CN113472098B - Split core structure - Google Patents

Abstract

The invention relates to a split iron core structure, which comprises a first punching layer and a second punching layer that are stacked up and down along the axial direction, and the first punching layer is surrounded by the first fan-shaped punching and the second fan-shaped punching layer. Arranged upward, first fan-shaped punching sheets are arranged at both circumferential ends of the first punching sheet layer, and second fan-shaped punching sheets are arranged between the two first fan-shaped punching sheets located at both circumferential ends, or a second fan-shaped punching sheet is arranged. The combination of the second fan-shaped punching sheet and the first fan-shaped punching sheet, the second punching sheet layer is formed by the third fan-shaped punching sheet arranged in the circumferential direction, the second punching sheet layer is aligned with the first punching sheet layer in the axial direction, and the second punching sheet layer is arranged in the circumferential direction. The gaps between the fan-shaped punching sheets in the first punching sheet layer are staggered from the gaps between the fan-shaped punching sheets in the second punching sheet layer in the axial direction. By using two or three kinds of fan-shaped stampings, with special arrangement, a split core structure suitable for distributed winding can be constructed.

Description

Split core structure

technical field

The present invention relates to the technical field of wind power, and more particularly, to a split iron core structure, a stator iron core including the split iron core structure, and a wind power generator set including the stator iron core.

Background technique

At present, the wind power market has entered the bidding era, and the need to reduce the whole life cycle cost (ie, LCoE) of units is increasingly prominent. The enlargement of the unit is the most effective means to meet this demand. The larger the power of the unit, the larger the outer diameter of the generator of the direct-drive wind turbine, but as the outer diameter and weight of the motor slowly begin to exceed the road transportation limit (such as 4.6m, 85t), the transportation cost increases sharply. Bringing great challenges to land transportation. It is an effective technical solution to transport the motor to the project site separately, and then assemble and install it on the project site.

To split a large motor, it is necessary to split the stator core at the same time. Using a split motor with concentrated windings, splitting the iron core is easy to achieve. Although the use of concentrated winding can reduce the use of copper in the winding, and it is easy to make modularization, there are also some disadvantages, such as large harmonics generated by the concentrated winding and high stray loss of the motor. For example, for concentrated windings and split cores, if the core punches are well layered, that is, the two adjacent core punches in the axial direction are not stacked in dislocation, the circumferential sides of each core punch There is a fixed gap, which aligns the gaps existing in the iron core punches of each layer in the axial direction, thereby increasing the reluctance in the magnetic circuit of the stator yoke of the entire iron core. If the core punches are stacked with misalignment, a small reluctance is introduced for the stator yoke compared to the manner without the misalignment.

Therefore, for the split core, it is desirable to use a split core structure suitable for distributed winding. However, for the traditional iron core with the same structure, if the iron core punches are stacked in different positions, then this will not be suitable for distributed winding and split iron cores, because if the iron core punches are misaligned layer, the circumferential edge of the resulting split core will be irregular in shape.

SUMMARY OF THE INVENTION

In view of the above problems existing in the prior art, the present invention aims to provide a split core structure suitable for distributed winding.

According to an aspect of the present invention, a split core structure is provided, comprising a first punching layer and a second punching layer that are stacked up and down in the axial direction, and the first punching layer is composed of a first fan-shaped punching and a second punching layer. The second fan-shaped punches are arranged in the circumferential direction, the first fan-shaped punches are arranged at both ends of the first punching layer in the circumferential direction, and the two first fan-shaped punches located at the two circumferential ends The second fan-shaped punching sheet is arranged between the sheets, or a combination of the second fan-shaped punching sheet and the first fan-shaped punching sheet is arranged, and the second punching sheet layer is arranged in the circumferential direction by the third fan-shaped punching sheet. so that the second punching layer is axially aligned with the first punching layer, and the gap between each fan-shaped punching sheet in the first punching layer is axially aligned with the second punching layer. The gaps between each fan-shaped punching sheet in the punching sheet layer are staggered.

