JP7329918B2 - Stator for rotating electrical machine and method for manufacturing stator for rotating electrical machine - Google Patents

Description

TECHNICAL FIELD The present invention mainly relates to a stator of a rotary electric machine and a manufacturing method thereof.

Toward the realization of a sustainable society in recent years, there is a demand for compact and high-efficiency rotating electrical machines to save energy. In particular, it is important to reduce the weight and size of rotating electrical machines for moving bodies such as automobiles. As such a rotating electric machine, for example, a rotor having a plurality of permanent magnets, a stator core provided facing the rotor, and a stator winding wound around the stator core. In a rotating electric machine having permanent magnets, it is necessary to use a compact stator with small coil end portions that do not contribute to the performance of the motor. As a manufacturing method for this, there is proposed a structure in which a stator core module in which straight conductors of a coil are arranged in slots and a mold end portion in which a coil end portion is molded with an insulating member are joined (Patent Document 1).

JP 2016-178783

The technique disclosed in Patent Document 1 has a single stator core, and the axial outer side of the core is fitted with the coil of the mold end. As can be seen from the coil shape in FIG. 5 of Patent Document 1, the fitting portion must be straight, so the coil end is lengthened by this straight line. In addition, since the coil is split on both sides in the axial direction of the core, there are two fitting portions, and the length of the coil end is increased accordingly.

SUMMARY OF THE INVENTION An object of the present invention is to reduce the size while ensuring connection reliability.

In order to solve the above problems, a stator for a rotary electric machine according to the present invention has a first stator core having a first slot that accommodates a first segment coil, and a second slot that accommodates a second segment coil. A stator for a rotating electric machine having a rotating shaft, comprising a second stator core and an insulating member arranged between the first stator core and the second stator core, the stator comprising the first stator core faces the axial end face of the second stator core via an insulating member , the end of the first segment coil is disposed inside the first stator core, and the end of the second segment coil protrudes from the axial end face of the second stator core and connects to the end of the first segment coil in the first stator core, and the insulating member is formed on the axial end face of the first stator core. and a second insulating member formed on the axial end surface of the second stator core and facing the first insulating member, wherein the first insulating member and the second insulating member are mutually It has a fitting portion for fitting .

ADVANTAGE OF THE INVENTION According to this invention, the rotating electric machine which achieves size reduction while ensuring connection reliability can be provided.

1 is an overall view of a rotating electric machine according to a first embodiment of the present invention; FIG. 1 is a perspective view of a split core of a stator according to a first embodiment of the present invention; FIG. 4 is an insulating shape of the stator according to the first embodiment of the present invention; It is a figure which shows the segment coil based on 1st Example of this invention. It is the figure which showed the fitting method of the segment coil based on the 1st Example of this invention. FIG. 4 is a diagram showing a method of connecting the stator of the rotary electric machine according to the first embodiment of the present invention; It is a figure which shows the structure of the split stator based on 1st Example of this invention. It is a figure which shows the stator insulation of the conventional rotary electric machine. FIG. 4 is a diagram showing a method of insulating the stator of the rotary electric machine according to the first embodiment of the present invention; FIG. 5 is a diagram showing the structure of a split stator according to a second embodiment of the present invention; It is a figure which shows the manufacturing method of the rotary electric machine based on the 3rd Example of this invention. It is a figure which shows the manufacturing method of the rotary electric machine based on the 3rd Example of this invention. FIG. 10 is a diagram showing an example of coil connection according to a third embodiment of the present invention; FIG. 10 is a diagram showing an example of coil connection according to a third embodiment of the present invention; FIG. 10 is a diagram showing an example of coil connection according to a third embodiment of the present invention; It is a figure which shows the structure of the insulating member based on the 1st Example of this invention. FIG. 5 is a diagram showing the structure of a split stator according to a second embodiment of the present invention; FIG. 5 is a diagram showing the structure of a split stator according to a second embodiment of the present invention;

Hereinafter, examples for carrying out the present invention (hereinafter referred to as "embodiments") will be described with reference to the drawings. In principle, the same reference numerals are given to the same members in all the drawings for explaining the embodiments, and redundant explanations will be omitted as appropriate. It should be noted that the present invention is not limited to the examples described below.

Before describing the embodiments, the background or principle leading to the present invention will be described.

