WO2016035191A1

WO2016035191A1 - Rotating electric machine and method for manufacturing rotor core

Info

Publication number: WO2016035191A1
Application number: PCT/JP2014/073360
Authority: WO
Inventors: 野中　剛
Original assignee: 株式会社安川電機
Priority date: 2014-09-04
Filing date: 2014-09-04
Publication date: 2016-03-10

Abstract

[Problem] To increase the efficiency of a rotating electric machine. [Solution] A rotating electric machine 1 has: a stator core 21; a rotor core 31 provided with a plurality of laminated steel sheets 37 and having an axial direction dimension Lr shorter than that of the stator core 21; and a permanent magnet 32 buried in the rotor core 31 and having an axial direction dimension Lm shorter than that of the rotor core 31. The rotor core 31 is structured by laminating the steel sheets 37 having a hardenability and been heat-treated. The stator core 21 has a plurality of teeth 23b around which stator windings 25 are wound and a connection part 23a for connecting the ends of the teeth 23b on the inner circumferential side in a cylindrical shape.

Description

Rotating electrical machine, method of manufacturing rotor core

The disclosed embodiment relates to a method of manufacturing a rotating electrical machine and a rotor core.

Patent Document 1 describes a rotating electrical machine including a rotor core in which steel plates made of carbon steel or alloy steel having hardenability are stacked and the periphery of a magnet mounting hole is quenched. As a result, the rotor core is made strong and high speed rotation is realized. Also, in this rotating electrical machine, the rotor core is intentionally saturated by concentrating the magnetic flux generated from the magnet on the rotor surface, and the change in magnetic flux density near the rotating rotor core surface is reduced. The iron loss is kept low and high efficiency is achieved.

Japanese Patent No. 5256724

In the above prior art, further optimization of the device configuration is required in order to further increase the efficiency.

The present invention has been made in view of such problems, and an object of the present invention is to provide a rotating electrical machine and a method of manufacturing a rotor core capable of increasing efficiency.

In order to solve the above-described problems, according to one aspect of the present invention, a rotor core including a stator core and a plurality of stacked steel plates, the axial dimension of which is shorter than the stator core, and the rotor core And a permanent magnet having an axial dimension shorter than that of the rotor core is applied.

According to another aspect of the present invention, there is provided a method for manufacturing a rotor core of a rotating electrical machine, in which a heat-treated steel sheet is stamped and formed into a desired shape, and a plurality of the formed steel sheets are laminated. And a method for manufacturing a rotor core, which includes bonding an oxide film formed on the surface of the steel sheet by the heat treatment with an adhesive.

According to the present invention, it is possible to provide a rotating electrical machine and a method of manufacturing a rotor core that can be highly efficient.

It is an axial direction longitudinal cross-sectional view showing an example of the whole structure of the rotary electric machine which concerns on embodiment. It is a cross-sectional view orthogonal to the axial direction of the rotating electrical machine. It is a top view showing an example of the shape of the permanent magnet with which the magnet mounting hole provided in the rotor core and the magnet mounting hole were mounted | worn. It is a perspective view showing an example of composition of a rotor iron core. It is explanatory drawing showing an example of a structure of the boundary part of the steel plate which the rotor core which concerns on a comparative example adjoins. It is explanatory drawing showing an example of a structure of the boundary part of the steel plate which the rotor core which concerns on embodiment adjoins. It is process drawing showing an example of the manufacturing method of a rotor core. It is a figure showing an example of a general magnetic hysteresis curve. It is a cross-sectional view showing an example of the whole structure of the rotary electric machine of the modification provided with an open teeth type | mold stator. It is explanatory drawing showing an example of the state of a rotor when a field magnetic flux is small. It is explanatory drawing showing an example of the state of a rotor when a field magnetic flux is inside. It is explanatory drawing showing an example of the state of a rotor when a field magnetic flux is large.

