WO2018190062A1

WO2018190062A1 - Stator core of dynamo-electric machine, and stator

Info

Publication number: WO2018190062A1
Application number: PCT/JP2018/009981
Authority: WO
Inventors: 川村　浩司; 直弘本石; 尚俊増田; 宙司会田
Original assignee: 三菱電機株式会社
Priority date: 2017-04-12
Filing date: 2018-03-14
Publication date: 2018-10-18
Also published as: JP2020102894A

Abstract

A stator core of a dynamo-electric machine has an annular outer core that is a back yoke part, and an annular inner core that is fitted inside the outer core. The outer core has a plurality of V grooves that open to the inner-circumference side. The inner core has a plurality of teeth disposed a in radial formation. In the plurality of teeth, the inner-circumference sides are linked to each other, and a plurality of slot parts are formed by the side surface of each adjacent tooth. The plurality of teeth have a convex part that engages with each of the V grooves of the outer core at the end part of the outer-circumference side, and respective recesses are formed at the base of the convex part at both side surfaces of each tooth.

Description

Stator core and stator of rotating electrical machines

The present invention relates to a stator core of a rotating electric machine formed by an outer iron core and an inner iron core, and a stator of a rotating electric machine having a stator iron core formed by an outer iron core and an inner iron core.

Conventionally, in a rotating electrical machine, a rotor is disposed on the inner peripheral side of a cylindrical stator via a predetermined gap. In a rotating electrical machine, a stator iron core is known that is divided into an inner iron core having teeth and an outer iron core as a back yoke. In such a rotating electric machine, after the stator winding is incorporated in the inner iron core, the outer iron core is fitted and integrated with the inner iron core to form a stator (see, for example, Patent Document 1).

When the stator core is divided and configured, winding can be performed from the outer peripheral side of the inner core, so that winding work is easier than winding from the inner peripheral side of the stator core. In addition, since the gap between each slot portion formed between adjacent teeth widens from the inner periphery toward the outer periphery, when a coil is disposed in each slot portion, the coil can be pushed in from the outer periphery side with a wide gap. . Therefore, the gap between the coil and the inner iron core and between each coil can be minimized, and high-density winding is possible. As a result, the ratio of the coil cross-sectional area to the cross-sectional area of the slot portion can be increased, and the resistance value of the stator windings can be reduced, so that the loss of the rotating electrical machine can be reduced and the performance can be improved.

Japanese Patent No. 4018474

導体 Conductor wires with an insulation coating are usually used for the coils used for the stator winding, but insulation is insufficient with the insulation coating alone. For this reason, insulating paper made of resin or paper is disposed between the coil and the stator core to ensure a sufficient insulation state. The thinner the insulating paper, the higher the density of the coil in the slot portion, and the performance of the rotating electrical machine is improved. However, in the stator core of Patent Document 1, when the coil is pushed into the slot portion of the divided inner iron core, there is a possibility that the thin insulating paper may come into contact with the edge of the slot portion and be damaged. There has been a problem that sufficient insulation is not ensured.

The present invention has been made to solve the above-described problems, and can prevent the insulation paper from being damaged when the coil is inserted into the slot portion without increasing the thickness of the insulation paper. A stator core for a rotating electrical machine is obtained.

A stator iron core of a rotating electrical machine according to the present invention has an annular outer iron core that is a back yoke portion and an annular inner iron core that is fitted inside the outer iron core, and the outer iron core opens to the inner peripheral side. The inner iron core has a plurality of radially arranged teeth, and the plurality of teeth are connected to each other on the inner peripheral side, and a plurality of slot portions are formed by side surfaces of adjacent teeth. Form. Each of the plurality of teeth has a convex portion that engages with the V-groove of the outer iron core at each end on the outer peripheral side, and a concave portion is formed at each of the base portions of the convex portions on both side surfaces of each tooth.

According to the stator core of the rotating electrical machine of the present invention, it is possible to prevent the insulating paper from being damaged when the coil is assembled to the stator. Thereby, the density of the coil which occupies for a slot part can be made high using insulating paper with thin thickness. Therefore, the resistance value of the stator windings can be reduced, and loss reduction and performance improvement of the rotating electrical machine can be achieved.

