WO2020031612A1

WO2020031612A1 - Stator for rotary electric machine and manufacturing method for same

Info

Publication number: WO2020031612A1
Application number: PCT/JP2019/027638
Authority: WO
Inventors: 中山　健一; 堀　俊夫; 博光岡本; 雄貴荒井; 雄志金野; 佐藤　俊一郎
Original assignee: 日立オートモティブシステムズ株式会社
Priority date: 2018-08-09
Filing date: 2019-07-12
Publication date: 2020-02-13
Also published as: JPWO2020031612A1; JP7061194B2

Abstract

The present invention addresses the problem of improving the rigidity of a welded part. A stator for a dynamo-electric machine, said stator comprising: a stator core for which a plurality of radially opening slots are formed aligned in the circumference direction; and a plurality of segment coils disposed in the radial direction of the stator inside the slots. The plurality of segment coils have: a plurality of welded parts formed on the respective end parts of the plurality of segment coils exposed at the outside of the slots, the welded parts connecting adjacent segment coils; and an insulating coating part that coats the plurality of welded parts, and connects the welded parts in the radial direction of the stator. On at least one more of the plurality of welded parts is formed a projecting part that projects to the radially inner circumference side or outer circumference side from the side surface of the segment coil.

Description

Stator for rotating electric machine and method of manufacturing the same

The present invention relates to a stator for a rotating electric machine and a method for manufacturing the stator.

The rotating electric machine generates a rotating magnetic field by supplying AC power to the stator coil, and can rotate the rotor with the rotating magnetic field. Further, it is also possible to convert mechanical energy applied to the rotor into electric energy and output AC power from the coil. Thus, the rotating electric machine operates as a motor or a generator.

背景 The following prior arts are background arts in this technical field. Patent Literature 1 (Japanese Patent Application Laid-Open No. 2011-54263) discloses that a molten portion formed by melting a tip portion of an end portion of a pair of conductor segments is solidified while urging the melted portion to one side in a circumferential direction, thereby forming a fusion mark, that is, joining A rotating electric machine is described in which an end is formed so as to be bulged to one side in a circumferential direction.

Patent Document 2 (International Publication No. 2013/99001) discloses a segment coil and a segment coil formed by bending a rectangular conductor to provide a rotating electric machine that realizes downsizing of the rotating electric machine and improvement of weldability. In a rotating electric machine having a stator core having a slot into which the stator coil is inserted, a welded portion formed at the tip of a lead portion of a segment coil that is projected and twisted from an end face of the stator core is formed in a radial direction of the stator. At least one of the welding balls arranged in a circle is a long ellipsoid that is long in the radial direction of the stator core, and the angle formed by the longitudinal direction of the long ellipsoid and the axial direction of the stator core includes the central axis of the stator core. A fire IT year electric machine with a core cut surface shape smaller than 90 degrees is described.

Patent Document 3 (Japanese Patent Application Laid-Open No. 2016-93027) discloses that, in a rotating electrical machine stator including a stator coil and a plurality of caps formed of an insulating material, the stator coil has a plurality of radial positions at a plurality of circumferential positions at a coil end. And has a plurality of joints each of which is a joint of a conductor. Each cap has two side walls extending radially away from each other in the circumferential direction, and a connecting part connecting one end in the radial direction, and both ends in the vertical direction and the other end in the radial direction are opened. The plurality of caps accommodate at least a portion of the joining portion at one end in the radial direction of the plurality of joining portions at least at a portion of the joining portion at the other end in the radial direction at a plurality of positions in the circumferential direction of the coil end. A rotating electric machine stator to which a resin is adhered is described.

Patent Document 4 (Japanese Patent Application Laid-Open No. 2014-50207) has a stator core in which a plurality of slots arranged in a circumferential direction are formed, and a stator coil inserted into the slots of the stator core. In a rotating electric machine including a stator and a rotor 150 rotatably disposed with a gap with respect to the stator core, the stator coil has a substantially U-shaped conductor having a rectangular cross section. A plurality of segment coils comprising a plurality of segment coils connected to each other, the segment coil has a connection portion connected to another segment coil at an end, and the rotating portion has a connection portion having a corner portion. ing.

