Stator core

Abstract

The present disclosure provides a stator core capable of suppressing the curling of metal plates during bolt fastening. [Solution] The stator core according to the present disclosure is a stator core formed by laminating a plurality of annular metal plates, the stator core comprising: a cylindrical base portion; a projection portion protruding from the outer circumferential surface of the base portion and having an insertion hole through which a bolt is inserted; a first metal plate provided on the outer circumferential surface of the projection portion and contacting the head of a bolt when the bolt is fastened; and a welded portion that fixes at least a second metal plate adjacent to the first metal plate.

Description

Technical Field

[0001] The present disclosure relates to a stator core.

Background Art

[0002] Patent Document 1 discloses a method for manufacturing a stator core composed of a laminated structure in which a plurality of metal plates are laminated. This manufacturing method includes a block lamination step of forming a plurality of blocks in which a plurality of metal plates are laminated, and a welding step of laminating the plurality of blocks and welding adjacent blocks in the lamination direction. In the welding step, welding is performed such that the length of the welded portion formed by welding along the circumferential direction of the block is longer than the length along the lamination direction of the block.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] A plurality of protruding portions protruding toward the outer periphery are formed at equal intervals in the circumferential direction on the stator core. Holes for inserting bolts are respectively formed in the plurality of protruding portions. When a bolt is inserted into the hole and tightened, the stator core is fixed to the housing.

[0005] When tightening the bolt, due to the friction from the head of the bolt, the uppermost layer of the stator core may rotate together with the bolt and the layer may be curled.

[0006] The present disclosure has been made in view of such problems, and an object thereof is to provide a stator core capable of suppressing the curling of the metal plate when the bolt is fastened.

Means for Solving the Problems

[0007] The stator core according to this disclosure is a stator core formed by laminating a plurality of annular metal plates, the stator core comprising: a cylindrical base portion; a projection protruding from the outer circumferential surface of the base portion and having an insertion hole through which a bolt is inserted; a first metal plate provided on the outer circumferential surface of the projection portion and in contact with the head of the bolt when the bolt is fastened; and a welded portion that fixes at least a second metal plate adjacent to the first metal plate.

[0008] Multiple welded portions are provided around the outer circumference of the protruding portion at predetermined intervals.

[0009] The welded portion fixes the second metal plate and the third metal plate, which is positioned on the side of the second metal plate opposite to the first metal plate.

[0010] Multiple protrusions are provided along the circumferential direction of the base portion, and the welded portion is provided on each of the multiple protrusions. [Effects of the Invention]

[0011] According to this disclosure, it is possible to provide a stator core that can suppress the curling of metal plates when bolts are fastened. [Brief explanation of the drawing]

[0012] [Figure 1] This is a perspective view of a stator core according to an embodiment. [Figure 2] This is a view of the stator core protrusion shown in Figure 1, from the y-axis direction. [Figure 3] Figure 2 is a perspective view. [Figure 4] Figures 2 and 3 show the IV-IV cross-sectional view. [Figure 5] This diagram illustrates the occurrence of curling of metal plates due to bolt fastening. [Figure 6] This diagram illustrates the occurrence of curling of metal plates due to bolt fastening. [Modes for carrying out the invention]

[0013] Embodiments of this disclosure will be described below with reference to the drawings. For clarity of explanation, the following descriptions and drawings have been omitted and simplified as appropriate. In addition, the same elements are denoted by the same reference numerals in each drawing, and redundant explanations have been omitted where necessary. The xyz Cartesian coordinates shown in the drawings are for convenience in explaining the positional relationships of the components.

[0014] The embodiment relates to a stator core used in a rotating electric machine. The motor comprises, for example, a housing, a stator core, and a rotor (none of which are shown). The substantially cylindrical housing has a housing portion for accommodating the stator core and rotatably supports the rotor. The stator core and rotor are arranged with the axis of the housing as a common axis. Hereinafter, the direction in which a straight line passing through the axis extends will be referred to as the axial direction, the direction perpendicular to said straight line will be referred to as the radial direction, and the direction around said straight line will be referred to as the circumferential direction.

