JP2020205721A - Stator and rotary electric machine including the same - Google Patents

Abstract

To reduce the manufacturing cost of a stator by manufacturing a stator coil using conductor segments of the same length.SOLUTION: A stator has a stator core 71 having a plurality of slots 71a arranged in an annular shape and a plurality of conductor segments 30 inserted radially side by side into each slot. An axial end of the conductor segment is joined to the axial end of another pair of conductor segments at a joint 32a. The conductor segment is bent in an arc shape from an end of a slot toward the joint. The lengths of the arcs seen from the axial direction of the paired conductor segments are the same.SELECTED DRAWING: Figure 13

Description

The present application relates to a stator, a rotary electric machine provided with the stator, and a method for manufacturing the stator.

In recent years, in order to reduce the environmental load on automobiles, there have been increasing demands for lowering the idling speed to reduce fuel consumption, reducing the weight to improve fuel efficiency, and narrowing the engine room to secure the space inside the vehicle. ing. In response to such demands, in-vehicle rotary electric machines are required to be smaller and have higher output. As a compact and high-power rotary electric machine, a stator coil is formed by inserting a plurality of conductor segments into the slots of a stator core and joining the conductor segments protruding from different slots at a joint to form a stator coil. There is a rotary electric machine that has achieved a high space factor and a low resistance.

For example, as a stator of a conventional rotary electric machine, a plurality of straight conductor segments having different lengths are inserted into one slot, and a conductor segment protruding from the slot is twisted and bent to be inserted into another slot. A stator coil joined to a segment has been disclosed (see, for example, Patent Document 1).

Japanese Patent No. 4475108

However, if conductor segments having different lengths are used, the manufacturing cost of the conductor segments is high, so that there is a problem that the manufacturing cost of the stator is high.

The present application has been made to solve the above-mentioned problems, and an object of the present application is to suppress the manufacturing cost of the stator by manufacturing the stator coil using conductor segments having the same length.

The stator according to the present application has a stator core having a plurality of slots arranged in an annular shape and a plurality of conductor segments inserted in each slot in a radial direction, and an axial end portion of the conductor segment. Is joined to the axial end of the other pair of conductor segments at the joint, and the conductor segment is bent in an arc shape from the end of the slot toward the joint to form a pair of conductor segments. The lengths of the arcs seen from the axial direction of each other are the same.

In the stator of the present application, the conductor segments are bent in an arc shape from the end of the slot toward the joint, and the lengths of the arcs of the paired conductor segments viewed from the axial direction are the same. Stator coils can be manufactured using conductor segments of the same length. As a result, the manufacturing cost of the stator can be suppressed.

It is sectional drawing which shows the structure of the rotary electric machine which concerns on Embodiment 1. FIG. It is a perspective view which shows the stator of Embodiment 1. FIG. It is a top view which saw the stator of Embodiment 1 from the axial direction. It is a side view of the stator of Embodiment 1. FIG. It is a perspective view of the ordinary conductor segment of Embodiment 1. FIG. It is a flowchart which shows the manufacturing process of the rotary electric machine which concerns on Embodiment 1. It is a top view of the conductor segment of Embodiment 1. FIG. It is sectional drawing of the conductor segment holding jig of Embodiment 1. FIG. It is a top view which showed the twist locus of the conductor segment of Embodiment 1. FIG. It is a perspective view which shows the joint part of the ordinary conductor segment of Embodiment 1. FIG. It is a side view of the stator of Embodiment 1. FIG. It is sectional drawing of the stator of Embodiment 1. FIG. It is a top view of the stator of Embodiment 1. It is a perspective view which shows the end part of the normal conductor segment and the lead conductor segment of Embodiment 1. FIG. It is sectional drawing of the joint part of the conductor segment of Embodiment 1. FIG. It is a top view which saw the stator of Embodiment 1 from the axial direction.

Hereinafter, the stator and the rotary electric machine according to the embodiment for carrying out the present application will be described in detail with reference to the drawings. In each figure, the same reference numerals indicate the same or corresponding parts.

Embodiment 1.
FIG. 1 is a cross-sectional view showing the configuration of the rotary electric machine according to the first embodiment. The rotary electric machine of the present embodiment is, for example, an alternator for a vehicle. In this rotary electric machine 1, a Randall-shaped rotor 2 is rotatably mounted in a housing 5 composed of an aluminum front bracket 3 and a rear bracket 4 via a shaft 6, and a cylindrical stator 7 rotates. It is configured to be fixed to the inner wall surface of the housing 5 so as to cover the outer peripheral side of the child 2. That is, the rotor 2 is rotatably provided on the inner diameter side of the cylindrical stator 7 with respect to the stator 7. The stator 7 is composed of a stator core 71 and a stator coil 72 inserted into the slot of the stator core 71. The shaft 6 is rotatably supported by the front bracket 3 and the rear bracket 4. A pulley 8 is fixed to one end of the shaft 6 so that the rotational torque of the engine can be transmitted to the shaft 6 via a belt (not shown) stretched on the pulley 8. A slip ring 9 that supplies an electric current to the rotor 2 is fixed to the other end of the shaft 6, and a pair of brushes 10 are housed in a brush holder 11 installed in the housing 5 so as to be in sliding contact with the slip ring 9. There is. A regulator 12 for adjusting the magnitude of the AC voltage generated by the stator 7 is adhered to a heat sink 13 fitted to the brush holder 11. A rectifier 14 that is electrically connected to the stator coil 72 and rectifies the alternating current generated by the stator coil 72 to direct current is mounted in the housing 5.

The rotor 2 includes a rotor coil 21 through which an electric current is passed to generate a magnetic flux, and a pair of pole cores 22 provided so as to cover the rotor coil 21 and having magnetic poles formed by the magnetic flux generated by the rotor coil 21. It is composed of 23. The pair of pole cores 22 and 23 are made of iron, and eight claw-shaped claw-shaped magnetic poles 24 and 25 are projected from the outer peripheral edge at equal pitches in the circumferential direction and face each other so as to engage the claw-shaped magnetic poles 24 and 25. Is fixed to the shaft 6. Further, cooling fans 15 are fixed to both ends of the rotor 2 in the axial direction. Further, the housing 5 is provided with intake holes 3a and 4a on the axial end faces of the front bracket 3 and the rear bracket 4, respectively. Further, the housing 5 is provided with exhaust holes 3b and 4b on both outer and shoulder portions of the front bracket 3 and the rear bracket 4 so as to face the outer sides of the stator coil 72 in the radial direction.

FIG. 2 is a perspective view showing the stator of the present embodiment. The stator 7 includes a cylindrical stator core 71 in which a plurality of slots 71a penetrating in the axial direction are formed in an annular shape at equal pitches, a stator coil 72 wound around the stator core 71, and the stator coil 72. An insulator 73 that is mounted in each slot 71a and electrically insulates the stator core 71 and the stator coil 72 is provided. The stator core 71 is made of laminated electromagnetic steel sheets, and includes a cylindrical core back 71b and a plurality of teeth 71c protruding toward the central axis on the inner peripheral side of the core back 71b. The space between the teeth 71c arranged in an annular shape is the slot 71a. As the insulator 73, a material of a polymer compound such as rubber or resin, or a material such as paper, mica, or glass fiber can be used.

