JP2024043700A - Rotary electric machine and manufacturing method of rotary electric machine - Google Patents

Abstract

To provide a rotary electric machine in which there is no positional displacement of a segment coil or no generation of a clamp mark and there is no fluctuation in shape of a coil end.SOLUTION: A rotary electric machine comprises a stator core including a plurality of slots and a plurality of segment coils inserted into the slots. Each of the plurality of segment coils includes: a skew part which protrudes from one end face of the stator core and is folded obliquely in a circumferential direction of the stator core; and a rise part which is disposed at a front end side of the skew part and rises in an axial direction of the stator core. A pair of rise parts of the segment coils of the same phase with different bending directions of the skew parts is arrayed and joined in a radial direction. The pair of rise parts joined crosses at a position closer to the stator core than front ends of the rise parts in a view in the radial direction of the stator core.SELECTED DRAWING: Figure 6

Description

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

Conventionally, a rotating electric machine is known in which a segment coil protruding from one end face of a stator core has a diagonal portion bent diagonally in the circumferential direction of the stator core and a rising portion disposed at the tip side of the diagonal portion, and is obtained by joining a pair of rising portions of segment coils of the same phase, which have different bending directions of the diagonal portion (see, for example, Patent Document 1). The pair of rising portions are clamped in the circumferential direction at a location closer to the stator core than the tip, and are joined by welding the radially aligned tips together.

Patent No. 6549872

Conventional rotating electric machines are based on the premise that the rising portions of the segment coils are formed so that they stand parallel to the axial direction of the stator core (perpendicular to the end face of the stator core). However, after bending, the rising portions do not necessarily stand parallel to the axial direction of the stator core due to variations caused by springback, etc., which can result in the following problems:

If the rising parts are inclined in the same direction as the inclined part, when the tips of the pair of rising parts are aligned in the radial direction, the clamp parts closer to the stator core than the tips will move away from each other in the circumferential direction of the stator core. Therefore, when clamping, the diagonal portions connected to the clamped rising portions are pulled toward each other, causing a displacement. The displacement of the diagonal portion affects the diagonal portions of the segment coils in adjacent slots, and the displacement of the segment coils gradually becomes larger. Further, since a reaction force acts on the pair of rising portions when the oblique portion is pulled together, extra force is required during clamping, resulting in larger clamping marks on the rising portions. Further, during clamping, the diagonal portion is pulled and elastically deformed. If the tips of the rising portions are joined together while the diagonal portions are elastically deformed, residual stress may be generated in the segment coil after the clamp is released, and the shape of the joined coil end portion may be disturbed.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a rotating electrical machine and a method for manufacturing the rotating electrical machine that does not cause misalignment of segment coils or large clamp marks, and does not disrupt the shape of coil end portions.

(1) The rotating electric machine according to the present invention includes a stator core (e.g., stator core 5 described later) having a plurality of slots (e.g., slot 52 described later) and a plurality of segment coils (e.g., segment coil 6 described later) inserted into the slots, and the plurality of segment coils protrude from one end face (e.g., end face 5b described later) of the stator core and have an inclined portion (e.g., inclined portion 611 described later) bent obliquely in the circumferential direction of the stator core and a rising portion (e.g., rising portion 612 described later) arranged at the tip side of the inclined portion and raised in the axial direction of the stator core, and a pair of the rising portions of the segment coils of the same phase having different bending directions of the inclined portions are arranged in the radial direction and joined (e.g., rotating electric machine 1 described later), and the pair of the joined rising portions intersect at a position closer to the stator core than the tip of the rising portion when viewed from the radial direction of the stator core.

