Stator core and method for manufacturing the same

Abstract

The present invention provides a stator core that can suppress misalignment during welding of bolt insertion members to the core body. [Solution] The stator core comprises a cylindrical core body (11) and a plurality of bolt insertion members (20) welded to the outer circumferential surface (11a) of the core body, forming bolt insertion holes that extend in the axial direction of the core body. The bolt insertion members have opposing surfaces that face the outer circumferential surface of the core body, and the opposing surfaces have a welded portion (29) welded to the outer circumferential surface of the core body and a contact portion (22) that abuts against the outer circumferential surface of the core body and is not welded to the outer circumferential surface of the core body.

Description

Technical Field

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

Background Art

[0002] For example, there is a stator core including a cylindrical laminated core and a plurality of rib members each having a bolt insertion portion and joined to the outer peripheral surface of the laminated core and arranged at intervals in the circumferential direction. Each of the plurality of rib members is formed in an inner peripheral surface shape in which both side portions in the circumferential direction of the inner peripheral surface are in contact with the outer peripheral surface of the laminated core, and is welded and fixed to the laminated core in a state where both side portions in the circumferential direction of the inner peripheral surface are in contact with the outer peripheral surface of the laminated core (see Patent Document 1). According to such a configuration, by bringing the rib member and the laminated core into contact with each other along a line extending in the axial direction, the rib member and the laminated core can be brought into contact with each other in a stable state, and a stable welding strength can be obtained.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the stator core (stator core) described in Patent Document 1, both side portions in the circumferential direction of the inner peripheral surface in contact with the outer peripheral surface of the laminated core (core body) in the rib member (bolt insertion member) are welded to the outer peripheral surface of the laminated core. Therefore, during welding, the portion of the rib member supported by the outer peripheral surface of the laminated core melts, and there is a risk that the position of the rib member with respect to the laminated core may shift.

[0005] The present invention has been made to solve the above problems, and its main object is to provide a stator core capable of suppressing the occurrence of displacement during welding of the bolt insertion member with respect to the core body. [Means for solving the problem]

[0006] The first means to solve the above problem is, A cylindrical core body (11) and A stator core (10) comprising a plurality of bolt insertion members (20, 120) welded to the outer circumferential surface (11a) of the core body, forming bolt insertion holes (20a, 120a) extending in the axial direction of the core body, The bolt insertion member has opposing surfaces (21, 21A, 21B, 21C, 121) that face the outer circumferential surface of the core body, The opposing surface has a welded portion (29) welded to the outer circumferential surface of the core body, and a contact portion (22, 22A, 22B, 22C, 122, 122A) that abuts against the outer circumferential surface of the core body and is not welded to the outer circumferential surface of the core body.

[0007] According to the above configuration, the stator core comprises a cylindrical core body and a plurality of bolt insertion members welded to the outer circumferential surface of the core body, forming bolt insertion holes that extend in the axial direction of the core body. Therefore, for example, after attaching the stator coil to the stator core, the stator core can be fixed to the housing by inserting bolts through the bolt insertion members and fastening the bolts to the housing.

[0008] Here, the bolt insertion member has an opposing surface that faces the outer circumferential surface of the core body, and the opposing surface has a welded portion that is welded to the outer circumferential surface of the core body. Therefore, the bolt insertion member is fixed to the outer circumferential surface of the core body at the welded portion of the bolt insertion member. When welding, if the portion of the bolt insertion member that is supported by the outer circumferential surface of the core body melts, there is a risk that the position of the bolt insertion member relative to the core body will shift. In this regard, the opposing surface has a contact portion that abuts against the outer circumferential surface of the core body and is not welded to the outer circumferential surface of the core body. Therefore, even during welding, the contact portion of the bolt insertion member can be supported by the outer circumferential surface of the core body. Thus, it is possible to suppress positional shifts that occur when welding the bolt insertion member to the core body.