It is sectional drawing parallel to the axial direction of the rotary electric machine which has a stator by Embodiment 1 of this invention. It is sectional drawing perpendicular | vertical to the axial direction of the rotary electric machine which has a stator by Embodiment 1 of this invention. It is an enlarged view which shows only the outer side iron core and inner side iron core of the A section of FIG. It is an enlarged view of the B section of FIG. It is an enlarged view of the A section of FIG. 6 is a schematic diagram showing a state before a coil is arranged on the stator core of the stator according to Embodiment 1. FIG. FIG. 3 is a diagram showing a state where coils are arranged on the stator core of the stator according to the first embodiment. FIG. 3 is a diagram showing a stator according to the first embodiment. It is a figure which shows the state which press-fits the coil in the inner core of the stator by Embodiment 1. FIG. It is a figure which shows a mode that a coil falls in the recessed part of the inner core of the stator by Embodiment 1. FIG. It is a figure which shows the state before arrange | positioning a coil to the stator core of the stator by Embodiment 2. FIG. FIG. 10 is a diagram showing a state where coils are arranged on a stator core of a stator according to a second embodiment. FIG. 6 is a diagram showing a stator according to a second embodiment.

Hereinafter, preferred embodiments of a stator core and a stator of a rotating electric machine according to the present invention will be described with reference to the drawings.

Embodiment 1 FIG.
FIG. 1 is a diagram showing a cross section parallel to the axial direction of rotating electric machine 100 having stator 3 according to Embodiment 1 of the present invention. FIG. 2 is a view showing a cross section perpendicular to the axial direction of rotating electric machine 100 having stator 3 according to the first embodiment. 3 is an enlarged view of part A in FIG. 2 and shows only the stator core, and FIG. 4 is an enlarged view of part B in FIG. FIG. 5 is an enlarged view of part A of FIG.

In this specification, the terms “axial direction”, “radial direction”, “inner peripheral side”, and “outer peripheral side” are referred to as “axial direction”, “radial direction” of the stator, respectively, unless otherwise specified. "," Inner circumference side ", and" outer circumference side ".

Rotating electric machine 100 is a three-phase brushless motor. As shown in FIG. 1, the rotating electrical machine 100 is formed by a housing 2, a stator 3 accommodated in the housing 2, a rotor 4, and a rotating shaft 5. The rotating shaft 5 is fixed to the housing 2 in a state where both ends are rotatably supported by

bearings

7 and 8 fixed to the housing 2. The rotor 4 is fixed to the rotating shaft 5. The stator 3 is fixed to the inner wall of the housing 2 so as to surround the rotor 4. In FIG. 1, the output end 5a side of the rotating shaft 5 is the front side of the rotating electrical machine 100, and the opposite side is the rear side. The rotating electrical machine 100 is not limited to three phases, and may be five or more phases.

The rotating electrical machine 100 includes an inverter circuit (not shown), and the inverter circuit switches the current to be passed through the windings of each phase of the stator 3 in accordance with the phase of the rotor 4. Thereby, the inverter circuit controls the rotational speed and torque of the rotor 4. A rotation angle sensor 70 that detects the phase of the rotor 4 is disposed on the rear side of the rotation shaft 5.

The rotor 4 is a field of the rotating electrical machine 100, and is attached to a cylindrical rotor core 40 made of iron, which is a ferromagnetic material, and an outer peripheral surface of the rotor core 40 as shown in FIG. The plurality of permanent magnets 41 are formed.

The stator 3 is an armature of the rotating electrical machine 100, and is disposed on the outer peripheral side of the rotor 4 with a constant gap from the rotor 4 as shown in FIG. The stator 3 is formed by a stator core 30 and a stator winding 51. The stator core 30 includes an annular outer iron core 30a that is a back yoke portion, and an annular inner iron core 30b that is fitted inside the outer iron core 30a. The outer iron core 30 a and the inner iron core 30 b are formed by laminating a plurality of substantially circular thin electromagnetic steel plates in the axial direction of the rotating electrical machine 100.