FIG. 3 is a top view of the stator of the present embodiment as viewed from the axial direction. As shown in FIG. 3, the stator 7 includes a plurality of stator coils 72 arranged radially from the inner peripheral side to the outer peripheral side in each slot. Hereinafter, the inner peripheral side of the stator coil inserted in the same slot is referred to as the inner layer side, and the outer peripheral side is referred to as the outer layer side. Here, 96 slots are formed in the stator core 71 at equal intervals so as to accommodate two sets of three-phase stator coils described later according to the number of magnetic poles of the rotor.

FIG. 4 is a side view of the stator of the present embodiment. As shown in FIG. 4, the stator coil 72 is configured by joining a plurality of conductor segments 30 having a rectangular cross section at a joining portion 32a. The conductor segment 30 is joined at a joint portion 32a with another conductor segment that is folded out of the stator core 71 and inserted into slots separated by a predetermined number. At this time, the conductor segments on the inner layer side and the conductor segments on the outer layer side are alternately joined to form the stator coil 72. The plurality of conductor segments 30 include a first conductor segment having the same length (hereinafter referred to as a normal conductor segment) and a second conductor segment having a lead wire portion extended to one end of the normal conductor segment (hereinafter referred to as a normal conductor segment). , Lead conductor segment). For example, in the case of a rotary electric machine having 96 slots for accommodating two sets of three-phase stator coils, there are a total of 576 conductor segments 30, of which 552 are normal conductor segments 30a, and the rest. Twenty-four are lead conductor segments 30b. The lead conductor segment 30b is connected to an output terminal portion such as a rectifier by an extended lead wire portion, or the lead conductor segments 30b are joined to each other as a neutral point. Further, as shown in FIG. 4, the conductor segment 30a and the lead conductor segment 30b are usually formed in a portion exposed from the stator core 71 in order to join with other conductor segments or to prevent the conductor segments 30 from coming into contact with each other. It is twisted and slanted.

FIG. 5 is a perspective view of a normal conductor segment. FIG. 5 shows two normal conductor segments 30a. Normally, the conductor segment 30a has an axially linear insertion portion 31a inserted into the slot of the stator core and a coil end portion 31b bent in the circumferential direction from the insertion portion 31a and exposed to the outside of the stator core. It is composed of and. Two normal conductor segments 30a are joined by a joining portion 32a at the end of the coil end portion 31b of the normal conductor segment 30a. Although not shown, the lead conductor segment usually further includes a lead wire portion extending from one end of the coil end portion 31b of the conductor segment 30a. As shown in the enlarged view of the portions A, B, and C in FIG. 5, a chamfered portion 31c is provided at the end of each coil end portion 31b of the normal conductor segment 30a.

Next, the manufacturing process of the rotary electric machine of the present embodiment will be described. In the manufacturing process of the rotary electric machine of the present embodiment, the joint portion is formed by laser welding.
FIG. 6 is a flowchart showing a manufacturing process of the rotary electric machine. The manufacturing process of the rotary electric machine includes a conductor segment manufacturing step of manufacturing the rod-shaped conductor segment in step S1, a normal conductor segment inserting step of inserting a plurality of rod-shaped normal conductor segments into the conductor segment holding jig of step S2, and step S3. One end side twisting step of the normal conductor segment (hereinafter referred to as one end side) of the normal conductor segment, an insulator insertion step of inserting an insulator into the stator core in step S4, and the normal conductor segment of step S5. In the conductor segment assembly insertion step of inserting the conductor segment aggregate including the lead conductor segment into the stator core, the conductor segment twisting the other end (hereinafter referred to as the other end side) of the conductor segment aggregate in step S6. The other end twisting step of the aggregate, the conductor segment in step S7, the joint forming step of joining both ends of the aggregate to form a joint, and the lead conductor segment forming the lead wire of the lead conductor segment in step S8. The molding step, the neutral point joining step of joining the neutral points of step S9, the insulating treatment step of insulating the joined portion of step S10, and the conductor coil of step S11 impregnated with varnish to form the conductor coil. It is equipped with a varnish impregnation process for fixing to the stator core.

The outline of each process will be described below.
Conductor segment manufacturing process (step S1)
In this step, a copper wire wound around a bobbin with a circular cross section is pulled out to a linear length and cut, and the round copper wire is crushed into a flat shape to form a rod-shaped conductor segment with a rectangular cross section. Perform the processing. Since the copper wire wound around the bobbin has an insulating coating, the insulating coating at the end portion to be a joint is peeled off. Further, the end portion is plastically processed into a shape that is easy to weld. At this time, as shown in the enlarged view of the portions A, B, and C of FIG. 5, the end portion of the conductor segment is provided with a chamfered portion 31c by plastic working on the outer surface of the joint portion 32a. When a copper wire having a round cross section is crushed into a rectangular shape to form a rod-shaped conductor segment having a rectangular cross section, the conductor segment 30 is continuous from both ends to the center as shown in FIG. It is possible to provide two portions 34 in which the cross-sectional area is reduced and the cross-sectional area is minimized. The cross-sectional area of the conductor segment 30 continuously increases from the portion 34 having the smallest cross-sectional area toward the central portion. The portion 34 having the minimum cross-sectional area is set so that the conductor segment 30 is exposed from the end of the slot when the conductor segment 30 is inserted into the slot of the stator core. By using the conductor segment having such a shape, it is possible to soften the force applied to the conductor segment in the twisting process of the conductor segment described later. As a result, in the twisting process of the conductor segment, the possibility that the insulating coating of the conductor segment is damaged is reduced, and the dielectric strength of the conductor segment is improved.

Normal conductor segment insertion step (step S2)
In order to form the coil end portion of the conductor segment shown in FIG. 5, a rod-shaped conductor segment is inserted into a slot corresponding to the normal conductor segment of the conductor segment holding jig in the first twisting machine. At this time, a flat plate-shaped receiver is placed below the conductor segment holding jig so that the conductor segment does not fall off, and one end of all the conductor segments is exposed above the conductor segment holding jig. Hold at height.

FIG. 8 is a radial cross-sectional view showing a state in which a normal conductor segment 30a having a rod shape and the same length is inserted into the conductor segment holding jig 74. As shown in FIG. 8, all the normal conductor segments 30a are held at the same height by exposing the end portion on one end side above the conductor segment holding jig 74. Since the conductor segment holding jig 74 has a shape similar to that of the stator core 71, the stator core 71 can be used instead of the conductor segment holding jig 74, which will be described later.
When the stator core 71 is used instead of the conductor segment holding jig 74, the lead conductor segment can also be inserted into the stator core at the same time in this step. In that case, the conductor segment assembly insertion step (step S5) shown in FIG. 6 can be omitted.

One end side twisting step of the normal conductor segment (step S3)
In the first twisting machine, for the conductor segment exposed above the conductor segment holding jig and the end on one end side is held at the same height, the annular jig of the first twisting machine is used in the axial direction. Twist in the circumferential and radial directions while holding down. In this way, one end side of the conductor segment is usually twisted.
When the stator core into which the normal conductor segment and the lead conductor segment are inserted is prepared in step S2, the normal conductor segment and the lead conductor segment can be twisted at the same time in step S3. By changing the depth of the conductor segment insertion part so that the lead conductor segment can also be inserted into a part of the conductor segment insertion part of the ring jig in the first twister, the lead conductor segment can be inserted at the same time in addition to the normal conductor segment. It can be inserted into a ring jig. Then, as shown in FIG. 4, the normal conductor segment and the lead conductor segment can be twisted at the same time. In this case, the operation of twisting the lead conductor segment is the same as the operation of twisting the normal conductor segment except that the depth of the conductor segment insertion portion of the ring jig is different.