JP 2011-54263 A International Publication 2013/99001 JP 2016-93027 A JP 2014-50207 A

回転 In this type of rotating electric machine, the formed segment coil is welded at the coil end to form a stator coil. However, the welded portion of the segment coil expands due to heat and generates stress due to a temperature change. Therefore, there is a problem that the welded portion of the segment coil is broken, the coil is disconnected, and the operation of the rotating electric machine becomes incomplete.

In order to solve the above-mentioned problems, for example, the configuration described in the claims is adopted. The present application includes a plurality of means for solving the above-described problems. For example, a stator for a rotating electric machine, in which a plurality of slots that are opened in the radial direction are formed in the circumferential direction, is provided. An iron core; and a plurality of segment coils arranged in the slot in a radial direction of the stator. Each of the plurality of segment coils includes an end portion of each of the plurality of segment coils exposed to the outside of the slot. A plurality of welds that connect adjacent segment coils, and an insulating covering portion that covers the plurality of welds and connects the welds in a radial direction of the stator. At least one of the welded portions has a protruding portion that protrudes from the side surface of the segment coil to the radially inner side or outer side.

According to the present invention, the rigidity of the weld can be improved. Problems, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

FIG. 1 is a schematic diagram illustrating an entire configuration of a rotating electric machine according to an embodiment of the present invention. It is a perspective view showing the stator of the rotary electric machine concerning the embodiment of the present invention. It is a perspective view of a stator core. It is a perspective view of the coil end after welding. It is a side view of the coil end after welding. It is a top view of the coil end after welding. It is a perspective view of the coil end after bridge | crosslinking part formation. It is sectional drawing of the coil end after formation of a bridge part. It is a figure which shows the welding direction of a segment coil. It is a figure which shows the welding direction of a segment coil. It is a side view of the coil end after welding. It is a figure which shows the welding method which uses a jig. It is a figure showing another welding method.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Overall configuration of rotating electric machine)
The rotating electric machine according to the present embodiment is a rotating electric machine suitable for use in running an automobile. Here, a so-called electric vehicle using a rotating electric machine includes a hybrid electric vehicle (HEV) having both an engine and a rotating electric machine, and a pure electric vehicle (EV) running only on the rotating electric machine without using an engine. However, the rotating electric machine described below can be used for both types.

FIG. 1 is a schematic diagram showing the entire configuration of a rotating electric machine 100 according to an embodiment of the present invention. FIG. 1 shows the inside of the rotating electric machine 100 with a part of the rotating electric machine 100 being a cross section. The rotating electric machine 100 is provided inside the case 10 and includes a housing 112, a stator 130 having a stator core 132 fixed to the housing 112, and a rotor 150 rotatably disposed in the stator 130. And The case 10 may be constituted by an engine case or a transmission case.

The rotating electric machine 100 is a three-phase synchronous motor with a built-in permanent magnet. In this embodiment, a three-phase synchronous motor will be described as an example of the rotating electric machine 100, but the present invention can be applied to an induction motor.

The rotating electric machine 100 according to the present embodiment operates as a motor for rotating the rotor 150 by supplying a three-phase alternating current to the stator coil 138 wound around the stator core 132. Also, when driven by the engine, the rotating electric machine 100 operates as a generator and outputs three-phase alternating current generated power. That is, the rotating electric machine 100 has both a function as an electric motor that generates a rotating torque based on electric energy and a function as a generator that generates electric power based on mechanical energy. Features can be used selectively.

The stator 130 is fixed to the housing 112. The stator 130 is fixed and held in the case 10 by fastening the flange 115 provided on the housing 112 to the case 10 with bolts 12. The rotor 150 fixed to the rotating shaft 118 is supported by

bearings

14A and 14B of the case 10, and is rotatably held inside the stator core 132.

FIG. 2 is a perspective view showing the stator 130 attached to the housing 112, and FIG. 3 is a perspective view of the stator core 132. The housing 112 is formed in a cylindrical shape by drawing a steel plate (such as a high-tensile steel plate) having a thickness of about 2 to 5 mm. A flange 115 is provided at one axial end of the housing 112, and is fixed to the case 10 with bolts as described above (see FIG. 1). The flange 115 is formed integrally with the housing 112 by drawing. Note that the stator 130 may be directly fixed to the case 10 without providing the housing 112.

