Laminate and method for manufacturing the same

Abstract

The present invention provides a laminate that facilitates the assembly of other components and the assembly of other components. [Solution] The laminate 1 is formed by stacking multiple plates 7 and comprises multiple blocks 5 stacked on each other in the stacking direction of the plates 7, a connecting portion 9 that connects the multiple plates 7 of each block 5 in the stacking direction, and an unconnected portion 11 of each block 5 where there is no connecting portion 9. In each block 5, the maximum unconnected portion 11A, which is the unconnected portion 11 with the largest circumferential dimension, extends over a range with a central angle of 90 degrees or more, the gap 5b between adjacent plates 7 in the stacking direction of each block 5 is larger than the connecting portion 9 at least at the central part 11Aa of the maximum unconnected portion 11A in the circumferential direction, and the central part 11Aa of the maximum unconnected portion 11A of adjacent blocks 5 in the stacking direction is offset in the circumferential direction.

Description

Technical Field

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[0001] The present invention relates to a laminate formed by laminating plate materials such as cores of rotating electrical machines and a method for manufacturing the same.

Background Art

[0002] As a conventional laminate, for example, there is a stator core described in Patent Document 1. In this stator core, electromagnetic steel sheets, which are a plurality of plate materials, are laminated, and the laminated electromagnetic steel sheets are integrated by welding in the lamination direction.

[0003] Such a stator core may have shape distortions such as the axial direction being inclined with respect to the lamination direction due to variations in shape caused by processing of the magnetic steel sheet and variations in the plate thickness of the material itself. In this case, for example, it may be difficult to assemble the stator core to a frame body, which is another member. Similarly, when the laminate is a rotor core, for example, it may be difficult to assemble a permanent magnet or a shaft, which are other members, to the rotor core.

[0004] Such problems can occur in general laminates formed by laminating and bonding plate materials.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The problem to be solved is that there is a risk that it may be difficult to assemble other members to the laminate or to assemble the laminate to other members.

Means for Solving the Problems

[0007] The present invention provides a core comprising: a plurality of blocks formed by laminating a plurality of plate materials and laminated together in the lamination direction of the plate materials; a connecting portion that connects the plurality of plate materials of each block in the lamination direction; and an unconnected portion of each block without the connecting portion, wherein in each block, the maximum unconnected portion, which is the unconnected portion with the largest circumferential dimension, extends over a range of a central angle of 90 degrees or more; the gap between adjacent plate materials in the lamination direction of each block is larger than the connecting portion at least at the circumferential center of the maximum unconnected portion; and adjacent blocks in the lamination direction have the center of the maximum unconnected portion shifted in the circumferential direction. [Effects of the Invention]

[0008] This invention facilitates the assembly of other components of a laminate and the assembly of components to other components. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a perspective view showing the core according to Embodiment 1 of the present invention. [Figure 2] Figure 2 is a schematic cross-sectional view of the core in Figure 1, taken along line II-II. [Figure 3] Figure 3 is a schematic unfolded view showing the inner circumference of the core in Figure 1. [Figure 4] Figure 4 is a schematic cross-sectional view of the core related to the comparative example. [Figure 5] Figure 5 is a schematic unfolded view showing the inner circumference of a core according to a modified example of Example 1. [Figure 6] Figure 6 is a schematic unfolded view showing the inner circumference of a core according to another modified example of Example 1. [Figure 7] Figure 7 is a schematic unfolded view showing the inner circumference of a core according to yet another modification of Example 1. [Figure 8] Figure 8 is a schematic unfolded view showing the inner circumference of a core according to yet another modification of Example 1. [Figure 9] Figure 9 is a schematic cross-sectional view showing the joint portion of the core according to Embodiment 2 of the present invention. [Figure 10]Figure 10 is a schematic unfolded view showing the inner circumference of a core according to a modified example of Example 2. [Modes for carrying out the invention]

[0010] The objective of facilitating the assembly of other components and their connection was achieved by circumferentially shifting the center of the largest unconnected section, which has the maximum circumferential dimension within each block, between adjacent blocks of the stacked blocks.

