WO2020121555A1

WO2020121555A1 - Method for producing stator for rotating electrical machine, and rotating electrical machine

Info

Publication number: WO2020121555A1
Application number: PCT/JP2019/020620
Authority: WO
Inventors: 雄也平田; 源三岩城; 和雄西濱; 敦阿部
Original assignee: 株式会社日立産機システム
Priority date: 2018-12-13
Filing date: 2019-05-24
Publication date: 2020-06-18
Also published as: TWI739145B; JP2020096468A; JP7057745B2; TW202023148A; KR20210039423A; CN112840540A; JP7057745B6

Abstract

Provided are: a method for producing a rotating electrical machine stator which makes it possible to increase the efficiency of a rotating electrical machine and easily smooth out the inner-circumferential surface of a magnetic wedge so as to form the same cylindrical lateral surface as does the inner-circumferential surface of the stator core.　A method for producing a stator 3 of a rotating electrical machine, the method having: a first step for filling an opening 11 of a slot 8 of a stator core 7 with a mixture 17 which contains a magnetic powder 15 and an uncured or partially cured resin 16; a second step for smoothing out the inner-circumferential surface of the mixture 17 so as to form the same cylindrical lateral surface as does the inner-circumferential surface of the stator core 7 by using a flexible sheet 18 positioned along the inner-circumferential surface of the stator core 7; and a third step for forming a magnetic wedge 14 by curing the resin 16 while the inner-circumferential surface of the mixture 17 is in a smoothed state.

Description

Method of manufacturing stator of rotating electric machine and rotating electric machine

The present invention relates to a method for manufacturing a stator of a rotary electric machine and a rotary electric machine.

The rotating electric machine includes a rotating shaft, a rotor fixed to the outer peripheral side of the rotating shaft, and a stator arranged apart from the outer peripheral side of the rotor. The stator includes a stator core and coils inserted in a plurality of slots formed on the inner peripheral side of the stator core. Each slot is roughly divided into a storage part for housing the coil and an opening part that opens to the inner peripheral surface of the stator core. Conventionally, it has been known to provide a magnetic wedge made of a mixture containing magnetic powder and a resin at the opening of each slot. As a result, the high-frequency magnetic flux flows along the inner peripheral surface of the stator core and the inner peripheral surface of the magnetic wedge, so that the high-frequency magnetic flux is prevented from leaking from the stator side to the rotor side. Therefore, the efficiency of the rotary electric machine can be improved.

Patent Document 1 discloses a method for manufacturing the stator of the rotating electric machine described above. In this manufacturing method, the mixture containing the magnetic powder and the semi-cured resin is filled in the openings of the plurality of slots by using an injection cylinder having an outer diameter dimension slightly smaller than the inner diameter dimension of the stator core. Then, the resin is cured to form a magnetic wedge.

Japanese Patent Laid-Open No. 61-026453

However, the above-mentioned conventional technology has the following problems. In the method for manufacturing the stator of the rotating electric machine of Patent Document 1, since there is a difference between the inner diameter of the stator core and the outer diameter of the injection cylinder, the inner peripheral surface of the magnetic wedge has the same circumference as the inner peripheral surface of the stator core. Not a face. Therefore, the leakage of high frequency magnetic flux from the stator side to the rotor side cannot be sufficiently suppressed. Further, it is necessary to change the outer diameter dimension of the injection cylinder according to the inner diameter dimension of the stator core.

The present invention has been made in view of the above matters, and easily equalizes the inner peripheral surface of the magnetic wedge so that the inner peripheral surface of the stator core has the same cylindrical side surface, thereby increasing the efficiency of the rotating electric machine. This is one of the challenges.