FIG. 9 is a top view showing the twisting locus of the conductor segment in the one end side twisting step of the normal conductor segment in step S3 and the other end side twisting step of the conductor segment assembly in step S6. The double-headed arrows shown in FIG. 9 represent the twisting loci of the normal conductor segments to be joined, and the lengths thereof are L11, L12, L13, and L14. The twist rotation angle is adjusted so that the twist lengths of the pair of conductor segments to be joined are the same, that is, L11 = L13 and L12 = L14. In other words, the conductor segments are bent in an arc shape from the end of the slot toward the joint, and the lengths of the arcs of the paired conductor segments viewed from the axial direction are the same. By using this method, conductor segments of the same length can be used, and equipment costs and processing costs can be suppressed. Further, by adjusting the rotation angle, the positions of the end portions of the conductor segments can be accurately aligned, which leads to reduction of welding defects.

Insulator insertion step (step S4)
Insert the insulator into the slot of the stator core. The outer diameter of the insulator on the opposite side to the insertion side is designed to be larger than the outer diameter of the slot so that the inserted insulator does not fall out of the slot.

Conductor segment assembly insertion step (step S5)
The normal conductor segment whose one end side is twisted in the one-side twisting step of the normal conductor segment in step S3 is separated from the conductor segment holding jig. At this time, the conductor segments are usually maintained in a state of being arranged in an annular shape. Separately, a lead conductor segment with one end twisted is prepared, and the lead conductor segment is inserted at a predetermined position between the normal conductor segments in which the annular arrangement is maintained, and the one end side is twisted. Form an aggregate of conductor segments. Finally, this conductor segment assembly is inserted into the stator core into which the insulator is inserted.
In the normal conductor segment insertion step of step S2, when the normal conductor segment and the lead conductor segment are simultaneously inserted into the stator core by using the stator core 71 instead of the conductor segment holding jig 74, this step is unnecessary. It can also be.

Twisting step on the other end side of the conductor segment assembly (step S6)
The stator core into which the conductor segment assembly is inserted is installed in the second twister so that the other end side faces upward. Place a receiver under the stator core that matches the shape of the conductor segment on one end that has been twisted, and expose the other ends of all conductor segments above the stator core to hold them at the same height. To do. In the second twisting machine, the conductor segment aggregate exposed above the stator core and held at the same height is held in the circumferential direction while being held in the axial direction by using the ring jig of the second twisting machine. And twist in the radial direction. In this way, the other end side of the conductor segment assembly is twisted. At this time, as shown in FIG. 9, when the length of the twist locus of the conductor segments to be joined is L11, L12, L13 and L14, the twist lengths of the pair of conductor segments to be joined are the same. That is, the twist rotation angle is adjusted so that L11 = L13 and L12 = L14. In other words, the conductor segments are bent in an arc shape from the end of the slot toward the joint, and the lengths of the arcs of the paired conductor segments viewed from the axial direction are the same.

Joint forming step (step S7)
In the conductor segment assembly in which both ends are twisted through the steps S1 to S6, both ends of the normal conductor segments to be joined are substantially free of gaps as shown in the A portion of FIG. It is in a state. The ends of the normally joined conductor segments to be joined are joined using a laser welder. FIG. 10 is a perspective view showing a joint portion of the conductor segment 30a. As shown in FIG. 10A, the insulating coating 31d is peeled off from the ends of the normally conductor segments 30a to be joined. Welding is performed by propagating laser light on both ends of the normal conductor segments 30a in the radial direction to form a joint portion 32a for joining the normal conductor segments 30a to each other, as shown in FIG. 10B. As shown in the enlarged view of A in FIG. 5, if the chamfered portion 31c is provided on the outside of the joint portion by plastic working, the heat diffusion becomes small during laser welding, and reduction of welding defects can be expected. ..

FIG. 11 is a side view of the stator manufactured through the steps S1 to S7. FIG. 11 is a side view of the stator in a state where the normal conductor segment 30a on which the joint is formed is inserted into the stator core, as viewed from the inner peripheral side. Note that FIG. 11 shows only two paired normal conductor segments for explanation. The normal conductor segment 30a protruding from the insulator 73 between the teeth 71c is twisted and bent in the circumferential direction, and is joined to another normal conductor segment 30a at a joint portion 32a at an axial end portion.

FIG. 12 is a cross-sectional view of the stator manufactured through the steps S1 to S7. FIG. 12 is a radial cross-sectional view of the stator in a state where the normal conductor segment 30a on which the joint is formed is inserted into the stator core 71. As shown in FIG. 12, the height of the joint portion 32a from the end of the slot is higher at the joint portion 32a of the normal conductor segment 30a inserted on the inner diameter side of the slot, and is inserted on the outer diameter side of the slot. The joint portion 32a of the normal conductor segment 30a is lower.

FIG. 13 is a top view of the stator manufactured through the steps S1 to S7. FIG. 13 is a top view of the stator in a state where the normal conductor segment 30a on which the joint is formed is inserted into the stator core 71 as viewed from the axial direction. Note that FIG. 13 shows only some normal conductor segments for the sake of explanation. As shown in FIG. 13, the normal conductor segment 30a is bent in an arc shape from the end portion of the slot 71a toward the joint portion 32a, and the length of the arc seen from the axial direction of the paired normal conductor segments 30a. Are the same.

Lead conductor segment molding step (step S8)
The lead wire portion of the lead conductor segment is formed so that the end portion of the lead conductor segment included in the conductor segment assembly can be connected to an output terminal portion such as a rectifier, or the lead conductor segments can be joined to each other as a neutral point.

Neutral point joining step (step S9)
The ends of the lead conductor segments formed so that they can be joined as neutral points in the lead conductor segment forming step of step S8 are joined using a laser welder.

Insulation treatment step (step S10)
The joint portion is formed by applying a powder of an insulating resin to the portion joined by using a laser welder in the joint portion forming step of step S7 and the neutral point joining step of step S9 by using powder coating. An insulating resin layer is formed on the surface of the surface and the surface of the neutral point.

Varnish impregnation step (step S11)
A varnish is impregnated into the slot of the stator core formed by joining the conductor segments at the joint to fix the stator coil to the stator core.

In this varnish impregnation step, as shown in FIG. 7, when the conductor segment is provided with two portions having the minimum cross-sectional area, the portion having the minimum cross-sectional area is the position where the conductor segment is exposed from the end of the slot. Therefore, there is a gap between the opening of the slot of the stator core and the conductor segment, which facilitates the injection of varnish into the slot. Further, since the surface of the conductor segment is inclined from the opening of the slot toward the central portion of the slot, the varnish can easily penetrate to the central portion along the inclined portion.