[0011] In other words, the laminate 1 comprises a plurality of blocks 5, connecting parts 9, and unconnected parts 11. The plurality of blocks 5 are formed by stacking a plurality of plate materials 7, and are stacked on each other in the stacking direction of the plate materials 7. The connecting parts 9 connect the plurality of plate materials 7 of each block 5 in the stacking direction. The unconnected parts 11 are the parts of each block 5 that do not have connecting parts 9.

[0012] In each block 5, the maximum non-connected portion 11A, which has the largest circumferential dimension, extends over a range with a central angle of 90 degrees or more. In each block 5, the gap 5b between adjacent plate materials 7 in the stacking direction is larger than the connected portion 9 at least at the circumferential central portion 11Aa of the maximum non-connected portion 11A. In adjacent blocks 5 in the stacking direction, the central portion 11Aa of the maximum non-connected portion 11A is offset in the circumferential direction.

[0013] The largest unconnected portion 11A may have elasticity due to the gap 5b.

[0014] The circumferential displacement of the central portion 11Aa of the maximum unconnected portion 11A can be set as appropriate, but in one embodiment it may be 30 degrees or more.

[0015] The joint 9 should be able to connect the plate materials 7 using an appropriate method. In one embodiment, the joint 9 may consist of either a welded portion or a crimped portion, or both.

[0016] The manufacturing method of the laminate 1 stacks a plurality of blocks 5 in which a plurality of plate materials 7 are stacked in the stacking direction of the plate materials 7, and joins the plurality of plate materials 7 of each block 5 in the stacking direction to form a joint portion 9 and forms a non-joint portion 11 without a joint portion 9 of each block 5.

[0017] At this time, in each block 5, the maximum non-joint portion 11A, which is the non-joint portion 11 having the largest dimension in the circumferential direction, extends over a range of a central angle of 90 degrees or more. Further, the gap 5b between the plate materials 7 adjacent in the stacking direction of each block 5 is made larger than the joint portion 9 at least at the circumferential central portion 11Aa of the maximum non-joint portion 11A. Furthermore, the central portions 11Aa of the maximum non-joint portions 11A of adjacent blocks 5 are shifted from each other in the circumferential direction.

[0018] The plurality of blocks 5 may be stacked while shifting the phases.

Example

[0019] [Core] FIG. 1 is a perspective view showing a core according to Embodiment 1 of the present invention. FIG. 2 is a schematic cross-sectional view taken along line II-II of the core of FIG. 1. FIG. 3 is a schematic development view showing the inner circumference of the core of FIG. 1. In the development view of FIG. 3, the interval between adjacent two-dot chain lines corresponds to a range of 90 degrees in the circumferential direction.

[0020] The core 1 which is the laminate of this embodiment is a core of a rotating electric machine, particularly a rotor core. However, the core 1 can also be a stator core. This core 1 is columnar as a whole and is formed in a cylindrical shape in this embodiment.

[0021] A hole 1a is formed to penetrate in the vertical direction of FIGS. 1 to 3 at the center of the core 1. For example, a shaft which is another member is fitted into this hole 1a. Note that the core 1 may have a key on the inner circumference of the hole 1a. Further, the core 1 may have a magnet insertion hole or the like for inserting a permanent magnet around the hole 1a.

[0022] As shown in Figures 2 and 3, this core 1 comprises multiple blocks 5 stacked with a phase shift. In this embodiment, there are four stacked blocks 5. However, the number of blocks 5 is arbitrary and may be three or fewer, five or more, etc.

[0023] The process of stacking multiple blocks 5 while shifting their phases is called shifting. The phase of a block 5 is the circumferential position of an arbitrary reference point of the block 5, and refers to the rotational state of the block 5 in the circumferential direction. The circumferential direction is the direction along the outer circumference of the core 1 or block 5. The stacking direction is the direction in which the core pieces 7 and blocks 5, described later, are stacked, and coincides with the vertical direction in Figures 1 to 3. The rotational direction is the rotational direction around the axis of the core 1, and in this embodiment coincides with the circumferential direction. The radial direction is the direction along the diameter of the core 1.

[0024] Block 5 refers to a collection of multiple core pieces 7 joined together by the same joint 9, which will be described later. In this embodiment, Block 5 is the unit into which the stacking is performed.