Hereinafter, an embodiment will be described with reference to the drawings. In the following, for convenience of description of the configuration of the rotating electrical machine and the like, directions such as up, down, left, and right may be used as appropriate, but the positional relationship of each configuration of the rotating electrical machine and the like is not limited.

<1. Overall configuration of rotating electrical machine>
An example of the overall configuration of the rotating electrical machine 1 according to the present embodiment will be described with reference to FIGS. 1 and 2. The rotating electrical machine 1 is used as a motor or a generator.

As shown in FIGS. 1 and 2, the rotating electrical machine 1 has a stator 2 and a rotor 3. The stator 2 is provided on the inner periphery of the cylindrical frame 4. The rotor 3 is provided on the outer periphery of the shaft 10 and is disposed so as to face the stator 2 in the radial direction. A load side bracket 5 is provided on the load side (right side in FIG. 1) of the frame 4, and an antiload side bracket 6 is provided on the antiload side (left side in FIG. 1) of the frame 4. The shaft 10 is rotatably supported by a load side bearing 7 provided on the load side bracket 5 and an antiload side bearing 8 provided on the antiload side bracket 6.

An encoder 9 that detects the rotational position of the shaft 10 is provided at the end of the shaft 10 on the side opposite to the load. Note that the encoder 9 may not be provided. A bush 12 into which a lead wire 11 connected to an external power source (not shown) is inserted is attached to the outer periphery of the non-load side bracket 6. The lead wire 11 is connected to a connection portion (not shown) in which a plurality of stator windings 25 of the stator 2 are connected on the opposite load side of the stator 2.

In this specification, the “load side” refers to the direction in which a load is attached to the rotating electrical machine 1, that is, the direction in which the shaft 10 protrudes (right side in FIG. 1) in this example. The direction opposite to the load side, that is, the direction in which the encoder 9 is arranged with respect to the rotating electrical machine 1 in this example (left side in FIG. 1) is indicated.

<2. Detailed configuration of stator>
Next, an example of a detailed configuration of the stator will be described with reference to FIG. As shown in FIG. 2, the stator 2 includes a stator core 21 and a plurality (12 in the illustrated example) of the stator windings 25. The stator core 21 has a cylindrical outer stator core portion 22 provided along the inner peripheral surface of the frame 4 and an inner stator core portion 23 provided inside the outer stator core portion 22. . The inner stator core portion 23 includes a plurality (12 in the illustrated example) of teeth 23b arranged radially, and a connecting portion 23a that connects end portions on the inner peripheral side of the plurality of teeth 23b in a cylindrical shape. The outer stator core portion 22 and the inner stator core portion 23 are fixed by bolts 24 penetrating the outer peripheral end portions of the teeth 23 b of the inner stator core portion 23 and the outer stator core portion 22. Each stator winding 25 is wound around the teeth 23b of the inner stator core portion 23, and is formed between a plurality of teeth 23b adjacent to the circumferential direction and the outer stator core portion 22 (in the illustrated example). 12) in the slot 26.

<3. Detailed configuration of rotor>
Next, an example of the detailed configuration of the rotor will be described with reference to FIGS. As shown in FIG. 1 and FIG. 2, the rotor 3 includes a cylindrical rotor core 31 disposed with a magnetic gap inside the stator 2, and a plurality of rotor cores 31 provided inside the rotor core 31. And 20 permanent magnets 32 (in the illustrated example). As shown in FIG. 1, the axial dimension Lr of the rotor core 31 is shorter by a predetermined length than the axial dimension Ls of the stator core 21, and the axial dimension Lm of the permanent magnet 32 is equal to the rotor core 31. The predetermined length is set shorter than the axial dimension Lr. In this example, a so-called IPM (Internal Permanent Magnet) type configuration in which a plurality of permanent magnets 32 are embedded in the rotor core 31 is used. It is good also as a structure of a type | mold.

