Stator, rotating electrical machine, and method for manufacturing stator

Abstract

A stator (100) according to an embodiment of this invention comprises: a stator core (110) in which a plurality of stator slots (111) are formed in the circumferential direction on an inner circumferential surface in a cylindrical shape; a stator winding that is equipped, in each phase, with a plurality of coil segments (130) each comprising linear parts having a rectangular cross-section and accommodated respectively in two mutually-different stator slots (111) and an end part having a rectangular cross-section and connecting two linear parts on the outer side of a first end (110a) in the axial direction of the stator core (110), as well as with a plurality of crossover parts which connect the plurality of coil segments in series on the outside of a second end in the axial direction of the stator core (110); and an adhesive insulation part (142) that is interposed in at least a portion of radially adjacent parts which are radially adjacent to each other in each of a plurality of the end parts. The plurality of linear parts form a plurality of layers in the radial direction in each of the plurality of stator slots, and the radially adjacent parts are bonded to each other by the adhesive insulation part (142).

Description

Technical Field

[0001] The present invention relates to a stator, a rotating electrical machine, and a method for manufacturing a stator.

Background Art

[0002] In motors and generators used in EVs (electric vehicles), PEVs (plug-in electric vehicles), etc., since a large current flows through the stator winding, a flat wire (flat conductor) with a large cross-sectional area is used as the conductor of the stator winding. Therefore, since the connection unit including the flat wire becomes large-sized and causes interference with the peripheral components of the motor, a technique for compactly housing the connection unit near the motor is desired.

[0003] In view of such a situation, in a conventional rotating electrical machine, a method is known in which flat wires are arranged in a plurality of axial layers outward in the axial direction of the coil end of the stator winding to make the connection unit compact.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Motors and generators used in EVs (electric vehicles), PEVs (plug-in electric vehicles), etc. particularly require vibration resistance. In order to wind the stator winding using a flat wire and ensure vibration resistance, conventionally, the stator winding has been fixed with varnish.

[0006] However, since there are variations in the penetration and fixing of the varnish when fixing between windings with varnish, particularly, the reliability of the coil end may decrease.

[0007] An object of the present invention is to provide a stator, a rotating electrical machine, and a method for manufacturing a stator that can stably fix a coil end and ensure reliability against vibration.

Means for Solving the Problems

[0008] To achieve the above object, a stator according to an embodiment of the present invention includes a stator core having a cylindrical shape with a plurality of stator slots formed in the circumferential direction on the inner peripheral surface, and a plurality of coil segments each having a straight portion with a rectangular cross-section partially accommodated in two different stator slots among them and an end portion with a rectangular cross-section connecting the two straight portions outside the first end portion in the axial direction of the stator core, and a stator winding including a plurality of connecting portions connecting the plurality of coil segments in series outside the second end portion in the axial direction of the stator core, and an adhesive insulating portion interposed in at least a part of the radially adjacent portions adjacent to each other in the radial direction in a coil end portion which is a portion outside the first 1 end portion of the stator winding. The stator is characterized in that the adhesive insulating portion is formed by disposing and adhering a foamed adhesive sheet, and the foamed adhesive sheet has a planar base material and foamed adhesive layers applied to both surfaces of the base material respectively. A plurality of the straight portions have portions accommodated in each of the plurality of stator slots forming a plurality of layers in the radial direction, and the radially adjacent portions are coupled to each other by the adhesive insulating portion and , the adhesive insulating portion is arranged at every other radial position among portions at the coil end portions of the straight portions corresponding to each of the plurality of the layers, which is characterized by this.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0010] Hereinafter, with reference to the drawings, a stator, a rotating electrical machine, and a method for manufacturing a stator according to an embodiment of the present invention will be described. Here, the same or similar parts are denoted by common reference numerals, and redundant descriptions are omitted.

[0011] FIG. 1 is a longitudinal sectional view showing an example of a rotating electrical machine 1 having a stator 100 according to the embodiment.

[0012] The rotating electrical machine 1 includes a rotor 10, bearings 21, a bearing bracket 22, a frame 23, and a stator 100.

[0013] The rotor 10 has a rotor shaft 11 extending in the direction of the rotation center axis CL, a rotor core 12 attached to the radially outer side of the rotor shaft 11, a permanent magnet 13 embedded in the rotor core 12, and closing plates 14 provided at both axial ends of the rotor core 12 to prevent the protrusion of the permanent magnet 13. The rotor shaft 11 is rotatably supported at both axial sides by bearings 21, respectively. Further, each bearing 21 is statically supported by a bearing bracket 22.