[0009] The second method is, A cylindrical core body (11) and A method for manufacturing a stator core (10), comprising a plurality of bolt insertion members (20, 120) welded to the outer circumferential surface (11a) of the core body and forming bolt insertion holes (20a, 120a) extending in the axial direction of the core body, The process of facing the bolt insertion member toward the outer circumferential surface of the core body, The bolt insertion member comprises a contact step of bringing at least a portion of the opposing surfaces (21, 21A, 21B, 21C, 121) that face the outer circumferential surface of the core body into contact with the outer circumferential surface of the core body, A welding step comprising welding a portion of the opposing surface to the outer circumferential surface of the core body, and leaving at least a portion of the portion of the opposing surface that is in contact with the outer circumferential surface of the core body without welding it to the outer circumferential surface of the core body, It is equipped with.

[0010] According to the above manufacturing method, at least a portion of the opposing surface of the bolt insertion member that faces the outer circumferential surface of the core body is brought into contact with the outer circumferential surface of the core body. Therefore, the portion of the opposing surface that comes into contact with the outer circumferential surface of the core body can be supported by the outer circumferential surface of the core body.

[0011] Here, when welding, if the portion of the bolt insertion member supported by the outer peripheral surface of the core body melts, the position of the bolt insertion member with respect to the core body may shift. In this regard, a part of the opposing surface is welded to the outer peripheral surface of the core body, and at least a part of the portion of the opposing surface that abuts against the outer peripheral surface of the core body is left without being welded to the outer peripheral surface of the core body. Therefore, even during welding, the contact portion of the bolt insertion member can continue to be supported by the outer peripheral surface of the core body. Thus, it is possible to suppress the occurrence of positional deviation during welding of the bolt insertion member with respect to the core body.

Brief Description of the Drawings

[0012] [Figure 1] Perspective view of the stator core. [Figure 2] Plan view of the stator core. [Figure 3] Perspective view showing a method of manufacturing the core body. [Figure 4] Schematic diagram showing a method of manufacturing the bolt insertion member. [Figure 5] Plan view showing the state before welding the bolt insertion member. [Figure 6] Plan view showing the welding process of the bolt insertion member. [Figure 7] Plan view showing the welding process of the bolt insertion member of the prior art. [Figure 8] Plan view showing the state after welding the bolt insertion member. [Figure 9] Schematic diagram showing a modified example of the method of manufacturing the bolt insertion member. [Figure 10] Plan view showing the state before welding the bolt insertion member of the modified example. [Figure 11] Plan view showing the welding process of the bolt insertion member of the modified example. [Figure 12] Plan view showing the state before welding the bolt insertion member of another modified example. [Figure 13] Plan view showing the welding process of the bolt insertion member of another modified example. [Figure 14] Plan view showing the state before welding the bolt insertion member of another modified example. [Figure 15] A plan view showing the welding process of the bolt insertion member of another modification example. [Figure 16] A perspective view of a modified example of the stator core. [Figure 17] A plan view of a modified example of the stator core. [Figure 18] A plan view showing the state before welding the bolt insertion member of another modification example. [Figure 19] A plan view showing the welding process of the bolt insertion member of another modification example. [Figure 20] A plan view showing the welding process of the bolt insertion member of another modification example. [Figure 21] A plan view of the electromagnetic steel sheet constituting the core body of the modification example.

Mode for Carrying Out the Invention

[0013] Hereinafter, an embodiment embodied in the stator core of a rotating electrical machine will be described with reference to the drawings.

[0014] As shown in FIGS. 1 and 2, the stator core 10 includes a cylindrical core body 11 and a plurality (for example, three) of bolt insertion members 20. In the following description, the direction in which the central axis of the core body 11 extends is defined as the axial direction, the direction extending radially from the center of the core body 11 is defined as the radial direction, and the direction extending circumferentially around the central axis of the core body 11 is defined as the circumferential direction.

