Split stator and rotating electric machine

Abstract

To provide a split stator that can be coupled smoothly and with a sufficient force, and a rotary electric machine including the same.SOLUTION: A split stator includes a plurality of first stator pieces and a plurality of second stator pieces arranged to align in a circumferential direction of a yoke. The first stator pieces each include a first yoke constituting portion constituting the yoke and a tooth constituting portion constituting a tooth. The second stator pieces each include a second yoke constituting portion constituting the yoke. The first yoke constituting portion is sandwiched between a pair of second yoke constituting portions in the circumferential direction of the yoke. The first yoke constituting portion and the second yoke constituting portion are connected with a pair of connection surfaces opposite to each other in the circumferential direction. The pair of connection surfaces each include a surface inclined from the radial direction to one side of the circumferential direction and a surface inclined from the radial direction to the other side of the circumferential direction.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a split stator and a rotating electric machine including the split stator. [Background technology]

[0002] 2. Description of the Related Art Split stators having a configuration in which a yoke and teeth are separated are often used as stators for rotating electrical machines such as electric motors and generators.

[0003] For example, in the stator of an electric motor disclosed in Patent Document 1, a cylindrical yoke is divided into a plurality of yoke pieces in the circumferential direction, and tooth pieces are fitted into the inner surface of each yoke piece (the inner surface in the radial direction of the yoke).

[0004] In the split-type stator described above, the coil can be wound around the tooth pieces before the tooth pieces are fixed to the yoke pieces, which makes the coil winding process easier and improves the winding density. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 7-67272 Summary of the Invention [Problem to be solved by the invention]

[0006] In a rotating electric machine using a split stator such as the one described above, the yoke pieces and the tooth pieces must be joined with sufficient force to stabilize the output of the rotating electric machine. For example, when the tooth pieces are fitted into recesses provided on the inner surface of the yoke pieces, as in the stator disclosed in Patent Document 1, the dimensions of the recesses must be set appropriately and the yoke pieces and the tooth pieces must be joined with sufficient force.

[0007] However, in reality, it is not easy to form the recesses in the yoke pieces with high precision, and it is not easy to properly connect the yoke pieces and the tooth pieces. For example, if the dimensions of the recesses in the yoke pieces are too large, the yoke pieces and the tooth pieces cannot be connected with sufficient force. On the other hand, if the dimensions of the recesses in the yoke pieces are too small, the yoke pieces and the tooth pieces cannot be smoothly connected.

[0008] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a split stator that can be coupled smoothly and with sufficient force, and a rotating electric machine including the split stator. [Means for solving the problem]

[0009] The present invention relates to the following split stator and rotating electric machine.

[0010] (1) A split-type stator having a cylindrical yoke and a plurality of teeth protruding inward in a radial direction of the yoke from the yoke, a plurality of first stator pieces and a plurality of second stator pieces arranged in a circumferential direction of the yoke; each of the plurality of first stator pieces includes a first yoke component that configures the yoke and a teeth component that configures the teeth; each of the plurality of second stator pieces includes a second yoke component that constitutes the yoke; the first yoke component is sandwiched between the pair of second yoke component parts in the circumferential direction, the first yoke component and the second yoke component are connected by a pair of connecting surfaces that face each other in the circumferential direction, a split stator, wherein each of the pair of connection surfaces includes a surface inclined from the radial direction to one side in the circumferential direction and a surface inclined from the radial direction to the other side in the circumferential direction.

[0011] (2) The split stator according to (1) above, wherein the outer end of the first stator piece is located more inward than the outer end of the second stator piece in the radial direction.

[0012] (3) A split stator described in (1) or (2) above, wherein the plurality of first stator pieces and the plurality of second stator pieces are arranged so that the first stator pieces and the second stator pieces are arranged alternately in the circumferential direction.

[0013] (4) The split stator according to any one of (1) to (3) above, wherein the minimum width of the first yoke component in the circumferential direction is smaller than the minimum width of the teeth component.

[0014] (5) When viewed from the axial direction of the yoke, A split stator according to any one of (1) to (4) above, wherein the inward protrusion length of the second stator piece relative to the first yoke component in the radial direction is equal to or less than half the thickness of the second stator piece.

[0015] (6) A split stator according to any one of (1) to (5) above; a rotor disposed on the inner circumferential side of the split stator. [Effects of the Invention]

[0016] According to the present invention, it is possible to obtain a split stator that can be coupled smoothly and with sufficient force, and a rotating electric machine including the split stator. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a diagram showing the configuration of a rotating electric machine according to an embodiment of the present invention; [Figure 2] 1A and 1B are diagrams showing a split stator according to an embodiment of the present invention; [Figure 3] FIG. 2 is a diagram showing a first stator piece and a second stator piece. [Figure 4] 10A and 10B are diagrams showing other examples of the first stator piece and the second stator piece. [Figure 5] 10A and 10B are diagrams showing other examples of the first stator piece and the second stator piece. [Figure 6]10A and 10B are diagrams showing still other examples of the first stator piece and the second stator piece. DETAILED DESCRIPTION OF THE INVENTION

[0018] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A split stator according to an embodiment of the present invention and a rotating electrical machine including the split stator will be described below with reference to the drawings.

[0019] Fig. 1 is a schematic diagram showing the configuration of a rotating electric machine according to one embodiment of the present invention. As shown in Fig. 1, the rotating electric machine 100 includes a split stator 10, a rotor 20, and a case 30. Although not shown to avoid cluttering the drawing, a coil is wound around the split stator 10.

[0020] The split stator 10 has a cylindrical yoke 12 and a plurality of teeth 14 that protrude inward from the yoke 12 in the radial direction of the yoke 12. Note that the split stator 10 according to this embodiment has 12 teeth 14, but the number of teeth is not limited to 12. Details of the split stator 10 will be described later.

[0021] Rotor 20 is disposed inside split stator 10 so that its axis (center of rotation) coincides with the axis of split stator 10. Note that rotor 20 is shown in a simplified form in Fig. 1. As various known rotors can be used as rotor 20, detailed description thereof will be omitted.

[0022] The case 30 is brought into close contact with the outer peripheral surface of the yoke 12 by, for example, shrink fitting. At this time, a force is applied to the yoke 12 from the outer peripheral side by the case 30.

[0023] Fig. 2 is a diagram showing the split stator 10. As shown in Fig. 1 and Fig. 2, the split stator 10 includes a plurality of first stator pieces 16 and a plurality of second stator pieces 18 arranged side by side in the circumferential direction of the yoke 12. The first stator pieces 16 and the second stator pieces 18 can each be formed by, for example, punching out a plurality of laminated electromagnetic steel sheets.

[0024] In this embodiment, the plurality of first stator pieces 16 and the plurality of second stator pieces 18 are arranged so that the first stator pieces 16 and the second stator pieces 18 are arranged alternately in the circumferential direction of the yoke 12. In the radial direction of the yoke 12, the outer end of the first stator piece 16 is located more inward than the outer end of the second stator piece 18.

[0025] FIG. 3 is a diagram showing first stator pieces 16 and second stator pieces 18. As shown in FIG. 3, each first stator piece 16 has a first yoke component 16a that constitutes the yoke 12 and a tooth component 16b that constitutes the teeth 14. Each second stator piece 18 has a second yoke component 18a that constitutes the yoke 12. In this embodiment, the entire second stator piece 18 functions as the second yoke component 18a. In other words, in this embodiment, the second stator piece 18 does not have a tooth component that constitutes the teeth. Furthermore, in this embodiment, the yoke 12 is formed by the multiple first yoke components 16a of the multiple first stator pieces 16 and the multiple second yoke components 18a of the multiple second stator pieces 18.

[0026] The first yoke constituent portion 16a of the first stator piece 16 is sandwiched between a pair of second yoke constituent portions 18a in the circumferential direction of the yoke 12. The first yoke constituent portion 16a and the second yoke constituent portion 18a are connected by connection surfaces 40, 42 that face each other in the circumferential direction of the yoke 12. The connection surfaces 40 are surfaces formed on both sides of the first yoke constituent portion 16a in the circumferential direction of the yoke 12, and the connection surfaces 42 are surfaces formed on both sides of the second yoke constituent portion 18a in the circumferential direction of the yoke 12.

[0027] The connecting surface 40 includes surfaces 40a and 40b. The surface 40a is a surface that is inclined from the radial direction of the yoke 12 toward one side in the circumferential direction of the yoke 12, and the surface 40b is a surface that is inclined from the radial direction of the yoke 12 toward the other side in the circumferential direction of the yoke 12. The connecting surface 42 includes surfaces 42a and 42b. The surface 42a is a surface that is inclined from the radial direction of the yoke 12 toward one side in the circumferential direction of the yoke 12, and the surface 42b is a surface that is inclined from the radial direction of the yoke 12 toward the other side in the circumferential direction of the yoke 12. In this embodiment, the surface 40a and the surface 42a are in contact with each other, and the surface 40b and the surface 42b are in contact with each other.

[0028] In this specification, tilted from the radial direction of the yoke 12 to the circumferential direction of the yoke 12 refers to a state in which, when viewed from the axial direction of the yoke 12, the circumferential direction of the yoke 12 is tilted in a range of more than 0° and less than 90° with respect to the radial direction of the yoke 12.

[0029] In this embodiment, connecting surface 40 is formed so as to be recessed toward the center of first yoke component 16a in the circumferential direction of yoke 12. Therefore, in this embodiment, the minimum width of first yoke component 16a in the circumferential direction of yoke 12 is smaller than the minimum width of tooth component 16b.

[0030] (Action and effect) In the split stator 10 according to this embodiment, a plurality of first stator segments 16 and a plurality of second stator segments 18 are arranged side by side in the circumferential direction of the yoke 12. Furthermore, the first yoke constituent portion 16a of the first stator segment 16 and the second yoke constituent portion 18a of the second stator segment 18 are connected by a pair of connecting surfaces 40, 42 that face each other in the circumferential direction of the yoke 12. More specifically, the first yoke constituent portion 16a and the second yoke constituent portion 18a are connected by surfaces 40a, 42a that are inclined from the radial direction of the yoke 12 to one side in the circumferential direction of the yoke 12 contacting each other, and surfaces 40b, 42b that are inclined from the radial direction of the yoke 12 to the other side in the circumferential direction of the yoke 12 contacting each other.

[0031] In this case, the connecting surfaces 40, 42 can be brought into contact with sufficient force when the split stator 10 is shrink-fitted to the case 30, even without requiring high dimensional accuracy of the connecting surfaces 40, 42. This allows the first stator segments 16 and the second stator segments 18 to be joined with sufficient force, thereby increasing the rigidity of the split stator 10. Therefore, in the split stator 10 according to this embodiment, even if the dimensional accuracy of the first stator segments 16 and the second stator segments 18 cannot be strictly controlled, the first stator segments 16 and the second stator segments 18 can be joined smoothly with sufficient force. Note that improving the rigidity of the split stator 10 not only improves dimensional accuracy but also contributes to reducing vibration and noise during operation of the rotating electric machine 100. Furthermore, because the connecting surfaces 40, 42 have the above-described shapes, stress is generated at the connection between the first stator segments 16 and the second stator segments 18 in a direction that self-corrects any radial misalignment between them. This relatively reduces the need to apply external force to strongly fix the split stator 10 by shrink fitting or the like, and also makes it possible to reduce the amount of compressive stress generated in the split stator 10 and reduce deterioration of the characteristics of the split stator 10.

[0032] Furthermore, in the split stator 10 according to this embodiment, the outer ends of the first stator pieces 16 are located more inward than the outer ends of the second stator pieces 18 in the radial direction of the yoke 12. This prevents the first stator pieces 16 from coming into contact with the case 30 when the split stator 10 is shrink-fitted into the case 30. This prevents compressive stress from being applied from the case 30 to the first stator pieces 16 in the radial direction of the yoke 12. In other words, it prevents compressive stress from being applied from the case 30 to the teeth 14 in the radial direction of the yoke 12. As a result, the teeth 14 can be efficiently magnetized in the radial direction of the yoke 12.

[0033] Furthermore, in the split stator 10 according to this embodiment, the surfaces 40a, 40b, 42a, and 42b connecting the first stator piece 16 and the second stator piece 18 are inclined with respect to the radial direction of the yoke 12. Therefore, at the joint between the first stator piece 16 and the second stator piece 18, compressive stress is generated in a direction inclined with respect to the radial direction of the yoke 12. In other words, it is possible to prevent compressive stress from being applied from the second stator piece 18 to the first stator piece 16 in the radial direction of the yoke 12. This allows the teeth 14 to be magnetized sufficiently efficiently in the radial direction of the yoke 12.

[0034] Furthermore, in the split stator 10 according to this embodiment, the minimum width of the first yoke component 16a in the circumferential direction of the yoke 12 is smaller than the minimum width of the tooth component 16b. In this case, the length of the second yoke component 18a in the circumferential direction can be sufficiently increased at the joint between the first yoke component 16a and the second yoke component 18a. In the split stator 10 according to this embodiment, when the yoke 12 is shrink-fitted to the split stator 10, the second yoke component 18a comes into contact with the case 30. In this case, compressive stress is applied from the case 30 to the second yoke component 18a in the radial direction of the yoke 12, but an increase in compressive stress in the second yoke component 18a in the circumferential direction of the yoke 12 is suppressed. This allows the second yoke component 18a to be efficiently magnetized in the circumferential direction of the yoke 12. Therefore, by increasing the length of the second yoke component 18a that contacts the case 30 in the circumferential direction, the yoke 12 can be efficiently magnetized.

[0035] Furthermore, in the split stator 10 according to this embodiment, the plurality of first stator segments 16 and the plurality of second stator segments 18 are arranged so that the first stator segment 16 is sandwiched between a pair of second stator segments 18. In this case, the first stator segment 16 and the second stator segment 18 can each be formed to have a simple shape. Specifically, in this embodiment, the first stator segment 16 and the second stator segment 18 can each be formed to have a shape close to a rectangle. This allows the punched regions of the first stator segment 16 and the second stator segment 18 to be positioned close to each other when forming the first stator segment 16 and the second stator segment 18 by punching a laminated steel sheet, compared to when the first stator segment 16 or the second stator segment 18 is T-shaped or the like, and allows the punched regions to be positioned efficiently across the entire laminated steel sheet. As a result, the yield when forming the first stator segment 16 and the second stator segment 18 from the laminated steel sheet can be improved.

[0036] Furthermore, in this embodiment, it is possible to wind coils (not shown) around each tooth 14 at high speed before assembling the split stator 10, or to insert the teeth 14 into separately formed coils. This allows coils to be efficiently provided on the split stator 10. Furthermore, when joining the first stator piece 16 and the second stator piece 18, the teeth 14 allow the separately formed coils to be pushed into the yoke 12. This makes it easy to increase the winding density.

[0037] (Variation) In the above-described embodiment, each connecting surface 40, 42 has two inclined surfaces (surfaces inclined in the circumferential direction of the yoke 12 with respect to the radial direction of the yoke 12: surfaces 40a, 40b and surfaces 42a, 42b). However, as shown in FIG. 4, each connecting surface 40, 42 may have three or more inclined surfaces. In addition, in the above-described embodiment, each connecting surface 40, 42 is configured with a plurality of linear inclined surfaces when viewed in the axial direction of the yoke 12. However, as shown in FIG. 5, each connecting surface 40, 42 may be curved on an arc when viewed in the axial direction of the yoke 12. Although not shown, each connecting surface 40, 42 may include a surface parallel to the radial direction of the yoke 12.

[0038] Regardless of the shape of the connection surface, in order to ensure sufficient bonding strength between the first stator piece 16 and the second stator piece 18, it is preferable that the ratio of the total length of the inclined surface to the overall length of the connection surface be 0.5 or more, more preferably 0.7 or more, and even more preferably 0.9 or more.

[0039] In the above embodiment, the inner peripheral surface of the second stator piece 18 is formed in an arc shape that curves outward in the radial direction of the yoke 12. However, the shape of the second stator piece 18 is not limited to the above example. For example, as shown in FIG. 6 , the inner peripheral surface 18b of the second stator piece 18 may be formed to protrude inward in the radial direction of the yoke 12. From the viewpoint of simplifying the shape of the second stator piece 18, the inward protrusion length of the second stator piece 18 relative to the first yoke component 16a in the radial direction, as viewed from the axial direction of the yoke 12, is preferably equal to or less than half the thickness of the second stator piece 18, and more preferably equal to or less than one-quarter of the thickness of the second stator piece 18. In this specification, the inward protrusion length of the second stator piece 18 relative to the first yoke component 16a and the thickness of the second stator piece 18 are determined as follows.

[0040] 6, first, when viewed in the axial direction of the yoke 12, an imaginary circle C1 is defined that has the axis of the yoke 12 as its center and circumscribes the second stator piece 18, an imaginary circle C2 is defined that has the axis of the yoke 12 as its center and passes through the innermost position of the connecting surface 42 in the radial direction, and an imaginary circle C3 is defined that has the axis of the yoke 12 as its center and is inscribed in the second stator piece 18. The difference between the radius of the imaginary circle C1 and the radius of the imaginary circle C2 is defined as the thickness of the second stator piece 18, and the difference between the radius of the imaginary circle C2 and the radius of the imaginary circle C3 is defined as the inward protrusion length of the second stator piece 18 relative to the first yoke component 16a.

[0041] In the above-described embodiment, the first stator pieces 16 and the second stator pieces 18 are arranged alternately, but two or more second stator pieces 18 may be arranged between a pair of first stator pieces 16. In this case, the second stator pieces 18 and the second stator pieces 18 are connected by a pair of connection surfaces that face each other in the circumferential direction, similar to the connection between the first stator pieces 16 and the second stator pieces 18. Furthermore, each connection surface includes a surface that is inclined from the radial direction to one side in the circumferential direction, and a surface that is inclined from the radial direction to the other side in the circumferential direction. [Industrial Applicability]

[0042] As described above, according to the present invention, it is possible to obtain a split stator that can be coupled smoothly and with sufficient force, and a rotating electric machine including the split stator. [Explanation of symbols]

[0043] 10 split stator 12 York 14 Teeth 16 1st stator piece 16a First yoke component 16b Teeth component 18 Second stator piece 18a Second yoke component 20 rotor 30 cases 40,42 Connection surface 100 Rotating Electric Machine

Claims

1. A split-type stator having a cylindrical yoke and a plurality of teeth protruding inward in a radial direction of the yoke from the yoke, a plurality of first stator pieces and a plurality of second stator pieces arranged in a circumferential direction of the yoke; each of the plurality of first stator pieces includes a first yoke component that configures the yoke and a tooth component that configures the tooth; each of the plurality of second stator pieces includes a second yoke component that constitutes the yoke; the first yoke component is sandwiched between the pair of second yoke component parts in the circumferential direction, the first yoke component and the second yoke component are connected by a pair of connecting surfaces that face each other in the circumferential direction, each of the pair of connection surfaces includes a surface inclined from the radial direction to one side in the circumferential direction and a surface inclined from the radial direction to the other side in the circumferential direction, A split stator, wherein an outer end of the first stator piece is located more inward than an outer end of the second stator piece in the radial direction.

2. 2. The split stator according to claim 1, wherein the plurality of first stator segments and the plurality of second stator segments are provided so that the first stator segments and the second stator segments are arranged alternately in the circumferential direction.

3. 3. The split-type stator according to claim 1, wherein a minimum width of the first yoke constituent portion in the circumferential direction is smaller than a minimum width of the teeth constituent portion.

4. In the radial direction, the inner peripheral surface of the second stator piece is formed to protrude inward, When viewed from the axial direction of the yoke, 4. The split stator according to claim 1, wherein a length of inward protrusion of the second stator pieces relative to the first yoke component in the radial direction is equal to or less than half a thickness of the second stator pieces.

5. A device fitted into a cylindrical case, 5. The split stator according to claim 1, wherein, when fitted in the case, the first stator pieces are spaced apart from the case and the second stator pieces are in contact with the case.

6. The split stator according to any one of claims 1 to 5, a rotor disposed on the inner circumferential side of the split stator.

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