When the insulator is made of a material such as paper or glass fiber through which the varnish can pass, the varnish can be applied along the axial direction from the inner peripheral side of the stator core. At this time, the varnish penetrates into the slot from the inner peripheral surface of the stator core, and first reaches the conductor segment located on the innermost inner diameter side of the slot. When the conductor segment having the shape shown in FIG. 7 is used, the innermost conductor segment has a portion where the cross-sectional area is minimized at a position exposed from the stator core, and the surface of the conductor segment is inclined inside the slot. .. The varnish that reaches the innermost conductor segment moves to the outer diameter side along this inclination. That is, the wet area of the varnish is increased by using the conductor segment having the shape shown in FIG. 7. Therefore, the varnish can be applied along the axial direction from the inner peripheral side of the stator core, and the impregnation property of the varnish in the axial direction can be further improved. Further, by applying the varnish along the axial direction from the inner peripheral side of the stator core, the effect that the innermost conductor segment can be more reliably fixed by the varnish can be obtained.

Since the stator manufactured through the steps S1 to S11 is manufactured using rod-shaped conductor segments having the same length, the manufacturing cost of the stator can be suppressed. Further, since the rod-shaped conductor segment is inserted into one slot, the process of inserting the conductor segment is also simplified.

Further, since the conductor segments are bent in an arc shape from the end of the slot toward the joint portion and the lengths of the arcs of the paired conductor segments viewed from the axial direction are the same, the paired conductor segments Welding defects can be reduced because the joint surfaces of the above can be matched accurately.

Further, as shown in FIG. 12, in the stator of the present embodiment, the height of the joint portion 32a from the end of the slot is higher at the joint portion 32a of the conductor segment inserted on the inner diameter side of the slot. , Since the joint portion of the conductor segment inserted on the outer diameter side of the slot is lower, it is possible to avoid contact between the conductor segments of different layers. Even if the conductor segments of different layers come into contact with each other, the surface of the conductor segments is coated with an insulating coating, so that there is no short circuit. Further, in the stator of the present embodiment, the protruding heights of the ends of the conductor segments before being twisted are all the same, but as shown in FIG. 12, after being twisted, each layer is paired. The protruding heights of the ends of the conductor segments are different, and the protruding heights of the ends of the paired conductor segments of the same layer are the same. Therefore, the welding work in the joining process becomes easy.

Hereinafter, the main steps will be described in more detail.
Conductor segment manufacturing process (step S1)
As described above, there are roughly two types of conductor segments. One is a normal conductor segment that joins conductor segments to each other, and the other is a lead conductor segment. The lead conductor segment usually has a lead wire portion extended to one end of the conductor segment, and this lead wire portion is connected to an output terminal portion such as a rectifier, or is a lead conductor segment as a neutral point. They are joined together.

Usually, the conductor segment is a prismatic member formed by crushing a copper columnar member having an enamel insulating coating, and has peeling portions of the insulating coating by plastic working at both ends. Normally, the conductor segment is composed of an axially linear insertion portion that is inserted into the slot of the stator core and a coil end portion that is bent in the circumferential direction from this insertion portion and is exposed to the outside of the stator core. ing. The lead conductor segment has a prismatic shape in which the insertion portion and the coil end portion having the same shape as the normal conductor segment are formed by crushing a copper columnar member, and the lead wire portion extended from the coil end portion is a columnar shape. .. The lead conductor segment also has a peeling portion of the insulating coating at the end, and the insulating coating of enamel is applied to the outside except for the peeling portion.

As shown in the enlarged view of FIG. 5, chamfered portions 31c (also referred to as copper cutout portions) are usually provided at both ends or one end of the conductor segment and the lead conductor segment. The chamfered portion 31c is provided for the purpose of facilitating the insertion of the conductor segment into the insulator. The chamfered portion 31c facilitates insertion of the conductor segment into a conductor segment holding jig, a ring jig, or the like attached to the twisting machine when twisting. Further, the chamfered portion 31c has the same effect when attached to a jig for fixing the conductor segment in the joining process. Further, since the amount of the melted conductor segment is reduced when laser welding is performed by the chamfered portion 31c, there is an effect of preventing the melted conductor segment from spreading in the lateral direction and coming into contact with the adjacent conductor segment.

FIG. 14 is a perspective view showing the ends of the normal conductor segment and the lead conductor segment. FIG. 14A shows a chamfered portion 31c at the end of the lead conductor segment 30b. 14 (b) to 14 (e) usually show the chamfered portion 31c at the end of the conductor segment 30a. As shown in FIG. 14, in the normal conductor segment and the lead conductor segment, the chamfered portion 31c is formed by cutting out the side surface of the end portion in a shape such as a rectangular parallelepiped shape or a pyramid trapezoidal shape, and is cut toward the tip portion. The shape has a small area.

Normal conductor segment insertion step (step S2)
First, the conductor segment holding jig will be described. The conductor segment holding jig has a shape similar to that of a stator core, and has a cylindrical shape in which a plurality of slots extending in the axial direction are formed at equal pitches in the circumferential direction. The slot of the conductor segment holding jig has almost the same shape and pitch as the slot of the stator core. Below the conductor segment holding jig, a receiver for supporting the other end side of the conductor segment is usually provided. This receiver has a mechanism that can move up and down with respect to the conductor segment holding jig.

When inserting the normal conductor segment into the conductor segment holding jig, the rod-shaped normal conductor segments having the same length are inserted into the slots of the conductor segment holding jig in order from the end. At this time, four normal conductor segments from the first layer to the fourth layer are aligned and inserted in a row from the inner peripheral side to the outer peripheral side in the radial direction of the slot of the conductor segment holding jig. Here, the lead conductor segment is not inserted, and only the normal conductor segment is inserted. When the conductor segment is usually inserted into the conductor segment holding jig, it can be easily inserted into the slot because chamfered portions are provided at both ends of the conductor segment. Further, a stator core can be used instead of the conductor segment holding jig. When a stator core is used instead of the conductor segment holding jig, the lead conductor segment can be inserted at the same time as the normal conductor segment.

Conductor segment holding The conductor segment holding jig so that the length of the protruding portion of the normal conductor segment exposed from one surface in the axial direction of the conductor segment holding jig is longer than the length of the protruding portion of the normal conductor segment exposed from the other surface. Normally, the protrusion length of the conductor segment is adjusted by moving the jig installed below the jig up and down.

One end side twisting step of the normal conductor segment (step S3)
As shown in FIG. 4, it is necessary to twist both sides of the conductor segment 30, but first, a step of twisting one end side of the normal conductor segment inserted in the conductor segment holding jig will be described. In the first twisting machine, for the conductor segment exposed above the conductor segment holding jig and the end on one end side is held at the same height, the annular jig of the first twisting machine is used in the axial direction. Twist in the circumferential and radial directions while holding down. At this time, since the conductor segments adjacent to each other in the radial direction are twisted in the same slot in the direction in which they are separated from each other, the adjacent conductor segments do not come into contact with each other.

Further, the conductor segments inserted into the adjacent slots are twisted in the same direction, but do not come into contact with each other because a gap is formed in the height direction. Even if the conductor segments come into contact with each other, the surface is coated with enamel insulation except for the end portion, so that the conductor segments are not electrically short-circuited. In this way, one end side of the conductor segment is usually twisted.