(2) The manufacturing method of a rotating electric machine according to the present invention includes a stator core (e.g., stator core 5 described below) having a plurality of slots (e.g., slot 52 described below) and a plurality of segment coils (e.g., segment coil 6 described below) inserted into the slots, the plurality of segment coils protruding from one end face (e.g., end face 5b described below) of the stator core and including an inclined portion (e.g., inclined portion 611 described below) bent obliquely in the circumferential direction of the stator core and a rising portion (e.g., This is a manufacturing method for a rotating electric machine (for example, rotating electric machine 1 described later) in which a pair of rising parts of the segment coils of the same phase, each having a rising part 612 described later and a bending direction of the oblique part being different, are arranged in the radial direction and joined together, and the pair of rising parts are arranged so as to intersect at a position closer to the stator core than the tip of the rising part when viewed from the radial direction of the stator core, and the pair of rising parts are joined while being clamped from both sides in the circumferential direction of the stator core at the intersecting part (for example, intersecting part Cp described later).

According to the present invention, it is possible to provide a high-quality rotating electrical machine and a method for manufacturing the rotating electrical machine that does not cause displacement of segment coils or large clamp marks, and does not disrupt the shape of coil end portions.

FIG. 1 is a cross-sectional view schematically showing a rotating electrical machine according to an embodiment. FIG. 2 is an exploded perspective view of a stator in the rotating electric machine according to the embodiment. 2 is an oblique view showing how bundled segment coils are inserted into slots of a stator core in a rotating electric machine of the present embodiment. FIG. 2 is an oblique view showing a state in which all segment coils are inserted into the slots of a stator core in a rotating electric machine of the present embodiment. FIG. It is a figure showing the shape of the end of the bent segment coil in the rotary electric machine of this embodiment. FIG. 3 is a diagram showing a coil end portion in the rotating electric machine of the present embodiment. 11 is a plan view illustrating a state in which a rising portion of a coil end portion is clamped in the manufacturing method for a rotating electric machine according to the embodiment. FIG. 10A to 10C are diagrams illustrating a state in which a pair of rising portions of a coil end portion are clamped in the manufacturing method for the rotating electric machine according to the embodiment. FIG. 3 is a diagram schematically showing how a pair of rising portions of a coil end portion are clamped in the method for manufacturing a rotating electric machine according to the present embodiment.

Hereinafter, a rotating electrical machine and a method for manufacturing the rotating electrical machine according to the present embodiment will be described in detail with reference to the drawings. The rotating electrical machine 1 shown in FIG. 1 includes a housing 2, a rotor 3, and a stator 4. The rotating electric machine 1 is, for example, an inner rotor type, and is a three-phase AC brushless DC motor of U phase, V phase, and W phase. In the rotating electric machine 1 and the stator 4, the circumferential direction is the X direction along the rotation direction of the rotation shaft 31 of the rotor 3. The radial direction is the Y direction along the radial direction centered on the rotating shaft 31 of the rotor 3. The axial direction is the Z direction along the length direction of the rotating shaft 31 of the rotor 3.

The housing 2 is formed into a cylindrical shape from a metal material with good thermal conductivity, such as copper or aluminum. Inside the housing 2, a refrigerant flow path 21 is formed to allow the refrigerant to flow. The stator 4 is fixed to the inner peripheral surface 2a of the housing 2.

The rotor 3 has multiple permanent magnets for a field magnet (not shown) arranged around the outer periphery of the rotating shaft 31. The rotating shaft 31 of the rotor 3 is rotatably supported by a motor housing (not shown) or the like.

As shown in Figures 1 and 2, the stator 4 includes a stator core 5 and a number of segment coils 6 attached to the stator core 5.

The stator core 5 includes, for example, an annular portion 51 made of a laminate in which a plurality of thin core plates are laminated, and a plurality of slots 52 passing through the annular portion 51 in the axial direction. The plurality of slots 52 are arranged radially around a through hole 50 that axially passes through the center of the stator core 5 at regular intervals in the circumferential direction.

The segment coil 6 is constructed by, for example, forming a conductor made of a flat wire with a rectangular cross section into a substantially U-shape. As shown in FIGS. 2 and 3, the segment coil 6 includes a pair of parallel straight portions 61 and a connecting portion 62 that connects one end portions of the pair of straight portions 61 to each other. In this embodiment, as shown in FIG. 3, four segment coils 6 are stacked and bundled in the radial direction of the stator core 5. The bundled four segment coils 6 are attached to the stator core 5 by inserting one straight portion 61 and the other straight portion 61 into two different slots 52, 52, respectively.