Toward the realization of a sustainable society these days, there is a demand for compact and high-efficiency rotating electrical machines to save energy. In particular, it is important to reduce the weight and size of rotating electrical machines for moving bodies such as automobiles. As such a rotating electric machine, for example, a rotor having a plurality of permanent magnets, a stator core provided facing the rotor, and a stator winding wound around the stator core. In a rotating electric machine having permanent magnets, it is necessary to use a compact stator with small coil end portions that do not contribute to the performance of the motor. A stator for such a rotating electric machine may have a structure in which a stator core module in which straight conductors of a coil are arranged in slots and a mold end portion in which a coil end portion is molded with an insulator are joined. However, in such a structure, since the fitting portion must be straight, the coil end is lengthened by this straight line. A method of connecting the coils within the slot is also conceivable, but such a coil connection deteriorates assembly because there is no method for confirming whether or not the coils are fitted inside. Moreover, a stator using segment coils can be considered as a method of making a stator with thick copper wires in slots and low electrical resistance. However, if the core has an axial length of, for example, 150 mm or more, it is difficult to achieve straight line accuracy for the thin coil, and when inserting the coil from the axial direction into the slots of the stator, the insulating paper is often torn or misaligned. becomes difficult.

The present embodiment has been made in view of the above problems.

[Example 1]
This embodiment will be described with reference to FIGS. 1, 2 and 3. FIG. FIG. 1 is an overall view of a rotating electrical machine according to a first embodiment of the invention. As shown in FIG. 1 , the rotating electrical machine 1 consists of a stator 20 and a rotor 30 . The stator 20 is housed in a housing 12 , and end brackets 11 are arranged at both ends of the housing 12 to support a shaft 70 via bearings 71 . A rotor 30 is attached to the shaft 70 . The rotor 30 is composed of a rotor core 300 and magnets 4 .

FIG. 2 is a perspective view of the split core of the stator according to the first embodiment of the present invention. As shown in FIG. 2, this embodiment has a structure in which the stator 20 is divided in the axial direction, and the insulating member 5 is arranged on the abutment surface 9 of the core between them. A stator core 200 is provided with slots 21 into which coils are inserted, and is axially divided into two stator blocks 20A and 20B. An insulating member 5 is applied to the abutment surfaces 9 of the stator blocks 20A and 20B.

Here, examples of methods for applying the insulating member 5 to the stator blocks 20A and 20B include powder coating and electrostatic coating. Alternatively, the resin may be integrally molded with the core. FIG. 3 shows the insulation shape of the stator according to the first embodiment of the present invention. Integral molding is a method in which the stator core 200 is placed in a mold that is slightly larger and has substantially the same shape as the stator core 200 , and the insulating member 5 is molded by injecting a thermoplastic resin into the gap between the molds. As a result, the insulating member 5 shaped as shown in FIG. 3 can be applied to the stator block 20A or 20B. If the insulating member 5 is applied to the core, the end face of the stator 20 and the inside of the slot 21 can be electrically insulated. It is preferable that the insulating member 5 is thin, and preferably 1 mm or less.

FIG. 4 is a diagram showing a segment coil according to the first embodiment of the invention. A U-shaped segment coil 6A and a segment coil 6B as shown in FIG. 4 are inserted into the stator blocks 20A and 20B from axially opposite sides. The distal end of the segment coil 6A is processed into a concave shape, and the distal end of the segment coil 6B is processed into a convex shape. The segment coils are inserted across the slots, and about 4 to 10 coils are inserted in one slot. For example, in the stator core of FIG. 2, there are 48 slots 21, and if four segment coils 6A are inserted into each slot, 96 segment coils 6A and 6B are required.

The stator block 20A and the stator block 20B may be impregnated with varnish, for example, for the purpose of integrally fixing the core and the segment coil.

FIG. 5 is a diagram showing a method of fitting segment coils according to the first embodiment of the present invention. All segment coils are fitted and electrically connected as shown in FIG.

FIG. 6 is a diagram showing a stator connection method according to the first embodiment of the present invention. FIG. 6 shows only one phase coil of a three-phase motor. In FIG. 6, the solid line indicates the segment coil 6A in front of the page, and the double line indicates the segment coil 6B in the back of the page. For example, in the series circuit (1), the segment coil 6A straddles the second layer of the first slot and the first layer of the fourth slot and is inserted into the stator block 20A from the front side of the paper. The segment coil 6B inserted from the other side of the paper is positioned in the No. 4 slot of the stator block 20B, and one ends of the segment coil 6A and the segment coil 6B are connected by fitting together with butting of the stator blocks. The other end of the segment coil 6B is inserted into the second layer of the 7th slot and connected to the coil of the next segment coil 6A. By repeating this process and making one turn around the stator core, the stator coil is wound by so-called wave winding. The series circuits (2) to (4) also form windings in the same manner to form a coil for four turns. The stator winding is completed by making them for three phases.

FIG. 7 is a diagram showing the structure of the split stator according to the first embodiment of the present invention. As shown in FIG. 7, one end of the segment coil 6A extends to the vicinity of the abutment surface 9 of the stator block A, and the terminal end thereof is deep enough to be visually confirmed from the bottom of the paper. A coil 6B is inserted into the core block 20B, and the end of the segment coil 6B protrudes from the abutting end face of the stator block 20B. By adopting such a structure, before the segment coils 6A and 6B are fitted together, the positions of the coils can be measured in detail, and it is possible to determine in advance whether or not fitting is possible. In addition, after the cores are joined together, the connection portion of the coil is fixed, so that the fitting will not come off. This makes it possible to provide a more reliable motor.

In this embodiment, the mating surfaces 9 of the stator blocks 20A and 20B are entirely covered with insulation. This is to secure an insulating creepage distance between the coil and the core at the split face of the core. The reason why the creepage distance must be ensured will be described below with reference to FIG.

FIG. 8 is a diagram showing stator insulation of a conventional rotary electric machine. A conventional rotary electric machine has a structure in which insulating paper 51 is inserted into slots of stator core 200 and segment coils 6 are accommodated therein. In this case, the axial end face of the core and the segment coil 6 are insulated by insulating paper 51 . However, when the dust 8 on the surface of the insulating material absorbs moisture or the like, the insulation resistance may decrease. If leakage current continues to flow from the coil to the core, localized electrical discharges will degrade the surface of the material, eventually creating tracks and dielectric breakdown of the surface. This is called tracking. In order to avoid this tracking, the insulating paper 51 is generally made longer than the iron core 200 by about 5 mm as indicated by the insulating creepage distance 50 . If this length is short, it may cause deterioration of insulation due to tracking.

In the method of butting and connecting separate split cores, the distance between the segment coil 6 of the enameled wire and the iron core 200 is only the thickness of the insulating paper 51 at the butting surface 9 of the core. Since the insulation paper is usually about 0.5 mm, the creepage distance cannot be ensured. Therefore, in this embodiment, as shown in FIG. 9, the surface of the core is also insulated in order to secure the creepage distance between the stator 200 and the segment coils 6 . As a result, the creepage distance from the segment coil to the stator core can also include the distance in the direction perpendicular to the axis where the core surface is insulated from the slots. Therefore, it is possible to insulate a rotary electric machine in which the core, the coil, and the insulating member are divided in the axial direction.

As described above, according to the present embodiment, it is possible to confirm whether or not the parts are fitted inside, so that the manufacturing defect rate can be reduced. In conventional motors, if the core has an axial length of, for example, 150 mm or more, it is difficult to obtain linear accuracy for thin coils, and when inserting the coil into the slots of the stator from the axial direction, the insulating paper is often torn or misaligned. Therefore, there is a drawback that the motor manufacturing method becomes difficult. In this embodiment, since insulating paper is not used, the manufacturability of the motor is improved. In conventional motors, the insulating paper requires a creepage distance of about 5 mm between the core and the coil to prevent dielectric breakdown due to tracking, and the paper protrudes from the core end face by that amount. In order to avoid tearing when bending the segment coil, this straight portion needs a margin, and the coil end could not be shortened by that length. In the stator of the rotary electric machine shown in this embodiment, the surface of the core is also insulated, so that the creepage distance from the segment coil to the stator core is reduced in the direction perpendicular to the axis along which the core surface is insulated from the slots. can be included, the coil end can be shortened.

In this embodiment, an example is shown in which the insulating member 5 is formed on the entire core end surface. If so, you get the same effect.

In this embodiment, the insulating member 5 is molded integrally with the stator end face and in the slot. Similar effects can be obtained even if the insulating member 5 and the insulating member 5 in the slot 21 are separate members.

