Stator manufacturing method

Abstract

The present invention provides a method for manufacturing a stator that can prevent interference between the insulating paper and the coil winding when inserting the coil winding into the slot. [Solution] The method for manufacturing a stator includes a stator core preparation step S1 for preparing a stator core having slots, an insulating paper insertion step S2 for inserting insulating paper into the slots, an adsorption step S3 for causing the insulating paper to adhere to the wall surface by generating a negative pressure between the insulating paper inserted into the slots and the wall surface of the slots, and a coil winding insertion step S4 for inserting coil windings into the slots while the insulating paper is adsorbed to the wall surface of the slots.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a stator, and particularly relates to a method for manufacturing a stator of a rotating electrical machine such as a generator or a motor.

Background Art

[0002] A stator of a rotating electrical machine such as a generator or a motor includes a stator core having slots, and coil windings inserted into the slots via insulating paper. When manufacturing a stator having such a structure, for example, as described in Patent Document 1 below, first, a rod-shaped blade having a plurality of suction portions capable of generating negative pressure between itself and the insulating paper is used to suck the insulating paper so as to wind the insulating paper around the blade. Next, the blade is inserted into the slot while the insulating paper is being sucked, and the suction is turned off to dispose the insulating paper in the slot. After that, the coil windings are inserted into the slots of the stator core.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the above-described manufacturing method, the insulating paper inserted into the slot may be displaced from the specified position in the slot, and there also exists variation in the position of the inserted coil winding, so that interference between the insulating paper and the coil winding may occur when inserting the coil winding into the slot. If the insulating paper and the coil winding interfere with each other, the insulating paper may be damaged.

[0005] The present invention has been made to solve such technical problems, and an object of the present invention is to provide a method for manufacturing a stator that can prevent interference between insulating paper and coil windings when the coil windings are inserted into slots. [Means for solving the problem]

[0006] A method for manufacturing a stator according to the present invention is a method for manufacturing a stator comprising a stator core having slots and coil windings inserted into the slots via insulating paper, characterized in that it includes an insulating paper insertion step of inserting the insulating paper into the slots, an adsorption step of generating a negative pressure between the insulating paper inserted into the slots and the wall surface of the slots to cause the insulating paper to adhere to the wall surface, and a coil winding insertion step of inserting the coil windings into the slots while the insulating paper is adsorbed to the wall surface.

[0007] According to the stator manufacturing method of the present invention, in the adsorption step, a negative pressure is generated between the insulating paper inserted into the slot of the stator core and the wall surface of the slot, causing the insulating paper to adhere to the slot wall, thereby allowing the insulating paper to be in close contact with the slot wall. In the coil winding insertion step, the coil winding is inserted into the slot while the insulating paper is adsorbed to the slot wall. That is, in the coil winding insertion step, the coil winding is inserted while the insulating paper is in close contact with the slot wall. This prevents interference between the insulating paper and the coil winding when the coil winding is inserted into the slot. Therefore, it is possible to suppress damage to the insulating paper, tearing of the insulating paper, etc., caused by interference with the coil winding.

[0008] In a preferred embodiment of the stator manufacturing method according to the present invention, the stator core is formed from laminated steel sheets, and in the adsorption step, a negative pressure is generated between the insulating paper and the wall surface of the slot by drawing air from the outer peripheral wall of the stator core. When the stator core is formed from laminated steel sheets in this way, a negative pressure is generated in the gaps of the laminated steel sheets by drawing air from the outer peripheral wall of the stator core. As a result, the insulating paper inserted into the slot is drawn towards the wall surface of the slot, so that the insulating paper can be brought into good contact with the wall surface of the slot. [Effects of the Invention]

[0009] According to the present invention, interference between the insulating paper and the coil winding can be prevented when inserting the coil winding into the slot. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic perspective view showing the status. [Figure 2] This is a partial perspective view showing the stator core. [Figure 3] This is a flowchart showing a method for manufacturing a stator according to an embodiment. [Figure 4] This is a perspective view showing the folded insulating paper and the insertion of the insulating paper. [Figure 5] This is a schematic diagram illustrating the adsorption process. [Modes for carrying out the invention]

[0011] Hereinafter, embodiments of the stator manufacturing method according to the present invention will be described with reference to the drawings. In the following description, unless otherwise specified, "axial direction" refers to the direction along the central axis of the annular central hole of the stator core, in other words, the direction along the rotation axis of the generator or motor inserted into the annular central hole of the stator core. "Radial direction" refers to the radial direction passing through the central axis in a plane perpendicular to the axial direction described above, and "circumferential direction" refers to the direction along the circumference with respect to the central axis. Furthermore, in the following description, "inner circumference side" and "outer circumference side" are based on the center of the annular central hole of the stator core.