The stator 130 is fixed to the inner peripheral side of the housing 112 and has a cylindrical stator core 132 and a stator coil 138 mounted on the stator core 132. The stator core 132 is formed, for example, by laminating a plurality of electromagnetic steel sheets 133 having a thickness of about 0.05 to 1.0 mm and formed by punching or etching. The laminated electromagnetic steel plates 133 are connected and fixed by welding, and the deformation of the electromagnetic steel plates 133 caused by the tightening force when pressed into the housing 112 is suppressed.

A plurality of slots 420 extending in the axial direction are formed at equal intervals in the circumferential direction in the stator core 132. The number of slots 420 is, for example, 72 in the present embodiment. The slots 420 accommodate the stator coils 138 as shown in FIG. In the example shown in FIG. 3, the slot 420 is an open slot, and an opening is formed on the inner peripheral side of the stator core 132. The width of the opening in the circumferential direction is preferably substantially equal to or slightly smaller than the coil mounting portion of each slot 420 in which the stator coil 138 is mounted.

絶縁 In each slot 420, an insulating paper (so-called slot liner) 300 is arranged. The insulating paper 300 is, for example, an insulating sheet of heat-resistant polyamide paper, and has a thickness of about 0.1 to 0.5 mm. The insulating paper 300 is provided in the slot 420 and the coil ends 140a and 140b. By disposing the insulating paper 300 in the slot 420, the insulating paper 300 is disposed between the coils inserted into the slot 420, and between the coil and the inner surface of the slot 420. The withstand voltage during the period has been improved.

The stator coil 138 is formed by connecting a plurality of U-shaped segment coils 28 (see FIGS. 4 and 7) to each other. The segment coil 28 is arranged such that one end thereof is adjacent to another segment coil 28 so that the end thereof is exposed from the slot 420 (that is, the stator 130), and the other end is formed of another segment coil. It is arranged adjacent to the coil 28. The segment coils 28 having adjacent ends are connected to each other at adjacent ends to form a stator coil 138 wound around the stator core 132.

The insulating paper 300 provided on the coil ends 140a and 140b is annularly provided between the coils for inter-phase insulation and inter-conductor insulation at the coil ends 140a and 140b. As described above, in the rotating electric machine 100 of the present embodiment, since the insulating paper 300 is provided inside the slot 420 and on the coil ends 140a and 140b, even if the insulating film 600 of the coil is damaged or deteriorated, The required withstand voltage can be maintained.

The teeth 430 are formed between the slots 420, and each tooth 430 is formed integrally with the annular core back 440. The stator core 132 is an integrated core in which the teeth 430 and the core back 440 are integrally formed. The teeth 430 guide the rotating magnetic field generated by the stator coil 138 to the rotor 150 and cause the rotor 150 to generate a rotating torque.

Rotor 150 has rotor core 152 and permanent magnet 154 held in a magnet insertion hole formed in rotor core 152.

A rectangular parallelepiped magnet insertion hole is formed in the rotor core 152 at regular intervals in the circumferential direction near the outer peripheral portion. A permanent magnet 154 is embedded in each magnet insertion hole and fixed with an adhesive or the like. The circumferential width of the magnet insertion hole is formed larger than the circumferential width of the permanent magnet 154, and magnetic gaps 156 are formed on both sides of the permanent magnet 154. The magnetic gap 156 may be filled with an adhesive or may be solidified with the permanent magnet 154 with resin.

The permanent magnet 154 forms the field pole of the rotor 150. In the present embodiment, one magnetic pole is formed by one permanent magnet 154, but one magnetic pole may be formed by a plurality of permanent magnets. By increasing the number of permanent magnets for forming each magnetic pole to a plurality, the magnetic flux density of each magnetic pole generated by the permanent magnet increases, and the magnet torque can be increased. As the permanent magnet 154, a neodymium-based or samarium-based sintered magnet, a ferrite magnet, a neodymium-based bonded magnet, or the like can be used. Desirably, a neodymium magnet is more suitable. An auxiliary magnetic pole may be formed between each permanent magnet 154.