Preferably, the indexing angle of the first fan-shaped punching piece can be B1, the indexing angle of the second fan-shaped punching piece can be B2, the indexing angle of the third fan-shaped punching piece can be B3, and the indexing angle of B1 The size can be different from that of B2 and B3.

Preferably, the yokes of the first fan-shaped punching piece, the second fan-shaped punching piece and the third fan-shaped punching piece can be provided with opening grooves, and the opening directions of the opening grooves on the same fan-shaped punching sheet can be the same.

Preferably, the opening directions of all the opening grooves of the first punching sheet layer may be inclined toward the first direction, and the opening directions of all the opening grooves of the second punching sheet layer may be inclined toward the second direction.

The opening directions of the opening grooves of the first fan-shaped punching piece and the second fan-shaped punching piece may be inclined toward the first direction, and the opening direction of the opening grooves of the third fan-shaped punching piece may be inclined toward the second direction.

Preferably, the indexing angle between the adjacent opening grooves on each fan-shaped punch may be A, wherein the indexing angle of the first fan-shaped punch may be equal to 3A, and the second fan-shaped punch and all The indexing angle of the third fan-shaped punching sheet can be equal to 2A, or the indexing angle of the first fan-shaped punching sheet can be equal to 2A, and the indexing angle of the second fan-shaped punching sheet and the third fan-shaped punching sheet can be Equal to 3A.

Preferably, the structure of the second fan-shaped punching sheet and the third fan-shaped punching sheet can be the same, and during stacking, the second fan-shaped punching sheet can be reversely placed to obtain the third fan-shaped punching sheet.

Preferably, on each fan-shaped punching piece, the distance between the opening groove near the circumferential first end of the fan-shaped punching piece and the edge of the circumferential first end can be a1, and the distance between the opening groove near the circumferential second end and the The distance of the edge of the second circumferential end may be a2, a1+a2=A.

Preferably, a1=0.5A, a2=0.5A.

Preferably, A=5 degrees, the indexing angle of the first fan-shaped punching sheet may be 15 degrees, and the indexing angle of the second fan-shaped punching sheet and the third fan-shaped punching sheet may be 10 degrees; or, A=5 degrees, the indexing angle of the first fan-shaped punching sheet can be 10 degrees, and the indexing angle of the second fan-shaped punching sheet and the third fan-shaped punching sheet can be 15 degrees.

Preferably, the first fan-shaped punch can be made by laser cutting, and the second fan-shaped punch and the third fan-shaped punch can be molded.

According to another aspect of the present invention, a stator core is provided, which is formed by splicing the above-mentioned split core structure in the circumferential direction and the axial direction.

According to another aspect of the present invention, there is provided a wind power generator comprising the above stator core.

The split-type iron core structure provided by the invention adopts two or three kinds of fan-shaped punching pieces, and through special arrangement, the split-type iron core structure suitable for distributed winding can be constructed.

By arranging special punching structures at both circumferential ends of each punching layer (ie, at the lobes of the iron core), and making the punching structures at the lobes of the axially adjacent punching layers different, the staggered punching structure is realized. The effect of lamination (that is, the gap between each punching piece is staggered between adjacent layers), and the flat and aligned end surface structure can be realized at the split lobes of the iron core.

In addition, by adopting the above-mentioned fan-shaped punching arrangement and fan-shaped punching structure, it is beneficial to simplify the punching die and reduce the manufacturing cost.

Description of drawings

FIG. 1 shows a schematic partial cross-sectional view of a motor iron core structure in the prior art;

Fig. 2 shows the schematic diagram of the fan-shaped iron core punching piece in the prior art;

Fig. 3 shows the schematic diagram of three kinds of fan-shaped punching pieces constituting the split core structure according to the first embodiment of the present invention;

4 shows a schematic structural diagram of two adjacent punching layers according to the first embodiment of the present invention;

Fig. 5 shows the schematic diagram of three kinds of fan-shaped punching pieces constituting the split core structure according to the second embodiment of the present invention;

FIG. 6 shows a schematic structural diagram of two adjacent punching layers according to the second embodiment of the present invention.