[0015] The core body 11 has an annular back yoke 12. The back yoke 12 extends in the circumferential direction around the central axis of the core body 11. The core body 11 has a plurality of teeth 13 that project radially inward (toward the central axis) from the back yoke 12 and are arranged at a predetermined distance in the circumferential direction. Slots 14 are formed between adjacent teeth 13. The slots 14 open to the inner peripheral side of the core body 11. And a stator coil is provided in a state of being wound around the slots 14 to constitute a stator.

[0016] As shown in Figure 3, the core body 11 is formed by stacking strip-shaped steel plates 19 while winding them around a winding shaft (not shown). In this embodiment, the stator core 10 is a helical stator core. The strip-shaped steel plates 19 are made of, for example, electromagnetic steel sheets which are magnetic. The strip-shaped steel plates 19 are straight before being bent into a spiral shape.

[0017] The bolt insertion member 20 is formed in a groove shape (U-shaped cross-section) and extends in the axial direction. The bolt insertion member 20 is welded to the outer circumferential surface 11a of the core body 11. The bolt insertion member 20 forms an axially extending bolt insertion hole 20a between itself and the outer circumferential surface 11a of the core body 11.

[0018] After attaching the stator coil to the stator core 10, the stator core 10 is fixed to the housing by inserting bolts through the bolt insertion members 20 and fastening the bolts to the housing.

[0019] Figure 4 is a schematic diagram showing the manufacturing method of the bolt insertion member 20. A roll of steel sheet 30 is cut to dimensions corresponding to the dimensions of the bolt insertion member 20 by press punching to form a rectangular plate material 31. The plate material 31 is bent into a groove shape by pressing it along its centerline with a jig to form the bolt insertion member 20. The shape and dimensions of the jig are set so that a space (bolt insertion hole 20a) through which a predetermined bolt can be inserted is formed inside the groove-shaped (U-shaped cross-section) bolt insertion member 20. After that, the longitudinal (axial) end face of the bolt insertion member 20, which will be the seating surface for the bolt, is ground to ensure the flatness and surface roughness of the end face.

[0020] The manufacturing method for the stator core 10 is described below. This manufacturing method is carried out by at least one of a machine and / or a worker.

[0021] Figure 5 is a plan view showing the bolt insertion member 20 before welding. As shown in Figure 4, the bolt insertion member 20 is formed by bending the plate material 31 into a groove shape. Therefore, in the circumferential direction of the groove-shaped bolt insertion member 20, the end of the inner circumferential surface 20b of the bolt insertion member 20 protrudes more than the end of the outer circumferential surface 20c.

[0022] The bolt insertion member 20 is positioned facing the outer circumferential surface 11a of the core body 11 (facing step). Next, the bolt insertion member 20 is pressed radially against the outer circumferential surface 11a, causing the opposing surface 21 of the bolt insertion member 20 that faces the outer circumferential surface 11a to come into contact with the outer circumferential surface 11a (contact step). At this time, both inner ends of the bolt insertion member 20 in the circumferential direction of the core body 11 come into contact with the outer circumferential surface 11a, forming contact portions 22. On the opposing surface 21, parts other than the contact portions 22 do not come into contact with the outer circumferential surface 11a. In the contact step, a part of the opposing surface 21 comes into contact with the outer circumferential surface 11a of the core body 11, and a part of the opposing surface 21 does not come into contact with the outer circumferential surface 11a of the core body 11, that is, at least a part of the opposing surface 21 comes into contact with the outer circumferential surface 11a. As a result, the contact portion 22 that abuts against the outer circumferential surface 11a of the core body 11 on the opposing surface 21 is supported by the outer circumferential surface 11a of the core body 11. The state in which the bolt insertion member 20 abuts against the outer circumferential surface 11a of the core body 11 (positioned state) is maintained by pressing the bolt insertion member 20 against the core body 11 with a jig or the like.