(4) When a rotating magnetic field is generated in the stator 130 by supplying the three-phase alternating current to the stator coil 138, the rotating magnetic field acts on the permanent magnet 154 of the rotor 150 to generate a magnet torque. Since the above-described reluctance torque is generated in the rotor 150 in addition to the magnet torque, both the above-described magnet torque and reluctance torque act as the rotation torque on the rotor 150, and a large rotation torque is generated. Obtainable.

4, 5, 6, 7 and 8 are views showing the coil end 140b. FIG. 4 is a perspective view of the coil end 140b after welding, FIG. 5 is a side view after welding, and FIG. FIG. 7 is a plan view of the coil end 140b viewed from the end face direction, FIG. 7 is a perspective view after the bridge 40 is formed, and FIG. 8 is a side view after the bridge 40 is formed.

In this embodiment, eight segment coils 28 are arranged in each slot 420. As shown in FIG. 4, the ends of two adjacent segment coils 28 are welded and connected, and the coil end 140b is It is configured. For example, the base material of the copper wire forming the segment coil 28 is melted by arc welding such as TIG (Tungsten Inert Gas) welding, plasma welding, laser welding, or the like to form a welded portion 30, and the end of the segment coil 28 is formed. Connect.

凹部 The welded portion 30 is provided with a concave portion 32 on a radial side surface of the segment coil 28 on a surface perpendicular to the rotating shaft 118. The ends of the adjacent segment coils 28 are arranged such that a gap 29 is provided by the thickness of the coating or the insulating paper 300, and a recess 32 is provided at the position of the gap 29. In other words, as shown in FIG. 6, the welding portion 30 includes a first welding portion 34A formed at an end of the first segment coil 28, and a second segment coil disposed adjacent to the first segment coil 28. And a second welded portion 34B formed at an end of the stator 28, and a recess 32 having a smaller width in the radial direction of the stator 130 than at least one of the first welded portion 34A and the second welded portion 34B is formed. A third welded portion 34C is provided between the first welded portion 34A and the second welded portion 34B. By providing the recessed portion 32 in the welded portion 30 in this manner, the surface area of the welded portion 30 is increased, the area where the coil contacts the cooling oil is increased, and the cooling effect by the cooling oil can be improved.

Further, since the heating state of the copper surface solidified after melting in the welding portion 30 changes with the movement of the welding electrode 50, the color of the surface of the welding portion 30 is not uniform as shown in FIG. There is no gradation. As described above, the surface of the welded portion 30 becomes gradation, so that light reflection can be suppressed from a single color having metallic luster, and the protrusion 31 can be easily detected by image recognition. The side where wrinkles 33 described later are formed has a dark color, and the side where the wrinkles 33 are not formed has a bright color.

As shown in FIG. 5, the welded portion 30 has a protruding portion 31 that protrudes from the side surface of the segment coil 28 in one of the radial directions (the outer circumferential direction or the inner circumferential direction) of the stator 130. That is, the projecting portion 31 is provided on the welding portion 30 such that the center of gravity of the plurality of segment coils 28 to be connected before welding differs from the position of the center of gravity of the projecting portion 31.

By providing the projecting portion 31 projecting in the radial direction in the welded portion 30, the distance between the adjacent segment coils 28 can be kept constant, and the insulation performance of the coil deteriorates due to the variation in the shape and size of the welded portion 30. Can be suppressed.

Further, by forming the projecting portion 31 into a fixed shape and size, the distance between the adjacent welding portions 30 becomes constant, and the supply amount of the synthetic resin material for forming the bridging portion 40 described later is reduced. There is no need to control by the distance between the 30, and the bridge portion 40 can be formed easily and reliably.

As shown in FIG. 9, the welding of the coil is performed by moving the welding electrode 50 to which the voltage is applied from the inner peripheral side to the outer peripheral side to melt the copper of the coil end 140b and move the molten copper. The protruding portion 31 is formed by solidifying while being pulled by 50. The shape and size of the formed protrusion 31 can be controlled by controlling the moving speed and current (temperature) of the welding electrode 50.

The movement of the welding electrode 50 may be, for example, only one direction from the inner circumference to the outer circumference, and the ends of the segment coils 28 may be sequentially welded from the inner circumference to the outer circumference. By doing so, all the protruding portions 31 are formed so as to protrude in the outer peripheral direction, and a clearance when inserting the rotor 150 into the stator 130 can be secured.