2 and 4, the rotor core 31 has a hole 36 provided with a plurality of convex portions 36a on the inner peripheral surface. On the other hand, the shaft 10 has a plurality of recesses 10a on the outer peripheral surface of the rotor mounting portion. The rotor core 31 is fixed to the outer peripheral surface of the shaft 10 by being fitted to the shaft 10 by shrink fitting or the like while fitting the convex portion 36a and the concave portion 10a. Further, between the load side bearing 7 and the end surface of the rotor core 31, and between the anti-load side bearing 8 and the end surface of the rotor core 31, the load side plate 15 and the anti load side plate 16 are respectively connected to the shaft 10. It is fixed to. The rotor core 31 is restricted from moving in the axial direction by the load side plate 15 and the anti-load side plate 16.

The rotor core 31 includes a plurality of magnet mounting holes 33 into which the plurality of permanent magnets 32 are inserted. As shown in FIG. 4, each magnet mounting hole 33 is provided so as to penetrate the rotor core 31 along the axial direction. Further, as shown in FIG. 3, each magnet mounting hole 33 has a substantially rectangular shape when viewed from the axial direction, but the two corners 33a on the outer peripheral side thereof have an arc shape (in other words, a curved surface shape when viewed from the axial direction). ). The permanent magnet 32 is formed in a substantially rectangular parallelepiped shape, and the shape seen from the axial direction is a substantially rectangular shape, but the two outer peripheral corners 32a corresponding to the corners 33a of the magnet mounting hole 33 are seen from the axial direction. It is formed in an arc shape. The permanent magnet 32 is inserted into the magnet mounting hole 33 and fixed with an adhesive or the like. The curved end surface on the outer peripheral side of the permanent magnet 32 mounted in the magnet mounting hole 33 and the planar side surfaces on both sides in the circumferential direction are curved end surfaces on the outer peripheral side of the magnet mounting hole 33 and the planar end surfaces on both sides in the circumferential direction. Touch the side. A gap 33 b is formed between the planar end surface 32 b on the inner peripheral side of the permanent magnet 32 and the end surface on the inner peripheral side of the magnet mounting hole 33.

As shown in FIGS. 2 and 3, the plurality of permanent magnets 32 embedded in the plurality of magnet mounting holes 33 includes two N poles or S poles having the same polarity, as viewed from the axial direction. The permanent magnets 32 are arranged in the rotor core 31 in such a manner that the permanent magnets 32 form a V-shaped pair projecting radially inward, and the opposite magnetic poles of the same polarity are alternately varied in the circumferential direction. As a result, a plurality (ten in this example) of magnetic pole portions 34 of N poles and S poles having different polarities are formed in the circumferential direction of the rotor core 31.

In the rotor 3 of the present embodiment, the angle between the two permanent magnets 32 arranged in a V shape so that the magnetic flux generated from the permanent magnet 32 in each magnetic pole portion 34 is concentrated on the surface of the rotor 3. Is designed to be sufficiently narrow. As a result, the rotor core 31 between the two permanent magnets 32 is intentionally saturated with magnetic flux, and the change in magnetic flux density in the portion near the surface of the rotating rotor core 31 is reduced. Designed to keep iron loss low.

As shown in FIG. 4, the rotor core 31 is formed by laminating a plurality of steel plates 37 punched and formed in a desired shape in the axial direction. Adjacent steel plates 37 are bonded together by an adhesive 38 (see FIG. 5A described later). As the steel plate 37, a steel plate having hardenability such as carbon steel and alloy steel is used. In the present embodiment, the entire steel plate 37 is quenched, and the plurality of steel plates 37 are stacked to form the rotor core 31 that is heat-treated on the entire surface including the inside.