[0023] Figure 6 is a plan view showing the welding process of the bolt insertion member 20. Laser L is irradiated to both outer ends of the bolt insertion member 20 in the circumferential direction of the core body 11, and the bolt insertion member 20 is laser-welded to the outer circumferential surface 11a of the core body 11 (welding process). For example, the bolt insertion member 20 is laser-welded to the outer circumferential surface 11a along its entire axial length. At this time, on the opposing surface 21, the outer circumferential end of the bolt insertion member 20 is welded to the outer circumferential surface 11a, while the contact portion 22, which is the inner circumferential end, is left unwelded to the outer circumferential surface 11a of the core body 11. As a result, a molten portion 28 is formed only on the end of the bolt insertion member 20 on the outer circumferential surface 20c side. That is, in the welding process, a part of the opposing surface 21 is welded to the outer circumferential surface 11a of the core body 11, and the contact portion 22 that is in contact with the outer circumferential surface 11a on the opposing surface 21 is left unwelded to the outer circumferential surface 11a. As a result, during the welding process, the contact portion 22 of the bolt insertion member 20 is continuously supported by the outer circumferential surface 11a of the core body 11. Furthermore, during the welding process, a non-contact portion 23 is left between the contact portion 22 and the molten portion 28 (welded portion) on the opposing surface 21, which does not come into contact with the outer circumferential surface 11a of the core body 11 and is not welded to the outer circumferential surface 11a (forming a non-contact portion 23). As a result, when welding the outer circumferential surface 11a of the core body 11 and the opposing surface 21 of the bolt insertion member 20, the influence of the molten portion 28 on the contact portion 22 is suppressed by the non-contact portion 23.

[0024] Figure 7 is a plan view showing the welding process of a conventional bolt insertion member 920. As shown by the solid line, both outer ends of the bolt insertion member 920 in the circumferential direction of the core body 11 abut against the outer circumferential surface 11a, forming a contact portion 922. As a result, the contact portion 922 that abuts against the outer circumferential surface 11a of the core body 11 on the opposing surface 921 is supported by the outer circumferential surface 11a of the core body 11. A laser L is irradiated onto the outer ends of the bolt insertion member 920 in the circumferential direction of the core body 11 to laser-weld the bolt insertion member 920 to the outer circumferential surface 11a of the core body 11. At this time, the portion of the bolt insertion member 920 supported by the outer circumferential surface 11a of the core body 11 melts, forming a molten portion 28. Therefore, as shown by the dashed line, there is a risk that the position of the bolt insertion member 920 relative to the core body 11 may shift.

[0025] Figure 8 is a plan view showing the state after welding the bolt insertion member 20. The molten portion 28 in Figure 6 has cooled and solidified to become the welded portion 29. The opposing surface 21 of the bolt insertion member 20 has a welded portion 29 that is welded to the outer peripheral surface 11a of the core body 11, and a contact portion 22 that abuts the outer peripheral surface 11a but is not welded to the outer peripheral surface 11a. The welded portion 29 is provided at both outer ends of the bolt insertion member 20 in the circumferential direction of the core body 11. The contact portion 22 is provided at both inner ends of the bolt insertion member 20 in the circumferential direction of the core body 11. Furthermore, the opposing surface 21 of the bolt insertion member 20 has a non-contact portion 23 between the welded portion 29 and the contact portion 22 that does not contact the outer peripheral surface 11a of the core body 11 and is not welded to the outer peripheral surface 11a.

[0026] The embodiment described in detail above has the following advantages.

[0027] The opposing surface 21 of the bolt insertion member 20 has a contact portion 22 that abuts against the outer circumferential surface 11a of the core body 11 and is not welded to the outer circumferential surface 11a of the core body 11. Therefore, even during welding, the contact portion 22 of the bolt insertion member 20 can be supported by the outer circumferential surface 11a of the core body 11. Thus, misalignment during welding of the bolt insertion member 20 to the core body 11 can be suppressed.

[0028] When welding the bolt insertion member 20 to the outer circumferential surface 11a of the core body 11, welding both outer ends of the bolt insertion member 20 in the circumferential direction of the core body 11 is easier than welding the inner portion of the bolt insertion member 20. In this regard, the welded portion 29 is provided at both outer ends of the bolt insertion member 20 in the circumferential direction of the core body 11. Therefore, when welding the bolt insertion member 20 to the outer circumferential surface 11a of the core body 11, both outer ends of the bolt insertion member 20 can be welded in the circumferential direction of the core body 11, thereby improving work efficiency.