Apply the configuration described in the claims to solve the above problems. The present invention includes a plurality of means for solving the above problems. To give an example thereof, a stator core, coils inserted in a plurality of slots formed on the inner peripheral side of the stator core, and A method of manufacturing a stator of a rotary electric machine, comprising: a plurality of magnetic wedges, each of which is provided in an opening portion of each of the plurality of slots that open to an inner peripheral surface of a stator core, and includes a magnetic powder and a mixture containing a resin; And a first step of filling the mixture containing the resin in the uncured state or the semi-cured state into the openings of the plurality of slots, and a flexible sheet arranged along the inner peripheral surface of the stator core. The inner peripheral surface of the mixture filled with the openings of the plurality of slots and containing the magnetic powder and the resin in the uncured state or the semi-cured state is the same cylinder with respect to the inner peripheral surface of the stator core. There is a second procedure for leveling the side surface and a third procedure for curing the resin to mold the magnetic wedge in a state where the inner peripheral surface of the mixture is leveled.

According to the present invention, the inner peripheral surface of the magnetic wedge can be easily leveled with the inner peripheral surface of the stator core so as to have the same cylindrical side surface, and the efficiency of the rotating electric machine can be improved.

Note that issues, configurations, and effects other than the above will be clarified by the following explanation.

It is a radial direction sectional view showing the structure of the rotary electric machine in one embodiment of the present invention. It is a partial expanded sectional view showing the structure of the stator of the rotary electric machine in one embodiment of the present invention. 3 is a flowchart showing a procedure of a method for manufacturing a stator of a rotary electric machine according to an embodiment of the present invention. FIG. 6 is a cross-sectional view showing a state in which an insulating material and a coil are inserted into a slot of the stator core according to the embodiment of the present invention. FIG. 3 is a radial cross-sectional view showing a seat arranged along the inner peripheral surface of the stator core in the embodiment of the present invention. It is a perspective view showing how to wind the sheet in one embodiment of the present invention. FIG. 6 is a cross-sectional view showing a state where the inner peripheral surface of the mixture filled in the slots of the stator core is flattened using the sheet according to the embodiment of the present invention. FIG. 6 is a cross-sectional view showing a state where the inner peripheral surface of the mixture filled in the slots of the stator core is flattened by using the sheet according to the first modified example of the present invention and the magnetic powder is attracted to the inner peripheral surface side of the mixture. is there. FIG. 11 is a radial cross-sectional view showing a seat arranged along an inner peripheral surface of a stator core according to a second modified example of the present invention. It is a radial cross section showing the sheet arranged along the inner skin of a stator core in the 3rd modification of the present invention. It is a radial cross section showing the sheet arranged along the inner skin of a stator core in the 4th modification of the present invention. It is a radial cross section showing the sheet arranged along the inner skin of a stator core in the 5th modification of the present invention. It is a perspective view showing how to wind the sheet in the 6th modification of the present invention. It is a flowchart showing the procedure of the manufacturing method of the stator of the rotary electric machine in the 7th modification of this invention. It is a side view showing the jig arrange|positioned at the axial direction one side and the other side of the stator core in the 7th modification of this invention.

An embodiment of the present invention will be described with reference to the drawings.

1 is a radial cross-sectional view showing the structure of the rotary electric machine according to the present embodiment. FIG. 2 is a partially enlarged cross-sectional view showing the structure of the stator of the rotary electric machine according to this embodiment.

The rotating electrical machine according to the present embodiment is a squirrel-cage induction motor, and includes a rotating shaft 1, a rotor 2 fixed to the outer peripheral side of the rotating shaft 1, and a stator 3 arranged apart from the outer peripheral side of the rotor 2. Equipped with.

The rotor 2 is inserted into a rotor core 4 and a plurality of slots 5 formed on the outer peripheral side of the rotor core 4, and a plurality of conductors extending in the axial direction of the rotor core 4 (direction perpendicular to the plane of the paper in FIG. 1). The bar 6, an end ring (not shown) arranged on one axial side of the rotor core 4 and connecting one side end portions of the plurality of conductor bars 6, and a plurality of end rings arranged on the other axial side of the rotor core 4. An end ring (not shown) that connects the other end of the conductor bar 6 is provided. The rotor core 4 is composed of a plurality of electromagnetic steel plates laminated in the axial direction.