In addition, instead of laminating the steel plates 37 that have been quenched as described above, the steel plates that have not been heat-treated may be laminated and then quenched by, for example, high-frequency heating. Moreover, it is good also as a structure by which the heat processing was given to one part instead of the whole rotor core 31. FIG. In this case, the part to be partially heat-treated includes, for example, a surface portion of the rotor core 31 and a region that is easily broken by stress due to the centrifugal force of the permanent magnet 32. As shown in FIG. 3, the region that is easily broken is, for example, a peripheral region 31 a around the outer periphery of the magnet mounting hole 33, a region 31 b between adjacent magnet mounting holes 33 arranged in a V shape, and the like. Further, the heat treatment applied to the rotor core 31 is not limited to quenching, and may be annealing (annealing) performed for removing strain due to work hardening, for example. Moreover, the steel plate 37 is not limited to the steel plate which has hardenability, You may use a normal electromagnetic steel plate.

<4. Configuration of the boundary between steel plates>
Next, an example of the configuration of the boundary between the steel plate and the steel plate will be described with reference to FIGS. 5A and 5B. FIG. 5A shows a rotor core 41 of a comparative example. In the rotor core 41 of this comparative example, a general electromagnetic steel sheet 47 is laminated. In general, the magnetic steel sheet 47 is rolled and annealed in the final step, processed to a prescribed thickness, and then subjected to an insulating film treatment. The insulating film 47a thus formed is formed with a thickness sufficient to block the eddy current flowing between the electromagnetic steel sheets 47 (thicker than the oxide film 37a). A gap 49 is generated between the adjacent electromagnetic steel sheets 47 according to the flatness of the surface of the steel sheet 47, but insulation is ensured by the insulating coating 47a, so that the gap 49 is not filled with an adhesive or the like. In the annealing process for softening the electromagnetic steel sheet 47, the surface of the electromagnetic steel sheet 47 is not oxidized, so that it is heated in a vacuum and slowly cooled. For this reason, since processing time becomes long and the apparatus for evacuating a heating installation etc. are needed, cost may increase.

FIG. 5B shows the rotor core 31 of this embodiment. As shown in FIG. 5B, the steel plate 37 has an oxide film 37a formed by quenching on its surface. Since this oxide film 37a is very thin, the insulating property may be low. Therefore, there is a possibility that the insulating property of the oxide film 37a may be impaired at a portion where the steel plate 37 and the steel plate 37 are in contact with each other due to vibration or the like during operation of the rotating electrical machine 1. Therefore, in the present embodiment, the adhesive 38 is filled in the gap 39 generated between the adjacent steel plates 37 due to unevenness (fine irregularities) on the surface of the steel plate 37. The adhesive 38 is made of, for example, a resin and has an insulating property. This adhesive 38 bonds the oxide films 37a of the adjacent steel plates 37 together. Thereby, while the adhesive agent 38 becomes a shock absorbing material, it can suppress the vibration of the steel plates 37, and can maintain the insulation property which is not inferior to the insulating film 40 of the comparative example for a long time. In addition, the steel plate 37 does not have a final annealing step and is a quenching step, so it does not need to be slowly cooled and may be rapidly cooled. Moreover, since the oxide film 37a is intentionally generated, it is not necessary to make the heating equipment vacuum. Furthermore, there is no insulation coating treatment. For this reason, the processing time can be greatly shortened and the cost can be reduced.

In addition, as a method of bonding the oxide films 37a of the steel plates 37 adjacent to the rotor core 31 with the adhesive 38, for example, the adhesive 38 is dropped on the steel plate 37, and the steel plate 37 is rotated at a high speed and bonded by centrifugal force. The first method (spread coating) in which the agent 38 is spread as a liquid film and applied to the steel plate 37, the second method in which the adhesive 38 is sprayed and applied to the steel plate 37 from a spray nozzle, and the impregnating adhesive as the adhesive 38 The lower half of the rotor core 31 is immersed in a bath of impregnating adhesive 38 at a shallow depth, and the adhesive 38 is sucked up by capillarity. And a third method for infiltrating the water.