Description of reference numbers:

1-punching; 2-stator bracket; 3-fixed key; 4-opening; 10-first sector punch; 11-open slot; 20-second sector punch; 21-open slot; 30-third sector Punching; 31-opening slot; 100-first punching layer; 200-second punching layer.

Detailed ways

In order to enable those skilled in the art to better understand the technical idea of the present invention, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings, in which the same reference numerals always denote the same components.

The existing iron core punching structure of distributed winding, and the iron core structure of synchronous motor of megawatt level and above are usually shown in Figure 1 and Figure 2, and the circumference of the stator bracket 2 is usually uniformly distributed for fixing the iron core. Fixed key 3 of punch 1. The fixed key 3 generally has a dovetail-shaped cross-section. The punching piece 1 is usually a fan-shaped punching piece, and the yoke is evenly distributed with openings 4 with an indexing angle of 0.5A, wherein A represents the indexing angle between the two openings 4 with the same opening direction, and one side of these openings 4 is opened. There is a card slot matched with the dovetail section of the fixed key 3, and there is no card slot on the other side. In addition, the positions of the card slots of these openings 4 are adjacent and staggered. When the iron core is stacked, the punching pieces 1 are arranged in sequence in the circumferential direction; when the next layer is formed, the punching pieces 1 are staggered by 0.5A in the circumferential direction; There is a gap value of 2C between each layer of adjacent punching sheets in the iron core. This staggered arrangement can ensure that the gaps between the adjacent punching pieces 1 are staggered between different layers, thereby ensuring the flatness of the core stacking, and also ensuring that the stacked cores are reliably fixed in the circumferential direction. inside the fixed key 3. Wherein, the indexing angle B=2A of all punching pieces 1 .

For the iron core structure in which the iron core punching pieces are stacked in layers, although the gaps between the adjacent punching pieces 1 are staggered between different layers, if a split iron core is formed, the circumferential direction of the split iron core will The end faces at both ends (ie, where the core splits) will be irregular, so it is not suitable for a split core structure of distributed winding.

As shown in Figures 3 and 4, the present invention provides a split iron core structure suitable for a split stator of a motor. As shown in Figure 4, the stator is divided into two lobes in the circumferential direction as an example for illustration, that is, one split The one-piece core structure is a semi-ring shape with an angle of 180°. Each split core structure is formed by a plurality of punching sheets stacked in the axial direction, and each punching sheet layer includes a plurality of fan-shaped punching sheets arranged in the circumferential direction.

As shown in FIG. 4 , the split core structure may include a first punching layer 100 and a second punching layer 200 that are adjacent to each other in the axial direction. The present invention uses the adjacent first punching layer 100 and the second punching layer. The sheet layer 200 is described. When the motor stator needs to stack more punching sheet layers, the first punching sheet layer 100 and the second punching sheet layer 200 are recycled and stacked to form the required punching sheet layer structure. The present invention proposes to arrange special fan-shaped punches at both circumferential ends of the punched layer of the split core (ie, the ends of the split structure), and to make the adjacent punched layers (for example, the second punched layer) The structure of the fan-shaped punches arranged at both ends in the circumferential direction is different from the structure of the fan-shaped punches of the punching layer (for example, the first punching layer), so that the gaps in the circumferential direction between the respective fan-shaped punches are The different punching layers are staggered and arranged, and at the same time, the end faces of the two circumferential ends of each punching layer are aligned and flat, forming a split structure that does not affect the electromagnetic performance of the stator.

Specifically, in order to realize the above-mentioned stacking structure of different punching sheets, as shown in FIG. 3 and FIG. 4 , the present invention proposes that the split core structure can be formed by stacking three kinds of fan-shaped punching sheets. The first punching layer 100 can be formed by arranging the first fan-shaped punching sheet 10 and the second fan-shaped punching sheet 20 in the circumferential direction, and the first fan-shaped punching sheet 10 can be provided at both ends of the circumferential direction of the first punching sheet layer 100 . A second fan-shaped punch 20 is arranged between the two first fan-shaped punches 10 at both ends of the circumferential direction, or a combination of the second fan-shaped punch 20 and the first fan-shaped punch 10 is arranged to form a complete split iron core punch slices. The second punching layer 200 may be formed by arranging the third fan-shaped punching sheets 30 in the circumferential direction, the second punching layer 200 may be aligned with the first punching layer 100 in the axial direction, and each of the first punching layers 100 The gaps between the fan-shaped punching sheets are staggered from the gaps between the respective fan-shaped punching sheets in the second punching sheet layer 200 in the axial direction.

