Rotor

Abstract

To provide a rotor in which a permanent magnet can be fixed to a slot part of a core while suppressing stress to a magnetic steel sheet when the permanent magnet is inserted into the slot part of the core.SOLUTION: A rotor (1) is the rotor having a core (2) in which magnetic steel sheets (4) are laminated; and a permanent magnet (3) inserted into a slot part (2a) of the core (2). The rotor includes: a push-in part (41a) which protrudes from a penetration part constituting the slot part (2a) of the magnetic steel sheets (41) toward a side of the permanent magnet (3), is brought into line-contact with the permanent magnet (3) in a direction perpendicular to a lamination direction of the magnetic steel sheets (4) and pushes the permanent magnet (3) into a peripheral face of the slot part (2a); and a slit part (41b) formed in the magnetic steel sheets (41) for reducing flexure rigidity of the magnetic steel sheets (4) in the lamination direction in the push-in part (41a).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a rotor, for example, a rotor having a core formed by laminating electromagnetic steel sheets and permanent magnets inserted into slots in the core. [Background technology]

[0002] For example, the rotor of an IPM (Interior Permanent Magnet) motor or the like has a configuration in which permanent magnets are inserted into slots in a core made of laminated electromagnetic steel sheets. In this case, the rotor of Patent Document 1 has a configuration in which protruding support parts protruding from the parts of the electromagnetic steel sheets that form the slots are brought into line contact with a pair of shoulder parts of the permanent magnet in the lamination direction of the electromagnetic steel sheets, thereby fixing the permanent magnet to the core. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-72529 Summary of the Invention [Problem to be solved by the invention]

[0004] The present applicant has discovered the following problem. In the rotor of Patent Document 1, the support portions of the electromagnetic steel sheets are protruding, and therefore have high bending rigidity. When the permanent magnets are inserted into the slots of the core, the support portions come into strong contact with the permanent magnets, pulling the electromagnetic steel sheets, and sometimes creating gaps between the electromagnetic steel sheets. When gaps like this occur between the electromagnetic steel sheets, there is a problem that electromagnetic repulsion is generated by the magnetic flux, causing stress on the electromagnetic steel sheets.

[0005] The present disclosure has been made in consideration of such problems, and realizes a rotor in which permanent magnets can be fixed to the slots of the core while suppressing stress on the electromagnetic steel sheets when the permanent magnets are inserted into the slots of the core. [Means for solving the problem]

[0006] A rotor according to one aspect of the present disclosure is a rotor having a core formed by laminating electromagnetic steel sheets and permanent magnets inserted into slots of the core, a push-in portion that protrudes from a through portion that constitutes the slot portion of the electromagnetic steel sheet toward the permanent magnet, makes line contact with the permanent magnet in a direction perpendicular to the lamination direction of the electromagnetic steel sheet, and pushes the permanent magnet into the circumferential surface of the slot portion; a slit portion formed in the electromagnetic steel sheet to reduce bending rigidity in the stacking direction of the electromagnetic steel sheet at the indentation portion; Equipped with.

[0007] In the rotor described above, it is preferable that the push-in portion is inclined toward an insertion direction of the permanent magnet into the slit portion.

[0008] In the rotor described above, the push-in portions are preferably arranged at equal intervals in the lamination direction of the electromagnetic steel sheets.

[0009] In the rotor described above, it is preferable that the push-in portion is arranged so as to push the permanent magnet toward the outer periphery of the core.

[0010] The rotor described above preferably includes a rib connecting edge portions of the slit portion that face each other in a direction in which the push-in portion protrudes from the through portion. [Effects of the Invention]

[0011] According to the present disclosure, it is possible to realize a rotor in which permanent magnets can be fixed to the slots of the core while suppressing stress on the electromagnetic steel sheets when the permanent magnets are inserted into the slots of the core. [Brief explanation of the drawings]