[0014] The stator 100 has a stator core 110 disposed on the radially outer side of the rotor core 12 with a gap therebetween, and a stator winding 120 that is partially housed in a stator slot 111 (FIG. 2) formed in the stator core 110 and winds around a stator tooth 112 (FIG. 2).

[0015] The stator 100 is housed within a frame 23 arranged to surround the outer radial direction and is statically supported by the frame 23.

[0016] The stator winding 120 has a plurality of coil segments 130 and a plurality of connecting portions 125 that connect these. A rectangular conductor 121 is used for the coil segments 130 and the connecting portions 125.

[0017] Here, each coil segment 130 has two straight portions 131 respectively housed within two different stator slots 111, and a connecting portion 132 that connects these two straight portions 131 on the outer axial side of the first end portion 110a of the stator core 110. Each straight portion 131 is respectively housed within the stator slot 111, and both ends of the straight portion 131 protrude to the outer axial side of the first end portion 110a and the second end portion 110b of the stator core 110.

[0018] The connecting portions 125 respectively connect the straight portions 131 of the coil segments 130 that protrude to the outer axial side of the second end portion 110b.

[0019] FIG. 2 is a partial cross-sectional view showing an example of the rotating electrical machine 1 according to the embodiment.

[0020] A plurality of stator slots 111, which are axial through grooves extending in the axial direction with intervals in the circumferential direction, are formed on the radially inner circumferential surface of the stator core 110. Further, stator teeth 112 are respectively formed by forming the stator slots 111 adjacent to each other in the circumferential direction.

[0021] In each stator slot 111, a plurality of rectangular flat conductors 121, which are straight portions 131 of the coil segment 130 and have a rectangular cross-section, are laminated in the radial direction while being electrically insulated from each other. That is, as shown in FIG. 2, in each stator slot 111, a first-layer conductor 131a, a second-layer conductor 131b, a third-layer conductor 131c, a fourth-layer conductor 131d, a fifth-layer conductor 131e, and a sixth-layer conductor 131f are arranged in this order from the outer side to the inner side in the radial direction. Hereinafter, regardless of the stator slots 111, these flat conductors 121, which are the straight portions 131, shall be referred to as the first-layer conductor 131a, the second-layer conductor 131b, the third-layer conductor 131c, the fourth-layer conductor 131d, the fifth-layer conductor 131e, and the sixth-layer conductor 131f in accordance with the order of their layers.

[0022] FIG. 3 is a perspective view for explaining the coil end of the stator 100 according to the embodiment.

[0023] The coil segment 130 is housed in the stator slot 111 between the stator teeth 112 formed on the inner peripheral surface of the stator core 110, and has a straight portion 131 that partially protrudes from the end of the stator core 110 and a connecting portion 132 that connects between the straight portions 131. The coil end refers to a portion composed of the protruding portion of the straight portion 131 from the first end 110a of the stator core 110 and the connecting portion 132 among the stator windings 120. In other words, the coil end is a portion axially outside the first end 110a of all the coil segments 130 of the stator winding 120.

[0024] Regarding the straight portion 131, within each stator slot 111, the leftmost side in FIG. 3 is the first layer, and the rightmost side, that is, the side closer to the inner peripheral surface, is the sixth layer.

[0025] FIG. 4 is a perspective view showing a conceptual arrangement of the adhesive insulating portion 142 in the coil end 120a of the stator 100 according to the embodiment. FIG. 4 shows the content shown in FIG. 3 with the adhesive insulating portion 142 further added, and the coil end 120a of the stator 100 according to the present embodiment is shown in FIG. 4.

[0026] Next, the insulating portion 142 includes a first adhesive insulating portion 142a shown by a solid line and a second adhesive insulating portion 142b shown by a broken line. The positions on the cylindrical curved surfaces with the same distance from the rotation center axis CL are considered to have the same radial position or to be the radial positions.

[0027] The first adhesive insulating portion 142a is arranged axially at a position visible from the axial end face of the coil end 120a. The first adhesive insulating portion 142a is arranged at or near each of the radial positions between the second and third layers, between the fourth and fifth layers, between the sixth and seventh layers, and between the seventh and eighth layers.