The stator 3 includes a stator core 7 and a coil 9 inserted into a plurality of slots 8 formed on the inner peripheral side of the stator core 7. The stator core 7 is composed of a plurality of electromagnetic steel plates laminated in the axial direction. The coil 9 has a portion inserted into the slot 8 and a portion (see FIG. 15 described later) protruding from the slot 8 to one side and the other side in the axial direction of the stator core 7. Then, when electric power is supplied to the coil 9, the stator 3 generates a rotating magnetic field to rotate the rotor 2 and the rotating shaft 1.

Each slot 8 is roughly divided into a storage portion 10 for housing the coil 9 and an opening portion 11 that opens to the inner peripheral surface of the stator core 7. Each slot 8 is a semi-open type, and is formed such that the width dimension of the opening 11 in the circumferential direction (the left-right direction in FIG. 2) of the stator core 7 is smaller than the width dimension of the storage section 10. An insulating material 12A (slot liner) is provided on the inner wall of the storage part 10 of each slot 8, and the insulating material 12B (sashiki) covers the coil 9 together with the insulating material 12A.

A plurality of teeth portions 13 are formed between the plurality of slots 8 of the stator core 7. Unless the magnetic wedge 14 described below is provided in the opening 11 of each slot 8, the magnetic flux density varies due to the difference in the magnetic permeability between the air and the teeth 13 existing in the opening 11 of the slot 8. Therefore, the high frequency magnetic flux leaks from the stator 3 side to the rotor 2 side, resulting in a loss. Therefore, in order to suppress such a loss and improve the efficiency of the rotary electric machine, a magnetic wedge 14 is provided in the opening 11 of each slot 8. The magnetic wedge 14 is made of a mixture 17 containing a magnetic powder 15 (specifically, iron powder, for example) and a resin 16, and the volume ratio of the magnetic powder 15 is, for example, 60%.

In the present embodiment, the magnetic wedge 14 is provided in the opening 11 of each slot 8 and a part of the housing 10. In other words, the magnetic wedge 14 is shaped so as to come into contact with the inner wall of the opening 11, the inner wall of the housing 10, and the

insulating materials

12A and 12B. This prevents the magnetic wedge 14 from coming off the slot 8 of the stator core 7 even if the magnetic attraction force of the rotor 2 acts.

Next, a method of manufacturing the stator of the rotary electric machine of this embodiment will be described. FIG. 3 is a flowchart showing the procedure of the method for manufacturing the stator of the rotary electric machine according to this embodiment.

In step S1, the insulating material 12A, the coil 9, and the insulating material 12B are inserted into each slot 8 of the stator core 7 in that order, and they are fixed with a varnish or the like (see FIG. 4).

Thereafter, in step S2, a resin sheet 18 having flexibility and water resistance is arranged along the entire inner peripheral surface of the stator core 7 (see FIG. 5). The sheet 18 has a quadrangular shape and is rolled into a cylindrical shape (specifically, for example, as shown in FIG. 6, two opposite sides are in contact with each other, and the first corner and the second corner are in contact with each other. And is wound so that the third corner and the fourth corner are in contact with each other).

Then, in step S3, the mixture 17 containing the magnetic powder 15 and the resin 16 in the uncured state or the semi-cured state is applied from one axial side of the stator core 7 to the openings 11 of the slots 8 and a part of the storage portion 10. Fill. At this time, if the mixture 17 protrudes from each slot 8 to the other axial side of the stator core 7, this mixture 17 is removed.

Then, in step S4, the inner peripheral surface of the mixture 17 filled in each slot 8 is removed by using the seat 18 (specifically, by applying a force to the seat 18 along the inner peripheral surface of the stator core 7). , The inner peripheral surface of the stator core 7 is leveled so as to have the same cylindrical side surface (see FIG. 7). At this time, if the mixture 17 protrudes from each slot 8 to one side or the other side in the axial direction of the stator core 7, this mixture 17 is removed.