As shown in FIG. 3, the inner iron core 30b has a plurality of teeth 31 arranged radially. Triangular protrusions 38 are formed at the outer peripheral ends of the teeth 31. On the other hand, the outer iron core 30a is formed with a plurality of V-grooves 37 that open to the inner peripheral side. The number of V grooves 37 in the outer iron core 30a is the same as the number of teeth 31 in the inner iron core 30b. When the outer iron core 30a is assembled to the inner iron core 30b, the convex portion 38 of the inner iron core 30b is engaged with the V groove 37 of the outer iron core 30a. Since the convex portions 38 of the inner iron core 30b are formed with inclined surfaces on both sides, the outer iron core 30a and the inner iron core 30b are connected by causing the inclined surfaces to run along the inner wall of the V-groove 37 of the outer iron core 30a. It can be easily positioned.

As shown in FIG. 3, the inner peripheral sides of the plurality of teeth 31 of the inner iron core 30b are connected to each other. A slot portion 36 is formed by the side surfaces of a pair of adjacent teeth 31. As shown in FIG. 4, both

end portions

38 a and 38 b of the convex portion 38 of the inner iron core are located on the inner side of the teeth from the extended lines of both side surfaces 39 a and 39 b of the tooth 31, respectively. Moreover, the recessed part 50 is each formed between the both

side surfaces

39a and 39b of each teeth 31, and the both ends 38a and 38b of the convex part 38, respectively. Each concave portion 50 and both

side surfaces

39a and 39b of the tooth 31 are connected by a smooth curve that bends gently, and has a shape without an edge portion.

As shown in FIG. 5, a stator winding 51 is arranged in each slot portion 36 of the inner iron core 30b. The stator winding 51 is formed by four coils 51A to 51D. The number of coils is not limited to four. The stator 3 is formed by press-fitting the outer iron core 30a on the outer peripheral side of the inner iron core 30b on which the stator winding 51 is disposed.

Since the stator core 30 is cylindrical, each tooth 31 is formed radially. For this reason, the cross section of the slot part 36 formed by a pair of adjacent teeth 31 in the direction perpendicular to the axis has a trapezoidal shape. In order to dispose the stator winding 51 at a high density in the trapezoidal slot portion 36, the cross section in the direction perpendicular to the axis of each of the coils 51A to 51D is trapezoidal.

The trapezoidal coils 51A to 51D are formed by applying plastic deformation to a general round cross-section coil or rectangular cross-section coil. In the first embodiment, since the cross section of the slot portion 36 is trapezoidal, the cross sections of the coils 51A to 51D are trapezoidal. However, if the slot portion 36 is rectangular, the coils 51A to 51D are used. The cross section may be rectangular.

A resin insulation coating is applied to the surface of each coil 51A to 51D. However, since the insulation coating has low mechanical strength, it is insufficient to ensure insulation between the stator core 30 and the coils 51A to 51D. It is. Therefore, an insulating paper 52 is disposed between each of the coils 51A to 51D and the inner iron core 30b and the outer iron core 30a. Thereby, even if it is a case where the rotary electric machine 100 vibrates or the case where the expansion / contraction by temperature change generate | occur | produces, insulation can be ensured.

As shown in FIG. 1, the coils 51A to 51D are joined by a joining portion 56 on the outer side in the axial direction of the stator 3. For joining the coils 51A to 51D, for example, welding or brazing is used. The coils 51A to 51D arranged in the slot portions 36 are connected to the coils 51A to 51D arranged in other adjacent slot portions 36 across the teeth 31.

Next, the procedure for forming the stator 3 will be described with reference to FIGS. 6A to 6C. First, the insulating paper 52 is wound around the stator winding 51. One sheet of insulating paper 52 is wound from one side surface 51a of the stator winding 51 to the other side surface 51c and the outer surface 51d through the inner surface 51b. The starting point and the ending point when winding the insulating paper 52 are between the side surface 51a and the upper surface 51d. The winding direction of the insulating paper 52 is not limited to this. For example, the stator winding 51 may be wound from the other side surface 51c through the inner peripheral side bottom surface 51b to the one side surface 51a and the outer peripheral side upper surface 51d.

When the start point and the end point of the insulating paper 52 are overlapped, the thickness of the insulating paper 52 is increased, and the density of the stator windings 51 in the slot portion 36 is reduced. Therefore, a slight gap is generated between the start and end of winding of the insulating paper 52. Therefore, the insulation distance between the inner iron core 30b and the stator winding 51 is ensured by setting the winding start and the winding end of the insulating paper 52 to corner portions between the side surface 51a and the upper surface 51d of the stator winding 51. ing.