[0028] Also, the second adhesive insulating portion 142b has a portion where the coil end changes lanes (the portion where the layers change), and in the vicinity thereof, it is not directly visible from the axial end face. The second adhesive insulating portion 142b is arranged at or near each of the radial positions between the first and second layers and between the third and fourth layers.

[0029] Therefore, the adhesive insulating portion 142, that is, the first adhesive insulating portion 142a and the second adhesive insulating portion 142b, are both arranged between the flat conductors 121 adjacent to each other in the radial direction.

[0030] Here, if the vibration resistance of the coil end 120a is ensured, the adhesive insulating portion 142 does not need to extend over the entire circumference and may be arranged partially in the circumferential direction. Also, it does not need to be arranged between all the layers. For example, it may be arranged at intervals.

[0031] As will be described later, the adhesive insulating portion 142 is a portion formed by foaming and adhering a foaming adhesive sheet 141 (Fig. 5) set at that position by raising the temperature. By the foaming adhesive sheet 141 becoming the adhesive insulating portion 142, each part of the coil end 120a is adhered and fixed to each other.

[0032] FIG. 5 is a longitudinal sectional view showing a foamed adhesive sheet 141 used for fixing the coil ends of the stator according to the embodiment.

[0033] The foamed adhesive sheet 141 has a planar base material 141a and foamed adhesive layers 141b applied to both surfaces of the base material 141a, respectively. The base material 141a is, for example, a film mainly made of a polymer material. The foamed adhesive layer 141b generates foaming and adhesion functions by raising the temperature. The adhesive insulation part 142 shown in FIG. 3 is formed by the foamed adhesive sheet 141 reaching a high temperature during the stator assembly process, thereby generating foaming and adhesion functions.

[0034] FIG. 6 is a flowchart showing the procedure of the method for manufacturing a stator according to the embodiment.

[0035] First, in the coil end holding jig, a plurality of coil segments 130 and a plurality of foamed adhesive sheets 141 to be interposed are sequentially laminated (step S01).

[0036] FIG. 7 is a conceptual perspective view for explaining the use of the coil end holding jig in the method for manufacturing a stator according to the embodiment.

[0037] The coil end holding jig 200 has an inner cylinder 201, an outer cylinder 202, and a bottom part 203 connecting the lower end of the inner cylinder 201 and the lower end of the outer cylinder 202. That is, as shown in FIG. 7, the coil end holding jig 200 is a container having an annular storage space 205, and the inner cylinder 201 and the outer cylinder 202 are arranged concentrically.

[0038] The storage space 205 is formed to have a size capable of storing the coil end 120a protruding axially from the first end 110a of the stator core 110.

[0039] In step S01, for example, as shown in FIG. 7, with the connection part 132 of the coil segment 130 facing downward and the straight part 131 of each coil segment 130 facing vertically upward, each coil segment 130 is sequentially placed on the bottom 203 of the coil end holding jig 200. At this time, the foam adhesive sheet 141 is sandwiched at necessary positions.

[0040] Specifically, for example, like the coil segment 130a among the coil segments 130, the foam adhesive sheet 141, and the coil segment 130b among the coil segments 130, they are installed in the circumferential direction for the inner side in the radial direction, and sequentially, the installation range is expanded to the outer side in the radial direction. In addition, in order to stably install each coil segment 130 on the bottom 203, the coil end holding jig 200 is provided with receivers for each coil segment 130, but the illustration is omitted.

[0041] In this way, the entire coil segment 130 with the foam adhesive sheet 141 sandwiched as necessary is installed on the coil end holding jig 200. As a result, with the coil end 120a on the lower side, the straight part 131 of each coil segment 130 extends vertically upward.

[0042] Next, the stator core 110 is lowered from above toward the coil end holding jig 200 with the first end 110a facing downward, and each straight part of the connecting part is inserted into each stator slot (step S02). As a result, the straight part 131 of each coil segment 130 protrudes from the second end 110b of the stator core 110.

[0043] Next, a foam adhesive sheet is inserted between the radially spaced coil segments 130 protruding from the second end 110b of the stator core 110 (step S03).

[0044] Next, the straight portions 131 of the respective coil segments 130 protruding from the second end portion 110b of the stator core 110 are bent to connect the straight portions 131 to each other (step S04). As a result, the stator winding 120 is wound around the stator core 110. Further, connection from the straight portion 131 of a predetermined coil segment 130 to the neutral point and attachment of an external terminal to the straight portion 131 of the predetermined coil segment 130 are performed.