The indexing angle B1 of the first fan-shaped punch 10 may be different from the indexing angle B2 of the second fan-shaped punch 20 and the indexing angle B3 of the third fan-shaped punch 30 .

Specifically, the radially inner side of the yoke of each sector-shaped punching piece 10 , 20 , 30 is provided with an open slot, and the open slot is used to receive the dovetail-shaped fixing key for fixing each sector-shaped punching piece to the stator bracket. The indexing angle between the adjacent opening grooves on each fan-shaped punching piece is A, as shown in FIG. 3 . In addition, on each fan-shaped punching piece, the distance between the opening groove near the circumferential first end (as shown in the figure, the left end) of the fan-shaped punching piece and the edge of the circumferential first end is a1, and the distance near the circumferential second end (the left end) is a1. As shown in the figure, the distance between the opening groove of the right end and the edge of the second end in the circumferential direction is a2, a1+a2=A. Preferably, both a1 and a2 are 0.5A. That is to say, the distance a1 or a2 between the two edges of each fan-shaped punching piece 10, 20, 30 that do not form a complete indexing angle A, after butting with the circumferentially adjacent punching pieces of the same layer, forms a complete circumferential direction. Indexing angle A.

In order to stagger the gaps in the circumferential direction between the respective sector-shaped punching sheets during the stacking process between the two adjacent upper and lower punching sheet layers, and at the same time, the opening grooves of the respective sector-shaped punching sheets are generally aligned in the axial direction and form a card Connect the dovetail-shaped notch of the dovetail-shaped fixed key, and align the end faces of the two circumferential ends of each punching layer in the axial direction, and each fan-shaped punching piece proposed by the present invention satisfies the following conditions: The opening directions of the grooves are all in the same direction, that is, all the opening grooves of the first fan-shaped punch 10 have the same opening direction, all the opening grooves of the second fan-shaped punch 20 have the same opening direction, and all the openings of the third fan-shaped punch 30 are opened. same direction. In the embodiment shown in FIG. 3 , the opening direction of the opening groove 11 of the first fan-shaped punch 10 and the opening groove 21 of the second fan-shaped punch 20 are the same (as shown in FIG. 3 , the opening groove 11 and the opening groove 21 The opening directions of the two sectors are generally inclined clockwise), and the opening direction of the opening groove 21 of the second fan-shaped punch 20 is opposite to the opening direction of the opening groove 31 of the third fan-shaped punch 30 (as shown in FIG. 3, the opening groove 31 is generally inclined counterclockwise); of course, it is also possible to set the opening direction of the opening slot 11 and the opening slot 21 to be inclined counterclockwise, and the opening direction of the opening slot 31 to be inclined clockwise. Meanwhile, the indexing angle B1 of the first fan-shaped punch 10 is equal to 3A, the indexing angle B2 of the second fan-shaped punch 20 and the indexing angle B3 of the third fan-shaped punch 30 are equal to 2A. Of course, the above-mentioned indexing angle B of each fan-shaped punching piece is the setting of the minimum split processing structure. It is also possible to set B1 equal to 6A and B2 equal to the size of the indexing angle A of the actual motor stator iron core punching plate and processing conditions 4A and B3 are equal to the size of the fan-shaped punching pieces of the same multiple of 4A, and the combined structure of the different punching piece structures of the split iron core of the present invention can also be realized.