[0012] Before explaining the manufacturing method of the stator, the structure of the stator will be described based on Figures 1 and 2.

[0013] [Stator structure] Figure 1 is a schematic perspective view of the stator, and Figure 2 is a partial perspective view of the stator core. As shown in Figure 1, the stator 1, which constitutes a rotating electric machine such as a motor or generator, includes a stator core 10. The stator core 10 includes an annular yoke portion 11 and a plurality of teeth 12, 12... projecting from the inner circumferential surface of the yoke portion 11 toward the center of the yoke portion 11. The spaces between adjacent teeth 12 are slots 13, 13... Note that the number of teeth 12 and slots 13 are the same, and only a portion of them are shown in a simplified view in Figure 1.

[0014] More specifically, the yoke portion 11 is formed in an annular shape along the circumferential direction. The multiple teeth 12, 12... of the stator core 10 extend radially from the yoke portion 11 toward the center of the yoke portion 11. The inner circumferential surfaces of the multiple teeth 12, 12... are formed as curved surfaces, and the inner circumferential space enclosed by the curved surfaces forms the annular central hole of the stator core 10, which is the space in which the rotor (not shown) of a rotating electric machine is arranged.

[0015] As shown in Figure 2, each slot 13 has a pair of side wall surfaces 13a, 13a that extend radially and face each other in the circumferential direction, and a rear wall surface 13b that connects the pair of side wall surfaces 13a, 13a. The pair of side wall surfaces 13a, 13a are parallel to each other so that the spacing on the inner circumference and the spacing on the outer circumference are the same. In contrast, each tooth 12 has a larger circumferential thickness on the outer circumference side and a smaller circumferential thickness on the inner circumference side, and is formed to taper toward the inner circumference. At the inner end of each tooth 12, protrusions 12a, 12a are formed facing each other along the circumferential direction so as to reduce the slot width of each slot 13. The space between the protrusions 12a, 12a is the inner circumference opening 14 of the stator core 10. The rear wall surface 13b constitutes the inner wall surface of the yoke portion 11.

[0016] The stator core 10 is formed of laminated steel sheets. More specifically, the stator core 10 is formed by laminating a predetermined number of, for example, annular magnetic thin plates along the axial direction of the rotating electrical machine. Both surfaces of each magnetic thin plate are each subjected to electrical insulation treatment. As the material of the magnetic thin plate, an electromagnetic steel sheet which is a type of silicon steel sheet or the like is used.

[0017] The stator 1 is, for example, an SC (Segment Conductor) wound stator, and in addition to the stator core 10 described above, further includes: coil windings 15, 15... wound around each of the teeth 12 and inserted into each of the slots 13; and insulating papers 20, 20... disposed in each of the slots 13 and interposed between the stator core 10 and each of the coil windings 15.

[0018] The coil windings 15, 15... are wound around the plurality of teeth 12, 12... and inserted into the plurality of slots 13, 13.... More specifically, each of the coil windings 15 is a split conductor called a segment conductor, which is formed by bending a flat conductor into a substantially U shape, and includes a pair of insertion portions parallel to each other, and a turn portion connecting one ends of the pair of insertion portions. With the insertion portion of the coil winding 15 inserted into the slot 13 in the axial direction, the side opposite to the turn portion is connected by welding or the like to constitute an SC wound coil. When the coil winding 15 constitutes a three-phase distributed winding coil, one phase winding is formed by being wound around the teeth 12 across the plurality of slots 13. The coil winding 15 is formed by winding a flat conductor around each of the teeth 12, skipping the teeth 12 adjacent to the coil winding 15, and is connected, for example, to the second succeeding tooth 12 by distributed winding, and is formed of, for example, three-phase coils of u-phase, v-phase, and w-phase.

[0019] The insulating papers 20, 20... are disposed inside the plurality of slots 13, 13..., and are interposed between the stator core 10 and the coil windings 15, 15... inserted into the slots 13 to electrically insulate the stator core 10 from the coil windings 15.

[0020] The insulating paper 20 has, for example, a 5-layer structure, and includes a sheet-shaped insulating base material, and a foamed adhesive layer and a cover layer respectively arranged on both sides of the insulating base material so as to sandwich the insulating base material. The insulating base material is, for example, electrically insulating with a thickness of about several tens of μm. Examples of the material for the insulating base material include polyethylene naphthalate (PEN), polystyrene (PS), polyethylene terephthalate (PET), polyimide (PI), and heat-resistant amilard.