[0025] Each of the multiple blocks 5 is constructed by stacking a predetermined number of core pieces 7 in the same phase, and has a predetermined height in the stacking direction. In Figure 2, for convenience, each block 5 is made up of three core pieces 7, fewer than the actual number. Note that the multiple blocks 5 may have different heights in the stacking directions. Each block 5 has a hole 5a in the center when viewed from above, which forms a hole 1a.

[0026] Each core piece 7 is a sheet material punched out from an electrical steel sheet (not shown). In this embodiment, the core piece 7 is disc-shaped and has a perforated piece 7a on its inner circumference that constitutes the hole 5a of the block 5. The thickness of the electrical steel sheet is not perfectly uniform and has variations (thickness deviation), and accordingly, the core piece 7 may also have a thickness deviation.

[0027] Each block 5 has a connecting portion 9 and an unconnected portion 11.

[0028] The joint 9 connects multiple core pieces 7 in the stacking direction. In this embodiment, the joint 9 is a welded joint. That is, the joint 9 connects multiple core pieces 7 within the block 5 in the stacking direction by welding in that direction. The joint 9 can also be formed on the outer circumference of the core pieces 7.

[0029] In this embodiment, the joint portion 9 is formed at one location in the circumferential direction within each block 5. This single joint portion 9 is formed over a range where the central angle is 90 degrees in the circumferential direction. The size of the joint portion 9 in the circumferential direction can be set arbitrarily, but the central angle is limited to a range of 270 degrees.

[0030] A single joint 9 may be a single linear weld, or it may be a collection of multiple linear welds. Multiple collections of linear welds can be considered a single joint 9 if they are separated circumferentially by non-joint sections of less than 90 degrees, for example. In this embodiment, for convenience, a single joint 9 will be described as a single linear weld. Note that joints 9 may be provided at multiple locations in the circumferential direction.

[0031] The connecting portion 9 extends across the entire area of ​​block 5 in the stacking direction and reaches a portion of the adjacent block 5. This fixes each block 5 and connects adjacent blocks 5. The portion of the adjacent block 5 that the connecting portion 9 reaches is only enough to enable the connection between the blocks 5, for example, a few percent of the height of block 5.

[0032] The unconnected portion 11 is the part of each block 5 that does not have a connecting portion 9. The number and circumferential size of the unconnected portion 11 are determined according to the number of connecting portions 9. In this embodiment, a single unconnected portion 11 is formed over a range of 270 degrees in the circumferential direction with a central angle. Therefore, in this embodiment, this single unconnected portion 11 becomes the largest unconnected portion 11A with the largest circumferential dimensions.

[0033] As described above, the maximum unconnected portion 11A extends over a range of 270 degrees, where the central angle is 90 degrees or more. Note that the circumferential dimensions of the maximum unconnected portion 11A do not need to be constant across multiple blocks 5; they can be different for some or all of the blocks 5.

[0034] The gap 5b between adjacent core pieces 7 in the stacking direction of each block 5 is larger than the gap 9 at least in the central part 11Aa in the circumferential direction of the largest unconnected portion 11A. In this embodiment, there is no gap 5b between the core pieces 7 at the gap 9, and the gap 5b gradually increases towards the central part 11 in the circumferential direction of the largest unconnected portion 11A. The size of the gap 5b in the central part 11Aa of the largest unconnected portion 11A is set to be less than or equal to, for example, the thickness of the core piece 7.

[0035] Furthermore, the gap 5b does not need to be uniform in the stacking direction of the central part 11Aa of block 5. For example, it is sufficient if the largest gap 5b in the central part 11Aa of block 5 is larger than the gap in the joint 9.

[0036] Due to this gap 5b, each block 5 has elasticity in the stacking direction at the maximum unconnected portion 11A and is expandable and contractible at the maximum unconnected portion 11A. Note that the maximum unconnected portion 11A does not need to be elastic; it is sufficient that the gap 5b allows for expansion and contraction of the maximum unconnected portion 11A. This expansion and contraction allows the hole 1a of the core 1 to be straightened relative to the shaft when the shaft is assembled into the hole 1a, as will be described later.