Using such three kinds of fan-shaped punching sheets, during stacking, as shown in FIG. 4 , the first punching sheet layer 100 of the split iron core can be combined and arranged in the circumferential direction by the first fan-shaped punching sheet 10 and the second fan-shaped punching sheet 20 . Thus, the first fan-shaped punching sheets 10 may be provided at both ends of the first punching sheet layer 100 in the circumferential direction. Between a fan-shaped punch 10, a plurality of second fan-shaped punches 20, or a combination of a plurality of second fan-shaped punches 20 and first fan-shaped punches 10 are arranged to form a complete split iron core. The second punching layer 200 can be completely formed by combining the third fan-shaped punching plates 30 in the circumferential direction, and the second punching layer 200 is aligned with the first punching layer 100 in the axial direction, that is, both punching layers are formed The same split core structure. The fan-shaped punching structure at the two ends of the split structure is different, and the opening direction of the opening slot of the punching sheet is opposite to realize the upper and lower adjacent. Misalignment of layers. Specifically, in the present invention, the indexing angle B1 = 3A of the first fan-shaped punching sheets 10 at both ends of the first punching sheet layer 100 , and the indexing angle of the third fan-shaped punching sheets 30 at both ends of the second punching sheet layer 200 The angle B3=2A, the opening direction of the opening groove of the first fan-shaped punching piece 10 is clockwise, and the opening direction of the opening groove of the third fan-shaped punching piece 30 is counterclockwise. The gaps between the respective sector-shaped punching pieces are staggered from the gaps between the respective sector-shaped punching pieces in the second punching sheet layer in the axial direction.

Specifically, as shown in FIG. 4 , taking the iron core divided into two lobes as an example, the iron core of each lobe is 180 degrees, that is, the first punching layer 100 and the second punching layer 200 are both 180 degrees, wherein, A can be set =5 degrees, B1=3A=15 degrees, B2=2A=10 degrees, B3=2A=10 degrees. In the first punching layer 100, two long first fan-shaped punching plates 10 with an indexing angle of B1=15 degrees are placed at both ends of the first punching layer 100 in the circumferential direction, and 15 centimeters are placed at the other positions. The short second sector punch 20 with an angle of B2=10 degrees, of course, the long first sector punch 10 and the short first sector punch 10 can also be placed between the two long first sector punches 10 at both ends in the circumferential direction. The combination of the second fan-shaped punching pieces 20 only needs to meet the angle requirements. In addition, in the second punching layer 200, 18 short third sector punching pieces 30 with an indexing angle of B3=10 degrees can be placed.

At the same time, it can be achieved that the opening grooves of the respective sector-shaped punches are generally aligned in the axial direction and form a dovetail-shaped notch.

In this arrangement, a small number of relatively long and long first sector punches 10 are used, and a relatively large number of relatively small short second sector punches 20 and short third sector punches 30 are used. At the time, for the long-shaped first fan-shaped punching sheet 10 used in small quantities, it can be formed by laser cutting, and for the short-shaped second fan-shaped punching sheet 20 and the short-shaped third fan-shaped punching sheet 30 used in large quantities, only two Only one punching die can realize the manufacture of the second fan-shaped punching piece 20 and the third fan-shaped punching piece 30 , so that the punching structure suitable for the split iron core can be processed by forming the two die.

In addition, optionally, since in the present invention, the opening directions of the opening grooves included in the second fan-shaped punching piece 20 and the third fan-shaped punching piece 30 are opposite, further, a mold can be set to process the second fan-shaped punching piece. When the sheet 20 and the third fan-shaped punching sheet 30 are stacked, the second fan-shaped punching sheet 20 is turned over and used so that the opening directions of the opening grooves are opposite to form the third fan-shaped punching sheet 30 . Specifically, since the second fan-shaped punching sheet 20 and the third fan-shaped punching sheet 30 are basically the same, only the opening directions of the opening grooves are different, therefore, when making the punching sheet, only one structure of the fan-shaped punching sheet can be produced, that is, For example, the third fan-shaped punch 30 is also manufactured by using the mold for manufacturing the second fan-shaped punch 20. The second fan-shaped punch 20 and the third fan-shaped punch 30 have the same structure at this time. The third fan-shaped punch 30 can be obtained by placing the fan-shaped punching sheet 20 in the reverse direction (turning it over). In this case, the split core structure can be formed by using only two kinds of fan-shaped punching pieces. For example, only the first fan-shaped punching piece 10 and the second fan-shaped punching piece 20 can be used, and the opening grooves of the two fan-shaped punching pieces are in the same direction. In the first punching layer 100, the first fan-shaped punching sheet 10 is placed at both circumferential ends of the first punching sheeting layer 100, and the second fan-shaped punching sheet 20 or the second fan-shaped punching sheet 20 and the first fan-shaped punching sheet are placed at other positions For the combination of the punching sheets 10 , in the second punching sheet layer 200 , all the second fan-shaped punching sheets 20 are placed in reverse (ie, corresponding to the structure of the third fan-shaped punching sheet 30 ). Through this arrangement, it is very beneficial to simplify the mold and reduce the manufacturing cost.