The operation of the first twisting machine will be described in detail. The operation of the second twister in the step of twisting the other end side of the conductor segment assembly in step S6 is basically the same. In the following description of the operation of the first twisting machine, in the case of the second twisting machine, the conductor segment holding jig corresponds to the stator core.
The conductor segment holding jig in which the conductor segment is usually inserted into the slot is set in the conductor segment holding jig receiver. The conductor segment holding jig receiver, which is important for aligning the conductor segments before the twisting process, will be described.

The conductor segment holding jig receiver is provided with a mechanism capable of moving the conductor segment holding jig in the axial direction. This mechanism is important in determining the height of the conductor segment in the twisting process. First, the conductor segment holding jig is set in the conductor segment holding jig receiver of the first twisting machine. At this time, the conductor segment on the other end side exposed downward from the conductor segment holding jig is inserted so as to have a long protrusion in advance. At this time, the conductor segment on the other end side is supported from below by a flat jig. Then, the conductor segment holding jig receiver moves the conductor segment holding jig in the axial direction until the protrusion of the conductor segment on the other end side reaches a predetermined length, and is exposed upward from the conductor segment holding jig. Determine the length of the lead of the conductor segment on one end side. By regulating the length of the protrusion of the conductor segment on one end side with the conductor segment holding jig receiver in this way, the twisting process can be performed with high accuracy. Then, the outer peripheral portion of the conductor segment holding jig is fixed by the clamper. Further, by pressing the upper part of the conductor segment holding jig with the conductor segment holding jig holder, the vertical movement of the conductor segment holding jig is restricted.

After the conductor segment holding jig is fixed by the clamper and the conductor segment holding jig holder, the ring jig, which is a torsion molding part, is lowered from the upper part, and the conductor segment insertion part formed in the ring jig is inserted. Usually, one end of the conductor segment is inserted. It should be noted that normally, only the end portion of the conductor segment, which later becomes a joint portion, is inserted into the conductor segment insertion portion. However, in step S2, when the stator core into which the normal conductor segment and the lead conductor segment are inserted is prepared, the lead conductor segment also needs to be twisted at the same time, so that the conductor segment insertion portion of the ring jig needs to be twisted at the same time. A part is formed deep by the length of the lead conductor segment. Further, since the end portion of the conductor segment is usually formed with a tapered chamfered portion 31c as shown in the enlarged view of FIG. 5, it is smoothly inserted into the conductor segment insertion portion.

A ring jig in which one end of a conductor segment is usually inserted into a conductor segment insertion portion is rotated and lowered by a rotation drive mechanism and a lowering drive mechanism. Twisting is usually performed on all conductor segments at the same time. The ring jig is divided into a ring jig that twists the conductor segment of the inner layer and a ring jig that twists the conductor segment of the outer layer, and the divided ring jigs have different directions. It is rotated by a predetermined angle so as to be.

In the twisting process, the conductor segment holding jig in which the conductor segment is normally inserted into the slot is attached to the first twisting machine, and one end of the conductor segment is usually inserted into the ring jig before twisting. It includes a mounting step for preparing, a molding step, and a taking-out step for taking out the molded conductor segment holding jig. Here, in the molding step, first, the end portion of the normal conductor segment is rotationally displaced only in the circumferential direction to tilt the normal conductor segment in the circumferential direction, and then the normal conductor segment is displaced in the circumferential direction and the axial direction to displace the conductor segment. A bending process that tilts deeply, an excessive bending process that displaces the end of the conductor segment in the circumferential direction and the axial direction beyond the design displacement, and tilts the conductor segment excessively deeply, and the end of the normal conductor segment. It includes a return step of bending back to the design displacement amount.

The molding process will be described in more detail.
First, only the ring jig is rotated up to a predetermined angle. This rotation to a predetermined angle bends the conductor segment at the exit portion of the slot and the inlet portion of the conductor segment insertion portion of the ring jig. At this time, as shown in FIG. 7, the conductor segment is provided with two portions having the minimum cross-sectional area, and the portion having the minimum cross-sectional area is the position where the conductor segment is bent. The force to bend the segment can be relieved. As a result, the possibility that the insulating coating of the conductor segment is damaged in this step is reduced, and the dielectric strength of the conductor segment is improved.

Next, the ring jig is rotated by controlling the elevating drive mechanism and the rotation drive mechanism so that the length of the conductor segment from the end of the slot to the conductor segment insertion portion of the ring jig is kept constant. While lowering. At this time, as shown in FIG. 9, the ring jig descends while rotating so that the end portion of the conductor segment draws an arc-shaped locus centered on the axis of the conductor segment holding jig. In order to prevent the conductor segment from being deformed by the springback, the twist that draws the arc-shaped locus is once twisted in excess of the design displacement amount.

Finally, the ring jig rises while rotating in the opposite direction to the previous process, and moves in the opposite direction on the same trajectory up to the design displacement amount. In this way, the torsional molding of the conductor segment is completed, and the ring jig is raised to remove the end portion of the conductor segment from the conductor segment insertion portion of the ring jig. The ring jig from which the conductor segment has been removed is rotated by the rotation drive mechanism and returned to the origin position. In this way, as shown in FIG. 10A, the side surfaces of the adjacent end portions of the paired normal conductor segments 30a are kept in a state of being substantially in contact with each other. As shown in FIG. 10A, it is desirable that the side surfaces of the adjacent ends of the paired normal conductor segments 30a are in contact with each other, but they are not necessarily in contact with each other. In laser welding, the ends of a pair of ordinary conductor segments 30a may be melt-connected and close to each other to a distance at which a joint can be formed.

In the present embodiment, by adjusting the rotation angle so that the lengths of the arcs centered on the axis of the stator core are the same, as shown in FIG. 8, the rods having a single shape have the same length. A conductor segment can be used. Therefore, equipment costs and processing costs can be suppressed, and in the conductor segment pairs to be joined to each other, by aligning the positions of the joint surfaces at the ends of the conductor segments, the joint end surfaces can be accurately aligned, resulting in poor welding. Can be reduced.

In the twisting process, a holding mechanism for the normal conductor segment is required in order to twist the normal conductor segment with high accuracy. This mechanism is usually important in determining the height of the conductor segment. In the normal conductor segment holding mechanism, after installing the conductor segment holding jig in the first twister, the receiver installed below the conductor segment holding jig is moved up and down to adjust the protrusion length of the normal conductor segment. It is a mechanism for fixing the conductor segment. After that, by going through the above-mentioned twisting step, accurate twisting can be realized. By fixing the normal conductor segment and regulating the height, the height of the end portion of the normal conductor segment after twisting can be made uniform. As a result, in the joint forming step using laser welding, the height variation of the end portion of the conductor segment is reduced, which is effective in reducing welding defects.

Insulator insertion step (step S4)
The outer diameter of one end of the insulator is larger than the outer diameter of the slot, and the outer diameter of the other end is smaller than the inner diameter of the slot. That is, one end of the insulator is formed in a trumpet shape. As described above, only one end in the axial direction of the insulator inserted into each slot of the stator core becomes a trumpet-shaped enlarged portion, and the other end has a flat shape. Therefore, it becomes easier to insert the insulator into each slot with the other end at the beginning. Further, since the insertion direction of the insulator and the insertion direction of each conductor segment are the same, even if an axial force is applied to the insulator when the conductor segment is inserted, the end of the enlarged portion is a stator. It comes into contact with the end face of the iron core to prevent the insulator from being displaced in the axial direction.