[0037] To correct this hole 1a, the maximum unconnected portion 11A is made to extend over a range of 90 degrees or more in central angle, as described above. If the range of the maximum unconnected portion 11A is less than 90 degrees in central angle, the expansion and contraction of the maximum unconnected portion 11A is limited by the connecting portion 9, and the correction of the hole 1a relative to the axis tends to be small.

[0038] The central portion 11Aa of the largest non-bonded section 11A is shifted circumferentially between adjacent blocks 5 in the stacking direction. This shift refers to the shift between corresponding parts, such as between the centers of the central portion 11Aa. In this embodiment, the shift of the central portion 11Aa is 180 degrees.

[0039] The angle of displacement is preferably 30 degrees or more, more preferably 45 degrees or more, and even more preferably 90 degrees or more. Even a slight displacement of the central part 11Aa of the largest unconnected part 11A of block 5 allows for correction of the orientation of hole 1a relative to the axis. However, if this angle of displacement is 30 degrees or more, the expandable portion of core 1 is less likely to be limited to a certain range in the circumferential direction. In other words, correction of hole 1a relative to the axis is easier.

[0040] [Core manufacturing method] In this embodiment, the manufacturing method for the core 1 involves stacking multiple blocks 5 in the stacking direction of the core pieces 7, as shown in Figures 2 and 3.

[0041] Each block 5 is formed by stacking multiple punched core pieces 7 in the thickness direction. The core pieces 7 are punched out, for example, by a progressive press that presses the core pieces 7 while feeding a strip of electromagnetic steel sheet in one longitudinal direction. The stacking of the core pieces 7 can be done, as is well known, for example, by sequentially holding multiple punched core pieces 7 in a die (not shown). However, the multiple punched core pieces 7 may be stacked outside the die. Within block 5, the stacked state of the core pieces 7 may be temporarily held by crimping, bonding, or the like.

[0042] The stacking of blocks 5 can be performed outside the die by sequentially ejecting multiple blocks 5, each consisting of multiple core pieces 7, from the die. However, the stacking may also be done by holding the multiple blocks 5 inside the die. Alternatively, the core pieces 7 may be stacked in quantities sufficient for multiple blocks 5, effectively creating stacked blocks 5.

[0043] In this embodiment, the stacking of block 5 is performed by a roll stack while shifting the phase of block 5. Therefore, the block 5 to be stacked is stacked on top of the previous block 5, or the previous block 5 is rotated by a predetermined angle around its axis. By performing this roll stack of block 5, tilting after stacking due to thickness deviations of the core pieces 7 is suppressed. Note that block 5 may also be stacked without rotating it around its axis.

[0044] Next, multiple core pieces 7 are joined to the stacked blocks 5 in the stacking direction to form a joint 9. Alternatively, the joint 9 may be formed on each of the multiple blocks 5 beforehand, and the blocks 5 may be joined separately after the multiple blocks 5 have been stacked. In this case, a joint 9 would also be formed on each of the stacked blocks 5. In other words, it is sufficient that a joint 9 is formed on the final stacked blocks 5, and the formation of the joint 9 within each block 5 and the stacking of the blocks 5 may occur first or simultaneously.

[0045] In this embodiment, the joint portion 9 is formed by welding. Specifically, in a stacked state of multiple blocks 5, the joint portion 9 is formed on the inner circumference of each block 5 by welding in the stacking direction. This joint portion 9 connects multiple core pieces 7 within each block 5 in the stacking direction. Furthermore, the joint portion 9 extends to a part of an adjacent block 5, connecting adjacent blocks 5.

[0046] Furthermore, when stacking multiple blocks 5 with pre-formed joints 9, the multiple blocks 5 can be joined together by welding, adhesive, or crimping.

[0047] In this embodiment, the joint portion 9 is formed at one location in the circumferential direction of each block 5, with a central angle in the circumferential direction spanning a range of 90 degrees. As a result, the remaining 270-degree range of each block 5 is occupied by the non-joint portion 11, which is the largest non-joint portion 11A.