Furthermore, FIGS. 5 and 6 show a second embodiment of the present invention. In FIGS. 5 and 6 , the short first sector punch 10, the long second sector punch 20 and the long third sector punch 30 are used, and the indexing angle B1 of the first sector punch 10 is equal to 2A, The indexing angle B2 of the second fan-shaped punching sheet 20 is equal to 3A, and the indexing angle B3 of the third fan-shaped punching sheet 30 is equal to 3A. During stacking, in the first punching sheet layer 10, the first fan-shaped punching sheet 10 is still Placed at both circumferential ends of the first punch layer 10, and at the remaining positions between the circumferential ends, place the second fan punch 20 or place a combination of the second fan punch 20 and the first fan punch 10 , in the second punching layer 30, all the third fan-shaped punching 30 are still placed.

Specifically, as shown in FIG. 6 , taking the iron core divided into two lobes as an example, the iron core of each lobe is 180 degrees, that is, the first punching layer 100 and the second punching layer 200 are both 180 degrees, wherein, A can be set =5 degrees, B1=2A=10 degrees, B2=3A=15 degrees, B3=3A=15 degrees. In the first punching sheet layer 100, two short first sector punching sheets 10 with an indexing angle of B1 = 10 degrees are placed on both ends of the first punching sheet layer 100 in the circumferential direction, next to one end in the circumferential direction ( As shown in the figure, the short first sector punch 10 on the upper side) is placed, and then a short first sector punch 10 is placed, and then the long second sector punch with the indexing angle B2=15 degrees is placed in other positions. 20, for example, place 10 long second sector punches 20, of course, between the two short first sector punches 10 located at both ends of the circumferential direction, the short first sector punch 10 and the long second sector punch 10 can also be used. Other combinations of the fan-shaped punching pieces 20 can be used as long as the angle requirements are met. In addition, in the second punching layer 200, 12 long third sector punching sheets 30 with an indexing angle of B3=15 degrees can be placed.

Compared with the first embodiment, in the second embodiment, the first fan-shaped stamping piece 10 is shorter, the second fan-shaped stamping piece 20 and the third fan-shaped stamping piece 30 are longer, so a small amount of The short first fan-shaped punching piece 10, and the longer second fan-shaped punching piece 20 and the third fan-shaped punching piece 30 are used in a larger amount, so that the number of gaps in the circumferential direction between the punching pieces is less, which is very suitable for The magnetic permeability at the core yoke has little effect.

As described above, the split iron core structure provided by the present invention adopts two or three kinds of fan-shaped punching pieces, and through special arrangement, a split iron core structure suitable for distributed winding can be constructed.

The effect of staggered lamination is achieved by disposing special punching structures at both circumferential ends of each punching layer (ie, at the lobes of the iron core), and the punching structures at the lobes of adjacent punching layers are different. (That is, the gaps between the respective punching pieces are staggered between adjacent layers), and a flat and aligned end surface structure can be realized at the split lobes of the iron core.

In addition, by adopting the above-mentioned fan-shaped punching arrangement and fan-shaped punching structure, it is beneficial to simplify the punching die and reduce the manufacturing cost.