Conductor segment assembly insertion step (step S5)
The normal conductor segment whose one end is twisted in the one-side twisting step of the normal conductor segment in step S3 is pulled out from the conductor segment holding jig. At this time, the conductor segments are usually maintained in a state of being arranged in an annular shape. Separately, a lead conductor segment with one end twisted is prepared, and the lead conductor segment is inserted at a predetermined position between the normal conductor segments in which the annular arrangement is maintained, and one end is inserted. Form an aggregate of conductor segments in a twisted state. Finally, the conductor segment assembly is inserted into the slot of the stator core into which the insulator is inserted in the insulator insertion step of step S4.

It is preferable that the process of extracting the conductor segment from the conductor segment holding jig and the process of inserting the conductor segment aggregate into the stator core are performed in the same equipment. For example, a regulating jig is prepared in which regulatory pieces having the same width as the spacing between adjacent slots of the stator core are arranged in a circumferential shape at the same pitch as the slots. The regulation jig is arranged so that the regulation piece of the regulation jig is between the linear insertion portions of each conductor segment with respect to the conductor segment assembly arranged in an annular shape. In this state, by moving the stator core and the regulating jig in the axial direction, a set of conductor segments arranged in a circumferential shape at the same pitch as the slot is inserted into the slot of the stator core.

Twisting step on the other end side of the conductor segment assembly (step S6)
The operation of the second twisting machine is the same as that of the first twisting machine in the one-end side twisting step of the normal conductor segment in step S3. The stator core into which the conductor segment assembly twisted at one end is inserted is set in the stator core holder. At this time, it is set so that the other end side is upward. Place a receiver under the stator core that matches the shape of the conductor segment on one end that has been twisted, and expose the other end of all conductor segments above the stator core to the same height. Hold on. The outer peripheral portion of the stator core is fixed by a clamper. Further, by pressing the upper part of the stator core with the stator core retainer, the vertical movement of the stator core is restricted.

After the stator core is fixed by the clamper and the stator core retainer, the annular jig, which is a torsion molding portion, is lowered from the upper part, and the conductor segment aggregate is inserted into the conductor segment insertion portion formed in the annular jig. The other end of the is inserted. It should be noted that only the end portion of the conductor segment assembly, which will later become the joint portion, is inserted into the conductor segment insertion portion. Further, since the end portion of the conductor segment assembly is formed with a tapered chamfered portion 31c as shown in the enlarged view of FIG. 5, it is smoothly inserted into the conductor segment insertion portion.

The ring jig in which the other end of the conductor segment assembly is inserted into the conductor segment insertion portion is rotated and lowered by the rotation drive mechanism and the lowering drive mechanism. The twist forming is performed on all of the conductor segment aggregates at the same time. The ring jig is divided into a ring jig that twists the conductor segment of the inner layer and a ring jig that twists the conductor segment of the outer layer, and the divided ring jigs have different directions. It is rotated by a predetermined angle so as to be.

In the twisting process, the stator core into which the conductor segment assembly is inserted is attached to the second twister, and the other end of the conductor segment assembly is inserted into the ring jig to prepare for twisting. It includes a mounting step of performing the above, a molding step, and a taking-out step of taking out the molded stator core. The molding step is the same as the one-end twisting step of the normal conductor segment in step S3. In this way, the other end side of the conductor segment assembly is twisted.

Although the manufacturing method using the conductor segment holding jig has been described in steps S2 to S4, it is also possible to perform the steps from steps S2 to S4 using a stator core instead of the conductor segment holding jig. Is. By doing so, in the conductor segment assembly insertion step of step S5, it is not necessary to remove the normal conductor segment from the stator core used instead of the conductor segment holding jig, and the lead conductor segment is directly inserted into the stator core. Therefore, the manufacturing man-hours can be further reduced, and the manufacturing cost can be reduced.

Joint forming step (step S7)
A method of joining ordinary conductor segments will be described. Note that this method is a method of joining the ends of different ordinary conductor segments using a plurality of conductor segments in order to form a coil of a rotary electric machine, and is not limited to the shape of the conductor segments. Further, the coil of the rotary electric machine is not limited to the stator coil.

This joining method has two main steps. The first step is usually a step of aligning the ends of the conductor segments. In the step of aligning the ends of the normal conductor segments, the two normal conductor segments to be joined are substantially in contact with each other on the side surfaces of the adjacent ends of the normal conductor segments 30a, as shown in FIG. 10A. It is held in the state. Normally, in the process of aligning the ends of the conductor segments, after fixing the stator that has completed the twisting process at both ends, the conductor segment in the slot is moved and fixed in the circumferential direction using a conical taper pin. The ends of the conductor segments are retained. As shown in FIG. 10A, the insulating coating 31d in a predetermined region is removed from the tip of the end of the normal conductor segment 30a of the object to be joined.

The second step is a laser irradiation step of irradiating the ends of two adjacent conductor segments with the laser beam of a laser welder at a predetermined irradiation angle to weld and join the ends of the conductor segments. As shown in FIG. 10A, at this time, the ends of the normal conductor segments 30a are welded by advancing the laser beam in the radial direction, and as shown in FIG. 10B, the normal conductor segments are welded. A joint portion 32a for joining 30a to each other is formed. At this time, the laser beam is first irradiated aiming at one side of the two adjacent ends, and then the laser beam is moved to the other side. Since the gap between the two adjacent ends is fine, the molten conductor at one end fills the gap with the other end before moving the laser beam. As a result, the laser light is transferred from one end irradiated with the laser light to the other end, and the other end is also melted. In this way, as shown in FIG. 10B, by welding and joining the ends of the two conductor segments, a melt mark is formed as the joint portion 32a. The laser welding in the second step is performed in an atmosphere of an inert gas. In this way, a joint is formed of a normal conductor segment inserted into the stator core and twisted at both ends.

In the present embodiment, the shape of the joint portion is not particularly limited, but the shape of the joint portion may be non-uniform in the circumferential direction in order to reduce pitch noise.
FIG. 15 is a schematic cross-sectional view of the joint portion of the conductor segment during laser welding in the joint portion forming step. FIG. 15 shows a cross section of a conductor segment inserted into one slot. As shown in FIG. 15A, four conductor segments are inserted into one slot, and the two on the inner layer side and the two on the outer layer side are joined at the joint portion 32a, respectively. In FIG. 15, the lateral direction is the radial direction of the stator core, the left side is the inner peripheral side, and the right side is the outer peripheral side. As shown in FIG. 15A, when laser welding is performed, the inert gas is blown from the inner peripheral side to the welded portion on the inner layer side. Then, cooling of the molten metal by irradiation with laser light starts from the side where the inert gas is blown, and the molten metal is biased toward the inner peripheral side at the joint portion 32a of the inner layer due to surface tension to form a protruding portion 32b. To. On the other hand, since the joint portion 32a of the outer layer is not affected by the sprayed gas, the molten metal is not biased toward the inner peripheral side or the outer peripheral side, and the joint portion is uniformly formed.

