JPWO2014162354A1 - Stator core of rotating electrical machine and method for manufacturing the same - Google Patents

Abstract

In a stator core of a rotating electrical machine in which a plurality of substantially hollow disk-shaped iron cores 5 are stacked and fixed to form a substantially hollow cylindrical shape, 90 °, 90 °, 60 ° on the circular outer periphery of each core core 5 A plurality of straight cutouts 2 are provided at unequal pitches at intervals of 60 ° and 60 °, further, stator slots 6 are provided at regular intervals, and each core punching plate 5 is placed between the straight cutouts 2 one by one. The angles are equivalent to common divisors of 90 ° and 60 °, and the layers are rotated by an angle that is a multiple of the interval between the stator slots 6.

Description

  The present invention relates to a stator core of a rotating electrical machine and a method for manufacturing the same.

  A stator iron core of a rotating electrical machine is generally formed by punching a strip-shaped electrical steel sheet having a thickness of 0.35 to 0.6 mm in a required shape and laminating them. Although the magnetic flux flows through the iron core, the outer diameter of the iron core is ideally circular so that the cross-sectional area is uniform (the magnetic flux density is constant). However, when a large amount of iron core punch is used, in order to increase productivity, punching from the strip-shaped electrical steel sheet may be arranged in two rows in a grid and performed simultaneously. At this time, in order to reduce the amount of electromagnetic steel sheet used, four straight notches are provided at an equal pitch of 90 ° so that the distance between the centers of adjacent iron cores is slightly closer than the diameter of the iron cores. It was. This straight notch is not necessary for manufacturing and is provided in consideration of the material cost. However, the magnetic flux density is increased at the location where the straight notch is present, which causes deterioration of characteristics. In the conventional rotating electrical machine, on the premise that the linear notches are arranged at an equal pitch, by rotating and rotating the core punched plate at an angle obtained by dividing 360 ° by an integer larger than the number of the linear notches, The linear notches were evenly distributed on the circumference of the stator core to make the magnetic flux density uniform (see Patent Document 1).

JP-A-5-168178 (4th page, FIG. 2)

  However, when further improving the yield, straight cutouts may occur at unequal pitches. In this case, the angle is obtained by dividing 360 ° by an integer larger than the number of straight notches as in the prior art, and when the iron core punches are rotated and stacked at this angle, the straight notches are placed on the circumference of the stator core. There is a problem that the magnetic flux density is not evenly distributed.

  The present invention has been made to solve the above-described problems, and even when the linear cutouts arranged on the core punching plate are arranged at unequal pitches, the magnetic flux density of the stator core is made uniform. It is to obtain a stator core of a rotating electrical machine that can prevent deterioration of product performance.

  In the stator iron core according to the present invention, the cutout plates are provided with linear notches at unequal pitches, and the cutout plates are laminated while being rotated in the circumferential direction by an angle that is a common divisor of the unequal pitches.

  The present invention provides a circumferential notch on the stator core by providing straight notches on the punched plate at unequal pitches, and laminating the punched plates while rotating them in the circumferential direction at an angle that is a common divisor of the unequal pitch. The straight cutouts are evenly distributed, the magnetic flux density is made uniform, and the characteristics can be improved.

It is a figure which shows the material removal of the core punching board of the stator core of the rotary electric machine in Embodiment 1 of this invention. It is a perspective view which shows the stacking direction of the iron core punch of the stator core of the rotary electric machine in Embodiment 1 of this invention. It is the figure which divided the core extraction board of the stator core of the rotary electric machine in Embodiment 1 of this invention into 12 parts. It is a figure which shows the material removal of the rotary electric machine in the iron core punch of the conventional stator iron core.