[0029] When welding the outer ends of the bolt insertion member 20 in the circumferential direction of the core body 11, it is desirable to maximize the area of ​​the welded portion 29 while suppressing the influence of the welded portion 29 from extending to the contact portion 22. In this regard, the contact portion 22 is provided at both inner ends of the bolt insertion member 20 in the circumferential direction of the core body 11. Therefore, the distance from both outer ends of the bolt insertion member 20 to the contact portion 22 can be increased in the circumferential direction of the core body 11. Thus, the area of ​​the welded portion 29 can be maximized while suppressing the influence of the welded portion 29 from extending to the contact portion 22.

[0030] During the welding process, a portion of the opposing surface 21 is welded to the outer circumferential surface 11a of the core body 11, and at least a portion of the portion of the opposing surface 21 that is in contact with the outer circumferential surface 11a of the core body 11 is left untwelted to the outer circumferential surface 11a of the core body 11. Therefore, even during welding, the contact portion 22 of the bolt insertion member 20 can continue to be supported by the outer circumferential surface 11a of the core body 11. Thus, misalignment during welding of the bolt insertion member 20 to the core body 11 can be suppressed.

[0031] When welding the outer circumferential surface 11a of the core body 11 to the opposing surface 21 of the bolt insertion member 20, the non-contact portion 23 can suppress the effect of heat from welding on the contact portion 22 of the opposing surface 21 that is in contact with the outer circumferential surface 11a of the core body 11. Therefore, melting of the contact portion 22 that is in contact with the outer circumferential surface 11a of the core body 11 can be suppressed during welding, and misalignment between the core body 11 and the bolt insertion member 20 can be further suppressed.

[0032] The bolt insertion member 20 is formed by bending a plate material 31 into a groove shape. As a result, in the circumferential direction of the groove-shaped bolt insertion member 20, the end of the inner circumferential surface 20b of the bolt insertion member 20 tends to protrude more than the end of the outer circumferential surface 20c. Therefore, when welding the bolt insertion member 20 to the outer circumferential surface 11a of the core body 11, contact portions 22 can be naturally provided at both inner ends of the bolt insertion member 20 in the circumferential direction of the core body 11. As a result, the manufacturing cost of the bolt insertion member 20 can be reduced compared to, for example, cutting the bolt insertion member 20 into the above shape before welding.

[0033] The above embodiment can also be implemented with the following modifications. Parts identical to those in the above embodiment are denoted by the same reference numerals, and their descriptions are used accordingly.

[0034] As shown in Figure 9, a strip of steel plate 30 may be bent into a groove shape by roll forming. Then, it is cut to a dimension corresponding to the dimensions of the bolt insertion member 20 to form the bolt insertion member 20. The shape and dimensions of the roll are set so that a space (bolt insertion hole 20a) through which a predetermined bolt can be inserted is formed inside the groove-shaped (U-shaped cross-section) bolt insertion member 20. With this manufacturing method, the bolt insertion member 20 is formed by bending a strip of steel plate 30 into a groove shape. Therefore, in the circumferential direction of the groove-shaped bolt insertion member 20, the end of the inner circumferential surface 20b of the bolt insertion member 20 tends to protrude more than the end of the outer circumferential surface 20c. Thus, the same effects as in the above embodiment can be achieved.

