Stator and method for manufacturing stator

Abstract

Provided are a stator in which a space factor can be secured and an increase in iron loss can be suppressed, and a method for manufacturing the stator. According to an embodiment, the stator comprises a stator core 10 and a stator winding wound around the stator core 10. The stator core 10 is provided with: divided blocks 13 each comprising block electromagnetic steel sheets which are laminated in the axial direction and in which first outer peripheral side recess parts are formed, each divided block 13 having an outer peripheral surface in which a plurality of block groove parts that extend in the axial direction are formed by the first outer peripheral side recess parts; cut-off plates 12 which are provided adjacent to the divided blocks 13, have an outer periphery having the same diameter as the outer peripheral surface of the divided blocks 13, and are formed with outer peripheral side recess parts 12g at positions corresponding to the block groove parts 13g; and adhesion parts 15 formed in the block groove parts 13g and the outer peripheral side groove parts 12g.

Description

Stator and method for manufacturing the same

[0001] The present invention relates to a stator and a method for manufacturing a stator.

[0002] Stator cores for rotating electrical machines are known to be formed by laminating thin electromagnetic steel sheets to prevent the generation of eddy currents. For such laminated cores, methods such as integrating the laminated electromagnetic steel sheets by welding, integrating them by caulking, or integrating them by applying an adhesive to the surfaces of the electromagnetic steel sheets and laminating them together are used.

[0003] JP 2023-14657 A JP 2021-118664 A

[0004] Among the aforementioned methods of integrating laminated electromagnetic steel sheets by welding, when welding or crimping is used, there is a problem that stress generated during welding or crimping remains in the stator core. There is also a problem that iron loss increases compared to when the electromagnetic steel sheets are simply laminated. There is also a problem that if spatter generated during welding needs to be removed, the number of work steps increases accordingly.

[0005] Furthermore, in the method of applying adhesive to the magnetic steel sheets, there is a problem in that the space factor decreases.

[0006] The problem to be solved by the present invention is to provide a stator and a method for manufacturing the stator that can ensure a space factor and suppress an increase in iron loss.

[0007] In order to achieve the above-mentioned object, a stator according to an embodiment of the present invention is characterized by comprising: a stator core including divided blocks having block electromagnetic steel sheets stacked in the axial direction and having first outer peripheral recesses formed therein, and having a plurality of block grooves on the outer peripheral surfaces thereof that extend in the axial direction and are formed by the first outer peripheral recesses; a slit plate provided adjacent to the divided blocks, having an outer periphery with the same diameter as the outer peripheral surface of the divided blocks, and having second outer peripheral recesses formed at positions corresponding to the block grooves; and adhesive portions formed in the block grooves and the second outer peripheral recesses; and a stator winding wound around the stator core.

[0008] 1 is a longitudinal sectional view showing the configuration of a rotating electric machine according to an embodiment. FIG. 2 is a perspective view showing the overall configuration of a stator core of a stator according to an embodiment. FIG. 3 is a longitudinal sectional view showing the overall configuration of a stator core of a stator according to an embodiment. FIG. 4 is a plan view showing an electromagnetic steel sheet for a block of a stator core of a stator according to an embodiment. FIG. 5 is a plan view showing a cross-section plate of a stator core of a stator according to an embodiment. FIG. 6 is a flow diagram showing the procedure of a method for manufacturing a stator according to an embodiment. FIG. 7 is a flow diagram showing the procedure of a modified example of a method for manufacturing a stator according to an embodiment. FIG. 8 is a flow diagram showing detailed procedures of an assembly step of a temporary laminated core in the procedure of a method for manufacturing a stator according to an embodiment. FIG. 9 is a conceptual diagram explaining the formation of grooves in electromagnetic steel sheets for a block in a method for manufacturing a stator according to an embodiment. FIG. 10 is a conceptual perspective view explaining the relationship between crimping portions of electromagnetic steel sheets for a block of a stator core of a stator according to an embodiment and crimp accommodating holes in the cross-section plate. FIG. 11 is a conceptual perspective view explaining the relationship between divided blocks and the cross-section plate in a method for manufacturing a stator according to an embodiment.

[0009] Hereinafter, a stator and a method for manufacturing the stator according to an embodiment of the present invention will be described with reference to the drawings. Here, identical or similar parts are denoted by common reference numerals, and duplicated explanations will be omitted.

[0010] FIG. 1 is a vertical cross-sectional view showing the configuration of a rotating electrical machine 1 according to the first embodiment.