Embodiment 1 FIG.
FIG. 1 is a view showing material removal of a core punched plate 1 of a stator core of a rotating electric machine. The iron core punching plate 1 is punched from a strip-shaped electromagnetic steel sheet 3 having a rectangular shape and a thickness of about 0.35 to 0.6 mm. The remainder obtained by punching the iron core punch 1 from the strip-shaped electromagnetic steel sheet 3 is a discarded portion 4. Half-pitch (half the distance between the centers of adjacent core punches) to take the material in two rows on the left and right along the longitudinal direction of the strip-shaped electrical steel sheet 3 Shift. That is, in the right column of the strip-shaped electrical steel sheet 3, for example, in the core punched plate 1A, one side in the longitudinal direction of the strip-shaped electrical steel plate 3 at a 90 ° clockwise position from the point of contact A with the adjacent iron core strip on the upper side. And 4 to 90 °, 60 °, 60 ° and 60 °, respectively, and the adjacent core punched plate 1 is contacted. In the left column of the strip-shaped electrical steel sheet 3, for example, in the core core 1 </ b> B, a portion 90 ° counterclockwise from the point B of contact with the upper adjacent core core is located in the longitudinal direction of the strip-shaped electrical steel sheet 3. One position is in contact with one side, and four positions of 90 °, 60 °, 60 °, and 60 ° are in contact with the adjacent iron core punch 1 from there. Further, in order to reduce the area of the discarded portion 4, it is necessary to make the distance between the centers of the adjacent core punched plates 1 smaller than the diameter of the core punched plate 1, Or the boundary which touches the adjacent iron core punching board 1 is provided with the straight line instead of the point. This straight line portion is referred to as a straight cutout 2 here. That is, the iron core punch 1 is 90 °, 90 °, 60 °, 60 ° at a total of five locations, ie, the border between the side of the strip-shaped electromagnetic steel plate 3 and the four core borders with respect to the circular shape. The shape is such that the straight notches 2 are provided at unequal pitches of 60 ° and 60 °.

  FIG. 2 is a perspective view showing the stacking direction of the iron core punching plates 1. Prior to punching the iron core punched plate 1 from the strip-shaped electromagnetic steel plate 3 as shown in FIG. The stator core 5 is configured by stacking the core cores 1, and the number of the core cores 1 for one rotating machine exceeds 100. The core punch 1 is laminated in a state rotated by 30 °. As a result, when viewed as a whole of the stator core 5, the influence of the straight notch 2 is distributed at equal intervals with respect to the outer periphery of the core punch 1; The cross-sectional area through which the magnetic flux flows becomes nearly uniform, and the magnetic flux density does not increase locally. The means for fixing the laminated core punched plates 1 is, for example, welding.

  The structure in which the iron core punches in FIG. 3 are stacked by being rotated by 30 ° will be described in detail below. FIG. 3 is a diagram in which the iron core punch 1 is divided into 12 portions each including a straight cutout 2 and a portion not including the straight cutout 2 by 30 ° in the circumferential direction. In the hollow disk-shaped iron core blank 1, 36 stator slots 6 omitted in FIG. 2 are provided at equal intervals outside the hollow circle. The stator slot 6 is for inserting a stator winding (not shown) after laminating the core cores 1. In FIG. 3, all the center angles of 30 ° of the fan-shaped arc having a center angle of 30 ° are illustrated as straight notches 2, but the centers of the iron cores 1 disposed in the belt-shaped electromagnetic steel plate 3 are illustrated. Depending on the distance, a part of the fan-shaped arc may be a straight notch 2. In FIG. 3, the symbols A, a, b, B, c, d, C,. Here, capital letters A, B,... E indicate areas where the straight cutout 2 exists, and small letters a, b, c,. Next, Table 1 below shows the dispersion state of the straight notches 2 when the core punched plates 1 are stacked while being rotated by 30 °.

  The vertical column indicates the first to thirteenth layers, and the horizontal row indicates an area obtained by dividing the circle into twelve. 3 is arranged in this direction in the first layer, the second layer is obtained by rotating the iron core in FIG. 3 by 30 ° counterclockwise, and the third layer is A second layer core punched plate rotated 30 ° counterclockwise is laminated. The horizontal column of Table 1 shows a region obtained by dividing 360 ° into 12 parts. For example, the region 1 indicates a region in the 12 o'clock direction, and the region 2 indicates a region in the 11 o'clock direction in the region 30 ° adjacent to the region 1 counterclockwise. For example, in the first layer, a straight cutout of A is arranged in the area 1 in the 12 o'clock direction, an arc of a is arranged in the area 2 in the 11 o'clock direction, and a circular arc of g is arranged in the area 12 in the 1 o'clock direction. The The second layer rotates the core punching plate of FIG. 3 by 30 ° counterclockwise, so that a circular arc of g is present in the region 1 in the 12 o'clock direction, a straight notch of A in the region 2 in the 11 o'clock direction, In the region 12 in the 1 o'clock direction, an E straight cutout is arranged.