Also, as shown in FIG. 13, the stator block 20A is integrally formed with resin projections 54 so that the divided stator blocks are not shifted when stacked, and the stator block B is provided with projections 54 on the stator block 20A. A recess may be made to receive the protrusion 52 . With such a configuration, the stator block is stabilized after the blocks are butted together, so that it is possible to avoid disconnection of the coil connection due to displacement of the core. Also, coil guides 52 can be made during injection molding to facilitate positioning of the coils in the slots, or coil dividers 53 can be made to avoid contact with adjacent coils. Thereby, the stator can be assembled by a simple method. That is, since the core and the coil are separated near the fitting portion of the coil, the coil is shortened and the coil can be easily inserted from the axial direction. In addition, since the positions of the coils of each stator block can be correctly aligned immediately before the blocks are brought together, fitting failure is less likely to occur. In addition, since the core end face near the coil is insulated, it is possible to secure the insulation creepage distance near the fitting portion, and it is easy to secure insulation. In addition, since the preformed segment coil is inserted into the core, there is no need for bending work after assembly, and the segment coil can be inserted up to the end face of the core, making it possible to shorten the coil end.

[Example 2]
A stator according to a second embodiment of the present invention will be described with reference to FIGS. 10, 14 and 15. FIG. FIG. 13 is a diagram showing the structure of the split stator according to the second embodiment of the present invention. The difference from Example 1 is that the core is divided into three or more instead of two. The segment coil 6A is formed by stacking stator blocks 20A and 20B, or more stator blocks. A short portion of the segment coil 6B protrudes from the axial end surface of the stator block 20C on the abutment surface 9 near the fitting portion of the coil. In other words, the stator block 20B is divided into two stator blocks. As a result, it is possible to manufacture rotating electric machines with different lamination thicknesses, and it is possible to share facilities. As for the effects of the rotating electric machine as a product, the same effects as in the first embodiment can be obtained.

Also, as shown in FIG. 10, a stator block 20C may be arranged between the stator blocks 20A and 20B. There are two abutting surfaces 9, the segment coil 6C to be inserted into the stator 20C has a linear shape, and the structure has fitting portions at both ends, but the stator can be assembled in the same manner. Further, as shown in FIG. 15, it may be configured to fit inside the stator 20C. In this case, since there are two types of segment coils, ie, the segment coil 6B and the segment coil 6C, it is possible to manufacture only two types of segment coils. In this case, the same effect can be obtained even if the structure is fitted inside the stator block 20A.

[Example 3]
11(a) and 11(b) are diagrams showing a method for manufacturing a rotating electric machine according to the third embodiment of the present invention. By sharing the stator block 20B and interchanging the stator blocks 20A and 20D, it is possible to manufacture stators for different rotating electric machines with different torque and voltage specifications. The rotary electric machine can change the wire connection by changing the lead wire and the deformed coil 63 . For example, as shown in FIGS. 12(a), (b) and (c), FIG. 12(a) is delta connection, FIG. 12(b) is star connection, and FIG. 12(c) is parallel connection. By changing such connections, the voltage and current specifications of the motor can be changed. Also, by changing the lamination thickness in the axial direction, it is possible to make a motor with different torque specifications. With such a method, it is possible to manufacture a large number of rotary electric machines with a small number of facilities.

REFERENCE SIGNS LIST 1 rotating electrical machine 4 magnet 5 insulating member 6 segment coil 8 dust 9 mating surface of core 11 end bracket 12 housing 20 stator 20A stator block A , 20B... Stator block B, 20C... Stator block C, 21... Slot, 30... Rotor, 50... Insulation creepage distance, 51... Insulating paper, 52... Coil guide, 53... Coil partition, 54... Projection, 61 ... Crossover wire 62 ... Lead wire 63 ... Irregular shaped coil 70 ... Shaft 71 ... Bearing 200 ... Stator core 300 ... Rotor core