In this embodiment, the straight portions 61 of the four segment coils 6 bundled together and the straight portions 61 of the four segment coils 6 bundled separately overlap each other in the radial direction of the stator core 5 in one slot 52. and inserted. As a result, the straight portions 61 of the eight segment coils 6 are inserted into each slot 52 and stacked in the radial direction of the stator core 5. As shown in FIG. 4, the straight portions 61, 61 disposed at both ends of each segment coil 6 inserted into the slot 52 have an end surface opposite to the end surface 5a on the insertion side in the axial direction of the stator core 5. It protrudes upright from the end surface) 5b. Although insulating members are inserted into the slots 52 of the stator core 5, the insulating members are not shown in the stator core 5 shown in each figure.

After all the segment coils 6 are inserted into all the slots 52 of the stator core 5, the straight portions 61 protruding from the end surface 5b of the stator core 5 are respectively bent in the circumferential direction of the stator core 5. As will be described in detail later, the tips of the straight portions 61 of the bent segment coils 6 of the same phase are aligned in the radial direction and joined by welding.

Figure 5 shows two straight portions 61, 61 of a segment coil 6 protruding from the end face 5b of the stator core 5. The two straight portions 61, 61 are arranged adjacent to each other in the radial direction of the stator core 5 within the same slot 52. Each segment coil 6 is entirely covered with a resin insulating coating 6A, but only the tip portion 61a of each straight portion 61 of the segment coil 6 has the insulating coating 6A completely peeled off over a predetermined length. This forms a peeled-off coating portion 6B at each tip portion 61a of the straight portion 61.

The straight portion 61 of the segment coil 6 protruding from the end surface 5b of the stator core 5 is bent obliquely in the circumferential direction of the stator core 5 at a portion of the insulating coating 6A near the slot 52. As a result, diagonal portions 611 are formed. Further, the film peeling portion 6B disposed on the tip side of the diagonal portion 611 is bent so as to stand up in the axial direction of the stator core 5 with respect to the diagonal portion 611. As a result, rising portions 612 are formed on the distal end sides of the diagonal portions 611, respectively.

The straight portions 61 inserted into the same slot 52 and adjacent in the radial direction of the stator core 5 are bent obliquely in opposite directions along the circumferential direction of the stator core 5 to form the oblique portions 611. In more detail, as shown in FIG. 5, of the two straight portions 61, 61 adjacent in the radial direction of the stator core 5, the oblique portion 611 of one straight portion 61 is bent in the X1 direction along the circumferential direction of the stator core 5. The oblique portion 611 of the other straight portion 61 is bent in the X2 direction along the circumferential direction of the stator core 5. In each slot 52, the oblique portions 611 of the straight portions 61 arranged at the same position in the radial direction of the stator core 5 are bent in the same direction, the X1 direction or the X2 direction.

The rising portions 612 are each formed only by the coating peeling portion 6B. The bending start point P of the rising portion 612 is located on the coating peeling portion 6B, which is closer to the tip than the boundary portion 6C between the insulating coating 6A and the coating peeling portion 6B, and is not located on the insulating coating 6A. Therefore, the bending stress during bending does not act on the insulating coating 6A, and no peeling residue of the insulating coating 6A is generated.

The angle θ (the angle on the side farther from the slot 52 into which the straight portion 61 having the rising portion 612 is inserted) formed by the line DL along the rising direction of the rising portion 612 after bending at the bending starting point P and the end face 5b of the stator core 5 in the circumferential direction of the stator core 5 is smaller than 90 degrees. Therefore, the rising portion 612 is slightly inclined along the bending direction of the oblique portion 611. The rising portion 612 having such an inclination angle can be formed, for example, by appropriately setting the bending angles when bending the oblique portion 611 and the rising portion 612, taking into account the occurrence of springback after forming.

