JP3690067B2 - Permanent magnet rotating electric machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a permanent magnet rotating electrical machine.
[0002]
[Prior art]
Rotating electric machines are desired to be smaller, lighter and more efficient than before. For example, when it is used for an electric vehicle such as an electric vehicle, there is a demand for economical driving and an improvement in a driving distance per unit of battery. To that end, it is necessary to be small and light and highly efficient.
[0003]
As a small, lightweight and highly efficient rotating electrical machine, it is known that a permanent magnet rotating electrical machine using a permanent magnet as a magnetic flux generating means is optimal.
[0004]
Recently, by using rare earth magnets as permanent magnets, it has been attempted to ensure high magnetic flux density and improve efficiency.
[0005]
However, since rare earth magnets have high conductivity and low resistance, eddy currents are likely to occur, and conversely cause a reduction in efficiency.
[0006]
In order to solve this problem, eddy currents inside permanent magnets are reduced by alternately arranging conductive permanent magnets with high magnetic flux density, represented by rare earth magnets, and non-conductive permanent magnets in the rotor axis direction. Is described in JP-A-5-227686.
[0007]
[Problems to be solved by the invention]
However, since the technique described in the above publication uses a non-conductive permanent magnet in part, the utilization rate of the magnet is deteriorated and efficiency cannot be increased as compared with the case where only the conductive permanent magnet is used.
[0008]
Further, in the above technique, since the permanent magnet is composed of different materials, the rotating electric machine has to be configured on the basis of the material with low mechanical strength out of the two types of materials, and there is a problem that reliability is lowered.
[0009]
In view of the above, an object of the present invention is to provide a permanent magnet rotating electrical machine that can achieve high efficiency while reducing eddy current on the surface of a magnet.
[0010]
[Means for Solving the Problems]
The permanent magnet rotating electrical machine of the present invention is inserted into a plurality of permanent magnet insertion holes formed inside the rotor core, and has a mutually different polarity in the rotor circumferential direction with a space between each other in the rotor circumferential direction. The permanent magnets arranged in parallel to each other are made of conductive magnets, and the conductive unit magnets are arranged in the rotor so as to increase the electric resistance and reduce the eddy current generated on the surface. It is composed of a plurality of unit magnet groups arranged side by side in the circumferential direction, and the insulating member is interposed between the unit magnets by inserting the unit magnet formed with the insulating member into the permanent magnet insertion hole. .
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0012]
1 is a cross-sectional view of a permanent magnet rotating electrical machine, FIG. 2 is a plan view of the permanent magnet rotating electrical machine of FIG. 1, and FIG. 3 is a perspective view of a rotor.
[0013]
In this embodiment, the number of salient stator windings is 12 and the number of permanent magnet poles of the rotor is 8. However, the present invention can be applied to other salient poles and poles. Is possible.
[0014]
In the figure, a permanent magnet rotating electrical machine 1 includes a stator 2 and a rotor 3, and the stator 2 includes a stator core 4 and a stator winding 5.
[0015]
The rotor 3 is configured such that the conductive permanent magnets 6 that are divided in the rotation direction of the rotor 3 and configured of unit magnet groups having a magnet width τ _m1 are arranged to have different polarities in the circumferential direction. .
[0016]
That is, as shown in FIG. 3, a permanent magnet composed of a unit magnet group having N / S polarity and a conductive permanent magnet composed of a unit magnet group having S / N polarity are composed of a rotor core 7. It is inserted into the permanent magnet insertion hole 12 formed in the above, and is rotatably held by the end brackets 11 and 111 via the shaft 8 and bearings 10 and 101.
[0017]
Here, the frame 9 is shown on the outer periphery of the stator core 4, but the frame may be omitted if necessary.
[0018]
Here, when the magnet width of the unit magnet is τ _m1 and the interval between the stator winding salient poles 41 and 42 is τ _m , τ _m1 <τ _m .
[0019]
By adopting such a configuration, for example, the conductive permanent magnet 6 facing the stator winding salient poles 41 and 42 is formed of a plurality of unit magnets, so the surface area of each unit magnet is reduced. The electric resistance can be increased. For this reason, the eddy current due to the harmonic magnetic flux hardly flows and the loss due to the eddy current can be reduced.