<5. Manufacturing method of rotor>
Next, an example of a method for manufacturing the rotor 3 will be described with reference to FIG. As shown in FIG. 6, in the manufacturing process of the rotor core 31, first, the steel plate 37 is quenched. Next, the quenched steel plate 37 is stamped and formed into a desired shape (a shape including the magnet mounting hole 33 and the hole 36) with a press machine or the like. The order of the quenching process and the punching process may be reversed. Next, the rotor core 31 is completed by laminating a plurality of formed steel plates 37 and bonding and integrating the oxide films 37a formed on the surface of the steel plate 37 by quenching with an adhesive 38. On the other hand, in the manufacturing process of the rotor 3, first, the load side plate 15 is pressed into the shaft 10 and integrated. Next, the rotor core 31 is assembled to the shaft 10 integrated with the load side plate 15. Next, the permanent magnet 32 is attached to the magnet attachment hole 33 of the rotor core 31 and bonded and integrated. Next, the anti-load side plate 16 is press-fitted into the shaft 10 and integrated. Next, the permanent magnet 32 is magnetized. Thereby, the rotor 3 is completed.

<6. Effects of the embodiment>
As described above, the rotating electrical machine 1 according to the present embodiment includes the stator core 21, the rotor core 31, and the permanent magnet 32. The axial dimension Lr of the rotor core 31 is set shorter than the axial dimension Ls of the stator core 21, and the axial dimension Lm of the permanent magnet 32 is set shorter than the axial dimension Lr of the rotor core 31. Yes. Thereby, the following effects are obtained.

That is, with respect to the rotation of the rotor 3, the magnetic path resistance returning from the rotor core 31 to the rotor core 31 through the stator core 21 is small in the portion where the teeth 23b are present, and the portion where the teeth 23b are not present (the portion of the slot 26). ) To increase. Due to this fluctuation, eddy current loss and hysteresis loss occur in the rotor core 31. At this time, in the present embodiment, a steel plate such as carbon steel or alloy steel having poor hysteresis characteristics is used as the steel plate 37 of the rotor core 31 as compared with a general electromagnetic steel plate. A corresponding increase in hysteresis loss becomes a problem. FIG. 7 is a diagram illustrating an example of a general magnetic hysteresis curve.

At this time, by making the size relationship of the axial direction as follows: stator core 21> rotor core 31> permanent magnet 32, the magnetic path resistance in the portion where there is no tooth 23b can be reduced, and the fluctuation of the magnetic path resistance can be reduced. Can be small. As a result, ΔB and ΔH in the hysteresis curve of FIG. 7 can be reduced, and the iron loss generated in the rotor core 31 can be reduced. Thereby, since the iron loss (hysteresis loss) which generate | occur | produces in the rotor core 31 can be reduced, the rotary electric machine 1 can be made highly efficient.

In this embodiment, in particular, at least a part of the rotor core 31 is subjected to heat treatment (quenching in the above example). Thereby, since the intensity | strength of the rotor core 31 can be improved by quench hardening, high speed rotation is attained. Therefore, the output of the rotating electrical machine can be increased.

In this embodiment, in particular, the rotor core 31 is configured by laminating steel plates 37 having hardenability and heat-treated. Thereby, since each steel plate 37 which comprises the rotor iron core 31 becomes high intensity | strength by quenching hardening, the intensity | strength of the rotor iron core 31 can be improved significantly.

In the present embodiment, in particular, the stator core 21 includes a plurality of teeth 23b around which the stator winding 25 is wound, and a connecting portion 23a that connects the inner peripheral end of the teeth 23b in a cylindrical shape. Have. Thereby, there exists the following effect. That is, the connecting portion 23a can further reduce the magnetic path resistance in the portion where the tooth 23b is not present (the slot 26 portion), and can further reduce the fluctuation of the magnetic path resistance. As a result, since the iron loss (hysteresis loss) generated in the rotor core 31 can be reduced, the rotating electrical machine 1 can be further improved in efficiency.