In the straight parts 61 of all the segment coils 6 inserted into the slots 52 of the stator core 5, a rising part 612 consisting of a diagonal part 611 and a film peeling part 6B is bent and formed by a known method in the same manner as described above. . As a result, as shown in FIG. 6, a coil end portion 60 is formed on the end surface 5b side of the stator core 5, which is made up of the ends of a plurality of segment coils 6 in which a diagonal portion 611 and a rising portion 612 are bent and formed. .

In the coil end portion 60, the respective rising portions 612 of the segment coils 6 in the same phase are arranged in the radial direction of the stator core 5. As shown in FIG. 6, the rising portions 612, 612 of segment coils 6, 6 of the same phase, which are adjacent to each other in the radial direction of the stator core 5 and whose diagonal portions 611 are bent in opposite directions, are separated from each other in the radial direction of the stator core 5. As seen, the rising portions 612, 612 intersect at a position closer to the stator core 5 than the tips 612a, 612a. That is, the intersection Cp of the pair of rising portions 612, 612 is disposed midway in the extending direction of the rising portions 612, 612. Specifically, this intersection Cp is arranged at a portion to be clamped from the circumferential direction of the stator core 5 by a clamp jig during joining, which will be described later.

As a specific means for arranging the pair of rising portions 612, 612 to intersect with each other at the intersection Cp, for example, the slope of the segment coil 6 protruding from the end surface 5b of the stator core 5 may be For example, the length of the row portion 611 may be made longer than the normal length, or the length of the rising portion 612 may be made longer than the normal length. Methods for making the length of the diagonal portion 611 longer than the normal length include a method of setting the design value of the length of the straight portion 61 of the segment coil 6 longer than usual, and a method of bending and forming the diagonal portion 611. In this case, a method may be used in which the stator core 5 is stretched by applying a tension larger than usual in the circumferential direction of the stator core 5 so that the diagonal portion 611 is formed to have a longer length than the normal length.

In the coil end portion 60, the plurality of rising portions 612 arranged in the radial direction of the stator core 5 are clamped by the clamp jig 7 from the radial direction of the stator core 5, as shown in FIG. 7, at the time of joining. The clamp jig 7 has a pair of clamp bodies 71, 71. The pair of clamp bodies 71, 71 are arranged to face each other so as to sandwich one row of rising portions 312 arranged in the radial direction of the stator core 5 from the circumferential direction of the stator core 5. The pair of clamp bodies 71, 71 are driven by a drive unit (not shown) to move toward each other and clamp the row of rising portions 312.

As shown in FIG. 8, the pair of clamp bodies 71, 71 of the clamp jig 7 sandwich the intersection Cp of the pair of rising portions 612, 612 adjacent to each other in the radial direction of the stator core 5 from the circumferential direction of the stator core 5. be placed in a position where it can be Thereafter, as shown in FIG. 9, the pair of clamp bodies 71, 71 are moved in a direction closer to each other by driving of a drive unit (not shown), and the row of rising portions 312 is clamped. Since the row of rising portions 612 is clamped at the intersection Cp, the rising portions 612 will not be displaced in the radial direction of the stator core 5 during clamping. Since the diagonal portion 611 is not pulled during clamping, no unnecessary force is applied to the clamp jig 7.

After clamping, the pair of rising portions 612, 612 are welded and joined. After joining, the clamping jig 7 releases the clamp and moves to clamp another row of rising portions 612 in the same way. When all of the rising portions 612 of the coil end portion 60 are welded, the joining operation is completed. Since each diagonal portion 611 of the coil end portion 60 does not elastically deform when clamped, even if the clamp is released after joining, no residual stress is generated in the segment coil 6 due to the elastic deformation of the diagonal portions 611.

The stator 4 obtained in this manner is fixed to the inner peripheral surface 2a of the housing 2, and the rotor 3 is accommodated in the through hole 50, thereby manufacturing the rotating electric machine 1.

According to the rotating electrical machine 1 and the method for manufacturing the rotating electrical machine 1 of this embodiment, the following effects are achieved.