[0015] Figure 1 is a perspective view of the stator core 10 according to the embodiment. Figure 2 is a view of the protruding portion 14 of the stator core 10 in Figure 1, viewed from the y-axis direction. Figure 3 is a perspective view of Figure 2. In each figure, the y-axis direction corresponds to the axial direction described above.

[0016] The stator core 10 is formed by stacking multiple annular metal plates 11 in the y-axis direction. For example, electromagnetic steel sheets such as silicon steel sheets with insulating layers on both sides are used as the metal plates 11. By stacking multiple metal plates 11, the base portion 12, teeth 13, and protrusions 14 are integrally formed, as shown in Figure 1. The multiple teeth 13 are arranged to protrude radially inward from the inner circumferential surface of the cylindrical base portion 12. Spaces are created between adjacent teeth 13.

[0017] The protruding portion 14 is provided so as to protrude radially outward from the outer peripheral surface of the base portion 12. In the example shown in FIG. 1, the stator core 10 has three protruding portions 14. The three protruding portions 14 are formed at equal intervals in the circumferential direction of the base portion 12. An insertion hole 15 is formed in each protruding portion 14. As shown in FIG. 2, a bolt 20 for fixing the stator core 10 to the housing is inserted into the insertion hole 15.

[0018] The housing is a bottomed container having a substantially cylindrical shape with the axial direction as the longitudinal direction, and one end in the axial direction is closed. A substantially cylindrical accommodating portion is formed inside the housing. A plurality of recesses corresponding to the protruding portions 14 of the stator core 10 are provided at equal intervals in the circumferential direction in the accommodating portion. The recess is a depression formed radially outward from the inner peripheral surface of the substantially cylindrical accommodating portion. The recess extends from one end (opening) to the other end (bottom) of the housing along the axial direction.

[0019] A plurality of bolt fastening structures are provided at equal intervals in the circumferential direction between the housing and the stator core 10. The bolt fastening structure includes an insertion hole 15 provided in the protruding portion 14 of the stator core 10 and a fastening hole (not shown) provided in the bottom of the housing. By rotating the bolt inserted into the insertion hole 15 in the direction of the arrow shown in FIG. 2 and fastening it to the fastening hole of the housing, the stator core 10 can be fixed to the housing.

[0020] A stator is formed by winding a coil (not shown) around each tooth 13 of the stator core 10. In the stator, a shaft is inserted through the center, and a rotor holding a plurality of permanent magnets is arranged, thereby forming a rotating electrical machine. The rotating electrical machine is mounted, for example, in an electric vehicle or a hybrid vehicle as a motor that generates a driving force, a generator that converts the rotational force of the shaft into electrical energy, or a motor generator having both functions.

[0021] Between the protrusions 14, a welding portion 16 is provided on the outer peripheral side of the base portion 12. The welding portions 16 electrically connect the respective metal plates 11. Note that the welding portion 16 may be provided on the inner peripheral side instead of the outer peripheral side of the base portion 12. Further, in the example shown in FIG. 1, the welding portions 16 are provided parallel to the axial direction (y-axis direction), but do not necessarily have to be parallel to the axial direction. Further, in the example shown in FIG. 1, two welding portions 16 are provided between the protrusions 14, respectively, but are not limited thereto. At least one welding portion 16 may be provided.

[0022] FIG. 4 is a sectional view taken along line IV-IV of FIGS. 2 and 3. In the sectional view, the side where the head 21 of the bolt 20 is disposed is the upper side, and the side where the tip of the shaft 22 screwed into the fastening hole of the housing is disposed is the lower side. For the sake of explanation, the layers are referred to as the first layer, the second layer,... in order from the uppermost layer of the plurality of metal plates 11. Further, the uppermost layer (first layer) of the plurality of metal plates 11 is referred to as the first metal plate 11a, the lower layer (second layer) of the first metal plate 11a is referred to as the second metal plate 11b, and the lower layer (third layer) of the second metal plate 11b is referred to as the third metal plate 11c.

[0023] As shown in FIG. 4, the shaft 22 of the bolt 20 is inserted into the insertion hole 15. When the bolt 20 is tightened, the head 21 of the bolt 20 contacts the first metal plate 11a of the uppermost layer.