[0012] [Figure 1] 2 is a YZ cross-sectional view showing the configuration of the periphery of a slot portion of a core in a rotor according to an embodiment. FIG. [Figure 2]2 is an XY cross-sectional view taken along the line II-II in FIG. 1; [Figure 3] FIG. 2 is an XY cross-sectional view taken along the line III-III in FIG. [Figure 4] 4 is an XY cross-sectional view illustrating the shape of a press-in portion of an electromagnetic steel sheet before a permanent magnet is inserted into a slot portion of a core in a rotor according to an embodiment. FIG. [Figure 5] 10A and 10B are XY cross-sectional views illustrating the shapes of the periphery of the press-in portions of different electromagnetic steel sheets when permanent magnets are inserted into slots in the core of the rotor. DETAILED DESCRIPTION OF THE INVENTION

[0013] Specific embodiments to which the present disclosure is applied will be described in detail below with reference to the drawings. However, the present disclosure is not limited to the following embodiments. In addition, the following description and drawings have been simplified as appropriate for clarity of explanation.

[0014] First, the configuration of the rotor of this embodiment will be described. Here, for clarity, the following description will be made using a three-dimensional (XYZ) coordinate system. Furthermore, the following description of the rotor configuration will be made on the assumption that permanent magnets are inserted into the slots of the core.

[0015] Fig. 1 is a YZ cross-sectional view showing the configuration of the periphery of a slot portion of a core in a rotor of this embodiment. Fig. 2 is an XY cross-sectional view taken along line II-II in Fig. 1. Fig. 3 is an XY cross-sectional view taken along line III-III in Fig. 1.

[0016] As shown in Figures 1 to 3, rotor 1 includes a core 2 and permanent magnets 3. Core 2 is formed by laminating electromagnetic steel sheets 4 in the Z-axis direction. Electromagnetic steel sheets 4 have a basic annular shape and include first through-holes 4a for forming slots 2a of core 2 and second through-holes (not shown) for inserting a rotating shaft into core 2.

[0017] As shown in Figures 2 and 3, the first through portion 4a has a generally rectangular shape that is long in one axis direction when viewed from the Z-axis direction. Here, the longitudinal direction of the first through portion 4a is defined as the X-axis direction. For example, multiple sets of first through portions 4a, each set consisting of two first through portions 4a arranged in a generally V-shape, are arranged at predetermined locations along the periphery of the electromagnetic steel sheet 4. The second through portion is arranged approximately in the center of the electromagnetic steel sheet 4.

[0018] Of the multiple laminated electromagnetic steel sheets 4, a predetermined electromagnetic steel sheet 41 (which may be designated by the reference numeral 41 to distinguish it from the other electromagnetic steel sheets) has a push-in portion 41a and a slit portion 41b, as shown in Figures 1 and 2. The push-in portion 41a makes approximate line contact with the permanent magnet 3 and pushes the permanent magnet 3 into the circumferential surface of the slot portion 2a of the core 2.

[0019] 1 and 2, the push-in portion 41a is a generally rectangular plate that is long in the X-axis direction when viewed from the Z-axis direction, and protrudes toward the negative Y-axis side from the first through portion 4a of the electromagnetic steel sheet 41. The push-in portion 41a is disposed, for example, at approximately the center of the first through portion 4a of the electromagnetic steel sheet 41 in the X-axis direction.

[0020] 1, the push-in portion 41a is inclined toward the negative Y-axis side as it moves toward the negative Z-axis side, which is the insertion direction in which the permanent magnet 3 is inserted into the slot portion 2a of the core 2. Here, the positive Y-axis side is the inner circumferential side of the core 2, and the negative Y-axis side is the outer circumferential side of the core 2.

[0021] 1 and 2, the negative Y-axis side end of the push-in portion 41a is in approximate line contact with the positive Y-axis side side of the permanent magnet 3 in the approximate X-axis direction, and the restoring force of the push-in portion 41a, which acts clockwise when viewed from the positive X-axis side, pushes the permanent magnet 3 into the negative Y-axis side circumferential surface of the slot portion 2a of the core 2. At this time, when the rotor 1 rotates, a centrifugal force is generated on the negative Y-axis side, but the push-in portion 41a is positioned on the positive Y-axis side relative to the permanent magnet 3.

[0022] The slit portion 41b is formed in the electromagnetic steel sheet 41 to reduce the bending rigidity of the push-in portion 41a in the Z-axis direction. For example, as shown in Fig. 2, the slit portion 41b is formed around the connection portion of the push-in portion 41a with the first through portion 4a, and is a substantially rectangular through portion when viewed from the Z-axis direction.