FIG. 15B shows a case where six conductor segments are inserted into one slot, and two conductor segments on the inner layer side, two on the intermediate layer side, and two on the outer layer side are joined at the joint portion 32a, respectively. ing. As shown in FIG. 15B, when laser welding is performed, the inert gas is blown from the inner peripheral side to the welded portion on the inner layer side. Then, cooling of the molten metal by irradiation with laser light starts from the side on which the inert gas is blown, and the molten metal is biased toward the inner peripheral side due to surface tension to form the protruding portion 32b. On the other hand, since the joint portion 32a of the intermediate layer and the outer layer is not affected by the sprayed gas, the molten metal is not biased toward the inner peripheral side or the outer peripheral side, and the joint portion is uniformly formed.

Further, when laser welding is performed while blowing an inert gas from the outer peripheral side to the welded portion on the outer layer side, cooling of the molten metal by irradiation of laser light starts from the side where the inert gas is blown, and due to surface tension. The molten metal is biased toward the outer peripheral side to form the protruding portion 32b.

As described above, in the stator of the present embodiment, the protrusion 32b protruding inward in the radial direction is formed at at least one joint 32a of the innermost conductor segment, and at least one of the outermost conductor segments is formed. A protruding portion 32b protruding outward in the radial direction is formed at the joint portion 32a.

FIG. 16 is a top view of the stator of the present embodiment as viewed from the axial direction. FIG. 16A shows an example in which four conductor segments are inserted into one slot, and a protrusion 32b is formed at at least one joint portion 32a of the innermost conductor segment. .. The AA cross section of FIG. 16A corresponds to FIG. 15A. Assuming that the radial length of the joint portion 32a on the inner layer side is L1 and the radial length of the joint portion 32a on the outer layer side is L2, L1> L2. Further, assuming that the radial length of the joint portion 32a on the inner layer side of the other slot having no protruding portion is L3, L1> L3.

FIG. 16B shows an example in which four conductor segments are inserted into one slot, and a protrusion 32b is formed at at least one joint portion 32a of the outermost conductor segment. Normally, a joint portion 32a is formed at the end portion of the conductor segment 30a, but a joint portion is not formed at the end portion of the lead conductor segment 30b. Assuming that the radial length of the joint portion 32a on the inner layer side is L3 and the radial length of the joint portion 32a on the outer layer side is L4, L4> L3. Further, assuming that the radial length of the joint portion 32a on the outer layer side of the other slot having no protruding portion shown in FIG. 16A is L2, L4> L2.

FIG. 16C shows a case where six conductor segments are inserted into one slot, and two conductor segments on the inner layer side, two on the intermediate layer side, and two on the outer layer side are joined at the joint portion 32a, respectively. ing. Further, FIG. 16C shows an example in which the protruding portion 32b is formed at at least one joint portion 32a of the innermost conductor segment. The BB cross section of FIG. 16 (c) corresponds to FIG. 15 (b). Assuming that the radial length of the joint portion 32a on the inner layer side is L5, the radial length of the joint portion 32a of the intermediate layer is L6, and the radial length of the joint portion 32a on the outer layer side is L7, L5> L6. ≈L7. Further, assuming that the radial length of the joint portion 32a on the inner layer side of the other slot having no protruding portion is L8, L5> L8.

FIG. 16D shows an example in which six conductor segments are inserted into one slot, and a protrusion 32b is formed at at least one joint portion 32a of the outermost conductor segment. Normally, a joint portion 32a is formed at the end portion of the conductor segment 30a, but a joint portion is not formed at the end portion of the lead conductor segment 30b. Assuming that the radial length of the joint portion 32a on the inner layer side is L8, the radial length of the joint portion 32a of the intermediate layer is L9, and the radial length of the joint portion 32a on the outer layer side is L10, L10> L8. ≈L9. Further, assuming that the radial length of the joint portion 32a on the outer layer side of the other slot having no protruding portion shown in FIG. 16C is L7, L10> L7.

FIG. 16E shows a case where four conductor segments are inserted into one slot, and the conductor segment of the innermost layer having the joint portion 32a in which the protruding portion 32b is formed toward the inner peripheral side, and the outer circumference. An example is shown in which the conductor segment of the outermost layer having the joint portion 32a in which the protrusion portion 32b is formed toward the side is inserted into the same slot.

FIG. 16 (f) shows a case where six conductor segments are inserted into one slot, and the conductor segment of the innermost layer having the joint portion 32a in which the protruding portion 32b is formed toward the inner peripheral side, and the outer circumference. An example is shown in which the conductor segment of the outermost layer having the joint portion 32a in which the protrusion portion 32b is formed toward the side is inserted into the same slot.

As described above, the axial end portion of the conductor segment of the stator of the present embodiment is joined to the other conductor segment to be paired at the joint portion, and among the plurality of conductor segments inserted into each slot, At least one of the joints of the conductor segments inserted on the outermost peripheral side has a protrusion on the outer peripheral side that protrudes radially outward from the other joints, and a plurality of conductor segments inserted into each slot. Of these, at least one of the joints of the conductor segment inserted on the innermost peripheral side includes a protrusion on the inner peripheral side that protrudes radially inward from the other joints.

Since the rotary electric machine provided with the stator configured in this way has a non-uniform shape of the joint in the circumferential direction, pitch noise can be reduced. Further, since the protruding portion on the outer peripheral side and the protruding portion on the inner peripheral side project in the radial direction, the joint portion can be efficiently cooled without hindering the passage of the cooling air flowing in the radial direction. Therefore, the rotary electric machine provided with the stator of the present embodiment can achieve both reduction of pitch noise and improvement of cooling performance of the joint portion of the conductor segment.

In the present embodiment, when laser welding is performed, laser welding is performed while blowing an inert gas to form a protruding portion, but the present invention is not limited to this. For example, there is a method of irradiating the end of the conductor segment with laser light from only one of the radial directions. In this method, due to the time difference between the start of melting of the molten portion, the end face melted first is cooled and solidified, so that the melting marks of the joint portion are biased to the incident side of the laser beam due to surface tension. The protrusion can also be formed in this way. Further, since the melting marks of laser welding are biased toward the inner peripheral side or the outer peripheral side to form the protruding portion, it is possible to suppress the spread of the melting marks on the side opposite to the protruding portion. As a result, as shown in FIGS. 16A to 16D, the distance W3 between the adjacent joints becomes large, and the insulation distance between the stator coils can be reliably secured.

In order to further improve the insulating properties between the joints, it is preferable that L5> L7> L6 in FIG. 16C. Further, in FIG. 16D, it is preferable that L10> L8> L9. That is, in each slot, the radial dimension of the joint portion of the conductor segment inserted between the conductor segment inserted on the innermost peripheral side and the conductor segment inserted on the outermost peripheral side is set to the innermost peripheral side. It is preferably smaller than the radial dimension of the joint portion of the inserted conductor segment and the radial dimension of the joint portion of the conductor segment inserted on the outermost peripheral side. In the stator configured in this way, the distances W3 and W4 between the adjacent joints are increased, and the insulation distance between the stator coils can be further increased. Although it depends on the rated voltage, for example, in a 48V rotary electric machine, the interval W3 and the interval W4 need to be 0.8 mm or more, and the shape of the present embodiment ensures the insulation distance between the conductor segments. It will be easy.

In the present embodiment, the method of forming the joint portion by laser welding has been described, but the present invention is not limited to this. For example, the joint may be formed by arc welding, caulking, or the like.