[0024] As shown in FIGS. 3 and 4, a welding portion 30 is provided on the outer periphery of the protrusion 14. Referring to FIG. 4, the welding portion 30 fixes at least the first metal plate 11a contacted by the head 21 of the bolt 20 and the second metal plate 11b adjacent to the first metal plate 11a when the bolt 20 is tightened.

[0025] FIGS. 5 and 6 are diagrams for explaining the occurrence of warping of the metal plate 11 due to the tightening of the bolt 20. As shown in FIG. 5, when the bolt 20 rotates in a state where the head 21 of the bolt 20 contacts the first metal plate 11a, the head 21 and the first metal plate 11a rub against each other, and a frictional force FR1 is generated. Due to this frictional force FR1, as shown in FIG. 6, the first metal plate about the protrusion 14. 11a may warp.

[0026] In this embodiment, as shown in Figure 4, at least the first metal plate 11a and the second metal plate 11b are fixed together by a welded joint 30. This makes it possible to suppress curling of the first metal plate 11a. Alternatively, the welded joint 30 may also fix the second metal plate 11b and the third metal plate 11c, which is positioned on the opposite side of the second metal plate 11b from the first metal plate 11a.

[0027] In the example shown in Figure 4, the welded joint 30 fixes the metal plates 11 between the first and second layers, between the second and third layers, and between the third and fourth layers. In this way, the welded joint 30 fixes the multiple metal plates 11 at the protruding portion 14, which further prevents the metal plates 11 from curling when the bolts 20 are fastened.

[0028] Furthermore, multiple welded joints 30 may be provided around the outer circumference of the protruding portion 14 at predetermined intervals. For example, as shown in Figure 3, welded joints 30 can be provided at a first position (P1) where the protruding portion 14 and the base portion 12 are connected, a second position (P2) furthest from the base portion 12 of the protruding portion 14, and a third position (P3) between the first position (P1) and the second position (P2). Note that the position and number of welded joints 30 on the protruding portion 14 are not limited to the example in Figure 3. By providing multiple welded joints 30 around the outer circumference of the protruding portion 14 in this way, curling of the first metal plate 11a can be further suppressed.

[0029] Furthermore, the welded portion 30 may be provided on each of the multiple protrusions 14 provided along the circumferential direction of the base portion 12. That is, a welded portion 30 may be provided on each of the three protrusions 14 shown in Figure 1. This makes it possible to suppress curling of the metal plate 11 at each of the multiple protrusions 14.

[0030] Furthermore, the welding area per weld 30 and the number of welds 30 can be appropriately determined so that the metal plate 11 does not curl up when the bolts 20 are fastened.

[0031] Although the present disclosure has been described above with reference to embodiments, the present disclosure is not limited to the embodiments described above. The present disclosure is not limited to the embodiments described above and can be modified as appropriate without departing from the spirit of the work. [Explanation of Symbols]

[0032] 10 Stator Cores 11 Metal plate 12 Base part 13 Teeth 14 Protrusion 15 Through holes 16. Welded section 20 volts 21 Head 22 axes 30 Welded section

Claims

1. A stator core made up of multiple ring-shaped metal plates stacked together, The stator core is, A cylindrical base part, A protruding portion that extends from the outer circumferential surface of the base portion and has a through-hole formed through which a bolt is inserted, A welded portion that fixes at least a first metal plate, which is provided on the outer circumference of the protruding portion and which the head of the bolt contacts when the bolt is fastened, and a second metal plate adjacent to the first metal plate, A stator core equipped with the following features.

2. The aforementioned welded portions are provided in multiple locations around the outer circumference of the protruding portion at predetermined intervals. The stator core according to claim 1.

3. The welded portion fixes the second metal plate and the third metal plate, which is positioned on the side of the second metal plate opposite to the first metal plate. The stator core according to claim 1.

4. The aforementioned protrusions are provided in multiple locations along the circumferential direction of the base portion, The welded portion is provided on each of the plurality of protrusions. The stator core according to claim 1.

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