[0023] As shown in Fig. 1, the electromagnetic steel sheets 4, 41 are stacked such that the first through-holes 4a and the second through-holes overlap when viewed from the Z-axis direction to form the core 2. Therefore, the core 2 has slots 2a formed by the first through-holes 4a of the stacked electromagnetic steel sheets 4, 41. The core 2 also has insertion portions formed by the second through-holes of the stacked electromagnetic steel sheets 4, 41, into which a rotating shaft is inserted. The rotating shaft is inserted and fixed in the insertion portion of the core 2.

[0024] In this case, it is preferable that the electromagnetic steel sheets 41 are arranged at least on the Z-axis positive side and the Z-axis negative side of the core 2. Furthermore, it is preferable that the electromagnetic steel sheets 41 are arranged at approximately equal intervals in the Z-axis direction.

[0025] 1 and 2, the permanent magnet 3 is inserted into the slot portion 2a of the core 2. As shown in, for example, FIGS. 2 and 3, the permanent magnet 3 is a substantially rectangular column that is long in the X-axis direction when viewed from the Z-axis direction, and is covered with an insulating coating.

[0026] Next, a process for inserting permanent magnets 3 into slots 2a of core 2 in rotor 1 of this embodiment will be described. Fig. 4 is an XY cross-sectional view illustrating the shape of the press-in portion of the electromagnetic steel sheet before the permanent magnets are inserted into the slots of the core in the rotor of this embodiment, and corresponds to Fig. 2.

[0027] 4, the push-in portions 41a of the electromagnetic steel sheet 41 before the permanent magnets 3 are inserted into the slots 2a of the core 2 are arranged substantially parallel to the XY plane. Therefore, the push-in portions 41a and the slit portions 41b can be formed together with the first through portions 4a and the like when the electromagnetic steel sheet 41 is press-formed.

[0028] The permanent magnet 3 is inserted from the Z-axis positive side toward the Z-axis negative side into the slot portion 2a of the core 2 configured using such electromagnetic steel sheets 4, 41. As a result, as shown in Figures 1 and 2, as the permanent magnet 3 is inserted into the slot portion 2a of the core 2, the Y-axis negative side end of the push-in portion 41a of the electromagnetic steel sheet 41 is pushed into the permanent magnet 3 and comes into approximate line contact with the Y-axis negative side peripheral surface of the permanent magnet 3 in approximately the X-axis direction while rotating counterclockwise as viewed from the X-axis positive side.

[0029] As a result, the restoring force of the push-in portion 41a of the electromagnetic steel sheet 41 pushes the permanent magnet 3 into the circumferential surface on the negative Y-axis side of the slot portion 2a of the core 2, fixing the permanent magnet 3 to the core 2. At this time, the push-in portion 41a of the electromagnetic steel sheet 41 makes approximate line contact with the permanent magnet 3 in the approximate X-axis direction, so the stress acting on the insulating coating of the permanent magnet 3 is smaller than when the push-in portion 41a makes point contact with the permanent magnet 3. Therefore, damage to the insulating coating of the permanent magnet 3 can be suppressed.

[0030] Moreover, because the electromagnetic steel sheet 41 has the slits 41b, the bending rigidity of the push-in portions 41a in the Z-axis direction can be reduced compared to when the electromagnetic steel sheet 41 does not have the slits 41b, which allows the push-in portions 41a of the electromagnetic steel sheet 41 to be deformed favorably as the permanent magnet 3 is inserted.

[0031] Therefore, as the permanent magnet 3 is inserted into the slot 2a of the core 2, the electromagnetic steel sheet 41 can be prevented from being pulled toward the negative Z-axis side via the push-in portion 41a, and gaps in the Z-axis direction are less likely to occur between the electromagnetic steel sheets 4, 41. As a result, electromagnetic repulsion due to magnetic flux is less likely to occur in the electromagnetic steel sheets 4, 41, and stress on the electromagnetic steel sheets 4, 41 can be reduced.

[0032] In this way, rotor 1 of this embodiment can suppress stress on electromagnetic steel sheets 4, 41, and can also secure permanent magnets 3 to slots 2a of core 2 well by means of pressed-in portions 41a of electromagnetic steel sheets 41.