[0011] The rotating electric machine 1 has a rotor 2, a stator 3, bearings 5, a bearing bracket 6, and a frame 7. The rotor 2 is supported stationarily by the bearings 5 ​​so as to be rotatable around a central rotation axis CL.

[0012] The stator 3 has a stator core 10 arranged radially outside the rotor core of the rotor 2 so as to surround the rotor core via a gap, and a stator winding 4 wound around the stator core 10 .

[0013] Fig. 2 is a perspective view showing the overall configuration of the stator core 10 of the stator 3 according to the embodiment. Fig. 3 is a vertical cross-sectional view showing the overall configuration of the stator core of the stator according to the embodiment.

[0014] During assembly, the stator core 10 has a plurality of divided blocks 13 stacked in the direction of the central axis of rotation CL, and dividing plates 12 arranged between adjacent divided blocks 13. Hereinafter, the direction in which the central axis of rotation CL extends during assembly or a direction parallel to this will be referred to as the axial direction. Each divided block 13 has a plurality of block-forming electromagnetic steel sheets 11 stacked in the axial direction.

[0015] A plurality of stator slots 10s are formed at equal intervals in the circumferential direction on the inner peripheral surface 13u of each divided block 13. Adjacent stator slots 10s form stator teeth 10t.

[0016] Furthermore, block grooves 13g are formed on the outer peripheral surface 13v of each divided block 13 at circumferential intervals, connecting both ends of the divided block 13 in the axial direction. Here, the outer peripheral surface 13v refers to the outer surface of the cylindrical divided block 13 and is also referred to as the side surface. The block grooves 13g of each divided block 13 may be formed in equal numbers in the circumferential direction and at equal intervals. The following describes the case of equal intervals as an example. The angular positions of the block grooves 13g of adjacent divided blocks 13 do not overlap but are offset from each other. That is, one is rotated circumferentially by a predetermined angle from the other. However, the positions of the stator slots 10s overlap each other when viewed in the axial direction. That is, each stator slot 10s has the same shape and can be seen through in the axial direction.

[0017] An adhesive is applied to block grooves 13g formed on the outer peripheral surface 13v of divided blocks 13, forming adhesive portions 15. Adhesive portions 15 bond together block electromagnetic steel sheets 11 that constitute divided blocks 13 during the assembly process of stator 3. Furthermore, as will be described later, when divided block 13 is not at the bottom, block electromagnetic steel sheets 11 that constitute divided block 13 and the underside siding plate 12 are bonded together.

[0018] 4 is a plan view showing block electromagnetic steel sheets 11 of the stator core 10 of the stator 3 according to the embodiment. Block electromagnetic steel sheets 11 are stacked in the axial direction to form one divided block 13. In other words, block electromagnetic steel sheets 11 are electromagnetic steel sheets that constitute divided block 13, and further, together with cross-section plates 12, which are also electromagnetic steel sheets, they are electromagnetic steel sheets that constitute the stator core.

[0019] The block electromagnetic steel sheet 11 has an inner periphery 11u and an outer periphery 11v that are concentric. A plurality of slots 11s are formed in the inner periphery 11u at intervals in the circumferential direction. As a result, a plurality of teeth 11t are formed on the inner periphery 11u side and a ring-shaped yoke portion 11y is formed on the outer side of the teeth 11t. When the block electromagnetic steel sheets 11 are stacked, the slots 11s and teeth 11t form the stator slots 10s and stator teeth 10t of the divided block 13, respectively.

[0020] The yoke portion 11y has a plurality of crimped portions 11b formed at intervals in the circumferential direction. Figure 4 shows an example in which there are four crimped portions 11b. Figure 4 shows an example in which the crimped portions 11b are strip-shaped portions that protrude out of the plane. By forming crimped portions 11b at the same location on each of the block-forming electromagnetic steel sheets 11 in one divided block 13, the connection between the block-forming electromagnetic steel sheets 11 can be ensured. However, other shapes may be used as long as the connection function is ensured. Here, the height of the protrusion out of the plane is equal to or less than the plate thickness of the sluice plate 12 described below.

[0021] A plurality of outer peripheral recesses 11g are formed at intervals in the circumferential direction on the outer periphery 11v. Fig. 4 shows an example in which the outer peripheral recesses 11g are formed in four locations. When the block electromagnetic steel sheets 11 are stacked, the outer peripheral recesses 11g form block grooves 13g of the divided block 13. These outer peripheral recesses 11g function as first outer peripheral recesses.

[0022] FIG. 5 is a plan view showing the siding plate 12 of the stator core 10 of the stator 3 according to the embodiment.