After that, in step S5, the resin 16 is cured by heating to form the magnetic wedge 14. If the sheet 18 does not have heat resistance, the sheet 18 is removed before the resin 16 is cured. On the other hand, if the sheet 18 has heat resistance, the sheet 18 may be removed after the resin 16 is cured.

As described above, in the present embodiment, the inner peripheral surface of the magnetic wedge 14 can be leveled so as to have the same cylindrical side surface as the inner peripheral surface of the stator core 7. As a result, it is possible to suppress the high-frequency magnetic flux from leaking from the stator 3 side to the rotor 2 side and improve the efficiency of the rotary electric machine. Moreover, by using the flexible sheet 18, the inner peripheral surface of the magnetic wedge 14 can be easily leveled. Moreover, even if the inner diameter of the stator core 7 is changed, it can be easily dealt with.

In the above embodiment, the case where the resin 16 is a thermosetting type has been described as an example, but the present invention is not limited to this, and modifications can be made without departing from the spirit and technical idea of the present invention. For example, the resin 16 may be a heat melting type (that is, a resin that is hardened by cooling).

Further, in the above-described embodiment, the case where the magnetic wedge 14 is provided in the opening 11 of the slot 8 and a part of the storage portion 10 has been described as an example, but the present invention is not limited to this. It may be provided only in the opening 11. In addition, in the above-described embodiment, the case where each slot 8 is a semi-open type and the width dimension of the opening 11 is smaller than the width dimension of the storage portion 10 has been described as an example. Not limited to this, each slot 8 may be an open type, and the width dimension of the opening 11 may be the same as the width dimension of the storage unit 10.

In addition, although not particularly described in the above-described embodiment, the inner peripheral surface of the stator core 7 (in other words, the inner peripheral surface of the tooth portion 13) before the mixture 17 is filled in the opening 11 of each slot 8. A release agent may be applied to. After that, the resin sheet 18 may be attached to the inner peripheral surface of the stator core 7 using an adhesive. In this case, by removing the seat 18, the mixture adhering to the inner peripheral surface of the stator core 7 can be easily removed.

Further, in the above embodiment, the case where the resin sheet 18 is used to smooth the inner peripheral surface of the mixture 17 filled in the openings 11 of the plurality of slots 8 has been described as an example, but the present invention is not limited to this. Without departing from the spirit and technical idea of the present invention, modifications can be made. For example, as in the first modification shown in FIG. 8, a flexible magnet sheet 18A may be used to even out the inner peripheral surface of the mixture 17 filled in the openings 11 of the plurality of slots 8. In this modification, the magnet sheet 18A can be attached to the inner peripheral surface of the stator core 7 without using an adhesive. Further, the magnetic powder 15 can be attracted to the inner peripheral surface side of the mixture 17 by the magnetic force of the magnet sheet 18A. Then, with the inner peripheral surface of the mixture 17 being leveled and the magnetic powder 15 being brought close to the inner peripheral surface side of the mixture 17, the resin 16 can be cured to form the magnetic wedge 14. As a result, it is possible to suppress variations in magnetic permeability on the inner peripheral surface of the magnetic wedge 14. Therefore, it is possible to further suppress the high-frequency magnetic flux from leaking from the stator 3 side to the rotor 2 side, and further improve the efficiency of the rotating electric machine. Although the resin sheet 18 is used as in the above-described embodiment, an electromagnet or the like may be arranged inside the sheet 18 to achieve the same purpose as in the above-described first modification.