[0048] The joint portion 9 of adjacent blocks 5 is located at a position where the central part is 180 degrees apart in the circumferential direction (on opposite sides of the radial center). Accordingly, the largest unjointed portion 11A of adjacent blocks 5 is located at a position where the central part 11Aa is 180 degrees apart in the circumferential direction (on opposite sides of the radial center).

[0049] A gap 5b between core pieces 7 is formed in the central part 11Aa of the largest unconnected portion 11A. Therefore, the gap 5b between adjacent core pieces 7 in the stacking direction of each block 5 is made larger than the connected portion 9, at least in the central part 11Aa in the circumferential direction of the largest unconnected portion 11A. In addition, the central part 11Aa of the largest unconnected portion 11A of adjacent blocks 5 in the stacking direction is shifted in the circumferential direction.

[0050] In this embodiment, the gap 5b is formed by spring-in (spring-go) or spring-back during the formation of the joint 9, as the maximum unjointed portion 11A is provided over a wide area of ​​270 degrees in the circumferential direction. Specifically, the joint 9 is formed while pressing a plurality of stacked blocks 5 in the stacking direction. When the pressurizing force is released after the formation of the joint 9, the spring-in (spring-go) or spring-back that occurs in the joint 9 causes this action to occur between the joint 9 and the unjointed portion 11, making it possible to form a gap 5b in the unjointed portion 11. In this case, increasing the applied pressure tends to increase the gap 5b (elasticity). However, the gap 5b may also be formed by plastic deformation of the core piece 7, etc.

[0051] Once the joint 9 is formed, the stacked blocks 5 are joined together and each block 5 is fixed in place to manufacture the core 1.

[0052] The manufactured core 1 allows for easy assembly of the shaft into the hole 1a. That is, even if the axial direction of each block 5 within the core 1 is inclined with respect to the stacking direction, the hole 1a can be corrected to align with the shaft by expanding or contracting the largest unconnected portion 11A of each block 5 through the gap 5b.

[0053] Therefore, the shaft can be easily and reliably inserted into hole 1a and assembled. If core 1 is a stator core, core 1 can be easily and reliably inserted into the case, which is another component, and assembled.

[0054] Furthermore, in this embodiment, the tolerance range for variations in the orientation of the core pieces 7, block 5, and core 1 during production can be increased, thereby improving the productivity of these core pieces 7, block 5, and core 1.

[0055] Furthermore, in this embodiment, since the largest unconnected portion 11A is elastic, each block 5 can be compressed and then stretched and restored by its elasticity. This makes it easier to assemble the shaft into the hole 1a.

[0056] Furthermore, in this embodiment, since the intermediate portion 11Aa of the largest unconnected portion 11A of each block 5 is offset in the circumferential direction, the accumulation of inclination of the block 5 is easily suppressed, and the shaft can be assembled into the hole 1a more reliably. In addition, because the intermediate portion 11Aa of the largest unconnected portion 11A of the block 5 is offset in the circumferential direction, the core 1 can expand and contract at multiple points in the circumferential direction, making it easier to assemble the shaft into the hole 1a.

[0057] Furthermore, since the circumferential displacement of the central part 11Aa of the largest unconnected portion 11A is 30 degrees or more, the shaft can be inserted into the hole 1a more easily.

[0058] Furthermore, in this embodiment, since the joints 9 of each block 5 are offset in the circumferential direction, the joints 9 are localized and intermittent, which reduces losses due to short circuits between the core pieces 7.

[0059] Figure 4 is a cross-sectional view of the core of the comparative example.

[0060] In Figure 4, the core 1 is constructed such that each block 5 is fixed by multiple connecting parts 9 in the circumferential direction, and multiple blocks 5 are connected to each other. Each block 5 does not have gaps 5b or elastic non-connecting parts 11 as in this embodiment, and its axial direction is inclined with respect to the stacking direction.

[0061] When the block 5 is rolled, the hole 1a of the core 1 becomes zigzag due to the inclination of the hole portion 5a of the block 5. In this case, the diameter of the hole 1a becomes substantially smaller, making it difficult to insert the shaft into the hole 1a. Furthermore, if the core 1 is a stator core, it becomes difficult to insert it into the frame or other components.

