WO2020116157A1

WO2020116157A1 - Stator of rotating electric machine and method of manufacturing stator of rotating electric machine

Info

Publication number: WO2020116157A1
Application number: PCT/JP2019/045359
Authority: WO
Inventors: 日野　徳昭; 公則澤畠; 永田　稔; 榎本　裕治; 雅寛堀; 松延　豊
Original assignee: 日立オートモティブシステムズ株式会社
Priority date: 2018-12-03
Filing date: 2019-11-20
Publication date: 2020-06-11
Also published as: JP7329918B2; JP2020092468A

Abstract

In a method of forming a stator winding by fitting segment coils inside a core, there is a problem in that it is not possible to determine whether connection is achieved because the inside thereof is invisible. Furthermore, there is a problem in that a long segment coil is difficult to input in a slot, and thus an insulation paper in the slot is damaged. In addition, there is a problem in that the core is divided, and therefore insulation between the cores cannot be secured at the divided portion of the core. According to the present invention, a stator of a rotating electric machine comprises: a first stator core having a first slot receiving a first segment coil; a second stator core having a second slot receiving a second segment coil; and an insulation member disposed between the first stator core and the second stator core, wherein an axial end surface of the first stator core is opposite to an axial end surface of the second stator core, an end portion of the first segment coil is disposed inside the first stator core, and an end portion of the second segment coil protrudes from the axial end surface of the second stator core.

Description

Rotating electric machine stator and method of manufacturing rotating electric machine stator

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

In order to realize a sustainable society these days, it is required to reduce the size and efficiency of rotating electrical machines to save energy, and in particular, for rotating electrical machines for moving bodies such as automobiles, weight reduction and downsizing are important. As such a rotating electric machine, for example, a rotor provided with a plurality of permanent magnets, a stator core provided to face the rotor, and a stator winding wound around the stator core are provided. In a rotary electric machine equipped with the permanent magnet, it is necessary to use a small stator having a small coil end portion that does not contribute to motor performance. As this manufacturing method, there is proposed one having a structure in which a stator core module in which a linear conductor of a coil is arranged in a slot and a mold end portion obtained by molding a coil end portion with an insulating member are joined (Patent Document 1).

Japanese Patent Laid-Open No. 2016-178783

In the technique of Patent Document 1, there is only one stator core, and the stator core is fitted on the outside of the core in the axial direction 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 has to be a straight line, so the coil end becomes longer by this straight line. Moreover, since the coil is divided on both sides in the axial direction of the core, there are two fitting portions, and the coil end becomes longer by that amount.

The present invention has been made in view of the above problems, and an object of the present invention is to achieve downsizing while ensuring connection reliability.

In order to solve the above problems, a stator of a rotating electric machine according to the present invention has a first stator core having a first slot for accommodating a first segment coil and a second slot for accommodating a second segment coil. A stator of a rotating electric machine comprising a second stator core and an insulating member arranged between the first stator core and the second stator core, wherein an axial end surface of the first stator core is , Facing the axial end surface of the second stator core, the end portion of the first segment coil is arranged in the first stator core, and the end portion of the second segment coil is in the axial direction of the second stator core. It projects from the end face.

According to the present invention, it is possible to provide a rotating electric machine that is downsized while ensuring connection reliability.

1 is an overall view of a rotary electric machine according to a first embodiment of the present invention. It is a perspective view of a split iron core of a stator concerning a 1st example of the present invention. 1 is an insulating shape of a stator according to a first embodiment of the present invention. It is a figure which shows the segment coil which concerns on the 1st Example of this invention. It is the figure which showed the fitting method of the segment coil which concerns on the 1st Example of this invention. It is a figure which shows the wiring method of the stator of the rotary electric machine which concerns on the 1st Example of this invention. It is a figure which shows the structure of the split stator which concerns on the 1st Example of this invention. It is a figure which shows the stator insulation of the conventional rotary electric machine. It is a figure which shows the insulating method in the stator of the rotary electric machine which concerns on the 1st Example of this invention. It is a figure which shows the structure of the split stator which concerns on the 2nd Example of this invention. It is a figure which shows the manufacturing method of the rotary electric machine which concerns on the 3rd Example of this invention. It is a figure which shows the manufacturing method of the rotary electric machine which concerns on the 3rd Example of this invention. It is a figure which shows the example of connection of the coil by the 3rd Example of this invention. It is a figure which shows the example of connection of the coil by the 3rd Example of this invention. It is a figure which shows the example of connection of the coil by the 3rd Example of this invention. It is a figure which shows the structure of the insulation member which concerns on the 1st Example of this invention. It is a figure which shows the structure of the split stator which concerns on the 2nd Example of this invention. It is a figure which shows the structure of the split stator which concerns on the 2nd Example of this invention.