In the present embodiment, in particular, the steel plate 37 has an oxide film 37 a formed by heat treatment on the surface, and the oxide films 37 a of the steel plates 37 adjacent to the rotor core 31 are bonded to each other by an adhesive 38. . Thereby, the following effects are obtained.

That is, as described above, the oxide film 37a formed on the surface of the steel plate 37 in the quenching process is very thin and may have low insulation. Therefore, there is a possibility that the insulating property of the oxide film 37a may be impaired at a portion where the steel plate 37 and the steel plate 37 are in contact with each other due to vibration or the like during operation of the rotating electrical machine 1. Therefore, by filling the adhesive 38 between the oxide films 37a of the adjacent steel plates 37, vibrations between the steel plates 37 can be suppressed, and deterioration of the rust and the like of the oxide films 37a can be prevented. Thereby, it is possible to maintain the insulating property which is not inferior to the conventional insulating film for a long time. Further, it is not necessary to provide an insulating film on the steel plate 37 as described above. Therefore, since the insulating film treatment is unnecessary, the processing time can be greatly shortened and the cost can be reduced.

In the present embodiment, in particular, the rotor core 31 is provided with a magnet mounting hole 33 in which the outer corner 33 a has an arc shape, and the permanent magnet 32 corresponds to the corner 33 a of the magnet mounting hole 33. The corner 32a is formed in an arc shape. Thereby, since the stress concentration at the corner 33a on the outer peripheral side of the magnet mounting hole 33 can be reduced, the strength of the rotor core 31 against the centrifugal force can be improved. Therefore, further high speed rotation is possible.

Moreover, the manufacturing method of the rotor core 31 of the rotary electric machine 1 according to the present embodiment includes a step of stamping and forming the quenched steel plate 37 into a desired shape, a step of laminating the plurality of formed steel plates 37, and quenching. A step of bonding the oxide films 37a formed on the surface of the steel plate 37 by the treatment with an adhesive 38. Thereby, the following effects are obtained.

That is, a general electrical steel sheet used for a rotor core is rolled and annealed in the final process, processed to a specified thickness, and then treated with an insulating film. In the annealing process for softening the steel plate, the steel plate surface is not oxidized and heated in a vacuum and cooled slowly.

On the other hand, the steel plate 37 in the present embodiment does not have a final annealing process and is a quenching process, so it does not need to be slowly cooled and may be rapidly cooled. Moreover, since the oxide film 37a is intentionally generated, it is not necessary to evacuate the heating equipment. Furthermore, there is no insulation film treatment. For this reason, the processing time can be greatly shortened and the cost can be reduced. Therefore, an inexpensive rotor core 31 having high centrifugal force breaking strength can be realized.

In the present embodiment, in the step of bonding the oxide films 37a with the adhesive 38, the gap 39 between the stacked steel plates 37 is impregnated with the adhesive 38 (the above-described third method). Since air bubbles between the formed steel plates 37 can be removed, the insulation between the steel plates 37 can be enhanced.

<7. Modification>
The disclosed embodiments are not limited to the above, and various modifications can be made without departing from the spirit and technical idea thereof. Hereinafter, such modifications will be described.

In the above embodiment, the stator iron core 21 has the end portions on the inner peripheral side of the plurality of teeth 23b around which the stator winding 25 is wound connected to the cylindrical shape by the connecting portion 23a. It is good also as what is called an open teeth structure by which the slot opened toward the inner peripheral side is provided between teeth, without connecting the edge part of an inner peripheral side. An example of this modification is shown in FIG. In FIG. 8, illustration of the frame, the shaft, and the like is omitted.