[0020]
Therefore, even when a conductive permanent magnet having a high magnetic flux density typified by a rare earth magnet is used, a highly efficient rotating electrical machine can be realized, and a small, light, and highly efficient permanent magnet rotating electrical machine can be provided.
[0021]
In this example, the N · S or S · N unit magnet is inserted into the permanent magnet insertion hole 12 after being polarized (after magnetization). However, the unit magnet material is magnetized after insertion. May be. In this case, the effect of improving the operation of inserting the unit magnet material can be obtained.
[0022]
FIG. 4 shows another embodiment of the present invention.
[0023]
The difference from the embodiment of FIG. 2 is that the unit magnet is formed via an insulator 13.
[0024]
The insulator 13 may be inserted between the unit magnets, but if the unit magnet is filled and fixed together with an adhesive or resin, the unit magnet can be fixed and the insulator 13 can be fixed at the same time. An effect is obtained.
[0025]
According to the said structure, since a unit magnet is insulated by the insulator 13, an eddy current stops flowing between unit magnets, and the reduction of an eddy current loss can be aimed at further.
[0026]
In the above description, the insulator 13 is inserted or filled with an adhesive or the like. However, the insulator 13 may be formed on a unit magnet in advance by coating or the like. In this case, work steps such as insertion of the insulator 13 or filling with an adhesive or the like can be omitted, so that an effect of improving workability can be obtained.
[0027]
5 and 6 show another embodiment of the present invention.
[0028]
The difference from the embodiment of FIG. 2 is that the height h of the unit magnet located at the center of the unit magnet group is made different from the heights h1 and h2 of the unit magnets on both sides thereof.
[0029]
That is, FIG. 5 shows the height h1 of the unit magnets at both ends smaller than the height h of the two unit magnets at the center, and FIG. 6 shows the height h of the unit magnet at the center. On the other hand, the heights h1 and h2 are made smaller toward the end.
[0030]
According to the said structure, the effect that the shape of the electroconductive permanent magnet 6 can be easily formed, such as a substantially trapezoid and a substantially semicircle, by the selection of the height h of a unit magnet is acquired.
[0031]
Similarly, when a highly conductive permanent magnet such as rare earth is not used, it can be easily formed in a substantially trapezoidal shape or a substantially semicircular shape by selecting the height h of the unit magnet.
[0032]
In the above embodiment, the shape of the magnet insertion port 13 of the rotor core 7 and the shape of each unit magnet are substantially the same, but as shown in FIGS. 7 and 8, the permanent magnet insertion hole shown in FIG. 12 may be provided with an insulating space such as an insulator 13 or an air layer between the permanent magnet insertion hole 12 and the unit magnet.
[0033]
According to the above configuration, since the amount of magnetic flux at both ends of the conductive permanent magnet can be suppressed, an effect of reducing the cogging torque generated between the stator winding salient pole and the magnet can be obtained.
[0034]
FIG. 9 shows another embodiment of the permanent magnet rotating electrical machine of the present invention.
[0035]
The difference from FIG. 2 is that the width τ _m1 of the unit magnet at the center is different from the width τ _{m2 of the} unit magnets at both ends.
[0036]
That is, in FIG. 9, τ _m2 of the unit magnets at both ends is made smaller than the width τ _{m1 of the} four unit magnets at the center.
[0037]
According to the above configuration, the effect that the shape of the conductive permanent magnet 6 can be made closer to a trapezoidal shape or a semicircular shape can be obtained by changing the width τ _{m1 of the} unit magnet according to the position of the magnet.
[0038]
In the above description, the conductive permanent magnet 6 has been described as having a rectangular shape. However, the shape of the permanent magnet 6 is not particularly limited to a permanent magnet shape such as an arc shape or a star shape as shown in FIGS.
[0039]
Further, the same effect can be obtained even when the conductive permanent magnet is used in a configuration in which it is arranged on the surface of the rotor core.
[0040]
Further, the description has been given of the permanent magnet rotating electric machine having the permanent magnet rotor structure. However, the rotating electric machine is not limited to a rotating electric machine, and may be applied to a rotating electric machine using an outer rotation type and an inner rotation type rotor. is there.
[0041]
Furthermore, it can be applied not only to rotating electrical machines but also to linear motors and the like.
[0042]
【The invention's effect】
By configuring the conductive permanent magnet with a plurality of conductive unit magnet groups, a highly efficient permanent magnet rotating electrical machine can be obtained while reducing eddy currents on the magnet surface.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a permanent magnet rotating electric machine that constitutes an embodiment of the present invention.