[0035] As shown in Figure 10, the bolt insertion member 20 may have a shape in which the ends of the inner circumferential surface 20b and the outer circumferential surface 20c protrude similarly in the circumferential direction of the groove-shaped bolt insertion member 20. In the contact process, on the opposing surface 21A facing the outer circumferential surface 11a, both inner ends of the bolt insertion member 20 in the circumferential direction of the core body 11 come into contact with the outer circumferential surface 11a to form a contact portion 22A. Then, as shown in Figure 11, on the opposing surface 21A, the end of the bolt insertion member 20 on the outer circumferential surface 20c side is welded to the outer circumferential surface 11a, while the contact portion 22A, which is the end on the inner circumferential side, is left unwelded to the outer circumferential surface 11a of the core body 11. Furthermore, in the welding process, a non-contact portion 23A is left between the contact portion 22A and the molten portion 28 (welded portion) on the opposing surface 21A, which does not come into contact with the outer peripheral surface 11a of the core body 11 and is not welded to the outer peripheral surface 11a (forming a non-contact portion 23A). This makes it possible to achieve the same effects as in the above embodiment.

[0036] As shown in Figure 12, the bolt insertion member 20 may have a shape in which the portion between the end of the inner circumferential surface 20b and the end of the outer circumferential surface 20c is the most protruding in the circumferential direction of the groove-shaped bolt insertion member 20. In the contact process, the protruding portion on the opposing surface 21B facing the outer circumferential surface 11a becomes the contact portion 22B. Then, as shown in Figure 13, on the opposing surface 21B, the end of the bolt insertion member 20 on the outer circumferential surface 20c side is welded to the outer circumferential surface 11a, leaving the contact portion 22B unwelded to the outer circumferential surface 11a of the core body 11. Even with this manufacturing method, the contact portion 22B of the bolt insertion member 20 can be supported by the outer circumferential surface 11a of the core body 11 during welding. Therefore, misalignment during welding of the bolt insertion member 20 to the core body 11 can be suppressed.

[0037] As shown in Figure 14, the bolt insertion member 20 has a groove-shaped shape in which the end of the outer circumferential surface 20c of the bolt insertion member 20 protrudes more than the end of the inner circumferential surface 20b. In the contact process, on the opposing surface 21C facing the outer circumferential surface 11a, both outer ends of the bolt insertion member 20 in the circumferential direction of the core body 11 come into contact with the outer circumferential surface 11a to form a contact portion 22C. Then, as shown in Figure 15, on the opposing surface 21C, the end of the bolt insertion member 20 on the inner circumferential surface 20b side is welded to the outer circumferential surface 11a, while the contact portion 22C, which is the end on the outer circumferential surface 20c side, is left unwelded to the outer circumferential surface 11a of the core body 11. Furthermore, in the welding process, a non-contact portion 23C is left between the contact portion 22C and the molten portion 28 (welded portion) on the opposing surface 21C, which does not come into contact with the outer peripheral surface 11a of the core body 11 and is not welded to the outer peripheral surface 11a (forming a non-contact portion 23C). Although this reduces the workability of laser welding, it is possible to achieve the same effects as in the above embodiment.

[0038] As shown in Figures 16 and 17, the stator core 10 comprises a cylindrical core body 11 and a plurality of bolt insertion members 120. The bolt insertion members 120 are formed in a cylindrical shape and extend in the axial direction. The bolt insertion members 120 can be formed, for example, by casting. The bolt insertion members 120 are welded to the outer circumferential surface 11a of the core body 11. The bolt insertion members 120 form bolt insertion holes 120a that extend in the axial direction.

[0039] As shown in Figure 18, the bolt insertion member 120 has an opposing surface 121 that faces the outer circumferential surface 11a of the core body 11. The opposing surface 121 is formed in a shape that follows the outer circumferential surface 11a. Therefore, in the contact process, the entire opposing surface 121 comes into contact with the outer circumferential surface 11a. Then, as shown in Figure 19, the end of the bolt insertion member 120 on the outer circumferential surface 120c side is welded to the outer circumferential surface 11a on the opposing surface 121, while the remaining contact portion 122 is left unwelded to the outer circumferential surface 11a of the core body 11. This manufacturing method also allows the contact portion 122 of the bolt insertion member 120 to be supported by the outer circumferential surface 11a of the core body 11 during welding. Therefore, misalignment during welding of the bolt insertion member 120 to the core body 11 can be suppressed. In addition, the length of the contact portion 122 between the two molten portions 28 can be increased in the circumferential direction of the core body 11. Therefore, on the opposing surface 121, the contact portion 122 is supported by the outer peripheral surface 11a, while the area of ​​the molten portion 28, and consequently the area of ​​the welded portion, can be made as large as possible.