Hereinafter, an example for carrying out the present invention (hereinafter referred to as an “example”) will be described with reference to the drawings. In all the drawings for explaining the embodiments, the same members are denoted by the same reference symbols in principle, and the duplicate description will be omitted as appropriate. The present invention is not limited to the examples described below.

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

In order to realize a sustainable society these days, it is required to reduce the size and efficiency of rotating electric machines to save energy, and especially for rotating electric machines for moving bodies such as automobiles, it is important to reduce their weight and size. As such a rotating electric machine, for example, a rotor provided with a plurality of permanent magnets, a stator core provided to face the rotor, and a stator winding wound around the stator core are provided. In a rotary electric machine equipped with the permanent magnet, it is necessary to use a small stator having a small coil end portion that does not contribute to motor performance. As a stator of such a rotary electric machine, one having a structure in which a stator core module in which a linear conductor of a coil is arranged in a slot and a mold end portion in which a coil end portion is molded by an insulator are joined together can be considered. However, in such a structure, since the fitting portion has to be a straight line, the coil end is lengthened by this straight line. Although a method of connecting the coil in the slot is also conceivable, such coil connection deteriorates the assemblability because there is no method for checking whether or not the fitting is made inside. Further, as a method of making a stator having a thick copper wire in a slot and a low electric resistance, a stator using a segment coil can be considered. However, if the core has an axial length of, for example, 150 mm or more, it is difficult to obtain the linear accuracy of a thin coil, and when the coil is inserted into the slot of the stator from the axial direction, 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. 1 is an overall view of a rotary electric machine according to a first embodiment of the present invention. As shown in FIG. 1, the rotary electric machine 1 includes a stator 20 and a rotor 30. The stator 20 is housed in the housing 12, the end brackets 11 are arranged at both ends of the housing 12, and support the shaft 70 via bearings 71. The rotor 30 is attached to the shaft 70. The rotor 30 is composed of a rotor core 300 and a magnet 4.

FIG. 2 is a perspective view of a split core of the stator according to the first embodiment of the present invention. As shown in FIG. 2, in the present embodiment, the stator 20 is divided in the axial direction, and the insulating member 5 is arranged on the abutting surface 9 of the core therebetween. The stator core 200 is provided with a slot 21 into which a coil is inserted, and is divided into two

stator blocks

20A and 20B in the axial direction. The insulating member 5 is provided on the abutting surfaces 9 of the

stator blocks

20A and 20B.

Here, as a method of applying the insulating member 5 to the

stator blocks

20A and 20B, there are, for example, powder coating and electrostatic coating. Alternatively, the resin may be integrally molded with the core. FIG. 3 shows an insulating shape of the stator according to the first embodiment of the present invention. The integral molding is a method of molding the insulating member 5 by putting the stator core 200 in a mold which is slightly larger than the stator core 200 and has substantially the same shape, and injecting a thermoplastic resin into the gap. As a result, the

stator block

20A or 20B can be provided with the insulating member 5 having the shape shown in FIG. 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. The insulating member 5 is preferably thin, and preferably 1 mm or less.

FIG. 4 is a diagram showing a segment coil according to the first embodiment of the present invention. A segment coil 6A and a segment coil 6B molded in a U shape as shown in FIG. 4 are inserted into the stator blocks 20A and 20B from opposite sides in the axial direction, respectively. The tip of the segment coil 6A is processed into a concave shape, and the tip of the segment coil 6B is processed into a convex shape. The segment coil is inserted across the slots, and 4 to 10 coils are inserted in one slot. For example, in the case of the stator core of FIG. 2, there are 48 slots 21, and if four segment coils 6A are inserted in 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 iron core and the segment coil.

FIG. 5 is a diagram showing a segment coil fitting method according to the first embodiment of the present invention. All the segment coils are fitted and electrically connected as shown in FIG. 5 in the vicinity of the abutting surfaces 9 of the stator block 20A and the stator block 20B.