2 is a plan view of the permanent magnet rotating electric machine of FIG. 1. FIG.
3 shows a perspective view of the permanent magnet rotor of FIG. 1. FIG.
FIG. 4 is a partial plan view of a permanent magnet rotating electric machine according to another embodiment of the present invention.
FIG. 5 is a partial plan view of a permanent magnet rotating electric machine according to another embodiment of the present invention.
FIG. 6 is a partial plan view of a permanent magnet rotating electric machine according to another embodiment of the present invention.
FIG. 7 is a partial plan view of a permanent magnet rotating electric machine that constitutes another embodiment of the present invention.
FIG. 8 is a partial plan view of a permanent magnet rotating electric machine according to another embodiment of the present invention.
FIG. 9 is a partial plan view of a permanent magnet rotating electric machine according to another embodiment of the present invention.
FIG. 10 is a partial plan view of a permanent magnet rotating electric machine according to another embodiment of the present invention.
FIG. 11 is a partial plan view of a permanent magnet rotating electric machine according to another embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Rotary electric machine, 2 ... Stator, 3 ... Rotor, 4 ... Stator core, 5 ... Stator winding, 6 ... Conductive permanent magnet, 7 ... Rotor core, 8 ... Shaft, 9 ... Outer frame, DESCRIPTION OF SYMBOLS 10,101 ... Bearing, 11, 111 ... End bracket, 12 ... Permanent magnet insertion hole, 13 ... Insulator, 41, 42 ... Stator winding salient pole.

Claims (5)

A stator having a plurality of stator salient poles wound with windings;
A rotor rotatably held by the stator with a rotation gap;
The rotor is
A rotor core in which a plurality of permanent magnet insertion holes are formed;
The permanent magnets are inserted into the plurality of permanent magnet insertion holes, and have permanent magnets arranged in a ring in the circumferential direction of the rotor so as to have different polarities in the circumferential direction of the rotor,
The permanent magnet is
It consists of a conductive magnet,
In order to increase the electrical resistance and reduce the eddy current generated on the surface, the conductive unit magnet is composed of a group of unit magnets arranged in parallel in the circumferential direction of the rotor ,
An insulating member is interposed between the unit magnets,
The permanent magnet rotating electrical machine according to claim 1, wherein the insulating member is formed on the unit magnet, and the unit magnet is interposed between the unit magnets by being inserted into the permanent magnet insertion hole . A stator having a plurality of stator salient poles wound with windings;
A rotor rotatably held by the stator with a rotation gap;
The rotor is
A rotor core in which a plurality of permanent magnet insertion holes are formed;
The permanent magnets are inserted into the plurality of permanent magnet insertion holes, and have permanent magnets arranged in a ring in the circumferential direction of the rotor so as to have different polarities in the circumferential direction of the rotor,
The permanent magnet is
It consists of a conductive magnet,
In order to increase the electrical resistance and reduce the eddy current generated on the surface, the conductive unit magnet is composed of a group of unit magnets arranged in parallel in the circumferential direction of the rotor,
An insulating member is interposed between the unit magnets,
The insulating member is formed in the unit magnet, and the unit magnet is interposed between the unit magnets by being inserted into the permanent magnet insertion hole,
Between the unit magnets located at both ends of the unit magnet group in the circumferential direction of the rotor and the permanent magnet insertion holes, to reduce cogging torque generated between the stator salient poles and the permanent magnets. A permanent magnet rotating electrical machine, wherein an insulating space is formed. In the permanent magnet rotating electric machine according to claim 1 or 2,
A permanent magnet rotating electrical machine characterized in that at least one of the unit magnets constituting the unit magnet group is different in size from other unit magnets included in the same unit magnet group. In the permanent magnet rotating electric machine according to claim 3,
A permanent magnet rotating electrical machine characterized in that a radial height of the unit magnets located at both ends of a rotor circumferential direction is smaller than a radial height of other unit magnets included in the same unit magnet group . In the permanent magnet rotating electric machine according to claim 3,
The width of the unit magnets positioned at both ends of the rotor in the circumferential direction of the rotor is smaller than the width of the other unit magnets included in the same unit magnet group in the circumferential direction of the rotor. Magnet rotating electric machine.

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