The specific embodiments of the present invention have been described in detail above. Although some embodiments have been shown and described, those skilled in the art should understand that, without departing from the principles and spirit of the present invention whose scope is defined by the claims, These embodiments can be combined, modified and perfected (eg, different technical features of the present invention can be combined to obtain new technical solutions). These combinations, modifications and improvements should also fall within the protection scope of the present invention.

Claims (12)

1. A split iron core structure comprises a first punching sheet layer and a second punching sheet layer which are vertically overlapped along an axial direction,

the first punching sheet layer (100) is formed by arranging a first segmental punching sheet (10) and a second segmental punching sheet (20) in the circumferential direction, the first segmental punching sheet (10) is arranged at the two ends of the first punching sheet layer (100) in the circumferential direction, the second segmental punching sheet (20) is arranged between the two first segmental punching sheets (10) at the two ends in the circumferential direction, or the combination of the second segmental punching sheet (20) and the first segmental punching sheet (10) is arranged,

the second punching sheet layer (200) is formed by arranging third sector punching sheets (30) in the circumferential direction, the second punching sheet layer (200) is aligned with the first punching sheet layer (100) in the axial direction, gaps among the sector punching sheets in the first punching sheet layer (100) are staggered with gaps among the sector punching sheets in the second punching sheet layer (200) in the axial direction,

the indexing angle of the first fan-shaped punching sheet (10) is B1, the indexing angle of the second fan-shaped punching sheet (20) is B2, the indexing angle of the third fan-shaped punching sheet (30) is B3, and the size of B1 is different from the sizes of B2 and B3.

2. The split type iron core structure according to claim 1, wherein open slots (11, 21, 31) are formed in yoke portions of the first segmental punching (10), the second segmental punching (20) and the third segmental punching (30), and opening directions of the open slots on the same segmental punching are the same.

3. The split core structure of claim 2, wherein the opening directions of all the open slots of the first punched sheet layer (100) are inclined toward a first direction, and the opening directions of all the open slots of the second punched sheet layer (200) are inclined toward a second direction.

4. The split core structure of claim 2, wherein the opening directions of the open slots of the first and second segmental punching sheets (10, 20) are inclined towards a first direction, and the opening direction of the open slot of the third segmental punching sheet (30) is inclined towards a second direction.

5. The split core structure of claim 2, wherein the indexing angle between adjacent open slots on each segment is A,

the indexing angle of the first fan-shaped punching sheet (10) is equal to 3A, and the indexing angles of the second fan-shaped punching sheet (20) and the third fan-shaped punching sheet (30) are equal to 2A, or

The indexing angle of the first fan-shaped punching sheet (10) is equal to 2A, and the indexing angle of the second fan-shaped punching sheet (20) and the third fan-shaped punching sheet (30) is equal to 3A.

6. The split core structure of claim 1, wherein the second segment (20) and the third segment (30) have the same structure, and the third segment (30) is obtained by reversely placing the second segment (20) during lamination.

7. The split core structure of claim 2, wherein an indexing angle between adjacent open slots on each segment punching sheet is a, a distance from an open slot close to a circumferential first end of the segment punching sheet to an edge of the circumferential first end is a1, and a distance from an open slot close to a circumferential second end to an edge of the circumferential second end is a2, a1+ a2 ═ a, on each segment punching sheet.

8. The split core structure of claim 7, wherein a 1-0.5A and a 2-0.5A.

9. The split core structure according to claim 5, wherein A is 5 degrees, the indexing angle of the first segmental punching (10) is 15 degrees, and the indexing angles of the second segmental punching (20) and the third segmental punching (30) are 10 degrees;

or A is 5 degrees, the indexing angle of the first fan-shaped punching sheet (10) is 10 degrees, and the indexing angles of the second fan-shaped punching sheet (20) and the third fan-shaped punching sheet (30) are 15 degrees.

10. The split core structure of claim 1, wherein the first segment (10) is made by laser cutting, and the second segment (20) and the third segment (30) are molded.

11. A stator core, characterized in that it is formed by splicing the split core structure of any one of claims 1 to 10 in the circumferential and axial directions.

12. A wind park according to claim 11, wherein the wind park comprises a stator core according to claim 11.

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