[0062] In contrast, in this embodiment, even if the hole 1a has a zigzag shape due to the shifting of the block 5, the shaft can be easily assembled into the hole 1a due to the expansion and contraction of the block 5 at its largest non-connected portion 11A. If the core 1 is a stator core, assembly to a frame or the like becomes easier.

[0063] [Differentiation] Figures 5 to 8 are cross-sectional views showing the inner circumference of a core according to a modified example of Embodiment 1, respectively.

[0064] In the modified example shown in Figure 5, the blocks 5 at both ends of the core 1 in the stacking direction do not have non-connecting portions 11, while the block 5 in the middle of the stacking direction does have non-connecting portions 11. This makes it possible to achieve both the bonding strength of the core pieces 7 at the ends of the core 1 and the ease of assembling the shaft.

[0065] The non-joint portion 11 of the intermediate block 5 is configured in the same way as the non-joint portion 11 of Embodiment 1. At both ends of the block 5 in the stacking direction, the joint portion 9 can be composed of multiple clustered welds that are circumferentially separated from each other and have non-joint portions with a central angle of less than 90 degrees. However, the joint portion 9 of the block 5 at both ends may be composed of a single weld that is continuous in the circumferential direction.

[0066] In the modified example shown in Figure 6, each block 5 of the core 1 is configured in the same way as in Example 1, but the central portion 11Aa of the largest unconnected portion 11A of block 5 is shifted by 90 degrees to one side in the circumferential direction. Note that the direction of the shift of the central portion 11Aa of the largest unconnected portion 11A may be reversed.

[0067] In the modified example shown in Figure 7, the joints 9 of each block 5 are arranged in a single straight line inclined with respect to the stacking direction in the unfolded view. As a result, the joints 9 of the core 1 as a whole form a single helical shape. This means that the start and end points of the welding of the joints 9 are located only at both ends of the core 1 in the stacking direction, minimizing the influence of the start and end points of the welding on the core 1. The inclination direction and angle of the joints 9 can be set as appropriate.

[0068] In the modified example shown in Figure 8, the joint 9 between adjacent blocks 5 is shifted by 180 degrees compared to the modified example in Figure 7. This improves the balance of the circumferential position of the largest unconnected portion 11A throughout the entire core 1.

[0069] These modified examples can also achieve the same effects as in Example 1. [Examples]

[0070] Figure 9 is a cross-sectional view showing the joint portion of the core according to Embodiment 2 of the present invention. Since Embodiment 2 shares the same basic configuration as Embodiment 1, the corresponding components are indicated by the same reference numerals, and redundant explanations are omitted. Refer to Figures 2 and 3 for the cross-sectional view and the unfolded view of the inner circumference of the core.

[0071] In Example 2, the joint portion 9 is formed by a crimped portion. Otherwise, it is the same as in Example 1.

[0072] In other words, the core piece 7 has a recess 13 and a protrusion 15 formed thereon. The recess 13 and protrusion 15 are formed by making one side of the core piece 7 in the thickness direction concave and the other side convex. These recess 13 and protrusion 15 can be formed by pressing.

[0073] This joint 9 is formed along the stacking direction by the engagement of a convex portion 15 into a concave portion 13 between adjacent core pieces 7 within the block 5. Between the blocks 5, the convex portion 15 at the end of one block 5 (upper in Figure 9) engages with the concave portion 13 at the end of the other block 5 (lower in Figure 9). As a result, the joint 9 of one block 5 extends to a part of the other block 5, connecting the blocks 5 together.

[0074] In the other block 5, there is a protrusion 15 on the other side of the recess 13 that constitutes a joint 9 continuous with the other block 5. This protrusion 15 fits into a relief hole 16 provided in the adjacent core piece 7 within the other block 5, forming an unjointed portion 11. In this embodiment, the core piece 7 further adjacent to the core piece 7 having this relief hole 16 (the core piece 7 further down in Figure 9) also has a relief hole 16. The joining of the core pieces 7 within the other block 5 is performed by a joint 9 located 180 degrees different from the joint 9 of the other block 5, as in Embodiment 1.

[0075] Furthermore, the joint portion 9, as in Embodiment 1, extends in the circumferential direction with a central angle of 90 degrees. Therefore, within this range, the joint portion 9 is arranged circumferentially with multiple crimped portions having non-joint portions that extend in a range of less than 90 degrees. However, a single crimped portion may be large enough to extend in a range of 90 degrees.

[0076] Furthermore, the joint 9 may be composed of a crimped portion and a welded portion. For example, the joint 9 may be a welded portion formed by welding in such a way that the crimped portion is burned off. Alternatively, the joint 9 may be composed of a mixture of a crimped portion and a welded portion. These are also true in the modified examples of Example 1. In addition, the joint 9 consisting of a crimped portion can also be applied to the modified examples of Figures 5 and 6 of Example 1.

[0077] In the manufacturing method of this embodiment, a joint portion 9 is formed when multiple blocks 5 are stacked in the stacking direction of the core pieces 7. That is, when the core pieces 7 of each block 5 are stacked sequentially, the protrusions 15 fit into the recesses 13 between adjacent core pieces 7. In this way, a predetermined number of core pieces 7 are stacked to form a block 5 having a joint portion 9.

[0078] Even between adjacent blocks 5, the protrusion 15 at the end of the next block 5 fits into the recess 13 of the joint 9 at the end of the immediately preceding block 5. As a result, the joint 9 of the immediately preceding block 5 extends to a part of the next block 5. Note that adjacent blocks 5 may be joined by adhesive, welding, or other means.

[0079] In this second example, the same effects and advantages as in the first example can be achieved.

[0080] [Differentiation] Figure 10 is a schematic unfolded view showing the inner circumference of a core according to a modified example of Example 2.

[0081] In the modified example shown in Figure 10, the configuration does not have non-joint portions 11 at the ends of adjacent blocks 5 in the stacking direction, compared to Example 2. The ends of adjacent blocks 5 are, for example, composed of multiple clustered crimped portions that are circumferentially separated from each other, with each joint portion 9 having a non-joint portion that extends over a range of less than 90 degrees in central angle.

[0082] In this modified example, it is possible to achieve both the joint strength between the blocks 5 and the ease of assembling the shaft. In addition, the modified example can also achieve the same effects as in Example 2. [Explanation of Symbols]

[0083] 1 core 5 blocks 5b Gap 7 core pieces 9 Joint part 11 Unbonded part 11A maximum uncoupled part

Claims

1. Multiple blocks formed by laminating multiple plate materials, and multiple blocks laminated on each other in the lamination direction of the plate materials, A connecting portion that connects the plurality of plate materials of each block in the stacking direction, Each of the aforementioned blocks comprises a non-connected portion without the aforementioned connecting portion, In each of the aforementioned blocks, the maximum unconnected portion, which is the unconnected portion with the largest circumferential dimension, extends over a range of a central angle of 90 degrees or more. The gaps between adjacent board materials in the stacking direction of each block are larger than the joints at least in the central part of the circumferential direction of the largest non-jointed portion. In the aforementioned stacking direction, adjacent blocks are such that the central portion of the largest unconnected portion is shifted in the circumferential direction. Laminated structure.

2. A laminate according to claim 1, The maximum non-connected portion has elasticity due to the gap, Laminated structure.

3. A laminate according to claim 1, The circumferential displacement of the central portion of the maximum unconnected portion is 30 degrees or more. Laminated structure.

4. A laminate according to claim 1, The aforementioned joint consists of either a welded portion or a crimped portion, or both. Laminated structure.

5. Multiple blocks, each made by stacking multiple plates, are stacked in the direction of stacking the plates. The plurality of plate materials of each block are joined together in the stacking direction to form a joint and a non-jointed portion of each block without the joint, In each of the aforementioned blocks, the maximum unconnected portion, which is the unconnected portion with the largest circumferential dimension, extends over a range of a central angle of 90 degrees or more. The gaps between adjacent plate materials in the stacking direction of each block are made larger than the joints at least in the central part of the circumferential direction of the largest non-jointed portion. The central portion of the largest unconnected part of adjacent blocks in the stacking direction is shifted in the circumferential direction. A method for manufacturing laminates.

6. A method for manufacturing a laminate according to claim 5, The aforementioned multiple blocks are stacked with a phase shift, A method for manufacturing laminates.

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