Although various exemplary embodiments have been described in the present application, the various features, embodiments, and functions described in one or more embodiments are limited to the application of the particular embodiment. Rather, it is applicable to embodiments alone or in various combinations.
Therefore, innumerable variations not illustrated are envisioned within the scope of the techniques disclosed in the present application. For example, it is assumed that at least one component is modified, added or omitted, and further, at least one component is extracted and combined with the components of other embodiments.

1 Rotor, 2 Rotor, 3 Front bracket, 4 Rear bracket, 3a, 4a Intake hole, 3b, 4b Exhaust hole, 5 Housing, 6 Shaft, 7 Stator, 8 Pulley, 9 Slip ring, 10 Brush, 11 Brush Holder, 12 regulator, 13 heat sink, 14 rectifier, 15 cooling fan, 21 rotor coil, 22, 23 pole core, 24, 25 claw pole, 30 conductor segment, 30a normal conductor segment, 30b lead conductor segment, 31a insertion part, 31b coil end, 31c chamfer, 31d insulation coating, 32a joint, 32b protrusion, 71 stator core, 71a slot, 71b core back, 71c teeth, 72 stator coil, 73 insulator, 74 conductor segment holding jig ..

The stator according to the present application has a stator core having a plurality of slots arranged in an annular shape and a plurality of conductor segments inserted in each slot in a radial direction, and an axial end portion of the conductor segment. Is joined to the axial end of the other pair of conductor segments at the joint, and the conductor segment is bent in an arc shape from the end of the slot toward the joint, and the pair of conductor segments and the arc length as viewed from the axial direction between the same, the height from the end portion of the joint portion of the slot of the conductor segments inserted into the inner diameter side of the slot, are inserted on the outer diameter side of the slot conductor It is higher than the height from the end of the slot at the junction of the segments .

In the present application the stator, and the conductor segments are bent in an arc shape toward the joint from the end of the slot, the same length of arc as viewed from the axial direction of the conductor segments between the paired slots The height of the joint of the conductor segment inserted on the inner diameter side of the slot from the end of the slot should be higher than the height of the joint of the conductor segment inserted on the outer diameter side of the slot from the end of the slot. Therefore, a stator coil can be manufactured using conductor segments of the same length. As a result, the manufacturing cost of the stator can be suppressed.

Claims (10)

A stator core with multiple slots arranged in an annular shape,
A stator having a plurality of conductor segments inserted radially into each slot.
The axial end of the conductor segment is joined to the axial end of another pair of conductor segments at a joint.
The conductor segment is bent in an arc shape from the end of the slot toward the joint, and the lengths of the arcs of the paired conductor segments viewed from the axial direction are the same. stator. The height of the joint of the conductor segment inserted into the inner diameter side of the slot from the end of the slot is the end of the slot of the joint of the conductor segment inserted into the outer diameter side of the slot. The stator according to claim 1, wherein the stator is higher than the height from the portion. The stator according to claim 1 or 2, wherein the lengths from the ends of the slots to the joints of the plurality of conductor segments are the same. The stator according to any one of claims 1 to 3, wherein the cross-sectional area of the conductor segment at a position exposed from the end of the slot is the minimum cross-sectional area of the conductor segment. At least one of the joints of the conductor segment inserted into the innermost side of the plurality of slots has an inner protrusion that protrudes radially inward from the other joints.
At least one of the joints of the conductor segment inserted into the outermost periphery of the plurality of slots is characterized by having a protrusion on the outer periphery that protrudes radially outward from the other joints. The stator according to any one of claims 1 to 4. The aspect according to any one of claims 1 to 5, wherein the axial end portion of the conductor segment is cut out from a surface opposite to a surface facing another pair of conductor segments. stator. With the housing
The stator according to any one of claims 1 to 6 fixed to this housing, and
A rotary electric machine characterized in that a rotor provided rotatably with respect to the stator is provided on the inner diameter side of the stator. A first conductor segment insertion step of inserting a plurality of rod-shaped first conductor segments having the same length into each of the plurality of slots using a conductor segment holding jig having a plurality of slots arranged in an annular shape.
The first conductor segment holding jig is inserted into each of the plurality of slots so that one end portion of the first conductor segment comes into contact with the other end portion of the other first conductor segment to be paired with the first conductor segment. One end side twisting process of the first conductor segment that twists and bends the one conductor segment in an arc shape,
The first conductor segment bent in the one-end twisting step of the first conductor segment is taken out from the conductor segment holding jig, and the conductor segment assembly is formed by the first conductor segment and the second conductor segment provided with the lead wire portion. A conductor segment assembly insertion step of forming a body and inserting the conductor segment aggregate into the plurality of slots of a stator core having a plurality of slots arranged in an annular shape.
The other first conductor segment in which the other end of the first conductor segment included in the conductor segment assembly inserted into the plurality of slots of the stator core in the conductor segment assembly insertion step is paired. The other end side twisting step of the conductor segment assembly, which twists and bends the conductor segment assembly in an arc shape so as to come into contact with the other end portion of the conductor segment assembly.
The one end and the other end of the first conductor segment to be paired in the one-side twisting step of the first conductor segment and the other-side twisting step of the conductor segment assembly are melted and joined, respectively. It is a method of manufacturing a stator including a joint forming step of forming a stator.
In the step of twisting one end side of the first conductor segment and the step of twisting the other end side of the conductor segment assembly, the first conductor segment is bent in an arc shape from the end of the slot toward the joint to form a pair. A method for manufacturing a stator, characterized in that the lengths of arcs viewed from the axial direction of the first conductor segments are the same. In the first conductor segment inserting step and the one end side twisting step of the first conductor segment, the stator core is used instead of the conductor segment holding jig, and the conductor segment assembly inserting step is performed in the first conductor segment. 8. The eighth aspect of claim 8, wherein the second conductor segment provided with the lead wire portion is inserted into the slot of the stator core in a state in which the first conductor segment bent in the one-end side twisting step is inserted. How to make a stator. Insertion of a conductor segment into which a plurality of rod-shaped first conductor segments having the same length and a second conductor segment having a lead wire portion are inserted into each of the plurality of slots of a stator core having a plurality of slots arranged in an annular shape. Process and
The other first conductor segment or the other one of the second conductor segment in which one end of the first conductor segment and the second conductor segment inserted into each of the plurality of slots of the stator core is paired. One end side twisting step of the conductor segment that twists and bends the first conductor segment and the second conductor segment in an arc shape so as to come into contact with the end portion of
The first conductor segment so that the other end of the first conductor segment inserted into the plurality of slots of the stator core is in contact with the other end of the other first conductor segment to be paired. The other end twisting process of the conductor segment that twists and bends in an arc shape,
The first conductor segment and the one end of the second conductor segment that are paired in the one-end twisting step of the conductor segment, and the first conductor segment that is paired in the other end twisting step of the conductor segment. A method for manufacturing a stator, which comprises a joint portion forming step of melting the other end portions to form a joint portion.
In the one-side twisting step of the conductor segment and the other-end twisting step of the conductor segment, the first conductor segment is bent in an arc shape from the end of the slot toward the joint to form a pair. A method for manufacturing a stator, which comprises making the lengths of arcs of conductor segments seen from the axial direction the same.

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