[0040] Furthermore, as shown in Figure 20, on the opposing surface facing the outer circumferential surface 11a of the core body 11, only the central part of the bolt insertion member 120 in the circumferential direction of the core body 11 may abut against the outer circumferential surface 11a, forming a contact portion 122A. Then, on the opposing surface, the end of the bolt insertion member 120 on the outer circumferential surface 120c side is welded to the outer circumferential surface 11a, leaving the contact portion 122A unwelded to the outer circumferential surface 11a of the core body 11. In addition, during the welding process, a non-contact portion 123A is left between the contact portion 122A and the molten portion 28 (welded portion) on the opposing surface, which does not come into contact with the outer circumferential surface 11a of the core body 11 and is not welded to the outer circumferential surface 11a (forming a non-contact portion 123A). With this manufacturing method, when welding the outer peripheral surface 11a of the core body 11 to the opposing surface of the bolt insertion member 120, the non-contact portion 123A can suppress the effect of heat from welding to the contact portion 122A that is in contact with the outer peripheral surface 11a of the core body 11.

[0041] The bolt insertion member 20 can also be partially laser-welded in the axial direction to the outer circumferential surface 11a of the core body 11.

[0042] The method for welding the bolt insertion members 20 and 120 to the outer circumferential surface 11a of the core body 11 is not limited to laser welding; TIG welding, shielded metal arc welding (consumable electrode type arc welding), etc., can also be used. In short, any welding method can be used that, after welding, leaves a contact portion on the opposing surface of the bolt insertion members 20 and 120 that abuts against the outer circumferential surface 11a of the core body 11 but is not welded to the outer circumferential surface 11a.

[0043] The core body 11 may be formed by laminating annular steel plates 119, as shown in Figure 21. That is, the stator core 10 may be a laminated stator core. The steel plates 119 are formed from, for example, electromagnetic steel plates that are magnetic. Even in this case, the same effects and advantages as those of the above embodiment and its modifications can be achieved.

[0044] Furthermore, the above embodiments and their modifications can be combined and implemented to the extent possible.

[0045] The following describes characteristic methods extracted from each of the embodiments and modifications described above. [Method 1] A cylindrical core body (11) and A method for manufacturing a stator core (10), comprising a plurality of bolt insertion members (20, 120) welded to the outer circumferential surface (11a) of the core body and forming bolt insertion holes (20a, 120a) extending in the axial direction of the core body, The process of facing the bolt insertion member toward the outer circumferential surface of the core body, The bolt insertion member comprises a contact step of bringing at least a portion of the opposing surfaces (21, 21A, 21B, 21C, 121) that face the outer circumferential surface of the core body into contact with the outer circumferential surface of the core body, A welding step comprising welding a portion of the opposing surface to the outer circumferential surface of the core body, and leaving at least a portion of the portion of the opposing surface that is in contact with the outer circumferential surface of the core body without welding it to the outer circumferential surface of the core body, A method for manufacturing a stator core equipped with the above. [Method 2] In the aforementioned contact process, a portion of the opposing surface is brought into contact with the outer circumferential surface of the core body, while a portion of the opposing surface is not brought into contact with the outer circumferential surface of the core body. A method for manufacturing a stator core according to Method 1, wherein in the welding step, a portion of the opposing surface is welded to the outer circumferential surface of the core body to form a welded portion (29), and a non-contact portion (23, 23A, 23C, 123A) is formed between the portion of the opposing surface that is in contact with the outer circumferential surface of the core body and the welded portion, which does not come into contact with the outer circumferential surface of the core body and is not welded to the outer circumferential surface of the core body. [Method 3] A method for manufacturing a stator core according to method 1 or 2, wherein in the welding step, both outer ends of the bolt insertion member in the circumferential direction of the core body are welded to form a welded portion. [Method 4] A method for manufacturing the stator core, wherein the bolt insertion member is formed in a groove shape extending in the axial direction of the core body, A method for manufacturing a stator core according to any one of methods 1 to 3, comprising the step of forming the bolt insertion member by bending a plate-shaped or strip-shaped material (30) into the groove shape. [Explanation of Symbols]