Since the core punching plate is rotated by 30 °, the 13th layer has the same pattern as the 1st layer. Therefore, the pattern in which the straight cutout 2 appears is repeated every 12 layers. When stacked in this manner, in each of the regions 1 to 12, (1) straight cutout, (2) circular arc, (3) straight cutout, (4) circular arc, (5) straight cutout, (6) It is laminated with a 12-layer cycle of arc, (7) straight notch, (8) arc, (9) arc, (10) straight notch, (11) arc, and (12) arc. In this one pattern (for 1 to 12 layers), the number of straight cutouts and the number of arcs are 5 and 7 respectively in all regions 1 to 12. In other words, by periodically laminating in this way, the stator core of the rotating machine becomes almost cylindrical in shape even though the core core 1 is not a perfect circle, so that the magnetic flux density can be made constant. The method of laminating the iron cores may be an adhesive iron core or the like. Furthermore, as described above, since the number of core punches for one rotating electrical machine is almost over 100, the number of core punches for one rotating electrical machine does not necessarily need to be a multiple of twelve. The effect of the present invention can be obtained even if the number is off.

Note that the rotation direction of the stack may be either clockwise or counterclockwise as long as the direction is unified in all layers. In the present embodiment, the straight notches 2 of the iron core punching plate 1 are provided at unequal pitches, and the angles between the straight notches 2 are 90 °, 90 °, 60 °, 60 °, 60 °, and the iron core punching is performed. Although the rotation angle when the plates 1 are rotated and stacked is 30 °, the rotation angle may be a common divisor of 90 ° and 60 °, and is not limited to these values. For example, the angle can be 10 °. In this case, one pattern consists of 36 layers. Further, if the rotation angle of the stack is a multiple of the interval between the stator slots, the stator winding can be inserted without any problem. However, even when the rotation angle of the stack is not a multiple of the interval between the stator slots, the stator slots may be provided so as to penetrate the core punched plate after stacking.

Next, the depth of the straight cutout 2 will be described in detail. As shown in FIG. 3, the depth k of the straight notch 2 is expressed by the following equation using the radius D1 of the portion where the straight notch 2 is not present and the radius D2 of the core punched plate where the straight notch is present. expressed.
k = D1-D2 (1)
When the straight cutout of the iron core punching plate 1 is too large, there is a portion where no arc appears at 30 ° rotation. Therefore, it is desirable that the depth of the straight notch be the following formula (2).
k <D1 * (1-COS15 °) (2)
Expression (2) is derived from the condition that the angle formed by the two line segments connecting the end portions of the straight cutout 2 and the center of the core punching plate 1 is less than 30 °. That is, the case where all the fan-shaped arcs having a central angle of 30 ° become the straight cutout 2 means that the length of the straight cutout 2 is the upper limit. By setting the depth of the straight notch 2 as described above, even if the stack is rotated by 30 °, an arc portion always appears, so that the magnetic flux density can be made constant. In this embodiment, the rotation angle is set to 30 °, but is not limited to this value. Assuming that the rotation angle of the iron core punching plate 1 is θ, the depth k of the straight cutout may satisfy the following formula (3).
k <D1 * (1-COS (θ / 2)) (3)

Next, the effect when the iron core blank 1 is provided with the linear notches 2 of unequal pitch will be described. FIG. 4 is a view showing material removal of a rotating electric machine in a conventional core punching of a stator core. As for the conventional iron core punching board 1, the linear notch 2 is provided in four places every 90 degrees. In addition, the same symbol is attached | subjected about the location showing the same part as FIG. In this material removal, when the diameter of the core punching plate 1 is D1, the area A1 of the strip-shaped electromagnetic steel sheet 3 necessary for punching one iron core punching plate 1 is expressed by the following formula (4). In addition, in order to simplify calculation, it calculated about the case where there is no straight notch and the adjacent iron core punches are in contact at points.
A1 = (2 * D1) ² = 4 · D1 ² ·· (4)
On the other hand, in the material removal according to the present invention, the area A2 of the strip-shaped electromagnetic steel sheet 3 necessary for punching one iron core punch 1 is expressed by the following formula (5). In addition, similarly to Formula (4), it calculated about the case where the adjacent iron core punches are contacting by the point.
A2 = (2 + √3) · D1 ² ≈3.73 · D1 ² ·· (5)
That is, with the material picking according to the present invention, the strip-shaped electrical steel sheet 3 can be reduced by about 7% to manufacture the stator core. In the above description, the calculation is performed on the assumption that the straight notch 2 is not present. However, even if the straight notch 2 is present, substantially the same result can be obtained.