[0045] Next, the stator 100 in which the stator winding 120 is wound around the stator core 110 is heated (step S05). Here, the heating is performed at a temperature at which the foaming adhesive sheet 141 foams and an adhesive function is generated, and at the lowest possible temperature. This prevents any influence on each insulating member (not shown) other than the foaming adhesive sheet 141. As a result, the foaming adhesive layer 141b of the foaming adhesive sheet 141 foams to become the adhesive insulating portion 142. In this way, two coil segments 130 that are partially adjacent to each other adhere to each other via the base material 141a and are electrically insulated from each other by the base material 141a.

[0046] Next, other members are attached (step S06).

[0047] According to the above procedure, the foaming adhesive sheet 141 can be installed at any location.

[0048] In the above embodiment, for the flat conductor 121 of the straight portion 131 in the stator slot 111, before inserting it into the stator slot 111, an insulating portion is formed by attaching slot insulating paper 145 to the flat conductor 121 of the straight portion 131. At this time, when the slot insulating paper 145 is merely insulating paper, varnish is disposed between the slot insulating paper 145 and the winding. On the other hand, when the slot insulating paper 145 is the slot insulating paper 145a made of the foaming adhesive sheet 141, varnish is unnecessary, and the consumption amount of the conventionally used varnish can be further reduced.

[0049] According to the embodiments described above, it is possible to provide a stator, a rotating electrical machine, and a method for manufacturing a stator that can stably fix a coil end and ensure reliability against vibration.

[0050] [Other Embodiments] Although the embodiments of the present invention have been described above, the embodiments are presented as examples and are not intended to limit the scope of the invention. Also, the features of each embodiment may be combined. Furthermore, the embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. The embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalent scope thereof.

Explanation of Reference Numerals

[0051] 1... Rotating electrical machine, 10... Rotor, 11... Rotor shaft, 12... Rotor core, 13... Permanent magnet, 14... Closing plate, 21... Bearing, 22... Bearing bracket, 23... Frame, 100... Stator, 110... Stator core, 110a... First end, 110b... Second end, 111... Stator slot, 112... Stator tooth, 120... Stator winding, 120a... Coil end, 121... Flat conductor, 125... Crossing portion, 130, 130a, 130b... Coil segment, 131... Straight portion, 131a... First layer conductor, 131b... Second layer conductor, 131c... Third layer conductor, 131d... Fourth layer conductor, 131e... Fifth layer conductor, 131f... Sixth layer conductor, 132... Connection portion, 141... Foam adhesive sheet, 141a... Base material, 141b... Foam adhesive portion, 142... Adhesive insulating portion, 142a... First adhesive insulating portion, 142b... Second adhesive insulating portion, 145... Slot insulating paper, 200... Coil end holding jig, 201... Inner cylinder, 202... Outer cylinder, 203... Bottom, 205... Storage space

Claims

1. A stator core that is cylindrical and has a plurality of stator slots formed in the circumferential direction on the inner peripheral surface, A plurality of coil segments each having a straight portion with a rectangular cross-section, a part of which is respectively accommodated in two different stator slots, and a connecting portion with a rectangular cross-section that connects the two straight portions outside the first end portion in the axial direction of the stator core, and, outside the second end portion in the axial direction of the stator core, a plurality of connecting portions that connect the plurality of coil segments in series, and an adhesive insulating portion that intervenes in at least a part of the radially adjacent portions that are adjacent to each other in the radial direction at the coil end portion, which is a portion outside the first end portion of the stator winding, A stator comprising: The adhesive insulating portion is formed by disposing and adhering a foamed adhesive sheet, The foamed adhesive sheet has a planar base material and foamed adhesive layers respectively applied to both surfaces of the base material, In the plurality of straight portions, the portions accommodated in the respective plurality of stator slots form a plurality of layers in the radial direction, The radially adjacent portions are coupled to each other by the adhesive insulating portion, The adhesive insulating portion is disposed at every other radial position among the portions at the coil end portion of the straight portions corresponding to the respective plurality of layers, A stator characterized by the above.

2. In the plurality of stator slots, the slot insulating paper used is either mere insulating paper or the slot insulating paper of the foamed adhesive sheet. In the case of mere insulating paper, varnish is disposed between the insulating paper and the stator winding. In the case of the slot insulating paper of the foamed adhesive sheet, there is no varnish between the slot insulating paper and the stator winding. The stator according to claim 1, characterized by the above.

Images