Further, in the above embodiment, the case where the seat 18 is arranged along the entire inner peripheral surface of the stator core 7 has been described as an example, but the present invention is not limited to this, and is within a range not departing from the spirit and technical idea of the present invention. Can be transformed with. It suffices if the seat 18 or 18A can be arranged so as to cover at least one slot 8, that is, along the inner peripheral surface of at least two teeth portions 13. Specifically, for example, as in the second modification shown in FIG. 9, the seat 18 or 18A is provided so as to cover the two slots 8, that is, along the inner peripheral surfaces of the three teeth portions 13. You may arrange. Further, for example, as in the third modification shown in FIG. 10, the seat 18 or 18A may be arranged so as to extend along a quarter of the inner peripheral surface of the stator core 7. Further, as in the fourth modification shown in FIG. 11, for example, the seat 18 or 18A may be arranged along the half of the inner peripheral surface of the stator core 7. Further, as in the fifth modification shown in FIG. 12, for example, the seat 18 or 18A may be arranged along the three quarters of the inner peripheral surface of the stator core 7. Then, while moving the sheet 18 or 18A, the inner peripheral surface of the mixture 17 filled in the opening 11 of each slot 8 may be leveled. In these modifications, even if the inner diameter of the stator core 7 changes, it is possible to easily cope with the change.

Further, in the above-described embodiment, as the winding method of the quadrangular sheet 18, two opposite sides are in contact with each other, the first corner and the second corner are in contact, and the third corner and the fourth corner are in contact with each other. Although the description has been made by taking the case where the corners are wound so as to come into contact with each other as an example, the present invention is not limited to this and can be modified without departing from the spirit and technical idea of the present invention. For example, as in the sixth modified example shown in FIG. 13, although the two opposite sides are in contact, the first corner and the second corner are not in contact, and the third corner and the fourth corner are in contact. The sheet 18 or 18A may be wound obliquely so as not to do so. Thereby, even if the inner diameter of the stator core 7 is changed, it can be easily dealt with.

Further, in the above-described embodiment, after the sheet 18 is arranged along the inner peripheral surface of the stator core 7, each slot 8 is filled with the mixture 17 from one axial side of the stator core 7, and the stator core 7 is inserted from each slot 8. The case where the mixture 17 protruding to the other side in the axial direction is removed has been described as an example, but the present invention is not limited to this, and modifications can be made without departing from the spirit and technical idea of the present invention. Such a modified example will be described with reference to FIGS. 14 and 15.

FIG. 14 is a flowchart showing the procedure of the method for manufacturing the stator of the rotary electric machine according to this modification.

In step S1, the insulating material 12A, the coil 9, and the insulating material 12B are inserted in that order into each slot 8 of the stator core 7, and they are fixed with a varnish or the like. Then, in step S6, for example, cylindrical jigs 19 are arranged on one side and the other side in the axial direction of the stator core 7, and the slots 8 are covered with these jigs 19 (see FIG. 15).

Then, in step S3, each slot 8 is filled from the inner peripheral side of the stator core 7 with the mixture 17 containing the magnetic powder 15 and the uncured or semi-cured resin 16. At this time, if the mixture 17 protrudes from each slot 8 to the inner peripheral side of the stator core 7, the mixture 17 protruding is removed.

After that, in step S2, the seat 18 or 18A is arranged along the inner peripheral surface of the stator core 7. Then, in step S4, the inner peripheral surface of the mixture 17 filled in each slot 8 is leveled with the inner peripheral surface of the stator core 7 using the sheet 18 or 18A so as to have the same cylindrical side surface. Then, the resin 16 is cured by heating to form the magnetic wedge 14.

Also in this modification, the inner peripheral surface of the magnetic wedge 14 can be evened so as to have the same cylindrical side surface as the inner peripheral surface of the stator core 7. As a result, it is possible to suppress the high-frequency magnetic flux from leaking from the stator 3 side to the rotor 2 side and improve the efficiency of the rotary electric machine. Further, by using the flexible sheet 18 or 18A, the inner peripheral surface of the magnetic wedge 14 can be easily leveled. Moreover, even if the inner diameter of the stator core 7 is changed, it can be easily dealt with.