The rotating electric machine 1 according to the present embodiment includes a stator core 5 having a plurality of slots 52 and a plurality of segment coils 6 inserted into the slots 52. It has a diagonal portion 611 that protrudes and is bent obliquely in the circumferential direction of the stator core 5, and a rising portion 612 that is disposed on the tip side of the diagonal portion 611 and is raised in the axial direction of the stator core 5. However, the rotating electric machine 1 is a rotating electric machine 1 in which a pair of rising portions 612, 612 of the same phase segment coil 6 whose diagonal portions 611 are bent in different directions are arranged and joined in the radial direction, and the pair of rising portions 612, 612 to be joined are 612 intersect at a position closer to the stator core 5 than the tips 612a, 612a of the rising portions 612, 612, when viewed from the radial direction of the stator core 5.

According to this, when the intermediate portions of the pair of rising portions 612, 612 are clamped during joining, the positional deviation of the rising portions 612, 612 will not occur. Since the rising portion 612 does not pull the oblique portion 611 during clamping, no unnecessary force is applied to the clamping jig 7, and large clamping marks are not formed on the rising portion 612. Since residual stress due to elastic deformation of the diagonal portion 611 is not generated in the segment coil 6 after the clamp is released, the shape of the coil end portion 60 is not disturbed. Thereby, a high-quality rotating electrical machine 1 can be provided.

The manufacturing method of the rotating electric machine 1 according to this embodiment includes a stator core 5 having a plurality of slots 52 and a plurality of segment coils 6 inserted into the slots 52. The plurality of segment coils 6 protrude from one end face 5b of the stator core 5 and have a diagonal portion 611 bent obliquely in the circumferential direction of the stator core 5 and a rising portion 612 arranged at the tip side of the diagonal portion 611 and raised in the axial direction of the stator core 5. The manufacturing method of the rotating electric machine 1 includes arranging and joining a pair of rising portions 612 of the same phase segment coils 6 having different bending directions of the diagonal portion 611 in the radial direction, and the pair of rising portions 612, 612 are arranged so as to intersect at a position closer to the stator core 5 than the tips 612a, 612a of the rising portions 612, 612 when viewed from the radial direction of the stator core 5, and the pair of rising portions 612, 612 are joined in a state where they are clamped from both sides in the circumferential direction of the stator core 5 at the intersection portion Cp.

According to this, the same effects as the rotating electrical machine 1 described above are achieved.

1 Rotating electric machine 4 Stator 5 Stator core 5b End surface (one end surface)
52 Slot 6 Segment coil 611 Oblique section 612 Rising section 612a Tip Cp Crossing section

Claims (2)

The stator core includes a stator core having a plurality of slots, and a plurality of segment coils inserted into the slots, and the plurality of segment coils protrude from one end surface of the stator core and are bent diagonally in a circumferential direction of the stator core. and a rising portion disposed on the tip side of the slanted portion and raised in the axial direction of the stator core, the segment coils having the same phase in which the slanted portions are bent in different directions. A rotating electrical machine in which the pair of rising portions are arranged and joined in a radial direction,
In the rotating electrical machine, the pair of rising portions to be joined intersect at a position closer to the stator core than a tip of the rising portion when viewed from a radial direction of the stator core. The stator core includes a stator core having a plurality of slots, and a plurality of segment coils inserted into the slots, and the plurality of segment coils protrude from one end surface of the stator core and are bent diagonally in a circumferential direction of the stator core. and a rising portion disposed on the tip side of the slanted portion and raised in the axial direction of the stator core, the segment coils having the same phase in which the slanted portions are bent in different directions. A method for manufacturing a rotating electric machine in which a pair of rising portions are arranged and joined in a radial direction,
The pair of rising portions are arranged so as to intersect at a position closer to the stator core than the tips of the rising portions when viewed from the radial direction of the stator core;
A method for manufacturing a rotating electric machine, wherein the pair of rising portions are joined together at the intersecting portions while being clamped from both sides in the circumferential direction of the stator core.

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