FIG. 6 is a diagram showing a method of connecting the stator according to the first embodiment of the present invention. In FIG. 6, only the coils for one phase of the three-phase motor are shown. In FIG. 6, the solid line shows the segment coil 6A on the front side of the paper, and the double line shows the segment coil 6B on the back side of the paper. For example, in the serial circuit (1), the segment coil 6A is inserted into the stator block 20A from the front side of the drawing across the second layer of the first slot and the first layer of the fourth slot. The segment coil 6B inserted from the other side of the drawing is located in the fourth 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 the abutment of the stator block. The other end of the segment coil 6B is inserted in the second layer of the 7th slot and connected to the coil of the next segment coil 6A. By repeating this process once around the stator core, a winding is formed by so-called wave winding in the stator coil. The series circuit (2) to the series circuit (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 has a length up to the vicinity of the abutting surface 9 of the stator block A, and the end portion thereof has a depth that can be visually confirmed from the lower side of the drawing. The coil 6B is inserted in the core block 20B, and the end portion of the segment coil 6B projects from the butt end surface of the stator block 20B. With such a structure, before the segment coils 6A and 6B are fitted to each other, the positions of the coils can be measured in detail, and the suitability of the fitting can be determined in advance. Further, after the cores are brought into contact with each other, the connecting portion of the coil is fixed so that the fitting does not come off. This makes it possible to provide a more reliable motor.

In this embodiment, the abutting surfaces 9 of the stator blocks 20A and 20B are entirely covered with insulation. This is to secure an insulation creepage distance between the coil and the core on the split surface of the core. Hereinafter, the reason why the creepage distance must be secured will be described with reference to FIG.

FIG. 8 is a view showing the stator insulation of the conventional rotating electric machine. In the conventional rotary electric machine, an insulating paper 51 is inserted into the slot of the stator core 200, and the segment coil 6 is housed in the insulating paper 51. In this case, the axial end face of the core and the segment coil 6 are insulated by the insulating paper 51. However, when the dust 8 on the surface of the insulating material absorbs moisture due to moisture or the like, the insulation resistance may decrease. When the leakage current continues to flow from the coil to the core, the surface of the material deteriorates due to local discharge, and finally a conductive path (track) is formed, which causes dielectric breakdown of the surface. This is called tracking. In order to avoid this tracking, the insulating paper 51 is generally longer than the iron core 200 by about 5 mm as indicated by the insulating creepage distance 50. If this length is short, it will cause insulation deterioration due to tracking.

According to the construction method in which separate divided cores are butted against each other, the distance between the segment coil 6 of the enamel wire and the iron core 200 at the butted surface 9 of the core is only the thickness of the insulating paper 51. Normally, the insulation paper is about 0.5 mm, and therefore the creepage distance cannot be secured. Therefore, in this embodiment, as shown in FIG. 9, in order to secure a creepage distance between the stator 200 and the segment coil 6, the surface of the core is also insulated. Thus, the creepage distance from the segment coil to the stator core can include the distance from the slot in the direction perpendicular to the axis that insulates the core surface. Therefore, it is possible to insulate the rotary electric machine in which the core, the coil, and the insulating member are divided in the axial direction.

As described above, in this embodiment, since it is possible to confirm whether or not the fitting is performed inside, it is possible to reduce the defective rate of manufacturing. Further, in the conventional motor, if the core has an axial length of, for example, 150 mm or more, it is difficult to obtain the linear accuracy of the thin coil, and when the axial insertion into the slot of the stator, the insulating paper is often torn or misaligned. Therefore, there is a drawback that the motor manufacturing method becomes difficult. In this embodiment, since the insulating paper is not used, the manufacturability of the motor is improved. In addition, in the conventional motor, 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 end face of the core by that amount. In order to avoid breakage when bending this segment coil, a margin was required for this straight line portion, and the coil end could not be shortened by that length. In the stator of the rotating electric machine shown in this example, the surface of the core is also insulated, so that the creepage distance from the segment coil to the stator core is the direction perpendicular to the axis where the slot is insulated from the surface of the core. Since the distance can be included, the coil end can be shortened.