Next, as shown in FIG. 6A, a jig 53 is arranged on the outer peripheral side of each tooth 31 of the inner iron core 30b. V-grooves that engage with the convex portions 38 of the teeth 31 are formed at the connection portions between the jigs 53 and the teeth 31, and the jigs 53 are formed to extend the teeth 31. Yes. Then, the stator winding 51 is disposed between the adjacent jigs 53.

The coils 51A to 51D arranged in each slot are connected to the coils 51A to 51D arranged in the other slots via a coil end on the outer side in the axial direction of the stator 3 with a plurality of teeth 31 interposed therebetween. ing. Therefore, the coil ends of the coils 51A to 51D forming the stator winding 51 overlap each other as shown in FIG.

Next, as indicated by arrows in FIG. 6B, the stator windings 51 are pushed into the respective slot portions 36 of the inner iron core 30b. At this time, the coils 51A to 51D are pushed into the slot portion 36 of the inner iron core 30b in an overlapping state. In FIG. 6B, the pushing jig for the stator winding 51 is omitted.

Next, each jig 53 is removed from the inner iron core 30b. Then, as shown in FIG. 6C, the outer iron core 30a is press-fitted with the positions of the V-grooves 37 of the outer iron core 30a aligned with the convex portions 38 of the teeth 31 of the inner iron core 30b.

Next, the end of each coil 51A to 51D forming the stator winding 51 is connected. Thus, the stator 3 is completed.

Here, FIGS. 7A and 7B show a state of the coil 51A press-fitted into the slot portion 36. FIG. As shown in FIG. 1, the coil 51 </ b> A is connected to the coil 51 </ b> A disposed in the other slot portion 36 across the plurality of teeth 31. Therefore, when the coil 51A is pushed into the slot portion 36, it is press-fitted along the side surface of the tooth 31 while deforming the connected portion on the outer side in the axial direction of the stator 3. At this time, as shown in FIG. 7A, a pressing force F is applied from the coil 51 </ b> A to the side surface of the jig 53 and the side surface of the tooth 31.

At this time, if the radial width W of the recess 50 formed on both side surfaces of the inner iron core 30b is large, the coil 51A may fall into the recess 50 as shown in FIG. 7B. If the coil 51A falls into the recess 50, the insulating paper 52 covering the coil 51A may be damaged.

For this reason, the width W in the radial direction of the recess 50 is set to be equal to or less than half of the height H in the radial direction of the cross section of the coil 51A. Thereby, when the coil 51A is moved along the side surface of the jig 53 and further moved along the side surface of the tooth 31 via the concave portion 50, the coil 51A does not fall into the concave portion 50. Therefore, damage to the insulating paper 52 covering the coil 51A can be prevented.

Also, when the stator winding 51 is energized, the temperature of the coils 51A to 51D rises due to Joule heat. When the temperature at this time exceeds the heat resistance temperature of the insulating coating or the insulating paper 52, insulation deterioration occurs. A path that conducts from the coils 51A to 51D to the inner iron core 30b through the insulating paper 52 is one of the heat dissipation paths. However, if the recess 50 is present, an air layer is interposed between the coils 51A to 51D and the teeth 31, so that heat dissipation is reduced. Here, the width W of the concave portion 50 is set to be equal to or less than half the height H of the coil 51A, and the air layer is made small, thereby suppressing a decrease in heat dissipation.

The stator core 30 is formed by laminating thin plates obtained by processing electromagnetic steel plates by pressing, and the shapes of the teeth 31 and the slot portions 36 described above can be obtained by pressing. At this time, the slot portion 36 and the convex portion 38 at the tip of the tooth 31 cannot be formed together by a single press process. Therefore, the processing of the slot portion 36 and the processing of the convex portion 38 at the tip of the tooth 31 must be divided into two times.