Claims (13)

a first stator core having a first slot accommodating the first segment coil;
a second stator core having a second slot accommodating a second segment coil;
A stator for a rotating electric machine having a rotating shaft, comprising an insulating member arranged between the first stator core and the second stator core,
the axial end face of the first stator core faces the axial end face of the second stator core through the insulating member;
ends of the first segment coils are disposed within the first stator core;
an end of the second segment coil protruding from an axial end face of the second stator core and connected to an end of the first segment coil within the first stator core;
The insulating member includes a first insulating member formed on the axial end surface of the first stator core and a second insulating member formed on the axial end surface of the second stator core and facing the first insulating member. 2 insulating members,
A stator for a rotary electric machine , wherein the first insulating member and the second insulating member have fitting portions for fitting to each other . A stator for a rotary electric machine according to claim 1,
The second stator core is divided into a third stator core and a fourth stator core facing the axial end surface of the first stator core through the third stator core,
A stator for a rotary electric machine , further comprising another insulating member arranged between the third stator core and the fourth stator core. a first stator core having a first slot accommodating the first segment coil;
a second stator core having a second slot accommodating a second segment coil;
a third stator core having a third slot for accommodating a third segment coil and disposed between the first stator core and the second stator core;
a stator for a rotating electric machine having a rotating shaft, comprising insulating members arranged between the first stator core and the third stator core and between the second stator core and the third stator core, respectively . and
both end faces of the third stator core in the axial direction of the rotating shaft face axial end faces of the second stator core and the first stator core, respectively ;
an end of the first segment coil is connected to one end of the third segment coil within the first stator core or the third stator core;
an end of the second segment coil is connected to the other end of the third segment coil within the second stator core or the third stator core ;
The insulating member includes a first insulating member formed on the axial end surface of the first stator core, a second insulating member formed on the axial end surface of the second stator core, and the third insulating member formed on the axial end surface of the second stator core. a third insulating member formed on one axial end face of the stator core and facing the first insulating member; and a second insulating member formed on the other axial end face of the third stator core. and a fourth insulating member facing the
A stator for a rotary electric machine, wherein the first insulating member and the third insulating member and the second insulating member and the fourth insulating member each have a fitting portion for fitting to each other. A stator for a rotary electric machine according to any one of claims 1 to 3,
An axial end face of the first stator core opposite to the end face on which the first insulating member is formed, and an axial end face of the second stator core on which the second insulating member is formed. A stator for a rotary electric machine , further comprising separate insulating members disposed on the opposite end surface and the opposite end surface of the stator. A stator for a rotary electric machine according to any one of claims 1 to 4,
The stator of a rotary electric machine, wherein the insulating member is formed so as to cover an axial end surface of the first stator core or the second stator core. A stator for a rotary electric machine according to any one of claims 1 to 5,
The stator of a rotary electric machine, wherein the insulating member has a slot insulating portion formed along a surface forming the first slot or the second slot. A stator for a rotary electric machine according to claim 6,
The insulating member is a stator for a rotary electric machine in which a portion contacting an end surface of the first stator core and the slot insulating portion are integrally formed. A stator for a rotary electric machine according to claim 6 or 7,
The insulating member has a guide portion for guiding the first segment coil to a radial surface of the slot insulating portion,
The guide portion is a stator of a rotary electric machine that protrudes in a circumferential direction. A stator for a rotary electric machine according to any one of claims 6 to 8,
The insulating member has a partition portion for partitioning the first segment coil or the second segment coil from other segment coils on a radial surface of the slot insulating portion. . A stator for a rotary electric machine according to any one of claims 1 to 9 ,
The insulating member is a stator of a rotary electric machine, the core of which is coated with powder coating or electrostatic coating. a stator for a rotary electric machine according to any one of claims 1 to 10 ;
A rotating electric machine comprising a rotor. a first step of forming an insulating member on a part of an axial end face of the first stator core and inserting a first segment coil from the other face to form a first stator block;
a second step of forming an insulating member on a part of the axial end face of the second stator core and inserting the second segment coil from the other face to form a second stator block;
a third step of matching the end surfaces of the first stator block and the second stator block on which the insulating member is formed and fitting the first segment coil and the second segment coil; A method for manufacturing a stator for a rotating electric machine having a first step of forming an insulating member on a part of an axial end face of the first stator core and inserting a first segment coil from the other face to form a first stator block;
a second step of forming an insulating member on a part of the axial end face of the second stator core and inserting the second segment coil from the other face to form a second stator block;
a third step of forming an insulating member on a portion of the axial surface of the third stator core and inserting a linear third segment coil to form a third stator block;
a fourth step of matching the end face of the first stator block on which the insulating member is formed and the end face of the third stator block to fit the first segment coil and the third segment coil; and,
a fifth step of fitting the second segment coil and the third segment coil by abutting the end face of the second stator block on which the insulating member is formed and the end face of the third stator block; and a method for manufacturing a stator for a rotating electric machine.

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