The movement of the welding electrode 50 during welding may be changed alternately for each row as shown in FIG. In this way, in the welded portion 30, the first welding row (row 1, row 3) whose center of gravity is formed toward the inner peripheral side and the second welding row (row 3) formed toward the outer peripheral side are formed. Column 2) is formed. Thus, by making the direction of movement of the welding electrode 50 different for each row, it is necessary to move the welding electrode 50 from the outer peripheral side to the initial position on the inner peripheral side or from the inner peripheral side to the initial position on the outer peripheral side. And welding can be performed efficiently, and the time required for welding can be reduced.

皺 Further, as shown in FIG. 10, wrinkles 33 extending in the circumferential direction of the stator 130 are formed in the welding portion 30 on the moving direction side of the welding electrode 50 during welding. A plurality of wrinkles 33 are preferably formed in the radial direction of the stator 130. Due to the wrinkles 33, the surface area of the welded portion 30, that is, the area where the end of the segment coil 28 comes into contact with the cooling oil increases, and the cooling effect by the cooling oil can be improved.

In the present embodiment, the wire rods of the adjacent segment coils 28 are arranged in parallel, and a gap 29 is provided between the copper of the base material at the coil end by the thickness of the coating or the insulating paper 300, The welding portion 30 of the present embodiment moves so that the welding electrode 50 moves over the gap 29 together with the molten copper, and the welding portion 30 in which the molten copper is solidified is also formed on the gap 29. In the conventional method of welding without moving the welding electrode 50, the segment coil 28 is bent so that the ends come into contact with each other (see, for example, FIG. 13 of Patent Document 4 and JP-A-2014-50207). In this embodiment, as shown in FIG. 9, by employing a welding method in which the welding electrode 50 is moved in the radial direction of the stator 130, the segment coil 28 can be moved without contacting the ends of the segment coil 28. Can be reliably connected by welding. Further, since there is no need to bend the segment coil 28, adjacent coils do not come close to each other, so that appropriate insulation can be maintained.

7) After connecting the segment coils 28 by welding, the coil end 140b performs coating so as to connect the plurality of welded portions 30 to form the bridge portions 40, as shown in FIGS. In FIG. 8, the inside of the bridging portion 40 is shown so that the structure of the bridging portion 40 can be easily understood. The bridge portion 40 forms a coating of a synthetic resin in the radial direction of the stator 130 such that the coil ends 140b of the coils in the same slot 420 are integrated. For example, the crosslinked portion 40 may be formed by powder coating. Alternatively, the crosslinked portion 40 may be formed by applying an insulating varnish. Further, the bridging portion 40 may be constituted by an insulating tube or an insulating cap. By forming the bridging portion 40 functioning as an insulating coating covering the welded portion 30 so as to connect the adjacent welded portions 30 in the radial direction, the stress generated in the welded portion 30 can be dispersed, and the temperature change of the welded portion 30 Deformation and breakage (for example, breakage of the coil) can be suppressed.

When the protrusions 31 are provided in the welded portion 30 as described above, the interval between the welded portions 30 can be made constant, the supply amount of the synthetic resin material for forming the bridged portion 40 becomes constant, and the formation of the bridged portion 40 can be achieved. However, the bridging portion 40 may be formed without providing the protruding portion 31 in the welding portion 30.

セグメント Because the segment coils 28 arranged in the adjacent slots 420 are close to each other on the inner peripheral side, the bridge portion 40 may be connected in the circumferential direction on the inner peripheral side of the stator 130. For this reason, all the welds 30 are integrally connected in a spoke shape, and the strength of the welds 30 can be further improved, and the occurrence of cracks and the like can be prevented.

Cooling oil flows around the welded portion 30, and flows from the outer peripheral side to the inner peripheral side (or from the inner peripheral side to the outer peripheral side) along the bridge portion 40, and the cooling oil flows through the welded portion 30. The cooling effect can be improved without escaping at the cut. In particular, when the bridge portion 40 is formed so as to be coupled to the stator core 132, the cooling oil flowing along the bridge portion 40 does not flow into the stator core 132, and the welded portion 30 can be reliably cooled. .

As shown in FIG. 5, the protrusions 31 may be provided in all the welds 30 of the coils arranged in the same slot 420 (that is, the coil ends are arranged in the radial direction of the stator 130), but some of the protrusions 31 may be provided. It may be provided only in the welding portion 30. For example, the protruding portion 31 may be provided on the welded portion 30 excluding both ends. That is, as shown in FIG. 11, the inner weld portion 30A provided on the innermost periphery of the stator and the outer weld portion 30D provided on the outermost periphery are not provided with the protruding portion 31, and the inner weld portion 30A and the outer weld portion 30A are not provided. The projecting portion 31 may be provided in the middle welded

portions

30B and 30C between the portion 30D. The inner welding portion 30A provided on the innermost periphery of the stator and the outer welding portion 30D provided on the outermost periphery are provided with a projecting portion 31 having a small amount of projection, and the inner welding portion 30A and the outer welding portion 30D A projecting portion 31 having a large projecting amount may be provided between the middle welded

portions

30B and 30C.

When the welding electrode 50 moves in the radial direction of the stator 130, the moving speed and heat conditions of the welding electrode 50 may change at the positions of the welded portions 30 on both the inner and outer circumferential sides, and the projecting portion 31 may vary in shape and size. In such a case, as shown in FIG. 11, a protrusion 31 may be provided on the welded portion 30 of the coil except for both ends, which is arranged in the radial direction of the stator 130. By not providing the projecting portion 31 projecting to the inner peripheral side in the innermost welded portion 30, a clearance for inserting the rotor 150 into the stator 130 can be secured.

As shown in FIG. 12, when the welding electrode 50 moves in the radial direction of the stator 130, the

jigs

60A and 60B are provided on the inner peripheral side and the outer peripheral side of the coil, so that the inner peripheral side and the outer peripheral side are provided. The moving speed and the heat condition of the welding electrode 50 can be made the same at the welding portions 30 at both ends on the side as well as at the welding portions 30 at the other ends. The

jigs

60A and 60B may be made of the same material as the end of the segment coil 28 and may be melted similarly to the end of the coil segment 28, and preferably have the same heat capacity. For this reason, at the positions of the welded portions 30 at both ends on the inner peripheral side and the outer peripheral side, the protrusions 31 having the same shape can be formed in all the welded portions 30 without changing the speed and heat conditions of the welding electrode 50.

Note that the

jigs

60A and 60B may be disposed on both the inner peripheral side and the outer peripheral side, or may be disposed on one side. Particularly, since the segment coil 28 is close to the stator core 132 on the outer peripheral side, The contact between the coil and the stator core 132 may be suppressed by suppressing the amount of protrusion of the protrusion 31 of the outermost welded portion 30 (or without forming the protrusion 31).

As shown in FIG. 13, three or more segment coils 28 can be connected by welding. In the figure, four coil ends 140b of the coils 1 to 4 are connected by welding, and four coil ends 140b of the coils 5 to 8 are connected by welding. In the welding method of the present embodiment in which the welding electrode 50 is moved in the radial direction of the stator 130 near the end of the segment coil 28, by adjusting the interval at which the coils to be connected by welding are arranged, The above segment coils 28 can be connected.

For example, the segment coils 28 arranged at an interval of a half of the length of the projecting portion 31 projecting in the radial direction are connected to the adjacent segment coil 28 by the projecting portion 31. On the other hand, the segment coils 28 arranged at intervals of twice the length of the projecting portion 31 projecting in the radial direction are not connected to the adjacent segment coils 28, and the insulation determined by the distance is maintained. .

Next, a method for manufacturing the stator of this embodiment will be described. Before the welding step, the segment coils 28 are arranged in the slots 420 (first step).

As shown in FIG. 9, the welding of the coil moves the welding electrode 50 to which the voltage is applied from the inner peripheral side to the outer peripheral side to melt the copper at the end of the segment coil 28, and the molten copper moves. The protruding portion 31 is formed by solidifying while being pulled by the welding electrode 50 (second step). By controlling the moving speed and the current (temperature) of the welding electrode 50, the shape and size of the formed protrusion 31 can be controlled. As the shield gas, argon, helium, a mixed gas of argon and helium, or the like may be used.