[0046] 10... Stator core, 11... Core body, 11a... Outer circumference, 20... Bolt insertion member, 20a... Bolt insertion hole, 21... Opposing surface, 21A... Opposing surface, 21B... Opposing surface, 21C... Opposing surface, 22... Contact part, 22A... Contact part, 22B... Contact part, 22C... Contact part, 29... Welded part, 120... Bolt insertion member, 120a... Bolt insertion hole, 121... Opposing surface, 122... Contact part, 122A... Contact part.

Claims

1. A cylindrical core body (11), A stator core (10) comprising a plurality of bolt insertion members (20, 120) welded to the outer circumferential surface (11a) of the core body, forming bolt insertion holes (20a, 120a) extending in the axial direction of the core body, The bolt insertion member has opposing surfaces (21, 21A, 21B, 21C, 121) that face the outer circumferential surface of the core body, The stator core has a welded portion (29) welded to the outer circumferential surface of the core body and a contact portion (22, 22A, 22B, 22C, 122, 122A) that abuts against the outer circumferential surface of the core body and is not welded to the outer circumferential surface of the core body.

2. The stator core according to claim 1, wherein the opposing surface has non-contact portions (23, 23A, 23C, 123A) between the welded portion and the contact portion that do not contact the outer circumferential surface of the core body and are not welded to the outer circumferential surface of the core body.

3. The stator core according to claim 1 or 2, wherein the welded portion is provided at both outer ends of the bolt insertion member in the circumferential direction of the core body.

4. The bolt insertion member is formed in a groove shape that extends in the axial direction of the core body. The stator core according to claim 3, wherein the contact portions (22, 22A) are provided at both inner ends of the bolt insertion member in the circumferential direction of the core body.

5. A cylindrical core body (11), A method for manufacturing a stator core (10), comprising a plurality of bolt insertion members (20, 120) welded to the outer circumferential surface (11a) of the core body and forming bolt insertion holes (20a, 120a) extending in the axial direction of the core body, The process of facing the bolt insertion member toward the outer circumferential surface of the core body, The bolt insertion member comprises a contact step of bringing at least a portion of the opposing surfaces (21, 21A, 21B, 21C, 121) that face the outer circumferential surface of the core body into contact with the outer circumferential surface of the core body, A welding step comprising welding a portion of the opposing surface to the outer circumferential surface of the core body, and leaving at least a portion of the portion of the opposing surface that is in contact with the outer circumferential surface of the core body without welding it to the outer circumferential surface of the core body, A method for manufacturing a stator core equipped with the above.

6. In the aforementioned contact process, a portion of the opposing surface is brought into contact with the outer circumferential surface of the core body, while a portion of the opposing surface is not brought into contact with the outer circumferential surface of the core body. A method for manufacturing a stator core according to claim 5, wherein in the welding step, a portion of the opposing surface is welded to the outer circumferential surface of the core body to form a welded portion (29), and a non-contact portion (23, 23A, 23C, 123A) is formed between the portion of the opposing surface that is in contact with the outer circumferential surface of the core body and the welded portion, which does not come into contact with the outer circumferential surface of the core body and is not welded to the outer circumferential surface of the core body.

7. The method for manufacturing a stator core according to claim 5 or 6, wherein in the welding step, both outer ends of the bolt insertion member in the circumferential direction of the core body are welded to form a welded portion.

8. A method for manufacturing the stator core, wherein the bolt insertion member is formed in a groove shape extending in the axial direction of the core body, A method for manufacturing a stator core according to claim 5 or 6, comprising the step of forming the bolt insertion member by bending a plate-shaped or strip-shaped material (30) into the groove shape.

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