[0023] The crosspiece 12 has an inner periphery 12u and an outer periphery 12v that are concentric. A plurality of slots 12s are formed at intervals in the circumferential direction on the inner periphery 12u. As a result, a plurality of teeth 12t are formed on the inner periphery 12u side and a ring-shaped yoke 12y is formed on the outer side of the teeth 12t.

[0024] As described above, the crossing plates 12 are arranged between two adjacent divided blocks 13 of the multiple divided blocks 13 stacked in the axial direction. For example, let the symbols of the six divided blocks 13 be a, b, c, d, e, and f, and the divided blocks 13 be arranged in this order. Also, let the symbols of the five crossing plates 12 be ABCDE, and let A be between a and b, B between b and c, C between c and d, D between d and e, and E between e and f.

[0025] In this case, the relationship between the dividing plates 12 and the divided blocks 13 is such that A corresponds to a, B to b, C to c, D to d, and E to e. Furthermore, when the stacking direction is vertical, the corresponding relationships are such that A is below a, B is below b, C is below c, D is below d, and E is below e. In other words, the dividing plates 12 are arranged so as to be adjacent to the undersides of the corresponding divided blocks 13. The block electromagnetic steel sheet 11 in the following explanation is that of the divided block 13 directly above the dividing plate 12.

[0026] A crimping hole 12h is formed in the yoke portion 12y of the crosscutting plate 12 at a position corresponding to the crimping portion 11b of the block electromagnetic steel sheet 11. As described above, the height at which the crimping portion 11b of the block electromagnetic steel sheet 11 protrudes out of the surface is equal to or less than the thickness of the crosscutting plate 12. Therefore, the crimping portion 11b of the block electromagnetic steel sheet 11 remains within the crimping hole 12h formed in the crosscutting plate 12 and does not protrude out of the surface on the opposite side of the crosscutting plate 12.

[0027] A plurality of outer peripheral recesses 12g are formed at intervals in the circumferential direction on the outer periphery 12v. FIG. 4 shows an example in which the outer peripheral recesses 12g are formed in four locations. Here, the outer peripheral recesses 12g of the crossing plate 12 are formed at positions corresponding to the outer peripheral recesses 11g formed in the block electromagnetic steel sheet 11 of the corresponding divided block 13, and are formed to be larger (deeper) than the outer peripheral recesses 11g. In other words, they are formed so as to extend further radially toward the center and have a wider circumferential angle in the circumferential direction. These outer peripheral recesses 12g function as second outer peripheral recesses.

[0028] FIG. 6 is a flowchart showing the steps of a method for manufacturing the stator 3 according to the embodiment.

[0029] Broadly speaking, the process includes step S10 for manufacturing the stator core 10, step S20 for manufacturing the stator winding 4, and, after steps S10 and S20, step S30 for winding the stator winding 4 around the stator core 10. That is, the conductors of the stator winding 4 are passed through stator slots 10s formed in the stator core 10 and wound around the stator teeth 10t.

[0030] The procedure of step S10 for manufacturing the stator core will be described below. Note that, although the following description is given taking as an example a case where the electromagnetic steel sheets are stacked in the vertical direction, they may also be placed sideways and stacked in the horizontal direction.

[0031] First, punching oil is applied to a pre-punched electromagnetic steel sheet (step S11). Here, the pre-punched electromagnetic steel sheet is, for example, a rectangular plate-shaped electromagnetic steel sheet purchased from a steel sheet manufacturer. The punching oil used contains metal ions.

[0032] Next, a temporary laminated core is assembled (step S12), the details of which will be described later with reference to FIG.

[0033] Next, adhesive is applied to the side of the temporary laminated core (step S13). The adhesive is dripped from the side of the stator core into the grooves provided on the outer circumferential surface of the stator core. The adhesive used is an anaerobic adhesive with low viscosity that can penetrate between the electromagnetic steel sheets of the laminated core. The viscosity of the adhesive is preferably 50 mPa·s or less, for example.

[0034] Next, pressure is applied during hardening (step S14). Specifically, a cylindrical press with a diameter smaller than that of the preliminary laminated core is used to apply force to the preliminary laminated core from both axial sides. As a result, gaps are formed between the electromagnetic steel sheets that make up the preliminary laminated core on the outer periphery. The formation of these gaps makes it easier for the adhesive to penetrate.

[0035] Next, ultraviolet light is irradiated (step S15), and then the pressure is released (step S16).Then, the stator core is removed (step S17).

[0036] 7 is a flowchart showing the procedure of a modified example of the method for manufacturing a stator according to the embodiment. This modified example differs in that step S11 is replaced by step S11a and step S13a is added.