(7-1. Overall structure of rotating electrical machine)
As shown in FIG. 8, the rotating electrical machine 1A of the present modification includes a stator 2A and a variable field structure rotor 3A. The stator 2A includes a stator core 21A having a plurality (12 in this example) of teeth 23A and a plurality (12 in this example) of stator windings 25A wound around the plurality of teeth 23A. . Each of the plurality of teeth 23A is fixed to the cylindrical stator core portion 22A by a bolt 24A. The plurality of teeth 23A have a plurality (12 in this example) of slots 26A that are open on the inner peripheral side between the teeth 23A, and the stator winding 25A wound around the teeth 23A is accommodated in the slot 26A. The Similarly to the rotating electrical machine 1 of the above embodiment, the axial dimension Lr of the rotor core 31A is shorter than the axial dimension Ls of the stator core 21A by a predetermined length, and the axial dimension Lm of the permanent magnet 32A is The axial length Lr of the rotor core 31A is set shorter than the predetermined length.

(7-2. Dimensions of stator)
The teeth 23A of the stator core 21A have a circumferential width Wt of 70% or more of the slot pitch Wp (Wt ≧ 0.7Wp) at the end on the inner peripheral side, or between the teeth at the end on the inner peripheral side. It is set to at least twice the distance Ws (Wt ≧ 2 Ws). With such a dimensional relationship, the circumferential width of the teeth 23A can be increased, and the inter-tooth distance Ws can be reduced. As a result, the fluctuation of the magnetic path resistance returning from the rotor core 31A to the rotor core 31A through the stator core 21A in the portion with and without the teeth 23A is further reduced, and the rotor core 31A of the rotor 3 The generated iron loss (hysteresis loss) can be reduced, and the efficiency of the rotating electrical machine 1A can be further increased.

(7-3. Configuration of rotor)
The rotor 3A includes a cylindrical rotor core 31A disposed with a magnetic gap inside the stator 2A, a cylindrical member 55 disposed inside the rotor core 31A, and the interior of the rotor core 31A. A plurality of (10 in this example) first permanent magnets 32A provided radially, and a plurality (10 in this example) second permanent magnets 56 provided along the circumferential direction on the outer peripheral surface of the cylindrical member 55; Is provided. The rotor core 31A is subjected to quenching at least in part. That is, similar to the rotor core 31 in the above embodiment, the hardened steel plate 37A is laminated after being quenched.

The plurality of first permanent magnets 32A are arranged in such a manner that N poles or S poles having the same polarity are opposed to each other in the circumferential direction, and the opposite magnetic poles having the same polarity are alternately changed in the circumferential direction. Has been placed. As a result, a plurality (ten in this example) of magnetic pole portions 34A of N poles and S poles having different polarities are formed in the circumferential direction of the rotor core 31A.

The cylindrical member 55 is fixed to the shaft 10 (not shown). The rotor core 31A is provided so as to be rotatable relative to the cylindrical member 55 by a rotation mechanism (not shown). The rotor 3A rotates the rotor core 31A relative to the cylindrical member 55, and changes the position of the first permanent magnet 32A of the rotor core 31A with respect to the second permanent magnet 56 of the cylindrical member 55. It is possible to vary the field magnetic flux generated.

(7-4. Variable operation of field magnetic flux by rotor)
Next, an example of the variable operation of the field magnetic flux by the rotor 3A will be described with reference to FIGS.

FIG. 9 shows a state in which the field magnetic flux is small. In this state, the rotor core 31A and the cylindrical member 55 are at an angular position where the magnetic pole portion 34A and the second permanent magnet 56 having different polarities face each other in the radial direction. In this state, the magnetic flux of the magnetic pole portion 34A leaks to the second permanent magnet 56 side, so the field magnetic flux becomes small.

FIG. 10 shows a state in which the field magnetic flux is medium. In this state, the rotor core 31A and the cylindrical member 55 are at an angular position where the magnetic pole portion 34A and the intermediate position between the two second

permanent magnets

56 and 56 face each other in the radial direction. In this state, since the magnetic flux of the magnetic pole portion 34A leaking to the second permanent magnet 56 side is reduced, the field magnetic flux is medium.