Although the insulating member 5 is formed on the entire surface of the core end surface in this embodiment, the insulating member 5 on the core end surface is insulated within a certain distance in the direction perpendicular to the axis from the slot in consideration of the creepage distance. If so, the same effect can be obtained.

Further, in the present embodiment, the example in which the insulating member 5 is integrally formed in the stator end surface and the slot is shown, but if the creepage distances are secured separately in the core end surface and the slot, the stator end surface Even if the insulating member 5 and the insulating member 5 in the slot 21 are separate bodies, the same effect can be obtained.

Further, as shown in FIG. 13, the protrusions 54 are made of integrally molded resin in the stator block 20A so that the stator blocks 20A are not displaced when they are stacked, and A recess may be formed to receive the protrusion 52. With such a configuration, the stator block is stabilized after the blocks are abutted with each other, so that it is possible to prevent the core from being displaced and the coil connection from being divided. It is also possible to make a coil guide 52 during injection molding so as to facilitate the positioning of the coil in the slot, or to make a coil partition 53 to avoid contact with an adjacent coil. This allows the stator to be assembled by a simple method. That is, since the core and the coil are divided near the fitting portion of the coil, the coil is shortened and the coil can be easily inserted from the axial direction. Further, the positions of the coils of the respective stator blocks can be correctly aligned immediately before the blocks are brought into contact with each other, so that the fitting is less likely to fail. Further, since the core end face in the vicinity of the coil is insulated, the insulation creepage distance in the vicinity of the fitting portion can be secured and the insulation can be easily secured. Further, since the preformed segment coil is inserted into the core, there is no bending work after assembling and the segment coil can be inserted to the end surface of the core, and the coil end can be shortened.

[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. 13 is a view showing the structure of the split stator according to the second embodiment of the present invention. The difference from the first embodiment is that the core is divided into three or more instead of two. The segment coil 6A is formed by stacking a stator block 20A and a stator block 20B, or a larger number of stator blocks. In the abutting surface 9 near the fitting portion of the coil, the short portion of the segment coil 6B projects from the axial end surface of the stator block 20C. In other words, the stator block 20B is divided into two stator blocks. As a result, it is possible to manufacture rotating electric machines having different stacking thicknesses and to share equipment. The effects of the rotary electric machine as a product can be similar to those of the first embodiment.

Further, as shown in FIG. 10, a stator block 20C may be arranged between the stator blocks 20A and 20B. The butt surface 9 is provided at two places, and the segment coil 6C to be inserted into the stator 20C has a linear shape and has a fitting portion at both ends, but the stator can be assembled in the same manner. Further, as shown in FIG. 15, it may be configured to be fitted inside the stator 20C. In this case, since there are two types of segment coils, the segment coil 6B and the segment coil 6C, it is possible to manufacture with 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]
11A and 11B are views showing a method of manufacturing a rotary electric machine according to the third embodiment of the present invention. By exchanging the stator blocks 20A and 20D in common with the stator block 20B, a stator of another rotating electric machine having different torque and voltage specifications can be manufactured. The rotary electric machine can change the connection by changing the lead wire or the modified coil 63. For example, as shown in FIGS. 12A, 12B and 12C, FIG. 12A shows a delta connection, FIG. 12B shows a star connection, and FIG. 12C shows a parallel connection. By changing such connections, it is possible to change the voltage/current specifications of the motor. Further, by changing the product thickness in the axial direction, motors having different torque specifications can be obtained. By using such a method, it is possible to make a larger number of rotary electric machines capable of developing a wide variety of products with a small amount of equipment.

DESCRIPTION OF SYMBOLS 1... Rotating electric machine, 4... Magnet, 5... Insulation member, 6... Segment coil, 8... Dust, 9... Core abutting surface, 11... End bracket, 12... Housing, 20... Stator, 20A... Stator block A , 20B... Stator block B, 20C... Stator block C, 21... Slot, 30... Rotor, 50... Insulating creepage distance, 51... Insulating paper, 52... Coil guide, 53... Coil partition, 54... Protrusion, 61 ... Crossover wire, 62... Lead wire, 63... Deformed coil, 70... Shaft, 71... Bearing, 200... Stator core, 300... Rotor core

