an adhesive.

[0029] 4, the facing portion 361 is made up of a first salient pole portion 511 and a second salient pole portion 542, the facing portion 362 is made up of a first salient pole portion 521 and a second salient pole portion 512, the facing portion 363 is made up of a first salient pole portion 531 and a second salient pole portion 522, and the facing portion 364 is made up of a first salient pole portion 541 and a second salient pole portion 532. The magnetic path member 52, 53, and 54 have the same shape as the magnetic path member 51, and therefore their description will be omitted. In addition, the connecting portion 341 is made up of a yoke portion 513, the connecting portion 342 is made up of a yoke portion 523, the connecting portion 343 is made up of a yoke portion 533, and the connecting portion 344 is made up of a yoke portion 543.

[0030] As shown in FIGS. 2 and 3 , the magnetic path members 5 of each phase intersect with each other three-dimensionally. Specifically, magnetic path member 51U has a portion that extends and overlaps the upper sides of magnetic path members 54V and 54W. Magnetic path member 51V has a portion that extends and overlaps the upper sides of magnetic path members 54W and 51U. Magnetic path member 51W has a portion that extends and overlaps the upper sides of magnetic path members 51U and 51V. Magnetic path member 52U has a portion that extends and overlaps the upper sides of magnetic path members 51V and 51W. Magnetic path member 52V has a portion that extends and overlaps the upper sides of magnetic path members 51W and 52U. Magnetic path member 52W has a portion that extends and overlaps the upper sides of magnetic path members 52U and 52V. Magnetic path member 53U has a portion that extends and overlaps the upper sides of magnetic path members 52V and 52W. The magnetic path member 53V has a portion that extends and overlaps the upper sides of the magnetic path members 52W and 53U. The magnetic path member 53W has a portion that extends and overlaps the upper sides of the magnetic path members 53U and 53V. The magnetic path member 54U has a portion that extends and overlaps the upper sides of the magnetic path members 53V and 53W. The magnetic path member 54V has a portion that extends and overlaps the upper sides of the magnetic path members 53W and 54U. The magnetic path member 54W has a portion that extends and overlaps the upper sides of the magnetic path members 54U and 54V.

[0031] The coils 8 will now be described. The coils 8 are formed by winding resin-coated copper wire around the outer periphery of the magnetic path member 5. As shown in FIG. 2, the coils 8 include four U-phase coils 8U, four V-phase coils 8V, and four W-phase coils 8W. The four coils 8 for each phase are connected in series. The coils 8U, 8V, and 8W are, for example, three-phase star-connected.

[0032] The soft magnetic wire 41 will now be described. The soft magnetic wire 41 can contain a predetermined additive element in the main component iron (Fe) in order to obtain desired magnetic properties. Examples of such additive elements include carbon (C), silicon (Si), manganese (Mn), phosphorus (P), and sulfur (S). The soft magnetic wire 41 in this example contains 0.1 mass % to 6.0 mass % silicon (Si) in the main component iron (Fe). The type and content of the additive element can be determined by experiment or simulation depending on the desired properties.

[0033] The soft magnetic wire 41 can be formed by drawing a material into a wire of the desired diameter through plastic processing such as drawing. If the outer diameter of the soft magnetic wire 41 is too large, eddy current loss increases, and if it is too small, productivity decreases. For these reasons, the outer diameter of the soft magnetic wire 41 can be set by experiment or simulation to obtain the desired characteristics. The outer diameter of the wire refers to the diameter of a circle circumscribing the cross section of the wire.

[0034] The cross-sectional shape of the soft magnetic wire 41 in the embodiment is circular, but may be elliptical. The cross-sectional shape of the soft magnetic wire 41 may be polygonal, such as triangular, rectangular, or hexagonal. The outer surface of the soft magnetic wire 41 may be insulated to reduce eddy current loss. The soft magnetic wire 41 is subjected to a predetermined heat treatment after elongation to reduce processing strain.

[0035] The operation of the rotating electric machine 100 configured as described above will now be described. When the rotating electric machine 100 is an electric motor, a three-phase drive current is supplied to each of the coils 8U, 8V, and 8W of each phase from a drive circuit (not shown). This generates a rotating magnetic field in the opposing portion 36, and the interaction between this rotating magnetic field and the magnetic poles 26 of the magnet 24 generates a rotational torque in the magnet 24. This rotational torque causes the rotor 2 to rotate together with the magnet 24.

[0036] When the rotating electric machine 100 is a generator, as the rotor 2 rotates, the positional relationship between the magnetic poles 26 and the opposing portions 36 changes sequentially. As a result, the magnitude of the magnetic flux F supplied from the magnetic poles 26 to the stator core 3 of each phase changes sinusoidally, and a three-phase AC voltage is output from the coils 8 of each phase.

[0037] The following describes the features of the axial gap type rotating electric machine 100 configured as described above. The axial gap type rotating electric machine 100 has a rotor 2 provided with a plurality of magnetic poles 26, a stator core 3 of multiple phases that axially face the magnetic poles 26, and coils 8 provided in the stator core 3, and the stator core 3 of each phase has a magnetic path member 5 that includes a plurality of opposing portions 36 that face the magnetic poles 26 and connection portions 34 that connect the opposing portions 36 together, and the connection portions 34 are connected from one of the plurality of opposing portions 36 to two opposing portions adjacent in the circumferential direction.

[0038] This configuration makes it possible to standardize the magnetic path members for each phase. As a result, magnetic path members of the same shape can be mass-produced, improving the productivity of stator cores. Furthermore, while the volume ratio of the magnetic path members to the space is low in the rotating electric machine described in Patent Document 1, in the rotating electric machine 100, the connecting portion is connected to two opposing portions, so the volume ratio is increased and magnetic resistance is smaller than in the past, allowing for effective use of the magnetic energy of the magnet. Furthermore, the small magnetic resistance also makes it possible to reduce leakage magnetic flux to the outside.

[0039] Furthermore, in the rotating electric machine 100, it is possible to uniformly arrange the multiple magnetic path members in the circumferential direction, thereby making the strength uniform overall. Furthermore, it is possible to combine multiple magnetic path members like a bamboo basket, so that each magnetic path member has a portion that is higher than the others and a portion that is lower than the others, thereby increasing the strength of the stator core.

[0040] The magnetic path member can also be made of soft magnetic wire. In particular, it is possible to form the magnetic path member by bundling multiple soft magnetic wires, which allows the cross-sectional shape of the magnetic path member to be freely changed for each section. In this case, the volume ratio of the magnetic path member to the space can be increased, reducing magnetic resistance and enabling a thinner design.

[0041] Furthermore, in the rotating electric machine 100, the magnetic path members can be constructed from electromagnetic steel sheets, and in particular, high-permeability electromagnetic steel sheets such as amorphous materials can be used. This improves the magnetic properties of the magnetic path members, which is advantageous for improving the performance and miniaturization of the rotating electric machine.

[0042] Furthermore, in the rotating electric machine 100, the stator core is formed by assembling a plurality of magnetic path members, so the stator core can be easily disassembled into the plurality of magnetic path members. This improves the maintainability of the stator core, reduces the man-hours required for disassembling and discarding the stator core, and allows some or all of the disassembled magnetic path members to be easily reused.

[0043] The above describes in detail exemplary embodiments of the present invention. The above-described embodiments merely illustrate specific examples of implementing the present invention. The content of the embodiments does not limit the technical scope of the present invention, and many design modifications, such as changes, additions, and deletions of components, are possible within the scope of the inventive concept defined in the claims. In the above-described embodiments, content that allows such design modifications is described using notations such as "in the embodiment" or "in the embodiment," but design modifications are also permissible for content not otherwise specified. Furthermore, hatching in the drawings does not limit the material of the hatched object.

[0044] [Variations] Modified examples will be described below. In the drawings and descriptions of the modified examples, the same components and members as those in this embodiment will be denoted by the same reference numerals. Explanations that overlap with this embodiment will be omitted as appropriate, and the description will focus on the configurations that differ from this embodiment.

[0045] (First Modification) The configuration of an axial gap type rotating electric machine 200 (hereinafter sometimes referred to as "rotating electric machine 200") according to a first modified example of the present invention will be described with reference to Fig. 6. Fig. 6 is a side view showing the rotating electric machine 200 according to the first modified example, and corresponds to Fig. 1. The rotating electric machine 200 of this modified example differs from the rotating electric machine 100 of the first embodiment in that the rotor 2 is provided on the opposite side of the stator core 3 across the stator support member 32, but the other configurations are similar. Therefore, the following description will focus on the differences.

[0046] 6, magnetic flux F from magnetic pole 26 passes through stator support member 32 in the axial direction, flows into one opposing portion 361, flows through connection portion 34, flows out from the other opposing portion 362, passes through stator support member 32 in the axial direction, and flows into magnetic pole 26 on the opposite side. The operation when rotating electric machine 200 is an electric motor and the operation when rotating electric machine 200 is a generator are similar to those of rotating electric machine 100.

[0047] (Other variations) In the above description, an example has been shown in which the facing portion 36 and the connecting portion 34 are configured to include the soft magnetic wire 41, but the present invention is not limited to this. For example, the facing portion 36 and the connecting portion 34 may be configured to include a magnetic steel plate (electromagnetic steel plate).

[0048] In the above description, an example has been shown in which the rotating electric machine 100 includes one rotor 2 and one stator 4, but the present invention is not limited to this. For example, the rotating electric machine may include multiple rotors, or multiple stators, or multiple rotors and multiple stators.

[0049] In the above description, the magnet 24 is an annular member surrounding the rotation axis La, but the present invention is not limited to this. For example, the magnet may be a segment magnet divided into individual drive poles. The shape of the segment magnet can be circular, elliptical, trapezoidal, sectoral, or the like.

[0050] In the above description, an example was given in which the magnet 24 was a neodymium magnet, but the present invention is not limited to this. For example, the magnet may be a rare earth magnet or a ferrite magnet whose main component is a rare earth element other than neodymium, or it may be a plastic magnet.

[0051] In the above description, the stator support member 32 is made of a non-magnetic material, but the present invention is not limited to this. For example, the stator support member may include a soft magnetic material such as an electromagnetic steel plate.

[0052] Each of these modifications provides the same functions and effects as the embodiment.

[0053] Any combination of the above-described embodiments and modifications is also useful as an embodiment of the present invention. A new embodiment resulting from the combination has the combined effects of the combined embodiments and modifications. [Explanation of symbols]

[0054] 2 rotor, 3 stator core, 4 stator, 5 magnetic path member, 8 coil, 12 shaft, 22 rotor yoke, 24 magnet, 26 magnetic pole, 34 connection portion, 36 opposing portion, 41 soft magnetic wire, 54 magnetic path member, 100 axial gap type rotating electric machine.

Claims

1. a rotor provided with a plurality of magnetic poles, a stator core of a plurality of phases axially facing the magnetic poles, and a coil provided in the stator core; the stator core of each phase has a magnetic path member including a plurality of opposing portions that face the magnetic poles and connection portions that connect the opposing portions to each other, The connecting portion is connected from one of the plurality of opposing portions to two opposing portions adjacent in the circumferential direction.

2. The axial gap type rotating electric machine according to claim 1 , wherein the opposing portion and the connecting portion are configured to include a soft magnetic wire.

3. The axial gap type rotating electric machine according to claim 1 , wherein the opposing portion and the connecting portion are configured to include magnetic steel plates.

4. The axial gap type rotating electric machine according to claim 2 , wherein the facing portion and the connecting portion are formed by bundling a plurality of soft magnetic wires.

5. 3. The axial gap type rotating electric machine according to claim 2, wherein the cross section of the soft magnetic wire is circular.

6. 3. The axial gap type rotating electric machine according to claim 2, wherein the cross section of the soft magnetic wire is triangular, rectangular or hexagonal.

7. 2. The axial gap type rotating electric machine according to claim 1, wherein the stator core for each phase is made up of a plurality of magnetic path members having the same shape.

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