[0037] The hardening of anaerobic adhesives is accelerated by blocking air (oxygen) in the presence of metal ions. Because the surface of the iron core blank plate is coated with an insulating material, anaerobic adhesives will not harden if used as is, so a solution containing metal ions (primer) is required.

[0038] In step S11, punching oil containing metal ions is applied, but in step S11a of this modified example, punching oil not containing metal ions is applied, and later, just before applying adhesive in step S13, a primer containing metal ions is applied in step S13a. In other respects, there are no differences between the modified examples.

[0039] In this manner, the adhesive portion 15 is formed.

[0040] FIG. 8 is a flowchart showing the detailed procedure of the temporary laminated core assembly step in the procedure of the stator manufacturing method according to the embodiment.

[0041] Now, let N be the number of stacked divided blocks 13 when finishing the temporary laminated core before applying adhesive, and let n be the number of stacked divided blocks 13 up to that point.

[0042] First, the initial value of n is set to n=1 (step S12a).

[0043] Next, the block electromagnetic steel sheets 11 are punched (step S12b). Fig. 9 is a conceptual diagram illustrating the formation of grooves 11g in the block electromagnetic steel sheets 11 in the manufacturing method of the stator according to the embodiment.

[0044] The grooves 11g of the block electromagnetic steel sheets 11 can be formed by using the movable core 31 of the iron core punching die, which can access the block electromagnetic steel sheets 11 from four directions.

[0045] Next, the block electromagnetic steel sheets 11 are stacked (step S12c), and it is determined whether or not a predetermined number of sheets have been stacked (step S12d). If it is not determined that the predetermined number of sheets have been stacked (step S12d NO), steps S12b to S12d are repeated.

[0046] If it is determined that the predetermined number of sheets have been stacked (YES in step S12d), it is then determined whether n is greater than 1 (step S12e).

[0047] If n is greater than 1 (YES in step S12e), the position of the movable core 31 of the core punching die is changed (step S12f), and the slit plate 12 is punched out (step S12g). The divided block 13 is then rotated by a predetermined angle (step S12h). Here, for example, if the block grooves 13g are formed at intervals of an angle Θ in the circumferential direction, the predetermined angle is, for example, (Θ / 2).

[0048] 10 is a conceptual diagram illustrating the formation of the groove 12g in the siding plate 12 in the manufacturing method of the stator according to the embodiment. When forming the groove 12g in the siding plate 12, the movable core 31 of the core punching die used when forming the groove 11g in the block electromagnetic steel sheet 11 can be used so that it overlaps the siding plate 12 from four directions. In this way, the core punching die can be used in common for both the siding plate 12 and the block electromagnetic steel sheet 11.

[0049] To achieve this, the grooves 11g of the block electromagnetic steel sheets 11 are formed so as to widen in the circumferential direction on the radially outer side, so that they have the same shape as the tip of the grooves 12g of the crossbeam 12. Note that the diameter of the crossbeam 12 may be formed smaller than the diameter of the block electromagnetic steel sheets 11 in order to allow the adhesive to penetrate into the crossbeam 12 over the entire circumferential direction. However, in this case, the outer diameter forming portion of the core punching die cannot be shared by the crossbeam 12 and the block electromagnetic steel sheets 11.

[0050] If n is 1 (NO in step S12g), steps S12f to S12h are not performed.

[0051] Next, the divided blocks 13 are mounted (step S12j). Fig. 11 is a conceptual perspective view illustrating the relationship between the divided blocks and the cross-section plate in the manufacturing method of the stator according to the embodiment.

[0052] As a result of the above procedure, as shown in Figure 11, the first divided block 13 is installed as is, and for the second and subsequent divided blocks 13, the dividing plate 12 and the divided block 13 on top of it are mounted. At this time, the dividing plate 12 and the divided block 13 above it correspond to each other and form a single block set 13s. That is, the dividing plate 12 and the divided block 13 above it in the same set are formed with the same shape except for their respective outer peripheral recesses 11g and 12g, as well as the crimped portion 11b and crimp receiving hole 12h. Furthermore, as explained in Figures 9 and 10, the respective outer peripheral recesses 11g and 12g are formed in the same locations, with only the recess depth differing.

[0053] Next, the relationship between the crimped portion 11b and the crimp receiving hole 12h will be described. Fig. 12 is a conceptual perspective view illustrating the relationship between the crimped portion 11b of the electromagnetic steel sheet 11 for the block of the stator core of the stator according to the embodiment and the crimp receiving hole 12h of the cross-section plate 12, as viewed from below.