When the convex portion 38 at the tip of the tooth 31 is processed first and then the slot portion 36 is processed, a load is applied to the previously processed convex portion 38 and the convex portion 38 is deformed when the slot portion 36 is pressed. There is a case. Since the convex portion 38 is a fitting surface between the outer iron core 30a and the inner iron core 30b, when the convex portion 38 is deformed, there is a case where press fitting cannot be performed in the step of press-fitting the inner iron core 30b into the outer iron core 30a. Further, there arises a problem that a gap is generated in the fitting surface after press-fitting, the magnetic resistance is increased, the characteristics of the rotating electrical machine are deteriorated, and the roundness of the iron core after press-fitting is deteriorated. For this reason, the deformation of the convex portion 38 is prevented by processing the slot portion 36 first and then processing the convex portion 38 at the tip of the tooth 31.

Since the cross section in the radial direction of the slot portion 36 is substantially rectangular, it is pressed with the same rectangular mold. At this time, if the corners of the quadrangular shape have a shape without a fillet, a sharp point is generated in the mold, so that the durability of the mold is significantly lowered. Therefore, a fillet of an appropriate size is provided at the corner of the slot portion 36. The coils 51A to 51D arranged in the slot portion 36 also have rounded corners, so that even when a fillet is provided at the corner of the slot portion 36, the coils 51A to 51D are arranged. It will not be an obstacle.

Next, the convex portion 38 is processed so as to divide the previously processed slot portion 36. At this time, if the convex portion 38 is processed at a shallow angle with respect to the processing surface of the previously formed slot portion 36, an elongated sharp protrusion is formed on one iron core divided by the convex portion 38. Since the elongated protrusions are easily deformed during processing, a press-fitting failure occurs in the step of press-fitting the inner iron core 30b into the outer iron core 30a. For this reason, the processing surface is arranged so that the processing end of the convex portion 38 intersects at an angle as close to a right angle as possible with respect to the processing surface of the slot portion 36 so as not to generate an elongated protrusion. As described above, when the machining ends of the projections 38 are intersected at an angle close to a right angle with respect to the machining surface of the slot portion 36, corners are formed at the intersections of both machining surfaces.

Note that the stator core 30 of the present invention is divided into two parts, an outer core 30a and an inner core 30b. Then, when forming the iron core by pressing the thin steel sheet, both the inner core 30b is processed on the inner peripheral side and the outer core 30a is processed on the outer peripheral side. The method of processing is used. This method has an advantage that the roundness after press-fitting becomes good because the press-fitting surfaces of both the outer iron core 30a and the inner iron core 30b are simultaneously processed with the same mold.

There is also a method of processing the outer iron core 30a and the inner iron core 30b separately. In this case, since the processed end of the convex portion 38 can be rounded, it is possible to take measures against damage to the insulating paper without using the configuration of the present invention. However, when processed separately, the press-fitting surfaces of the outer iron core 30a and the inner iron core 30b are machined with different molds, and the roundness after press-fitting deteriorates due to shape variations between the molds. There is a case. In addition, there is a problem that the cost increases because the yield of the material is deteriorated.

Thus, the stator core 30 of the rotating electrical machine 100 according to the first embodiment is formed by the annular outer core 30a that is the back yoke portion and the annular inner core 30b that is fitted inside the outer core. . The outer iron core 30a has a plurality of V-grooves opened to the inner peripheral side, and the inner iron core 30b has a plurality of teeth 31 arranged radially. The plurality of teeth 31 are connected to each other on the inner peripheral side, and a plurality of slot portions 36 are formed by the side surfaces of the adjacent teeth 31. Each of the plurality of teeth 31 has a convex portion 38 that engages with the V groove 37 of the outer iron core 30a at the outer peripheral end, and the base of the convex portion 38 on both side surfaces of each tooth 31 has Each has a recess 50. Then, by connecting the recess 50 and the side surface of the tooth 31 with a gentle curve, no edge shape is formed on the side surface of the tooth 31 forming the slot portion 36.

Thereby, according to the stator core 30 of the rotating electrical machine 100 according to the first embodiment, the insulating paper 52 is damaged when the stator windings 51 covered with the insulating paper 52 are press-fitted into the slot portions 36. Can be prevented. Therefore, it is possible to prevent the stator winding 51 from being poorly insulated. Further, the insulating paper 52 can be thinned to increase the density of the coils 51A to 51D in the slot portion 36.

In the first embodiment, the surface magnet type rotor 4 in which the permanent magnet 41 is pasted on the surface of the rotor core 40 is used. However, the present invention is not limited to this. For example, the rotor core 40 may be a magnet-embedded rotor in which a hole for embedding a magnet is provided and a magnet is embedded in the hole. Moreover, in Embodiment 1, although the stator core 30 was formed by laminating | stacking an electromagnetic steel plate, it is not restricted to this. For example, a thin steel plate having an insulating coating on the surface may be laminated.

Embodiment 2. FIG.
In the stator 3 according to the first embodiment, the periphery of the stator winding 51 is covered with the insulating paper 52 and this is disposed in the slot portion 36 of the inner iron core 30b. 3 is different from the stator 3 of the first embodiment in that a part of the periphery of the stator winding 51 is not covered with the insulating paper 52. Other configurations are the same as those in the first embodiment.

8A to 8C are diagrams showing an assembling procedure of the stator 3 of the rotating electrical machine according to the second embodiment. In the second embodiment, as shown in FIG. 8A, first, the insulating paper 52 formed in a U-shape is disposed in the slot portion 36. Next, as shown in FIG. 8B, the stator winding 51 is pushed into the slot portion 36. At this time, the outer peripheral side of the stator winding 51 is not covered with the insulating paper 52.

Next, as shown in FIG. 8C, an insulating member 54 is disposed between the coil 51D on the outermost peripheral side of the stator winding 51 and the outer iron core 30a, and the outer iron core 30a is press-fitted into the inner iron core 30b. For the insulating member 54, thick insulating paper or a resin molded product is used. The insulating member 54 may be inserted after the outer iron core 30a is press-fitted into the inner iron core 30b. Thus, in the stator 3 of the rotating electrical machine according to the second embodiment, since it is not necessary to cover the stator winding 51 with the insulating paper 52 in advance, the stator winding 51 can be easily incorporated into the slot portion 36. .

Here, the coils 51A to 51D pushed into the slot portion 36 try to return to the outer peripheral side by the spring back. For this reason, after the outer iron core 30a is press-fitted, the coils 51A to 51D may move to the outer peripheral side of the slot portion 36 and be biased. Then, a pressure is always applied between the outer coil 51D and the outer iron core 30a, and insulation may be impaired.

The stator 3 according to the second embodiment includes an insulating paper 52 that insulates between the stator winding 51 and the inner iron core 30b, and an insulating member 54 that insulates between the stator winding 51 and the outer iron core 30a. Therefore, only the insulating member 54 can be thicker than the insulating paper 52 and can have a large load resistance. Therefore, even if a pressure is applied between the outer coil 51D and the outer iron core 30a, insulation between the coil 51D and the outer iron core 30a can be ensured.

2 Housing, 3 Stator, 4 Rotor, 5 Rotating shaft, 7, 8 Bearing, 30 Stator iron core, 30a Outer iron core, 30b Inner iron core, 31 teeth, 36 slot part, 37 V groove, 38 convex part, 40 rotation Core iron, 41 permanent magnet, 50 recess, 51 stator winding, 51A-51D coil, 52 insulation paper, 53 jig, 54 insulation member, 100 rotating electrical machine.

Claims

An annular outer core that is the back yoke part,
A stator iron core of a rotating electric machine having an annular inner iron core fitted inside the outer iron core,
The outer iron core has a plurality of V-grooves opened to the inner peripheral side,
The inner iron core has a plurality of teeth arranged radially,
The plurality of teeth are connected to each other on the inner peripheral side to form a plurality of slot portions by the side surfaces of the adjacent teeth,
Each of the plurality of teeth has a convex portion that engages with the V-groove of the outer iron core, respectively, at an outer peripheral end.
Both end portions of each convex portion are arranged on the inner side of each tooth from an extension line on both side surfaces of each tooth,
Between the both end portions of each convex portion and both side surfaces of each tooth, a concave portion is formed, respectively.
The concave portions and both side surfaces of the teeth are connected by a smooth curve.
Stator core for rotating electrical machines.
The stator core of claim 1;
A coil and insulating paper disposed in each of the plurality of slot portions;
Stator for rotating electric machine.
The insulating paper is disposed between the coil and the inner wall of the slot portion,
An insulating member is disposed between the coil and the outer iron core.
The stator of the rotary electric machine according to claim 2.
The radial width of the plurality of recesses is
Less than half of the radial height of each coil;
The stator of the rotary electric machine according to claim 2 or 3.