移動 The movement of the welding electrode 50 may be, for example, only one direction from the inner peripheral side to the outer peripheral side. Further, the movement direction of the welding electrode 50 may be changed alternately for each row as shown in FIG. Specifically, in row 1, a first row welding step of moving and welding the welding electrode 50 from the outer peripheral side to the inner peripheral side is performed. Next, in the row 2 adjacent to the row 1, a second row welding process is performed in which the welding electrode 50 is moved from the inner circumference side, which is the opposite direction, to the outer circumference side to perform welding. Next, in the row 3 adjacent to the row 2, a first row welding step is performed in which the welding electrode 50 is moved and welded from the outer peripheral side to the inner peripheral side, which is the opposite direction. For this reason, the projection 31 formed on the welded portion 30 in the first row welding process and the projection 31 formed on the welded portion 30 in the second row welding process are opposite in the radial direction of the stator 130. It is formed to protrude. Thus, by making the direction of movement of the welding electrode 50 different for each row, it is necessary to move the welding electrode 50 from the outer peripheral side to the initial position on the inner peripheral side or from the inner peripheral side to the initial position on the outer peripheral side. And welding can be performed efficiently, and the time required for welding can be reduced.

7) After connecting the segment coils 28 by welding, as shown in FIGS. 7 and 8, coating is performed so as to connect the plurality of welded portions 30 to form the bridge portions 40 (third step). Specifically, the bridge portion 40 is formed by forming a coating of a synthetic resin in the radial direction of the stator 130 such that the coil ends 140b of the coils of the same slot 420 are integrated. For example, the crosslinked portion 40 may be formed by powder coating. Alternatively, the crosslinked portion 40 may be formed by applying an insulating varnish. Further, the bridging portion 40 may be constituted by an insulating tube or an insulating cap.

As shown in FIG. 12, at the time of welding using the

jigs

60A and 60B, the welding electrode 50 is positioned on the opposite side of the coil from the start position, which is the position of the jig 60A on the inner or outer circumference side of the coil. It moves to the end position which is the position of the tool 60B. By providing the

jigs

60A and 60B, the moving speed and the heat condition of the welding electrode 50 can be made the same at the welded portions 30 at both ends on the inner peripheral side and the outer peripheral side as with the welded sections 30 at the other ends. The

jigs

60A and 60B may be made of the same material as the end of the segment coil 28, and preferably have the same heat capacity.

By providing the jigs 60 </ b> A and 60 </ b> B, the speed and heat conditions of the welding electrode 50 do not change at the positions of the welding portions 30 at both ends on the inner peripheral side and the outer peripheral side. 31 can be formed.

The above description is merely an example, and the interpretation of the invention is not limited or restricted by the correspondence between the items described in the above embodiment and the items described in the claims. For example, in the above-described embodiment, a rotating electric machine having a permanent magnet in the rotor has been described as an example, but the present invention can be similarly applied to a stator of a rotating electric machine such as an induction motor. Further, the present invention can be applied to other than a rotating electric machine for driving a vehicle. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of one embodiment can be added to the configuration of another embodiment. .

The present invention is not limited to the embodiments described above, but includes various modifications and equivalent configurations within the spirit of the appended claims. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and the present invention is not necessarily limited to those having all the configurations described above. Further, a part of the configuration of one embodiment may be replaced with the configuration of another embodiment. Further, the configuration of one embodiment may be added to the configuration of another embodiment. Further, for a part of the configuration of each embodiment, another configuration may be added, deleted, or replaced.

28: segment coil 29:

gap

30, 30A, 30B, 30C, 30D: welded portion 31: projecting portion 32: concave portion 33: wrinkle 34A: first welded portion 34B: second welded portion 34C: third welded portion 40: bridge Unit 100: rotating electric machine 130: stator 132:

stator cores

140a, 140b: coil end 150: rotor 420: slot

Claims

A stator for a rotating electric machine,
A stator core in which a plurality of radially opened slots are formed in a line in the circumferential direction;
A plurality of segment coils arranged in the slot in the radial direction of the stator,
In the plurality of segment coils,
A plurality of welds formed at each end of the plurality of segment coils exposed to the outside of the slot and connecting adjacent segment coils,
And covering the plurality of welds, and having an insulating covering portion connecting the welds in a radial direction of the stator.
A stator for a rotating electric machine, wherein at least one of the plurality of welded portions has a protruding portion that protrudes from the side surface of the segment coil to the radially inner or outer circumferential side.
It is a stator of the rotating electric machine according to claim 1, wherein
Each of the plurality of welds connects a first segment coil and a second segment coil arranged adjacent to each other,
Before the welding portion is formed, the first segment coil and the second segment coil such that a gap is provided between an end of the first segment coil and an end of the second segment coil. Is a stator of the rotating electric machine arranged in the slot.
It is a stator of the rotating electric machine according to claim 1, wherein
When viewed from the axial direction,
Each of the plurality of welds is
Connecting the first segment coil and the second segment coil arranged adjacent to each other,
A first weld formed at an end of the first segment coil; and a second weld formed at an end of the second segment coil,
A third welded portion in which a concave portion having a narrower circumferential width of the stator is formed than at least one of the first welded portion and the second welded portion is located between the first welded portion and the second welded portion. The stator of the rotating electric machine provided in.
It is a stator of the rotating electric machine according to claim 1, wherein
A stator for a rotating electrical machine, wherein a plurality of wrinkles extending in a circumferential direction of the stator are formed in each of the plurality of welds.
It is a stator of the rotating electric machine according to claim 1, wherein
The plurality of welds,
A first welding row in which the position of the center of gravity of the welded portion is shifted toward the inner peripheral side,
A second welding row in which the position of the center of gravity of the welded portion is shifted toward the outer peripheral side.
It is a stator of the rotating electric machine according to claim 1, wherein
The plurality of welds are an outer weld provided on an outermost circumference of the stator, an inner weld provided on an innermost circumference of the stator, and provided between the outer weld and the inner weld. Including a welded portion,
The protrusion of the middle weld is larger than the protrusion of the outer weld or the protrusion of the inner weld, or a protrusion is provided in the middle weld, and the outer weld and the inner weld are provided with a protrusion. Is a stator of a rotating electric machine having no protrusion.
A method for manufacturing a stator of a rotating electric machine,
A first step of arranging a plurality of segment coils in a plurality of slots formed in a stator core in a radial direction of the stator;
A second step of sequentially welding each end of the plurality of segment coils exposed to the outside of the slot to form a weld by moving a welding electrode,
In the second step, at least one of the plurality of welds is formed with a protruding portion that protrudes from the side surface of the segment coil from the radially inner circumferential side toward the outer circumferential side or from the outer circumferential side toward the inner circumferential side. Manufacturing method.
It is a manufacturing method of the stator of Claim 7, Comprising:
And a third step of covering the plurality of welds and forming an insulating coating connecting the welds in a radial direction of the stator.
It is a manufacturing method of Claim 7, Comprising:
The second step includes:
A first row welding step of moving the welding electrode from the inner peripheral side to the outer peripheral side, melting the ends of the plurality of segment coils in order, and connecting adjacent segment coils;
Moving the welding electrode from the outer peripheral side to the inner peripheral side, melting the ends of the plurality of segment coils in order, and connecting the adjacent segment coils in a second row welding step,
A manufacturing method in which a projection formed in the first row welding step and a projection formed in the second row welding step are formed to project in opposite directions in a radial direction of the stator.
It is a manufacturing method of Claim 7, Comprising:
The plurality of welds are an outer weld provided on an outermost circumference of the stator, an inner weld provided on an innermost circumference of the stator, and provided between the outer weld and the inner weld. Including a welded portion,
In the second step, the protrusion of the middle weld is larger than the protrusion of the outer weld or the protrusion of the inner weld, or the middle weld is provided with a protrusion, And a method of forming the projecting portion such that the projecting portion is not provided in the inner welded portion.
It is a manufacturing method of Claim 7, Comprising:
A step of disposing a jig that melts similarly to the segment coils is provided on at least one of the inner peripheral side and the outer peripheral side of the plurality of segment coils arranged in the radial direction of the stator before the first step,
The method according to claim 1, wherein in the first step, welding is started from the position of the jig and / or is ended at the position of the jig.