FIG. 11 shows a state where the load torque is large. In this state, the rotor core 31A and the cylindrical member 55 are at angular positions where the polarities of the magnetic pole portion 34A and the second permanent magnet 56 coincide. In this state, the magnetic flux of the magnetic pole portion 34A leaking to the second permanent magnet 56 side is almost eliminated, and the magnetic flux of the magnetic pole portion 34A is strengthened by the second permanent magnet 56, so that the field magnetic flux becomes maximum.

According to this modification described above, the same effect as the above embodiment is obtained. Further, for example, since the field magnetic flux can be changed according to the magnitude of the load torque, the efficiency of the rotating electrical machine 1A can be further increased.

In addition, in the above description, when there are descriptions such as “vertical”, “parallel”, and “plane”, the description is not strict. That is, the terms “vertical”, “parallel”, and “plane” are acceptable in design and manufacturing tolerances and errors, and mean “substantially vertical”, “substantially parallel”, and “substantially plane”. .

In addition, in the above description, when there is a description such as “same”, “equal”, “different”, etc., in terms of external dimensions and size, the description is not strict. That is, the terms “identical”, “equal”, and “different” mean that “tolerance and error in manufacturing are allowed in design and that they are“ substantially identical ”,“ substantially equal ”, and“ substantially different ”. .

In addition to those already described above, the methods according to the above-described embodiments and modifications may be used in appropriate combination.

In addition, although not illustrated one by one, the above-described embodiments and modified examples are implemented with various modifications within a range not departing from the gist thereof.

DESCRIPTION OF

SYMBOLS

1,1A Rotating electric machine 21 Stator iron core 21A Stator iron core 23a Connection part 23b Teeth 23A Teeth 25 Stator winding 26 Slot 26A Slot 31 Rotor iron core 32 Permanent magnet 32a Corner part 33 Magnet mounting hole 33a Corner part 37 Steel plate 37a Oxidation Film 38 Adhesive Ws Distance between teeth Wt Teeth width Wp Slot pitch

Claims

A stator core,
A plurality of laminated steel plates, and a rotor core whose axial dimension is shorter than the stator core; and
A permanent magnet embedded in the rotor core and having an axial dimension shorter than that of the rotor core;
A rotating electric machine comprising:
The rotor core is
The rotating electrical machine according to claim 1, wherein at least a part is heat-treated.
The heat treatment
The rotating electrical machine according to claim 2, wherein the rotating electrical machine is quenching.
The rotor core is
The rotating electrical machine according to claim 2 or 3, wherein the steel sheet having hardenability and heat-treated is laminated.
The stator core is
A plurality of teeth around which the stator winding is wound;
5. The rotating electrical machine according to claim 1, further comprising: a connecting portion that connects the inner peripheral end of the teeth in a cylindrical shape.
The stator core is
Having a plurality of teeth formed with slots that are open toward the inner circumference between each other;
The teeth are
The width in the circumferential direction of the end portion on the inner peripheral side is 70% or more of the slot pitch, or more than twice the distance between the teeth on the end portion on the inner peripheral side. The rotating electrical machine according to any one of claims.
The steel plate
It has an oxide film formed on the surface by heat treatment,
The rotor core is
The rotating electrical machine according to any one of claims 1 to 6, wherein the oxide films of the adjacent steel plates are bonded together with an adhesive.
In the rotor core,
A magnet mounting hole having a circular arc at the outer peripheral corner is formed,
The permanent magnet is
The rotating electrical machine according to any one of claims 1 to 7, wherein a corner portion corresponding to the corner portion of the magnet mounting hole is formed in an arc shape.
A method of manufacturing a rotor core of a rotating electric machine,
Stamping the heat-treated steel sheet into a desired shape;
Laminating a plurality of the formed steel plates;
A method for manufacturing a rotor core, comprising bonding oxide films formed on the surface of the steel sheet by the heat treatment with an adhesive.
When bonding the oxide films with an adhesive,
The method for manufacturing a rotor core according to claim 9, wherein an adhesive is impregnated in a gap between the stacked steel plates.