[0054] The crimped portions 11b formed on each of the block-forming electromagnetic steel sheets 11 protrude outward (downward) from the surface. The block-forming electromagnetic steel sheets 11 are positioned relative to one another by the crimped portions 11b and stacked to form the divided blocks 13.

[0055] The crimping hole 12h of the crossing plate 12 on the lower side of the divided block 13 has a space for accommodating the crimping portion 11b protruding outward (toward the lower side) from the surface of the block electromagnetic steel sheet 11. Therefore, the crimping portion 11b does not protrude from the crossing plate surface 12f of the crossing plate 12.

[0056] The stator and the method for manufacturing the stator according to the present embodiment described above have the following features.

[0057] (1) The block electromagnetic steel sheets 11 that make up the divided blocks 13 are positioned relative to one another using crimping, and are joined by applying adhesive to the block grooves 13g, thereby avoiding the problem of stress caused by welding, etc., remaining in the stator core.

[0058] (2) When multiple divided blocks 13 are provided, the divided blocks 13 can be reliably connected to each other by providing a cross-section plate 12 on the underside of the divided blocks 13, the cross-section plate 12 having a sufficiently large outer recess 12g formed at a position corresponding to the block groove 13g.

[0059] According to the embodiment described above, it is possible to provide a stator and a method for manufacturing a stator that can ensure a space factor and suppress an increase in iron loss.

[0060] [Other Embodiments] Although the embodiments of the present invention have been described above, they are presented as examples and are not intended to limit the scope of the invention. Furthermore, features of each embodiment may be combined. Furthermore, the embodiments may be implemented in various other forms, and various omissions, substitutions, and modifications may be made without departing from the spirit of the invention. The embodiments and their modifications are intended to be included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as set forth in the claims.

[0061] DESCRIPTION OF SYMBOLS 1... rotating electric machine, 2... rotor, 3... stator, 4... stator winding, 5... bearing, 6... bearing bracket, 7... frame, 10... stator core, 10s... stator slot, 10t... stator tooth, 11... electromagnetic steel sheet for block, 11b... crimped portion, 11g... outer peripheral recess (first outer peripheral recess), 11s... slot portion, 11t... tooth portion, 11u... inner periphery, 11v... outer periphery, 11y... yoke portion, 12 ...crossing plate, 12f...crossing plate surface, 12g...outer peripheral recess (second outer peripheral recess), 12h...crimping receiving hole, 12s...slot portion, 12t...teeth portion, 12u...inner periphery, 12v...outer periphery, 13...divided block, 13g...block groove portion, 13s...block assembly, 13u...block inner peripheral surface, 13v...block outer peripheral surface, 14...temporary laminated core, 15...adhesion portion, 20...stator winding, 31...moving core

Claims

1. A stator comprising: a split block having a block electromagnetic steel sheet laminated in the axial direction and formed with a first outer peripheral side recess, and a plurality of block groove portions extending in the axial direction due to the first outer peripheral side recess formed on the outer peripheral surface; a cut-off plate provided adjacent to the split block, having an outer periphery with the same diameter as the outer peripheral surface of the split block, and formed with a second outer peripheral side recess at a position corresponding to the block groove portion; and an adhesive portion formed in the block groove portion and the second outer peripheral side recess; a stator core; and a stator winding wound around the stator core.

2. The stator according to claim 1, wherein the second outer peripheral side recess of the cut-off plate is formed to be deeper than the block groove portion of the split block.

3. The stator according to claim 1, wherein the circumferential positions of the block groove portions in each of the adjacent split blocks are shifted from each other in the circumferential direction.

4. A method for manufacturing a stator, comprising: assembling a temporary laminated core composed of a split block formed with block groove portions on the side surface by laminating block electromagnetic steel sheets and a cut-off plate arranged between the split blocks; and applying an adhesive to the block groove portions formed on the side surface of the temporary laminated core.

5. The method for manufacturing a stator according to claim 4, wherein the assembly of the temporary laminated core includes: punching the cut-off plate; punching the block electromagnetic steel sheet; forming the split block by laminating the block electromagnetic steel sheets; arranging the cut-off plate between the split blocks; and laminating the split blocks.

6. The method for manufacturing a stator according to claim 5, wherein the formation of the first outer peripheral side recess of the block electromagnetic steel sheet in the punching of the block electromagnetic steel sheet and the formation of the second outer peripheral side recess of the cut-off plate in the punching of the cut-off plate are performed by changing the position of the same movable core.

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