[0021] The cover layer is the layer arranged on the outermost side of the insulating paper 20, and is formed of, for example, a nonwoven fabric. This cover layer is bonded to the insulating base material via the foamed adhesive layer. The foamed adhesive layer is formed of, for example, a thermosetting resin such as an epoxy resin or a phenol resin containing a foaming agent. The insulating papers 20, 20... having the above structure are inserted and arranged in the slots 13 in a state of being bent into a U-shaped cross section, as will be described later.

[0022] [Method for Manufacturing Stator] As shown in Figure 3, the method for manufacturing a stator according to the present embodiment includes a stator core preparation step S1, an insulating paper insertion step S2, an adsorption step S3, and a coil winding insertion step S4.

[0023] In the stator core preparation step S1, the stator core 10 having the slots 13 is prepared. Specifically, for example, a plurality of annular magnetic thin plates (for example, silicon steel plates) stamped into the same shape are laminated along the axial direction of the rotating electrical machine to manufacture the stator core 10. Both surfaces of each magnetic thin plate are subjected to electrical insulation treatment. The stator core 10 manufactured in the stator core preparation step S1 is, for example, as shown in Figure 2.

[0024] In the insulating paper insertion step S2, the insulating paper 20 is inserted into the slots 13 of the stator core 10. Specifically, first, the insulating paper wound in a roll shape is unwound and cut to a predetermined length. Subsequently, the cut insulating paper is bent into a U-shaped cross section.

[0025] Figure 4 is a perspective view showing the insulating paper in a folded state and the insertion of the insulating paper. As shown in Figure 4, in the folded state, the insulating paper 20 has a pair of opposing side portions 21 and a connecting portion 22 that connects the pair of side portions 21. Also, the height H2 of the insulating paper 20 is slightly greater than the axial height H1 of the stator core 10 (see Figures 2 and 4), and the length L2 of the insulating paper 20 is slightly greater than the radial length L1 of the stator core 10 (see Figures 2 and 4).

[0026] Next, the folded insulating paper 20 is inserted into the slot 13 from the end face side of the stator core 10 perpendicular to the axial direction of the rotating electric machine, such that the pair of side portions 21 face the pair of side walls 13a of the slot 13 and the connecting portion 22 faces the rear wall 13b of the slot 13. Here, the insulating paper 20 is inserted into the slot 13 from the top side of the stator core 10. When inserted into the slot 13, the connecting portion 22 of the insulating paper 20 is in contact with the rear wall 13b of the slot 13, and the pair of side portions 21 are in contact with the side wall 13a of the slot 13.

[0027] As shown in Figure 4, since the height H2 of the insulating paper 20 is slightly greater than the axial height H1 of the stator core 10, when inserted, the insulating paper 20 protrudes slightly from the upper end of the slot 13. Also, since the length L2 of the insulating paper 20 is slightly greater than the radial length L1 of the stator core 10, the tips of the pair of side portions 21 of the insulating paper 20 come close to each other so as to close the opening 14 between the protrusions 12a, 12a of adjacent teeth 12.

[0028] In the adsorption process S3, a negative pressure is generated between the insulating paper 20 inserted into the slot 13 and the wall surface of the slot 13, causing the insulating paper 20 to adhere to the wall surface of the slot 13. At this time, as shown in Figure 5, adsorption is performed using a negative pressure generating device 30 that communicates with the stator core 10. The negative pressure generating device 30 has a shape that surrounds the outer peripheral wall of the stator core 10 and includes an annular suction part 31 detachably attached to the outer peripheral wall of the stator core 10, a vacuum pump 33, and a communication path 32 that connects the suction part 31 and the vacuum pump 33. The suction part 31 has, for example, a plurality of suction ports (not shown) provided at equal intervals along the circumferential direction of the stator core 10.

[0029] Then, the suction unit 31 is attached to the outer periphery of the stator core 10 so that the suction port contacts the outer periphery of the stator core 10. After that, the vacuum pump 33 is turned on to directly draw air from the outer periphery of the stator core 10, thereby generating negative pressure between the insulating paper 20 and the wall surface of the slot 13. Due to the negative pressure, the pair of side portions 21 of the insulating paper 20 are attracted to the pair of side wall surfaces 13a of the slot 13, and the connecting portion 22 of the insulating paper 20 is attracted to the rear wall surface 13b of the slot 13. As a result, the side portions 21 are in close contact with the side wall surface 13a, and the connecting portion 22 is in close contact with the rear wall surface 13b.

[0030] In the coil winding insertion step S4, the coil winding 15 is inserted into the slot 13 while the insulating paper 20 is attached to the wall surface of the slot 13 (more specifically, the side wall surface 13a and the rear wall surface 13b). Specifically, first, the upper end of the insulating paper 20 protruding from the upper end of the slot 13 is spread open using, for example, an insulating paper holding jig (not shown). Next, the pre-prepared coil winding 15 is inserted into the slot 13 from the spread upper end side. At this time, in order to make the insertion of the coil winding 15 smoother, a guide pin (not shown) may be inserted into the slot 13 from the lower side of the stator core 10, and the inserted guide pin may be used to insert the coil winding 15.

[0031] After inserting the coil winding 15, the vacuum pump 33 is turned off to stop air suction. Next, the suction section 31 of the negative pressure generator 30 is removed from the outer circumferential wall of the stator core 10. The manufacturing of the stator 1 is completed by the series of steps described above.

[0032] According to the stator manufacturing method of this embodiment, in the adsorption step S3, a negative pressure is generated between the insulating paper 20 inserted into the slot 13 of the stator core 10 and the wall surface of the slot 13 (more specifically, the side wall surface 13a and the rear wall surface 13b), causing the insulating paper 20 to adhere to the wall surface of the slot 13, thus allowing the insulating paper 20 to be in close contact with the wall surface of the slot 13. In the coil winding insertion step S4, the coil winding 15 is inserted into the slot 13 while the insulating paper 20 is adsorbed to the wall surface of the slot 13. That is, in the coil winding insertion step S4, the coil winding 15 is inserted while the insulating paper 20 is in close contact with the wall surface of the slot 13. This prevents interference between the insulating paper 20 and the coil winding 15 when the coil winding 15 is inserted into the slot 13. Therefore, damage to the insulating paper 20, tearing of the insulating paper 20, etc. caused by interference with the coil winding 15 can be suppressed.

[0033] Furthermore, since damage to the insulating paper 20 caused by interference with the coil windings 15, such as scratches and tears, can be suppressed, damage to the insulating paper 20 can be reduced, making it possible to provide a highly insulated stator 1. Moreover, since interference between the insulating paper 20 and the coil windings 15 can be prevented, the tolerances for processing the stator core 10 can be reduced, and the space required to prevent interference can be reduced. As a result, the conductor space factor can be increased, making it possible to manufacture high-performance rotating electric machines.

[0034] Furthermore, in the adsorption step S3, negative pressure is generated in the gaps between the laminated steel plates by drawing air onto the outer periphery wall of the stator core 10, which is made of laminated steel plates. As a result, the insulating paper 20 inserted into the slot 13 is attracted to the wall surface of the slot 13, allowing the insulating paper 20 to adhere well to the wall surface of the slot 13. Therefore, interference between the insulating paper 20 and the coil winding 15 when inserting the coil winding 15 into the slot 13 can be further prevented.

[0035] Although embodiments of the present invention have been described in detail above, the present invention is not limited to the embodiments described above, and various design modifications can be made without departing from the spirit of the invention as described in the claims. For example, in the coil winding insertion step S4 described above, the coil winding 15 may be inserted directly into the slot 13 without using the insulating paper holding jig. [Explanation of Symbols]

[0036] 1: Stator, 10: Stator core, 11: Yoke section, 12: Teeth, 12a: Protrusion, 13: Slot, 13a: Side wall, 13b: Rear wall, 14: Opening, 15: Coil winding, 20: Insulating paper, 21: Side section, 22: Connecting section, 30: Negative pressure generator, 31: Suction section, 32: Communication path, 33: Vacuum pump

Claims

1. A method for manufacturing a stator comprising a stator core having slots and coil windings inserted into the slots via insulating paper, An insulating paper insertion step of inserting the insulating paper into the slot, A suction step is to generate a negative pressure between the insulating paper inserted in the slot and the wall surface of the slot, thereby causing the insulating paper to adhere to the wall surface. With the insulating paper attached to the wall surface, the coil winding insertion step involves inserting the coil winding into the slot. A method for manufacturing a stator, characterized by including the following:

2. The stator core is formed from laminated steel plates, The method for manufacturing a stator according to claim 1, wherein in the adsorption step, a negative pressure is generated between the insulating paper and the wall surface of the slot by drawing air onto the outer peripheral wall of the stator core.

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