  In the present invention, for example, in order to further improve the yield, even when the straight notches 2 are generated at unequal pitches, the magnetic flux density in the stator core can be kept uniform, and deterioration of product performance can be prevented. . Of course, for purposes other than the improvement of yield, it goes without saying that the characteristics can be improved by applying the present invention when the linear notches 2 occur at unequal pitches.

1 Iron core punch 2 Straight line notch

[0002]
When the angle is obtained by dividing 360 ° by a large integer, and the iron core is rotated and stacked at this angle, the linear notches are not evenly distributed on the circumference of the stator core, and the magnetic flux density is not uniform. There's a problem.
[0005]
The present invention has been made to solve the above-described problems, and even when the linear cutouts arranged on the core punching plate are arranged at unequal pitches, the magnetic flux density of the stator core is made uniform. It is to obtain a stator core of a rotating electrical machine that can prevent deterioration of product performance.
Means for Solving the Problems [0006]
In the stator core according to the present invention, a plurality of straight cutouts are provided at unequal pitches on the circular outer periphery of each core punched plate, and the common divisor of the angle between the straight cutouts for each core punched plate. The angle formed by the two line segments connecting each end of each straight notch and the center of the core punched plate is rotated when stacking the core punched plates. The angle is set below.
Effects of the Invention [0007]
The present invention provides a circumferential notch on the stator core by providing straight notches on the punched plate at unequal pitches, and laminating the punched plates while rotating them in the circumferential direction at an angle that is a common divisor of the unequal pitch. The straight cutouts are evenly distributed, the magnetic flux density is made uniform, and the characteristics can be improved.
BRIEF DESCRIPTION OF THE DRAWINGS [0008]
FIG. 1 is a diagram showing material removal of a core punched plate of a stator core of a rotating electric machine according to Embodiment 1 of the present invention.
FIG. 2 is a perspective view showing the stacking direction of the core punches of the stator core of the rotating electric machine according to Embodiment 1 of the present invention.
FIG. 3 is a view showing a core punched plate of a stator core of a rotating electric machine according to Embodiment 1 of the present invention divided into 12 parts.
FIG. 4 is a diagram showing material removal of a rotating electric machine in a conventional core punching of a stator core.
MODE FOR CARRYING OUT THE INVENTION [0009]
Embodiment 1 FIG.

In the stator core according to the present invention, the cutout plates are provided with straight cutouts at unequal pitches, and the cutout plates are stacked while being rotated by the angle that is a common divisor of the unequal pitches in the circumferential direction. The angle formed by the two line segments connecting each end of the notch and the center of the core core is less than the angle rotated when the core core is stacked, and the depth of each straight notch Is k, and the length of the radius of each iron core punch without a straight cut is D1, the depth of each straight cut satisfies the relationship k <D1 * (1−COS15 °). Is.

Claims (5)

In a stator core of a rotating electric machine having a substantially hollow cylindrical shape, a plurality of substantially hollow disk-shaped core punches are laminated and fixed,
A plurality of straight cutouts are provided at unequal pitches on the circular outer periphery of each iron core punch,
A stator core for a rotating electrical machine, wherein each of the core punched plates is laminated by being rotated by an angle corresponding to a common divisor of the angles between the linear notches one by one. Each iron core punch is provided with equally spaced stator slots;
2. The stator core of the rotating electrical machine according to claim 1, wherein an angle at which the iron core punch is rotated is a multiple of an interval between the stator slots. The angles formed by the two line segments that connect the both ends of each straight notch and the center of the core core are all equal to or less than the angle that is rotated when the core cores are stacked. A stator core for a rotating electrical machine according to claim 1 or 2. Five straight cutouts are provided on the circular outer periphery of the core punched plate at intervals of 90 °, 90 °, 60 °, 60 °, 60 °,
The stator core of a rotating electrical machine according to claim 1, wherein each core punching plate is laminated by rotating by an angle of a common divisor of 90 ° and 60 °. Half of the distance between the centers of the iron core punches adjacent to each other in the longitudinal direction of the electromagnetic steel sheet is shifted in the longitudinal direction in left and right rows orthogonal to the longitudinal direction, the iron core punches are arranged in a staggered manner, and the iron core punches A process of removing the material,
A step of punching the core punched plate into a hollow circle,
A method of manufacturing a stator core of a rotating electrical machine, including the step of rotating the steel core punched from the material at an angle of a common divisor of 90 ° and 60 ° and laminating the core punched plates.

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