In the above description, a squirrel-cage induction motor (specifically, one including the rotor 2 having the conductor bar 6 and the end ring) has been described as an example of the rotary electric machine to which the present invention is applied, but the present invention is not limited to this. I can't. That is, the present invention may be applied to, for example, a permanent magnet synchronous motor (specifically, one including a rotor having a permanent magnet), or may be applied to a generator.

DESCRIPTION OF SYMBOLS 1... Rotating shaft, 2... Rotor, 3... Stator, 7... Stator core, 8... Slot, 9... Coil, 10... Storage part, 11... Opening part, 14... Magnetic wedge, 15... Magnetic powder, 16... Resin, 17 … Mixture, 18… Sheet, 18A… Magnet sheet

Claims

A stator core, coils inserted in a plurality of slots formed on the inner peripheral side of the stator core, and openings provided on the inner peripheral surface of the stator core, the slots respectively provided with magnetic powder and resin. In a method of manufacturing a stator of a rotating electric machine, which comprises a plurality of magnetic wedges made of a mixture,
A first step of filling the mixture containing the magnetic powder and the uncured or semi-cured resin into the openings of the plurality of slots;
A mixture containing the magnetic powder and the uncured or semi-cured resin filled in the openings of the plurality of slots using a flexible sheet disposed along the inner peripheral surface of the stator core. A second step of leveling the inner peripheral surface of the stator core with the inner peripheral surface of the stator core so as to have the same cylindrical side surface;
A third step of molding the magnetic wedge by curing the resin while the inner peripheral surface of the mixture is leveled.
The method for manufacturing a stator for a rotary electric machine according to claim 1,
The second step is to use the flexible magnet sheet arranged along the inner peripheral surface of the stator core to fill the openings of the plurality of slots to form the magnetic powder and the uncured state or semi-cured state. The inner peripheral surface of the mixture containing the resin in a state is leveled so as to be the same cylindrical side surface with respect to the inner peripheral surface of the stator core, and the magnetic powder is attracted to the inner peripheral surface side of the mixture,
The third step is characterized in that the resin is cured to form the magnetic wedge in a state where the inner peripheral surface of the mixture is leveled and the magnetic powder is brought close to the inner peripheral surface side of the mixture. And a method for manufacturing a stator of a rotating electric machine.
The method for manufacturing a stator for a rotary electric machine according to claim 1,
The said seat is arrange|positioned along all or one part of the inner peripheral surface of the said stator core, The manufacturing method of the stator of a rotary electric machine characterized by the above-mentioned.
The method for manufacturing a stator for a rotary electric machine according to claim 1,
The method for manufacturing a stator of a rotating electric machine, wherein the sheet is attached to an inner peripheral surface of the stator core using an adhesive.
A rotating shaft; a rotor fixed to the outer peripheral side of the rotating shaft; and a stator arranged apart from the outer peripheral side of the rotor,
The stator is provided with a stator core, a coil inserted into a plurality of slots formed on the inner peripheral side of the stator core, and openings of the plurality of slots opening on the inner peripheral surface of the stator core. And a plurality of magnetic wedges made of a mixture containing a resin,
The magnetic wedge is formed of a flexible sheet arranged along the inner peripheral surface of the stator core, and is filled in the openings of the plurality of slots to form the magnetic powder and the uncured or semi-cured state. A rotating electric machine, wherein the resin is cured and molded in a state where the inner peripheral surface of the mixture containing the resin is leveled so as to have the same cylindrical side surface as the inner peripheral surface of the stator core.
The rotary electric machine according to claim 5,
The magnetic wedge is filled in the openings of the plurality of slots by using a flexible magnet sheet arranged along the inner peripheral surface of the stator core, and is filled with the magnetic powder and the uncured state or the semi-cured state. In a state where the inner peripheral surface of the mixture containing the resin is leveled so as to have the same cylindrical side surface with respect to the inner peripheral surface of the stator core and the magnetic powder is brought close to the inner peripheral surface side of the mixture, A rotating electric machine characterized by being formed by curing resin.