[0033] Moreover, in rotor 1 of this embodiment, when electromagnetic steel plates 41 are arranged at approximately equal intervals in the Z-axis direction, permanent magnets 3 can be pressed into the circumferential surfaces of slot portions 2a of core 2 without bias.

[0034] If the pressed-in portion 41a of the electromagnetic steel sheet 41 is positioned on the negative side of the Y axis relative to the permanent magnet 3, centrifugal force is generated in the permanent magnet 3 as the rotor 1 rotates, and the pressed-in portion 41a of the electromagnetic steel sheet 41 is repeatedly pressed strongly and weakly into the permanent magnet 3, which may cause deterioration of the pressed-in portion 41a of the electromagnetic steel sheet 41.

[0035] On the other hand, in the rotor 1 of this embodiment, when the pressed-in portion 41a of the electromagnetic steel plate 41 is positioned on the + side of the Y axis relative to the permanent magnet 3, even if the rotor 1 rotates and centrifugal force is generated in the permanent magnet 3, the pressed-in portion 41a of the electromagnetic steel plate 41 is less likely to be affected by the centrifugal force, and deterioration of the pressed-in portion 41a of the electromagnetic steel plate 41 can be suppressed.

[0036] The present disclosure is not limited to the above-described embodiments, and can be modified as appropriate within the scope of the present disclosure.

[0037] For example, the electromagnetic steel sheet 41 may have ribs 41c that connect the periphery of the slit portion 41b on the positive side of the Y axis with the periphery on the negative side of the Y axis, as shown in Fig. 5. The ribs 41c may be disposed approximately in the center of the slit portion 41b in the X axis direction, or may be disposed at approximately equal intervals in the X axis direction. This makes it possible to level the pressure distribution on the permanent magnet 3 when the permanent magnet 3 is pressed by the pressing portion 41a of the electromagnetic steel sheet 41. Therefore, damage to the insulating coating of the permanent magnet 3 can be further suppressed.

[0038] For example, the arrangement and shape of the slots 2a of the core 2 are merely examples and can be changed as appropriate.

[0039] For example, the push-in portion 41a of the electromagnetic steel sheet 41 protrudes from the first through portion 4a of the electromagnetic steel sheet 41 toward the negative Y-axis side, but it is sufficient that it is arranged so as to be able to make approximate line contact with the permanent magnet 3 in a direction perpendicular to the stacking direction of the electromagnetic steel sheet 41. Furthermore, the shape of the push-in portion 41a of the electromagnetic steel sheet 41 is an example, and it is sufficient that it has a shape that allows it to make approximate line contact with the permanent magnet 3.

[0040] For example, the shape and arrangement of the slit portions 41b of the electromagnetic steel sheet 41 are merely examples, and any shape and arrangement that can reduce the bending rigidity of the push-in portions 41a of the electromagnetic steel sheet 41 in the Z-axis direction may be used. [Explanation of symbols]

[0041] 1 rotor 2 cores, 2a slot 3. Permanent magnets 4, 41 Electrical steel sheet 4a First penetration 41a Push-in part 41b Slit section 41c Rib

Claims

1. A rotor having a core made of laminated electromagnetic steel sheets and permanent magnets inserted into slots in the core, a push-in portion that protrudes from a through portion that constitutes the slot portion of the electromagnetic steel sheet toward the permanent magnet, makes line contact with the permanent magnet in a direction perpendicular to the lamination direction of the electromagnetic steel sheet, and pushes the permanent magnet into the circumferential surface of the slot portion; a slit portion formed in the electromagnetic steel sheet to reduce bending rigidity in the stacking direction of the electromagnetic steel sheet at the indentation portion; A rotor comprising:

2. The rotor according to claim 1 , wherein the push-in portion is inclined in a direction in which the permanent magnet is inserted into the slit portion.

3. The rotor according to claim 1 or 2, wherein the indentations are arranged at equal intervals in a lamination direction of the electromagnetic steel sheets.

4. The rotor according to claim 1 or 2, wherein the push-in portion is arranged to push the permanent magnet toward the outer periphery of the core.

5. The rotor according to claim 1 or 2, wherein the push-in portion of the slit portion includes a rib connecting edges that face each other in a direction protruding from the through-hole.

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