Claims

A first stator core having a first slot for housing a first segment coil;
A second stator core having a second slot for accommodating the second segment coil;
A stator of a rotating electric machine having a rotating shaft, comprising: an insulating member arranged between the first stator core and the second stator core,
The rotation axis direction end surface of the first stator core faces the axis direction end surface of the second stator core,
An end of the first segment coil is disposed within the first stator core,
An end portion of the second segment coil is a stator of a rotating electric machine that protrudes from an axial end surface of the second stator core.
The stator of the rotating 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 core via the third stator core,
The said insulating member is a stator of a rotary electric machine arrange|positioned between the said 3rd stator core and the said 4th stator core.
A first stator core having a first slot for housing a first segment coil;
A second stator core having a second slot for accommodating the second segment coil;
A third stator core having a third slot for accommodating a third segment coil, the third stator core being disposed between the first stator core and the third stator core;
A stator of a rotating electric machine having a rotating shaft, comprising: an insulating member arranged between the first stator core and the third stator core and between the second stator core and the third stator core. hand,
End faces of the first stator core in the axial direction of the rotating shaft face axial end faces of the second stator core and the third stator core,
An end of the first segment coil is connected to one end of the third segment coil in the first stator core or the third stator core,
A stator of a rotating electric machine, wherein an end portion of the second segment coil is connected to the other end of the third segment coil in the second stator core or the third stator core.
A stator for a rotating electric machine according to any one of claims 1 to 3, wherein:
The said insulating member is a stator of a rotary electric machine arrange|positioned at both surfaces of the end surface in the axial direction of the said 1st stator core and the said 2nd stator core.
A stator for a rotating electric machine according to any one of claims 1 to 4, comprising:
The said insulating member is a stator of the rotary electric machine formed so that the axial direction end surface of the said 1st stator core or the said 2nd stator core may be covered.
A stator for a rotating electric machine according to any one of claims 1 to 5, wherein:
The said insulating member is a stator of a rotary electric machine which has a slot insulating part formed along the surface which forms the said 1st slot or the said 2nd slot.
The stator of the rotating electric machine according to claim 6,
The said insulating member is a stator of a rotary electric machine with which the part which contacts the end surface of the said 1st stator core, and a slot insulation part are integrally formed.
A stator for a rotating electric machine according to claim 6 or 7, wherein:
The insulating member has a guide portion for guiding the first segment coil on a surface of the slot insulating portion along the radial direction,
The guide portion is a stator of a rotary electric machine that projects in the circumferential direction.
A stator of a rotating electric machine according to any one of claims 6 to 8,
A stator of a rotating electric machine, wherein the insulating member has a partition portion for partitioning the first segment coil or the second segment coil and another segment coil on a surface of the slot insulating portion along the radial direction. ..
A stator for a rotating electric machine according to any one of claims 1 to 8, wherein:
The insulating member includes a first insulating member formed on an end surface of the first stator core, and a second insulating member facing the first insulating member,
The stator of a rotary electric machine which has a fitting part for fitting the 1st insulating member and the 2nd insulating member mutually.
A stator of a rotating electric machine according to any one of claims 1 to 10,
The insulating member is a stator of a rotating electric machine, which is applied to the core by powder coating or electrostatic coating.
A stator of the rotating electric machine according to any one of claims 1 to 11,
A rotating electric machine including a rotor.
A first step of forming an insulating member on a part of an axial end surface of the first stator core, and inserting a first segment coil from the other surface to form a first core block;
A second step of forming an insulating member on a part of an axial end surface of the first stator core and inserting a second segment coil from the other surface to form a second core block;
A third step of butting the end surfaces of the first stator block and the second stator block on which the insulating members are formed, and fitting the first segment coil and the second segment coil; Of manufacturing a stator of a rotating electric machine having the following.
A first step of forming an insulating member on a part of an axial end surface of the first stator core and inserting a first segment coil from the other surface to form a first core block;
A second step of forming an insulating member on a part of an axial end surface of the first stator core and inserting a second segment coil from the other surface to form a second core block;
An insulating member is formed on a part of an axial surface of the third stator core, and a linear third segment coil is inserted to form a third core block.
A third step of butting the end surface of the first stator block on which the insulating member is formed and the end surface of the third stator block, and fitting the first segment coil and the third segment coil; ,
A fourth step of abutting the end surface of the second stator block on which the insulating member is formed and the end surface of the third stator block, and fitting the second segment coil and the third segment coil; A method for manufacturing a stator of a rotating electric machine, comprising: